+publisher:"University of Southern California" +contributor:("Sukhatme, Gaurav S.")

University of Southern California

1. Gupta, Megha. Intelligent robotic manipulation of cluttered environments.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/521349/rec/3563

► Robotic household assistants of the future will need to understand their environment in real-time with high accuracy. There are two problems that make this challenging… (more)

▼ Robotic household assistants of the future will need to understand their environment in real-time with high accuracy. There are two problems that make this challenging for robots. First, human environments are typically cluttered, containing a lot of objects of all kinds, shapes and sizes, in close proximity. This introduces errors in the robot’s perception and manipulation. Second, human environments are highly varied. Improving a robot’s perceptual abilities can tackle these challenge only partially. A robot’s ability to manipulate its environment can help in enabling and overcoming the limits of perception. ❧ We test this idea of manipulation-aided perception in the context of sorting and searching in cluttered, bounded, and partially observable environments. The inherent uncertainty in the world state forces the robot to adopt an observe-plan-act strategy where perception, planning, and execution are interleaved. Since execution of an action may result in revealing information about the world that was unknown hitherto, a new plan needs to be generated as a consequence of the robots actions. Since manipulation is typically expensive on a robot, our goal is to reduce the number of object manipulations required to complete the desired task. ❧ This thesis presents planning algorithms for a robot’s intelligent physical interaction with its cluttered environment. The focus is on using simple manipulation primitives to declutter the world and making task completion easier and faster using the environment’s local structure or context. For object sorting, we present a robust pipeline that combines manipulation-aided perception and grasping to achieve more reliable and accurate sorting results. In the context of environment exploration, we present an adaptive look-ahead algorithm for exploration by prehensile and non-prehensile manipulation of the objects in the environment. This algorithm is then applied to manipulation-based object search in real world. Finally, we add contextual structure to the world in the form of object-object co-occurrence relations and present an algorithm that uses context to guide the object search. ❧ We evaluate the performance and applicability of our planners through extensive simulations and real-world experiments on the PR2 robot. Our results show that purposeful manipulation of clutter to aid perception becomes increasingly useful (and essential) as the clutter in the environment increases, and that intelligent manipulation of a cluttered environment improves the efficiency of robotic tasks. Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Schaal, Stefan (Committee Member), Krishnamachari, Bhaskar (Committee Member).

Subjects/Keywords: robotic manipulation; planning algorithms; personal robots; sensor-based manipulation

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APA (6^th Edition):

Gupta, M. (2014). Intelligent robotic manipulation of cluttered environments. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/521349/rec/3563

Chicago Manual of Style (16^th Edition):

Gupta, Megha. “Intelligent robotic manipulation of cluttered environments.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/521349/rec/3563.

MLA Handbook (7^th Edition):

Gupta, Megha. “Intelligent robotic manipulation of cluttered environments.” 2014. Web. 26 Feb 2021.

Vancouver:

Gupta M. Intelligent robotic manipulation of cluttered environments. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/521349/rec/3563.

Council of Science Editors:

Gupta M. Intelligent robotic manipulation of cluttered environments. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/521349/rec/3563

University of Southern California

2. Kalakrishnan, Mrinal. Learning objective functions for autonomous motion generation.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/369146/rec/3787

► Planning and optimization methods have been widely applied to the problem of trajectory generation for autonomous robotics. The performance of such methods, however, is critically… (more)

▼ Planning and optimization methods have been widely applied to the problem of trajectory generation for autonomous robotics. The performance of such methods, however, is critically dependent on the choice of objective function being optimized, and is non‐trivial to design. On the other end of the spectrum, efforts on learning autonomous behavior from user‐provided demonstrations have largely been focused on reproducing behavior similar in appearance to the provided demonstrations. An alternative approach, known as Inverse Reinforcement Learning (IRL), is to learn an objective function that the demonstrations are assumed to be optimal under. With the help of a planner or trajectory optimizer, such an approach allows the system to synthesize novel behavior in situations that were not experienced in the demonstrations. ❧ We present novel algorithms for IRL that have successfully been applied in two real‐world, competitive robotics settings: (1) In the domain of rough terrain quadruped locomotion, we present an algorithm that learns an objective function for foothold selection based on ”terrain templates”. The learner automatically generates and selects the appropriate features which form the objective function, which reduces the need for feature engineering while attaining a high level of generalization. (2) For the domain of autonomous manipulation, we present a probabilistic model of optimal trajectories, which results in new algorithms for inverse reinforcement learning and trajectory optimization in high‐dimensional settings. We apply this method to two problems in robotic manipulation: redundancy resolution in inverse kinematics, and trajectory optimization for grasping and manipulation. Both methods have proven themselves as part of larger integrated systems in competitive settings against other teams, where testing was conducted by an independent test team in situations that were not seen during training. Advisors/Committee Members: Schaal, Stefan (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Valero-Cuevas, Francisco (Committee Member).

Subjects/Keywords: robotics; machine learning; motion planning; trajectory optimization; inverse reinforcement learning; reinforcement learning; locomotion; manipulation

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APA (6^th Edition):

Kalakrishnan, M. (2014). Learning objective functions for autonomous motion generation. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/369146/rec/3787

Chicago Manual of Style (16^th Edition):

Kalakrishnan, Mrinal. “Learning objective functions for autonomous motion generation.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/369146/rec/3787.

MLA Handbook (7^th Edition):

Kalakrishnan, Mrinal. “Learning objective functions for autonomous motion generation.” 2014. Web. 26 Feb 2021.

Vancouver:

Kalakrishnan M. Learning objective functions for autonomous motion generation. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/369146/rec/3787.

Council of Science Editors:

Kalakrishnan M. Learning objective functions for autonomous motion generation. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/369146/rec/3787

University of Southern California

3. Koenig, Nathan. Robot life-long task learning from human demonstrations: a Bayesian approach.

Degree: PhD, Computer Science (Robotics and Automation), 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222240/rec/5611

► Programming a robot to act intelligently is a challenging endeavor that is beyond the skill level of most people. Trained roboticists generally program robots for… (more)

▼ Programming a robot to act intelligently is a challenging endeavor that is beyond the skill level of most people. Trained roboticists generally program robots for a single purpose. Enabling robots to be programmed by non-experts and to perform multiple tasks are both open challenges in robotics. The contributions of this work include a framework that allows a robot to learn tasks from demonstrations over the course of its functional lifetime, a task representation that uses Bayesian decision networks, and a method to transfer knowledge between similar tasks. The demonstration framework allows non-experts to demonstrate tasks to the robot in an intuitive manner. ❧ In this work, tasks are complex time-extended decision processes that make use of a set of predefined basis behaviors for actuator control. Demonstrations from an instructor provide the necessary information for the robot to learn a control policy. An instructor guides the robot through a demonstration using a graphical interface that displays information from the robot and provides an intuitive action-object pairing mechanism to issue commands to the robot. ❧ Each task is represented by an influence diagram, a generalization of Bayesian networks. The networks are human readable, compact, and have a simple refinement process. They are not subject to an exponential growth in states or in branches, and can be combined hierarchically, allowing for complex task models. Data from task demonstrations are used to learn the structure and utility functions of an influence diagram. A score-based learning algorithm is used to search through potential networks in order to find an optimal structure. ❧ Both the means by which demonstrations are provided to the robot and the learned tasks are validated. Different communication modalities and environmental factors are analyzed in a set of user studies. The studies feature both engineer and non-engineer users instructing the Willow Garage PR2 on four tasks: Tower's of Hanoi, box sorting, cooking risotto, and table setting. The results validate that the approach enables the robot to learn complex tasks from a variety of teachers, refining those tasks during on-line performance, successfully completing the tasks in different environments, and transferring knowledge from one task to another. Advisors/Committee Members: Mataric, Maja J. (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Jain, Rahul (Committee Member).

Subjects/Keywords: robotics; life-long learning; influence diagrams; bayesian networks; teaching; learning from demonstration

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Koenig, N. (2013). Robot life-long task learning from human demonstrations: a Bayesian approach. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222240/rec/5611

Chicago Manual of Style (16^th Edition):

Koenig, Nathan. “Robot life-long task learning from human demonstrations: a Bayesian approach.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222240/rec/5611.

MLA Handbook (7^th Edition):

Koenig, Nathan. “Robot life-long task learning from human demonstrations: a Bayesian approach.” 2013. Web. 26 Feb 2021.

Vancouver:

Koenig N. Robot life-long task learning from human demonstrations: a Bayesian approach. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222240/rec/5611.

Council of Science Editors:

Koenig N. Robot life-long task learning from human demonstrations: a Bayesian approach. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222240/rec/5611

University of Southern California

4. Choudhuri, Chiranjib. Joint communication and sensing over state dependent channels.

Degree: PhD, Electrical Engineering, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/220838/rec/3694

► The fundamental trade-off between communication rate and estimation error in sensing the channel state at the decoder is investigated for a discrete memoryless channel with… (more)

▼ The fundamental trade-off between communication rate and estimation error in sensing the channel state at the decoder is investigated for a discrete memoryless channel with discrete memoryless action dependent state when the state information is available either partially or fully at the encoder. We first investigate the capacity a relay channel with finite memory, where the action independent fixed channel state information is assumed to be known at both the encoder and decoder and then went on to investigate the problem of determining the trade-off between capacity and distortion for the channel with states known only at the encoder. ❧ The relay channel with finite memory is modeled with channels with inter-symbol interference (ISI) and additive colored Gaussian noise. The channel state or channel impulse responses are assumed to be known at both the encoders and decoder. Prior results are used to show that the capacity of this channel can be computed by examining the circular degraded relay channel in the limit of infinite block length. The thesis provides single letter expressions for the achievable rates with decode-and-forward (DF) and compress-and-forward (CF) processing employed at the relay. Additionally, the cut-set bound for the relay channel is generalized for the ISI/colored Gaussian noise scenario. All results hinge on showing the optimality of the decomposition of the relay channel with ISI/colored Gaussian noise into an equivalent collection of coupled parallel, scalar, memoryless relay channels. The region of optimality of the DF and CF achievable rates is also discussed. The resulting rates are illustrated through the computation of numerical examples. ❧ The problem of state communication over a discrete memoryless channel with discrete memoryless state when the state information is available strictly causally at the encoder is then studied. It is shown that block Markov encoding, in which the encoder communicates a description of the state sequence in the previous block by incorporating side information about the state sequence at the decoder, yields the minimum state estimation error. When the same channel is used to send additional independent information at the expense of a higher channel state estimation error, the optimal tradeoff between the rate of the independent information and the state estimation error is characterized via the capacity–distortion function. It is shown that any optimal tradeoff pair can be achieved via rate-splitting. These coding theorems are then extended optimally to the case of causal channel state information at the encoder using the Shannon strategy. ❧ For non-causal channel state knowledge at the encoder, information-theoretic lower and upper bounds (based respectively on ideas from hybrid-coding and rate–distortion theory) are derived on the capacity– distortion function. Some examples are provided, for which the capacity–distortion functions are characterized by showing that the two bounds match. These coding theorems are then extended to the case of source… Advisors/Committee Members: Mitra, Urbashi (Committee Chair), Caire, Giuseppe (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: communication; estimation; wireless communication; state estimation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Choudhuri, C. (2013). Joint communication and sensing over state dependent channels. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/220838/rec/3694

Chicago Manual of Style (16^th Edition):

Choudhuri, Chiranjib. “Joint communication and sensing over state dependent channels.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/220838/rec/3694.

