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University of North Carolina
1.
Lauterbach, Christian.
Interactive ray tracing of massive and deformable models.
Degree: Computer Science, 2010, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:ba800545-a564-44b9-9c02-56821f96506d 
► Ray tracing is a fundamental algorithm used for many applications such as computer graphics, geometric simulation, collision detection and line-of-sight computation. Even though the performance…
(more)
▼ Ray tracing is a fundamental algorithm used for many applications such as computer graphics, geometric simulation, collision detection and line-of-sight computation. Even though the performance of ray tracing algorithms scales with the model complexity, the high memory requirements and the use of static hierarchical structures pose problems with massive models and dynamic data-sets. We present several approaches to address these problems based on new acceleration structures and traversal algorithms. We introduce a compact representation for storing the model and hierarchy while ray tracing triangle meshes that can reduce the memory footprint by up to 80%, while maintaining high performance. As a result, can ray trace massive models with hundreds of millions of triangles on workstations with a few gigabytes of memory. We also show how to use bounding volume hierarchies for ray tracing complex models with interactive performance. In order to handle dynamic scenes, we use refitting algorithms and also present highly-parallel GPU-based algorithms to reconstruct the hierarchies. In practice, our method can construct hierarchies for models with hundreds of thousands of triangles at interactive speeds. Finally, we demonstrate several applications that are enabled by these algorithms. Using deformable BVH and fast data parallel techniques, we introduce a geometric sound propagation algorithm that can run on complex deformable scenes interactively and orders of magnitude faster than comparable previous approaches. In addition, we also use these hierarchical algorithms for fast collision detection between deformable models and GPU rendering of shadows on massive models by employing our compact representations for hybrid ray tracing and rasterization.
Advisors/Committee Members: Lauterbach, Christian, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Lauterbach, C. (2010). Interactive ray tracing of massive and deformable models. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:ba800545-a564-44b9-9c02-56821f96506d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lauterbach, Christian. “Interactive ray tracing of massive and deformable models.” 2010. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:ba800545-a564-44b9-9c02-56821f96506d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lauterbach, Christian. “Interactive ray tracing of massive and deformable models.” 2010. Web. 18 Jan 2021.
Vancouver:
Lauterbach C. Interactive ray tracing of massive and deformable models. [Internet] [Thesis]. University of North Carolina; 2010. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:ba800545-a564-44b9-9c02-56821f96506d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lauterbach C. Interactive ray tracing of massive and deformable models. [Thesis]. University of North Carolina; 2010. Available from: https://cdr.lib.unc.edu/record/uuid:ba800545-a564-44b9-9c02-56821f96506d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
2.
Chandak, Anish.
Efficient geometric sound propagation using visibility culling.
Degree: Computer Science, 2011, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:cee9950f-490f-44e3-b7da-5b37348d1e95
► Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering…
(more)
▼ Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering applications such as architectural acoustics. In this thesis, we present geometric sound propagation techniques which are faster than prior methods and map well to upcoming parallel multi-core CPUs. We model specular reflections by using the image-source method and model finite-edge diffraction by using the well-known Biot-Tolstoy-Medwin (BTM) model. We accelerate the computation of specular reflections by applying novel visibility algorithms, FastV and AD-Frustum, which compute visibility from a point. We accelerate finite-edge diffraction modeling by applying a novel visibility algorithm which computes visibility from a region. Our visibility algorithms are based on frustum tracing and exploit recent advances in fast ray-hierarchy intersections, data-parallel computations, and scalable, multi-core algorithms. The AD-Frustum algorithm adapts its computation to the scene complexity and allows small errors in computing specular reflection paths for higher computational efficiency. FastV and our visibility algorithm from a region are general, object-space, conservative visibility algorithms that together significantly reduce the number of image sources compared to other techniques while preserving the same accuracy. Our geometric propagation algorithms are an order of magnitude faster than prior approaches for modeling specular reflections and two to ten times faster for modeling finite-edge diffraction. Our algorithms are interactive, scale almost linearly on multi-core CPUs, and can handle large, complex, and dynamic scenes. We also compare the accuracy of our sound propagation algorithms with other methods. Once sound propagation is performed, it is desirable to listen to the propagated sound in interactive and engineering applications. We can generate smooth, artifact-free output audio signals by applying efficient audio-processing algorithms. We also present the first efficient audio-processing algorithm for scenarios with simultaneously moving source and moving receiver (MS-MR) which incurs less than 25% overhead compared to static source and moving receiver (SS-MR) or moving source and static receiver (MS-SR) scenario.
Advisors/Committee Members: Chandak, Anish, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Chandak, A. (2011). Efficient geometric sound propagation using visibility culling. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:cee9950f-490f-44e3-b7da-5b37348d1e95
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chandak, Anish. “Efficient geometric sound propagation using visibility culling.” 2011. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:cee9950f-490f-44e3-b7da-5b37348d1e95.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chandak, Anish. “Efficient geometric sound propagation using visibility culling.” 2011. Web. 18 Jan 2021.
Vancouver:
Chandak A. Efficient geometric sound propagation using visibility culling. [Internet] [Thesis]. University of North Carolina; 2011. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:cee9950f-490f-44e3-b7da-5b37348d1e95.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chandak A. Efficient geometric sound propagation using visibility culling. [Thesis]. University of North Carolina; 2011. Available from: https://cdr.lib.unc.edu/record/uuid:cee9950f-490f-44e3-b7da-5b37348d1e95
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
3.
Taylor, Micah.
Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments.
Degree: Computer Science, 2014, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:78be5a39-6946-4d60-b1dd-7cb43f5d30e1
► Hearing is an important sense and it is known that rendering sound effects can enhance the level of immersion in virtual environments. Modeling sound waves…
(more)
▼ Hearing is an important sense and it is known that rendering sound effects can enhance the level of immersion in virtual environments. Modeling sound waves is a complex problem, requiring vast computing resources to solve accurately. Prior methods are restricted to static scenes or limited acoustic effects. In this thesis, we present methods to improve the quality and performance of interactive geometric sound propagation in dynamic scenes and precomputation algorithms for acoustic propagation in enormous multi-user virtual environments. We present a method for finding edge diffraction propagation paths on arbitrary 3D scenes for dynamic sources and receivers. Using this algorithm, we present a unified framework for interactive simulation of specular reflections, diffuse reflections, diffraction scattering, and reverberation effects. We also define a guidance algorithm for ray tracing that responds to dynamic environments and reorders queries to minimize simulation time. Our approach works well on modern GPUs and can achieve more than an order of magnitude performance improvement over prior methods. Modern multi-user virtual environments support many types of client devices, and current phones and mobile devices may lack the resources to run acoustic simulations. To provide such devices the benefits of sound simulation, we have developed a precomputation algorithm that efficiently computes and stores acoustic data on a server in the cloud. Using novel algorithms, the server can render enhanced spatial audio in scenes spanning several square kilometers for hundreds of clients in realtime. Our method provides the benefits of immersive audio to collaborative telephony, video games, and multi-user virtual environments.
Advisors/Committee Members: Taylor, Micah, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Taylor, M. (2014). Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:78be5a39-6946-4d60-b1dd-7cb43f5d30e1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Taylor, Micah. “Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments.” 2014. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:78be5a39-6946-4d60-b1dd-7cb43f5d30e1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Taylor, Micah. “Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments.” 2014. Web. 18 Jan 2021.
Vancouver:
Taylor M. Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments. [Internet] [Thesis]. University of North Carolina; 2014. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:78be5a39-6946-4d60-b1dd-7cb43f5d30e1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Taylor M. Interactive Sound Propagation for Massive Multi-user and Dynamic Virtual Environments. [Thesis]. University of North Carolina; 2014. Available from: https://cdr.lib.unc.edu/record/uuid:78be5a39-6946-4d60-b1dd-7cb43f5d30e1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
4.
Pan, Jia.
Efficient configuration space construction and optimization.
Degree: Computer Science, 2013, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:b754f0f1-2f9b-45f8-a750-8a7127d67e3d
► The configuration space is a fundamental concept that is widely used in algorithmic robotics. Many applications in robotics, computer-aided design, and related areas can be…
(more)
▼ The configuration space is a fundamental concept that is widely used in algorithmic robotics. Many applications in robotics, computer-aided design, and related areas can be reduced to computational problems in terms of configuration spaces. In this dissertation, we address three main computational challenges related to configuration spaces: 1) how to efficiently compute an approximate representation of high-dimensional configuration spaces; 2) how to efficiently perform geometric, proximity, and motion planning queries in high dimensional configuration spaces; and 3) how to model uncertainty in configuration spaces represented by noisy sensor data. We present new configuration space construction algorithms based on machine learning and geometric approximation techniques. These algorithms perform collision queries on many configuration samples. The collision query results are used to compute an approximate representation for the configuration space, which quickly converges to the exact configuration space. We highlight the efficiency of our algorithms for penetration depth computation and instance-based motion planning. We also present parallel GPU-based algorithms to accelerate the performance of optimization and search computations in configuration spaces. In particular, we design efficient GPU-based parallel k-nearest neighbor and parallel collision detection algorithms and use these algorithms to accelerate motion planning. In order to extend configuration space algorithms to handle noisy sensor data arising from real-world robotics applications, we model the uncertainty in the configuration space by formulating the collision probabilities for noisy data. We use these algorithms to perform reliable motion planning for the PR2 robot.
Advisors/Committee Members: Pan, Jia, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Pan, J. (2013). Efficient configuration space construction and optimization. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:b754f0f1-2f9b-45f8-a750-8a7127d67e3d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pan, Jia. “Efficient configuration space construction and optimization.” 2013. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:b754f0f1-2f9b-45f8-a750-8a7127d67e3d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pan, Jia. “Efficient configuration space construction and optimization.” 2013. Web. 18 Jan 2021.
Vancouver:
Pan J. Efficient configuration space construction and optimization. [Internet] [Thesis]. University of North Carolina; 2013. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:b754f0f1-2f9b-45f8-a750-8a7127d67e3d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pan J. Efficient configuration space construction and optimization. [Thesis]. University of North Carolina; 2013. Available from: https://cdr.lib.unc.edu/record/uuid:b754f0f1-2f9b-45f8-a750-8a7127d67e3d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
5.
Curtis, Sean.
Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space.
Degree: Computer Science, 2014, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:481dd80b-0059-4e35-b0ab-e91d2cd62591
► We live in a populous world. Furthermore, as social animals, we participate in activities which draw us together into shared spaces – office buildings, city…
(more)
▼ We live in a populous world. Furthermore, as social animals, we participate in activities which draw us together into shared spaces – office buildings, city sidewalks, parks, events (e.g., religious, sporting, or political), etc. Models that can predict how crowds of humans behave in such settings would be valuable in allowing us to analyze the designs for novel environments and anticipate issues with space utility and safety. They would also better enable robots to safely work in a common environment with humans. Furthermore, credible simulation of crowds of humans would allow us to populate virtual worlds, helping to increase the immersive properties of virtual reality or entertainment applications. We propose a new model for pedestrian crowd simulation: Pedestrian Velocity Obstacles (PedVO). PedVO is based on Optimal Reciprocal Collision Avoidance (ORCA), a local navigation algorithm for computing optimal feasible velocities which simultaneously avoid collisions while still allowing the agents to progress toward their individual goals. PedVO extends ORCA by introducing new models of pedestrian behavior and relationships in conjunction with a modified geometric optimization planning technique to efficiently simulate agents with improved human-like behaviors. PedVO introduces asymmetric relationships between agents through two complementary techniques: Composite Agents and Right of Way. The former exploits the underlying collision avoidance mechanism to encode abstract factors and the latter modifies the optimization algorithm's constraint definition to enforce asymmetric coordination. PedVO further changes the optimization algorithm to more fully encode the agent's knowledge of its environment, allowing the agent to make more intelligent decisions, leading to a better utilization of space and improved flow. PedVO incorporates a new model, which works in conjunction with the local planning algorithm, to introduce a ubiquitous density-sensitive behavior observed in human crowds – the so-called "fundamental diagram." We also provide a physically-plausible, interactive model for simulating walking motion to support the computed agent trajectories. We evaluate these techniques by simulating various scenarios, such as pedestrian experiments and a challenging real-world scenario: simulating the performance of the Tawaf, an aspect of the Muslim Hajj.
Advisors/Committee Members: Curtis, Sean, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
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APA (6th Edition):
Curtis, S. (2014). Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:481dd80b-0059-4e35-b0ab-e91d2cd62591
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Curtis, Sean. “Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space.” 2014. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:481dd80b-0059-4e35-b0ab-e91d2cd62591.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Curtis, Sean. “Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space.” 2014. Web. 18 Jan 2021.
Vancouver:
Curtis S. Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space. [Internet] [Thesis]. University of North Carolina; 2014. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:481dd80b-0059-4e35-b0ab-e91d2cd62591.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Curtis S. Pedestrian velocity obstacles: pedestrian simulation through reasoning in velocity space. [Thesis]. University of North Carolina; 2014. Available from: https://cdr.lib.unc.edu/record/uuid:481dd80b-0059-4e35-b0ab-e91d2cd62591
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
6.
Morales, Nicolas.
Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design.
Degree: Computer Science, 2018, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:503e5652-69d4-4816-b93a-b4cbbe45feff
► Acoustic phenomena have a large impact on our everyday lives, from influencing our enjoyment of music in a concert hall, to affecting our concentration at…
(more)
▼ Acoustic phenomena have a large impact on our everyday lives, from influencing our enjoyment of music in a concert hall, to affecting our concentration at school or work, to potentially negatively impacting our health through deafening noises. The sound that reaches our ears is absorbed, reflected, and filtered by the shape, topology, and materials present in the environment. However, many computer simulation techniques for solving these sound propagation problems are either computationally expensive or inaccurate. Additionally, the costs of some methods are dramatically increased in design optimization processes in which several iterations of sound propagation evaluation are necessary.
The primary goal of this dissertation is to present techniques for efficiently solving the sound propagation problem and related optimization problems for computer-aided design. First, we propose a parallel method for solving large acoustic propagation problems, scalable to tens of thousands of cores. Second, we present two novel techniques for optimizing certain acoustic characteristics such as reverberation time or sound clarity using wave-based sound propagation. Finally, we show how hybrid sound propagation algorithms can be used to improve the performance of acoustic optimization problems and present two algorithms for noise minimization and speech intelligibility improvement that use this hybrid approach.
All the algorithms we present are evaluated on various benchmarks that are computer models of architectural scenes. These benchmarks include challenging environments for existing sound propagation algorithms, such as large indoor or outdoor scenes, structural complex scenes, or the prevalence of difficult-to-model sound propagation phenomena. Using the techniques put forth in this dissertation, we can solve many challenging sound propagation and optimization problems on the scenes in an efficient manner. We are able to accurately model sound propagation using wave-based approaches up to \SI{10}{\kilo\hertz} (the full range of human speech) and for the full range of human hearing (22kHz) using our hybrid approach. Our noise minimization methods show improvements of up to 13dB in noise reduction on some scenes, and we show a 71% improvement in speech intelligibility using our algorithm.
Advisors/Committee Members: Morales, Nicolas, Manocha, Dinesh, Manocha, Dinesh, Lin, Ming, Bishop, Gary, Jing, Yun, Prins, Jan.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Morales, N. (2018). Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:503e5652-69d4-4816-b93a-b4cbbe45feff
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Morales, Nicolas. “Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design.” 2018. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:503e5652-69d4-4816-b93a-b4cbbe45feff.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Morales, Nicolas. “Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design.” 2018. Web. 18 Jan 2021.
Vancouver:
Morales N. Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design. [Internet] [Thesis]. University of North Carolina; 2018. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:503e5652-69d4-4816-b93a-b4cbbe45feff.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Morales N. Efficient Wave-based Sound Propagation and Optimization for Computer-Aided Design. [Thesis]. University of North Carolina; 2018. Available from: https://cdr.lib.unc.edu/record/uuid:503e5652-69d4-4816-b93a-b4cbbe45feff
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
7.
Antani, Lakulish.
Interactive Sound Propagation using Precomputation and Statistical Approximations.
Degree: Computer Science, 2013, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:bba013ea-33c7-4d4b-983c-acd002e50d26
► Acoustic phenomena such as early reflections, diffraction, and reverberation have been shown to improve the user experience in interactive virtual environments and video games. These…
(more)
▼ Acoustic phenomena such as early reflections, diffraction, and reverberation have been shown to improve the user experience in interactive virtual environments and video games. These effects arise due to repeated interactions between sound waves and objects in the environment. In interactive applications, these effects must be simulated within a prescribed time budget. We present two complementary approaches for computing such acoustic effects in real time, with plausible variation in the sound field throughout the scene. The first approach, Precomputed Acoustic Radiance Transfer, precomputes a matrix that accounts for multiple acoustic interactions between all scene objects. The matrix is used at run time to provide sound propagation effects that vary smoothly as sources and listeners move. The second approach couples two techniques – Ambient Reverberance, and Aural Proxies – to provide approximate sound propagation effects in real time, based on only the portion of the environment immediately visible to the listener. These approaches lie at different ends of a space of interactive sound propagation techniques for modeling sound propagation effects in interactive applications. The first approach emphasizes accuracy by modeling acoustic interactions between all parts of the scene; the second approach emphasizes efficiency by only taking the local environment of the listener into account. These methods have been used to efficiently generate acoustic walkthroughs of architectural models. They have also been integrated into a modern game engine, and can enable realistic, interactive sound propagation on commodity desktop PCs.
Advisors/Committee Members: Antani, Lakulish, Manocha, Dinesh, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Antani, L. (2013). Interactive Sound Propagation using Precomputation and Statistical Approximations. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:bba013ea-33c7-4d4b-983c-acd002e50d26
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Antani, Lakulish. “Interactive Sound Propagation using Precomputation and Statistical Approximations.” 2013. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:bba013ea-33c7-4d4b-983c-acd002e50d26.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Antani, Lakulish. “Interactive Sound Propagation using Precomputation and Statistical Approximations.” 2013. Web. 18 Jan 2021.
Vancouver:
Antani L. Interactive Sound Propagation using Precomputation and Statistical Approximations. [Internet] [Thesis]. University of North Carolina; 2013. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:bba013ea-33c7-4d4b-983c-acd002e50d26.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Antani L. Interactive Sound Propagation using Precomputation and Statistical Approximations. [Thesis]. University of North Carolina; 2013. Available from: https://cdr.lib.unc.edu/record/uuid:bba013ea-33c7-4d4b-983c-acd002e50d26
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
8.
Gayle, Thomas Russell.
Physically-based sampling for motion planning.
Degree: Computer Science, 2010, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:78993b24-4fc9-4508-9a45-912d9f96bbb0
► Motion planning is a fundamental problem with applications in a wide variety of areas including robotics, computer graphics, animation, virtual prototyping, medical simulations, industrial simulations,…
(more)
▼ Motion planning is a fundamental problem with applications in a wide variety of areas including robotics, computer graphics, animation, virtual prototyping, medical simulations, industrial simulations, and trac planning. Despite being an active area of research for nearly four decades, prior motion planning algorithms are unable to provide adequate solutions that satisfy the constraints that arise in these applications. We present a novel approach based on physics-based sampling for motion planning that can compute collision-free paths while also satisfying many physical constraints. Our planning algorithms use constrained simulation to generate samples which are biased in the direction of the nal goal positions of the agent or agents. The underlying simulation core implicitly incorporates kinematics and dynamics of the robot or agent as constraints or as part of the motion model itself. Thus, the resulting motion is smooth and physically-plausible for both single robot and multi-robot planning. We apply our approach to planning of deformable soft-body agents via the use of graphics hardware accelerated interference queries. We highlight the approach with a case study on pre-operative planning for liver chemoembolization. Next, we apply it to the case of highly articulated serial chains. Through dynamic dimensionality reduction and optimized collision response, we can successfully plan the motion of \snake-like robots in a practical amount of time despite the high number of degrees of freedom in the problem. Finally, we show the use of the approach for a large number of bodies in dynamic environments. By applying our approach to both global and local interactions between agents, we can successfully plan for thousands of simple robots in real-world scenarios. We demonstrate their application to large crowd simulations.
Advisors/Committee Members: Gayle, Thomas Russell, Manocha, Dinesh, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Gayle, T. R. (2010). Physically-based sampling for motion planning. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:78993b24-4fc9-4508-9a45-912d9f96bbb0
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gayle, Thomas Russell. “Physically-based sampling for motion planning.” 2010. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:78993b24-4fc9-4508-9a45-912d9f96bbb0.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gayle, Thomas Russell. “Physically-based sampling for motion planning.” 2010. Web. 18 Jan 2021.
Vancouver:
Gayle TR. Physically-based sampling for motion planning. [Internet] [Thesis]. University of North Carolina; 2010. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:78993b24-4fc9-4508-9a45-912d9f96bbb0.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gayle TR. Physically-based sampling for motion planning. [Thesis]. University of North Carolina; 2010. Available from: https://cdr.lib.unc.edu/record/uuid:78993b24-4fc9-4508-9a45-912d9f96bbb0
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
9.
Mehra, Ravish.