MLA Handbook (7^th Edition):

Choudhuri, Chiranjib. “Joint communication and sensing over state dependent channels.” 2013. Web. 26 Feb 2021.

Vancouver:

Choudhuri C. Joint communication and sensing over state dependent channels. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/220838/rec/3694.

Council of Science Editors:

Choudhuri C. Joint communication and sensing over state dependent channels. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/220838/rec/3694

University of Southern California

5. Fasola, Juan Pablo. Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/440892/rec/5940

► The growing population of aging adults is increasing the demand for healthcare services worldwide. Socially assistive robotics (SAR) and service robotics have the potential to… (more)

▼ The growing population of aging adults is increasing the demand for healthcare services worldwide. Socially assistive robotics (SAR) and service robotics have the potential to aid in addressing the needs of the growing elderly population by promoting health benefits, independent living, and improved quality of life. For such robots to become ubiquitous in real‐world human environments, they will need to interact with and learn from non‐expert users in a manner that is both natural and practical for the users. In particular, such robots will need to be capable of understanding natural language instructions in order to learn new tasks and receive guidance and feedback on task execution. ❧ Research into SAR and service robotics‐based solutions for non‐expert users, and in particular older adults, that spans varied assistive tasks generally falls within one of two distinct areas: 1) robot‐guided interaction, and 2) user‐guided interaction. This dissertation contributes to both of these research areas. ❧ To address robot‐guided interaction, this dissertation presents the design methodology, implementation and evaluation details of a novel SAR approach to motivate and engage elderly users in simple physical exercise. The approach incorporates insights from psychology research into intrinsic motivation and contributes five clear design principles for SAR‐based therapeutic interventions. To evaluate the approach and its effectiveness in gaining user acceptance and motivating physical exercise, it was implemented as an integrated system and three user studies were conducted with older adults, to investigate: 1) the effect of praise and relational discourse in the system towards increasing user motivation; 2) the role of user autonomy and choice within the interaction; and 3) the effect of embodiment in the system by comparing user evaluations of similar physically and virtually embodied SAR exercise coaches in addition to evaluating the overall SAR system. ❧ To address user‐guided interactions, specifically with non‐expert users through the use of natural language instructions, this dissertation presents a novel methodology that allows service robots to interpret and follow spatial language instructions, with and without user‐specified natural language constraints and/or unvoiced pragmatic constraints. This work contributes a general computational framework for the representation of dynamic spatial relations, with both local and global properties. The methodology also contributes a probabilistic approach in the inference of instruction semantics; a general approach for interpreting object pick‐and‐place tasks; and a novel probabilistic algorithm for the automatic extraction of contextually and semantically valid instruction sequences from unconstrained spatial language discourse, including those containing anaphoric reference expressions. The spatial language interpretation methodology was evaluated in simulation, on two different physical robot platforms, and in a user study conducted with older adults for validation with… Advisors/Committee Members: Mataric, Maja J. (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Hagedorn, Aaron (Committee Member).

Subjects/Keywords: human‐robot interaction; socially assistive robotics; spatial language understanding; natural language processing; intrinsic motivation; exercise therapy; older adults

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APA (6^th Edition):

Fasola, J. P. (2014). Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/440892/rec/5940

Chicago Manual of Style (16^th Edition):

Fasola, Juan Pablo. “Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/440892/rec/5940.

MLA Handbook (7^th Edition):

Fasola, Juan Pablo. “Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse.” 2014. Web. 26 Feb 2021.

Vancouver:

Fasola JP. Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/440892/rec/5940.

Council of Science Editors:

Fasola JP. Socially assistive and service robotics for older adults: methodologies for motivating exercise and following spatial language instructions in discourse. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/440892/rec/5940

University of Southern California

6. Gong, Boqing. Kernel methods for unsupervised domain adaptation.

Degree: PhD, Computer Science, 2015, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/604358/rec/3708

► In many applications (computer vision, natural language processing, speech recognition, etc.), the curse of domain mismatch arises when the test data (of a target domain)… (more)

▼ In many applications (computer vision, natural language processing, speech recognition, etc.), the curse of domain mismatch arises when the test data (of a target domain) and the training data (of some source domain(s)) come from different distributions. Thus, developing techniques for domain adaptation, i.e., generalizing models from the sources to the target, has been a pressing need. When the learner has access to only unlabeled data from the target domain (and labeled data from the source domain), the problem is called unsupervised domain adaptation. Advances in domain adaptation can significantly increase our capability to deploy autonomous and intelligent systems in challenging environments where uncertainty prevails. ❧ This thesis work provides a comprehensive set of techniques with multiple levels of focus on unsupervised domain adaptation, including learning domain‐invariant feature representations in order to eliminate the discrepancy between the source domain and the target domain, manipulating data instances to match the distributions of two domains, quantizing the ""adaptabilities"" of different source domains given a particular target domain, and discovering latent domains from heterogeneous data so the individual domains can be better and more efficiently modeled. We demonstrate the effectiveness of the developed methods on well‐benchmarked datasets and tasks (visual object recognition, sentiment analysis, and cross‐view human activity recognition). ❧ In terms of domain adaptation algorithms, this thesis develops two complementary approaches using kernel methods, one to infer domain‐invariant geodesic flow kernels (GFKs) and the other to directly match the underlying distributions of two domains. GFK models data by subspaces and interpolates an infinite number of phantom domains between the source domain and the target domain. We then use the ""kernel trick"" to average out domain‐specific idiosyncrasies and arrive at a domain‐invariant kernel. Built upon GFK, we propose an approach to identifying the most adaptable data instances of the source domain, named as landmarks, to the target domain. Due to that the landmarks are more similar to the target domain in the sense of their underlying distributions, adapting from the landmarks gives rise to better performance on the target than adapting from the original source domain. ❧ This thesis also contributes to other aspects of domain adaptation. We make some preliminary efforts on answering the open question of how to evaluate the ""adaptability"" of a source domain to the target domain. This results in a rank‐of‐domains (ROD) metric, which exploits both geometrical and statistical discrepancies between two domains. Besides, this thesis raises the concern about how to define or represent a domain with real data. While by a domain we refer to the underlying distribution of the observed data, the distribution is often unknown. A standard practice has been equating datasets with domains. However, our studies show that this is not necessarily the best for the… Advisors/Committee Members: Sha, Fei (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Narayanan, Shrikanth S. (Committee Member).

Subjects/Keywords: kernel methods; domain adaptation; geodesic flow kernel; landmarks; rank of domains; latent domains; sequential determinantal point process

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APA (6^th Edition):

Gong, B. (2015). Kernel methods for unsupervised domain adaptation. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/604358/rec/3708

Chicago Manual of Style (16^th Edition):

Gong, Boqing. “Kernel methods for unsupervised domain adaptation.” 2015. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/604358/rec/3708.

MLA Handbook (7^th Edition):

Gong, Boqing. “Kernel methods for unsupervised domain adaptation.” 2015. Web. 26 Feb 2021.

Vancouver:

Gong B. Kernel methods for unsupervised domain adaptation. [Internet] [Doctoral dissertation]. University of Southern California; 2015. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/604358/rec/3708.

Council of Science Editors:

Gong B. Kernel methods for unsupervised domain adaptation. [Doctoral Dissertation]. University of Southern California; 2015. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/604358/rec/3708

University of Southern California

7. de Menezes Pereira, Arvind Antonio. Risk-aware path planning for autonomous underwater vehicles.

Degree: PhD, Computer Science, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/351180/rec/5603

► Path planning is the process of generating an optimal sequence of waypoints from a start configuration to a desired goal configuration under constraints (e.g., avoiding… (more)

▼ Path planning is the process of generating an optimal sequence of waypoints from a start configuration to a desired goal configuration under constraints (e.g., avoiding obstacles, respecting time/energy budgets). In this thesis, we study the problem of risk-aware planning. Specifically, we design, develop, and experimentally validate optimal paths for Autonomous Underwater Vehicles (AUVs) in the open ocean in the presence of navigational hazards such as ships and other obstacles. A novel aspect of this work is the introduction of ocean current predictions to optimize planning in such settings. This is challenging because current predictions are typ- ically available at non-uniform spatial resolution, noisy, and time-delayed. We designed three risk-aware planners that reason probabilistically about the uncer- tainty in ocean currents predictions. The minimum expected risk planner ensures that the AUV always reaches the goal, while minimizing risk along the way, Risk- aware Markov Decision Process-based planning uses stationary models over a short horizon, and trades off between goal-directed behavior and reducing risk. This is susceptible to finding sub-optimal policies due to stationarity. The non-stationary, risk-aware MDP makes use of variability in the currents where possible to overcome high-risk sections of paths on the way to the goal. In addition to these planners, we develop a taxonomy for risk-aware planning in dynamic settings. Another key contribution is learning the uncertainty in currents to improve planning. Results from extensive simulations clearly show that learning uncertainty helps significantly improve performance of risk-aware planners in uncertain currents, allowing AUVs to be operated in more challenging scenarios than was previously possible. Finally, the planners described in this dissertation have been field tested at unprecedented levels to validate their practical utility (∼2000 hours of testing at sea). Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Schaal, Stefan (Committee Member), Caron, David A. (Committee Member).