Efficient Techniques for Wave-based Sound Propagation in Interactive Applications.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:b1753c5b-c241-404d-a5b9-5aee6b291101
► Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the…
(more)
▼ Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the final point of arrival at the listener. Sound is a pressure wave produced by mechanical vibration of a surface that propagates through a medium such as air or water, and the problem of sound propagation can be formulated mathematically as a second-order partial differential equation called the wave equation. Accurate techniques based on solving the wave equation, also called the wave-based techniques, are too expensive computationally and memory-wise. Therefore, these techniques face many challenges in terms of their applicability in interactive applications including sound propagation in large environments, time-varying source and listener directivity, and high simulation cost for mid-frequencies. In this dissertation, we propose a set of efficient wave-based sound propagation techniques that solve these three challenges and enable the use of wave-based sound propagation in interactive applications. Firstly, we propose a novel equivalent source technique for interactive wave-based sound propagation in large scenes spanning hundreds of meters. It is based on the equivalent source theory used for solving radiation and scattering problems in acoustics and electromagnetics. Instead of using a volumetric or surface-based approach, this technique takes an object-centric approach to sound propagation. The proposed equivalent source technique generates realistic acoustic effects and takes orders of magnitude less runtime memory compared to prior wave-based techniques. Secondly, we present an efficient framework for handling time-varying source and listener directivity for interactive wave-based sound propagation. The source directivity is represented as a linear combination of elementary spherical harmonic sources. This spherical harmonic-based representation of source directivity can support analytical, data-driven, rotating or time-varying directivity function at runtime. Unlike previous approaches, the listener directivity approach can be used to compute spatial audio (3D audio) for a moving, rotating listener at interactive rates. Lastly, we propose an efficient GPU-based time-domain solver for the wave equation that enables wave simulation up to the mid-frequency range in tens of minutes on a desktop computer. It is demonstrated that by carefully mapping all the components of the wave simulator to match the parallel processing capabilities of the graphics processors, significant improvement in performance can be achieved compared to the CPU-based simulators, while maintaining numerical accuracy. We validate these techniques with offline numerical simulations and measured data recorded in an outdoor scene. We present results of preliminary user evaluations conducted to study the impact of these techniques on user's immersion in virtual environment. We have integrated these techniques with the Half-Life 2 game engine, Oculus Rift head-mounted display, and Xbox game…
Advisors/Committee Members: Mehra, Ravish, Manocha, Dinesh, Lin, Ming, Lastra, Anselmo, Whitted, Turner, Niethammer, Marc.
Subjects/Keywords: Computer science; Sound; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Mehra, R. (2015). Efficient Techniques for Wave-based Sound Propagation in Interactive Applications. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:b1753c5b-c241-404d-a5b9-5aee6b291101
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mehra, Ravish. “Efficient Techniques for Wave-based Sound Propagation in Interactive Applications.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:b1753c5b-c241-404d-a5b9-5aee6b291101.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mehra, Ravish. “Efficient Techniques for Wave-based Sound Propagation in Interactive Applications.” 2015. Web. 18 Jan 2021.
Vancouver:
Mehra R. Efficient Techniques for Wave-based Sound Propagation in Interactive Applications. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:b1753c5b-c241-404d-a5b9-5aee6b291101.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mehra R. Efficient Techniques for Wave-based Sound Propagation in Interactive Applications. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:b1753c5b-c241-404d-a5b9-5aee6b291101
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
10.
Brown, Shawn.
Case Studies on Optimizing Algorithms for GPU Architectures.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:691f0030-dca5-4f49-9fb4-4b470cbf464c
► Modern GPUs are complex, massively multi-threaded, and high-performance. Programmers naturally gravitate towards taking advantage of this high performance for achieving faster results. However, in order…
(more)
▼ Modern GPUs are complex, massively multi-threaded, and high-performance. Programmers naturally gravitate towards taking advantage of this high performance for achieving faster results. However, in order to do so successfully, programmers must first understand and then master a new set of skills – writing parallel code, using different types of parallelism, adapting to GPU architectural features, and understanding issues that limit performance. In order to ease this learning process and help GPU programmers become productive more quickly, this dissertation introduces three data access skeletons (DASks) – Block, Column, and Row – and two block access skeletons (BASks) – Block-By-Block and Warp-by-Warp. Each “skeleton” provides a high-performance implementation framework that partitions data arrays into data blocks and then iterates over those blocks. The programmer must still write “body” methods on individual data blocks to solve their specific problem. These skeletons provide efficient machine dependent data access patterns for use on GPUs. DASks group n data elements into m fixed size data blocks. These m data block are then partitioned across p thread blocks using a 1D or 2D layout pattern. The fixed-size data blocks are parameterized using three C++ template parameters – nWork, WarpSize, and nWarps. Generic programming techniques use these three parameters to enable performance experiments on three different types of parallelism – instruction-level parallelism (ILP), data-level parallelism (DLP), and thread-level parallelism (TLP). These different DASks and BASks are introduced using a simple memory I/O (Copy) case study. A nearest neighbor search case study resulted in the development of DASKs and BASks but does not use these skeletons itself. Three additional case studies – Reduce/Scan, Histogram, and Radix Sort – demonstrate DASks and BASks in action on parallel primitives and also provides more valuable performance lessons.
Advisors/Committee Members: Brown, Shawn, Snoeyink, Jack, Lastra, Anselmo, Manocha, Dinesh, Nyland, Lars, Prins, Jan, Snoeyink, Jack.
Subjects/Keywords: Computer science; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Brown, S. (2015). Case Studies on Optimizing Algorithms for GPU Architectures. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:691f0030-dca5-4f49-9fb4-4b470cbf464c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Brown, Shawn. “Case Studies on Optimizing Algorithms for GPU Architectures.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:691f0030-dca5-4f49-9fb4-4b470cbf464c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Brown, Shawn. “Case Studies on Optimizing Algorithms for GPU Architectures.” 2015. Web. 18 Jan 2021.
Vancouver:
Brown S. Case Studies on Optimizing Algorithms for GPU Architectures. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:691f0030-dca5-4f49-9fb4-4b470cbf464c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Brown S. Case Studies on Optimizing Algorithms for GPU Architectures. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:691f0030-dca5-4f49-9fb4-4b470cbf464c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
11.
Mo, Qi.
Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:c4f2c37e-cb38-414e-a1b5-65a0692095a2
► Refractive media is ubiquitous in the natural world, and light and sound propagation in refractive media leads to characteristic visual and acoustic phenomena. Those phenomena…
(more)
▼ Refractive media is ubiquitous in the natural world, and light and sound propagation in refractive media leads to characteristic visual and acoustic phenomena. Those phenomena are critical for engineering applications to simulate with high accuracy requirements, and they can add to the perceived realism and sense of immersion for training and entertainment applications. Existing methods can be roughly divided into two categories with regard to their handling of propagation in refractive media; first category of methods makes simplifying assumption about the media or entirely excludes the consideration of refraction in order to achieve efficient propagation, while the second category of methods accommodates refraction but remains computationally expensive. In this dissertation, we present algorithms that achieve efficient and scalable propagation simulation of light and sound in refractive media, handling fully general media and scene configurations. Our approaches are based on ray tracing, which traditionally assumes homogeneous media and rectilinear rays. We replace the rectilinear rays with analytic ray curves as tracing primitives, which represent closed-form trajectory solutions based on assumptions of a locally constant media gradient. For general media profiles, the media can be spatially decomposed into explicit or implicit cells, within which the media gradient can be assumed constant, leading to an analytic ray path within that cell. Ray traversal of the media can therefore proceed in segments of ray curves. The first source of speedup comes from the fact that for smooth media, a locally constant media gradient assumption tends to stay valid for a larger area than the assumption of a locally constant media property. The second source of speedup is the constant-cost intersection computation of the analytic ray curves with planar surfaces. The third source of speedup comes from making the size of each cell and therefore each ray curve segment adaptive to the magnitude of media gradient. Interactions with boundary surfaces in the scene can be efficiently handled within this framework in two alternative approaches. For static scenes, boundary surfaces can be embedded into the explicit mesh of tetrahedral cells, and the mesh can be traversed and the embedded surfaces intersected with by the analytic ray curve in a unified manner. For dynamic scenes, implicit cells are used for media traversal, and boundary surface intersections can be handled separately by constructing hierarchical acceleration structures adapted from rectilinear ray tracer. The efficient handling of boundary surfaces is the fourth source of speedup of our propagation path computation. We demonstrate over two orders-of-magnitude performance improvement of our analytic ray tracing algorithms over prior methods for refractive light and sound propagation. We additionally present a complete sound-propagation simulation solution that matches the path computation efficiency achieved by the ray curve tracer. We develop efficient pressure computation…
Advisors/Committee Members: Mo, Qi, Manocha, Dinesh, Bishop, Gary, Lin, Ming, Lastra, Anselmo, Niethammer, Marc.
Subjects/Keywords: Computer science; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mo, Q. (2015). Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:c4f2c37e-cb38-414e-a1b5-65a0692095a2
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mo, Qi. “Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:c4f2c37e-cb38-414e-a1b5-65a0692095a2.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mo, Qi. “Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer.” 2015. Web. 18 Jan 2021.
Vancouver:
Mo Q. Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:c4f2c37e-cb38-414e-a1b5-65a0692095a2.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mo Q. Efficient Light and Sound Propagation in Refractive Media with Analytic Ray Curve Tracer. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:c4f2c37e-cb38-414e-a1b5-65a0692095a2
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
12.
Kim, Sujeong.
Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:64b49566-57aa-4e6d-86e9-9c408794be4b
► The problem of simulating a large number of independent entities, interacting with each other and moving through a shared space, has received considerable attention in…
(more)
▼ The problem of simulating a large number of independent entities, interacting with each other and moving through a shared space, has received considerable attention in computer graphics, biomechanics, psychology, robotics, architectural design, and pedestrian dynamics. One of the major challenges is to simulate the dynamic nature, variety, and subtle aspects of real-world crowd motions. Furthermore, many applications require the capabilities to simulate these movements and behaviors at interactive rates. In this thesis, we present interactive methods for computing trajectory-level behaviors that capture various aspects of human crowds. At a microscopic level, we address the problem of modeling the local interactions. First, we simulate dynamic patterns of crowd behaviors using Attribution theory and General Adaptation Syndrome theory from psychology. Our model accounts for permanent, stable disposition and the dynamic nature of human behaviors that change in response to the situation. Second, we model physics-based interactions in dense crowds by combining velocity-based collision avoidance algorithms with external forces. Our approach is capable of modeling both physical forces and interactions between agents and obstacles, while also allowing the agents to anticipate and avoid upcoming collisions during local navigation. We also address the problem at macroscopic level by modeling high-level aspects of human crowd behaviors. We present an automated scheme for learning and predicting individual behaviors from real-world crowd trajectories. Our approach is based on Bayesian learning algorithms combined with a velocity-based local collision avoidance model. We further extend our method to learn time-varying trajectory behavior patterns from pedestrian trajectories. These behavior patterns can be combined with local navigation algorithms to generate crowd behaviors that are similar to those observed in real-world videos. We highlight their performance for pedestrian navigation, architectural design and generating dynamic behaviors for virtual environments.