Subjects/Keywords: artificial intelligence; path planning; autonomous underwater vehicles; gliders

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APA (6^th Edition):

de Menezes Pereira, A. A. (2013). Risk-aware path planning for autonomous underwater vehicles. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/351180/rec/5603

Chicago Manual of Style (16^th Edition):

de Menezes Pereira, Arvind Antonio. “Risk-aware path planning for autonomous underwater vehicles.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/351180/rec/5603.

MLA Handbook (7^th Edition):

de Menezes Pereira, Arvind Antonio. “Risk-aware path planning for autonomous underwater vehicles.” 2013. Web. 26 Feb 2021.

Vancouver:

de Menezes Pereira AA. Risk-aware path planning for autonomous underwater vehicles. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/351180/rec/5603.

Council of Science Editors:

de Menezes Pereira AA. Risk-aware path planning for autonomous underwater vehicles. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/351180/rec/5603

University of Southern California

8. Binney, Jonathan Douglas. Informative path planning for environmental monitoring.

Degree: PhD, Computer Science, 2012, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/104369/rec/3496

► Mobile aquatic, aerial, and terrestrial robots open up rich opportunities for environmental monitoring. Sensors mounted on a robot can be moved to take measurements in… (more)

Subjects/Keywords: robotics; path planning; environmental monitoring

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APA (6^th Edition):

Binney, J. D. (2012). Informative path planning for environmental monitoring. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/104369/rec/3496

Chicago Manual of Style (16^th Edition):

Binney, Jonathan Douglas. “Informative path planning for environmental monitoring.” 2012. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/104369/rec/3496.

MLA Handbook (7^th Edition):

Binney, Jonathan Douglas. “Informative path planning for environmental monitoring.” 2012. Web. 26 Feb 2021.

Vancouver:

Binney JD. Informative path planning for environmental monitoring. [Internet] [Doctoral dissertation]. University of Southern California; 2012. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/104369/rec/3496.

Council of Science Editors:

Binney JD. Informative path planning for environmental monitoring. [Doctoral Dissertation]. University of Southern California; 2012. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/104369/rec/3496

University of Southern California

9. Das, Jnaneshwar. Data-driven robotic sampling for marine ecosystem monitoring.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/409762/rec/1778

► The marine environment is in a perpetual state of flux due to ocean currents. As a result, phenomena such as plankton blooms are constantly advected,… (more)

▼ The marine environment is in a perpetual state of flux due to ocean currents. As a result, phenomena such as plankton blooms are constantly advected, making their observation challenging. Traditionally, measurements from remote‐sensing satellites, ships, piers, and moorings have helped scientists study such phenomena. However, a sound understanding of bloom ecology and dynamics requires persistent sampling at spatio‐temporal scales infeasible with existing methods. Advances in robotic sampling using autonomous underwater vehicles (AUVs) have opened up the arena for adaptive sampling at unprecedented scales, augmenting other methods of observation. ❧ This thesis presents a novel data‐driven robotic sampling methodology for marine ecosystem monitoring, focusing on the observation of plankton blooms. The problem is addressed at multiple spatio‐temporal scales to detect, track, and sample blooms with the goal of acquisition of physical water samples for ex‐situ analysis of plankton abundance. This is essential for the understanding of plankton ecology and community structure since sensors onboard AUVs are incapable of measuring precise biological data in realtime, necessitating lab analysis of water samples. ❧ Starting at the macro scale (kilometers/days), this work demonstrates how remote sensing imagery and periodic measurements of surface currents facilitate detection and trajectory projection of plankton blooms to plan AUV deployments. Once deployed, the AUV needs to survey within the context of the advecting bloom. The thesis presents the design of Lagrangian surveys wherein a bloom is tagged with a GPS‐tracked drifter, and surveys are designed and executed in the frame of reference of the advecting bloom. Results from a field experiment where a 1km x 1km patch of water was successfully tracked by an AUV over multiple days demonstrate the efficacy of this approach. Next, during such Lagrangian surveys, the AUV is required to carry out adaptive water sample acquisition for ex‐situ analysis. The thesis describes a principled online sampling strategy that uses probabilistic regression models trained on previously collected data to predict abundance of desired plankton from realtime measurements of physical and chemical properties by the AUV’s onboard sensor suite. Extensive simulations carried out by mining historical data, and a one‐day field trial targeting a toxinogenic plankton demonstrate the impact of the approach, in effect ""closing the loop"" on a a significant science problem. Finally, the thesis describes an Oceanographic Decision Support System (ODSS), a web‐based tool developed for situational awareness and data visualization during robotic sampling experiments of the kind presented in this work. Extensive use during a month‐long field campaign with multiple platforms and users demonstrate the importance of support tools in marine ecosystem monitoring. ❧ Through extensive experimental results, the thesis demonstrates robotic sampling for marine ecosystem monitoring at an unprecedented spatio‐temporal… Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Schaal, Stefan (Committee Member), Caron, David A. (Committee Member).

Subjects/Keywords: robotics; robotic sampling; field robotics; marine robotics; underwater robots; autonomous underwater vehicles; AUVs; machine learning; software systems; adaptive sampling; experiment design; environmental monitoring

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APA (6^th Edition):

Das, J. (2014). Data-driven robotic sampling for marine ecosystem monitoring. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/409762/rec/1778

Chicago Manual of Style (16^th Edition):

Das, Jnaneshwar. “Data-driven robotic sampling for marine ecosystem monitoring.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/409762/rec/1778.

MLA Handbook (7^th Edition):

Das, Jnaneshwar. “Data-driven robotic sampling for marine ecosystem monitoring.” 2014. Web. 26 Feb 2021.

Vancouver:

Das J. Data-driven robotic sampling for marine ecosystem monitoring. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/409762/rec/1778.

Council of Science Editors:

Das J. Data-driven robotic sampling for marine ecosystem monitoring. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/409762/rec/1778

University of Southern California

10. Reinebold, James L., III. Evaluating mobile phones as opportunistic on-body sensors.

Degree: MS, Computer Science, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/668898/rec/2524

► Mobile phones are an inexpensive sensing solution that can provide insight into the personal environment of the person using the device. However, the challenge for… (more)

Subjects/Keywords: mobile phones; opportunistic sensing; movement detection; friend detection; on-body sensors

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APA (6^th Edition):

Reinebold, James L., I. (2011). Evaluating mobile phones as opportunistic on-body sensors. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/668898/rec/2524

Chicago Manual of Style (16^th Edition):

Reinebold, James L., III. “Evaluating mobile phones as opportunistic on-body sensors.” 2011. Masters Thesis, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/668898/rec/2524.

MLA Handbook (7^th Edition):

Reinebold, James L., III. “Evaluating mobile phones as opportunistic on-body sensors.” 2011. Web. 26 Feb 2021.

Vancouver:

Reinebold, James L. I. Evaluating mobile phones as opportunistic on-body sensors. [Internet] [Masters thesis]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/668898/rec/2524.

Council of Science Editors:

Reinebold, James L. I. Evaluating mobile phones as opportunistic on-body sensors. [Masters Thesis]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/668898/rec/2524

University of Southern California

11. Ramachandran, Gokul. A biologically inspired role-based team strategy for pursuit-evasion in robots.

Degree: MS, Computer Science (Robotics and Automation), 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/653087/rec/53

► This thesis presents a robust, scalable and general Java applet-based simulator for pursuit-evasion problems. With this tool, experiments can be conducted by simulating multi-player pursuit-evasion… (more)

Subjects/Keywords: chasing; rvasion; pursuit; robotics; simulator; team; pursuit evasion; pursuit-evasion; team strategy; agents; agent based; agent-based; Java; iRobot Create; JavaCV; Bluetooth; firewire camera

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APA (6^th Edition):

Ramachandran, G. (2011). A biologically inspired role-based team strategy for pursuit-evasion in robots. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/653087/rec/53

Chicago Manual of Style (16^th Edition):

Ramachandran, Gokul. “A biologically inspired role-based team strategy for pursuit-evasion in robots.” 2011. Masters Thesis, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/653087/rec/53.

MLA Handbook (7^th Edition):

Ramachandran, Gokul. “A biologically inspired role-based team strategy for pursuit-evasion in robots.” 2011. Web. 26 Feb 2021.

Vancouver:

Ramachandran G. A biologically inspired role-based team strategy for pursuit-evasion in robots. [Internet] [Masters thesis]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/653087/rec/53.

Council of Science Editors:

Ramachandran G. A biologically inspired role-based team strategy for pursuit-evasion in robots. [Masters Thesis]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/653087/rec/53

University of Southern California

12. Pastor, Peter. Data-driven autonomous manipulation.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/406876/rec/1773

► The problem of an aging society is real and will affect everyone. There will be too few young people that can ensure adequate living conditions… (more)

▼ The problem of an aging society is real and will affect everyone. There will be too few young people that can ensure adequate living conditions for the elderly. Personal robots have the potential to assist in day‐to‐day tasks whenever there are too few humans to cope with societal needs. However, for personal robots to become useful they need to be able to skillfully manipulate objects in their environment. Unfortunately, the problem of autonomous manipulation is very complex and progress towards creating autonomous behaviors seems to have reached a plateau. ❧ In this thesis, we will present a data‐driven approach to movement generation. We argue that movement generation (motor output) and perceptual processing (sensor input) are inseparably intertwined and that the ability to predict sensor information is essential for skillful manipulation. Movement generation without sensor expectations defaults to open‐loop execution which is prone to failure in dynamic and unstructured environments. However, predicting sensor information for an increasing number of sensor modalities including force/torque and tactile feedback through physics based modelling is challenging given the variety of objects, the diversity of possible manipulation behaviors, and the uncertainty in the real world. Instead, our approach leverages a key insight: Movement generation can dictate expected sensor feedback. Similar manipulation movements will give rise to sensory events that are similar to previous ones. Thus, stereotypical movements facilitate to associate and accumulate sensor information from past trials and use these sensor experiences to predict sensor feedback in future trials. ❧ We will call such movements augmented with associated sensor information Associative Skill Memories (ASMs). We will present a coherent data‐driven framework for manipulation that implements this paradigm. First, we will introduce a modular movement representation suitable to encode movements along with associated sensor experiences. Second, we will show how stereotypical movements can be learned from demonstrations and refined using trial‐and‐error learning. Third, we will show how ASMs can be used to monitor task progress, to realize contact reactive manipulation, and to purposefully choose subsequent movements. Finally, we will present a method that can learn forward models for these stereotypical movements. Advisors/Committee Members: Schaal, Stefan (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Schweighofer, Nicolas (Committee Member).