Advisors/Committee Members: Kim, Sujeong, Manocha, Dinesh, Lin, Ming, Frahm, Jan-Michael, Guy, Stephen, O'O'Sullivan, Carol.
Subjects/Keywords: Computer science; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kim, S. (2015). Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:64b49566-57aa-4e6d-86e9-9c408794be4b
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kim, Sujeong. “Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:64b49566-57aa-4e6d-86e9-9c408794be4b.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kim, Sujeong. “Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors.” 2015. Web. 18 Jan 2021.
Vancouver:
Kim S. Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:64b49566-57aa-4e6d-86e9-9c408794be4b.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kim S. Velocity-Space Reasoning for Interactive Simulation of Dynamic Crowd Behaviors. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:64b49566-57aa-4e6d-86e9-9c408794be4b
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
13.
Schissler, Carl.
Efficient Interactive Sound Propagation in Dynamic Environments.
Degree: Computer Science, 2017, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:8f1a9c3e-6f82-4fa6-a9d2-d6ebbe258da1
► The physical phenomenon of sound is ubiquitous in our everyday life and is an important component of immersion in interactive virtual reality applications. Sound propagation…
(more)
▼ The physical phenomenon of sound is ubiquitous in our everyday life and is an important component of immersion in interactive virtual reality applications. Sound propagation involves modeling how sound is emitted from a source, interacts with the environment, and is received by a listener. Previous techniques for computing interactive sound propagation in dynamic scenes are based on geometric algorithms such as ray tracing. However, the performance and quality of these algorithms is strongly dependent on the number of rays traced. In addition, it is difficult to acquire acoustic material properties. It is also challenging to efficiently compute spatial sound effects from the output of ray tracing-based sound propagation. These problems lead to increased latency and less plausible sound in dynamic interactive environments. In this dissertation, we propose three approaches with the goal of addressing these challenges. First, we present an approach that utilizes temporal coherence in the sound field to reuse computation from previous simulation time steps. Secondly, we present a framework for the automatic acquisition of acoustic material properties using visual and audio measurements of real-world environments. Finally, we propose efficient techniques for computing directional spatial sound for sound propagation with low latency using head-related transfer functions (HRTF). We have evaluated both the performance and subjective impact of these techniques on a variety of complex dynamic indoor and outdoor environments and observe an order-of-magnitude speedup over previous approaches. The accuracy of our approaches has been validated against real-world measurements and previous methods. The proposed techniques enable interactive simulation of sound propagation in complex multi-source dynamic environments.
Advisors/Committee Members: Schissler, Carl, Manocha, Dinesh, Lin, Ming, Bishop, Gary, Whitted, Turner, Mehra, Ravish.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Schissler, C. (2017). Efficient Interactive Sound Propagation in Dynamic Environments. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:8f1a9c3e-6f82-4fa6-a9d2-d6ebbe258da1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Schissler, Carl. “Efficient Interactive Sound Propagation in Dynamic Environments.” 2017. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:8f1a9c3e-6f82-4fa6-a9d2-d6ebbe258da1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Schissler, Carl. “Efficient Interactive Sound Propagation in Dynamic Environments.” 2017. Web. 18 Jan 2021.
Vancouver:
Schissler C. Efficient Interactive Sound Propagation in Dynamic Environments. [Internet] [Thesis]. University of North Carolina; 2017. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:8f1a9c3e-6f82-4fa6-a9d2-d6ebbe258da1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Schissler C. Efficient Interactive Sound Propagation in Dynamic Environments. [Thesis]. University of North Carolina; 2017. Available from: https://cdr.lib.unc.edu/record/uuid:8f1a9c3e-6f82-4fa6-a9d2-d6ebbe258da1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
14.
Bera, Aniket.
Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds.
Degree: Computer Science, 2017, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:9d6e3a5a-e96b-47e5-960c-cb5068d90605
► The ability to automatically recognize human motions and behaviors is a key skill for autonomous machines to exhibit to interact intelligently with a human-inhabited environment.…
(more)
▼ The ability to automatically recognize human motions and behaviors is a key skill for autonomous machines to exhibit to interact intelligently with a human-inhabited environment. The capabilities autonomous machines should have include computing the motion trajectory of each pedestrian in a crowd, predicting his or her position in the near future, and analyzing the personality characteristics of the pedestrian. Such techniques are frequently used for collision-free robot navigation, data-driven crowd simulation, and crowd surveillance applications. However, prior methods for these problems have been restricted to low-density or sparse crowds where the pedestrian movement is modeled using simple motion models.
In this thesis, we present several interactive algorithms to extract pedestrian trajectories from videos in dense crowds. Our approach combines different pedestrian motion models with particle tracking and mixture models and can obtain an average of 20% improvement in accuracy in medium-density crowds over prior work. We compute the pedestrian dynamics from these trajectories using Bayesian learning techniques and combine them with global methods for long-term pedestrian prediction in densely crowded settings. Finally, we combine these techniques with Personality Trait Theory to automatically classify the dynamic behavior or the personality of a pedestrian based on his or her movements in a crowded scene. The resulting algorithms are robust and can handle sparse and noisy motion trajectories. We demonstrate the benefits of our long-term prediction and behavior classification methods in dense crowds and highlight the benefits over prior techniques.
We highlight the performance of our novel algorithms on three different applications. The first application is interactive data-driven crowd simulation, which includes crowd replication as well as the combination of pedestrian behaviors from different videos. Secondly, we combine the prediction scheme with proxemic characteristics from psychology and use them to perform socially-aware navigation. Finally, we present novel techniques for anomaly detection in low-to medium-density crowd videos using trajectory-level behavior learning.
Advisors/Committee Members: Bera, Aniket, Manocha, Dinesh, Lin, Ming, Alterovitz, Ron, Galoppo, Nico, O'Sullivan, Carol.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Bera, A. (2017). Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:9d6e3a5a-e96b-47e5-960c-cb5068d90605
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Bera, Aniket. “Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds.” 2017. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:9d6e3a5a-e96b-47e5-960c-cb5068d90605.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bera, Aniket. “Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds.” 2017. Web. 18 Jan 2021.
Vancouver:
Bera A. Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds. [Internet] [Thesis]. University of North Carolina; 2017. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:9d6e3a5a-e96b-47e5-960c-cb5068d90605.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bera A. Interactive Tracking, Prediction, and Behavior Learning of Pedestrians in Dense Crowds. [Thesis]. University of North Carolina; 2017. Available from: https://cdr.lib.unc.edu/record/uuid:9d6e3a5a-e96b-47e5-960c-cb5068d90605
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
15.
Bowen, Chris.
Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution.
Degree: Computer Science, 2018, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:3e8f2b19-5574-4411-a0a3-89bf7918ffde
► Robots have the potential to assist people with a variety of everyday tasks, but to achieve that potential robots require software capable of planning and…
(more)
▼ Robots have the potential to assist people with a variety of everyday tasks, but to achieve that potential robots require software capable of planning and executing motions in cluttered environments. To address this, over the past few decades, roboticists have developed numerous methods for planning motions to avoid obstacles with increasingly stronger guarantees, from probabilistic completeness to asymptotic optimality. Some of these methods have even considered the types of constraints that must be satisfied to perform useful tasks, but these constraints must generally be manually specified. In recent years, there has been a resurgence of methods for automatic learning of tasks from human-provided demonstrations. Unfortunately, these two fields, task learning and motion planning, have evolved largely separate from one another, and the learned models are often not usable by motion planners.
In this thesis, we aim to bridge the gap between robot task learning and motion planning by employing a learned task model that can subsequently be leveraged by an asymptotically-optimal motion planner to autonomously execute the task. First, we show that application of a motion planner enables task performance while avoiding novel obstacles and extend this to dynamic environments by replanning at reactive rates. Second, we generalize the method to accommodate time-invariant model parameters, allowing more information to be gleaned from the demonstrations. Third, we describe a more principled approach to temporal registration for such learning methods that mirrors the ultimate integration with a motion planner and often reduces the number of demonstrations required.
Finally, we extend this framework to the domain of mobile manipulation. We empirically evaluate each of these contributions on multiple household tasks using the Aldebaran Nao, Rethink Robotics Baxter, and Fetch mobile manipulator robots to show that these approaches improve task execution success rates and reduce the amount of human-provided information required.
Advisors/Committee Members: Bowen, Chris, Alterovitz, Ron, Berg, Alex, Hauser, Kris, Jojic, Vladimir, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Bowen, C. (2018). Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:3e8f2b19-5574-4411-a0a3-89bf7918ffde
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Bowen, Chris. “Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution.” 2018. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:3e8f2b19-5574-4411-a0a3-89bf7918ffde.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bowen, Chris. “Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution.” 2018. Web. 18 Jan 2021.
Vancouver:
Bowen C. Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution. [Internet] [Thesis]. University of North Carolina; 2018. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:3e8f2b19-5574-4411-a0a3-89bf7918ffde.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bowen C. Robots that Learn and Plan — Unifying Robot Learning and Motion Planning for Generalized Task Execution. [Thesis]. University of North Carolina; 2018. Available from: https://cdr.lib.unc.edu/record/uuid:3e8f2b19-5574-4411-a0a3-89bf7918ffde
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
16.
Ren, Zhimin.
Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction.
Degree: Computer Science, 2014, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:483c6a27-40aa-468f-9876-60658c9f4bfd
► An immersive experience in virtual environments requires realistic auditory feedback that is closely coupled with other modalities, such as vision and touch. This is particularly…
(more)
▼ An immersive experience in virtual environments requires realistic auditory feedback that is closely coupled with other modalities, such as vision and touch. This is particularly challenging for real-time applications due to its stringent computational requirement. In this dissertation, I present and evaluate effective real-time physically based sound synthesis models that integrate visual and touch data and apply them to create richly varying multimodal interaction. I first propose an efficient contact sound synthesis technique that accounts for texture information used for visual rendering and greatly reinforces cross-modal perception. Secondly, I present both empirical and psychoacoustic approaches that formally study the geometry-invariant property of the commonly used material model in real-time sound synthesis. Based on this property, I design a novel example-based material parameter estimation framework that automatically creates synthetic sound effects naturally controlled by complex geometry and dynamics in visual simulation. Lastly, I translate user touch input captured on commodity multi-touch devices to physical performance models that drive both visual and auditory rendering. This novel multimodal interaction is demonstrated in a virtual musical instrument application on both a large-size tabletop and mobile tablet devices, and evaluated through pilot studies. Such an application offers capabilities for intuitive and expressive music playing, rapid prototyping of virtual instruments, and active exploration of sound effects determined by various physical parameters.