Subjects/Keywords: data‐driven; autonomous; robotic manipulation; movement primitives; motor primitives; associative memory; associative skill memories

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APA (6^th Edition):

Pastor, P. (2014). Data-driven autonomous manipulation. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/406876/rec/1773

Chicago Manual of Style (16^th Edition):

Pastor, Peter. “Data-driven autonomous manipulation.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/406876/rec/1773.

MLA Handbook (7^th Edition):

Pastor, Peter. “Data-driven autonomous manipulation.” 2014. Web. 26 Feb 2021.

Vancouver:

Pastor P. Data-driven autonomous manipulation. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/406876/rec/1773.

Council of Science Editors:

Pastor P. Data-driven autonomous manipulation. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/406876/rec/1773

University of Southern California

13. Wang, Yi. Towards energy efficient mobile sensing.

Degree: PhD, Electrical Engineering, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/445526/rec/7537

► Mobile device based urban sensing, participatory sensing, and user activity recognition can provide rich contextual information for mobile applications such as social networking and location… (more)

▼ Mobile device based urban sensing, participatory sensing, and user activity recognition can provide rich contextual information for mobile applications such as social networking and location based services. However, as the sensors on mobile devices consume significant amount of energy, the major bottleneck that restricts the continuous functioning of these mobile applications is the limited battery capacity on mobile devices.; In this thesis, we first present a novel design framework for an Energy Efficient Mobile Sensing System (EEMSS). EEMSS uses hierarchical sensor management strategy to recognize user states as well as to detect state transitions. By powering only a minimum set of sensors and managing sensors hierarchically, EEMSS significantly improves device battery life. We present the design, implementation, and evaluation of EEMSS that automatically recognizes a set of users' daily activities in real time using sensors on an off-the-shelf high-end smart phone. Evaluation of EEMSS with 10 users over one week shows that our approach increases the device battery life by more than 75% while maintaining both high accuracy and low latency in identifying transitions between end-user activities.; We then propose a computationally efficient algorithm to obtain the optimal sensor sampling policy under the assumption that the user state transition is Markovian. This Markov-optimal policy minimizes user state estimation error while satisfying a given energy consumption budget. The Markov-optimal policy is compared to uniform periodic sensing and performance improvement is obtained on both simulated and real user state traces, with approximately 20% average gain on empirically collected user data that pertains to user motion, inter-user contact status, and network connectivity.; Finally, we formulate the user state sensing problem as the intermittent sampling of a semi-Markov process, a model that provides more general and flexible capturing of realistic data. We propose (a) a semi-Markovian state estimation mechanism that selects the most likely user state while observations are missing, and (b) a semi-Markov optimal sensing policy which minimizes the expected state estimation error while maintaining a given energy budget. Their performance is shown to significantly outperform Markovian algorithms on simulated two-state processes and real user state traces. In addition, we propose a novel client-server based energy efficient mobile sensing system architecture that automatically learns user dynamics and computes user-specific optimal sensing policy for mobile devices. A system prototype aiming to recognize basic human activity is implemented on Nokia N95 smartphones and desktop computers. We demonstrate the performance benchmark of the semi-Markov optimal policy through a set of experiments, and show that it improves the estimation accuracy by 27.8% and 48.6% over Markov-optimal policy and uniform sampling, respectively. Advisors/Committee Members: Krishnamachari, Bhaskar (Committee Chair), Annavaram, Murali (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: constrained stochastic optimization; energy efficiency; mobile sensing; state estimation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wang, Y. (2011). Towards energy efficient mobile sensing. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/445526/rec/7537

Chicago Manual of Style (16^th Edition):

Wang, Yi. “Towards energy efficient mobile sensing.” 2011. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/445526/rec/7537.

MLA Handbook (7^th Edition):

Wang, Yi. “Towards energy efficient mobile sensing.” 2011. Web. 26 Feb 2021.

Vancouver:

Wang Y. Towards energy efficient mobile sensing. [Internet] [Doctoral dissertation]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/445526/rec/7537.

Council of Science Editors:

Wang Y. Towards energy efficient mobile sensing. [Doctoral Dissertation]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/445526/rec/7537

University of Southern California

14. Yerramalli, Srinivas. Communication and cooperation in underwater acoustic networks.

Degree: PhD, Electrical Engineering, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222584/rec/1468

► In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve… (more)

▼ In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve the achievable data rate on a point to point link using better physical layer techniques and then study sensor cooperation which improves the throughput and reliability in an underwater network. ❧ Robust point-to-point communications in underwater networks has become increasingly critical in several military and civilian applications related to underwater communications. We present several physical layer signaling and detection techniques tailored to the underwater channel model to improve the reliability of data detection. First, a simplified underwater channel model in which the time scale distortion on each path is assumed to be the same (single scale channel model in contrast to a more general multi scale model). A novel technique, which exploits the nature of OFDM signaling and the time scale distortion, called Partial FFT Demodulation is derived. It is observed that this new technique has some unique interference suppression properties and performs better than traditional equalizers in several scenarios of interest. Next, we consider the multi scale model for the underwater channel and assume that single scale processing is performed at the receiver. We then derive optimized front end pre-processing techniques to reduce the interference caused during single scale processing of signals transmitted on a multi-scale channel. We then propose an improvised channel estimation technique using dictionary optimization methods for compressive sensing and show that significant performance gains can be obtained using this technique. ❧ In the next part of this thesis, we consider the problem of sensor node cooperation among rational nodes whose objective is to improve their individual data rates. We first consider the problem of transmitter cooperation in a multiple access channel and investigate the stability of the grand coalition of transmitters using tools from cooperative game theory and show that the grand coalition in both the asymptotic regimes of high and low SNR. Towards studying the problem of receiver cooperation for a broadcast channel, we propose a game theoretic model for the broadcast channel and then derive a game theoretic duality between the multiple access and the broadcast channel and show that how the equilibria of the broadcast channel are related to the multiple access channel and vice versa. Advisors/Committee Members: Mitra, Urbashi (Committee Chair), Jain, Rahul (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: underwater communications; wideband communications; OFDM; Doppler; time scale; partial FFT; estimator analysis; resampling; channel estimation; cooperation; game theory; wireless networks; partition form games; interference modeling; multiple access channels; broadcast channels; duality; Generalized Nash Equilibrium Problems

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Yerramalli, S. (2013). Communication and cooperation in underwater acoustic networks. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222584/rec/1468

Chicago Manual of Style (16^th Edition):

Yerramalli, Srinivas. “Communication and cooperation in underwater acoustic networks.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222584/rec/1468.

MLA Handbook (7^th Edition):

Yerramalli, Srinivas. “Communication and cooperation in underwater acoustic networks.” 2013. Web. 26 Feb 2021.

Vancouver:

Yerramalli S. Communication and cooperation in underwater acoustic networks. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222584/rec/1468.

Council of Science Editors:

Yerramalli S. Communication and cooperation in underwater acoustic networks. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/222584/rec/1468

University of Southern California

15. Subbaraya, Supreeth. Development of Lagrangian drifter for ocean monitoring and marine applications.

Degree: MS, Electrical Engineering, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/382246/rec/1950

► This thesis describes the design and development of a Lagrangian Drifter for ocean monitoring applications. The system is developed to move with the currents at… (more)

Subjects/Keywords: drifter; ocean monitoring; drogue; marine system

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APA (6^th Edition):

Subbaraya, S. (2014). Development of Lagrangian drifter for ocean monitoring and marine applications. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/382246/rec/1950

Chicago Manual of Style (16^th Edition):

Subbaraya, Supreeth. “Development of Lagrangian drifter for ocean monitoring and marine applications.” 2014. Masters Thesis, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/382246/rec/1950.

MLA Handbook (7^th Edition):

Subbaraya, Supreeth. “Development of Lagrangian drifter for ocean monitoring and marine applications.” 2014. Web. 26 Feb 2021.

Vancouver:

Subbaraya S. Development of Lagrangian drifter for ocean monitoring and marine applications. [Internet] [Masters thesis]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/382246/rec/1950.

Council of Science Editors:

Subbaraya S. Development of Lagrangian drifter for ocean monitoring and marine applications. [Masters Thesis]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/382246/rec/1950

University of Southern California

16. Khodaei, Ali. Combining textual Web search with spatial, temporal and social aspects of the Web.

Degree: PhD, Computer Science, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/338255/rec/1458

► Over the last few years, Web has changed significantly. Emergence of Web 2.0 has enabled people to interact with web documents in new ways not… (more)

Subjects/Keywords: search; information retrieval; ranking; indexing; social; spatial; temporal; textual; Web; social network; inverted index; contextual search; personalized search; spatiotemporal; Web 2.0

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Khodaei, A. (2013). Combining textual Web search with spatial, temporal and social aspects of the Web. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/338255/rec/1458

Chicago Manual of Style (16^th Edition):

Khodaei, Ali. “Combining textual Web search with spatial, temporal and social aspects of the Web.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/338255/rec/1458.

MLA Handbook (7^th Edition):

Khodaei, Ali. “Combining textual Web search with spatial, temporal and social aspects of the Web.” 2013. Web. 26 Feb 2021.

Vancouver:

Khodaei A. Combining textual Web search with spatial, temporal and social aspects of the Web. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/338255/rec/1458.

Council of Science Editors:

Khodaei A. Combining textual Web search with spatial, temporal and social aspects of the Web. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/338255/rec/1458

University of Southern California

17. Kazemi, Leyla. Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing.

Degree: PhD, Computer Science, 2012, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/119471/rec/2336

► With the ubiquity of mobile devices, spatial crowdsourcing is emerging as a new platform, enabling spatial tasks (i.e., tasks related to a location) assigned to… (more)

Subjects/Keywords: crowdsourcing; spatial; privacy; trust

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kazemi, L. (2012). Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/119471/rec/2336

Chicago Manual of Style (16^th Edition):

Kazemi, Leyla. “Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing.” 2012. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/119471/rec/2336.