Advisors/Committee Members: Ren, Zhimin, Lin, Ming, Manocha, Dinesh, Bishop, Gary, Klatzky, Roberta, Raghuvanshi, Nikunj.
Subjects/Keywords: Computer science; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Ren, Z. (2014). Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:483c6a27-40aa-468f-9876-60658c9f4bfd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ren, Zhimin. “Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction.” 2014. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:483c6a27-40aa-468f-9876-60658c9f4bfd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ren, Zhimin. “Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction.” 2014. Web. 18 Jan 2021.
Vancouver:
Ren Z. Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction. [Internet] [Thesis]. University of North Carolina; 2014. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:483c6a27-40aa-468f-9876-60658c9f4bfd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ren Z. Real-Time Physically Based Sound Synthesis and Application in Multimodal Interaction. [Thesis]. University of North Carolina; 2014. Available from: https://cdr.lib.unc.edu/record/uuid:483c6a27-40aa-468f-9876-60658c9f4bfd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
17.
Snape, Jamie Robert.
Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters.
Degree: Computer Science, 2012, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:0571cc57-56d9-4f92-8087-846154a71345
► The navigation of multiple mobile robots or virtual agents through environments containing static and dynamic obstacles to specified goal locations is an important problem in…
(more)
▼ The navigation of multiple mobile robots or virtual agents through environments containing static and dynamic obstacles to specified goal locations is an important problem in mobile robotics, many video games, and simulated environments. Moreover, technological advances in mobile robot hardware and video games consoles have allowed increasing numbers of mobile robots or virtual agents to navigate shared environments simultaneously. However, coordinating the navigation of large groups of mobile robots or virtual agents remains a difficult task. Kinematic and dynamic constraints and the effects of sensor and actuator uncertainty exaggerate the challenge of navigating multiple physical mobile robots, and video games players demand plausible motion and an ever increasing visual fidelity of virtual agents without sacrificing frame rate. We present new methods for navigating multiple mobile robots or virtual agents through shared environments, each using formulations based on velocity obstacles. These include algorithms that allow navigation through environments in two-dimensional or three-dimensional workspaces containing both static and dynamic obstacles without collisions or oscillations. Each mobile robot or virtual agent senses its surroundings and acts independently, without central coordination or inter-communication with its neighbors, implicitly assuming the neighbors use the same navigation strategy based on the notion of reciprocity. We use the position, velocity, and physical extent of neighboring mobile robots or virtual agents to compute their future trajectories to avoid collisions locally and show that, in principle, it is possible to theoretically guarantee that the motion of each mobile robot or virtual agent is smooth. Moreover, we demonstrate direct, collision-free, and oscillation-free navigation in experiments using physical iRobot Create mobile robots, simulations of multiple differential-drive robots or simple-airplanes, and video games levels containing hundreds of virtual agents.
Advisors/Committee Members: Snape, Jamie Robert, Manocha, Dinesh, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Snape, J. R. (2012). Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:0571cc57-56d9-4f92-8087-846154a71345
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Snape, Jamie Robert. “Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters.” 2012. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:0571cc57-56d9-4f92-8087-846154a71345.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Snape, Jamie Robert. “Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters.” 2012. Web. 18 Jan 2021.
Vancouver:
Snape JR. Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters. [Internet] [Thesis]. University of North Carolina; 2012. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:0571cc57-56d9-4f92-8087-846154a71345.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Snape JR. Smooth and Collision-Free Navigation for Multiple Mobile Robots and Video Game Characters. [Thesis]. University of North Carolina; 2012. Available from: https://cdr.lib.unc.edu/record/uuid:0571cc57-56d9-4f92-8087-846154a71345
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
18.
Krajcevski, Pavel.
Improved Encoding for Compressed Textures.
Degree: Computer Science, 2016, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:8be0e9e0-06aa-427c-a00c-dc8ec11171ae
► For the past few decades, graphics hardware has supported mapping a two dimensional image, or texture, onto a three dimensional surface to add detail during…
(more)
▼ For the past few decades, graphics hardware has supported mapping a two dimensional image, or texture, onto a three dimensional surface to add detail during rendering. The complexity of modern applications using interactive graphics hardware have created an explosion of the amount of data needed to represent these images. In order to alleviate the amount of memory required to store and transmit textures, graphics hardware manufacturers have introduced hardware decompression units into the texturing pipeline. Textures may now be stored as compressed in memory and decoded at run-time in order to access the pixel data. In order to encode images to be used with these hardware features, many compression algorithms are run offline as a preprocessing step, often times the most time-consuming step in the asset preparation pipeline. This research presents several techniques to quickly serve compressed texture data. With the goal of interactive compression rates while maintaining compression quality, three algorithms are presented in the class of endpoint compression formats. The first uses intensity dilation to estimate compression parameters for low-frequency signal-modulated compressed textures and offers up to a 3X improvement in compression speed. The second, FasTC, shows that by estimating the final compression parameters, partition-based formats can choose an approximate partitioning and offer orders of magnitude faster encoding speed. The third, SegTC, shows additional improvement over selecting a partitioning by using a global segmentation to find the boundaries between image features. This segmentation offers an additional 2X improvement over FasTC while maintaining similar compressed quality. Also presented is a case study in using texture compression to benefit two dimensional concave path rendering. Compressing pixel coverage textures used for compositing yields both an increase in rendering speed and a decrease in storage overhead. Additionally an algorithm is presented that uses a single layer of indirection to adaptively select the block size compressed for each texture, giving a 2X increase in compression ratio for textures of mixed detail. Finally, a texture storage representation that is decoded at runtime on the GPU is presented. The decoded texture is still compressed for graphics hardware but uses 2X fewer bytes for storage and network bandwidth.
Advisors/Committee Members: Krajcevski, Pavel, Manocha, Dinesh, Lin, Ming, Mayer-Patel, Ketan, Pharr, Matt, Whitted, Turner.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Krajcevski, P. (2016). Improved Encoding for Compressed Textures. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:8be0e9e0-06aa-427c-a00c-dc8ec11171ae
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Krajcevski, Pavel. “Improved Encoding for Compressed Textures.” 2016. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:8be0e9e0-06aa-427c-a00c-dc8ec11171ae.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Krajcevski, Pavel. “Improved Encoding for Compressed Textures.” 2016. Web. 18 Jan 2021.
Vancouver:
Krajcevski P. Improved Encoding for Compressed Textures. [Internet] [Thesis]. University of North Carolina; 2016. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:8be0e9e0-06aa-427c-a00c-dc8ec11171ae.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Krajcevski P. Improved Encoding for Compressed Textures. [Thesis]. University of North Carolina; 2016. Available from: https://cdr.lib.unc.edu/record/uuid:8be0e9e0-06aa-427c-a00c-dc8ec11171ae
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
19.
Cochran, Robert.
Symbolic Verification of Remote Client Behavior in Distributed Systems.
Degree: Computer Science, 2016, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:cece40cb-c644-4c69-8afd-8e86c31017bd
► A malicious client in a distributed system can undermine the integrity of the larger distributed application in a number of different ways. For example, a…
(more)
▼ A malicious client in a distributed system can undermine the integrity of the larger distributed application in a number of different ways. For example, a server with a vulnerability may be compromised directly by a modified client. If a client is authoritative for state in the larger distributed application, a malicious client may transmit an altered version of this state throughout the distributed application. A player in a networked game might cheat by modifying the client executable or the user of a network service might craft a sequence of messages that exploit a vulnerability in a server application. We present symbolic client verification, a technique for detecting whether network traffic from a remote client could have been generated by sanctioned software. Our method is based on constraint solving and symbolic execution and uses the client source code as a model for expected behavior. By identifying possible execution paths a remote client may have followed to generate a particular sequence of network traffic, we enable a precise verification technique that has the benefits of requiring little to no modification to the client application and is server agnostic; the only required inputs to the algorithm are the observed network traffic and the client source code. We demonstrate a parallel symbolic client verification algorithm that vastly reduces verification costs for our case study applications XPilot and Tetrinet.
Advisors/Committee Members: Cochran, Robert, Reiter, Michael, Monrose, Fabian, Cadar, Cristian, Manocha, Dinesh, Jha, Somesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Cochran, R. (2016). Symbolic Verification of Remote Client Behavior in Distributed Systems. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:cece40cb-c644-4c69-8afd-8e86c31017bd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Cochran, Robert. “Symbolic Verification of Remote Client Behavior in Distributed Systems.” 2016. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:cece40cb-c644-4c69-8afd-8e86c31017bd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Cochran, Robert. “Symbolic Verification of Remote Client Behavior in Distributed Systems.” 2016. Web. 18 Jan 2021.
Vancouver:
Cochran R. Symbolic Verification of Remote Client Behavior in Distributed Systems. [Internet] [Thesis]. University of North Carolina; 2016. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:cece40cb-c644-4c69-8afd-8e86c31017bd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Cochran R. Symbolic Verification of Remote Client Behavior in Distributed Systems. [Thesis]. University of North Carolina; 2016. Available from: https://cdr.lib.unc.edu/record/uuid:cece40cb-c644-4c69-8afd-8e86c31017bd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
20.
Park, Chonhyon.
High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization.
Degree: Computer Science, 2016, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:e8c00599-184e-4a90-afb3-802044542a15
► Motion planning is an important problem in robotics, computer-aided design, and simulated environments. Recently, robots with a high number of controllable joints are increasingly used…
(more)
▼ Motion planning is an important problem in robotics, computer-aided design, and simulated environments. Recently, robots with a high number of controllable joints are increasingly used for different applications, including in dynamic environments with humans and other moving objects. In this thesis, we address three main challenges related to motion planning algorithms for high-DOF robots in dynamic environments: 1) how to compute a feasible and constrained motion trajectory in dynamic environments; 2) how to improve the performance of realtime computations for high-DOF robots; 3) how to model the uncertainty in the environment representation and the motion of the obstacles. We present a novel optimization-based algorithm for motion planning in dynamic environments. We model various constraints corresponding to smoothness, as well as kinematics and dynamics bounds, as a cost function, and perform stochastic trajectory optimization to compute feasible high-dimensional trajectories. In order to handle arbitrary dynamic obstacles, we use a replanning framework that interleaves planning with execution. We also parallelize our approach on multiple CPU or GPU cores to improve the performance and perform realtime computations. In order to deal with the uncertainty of dynamic environments, we present an efficient probabilistic collision detection algorithm that takes into account noisy sensor data. We predict the future obstacle motion as Gaussian distributions, and compute the bounded collision probability between a high-DOF robot and obstacles. We highlight the performance of our algorithms in simulated environments as well as with a 7-DOF Fetch arm.