MLA Handbook (7^th Edition):

Kazemi, Leyla. “Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing.” 2012. Web. 26 Feb 2021.

Vancouver:

Kazemi L. Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing. [Internet] [Doctoral dissertation]. University of Southern California; 2012. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/119471/rec/2336.

Council of Science Editors:

Kazemi L. Enabling query answering in a trustworthy privacy-aware spatial crowdsourcing. [Doctoral Dissertation]. University of Southern California; 2012. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/119471/rec/2336

University of Southern California

18. Gangwal, Vipresh. Pose estimation for in-hand objects.

Degree: MS, Electrical Engineering, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/672017/rec/5124

► Estimation of 6D pose of a known object in robot hand is traditionally done by using vision or range sensing. Such methods perform badly in… (more)

Subjects/Keywords: robotics; computer science; in-hand object; pose estimation; force torque sensors; iterative closest point; inertial parameters

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APA (6^th Edition):

Gangwal, V. (2011). Pose estimation for in-hand objects. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/672017/rec/5124

Chicago Manual of Style (16^th Edition):

Gangwal, Vipresh. “Pose estimation for in-hand objects.” 2011. Masters Thesis, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/672017/rec/5124.

MLA Handbook (7^th Edition):

Gangwal, Vipresh. “Pose estimation for in-hand objects.” 2011. Web. 26 Feb 2021.

Vancouver:

Gangwal V. Pose estimation for in-hand objects. [Internet] [Masters thesis]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/672017/rec/5124.

Council of Science Editors:

Gangwal V. Pose estimation for in-hand objects. [Masters Thesis]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/672017/rec/5124

University of Southern California

19. St. Clair, Aaron B. Coordinating social communication in human-robot task collaborations.

Degree: PhD, Computer Science (Robotics and Automation), 2015, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/632204/rec/1661

► Robots have become increasingly capable of performing a variety of tasks in real-world dynamic environments, including those involving people. Beyond competently performing the tasks required… (more)

▼ Robots have become increasingly capable of performing a variety of tasks in real-world dynamic environments, including those involving people. Beyond competently performing the tasks required of them, service robots should also be able to coordinate their actions with those of the people around them in order to minimize conflicts, provide feedback, and build rapport with human teammates in both work environments (e.g., manufacturing) and home settings. Humans coordinate their actions in various task settings through structured social interaction aimed at representational alignment and intentional feedback. In order for robots to coordinate their actions using similar modalities, they must be capable of contextualizing the actions of human partners and producing relevant natural communicative behaviors as the task progresses. This dissertation is motivated by the high-level goal of producing effective social feedback during task performance, and alleviating the burden of coordinating the team's joint activity by allowing human users to interact with robots through natural social modalities as partners rather than as operators. ❧ This dissertation develops an approach for constructing and generalizing models of role-based coordinating communication during physically-decoupled human-robot task scenarios, specifically pairwise collaborations in which a person and a robot work together to achieve a shared goal. The approach is validated in different task contexts with different user populations using objective and subjective measures of task performance and user preferences. To support role-allocative communication observed in our pilot experiments with two-person teams, the human-robot collaboration problem is formulated as a Markov decision process in which roles are represented by a set of policies capturing different action selection preferences and accounting for unequal capabilities between human and robot collaborators. A probabilistic method is used to track the user's activity over time and to recognize the role assumed by the user, communication is then planned given the expected policy of the user, the policy of the robot, and the current task state. The communication generated by the robot consists of three types of speech actions and associated co-verbal behavior: 1) self-narration of the robot's activities, 2) role allocation suggestions for the user, and 3) empathetic displays when positive and negative state changes occur. ❧ The approach was validated initially on a dynamic augmented reality herding task with a population of convenience users using objective metrics (idle time, distance traveled) as well as subjective evaluations (user preference, perceived intelligence of the robot), where a higher utilization of the robot and more equitable path distance was observed in comparison to a non-communicating robot. The generalizability of the approach to a different task setting and user population was also evaluated on a cooking task with an elderly user population. The contributions of this dissertation… Advisors/Committee Members: Mataric, Maja J. (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Ayanian, Nora (Committee Member), Hagedorn, Aaron T. (Committee Member).

Subjects/Keywords: human-robot interaction; human-machine collaboration; robotics; verbal feedback; collaboration

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

St. Clair, A. B. (2015). Coordinating social communication in human-robot task collaborations. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/632204/rec/1661

Chicago Manual of Style (16^th Edition):

St. Clair, Aaron B. “Coordinating social communication in human-robot task collaborations.” 2015. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/632204/rec/1661.

MLA Handbook (7^th Edition):

St. Clair, Aaron B. “Coordinating social communication in human-robot task collaborations.” 2015. Web. 26 Feb 2021.

Vancouver:

St. Clair AB. Coordinating social communication in human-robot task collaborations. [Internet] [Doctoral dissertation]. University of Southern California; 2015. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/632204/rec/1661.

Council of Science Editors:

St. Clair AB. Coordinating social communication in human-robot task collaborations. [Doctoral Dissertation]. University of Southern California; 2015. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/632204/rec/1661

University of Southern California

20. Vathsangam, Harshvardhan. Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/308578/rec/5792

► Healthcare is undergoing a paradigm shift from the episodic, expert-driven, curative approaches of the past towards a self-empowered, preventative model for the future. Central to… (more)

▼ Healthcare is undergoing a paradigm shift from the episodic, expert-driven, curative approaches of the past towards a self-empowered, preventative model for the future. Central to this is the treatment of chronic illnesses. This treatment will require the adoption of behavioral changes on one’s lifestyle. A particular illness is that brought about by the negative effects of physical inactivity. Regular physical activity is associated with decreased mortality, lower risk of cardiovascular disease, diabetes mellitus, colon and breast cancer. Despite this knowledge, physical activity levels are not adequate. ❧ Promoting physical activity will rely on designing appropriate intervention measures that bring about behavioral change. Central to this is the need to accurately measure and characterize physical activity in a cost-effective yet ubiquitous manner. One characterization of physical activity is the energy expended as a result of movement. In this dissertation, we aim to demonstrate how kinematic sensors in combination with statistical techniques can accurately predict energy expenditure due to physical activity. ❧ We cast the problem of determining energy expenditure in a mathematical framework and discuss various functional maps. We rely primarily on data-driven regression techniques to derive functional maps from movement to energy expenditure given a person’s morphology. We focus on common movements such as walking or running. ❧ In order to accurately estimate estimate energy expenditure, we derive a set of frequency-based features that are robust to location on the human body and orientation.We show how one can use the up-down movement of the center of mass of the human body to robustly characterize cyclic movement. Further, we demonstrate the utility of Fourier transform-based techniques to in detecting the periodicity of this movement. We also show a modification of the Discrete Fourier Transform to work in a recursive setting to efficiently calculate frequency components. ❧ We proceed to determine the most accurate technique to map movement to energy expenditure given sufficient data for a person. We present three algorithms: Least-Squares Regression (LSR), Bayesian Linear Regression (BLR) and Gaussian Process Regression (GPR). We compare prediction accuracies using different sensor streams and algorithms. A comparative study of accuracy versus inference time is also performed. This work presents contributions in the comparison of non-probabilistic, probabilistic, linear and nonlinear regression algorithms for wellness parameters. ❧ We extend this work to be able to generate maps given a minimal set of morphological descriptors such as height, weight, age etc. We present and compare a set of models including nearest neighbor models, weight-scaled models, a set of hierarchical linear models and speed-based approaches. We show how these approaches can be used to evaluate the best subset of morphological descriptors and the best individual descriptor to generate personalized maps across people. This work tackles… Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Sha, Fei (Committee Member), McNitt-Gray, Jill L. (Committee Member), Saponas, T. Scott (Committee Member).

Subjects/Keywords: accelerometer; machine learning; gyroscope; mobile phone; energy expenditure; statistical; regression; Gaussian process regression; Bayesian; Fourier transform; walking; physical activity

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APA (6^th Edition):

Vathsangam, H. (2014). Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/308578/rec/5792

Chicago Manual of Style (16^th Edition):

Vathsangam, Harshvardhan. “Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/308578/rec/5792.

MLA Handbook (7^th Edition):

Vathsangam, Harshvardhan. “Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors.” 2014. Web. 26 Feb 2021.

Vancouver:

Vathsangam H. Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/308578/rec/5792.

Council of Science Editors:

Vathsangam H. Sense and sensibility: statistical techniques for human energy expenditure estimation using kinematic sensors. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/308578/rec/5792

University of Southern California

21. Viswanathan, Manu. Mobile robot obstacle avoidance using a computational model of the locust brain.

Degree: MS, Computer Science (Robotics & Automation), 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433779/rec/4108

► The Lobula Giant Movement Detector (LGMD), a visual interneuron in the locust's brain, responds preferentially to objects approaching along collisional trajectories. The goal of the… (more)

Subjects/Keywords: mobile robotics; insect vision; collision detection; time-to-impact; obstacle avoidance; locust LGMD; probabilistic sensor model; Bayesian state estimation

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APA (6^th Edition):

Viswanathan, M. (2011). Mobile robot obstacle avoidance using a computational model of the locust brain. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433779/rec/4108

Chicago Manual of Style (16^th Edition):

Viswanathan, Manu. “Mobile robot obstacle avoidance using a computational model of the locust brain.” 2011. Masters Thesis, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433779/rec/4108.

MLA Handbook (7^th Edition):

Viswanathan, Manu. “Mobile robot obstacle avoidance using a computational model of the locust brain.” 2011. Web. 26 Feb 2021.

Vancouver:

Viswanathan M. Mobile robot obstacle avoidance using a computational model of the locust brain. [Internet] [Masters thesis]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433779/rec/4108.

Council of Science Editors:

Viswanathan M. Mobile robot obstacle avoidance using a computational model of the locust brain. [Masters Thesis]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/433779/rec/4108

University of Southern California

22. Williams, Ryan K. Interaction and topology in distributed multi-agent coordination.

Degree: PhD, Electrical Engineering, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/432814/rec/3570

► Interconnected systems have become the recent focus of intense investigation, particularly in the context of autonomous coordination, yielding fundamental advantages in adaptability, scalability, and efficiency… (more)

▼ Interconnected systems have become the recent focus of intense investigation, particularly in the context of autonomous coordination, yielding fundamental advantages in adaptability, scalability, and efficiency compared to single‐agent solutions. In this thesis, we investigate the topological assumptions that underly distributed multi‐agent coordination, i.e., those properties defining interaction between agents in a network. We focus specifically on the properties of network connectivity and graph rigidity, which exhibit strong influence on fundamental multi‐agent behaviors, e.g., joint decision‐making, cooperative estimation, formation control, and relative localization. These bases of coordination contribute to the construction of increasingly complex multi‐agent systems, and in harnessing the underlying threads of topology, there is hope in solving the future challenges of coordination in a world of robotic ubiquity. Thus, this thesis aims to strike distributed autonomy at its core, by treating assumptions which render theoretical treatments feasible, but which leave implementation relegated to the laboratory. ❧ Motivated by a case study that illustrates the topological assumptions necessary to solve the probabilistic mapping and tracking problem, we extend the state of the art in mobility control by regulating topology through preemptive mobility, discriminating link addition and deletion to shape spatial interaction under topological constraints. Adopting realistic models of proximity‐limited coordination, local controllers are constructed with discrete switching for link discrimination, and attract‐repel potential fields which yield constraint satisfying motion. Our mobility scheme acts as a full generalization of classical swarm‐like controllers, yielding decision‐based, topology‐driven coordination. When topological constraints are non‐local, as is the case for both connectivity and rigidity, we illustrate how consensus‐based decision‐making can preserve preemption while maintaining the feasibility of topological constraints. To evaluate the specific constraint of network connectedness, we propose an inverse iteration algorithm that estimates the eigenpair associated with algebraic connectivity. Our solution is fully distributed, scalable, and it improves on the convergence rate issues of the state of the art. Finally, as a case study of heterogeneity, we introduce a hybrid architecture in which a robotic network is dynamically reconfigured to ensure high quality information flow between static nodes while preserving connectivity. In solving this problem, we propose components that couple connectivity‐preserving robot‐to‐flow allocations, with distributed communication optimizing mobility; a heuristic we call Route Swarm. ❧ The second half of the thesis focuses on the rigidity property of a multi‐agent network. We provide a decentralized algorithm that determines a spanning edge set defining the minimally rigid subcomponent of a graph. Leader election manages sequential execution, and an asynchronous… Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Krishnamachari, Bhaskar (Committee Member), Jain, Rahul (Committee Member), Ioannou, Petros (Committee Member), Sha, Fei (Committee Member).

Subjects/Keywords: distributed robot systems; dynamic networks; graph connectivity; graph rigidity; multi‐robot coordination; sensor networks

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Williams, R. K. (2014). Interaction and topology in distributed multi-agent coordination. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/432814/rec/3570

Chicago Manual of Style (16^th Edition):

Williams, Ryan K. “Interaction and topology in distributed multi-agent coordination.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/432814/rec/3570.

MLA Handbook (7^th Edition):

Williams, Ryan K. “Interaction and topology in distributed multi-agent coordination.” 2014. Web. 26 Feb 2021.

Vancouver:

Williams RK. Interaction and topology in distributed multi-agent coordination. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/432814/rec/3570.

Council of Science Editors:

Williams RK. Interaction and topology in distributed multi-agent coordination. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/432814/rec/3570

University of Southern California

23. Jahanshahi, Mohammad Reza. Vision-based studies for structural health monitoring and condition assesment.

Degree: PhD, Civil Engineering, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/617318/rec/7842

► Automated health monitoring and maintenance of civil infrastructure systems is an active yet challenging area of research. Current structure inspection standards require an inspector to… (more)

▼ Automated health monitoring and maintenance of civil infrastructure systems is an active yet challenging area of research. Current structure inspection standards require an inspector to visually assess structure conditions. A less time-consuming and inexpensive alternative to current monitoring methods is to use a robotic system that can inspect structures more frequently, and perform autonomous damage detection. Nondestructive evaluation techniques (NDE) are innovative approaches for structural health monitoring. Among several possible techniques, the use of optical instrumentation (e.g., digital cameras), image processing and computer vision are promising approaches as nondestructive testing methods for structural health monitoring to complement sensor-based approaches. The feasibility of using image processing techniques to detect deterioration in structures has been acknowledged by leading researches in the field. This study represents the efforts that have been taken place by the author to form, implement, and evaluate several vision-based approaches that are promising for robust condition assessment of structures. ❧ It is well-recognized that civil infrastructure monitoring approaches that rely on visual approaches will continue to be an important methodology for condition assessment of such systems. Part of this study presents and evaluates the underlying technical elements for the development of an integrated inspection software tool that is based on the use of inexpensive digital cameras. For this purpose, digital cameras are appropriately mounted on a structure (e.g., a bridge) and can zoom or rotate in three directions (similar to traffic cameras). They are remotely controlled by an inspector, which allows the visual assessment of the structure’s condition by looking at images captured by the cameras. By not having to travel to the structures site, other issues related to safety considerations and traffic detouring are consequently bypassed. The proposed system gives an inspector the ability to compare the current (visual) situation of a structure with its former condition. If an inspector notices a defect in the current view, he/she can request a reconstruction of the same view using images that were previously captured and automatically stored in a database. Furthermore, by generating databases that consist of periodically captured images of a structure, the proposed system allows an inspector to evaluate the evolution of changes by simultaneously comparing the structure’s condition at different time periods. The essential components of the proposed virtual image reconstruction system are: keypoint detection, keypoint matching, image selection, outlier exclusion, bundle adjustment, composition, and cropping. Several illustrative examples are presented to demonstrate the capabilities, as well as the limitations, of the proposed vision-based inspection procedure. ❧ Visual inspection of structures is a highly qualitative method. If a region is inaccessible, binoculars must be used to detect and characterize… Advisors/Committee Members: Masri, Sami F. (Committee Chair), Lee, Jiin-Jen (Committee Member), Wellford, L. Carter (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: structural health monitoring; civil infrastructure systems; condition assessment; image processing; computer vision; pattern recognition; inspection tool; crack detection, crack quantification; corrosion detection; defect detection; change detection

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jahanshahi, M. R. (2013). Vision-based studies for structural health monitoring and condition assesment. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/617318/rec/7842

Chicago Manual of Style (16^th Edition):

Jahanshahi, Mohammad Reza. “Vision-based studies for structural health monitoring and condition assesment.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/617318/rec/7842.

MLA Handbook (7^th Edition):

Jahanshahi, Mohammad Reza. “Vision-based studies for structural health monitoring and condition assesment.” 2013. Web. 26 Feb 2021.

Vancouver:

Jahanshahi MR. Vision-based studies for structural health monitoring and condition assesment. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/617318/rec/7842.

Council of Science Editors:

Jahanshahi MR. Vision-based studies for structural health monitoring and condition assesment. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/617318/rec/7842

University of Southern California

24. Feil-Seifer, David J. Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders.

Degree: PhD, Computer Science, 2012, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/217625/rec/1775

► There exists a great untapped potential for the use of intelligent robots as therapeutic social partners for children. However, enabling a robot to understand social… (more)

▼ There exists a great untapped potential for the use of intelligent robots as therapeutic social partners for children. However, enabling a robot to understand social behavior, and do so while interacting with the child, is a challenging problem. Children are highly individual and thus technology used for social interaction requires recognition of a wide-range of social behavior. This argues for data-driven methods that capture the relevant range of interactions. This work addresses the challenge of designing data-driven behaviors for socially assistive robots in order to enable them to recognize and appropriately respond to a child's free-form behavior in unstructured play contexts. The focus on free-form behavior is inspired by and grounded in the DIR/Floortime approach to therapeutic intervention with children with autism spectrum disorders (ASD). This approach emphasizes fostering engagement through play, recognizing social behavior and using ""engagements"" to bolster social interactions. ❧ This research presents a data-driven methodology and a validated experimental framework for enabling fully autonomous robots to interact with both typically developing children and children with ASD in undirected scenarios using socially appropriate behavior, especially where spatial interaction is concerned. Autonomous robot operation as a critical aspect of the methodology; save for safety interventions by a human operator, the robot acts of its own accord. The robot and child engage in free-form interaction, in part though distance-oriented behaviors; the robot must be able to recognize the child's behaviors and respond to them appropriately. This dissertation presents the following computational contributions with therapeutic potential: ❧ Detection and mitigation of a child's distress: This work presents methodology for learning and then applying a data-driven spatio-temporal model of social behavior based on distance-based features to automatically differentiate between typical vs. aversive child-robot interactions. Using a Gaussian Mixture Model learned over distance-based feature data, the developed system is able to detect and interpret social behavior with sufficient accuracy to recognize child distress. The robot uses this model to change its own behavior so as to encourage positive social interaction. ❧ Encouragement of human-human and human-robot interaction: This work demonstrates a global and local motion planner that uses the above spatio-temporal model as part of the determination of a motion trajectory that maintains the robot's spatial relationship with the child and sustains interaction while also encouraging the child to move toward another proximal interaction partner. The desired spatial interaction behavior is achieved by modifying an established trajectory planner to weight candidate trajectories based on conformity to a trained model of the desired behavior. ❧ Data-Driven Approach For Providing Graded Cueing Feedback: A methodology for robot behavior that provides autonomous feedback for a robot-child… Advisors/Committee Members: Mataric', Maja J (Committee Chair), Sukhatme, Gaurav S. (Committee Member), Lajonchere, Clara (Committee Member), Cermak, Sharon A. (Committee Member).

Subjects/Keywords: human-robot interaction; autism; socially assistive robotics; behavior modeling; learning from demonstration; imitation; SAR; HRI; ASD

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Feil-Seifer, D. J. (2012). Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/217625/rec/1775

Chicago Manual of Style (16^th Edition):

Feil-Seifer, David J. “Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders.” 2012. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/217625/rec/1775.

MLA Handbook (7^th Edition):

Feil-Seifer, David J. “Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders.” 2012. Web. 26 Feb 2021.

Vancouver:

Feil-Seifer DJ. Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders. [Internet] [Doctoral dissertation]. University of Southern California; 2012. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/217625/rec/1775.