Advisors/Committee Members: Park, Chonhyon, Manocha, Dinesh, Lin, Ming, Alterovitz, Ron, Frahm, Jan-Michael, O'O'Sullivan, Carol.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Park, C. (2016). High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:e8c00599-184e-4a90-afb3-802044542a15
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Park, Chonhyon. “High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization.” 2016. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:e8c00599-184e-4a90-afb3-802044542a15.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Park, Chonhyon. “High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization.” 2016. Web. 18 Jan 2021.
Vancouver:
Park C. High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization. [Internet] [Thesis]. University of North Carolina; 2016. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:e8c00599-184e-4a90-afb3-802044542a15.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Park C. High-DOF Motion Planning in Dynamic Environments using Trajectory Optimization. [Thesis]. University of North Carolina; 2016. Available from: https://cdr.lib.unc.edu/record/uuid:e8c00599-184e-4a90-afb3-802044542a15
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
21.
Cochran, Robert.
Symbolic Verification of Remote Client Behavior in Distributed Systems.
Degree: Computer Science, 2016, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:cf4c9320-985d-4abc-8816-c4758d4dbd1c
► A malicious client in a distributed system can undermine the integrity of the larger distributed application in a number of different ways. For example, a…
(more)
▼ A malicious client in a distributed system can undermine the integrity of the larger distributed application in a number of different ways. For example, a server with a vulnerability may be compromised directly by a modified client. If a client is authoritative for state in the larger distributed application, a malicious client may transmit an altered version of this state throughout the distributed application. A player in a networked game might cheat by modifying the client executable or the user of a network service might craft a sequence of messages that exploit a vulnerability in a server application. We present symbolic client verification, a technique for detecting whether network traffic from a remote client could have been generated by sanctioned software. Our method is based on constraint solving and symbolic execution and uses the client source code as a model for expected behavior. By identifying possible execution paths a remote client may have followed to generate a particular sequence of network traffic, we enable a precise verification technique that has the benefits of requiring little to no modification to the client application and is server agnostic; the only required inputs to the algorithm are the observed network traffic and the client source code. We demonstrate a parallel symbolic client verification algorithm that vastly reduces verification costs for our case study applications XPilot and Tetrinet.
Advisors/Committee Members: Cochran, Robert, Reiter, Michael, Monrose, Fabian, Cadar, Cristian, Manocha, Dinesh, Jha, Somesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
Record Details
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Share »
Record Details
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« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Cochran, R. (2016). Symbolic Verification of Remote Client Behavior in Distributed Systems. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:cf4c9320-985d-4abc-8816-c4758d4dbd1c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Cochran, Robert. “Symbolic Verification of Remote Client Behavior in Distributed Systems.” 2016. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:cf4c9320-985d-4abc-8816-c4758d4dbd1c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Cochran, Robert. “Symbolic Verification of Remote Client Behavior in Distributed Systems.” 2016. Web. 18 Jan 2021.
Vancouver:
Cochran R. Symbolic Verification of Remote Client Behavior in Distributed Systems. [Internet] [Thesis]. University of North Carolina; 2016. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:cf4c9320-985d-4abc-8816-c4758d4dbd1c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Cochran R. Symbolic Verification of Remote Client Behavior in Distributed Systems. [Thesis]. University of North Carolina; 2016. Available from: https://cdr.lib.unc.edu/record/uuid:cf4c9320-985d-4abc-8816-c4758d4dbd1c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
22.
Best, Andrew.
Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints.
Degree: Computer Science, 2018, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:e15d846f-804f-45d7-aa00-ca3cbd868f11
► Man-made entities and humans rely on movement as an essential form of interaction with the world. Whether it is an autonomous vehicle navigating crowded roadways…
(more)
▼ Man-made entities and humans rely on movement as an essential form of interaction with the world. Whether it is an autonomous vehicle navigating crowded roadways or a simulated pedestrian traversing a virtual world, each entity must compute safe, effective paths to achieve their goals. In addition, these entities, termed agents, are subject to unique physical and behavioral limitations within their environment. For example, vehicles have a finite physical turning radius and must obey behavioral constraints such as traffic signals and rules of the road. Effective motion planning algorithms for diverse agents must account for these physics-based and behavior constraints.
In this dissertation, we present novel motion planning algorithms that account for constraints which physically limit the agent and impose behavioral limitations on the virtual agents. We describe representational approaches to capture specific physical constraints on the various agents and propose abstractions to model behavior constraints affecting them. We then describe algorithms to plan motions for agents who are subject to the modeled constraints.
First, we describe a biomechanically accurate elliptical representation for virtual pedestrians; we also describe human-like movement constraints corresponding to shoulder-turning and side-stepping in dense environments. We detail a novel motion planning algorithm extending velocity obstacles to generate collisionfree paths for hundreds of elliptical agents at interactive rates. Next, we describe an algorithm to encode dynamics and traffic-like behavior constraints for autonomous vehicles in urban and highway environments. We describe a motion planning algorithm to generate safe, high-speed avoidance maneuvers using a novel optimization function and modified control obstacle formulation, and we also present a simulation framework to evaluate driving strategies. Next, we present an approach to incorporate high-level reasoning to model the motions and behaviors of virtual agents in terms of verbal interactions with other agents or avatars. Our approach leverages natural-language interaction to reduce uncertainty and generate effective plans. Finally, we describe an application of our techniques to simulate pedestrian behaviors for gathering simulated data about loading, unloading, and evacuating an aircraft.
Advisors/Committee Members: Best, Andrew, Manocha, Dinesh, Alterovitz, Ron, Lin, Ming, Barber, Daniel, Mayer-Patel, Ketan.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Best, A. (2018). Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:e15d846f-804f-45d7-aa00-ca3cbd868f11
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Best, Andrew. “Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints.” 2018. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:e15d846f-804f-45d7-aa00-ca3cbd868f11.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Best, Andrew. “Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints.” 2018. Web. 18 Jan 2021.
Vancouver:
Best A. Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints. [Internet] [Thesis]. University of North Carolina; 2018. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:e15d846f-804f-45d7-aa00-ca3cbd868f11.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Best A. Interactive Motion Planning for Multi-agent Systems with Physics-based and Behavior Constraints. [Thesis]. University of North Carolina; 2018. Available from: https://cdr.lib.unc.edu/record/uuid:e15d846f-804f-45d7-aa00-ca3cbd868f11
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
23.
Wilkie, David.
SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:b5246c1e-0528-404c-a925-6f2ce95a6cdd
► Few phenomena are more ubiquitous than traffic, and few are more significant economically, socially, or environmentally. The vast, world-spanning road network enables the daily commutes…
(more)
▼ Few phenomena are more ubiquitous than traffic, and few are more significant economically, socially, or environmentally. The vast, world-spanning road network enables the daily commutes of billions of people and makes us mobile in a way our ancestors would have envied. And yet, few systems perform so poorly so often. Gridlock and traffic jams cost 2.9 billion gallons of wasted fuel and costs over 121 billion dollars every year in the U.S. alone. One promising approach to improving the reliability and efficiency of traffic systems is to fully incorporate computational techniques into the system, transforming the traffic systems of today into cyber-physical systems. However, creating a truly cyber-physical traffic system will require overcoming many substantial challenges. The state of traffic at any given time is unknown for the majority of the road network. The dynamics of traffic are complex, noisy, and dependent on drivers' decisions. The domain of the system, the real-world road network, has no suitable representation for high-detail simulation. And there is no known solution for improving the efficiency and reliability of the system. In this dissertation, I propose techniques that combine simulation and data to solve these challenges and enable large-scale traffic state estimation, simulation, and route planning. First, to create and represent road networks, I propose an efficient method for enhancing noisy GIS road maps to create geometrically and topologically consistent 3D models for high-detail, real-time traffic simulation, interactive visualization, traffic state estimation, and vehicle routing. The resulting representation provides important road features for traffic simulations, including ramps, highways, overpasses, merge zones, and intersections with arbitrary states. Second, to estimate and communicate traffic conditions, I propose a fast technique to reconstruct traffic flows from in-road sensor measurements or user-specified control points for interactive 3D visualization and communication. My algorithm estimates the full state of the traffic flow from sparse sensor measurements using a statistical inference method and a continuum traffic model. This estimated state then drives an agent-based traffic simulator to produce a 3D animation of traffic that statistically matches the sensed traffic conditions. Third, to improve real-world traffic system efficiency, I propose a novel approach that takes advantage of mobile devices, such as cellular phones or embedded systems in cars, to form an interactive, participatory network of vehicles that plan their travel routes based on the current, sensed traffic conditions and the future, projected traffic conditions, which are estimated from the routes planned by all the participants. The premise of this approach is that a route, or plan, for a vehicle is also a prediction of where the car will travel. If routes are planned for a sizable percentage of the vehicles using the road network, an estimate for the overall traffic pattern is attainable. If fewer cars are…
Advisors/Committee Members: Wilkie, David, Lin, Ming, Manocha, Dinesh, Alterovitz, Ron, Lastra, Anselmo, Sewall, Jason.
Subjects/Keywords: Computer science; Transportation – Planning; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wilkie, D. (2015). SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:b5246c1e-0528-404c-a925-6f2ce95a6cdd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wilkie, David. “SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:b5246c1e-0528-404c-a925-6f2ce95a6cdd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wilkie, David. “SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC.” 2015. Web. 18 Jan 2021.
Vancouver:
Wilkie D. SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:b5246c1e-0528-404c-a925-6f2ce95a6cdd.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wilkie D. SIMULATING, RECONSTRUCTING, AND ROUTING METROPOLITAN-SCALE TRAFFIC. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:b5246c1e-0528-404c-a925-6f2ce95a6cdd
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
24.
Golas, Abhinav.
Modeling of Complex Large-Scale Flow Phenomena.
Degree: Computer Science, 2015, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:e0c6bd26-b449-4333-b5a3-172821a0a6b7
► Flows at large scales are capable of unmatched complexity. At large spatial scales, they can exhibit phenomena like waves, tornadoes, and a screaming concert audience;…
(more)
▼ Flows at large scales are capable of unmatched complexity. At large spatial scales, they can exhibit phenomena like waves, tornadoes, and a screaming concert audience; at high densities, they can create shockwaves, and can cause stampedes. Though strides have been made in simulating flows like fluids and crowds, extending these algorithms with scale poses challenges in ensuring accuracy while maintaining computational efficiency. In this dissertation, I present novel techniques to simulate large-scale flows using coupled Eulerian-Lagrangian models that employ a combination of discretized grids and dynamic particle-based representations. I demonstrate how such models can efficiently simulate flows at large-scales, while maintaining fine-scale features. In fluid simulation, a long-standing problem has been the simulation of large-scale scenes without compromising fine-scale features. Though approximate multi-scale models exist, accurate simulation of large-scale fluid flow has remained constrained by memory and computational limits of current generation PCs. I propose a hybrid domain-decomposition model that, by coupling Lagrangian vortex-based methods with Eulerian velocity-based methods, reduces memory requirements and improves performance on parallel architectures. The resulting technique can efficiently simulate scenes significantly larger than those possible with either model alone. The motion of crowds is another class of flows that exhibits novel complexities with increasing scale. Navigation of crowds in virtual worlds is traditionally guided by a static global planner, combined with dynamic local collision avoidance. However, such models cannot capture long-range crowd interactions commonly observed in pedestrians. This discrepancy can cause sharp changes in agent trajectories, and sub-optimal navigation. I present a technique to add long-range vision to virtual crowds by performing collision avoidance at multiple spatial and temporal scales for both Eulerian and Lagrangian crowd navigation models, and a novel technique to blend both approaches in order to obtain collision-free velocities efficiently. The resulting simulated crowds show better correspondence with real-world pedestrians in both qualitative and quantitative metrics, while adding a minimal computational overhead. Another aspect of real-world crowds missing from virtual agents is their behavior at high densities. Crowds at such scales can often exhibit chaotic behavior commonly known as emph{crowd turbulence}; this phenomenon has the potential to cause mishaps leading to loss of life. I propose modeling inter-personal stress in dense crowds using an Eulerian model, coupled with a physically-based Lagrangian agent-based model to simulate crowd turbulence. I demonstrate how such a hybrid model can create virtual crowds whose trajectories show visual and quantifiable similarities to turbulent crowds in the real world. The techniques proposed in this thesis demonstrate that hybrid Eulerian-Lagrangian modeling presents a versatile approach for modeling…
Advisors/Committee Members: Golas, Abhinav, Lin, Ming, Manocha, Dinesh, Lastra, Anselmo, Sewall, Jason, Adalsteinsson, David.
Subjects/Keywords: Computer science; Mechanics, Applied – Mathematics; College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Golas, A. (2015). Modeling of Complex Large-Scale Flow Phenomena. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:e0c6bd26-b449-4333-b5a3-172821a0a6b7
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Golas, Abhinav. “Modeling of Complex Large-Scale Flow Phenomena.” 2015. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:e0c6bd26-b449-4333-b5a3-172821a0a6b7.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Golas, Abhinav. “Modeling of Complex Large-Scale Flow Phenomena.” 2015. Web. 18 Jan 2021.
Vancouver:
Golas A. Modeling of Complex Large-Scale Flow Phenomena. [Internet] [Thesis]. University of North Carolina; 2015. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:e0c6bd26-b449-4333-b5a3-172821a0a6b7.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Golas A. Modeling of Complex Large-Scale Flow Phenomena. [Thesis]. University of North Carolina; 2015. Available from: https://cdr.lib.unc.edu/record/uuid:e0c6bd26-b449-4333-b5a3-172821a0a6b7
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
25.
YANG, SHAN.
NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS.
Degree: Computer Science, 2018, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:7841341b-857a-4e7d-9872-05d23b63e56d
► Material property has great importance in surgical simulation and virtual reality. The mechanical properties of the human soft tissue are critical to characterize the tissue…
(more)
▼ Material property has great importance in surgical simulation and virtual reality. The mechanical properties of the human soft tissue are critical to characterize the tissue deformation of each patient. Studies have shown that the tissue stiffness described by the tissue properties may indicate abnormal pathological process. The (recovered) elasticity parameters can assist surgeons to perform better pre-op surgical planning and enable medical robots to carry out personalized surgical procedures. Traditional elasticity parameters estimation methods rely largely on known external forces measured by special devices and strain field estimated by landmarks on the deformable bodies. Or they are limited to mechanical property estimation for quasi-static deformation. For virtual reality applications such as virtual try-on, garment material capturing is of equal significance as the geometry reconstruction.
In this thesis, I present novel approaches for automatically estimating the material properties of soft bodies from images or from a video capturing the motion of the deformable body. I use a coupled simulation-optimization-identification framework to deform one soft body at its original, non-deformed state to match the deformed geometry of the same object in its deformed state. The optimal set of material parameters is thereby determined by minimizing the error metric function. This method can simultaneously recover the elasticity parameters of multiple regions of soft bodies using Finite Element Method-based simulation (of either linear or nonlinear materials undergoing large deformation) and particle-swarm optimization methods. I demonstrate the effectiveness of this approach on real-time interaction with virtual organs in patient-specific surgical simulation, using parameters acquired from low-resolution medical images. With the recovered elasticity parameters and the age of the prostate cancer patients as features, I build a cancer grading and staging classifier. The classifier achieves up to 91% for predicting cancer T-Stage and 88% for predicting Gleason score. To recover the mechanical properties of soft bodies from a video, I propose a method which couples statistical graphical model with FEM simulation. Using this method, I can recover the material properties of a soft ball from a high-speed camera video that captures the motion of the
ball.
Furthermore, I extend the material recovery framework to fabric material identification. I propose a novel method for garment material extraction from a single-view image and a learning based cloth material recovery method from a video recording the motion of the cloth. Most recent garment capturing techniques rely on acquiring multiple views of clothing, which may not always be readily available, especially in the case of pre-existing photographs from the web. As an alternative, I propose a method that can compute a 3D model of a human body and its outfit from a single photograph with little human interaction. My proposed learning-based cloth material type…
Advisors/Committee Members: YANG, SHAN, Lin, Ming, Berg, Tamara, Bregler, Chris, Manocha, Dinesh, Jojic, Vladimir, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
YANG, S. (2018). NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:7841341b-857a-4e7d-9872-05d23b63e56d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
YANG, SHAN. “NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS.” 2018. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:7841341b-857a-4e7d-9872-05d23b63e56d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
YANG, SHAN. “NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS.” 2018. Web. 18 Jan 2021.
Vancouver:
YANG S. NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS. [Internet] [Thesis]. University of North Carolina; 2018. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:7841341b-857a-4e7d-9872-05d23b63e56d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
YANG S. NON-RIGID BODY MECHANICAL PROPERTY RECOVERY FROM IMAGES AND VIDEOS. [Thesis]. University of North Carolina; 2018. Available from: https://cdr.lib.unc.edu/record/uuid:7841341b-857a-4e7d-9872-05d23b63e56d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
26.
Wang, Ke.
Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery.
Degree: Computer Science, 2018, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:a342d2a8-51a5-44c4-b4b5-8d9a1ac68700
► Recent years have witnessed the rapid growth of commercial satellite imagery. Compared with other imaging products, such as aerial or streetview imagery, modern satellite images…
(more)
▼ Recent years have witnessed the rapid growth of commercial satellite imagery. Compared with other imaging products, such as aerial or streetview imagery, modern satellite images are captured at high resolution and with multiple spectral bands, thus provide unique viewing angles, global coverage, and frequent updates of the Earth surfaces. With automated processing and intelligent analysis algorithms, satellite images can enable global-scale 3D modeling applications.
This dissertation explores computer vision algorithms to reconstruct 3D models from satellite images at different levels: geometric, semantic, and parametric reconstructions. However, reconstructing satellite imagery is particularly challenging for the following reasons: 1) Satellite images typically contain an enormous amount of raw pixels. Efficient algorithms are needed to minimize the substantial computational burden. 2) The ground sampling distances of satellite images are comparatively low. Visual entities, such as buildings, appear visually small and cluttered, thus posing difficulties for 3D modeling. 3) Satellite images usually have complex camera models and inaccurate vendor-provided camera calibrations. Rational polynomial coefficients (RPC) camera models, although widely used, need to be appropriately handled to ensure high-quality reconstructions.
To obtain geometric reconstructions efficiently, we propose an edge-aware interpolation-based algorithm to obtain 3D point clouds from satellite image pairs. Initial 2D pixel matches are first established and triangulated to compensate the RPC calibration errors. Noisy dense correspondences can then be estimated by interpolating the inlier matches in an edge-aware manner. After refining the correspondence map with a fast bilateral solver, we can obtain dense 3D point clouds via triangulation.
Pixel-wise semantic classification results for satellite images are usually noisy due to the negligence of spatial neighborhood information. Thus, we propose to aggregate multiple corresponding observations of the same 3D point to obtain high-quality semantic models. Instead of just leveraging geometric reconstructions to provide such correspondences, we formulate geometric modeling and semantic reasoning in a joint Markov Random Field (MRF) model. Our experiments show that both tasks can benefit from the joint inference.
Finally, we propose a novel deep learning based approach to perform single-view parametric reconstructions from satellite imagery. By parametrizing buildings as 3D cuboids, our method simultaneously localizes building instances visible in the image and estimates their corresponding cuboid models. Aerial LiDAR and vectorized GIS maps are utilized as supervision. Our network upsamples CNN features to detect small but cluttered building instances. In addition, we estimate building contours through a separate fully convolutional network to avoid overlapping building cuboids.
Advisors/Committee Members: Wang, Ke, Frahm, Jan-Michael, Dunn, Enrique, Berg, Alexander, Manocha, Dinesh, Niethammer, Marc, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wang, K. (2018). Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:a342d2a8-51a5-44c4-b4b5-8d9a1ac68700
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Ke. “Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery.” 2018. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:a342d2a8-51a5-44c4-b4b5-8d9a1ac68700.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Ke. “Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery.” 2018. Web. 18 Jan 2021.
Vancouver:
Wang K. Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery. [Internet] [Thesis]. University of North Carolina; 2018. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:a342d2a8-51a5-44c4-b4b5-8d9a1ac68700.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang K. Towards Efficient 3D Reconstructions from High-Resolution Satellite Imagery. [Thesis]. University of North Carolina; 2018. Available from: https://cdr.lib.unc.edu/record/uuid:a342d2a8-51a5-44c4-b4b5-8d9a1ac68700
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
27.
Zhang, Liangjun.
Efficient motion planning using generalized penetration depth computation.