Council of Science Editors:

Feil-Seifer DJ. Data-driven interaction methods for socially assistive robotics: validation with children with autism spectrum disorders. [Doctoral Dissertation]. University of Southern California; 2012. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/217625/rec/1775

University of Southern California

25. Zhao, Yili. Plant substructuring and real-time simulation using model reduction.

Degree: PhD, Computer Science, 2014, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/462785/rec/5065

► This research is focusing on real‐time, physically‐based simulation of plants undergoing large deformations. To achieve this goal, we first propose a novel algorithm based on… (more)

▼ This research is focusing on real‐time, physically‐based simulation of plants undergoing large deformations. To achieve this goal, we first propose a novel algorithm based on model reduction and domain decomposition. It extends 3D nonlinear elasticity model reduction to open‐loop multi‐level reduced deformable structures. We decompose the input mesh into several domains, build a reduced deformable model for every domain, simulate each one separately, and connect domains using proper inertia coupling. This makes model reduction deformable simulations much more versatile: localized deformations can be supported without prohibitive computational costs, parts can be re‐used and precomputation time can be shortened. Our method does not use constraints, and can handle large domain rigid body motion in addition to large deformations, due to our derivation of the gradient and Hessian of the rotation matrix in polar decomposition. We show real‐time examples with multi‐level domain hierarchies and thousands of reduced degrees of freedom. ❧ Then we design a pre‐processor which takes a plant “polygon soup” triangle mesh as the only input and quickly pre‐compute necessary data for the subsequent simulation. This tool breaks the ice for adoption of our multidomain dynamics simulator in practice. Our pre‐processor is robust to non‐manifold input geometry, gaps between branches or leaves, free‐flying leaves not connected to any branch, small unimportant geometry (“debris”) left in the model, and plant self‐collisions in the input configuration. Repeated copies (instances) of plant subparts such as leaves, petals or fruits can be automatically detected by our pre‐processor. ❧ We enhanced our multidomain dynamics simulator to provide plant fracture, and inverse kinematics to easily pose plants. It can simulate complex plants at interactive rates, subjected to user forces, gravity or randomized wind. We simulated over 100 plants from diverse climates and geographic regions, including broadleaf (deciduous) trees and conifers, bushes and flowers. Our largest simulations involve anatomically realistic adult trees with hundreds of branches and over 100,000 leaves. ❧ Finally, we propose our future research in several directions including adding hierarchical instancing, collision detection and handling, etc. Advisors/Committee Members: Barbic, JernejBarbič, Jernej (Committee Chair), Kukavica, Igor (Committee Member), Neumann, Ulrich (Committee Member), Sukhatme, Gaurav S. (Committee Member), Schaal, Stefan (Committee Member).

Subjects/Keywords: model reduction; substructuring; domain decomposition; FEM; nonlinear elasticity; botanical; plant; authoring; interactive; large deformations; computer graphics; computer animation; physically‐based simulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zhao, Y. (2014). Plant substructuring and real-time simulation using model reduction. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/462785/rec/5065

Chicago Manual of Style (16^th Edition):

Zhao, Yili. “Plant substructuring and real-time simulation using model reduction.” 2014. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/462785/rec/5065.

MLA Handbook (7^th Edition):

Zhao, Yili. “Plant substructuring and real-time simulation using model reduction.” 2014. Web. 26 Feb 2021.

Vancouver:

Zhao Y. Plant substructuring and real-time simulation using model reduction. [Internet] [Doctoral dissertation]. University of Southern California; 2014. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/462785/rec/5065.

Council of Science Editors:

Zhao Y. Plant substructuring and real-time simulation using model reduction. [Doctoral Dissertation]. University of Southern California; 2014. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/462785/rec/5065

University of Southern California

26. Kelly, Jonathan Scott. On temporal and spatial calibration for high accuracy visual-inertial motion estimation.

Degree: PhD, Computer Science, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198919/rec/4534

► The majority of future autonomous robots will be mobile, and will need to navigate reliably in unknown and dynamic environments. Visual and inertial sensors, together,… (more)

▼ The majority of future autonomous robots will be mobile, and will need to navigate reliably in unknown and dynamic environments. Visual and inertial sensors, together, are able to supply accurate motion estimates and are well-suited for use in many robot navigation tasks. Beyond egomotion estimation, fusing high-rate inertial sensing with monocular vision enables other capabilities, such as independent motion segmentation and tracking, moving obstacle detection and ranging, and dense metric 3D mapping, all from a mobile platform. ❧ A fundamental requirement in any multisensor system is precision calibration. To ensure optimal performance, the sensors must be properly calibrated, both intrinsically and relative to one another. In a visual-inertial system, the camera and the inertial measurement unit (IMU) require both temporal and spatial calibration – estimates of the relative timing of measurements from each sensor and of the six degrees-of-freedom transform between the sensors are needed. Obtaining this calibration information is typically difficult and time-consuming, however. Ideally, we would like to build power-on-and-go robots that are able to operate for long periods without the usual requisite manual sensor (re-) calibration. ❧ This dissertation describes work on combining visual and inertial sensing for navigation applications, with an emphasis on the ability to temporally and spatially (self-) calibrate a camera and an IMU. Self-calibration refers to the use of data exclusively from the sensors themselves to improve estimates of related system parameters. ❧ The primary difficultly in temporal calibration is that the correspondences between measurements from the different sensors are initially unknown, and hence the relative time delay between the data streams cannot be computed directly. We instead formulate temporal calibration as a registration problem, and introduce an algorithm called Time Delay Iterative Closest Point (TD-ICP) as a novel solution. The algorithm operates by aligning curves in a three-dimensional orientation space, and incorporates in a principled way the uncertainty in the camera and IMU measurements. ❧ We then develop a sequential filtering approach for calibration of the spatial transform between the sensors. We estimate the transform parameters using a sigma point Kalman filter (SPKF). Our formulation rests on a differential geometric analysis of the observability of the camera-IMU system; this analysis shows for the first time that the IMU pose and velocity, the gyroscope and accelerometer biases, the gravity vector, the metric scene structure, and the sensor-to-sensor transform, can be recovered from camera and IMU measurements alone. While calibrating the transform we simultaneously localize the IMU and build a map of the surroundings. No additional hardware or prior knowledge about the environment in which a robot is operating is necessary. ❧ Results from extensive simulation studies and from laboratory experiments are presented, which demonstrate accurate camera-IMU temporal… Advisors/Committee Members: Sukhatme, Gaurav S. (Committee Chair), Schaal, Stefan (Committee Member), Matthies, Larry H. (Committee Member), Newton, Paul K. (Committee Member).

Subjects/Keywords: calibration; inertial navigation; simultaneous localization and mapping; SLAM; sensor fusion; monocular vision; observability

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APA (6^th Edition):

Kelly, J. S. (2011). On temporal and spatial calibration for high accuracy visual-inertial motion estimation. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198919/rec/4534

Chicago Manual of Style (16^th Edition):

Kelly, Jonathan Scott. “On temporal and spatial calibration for high accuracy visual-inertial motion estimation.” 2011. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198919/rec/4534.

MLA Handbook (7^th Edition):

Kelly, Jonathan Scott. “On temporal and spatial calibration for high accuracy visual-inertial motion estimation.” 2011. Web. 26 Feb 2021.

Vancouver:

Kelly JS. On temporal and spatial calibration for high accuracy visual-inertial motion estimation. [Internet] [Doctoral dissertation]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198919/rec/4534.

Council of Science Editors:

Kelly JS. On temporal and spatial calibration for high accuracy visual-inertial motion estimation. [Doctoral Dissertation]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198919/rec/4534

University of Southern California

27. Theodorou, Evangelos A. Iterative path integral stochastic optimal control: theory and applications to motor control.

Degree: PhD, Computer Science, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/468575/rec/3680

► Motivated by the limitations of current optimal control and reinforcement learning methods in terms of their efficiency and scalability, this thesis proposes an iterative stochastic… (more)

▼ Motivated by the limitations of current optimal control and reinforcement learning methods in terms of their efficiency and scalability, this thesis proposes an iterative stochastic optimal control approach based on the generalized path integral formalism. More precisely, we suggest the use of the framework of stochastic optimal control with path integrals to derive a novel approach to RL with parameterized policies. While solidly grounded in value function estimation and optimal control based on the stochastic Hamilton Jacobi Bellman (HJB) equation, policy improvements can be transformed into an approximation problem of a path integral which has no open algorithmic parameters other than the exploration noise. The resulting algorithm can be conceived of as model-based, semi-model-based, or even model free, depending on how the learning problem is structured. The new algorithm, Policy Improvement with Path Integrals (PI2), demonstrates interesting similarities with previous RL research in the framework of probability matching and provides intuition why the slightly heuristically motivated probability matching approach can actually perform well. Applications to high dimensional robotic systems are presented for a variety of tasks that require optimal planning and gain scheduling.; In addition to the work on generalized path integral stochastic optimal control, in this thesis we extend model based iterative optimal control algorithms to the stochastic setting. More precisely we derive the Differential Dynamic Programming algorithm for stochastic systems with state and control multiplicative noise. Finally, in the last part of this thesis, model based iterative optimal control methods are applied to bio-mechanical models of the index finger with the goal to find the underlying tendon forces applied for the movements of, tapping and flexing. Advisors/Committee Members: Schaal, Stefan (Committee Chair), Valero-Cuevas, Francisco (Committee Member), Sukhatme, Gaurav S. (Committee Member), Todorov, Emo (Committee Member), Schweighofer, Nicolas (Committee Member).

Subjects/Keywords: stochastic optimal control; reinforcement learning,; robotics

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APA (6^th Edition):

Theodorou, E. A. (2011). Iterative path integral stochastic optimal control: theory and applications to motor control. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/468575/rec/3680

Chicago Manual of Style (16^th Edition):

Theodorou, Evangelos A. “Iterative path integral stochastic optimal control: theory and applications to motor control.” 2011. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/468575/rec/3680.

MLA Handbook (7^th Edition):

Theodorou, Evangelos A. “Iterative path integral stochastic optimal control: theory and applications to motor control.” 2011. Web. 26 Feb 2021.

Vancouver:

Theodorou EA. Iterative path integral stochastic optimal control: theory and applications to motor control. [Internet] [Doctoral dissertation]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/468575/rec/3680.