Degree: Computer Science, 2009, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:0e9fe64d-2ec6-4d8e-a71c-dbb34d622c2d
► Motion planning is a fundamental problem in robotics and also arises in other applications including virtual prototyping, navigation, animation and computational structural biology. It has…
(more)
▼ Motion planning is a fundamental problem in robotics and also arises in other applications including virtual prototyping, navigation, animation and computational structural biology. It has been extensively studied for more than three decades, though most practical algorithms are based on randomized sampling. In this dissertation, we address two main issues that arise with respect to these algorithms: (1) there are no good practical approaches to check for path non-existence even for low degree-of-freedom (DOF) robots; (2) the performance of sampling-based planners can degrade if the free space of a robot has narrow passages. In order to develop effective algorithms to deal with these problems, we use the concept of penetration depth (PD) computation. By quantifying the extent of the intersection between overlapping models (e.g. a robot and an obstacle), PD can provide a distance measure for the configuration space obstacle (C-obstacle). We extend the prior notion of translational PD to generalized PD, which takes into account translational as well as rotational motion to separate two overlapping models. Moreover, we formulate generalized PD computation based on appropriate model-dependent metrics and present two algorithms based on convex decomposition and local optimization. We highlight the efficiency and robustness of our PD algorithms on many complex 3D models. Based on generalized PD computation, we present the first set of practical algorithms for low DOF complete motion planning. Moreover, we use generalized PD computation to develop a retraction-based planner to effectively generate samples in narrow passages for rigid robots. The effectiveness of the resulting planner is shown by alpha puzzle benchmark and part disassembly benchmarks in virtual prototyping.
Advisors/Committee Members: Zhang, Liangjun, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, L. (2009). Efficient motion planning using generalized penetration depth computation. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:0e9fe64d-2ec6-4d8e-a71c-dbb34d622c2d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhang, Liangjun. “Efficient motion planning using generalized penetration depth computation.” 2009. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:0e9fe64d-2ec6-4d8e-a71c-dbb34d622c2d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhang, Liangjun. “Efficient motion planning using generalized penetration depth computation.” 2009. Web. 18 Jan 2021.
Vancouver:
Zhang L. Efficient motion planning using generalized penetration depth computation. [Internet] [Thesis]. University of North Carolina; 2009. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:0e9fe64d-2ec6-4d8e-a71c-dbb34d622c2d.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhang L. Efficient motion planning using generalized penetration depth computation. [Thesis]. University of North Carolina; 2009. Available from: https://cdr.lib.unc.edu/record/uuid:0e9fe64d-2ec6-4d8e-a71c-dbb34d622c2d
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
28.
Sud, Avneesh.
Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron.
Degree: Computer Science, 2006, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:cbf0feeb-d5f6-452f-b6c7-2da3d26a7357
► The Voronoi diagram is a fundamental geometric data structure and has been well studied in computational geometry and related areas. A Voronoi diagram defined using…
(more)
▼ The Voronoi diagram is a fundamental geometric data structure and has been well studied in computational geometry and related areas. A Voronoi diagram defined using the Euclidean distance metric is also closely related to the Blum medial axis, a well known skeletal representation. Voronoi diagrams and medial axes have been shown useful for many 3D computations and operations, including proximity queries, motion planning, mesh generation, finite element analysis, and shape analysis. However, their application to complex 3D polyhedral and deformable models has been limited. This is due to the difficulty of computing exact Voronoi diagrams in an efficient and reliable manner. In this dissertation, we bridge this gap by presenting efficient algorithms to compute discrete Voronoi diagrams and simplified medial axes of 3D polyhedral models with geometric and topological guarantees. We apply these algorithms to complex 3D models and use them to perform interactive proximity queries, motion planning and skeletal computations. We present three new results. First, we describe an algorithm to compute 3D distance fields of geometric models by using a linear factorization of Euclidean distance vectors. This formulation maps directly to the linearly interpolating graphics rasterization hardware and enables us to compute distance fields of complex 3D models at interactive rates. We also use clamping and culling algorithms based on properties of Voronoi diagrams to accelerate this computation. We introduce surface distance maps, which are a compact distance vector field representation based on a mesh parameterization of triangulated two-manifolds, and use them to perform proximity computations. Our second main result is an adaptive sampling algorithm to compute an approximate Voronoi diagram that is homotopy equivalent to the exact Voronoi diagram and preserves topological features. We use this algorithm to compute a homotopy-preserving simplified medial axis of complex 3D models. Our third result is a unified approach to perform different proximity queries among multiple deformable models using second order discrete Voronoi diagrams. We introduce a new query called N-body distance query and show that different proximity queries, including collision detection, separation distance and penetration depth can be performed based on Nbody distance query. We compute the second order discrete Voronoi diagram using graphics hardware and use distance bounds to overcome the sampling errors and perform conservative computations. We have applied these queries to various deformable simulations and observed up to an order of magnitude improvement over prior algorithms.
Advisors/Committee Members: Sud, Avneesh, Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA (6th Edition):
Sud, A. (2006). Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:cbf0feeb-d5f6-452f-b6c7-2da3d26a7357
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sud, Avneesh. “Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron.” 2006. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:cbf0feeb-d5f6-452f-b6c7-2da3d26a7357.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sud, Avneesh. “Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron.” 2006. Web. 18 Jan 2021.
Vancouver:
Sud A. Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron. [Internet] [Thesis]. University of North Carolina; 2006. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:cbf0feeb-d5f6-452f-b6c7-2da3d26a7357.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sud A. Efficient computation of discrete Voronoi diagram and homotopy-preserving simplified medial axis of a 3d polyhedron. [Thesis]. University of North Carolina; 2006. Available from: https://cdr.lib.unc.edu/record/uuid:cbf0feeb-d5f6-452f-b6c7-2da3d26a7357
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
29.
Merrell, Paul C.
Model synthesis.
Degree: Computer Science, 2009, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:52c766f2-2635-4032-aa60-c6a37aee9b0c
► Three-dimensional models are extensively used in nearly all types of computer graphics applications. The demand for 3D models is large and growing. However, despite extensive…
(more)
▼ Three-dimensional models are extensively used in nearly all types of computer graphics applications. The demand for 3D models is large and growing. However, despite extensive work in modeling for over four decades, model generation remains a labor-intensive and difficult process even with the best available tools. We present a new procedural modeling technique called model synthesis that is designed to generate many classes of objects. Model synthesis is inspired by developments in texture synthesis. Model synthesis is designed to automatically generate a large model that resembles a small example model provided by the user. Every small part of the generated model is identical to a small part of the example model. By altering the example model, a wide variety of objects can be produced. We present several different model synthesis algorithms and analyze their strengths and weaknesses. Discrete model synthesis generates models built out of small building blocks or model pieces. Continuous model synthesis generates models on set of parallel planes. We also show how to incorporate several additional user-defined constraints to control the large-scale structure of the model, to control how the objects are distributed, and to generate symmetric models. The generality of the approach will be demonstrated by showing many models produced using each approach including cities, landscapes, spaceships, and castles. The models contain hundreds of thousands of model pieces and are generated in only a few minutes.
Advisors/Committee Members: Merrell, Paul C., Manocha, Dinesh.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
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APA ·
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MLA ·
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APA (6th Edition):
Merrell, P. C. (2009). Model synthesis. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:52c766f2-2635-4032-aa60-c6a37aee9b0c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Merrell, Paul C. “Model synthesis.” 2009. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:52c766f2-2635-4032-aa60-c6a37aee9b0c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Merrell, Paul C. “Model synthesis.” 2009. Web. 18 Jan 2021.
Vancouver:
Merrell PC. Model synthesis. [Internet] [Thesis]. University of North Carolina; 2009. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:52c766f2-2635-4032-aa60-c6a37aee9b0c.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Merrell PC. Model synthesis. [Thesis]. University of North Carolina; 2009. Available from: https://cdr.lib.unc.edu/record/uuid:52c766f2-2635-4032-aa60-c6a37aee9b0c
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of North Carolina
30.
Lloyd, D. Brandon.
Logarithmic perspective shadow maps.
Degree: Computer Science, 2007, University of North Carolina
URL: https://cdr.lib.unc.edu/record/uuid:393be0fb-3729-43af-963f-ac64cf2d3da3
► The shadow map algorithm is a popular approach for generating shadows for real-time applications. Shadow maps are flexible and easy to implement, but they are…
(more)
▼ The shadow map algorithm is a popular approach for generating shadows for real-time applications. Shadow maps are flexible and easy to implement, but they are prone to aliasing artifacts. To reduce aliasing artifacts we introduce logarithmic perspective shadow maps (LogPSMs). LogPSMs are based on a novel shadow map parameterization that consists of a perspective projection and a logarithmic transformation. They can be used for both point and directional light sources to produce hard shadows. To establish the benefits of LogPSMs, we perform an in-depth analysis of shadow map aliasing error and the error characteristics of existing algorithms. Using this analysis we compute a parameterization that produces near-optimal perspective aliasing error. This parameterization has high arithmetical complexity which makes it less practical than existing methods. We show, however, that over all light positions, the simpler LogPSM parameterization produces the same maximum error as the near-optimal parameterization. We also show that compared with competing algorithms, LogPSMs produce significantly less aliasing error. Equivalently, for the same error as competing algorithms, LogPSMs require significantly less storage and bandwidth. We demonstrate difference in shadow quality achieved with LogPSMs on several models of varying complexity. LogPSMs are rendered using logarithmic rasterization. We show how current GPU architectures can be modified incrementally to perform logarithmic rasterization at current GPU fill rates. Specifically, we modify the rasterizer to support rendering to a nonuniform grid with the same watertight rasterization properties as current rasterizers. We also describe a novel depth compression scheme to handle the nonlinear primitives produced by logarithmic rasterization. Our proposed architecture enhancements align with current trends of decreasing cost for on-chip computation relative to off-chip bandwidth and storage. For only a modest increase in computation, logarithmic rasterization can greatly reduce shadow map bandwidth and storage costs.
Advisors/Committee Members: Lloyd, D. Brandon, Manocha, Dinesh, University of North Carolina at Chapel Hill.
Subjects/Keywords: College of Arts and Sciences; Department of Computer Science
Record Details
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Share »
Record Details
Similar Records
Cite
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lloyd, D. B. (2007). Logarithmic perspective shadow maps. (Thesis). University of North Carolina. Retrieved from https://cdr.lib.unc.edu/record/uuid:393be0fb-3729-43af-963f-ac64cf2d3da3
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lloyd, D Brandon. “Logarithmic perspective shadow maps.” 2007. Thesis, University of North Carolina. Accessed January 18, 2021.
https://cdr.lib.unc.edu/record/uuid:393be0fb-3729-43af-963f-ac64cf2d3da3.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lloyd, D Brandon. “Logarithmic perspective shadow maps.” 2007. Web. 18 Jan 2021.
Vancouver:
Lloyd DB. Logarithmic perspective shadow maps. [Internet] [Thesis]. University of North Carolina; 2007. [cited 2021 Jan 18].
Available from: https://cdr.lib.unc.edu/record/uuid:393be0fb-3729-43af-963f-ac64cf2d3da3.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lloyd DB. Logarithmic perspective shadow maps. [Thesis]. University of North Carolina; 2007. Available from: https://cdr.lib.unc.edu/record/uuid:393be0fb-3729-43af-963f-ac64cf2d3da3
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
. 
Open Access Theses and Dissertations