Council of Science Editors:

Theodorou EA. Iterative path integral stochastic optimal control: theory and applications to motor control. [Doctoral Dissertation]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/468575/rec/3680

University of Southern California

28. Stauffer, Beth Ann. Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control.

Degree: PhD, Marine and Environmental Biology, 2011, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198718/rec/5060

► Nearshore coastal environments are common sites of episodic and stochastic events that rapidly alter the physics and chemistry of the water column and thereby affect… (more)

▼ Nearshore coastal environments are common sites of episodic and stochastic events that rapidly alter the physics and chemistry of the water column and thereby affect plankton biomass and community structure. The dominant factors controlling the manner in which the pelagic communities responds to these changes are still poorly understood owing in part to their episodic nature and in part because they often rely on observations made at low temporal/spatial resolution and correlations between instantaneously measured conditions to draw relationships between the biological and physico-chemical parameters. King Harbor is a small, semi-enclosed recreational embayment within Santa Monica Bay. Nonlinear time-series and linear multiple regression analyses of a high-resolution, year-long dataset allowed an in-depth investigation of the relationship between various chemical/physical factors and algal biomass. A significant relationship with the tidal cycle was manifest primarily as increased biomass and bloom initiation during or in the days following neap tide, especially in the hydrodynamically-constrained northern basin of the harbor. Local histories of dissolved nitrate and salinity were also significant predictors of increased biomass, as was reduced wind speed. ❧ A major fish mortality in King Harbor 8 March 2011 killed approximately 170 tons of fish (Pacific sardine) and garnered international attention as a marine system out of balance. In situ sensors present in the harbor prior to, during and after the event revealed rapid decreases in dissolved oxygen in surface waters from 7-9 March 2011, coincident with the fish mortality event. Continuous and automated observations provided evidence that fish respiration, exacerbated by an incursion of upwelled low-oxygen water, was the immediate cause of fish mortality. The hydrodynamically-constrained northern basin transitioned to extreme and sustained hypoxic conditions while spatially-variable hypoxia was also observed throughout the harbor and adjacent bay for more than ten days following the event. Initial recovery of dissolved oxygen in the harbor was facilitated by storm-mediated mixing of the water column. A trophic shift was observed throughout King Harbor concomitant with dramatic changes in water column chemistry associated with the fish kill. Relative abundances of bacterivorous ciliates increased up to > 80% in the weeks following the fish kill. Multivariate analyses also revealed significant temporal dissimilarity in microplankton community composition and trophic structure within King Harbor during hypoxia, subsequent storm-mediated mixing events, and following the storm. Finally, dramatically reduced photosynthetic yield by the phytoplankton in the northern basis indicated severe physiological stress of the phototroph population during the extreme hypoxia. ❧ Top-down control on phytoplankton populations was examined through experimental studies of the interactions between the heterotrophic dinoflagellate Noctiluca scintillans and several red-tide forming algal… Advisors/Committee Members: Caron, David A. (Committee Chair), Jones, Burton H. (Committee Member), Heidelberg, Karla B. (Committee Member), Kiefer, Dale A. (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: harmful algal blooms; phytoplankton; protistan grazing; tidal forcing

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Stauffer, B. A. (2011). Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198718/rec/5060

Chicago Manual of Style (16^th Edition):

Stauffer, Beth Ann. “Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control.” 2011. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198718/rec/5060.

MLA Handbook (7^th Edition):

Stauffer, Beth Ann. “Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control.” 2011. Web. 26 Feb 2021.

Vancouver:

Stauffer BA. Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control. [Internet] [Doctoral dissertation]. University of Southern California; 2011. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198718/rec/5060.

Council of Science Editors:

Stauffer BA. Plankton dynamics in a nearshore coastal environment: responses to short-term environmental fluctuations and top-down control. [Doctoral Dissertation]. University of Southern California; 2011. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/198718/rec/5060

University of Southern California

29. Seubert, Erica Lee. Distribution and impact of algal blooms leading to domoic acid events in southern California.

Degree: PhD, Marine and Environmental Biology, 2013, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/318562/rec/2054

► The term harmful algal bloom (HAB) is used to describe any bloom of microalgae that has a detrimental impact to the local ecosystem and/or economy.… (more)

▼ The term harmful algal bloom (HAB) is used to describe any bloom of microalgae that has a detrimental impact to the local ecosystem and/or economy. The impacts of a HAB to an ecosystem can include death or injury to local wildlife through the production of toxins, decreased oxygen concentrations, physical damage, decreased light availability or food web disturbance. The economic impacts can be reduction in tourism, human illness, reduced fishing effort or interruption of desalination plant operations. The occurrence and intensity of HABs have been increasing globally during the past few decades, whether this increase can be attributed to enhanced awareness and monitoring, or to a dramatic upswing in the development of HAB events remains unresolved. ❧ A variety of HAB-forming species of microalgae occur in southern California, and several of these species are known to produce potent neurotoxins. The impact of algal toxin presence on both the intake and reverse osmosis (RO) desalination process and whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product was addressed through bench-scale RO experiments and monitoring for algal toxins at a pilot RO desalination plant. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 µg/L of domoic acid (DA), 2 µg/L of saxitoxin (STX) and 20 µg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular toxin concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the ability of typical RO operations to effectively remove these toxins. ❧ The ability to accurately and rapidly identify an emerging HAB event is of high importance. Monitoring of HAB species and other pertinent chemical/physical parameters at two piers in southern California, Newport and Redondo Beach, was used to investigate the development of a site-specific bloom definition for identifying emerging DA events. The neurotoxin DA is produced by the chain forming diatom Pseudo-nitzschia, and it is the most common HAB organism in southern California. Emphasis was given to abundances of the P. seriata size category of Pseudo-nitzschia due to the prevalence of this size class in the region. P. seriata bloom thresholds were established for each location based on deviations from their respective long-term mean abundances, allowing the identification of major and minor blooms. Sixty five percent of… Advisors/Committee Members: Caron, David A. (Committee Chair), Hutchins, David A. (Committee Member), Sanudo-Wilhelmy, Sergio A. (Committee Member), Sañudo-Wilhelmy, Sergio A. (Committee Member), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: harmful algal blooms; Pseudo-nitzschia; domoic acid; saxitoxin; HAB monitoring; desalination; okadaic acid; brevetoxin; California sea lion; ELISA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Seubert, E. L. (2013). Distribution and impact of algal blooms leading to domoic acid events in southern California. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/318562/rec/2054

Chicago Manual of Style (16^th Edition):

Seubert, Erica Lee. “Distribution and impact of algal blooms leading to domoic acid events in southern California.” 2013. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/318562/rec/2054.

MLA Handbook (7^th Edition):

Seubert, Erica Lee. “Distribution and impact of algal blooms leading to domoic acid events in southern California.” 2013. Web. 26 Feb 2021.

Vancouver:

Seubert EL. Distribution and impact of algal blooms leading to domoic acid events in southern California. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/318562/rec/2054.

Council of Science Editors:

Seubert EL. Distribution and impact of algal blooms leading to domoic acid events in southern California. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/318562/rec/2054

University of Southern California

30. Meesookho, Chartchai. Robust acoustic source localization in sensor networks.

Degree: PhD, Electrical Engineering, 2007, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/536859/rec/5615

► Our goal is to improve the performance of acoustic source localization in the context of sensor networks. A number of relevant problems are addressed and… (more)

▼ Our goal is to improve the performance of acoustic source localization in the context of sensor networks. A number of relevant problems are addressed and solutions are proposed.; As data is usually collected by sensors with randomly distributed locations, a problem that emerged for source localization is how to efficiently gather all the required data and combine them subject to selected localization schemes. In Chapter 3, we propose a distributed algorithm based on a specific method, range difference based localization. Simulation results illustrate that the distributed localization produces smaller error and consumes less energy than centralized method. The advantage of distributed processing becomes more conspicuous for error considerations when the number of participating sensors is small and obtains more energy saving with the large number of participating sensor. The proposed method is also more robust to decreasing target signal energy and the instantaneous error from the sequence of estimates can be approximated and used to reconcile the cost and the system performance.; Considering recently proposed methods, energy based localization attracts our interest due to their simplicity and the possibility of earning energy saving while maintaining acceptable accuracy. The investigation of existing energy based methods leads to findings that show the possibility of further improvement. In Chapter 4, energy-based localization methods for source localization in sensor networks are examined. The focus is on least squares based approaches due to a good trade-off between performance and complexity. A suite of methods are developed and compared. First, two previously proposed methods (Quadratic Elimination and One Step) are shown to yield the same location estimate for a source. Next, it is shown that as the errors which perturb the least squares equations are non-identically distributed, it is more appropriate to consider weighted least squares methods which is observed to yield significant performance gains over the unweighted methods. Finally, a new weighted direct least squares formulation is presented and shown to outperform the previous methods with much less computational complexity. Unlike the Quadratic Elimination method, the weighted direct least squares method is amenable to a correction technique which incorporates the dependence of unknown parameters leading to further performance gains. For a sufficiently large number of samples, simulations show that the Weighted Direct solution with Correction (WDC) can be more accurate with significantly less computational complexity than the maximum likelihood estimator and approaches Cramér-Rao Bound (CRB). Furthermore, it is shown that WDC attains CRB for the case of a white source.; Since the consideration of system design is inevitably important, in Chapter 5, design rules for sensor network deployment for acoustic source localization are determined. In particular, methods based on time-delay information in the received acoustic signal time series and those based on… Advisors/Committee Members: Narayanan, Shrikanth S.Mitra, Urbashi (Committee Chair), Sukhatme, Gaurav S. (Committee Member).

Subjects/Keywords: acoustic; localization; sensor; networks

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Meesookho, C. (2007). Robust acoustic source localization in sensor networks. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/536859/rec/5615

Chicago Manual of Style (16^th Edition):

Meesookho, Chartchai. “Robust acoustic source localization in sensor networks.” 2007. Doctoral Dissertation, University of Southern California. Accessed February 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/536859/rec/5615.

MLA Handbook (7^th Edition):

Meesookho, Chartchai. “Robust acoustic source localization in sensor networks.” 2007. Web. 26 Feb 2021.

Vancouver:

Meesookho C. Robust acoustic source localization in sensor networks. [Internet] [Doctoral dissertation]. University of Southern California; 2007. [cited 2021 Feb 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/536859/rec/5615.

Council of Science Editors:

Meesookho C. Robust acoustic source localization in sensor networks. [Doctoral Dissertation]. University of Southern California; 2007. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/536859/rec/5615

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Open Access Theses and Dissertations