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Georgia Tech
1.
Xing, Xin.
The proxy point method for rank-structured matrices.
Degree: PhD, Mathematics, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/62327 
► Rank-structured matrix representations, e.g., \mathcal{H}2 and HSS, are commonly used to reduce computation and storage cost for dense matrices defined by interactions between many bodies.…
(more)
▼ Rank-structured matrix representations, e.g., \mathcal{H}
2 and HSS, are commonly used to reduce computation and storage cost for dense matrices defined by interactions between many bodies. The main bottleneck for their application is the expensive computation required to represent a matrix in a rank-structured matrix format which involves compressing specific matrix blocks into low-rank form. This dissertation is mainly about the study and application of a hybrid analytic-algebraic compression method, called it{the proxy point method}. This work uncovers the full strength of this presently underutilized method that could potentially resolve the above bottleneck for all rank-structured matrix techniques. As a result, this work could extend the applicability and improve the performance of rank-structured matrix techniques and thus facilitate dense matrix computations in a wider range of scientific computing problems, such as particle simulations, numerical solution of integral equations, and Gaussian processes. Application of the proxy point method in practice is presently very limited. Only two special instances of the method have been used heuristically to compress interaction blocks defined by specific kernel functions over points. We address several critical problems of the proxy point method which limit its applicability. A general form of the method is then proposed, paving the way for its wider application in the construction of different rank-structured matrix representations with kernel functions that are more general than those usually used. In addition to kernel-defined interactions between points, we further extend the applicability of the proxy point method to compress the interactions between charge distributions in quantum chemistry calculations. Specifically, we propose a variant of the proxy point method to efficiently construct an \mathcal{H}
2 matrix representation of the four-dimensional electron repulsion integral tensor. The linear-scaling matrix-vector multiplication algorithm for the constructed \mathcal{H}
2 matrix is then used for fast Coulomb matrix construction which is an important step in many quantum chemical methods. Two additional contributions related to \mathcal{H}
2 and HSS matrices are also presented. First, we explain the exact equivalence between \mathcal{H}
2 matrices and the fast multipole method (FMM). This equivalence has not been rigorously studied in the literature. Numerical comparisons between FMM and \mathcal{H}
2 matrices based on the proxy point method are also provided, showing the relative advantages and disadvantages of the two methods. Second, we consider the application of HSS approximations as preconditioners for symmetric positive definite (SPD) matrices. Preserving positive definiteness is essential for rank-structured matrix approximations to be used efficiently in various algorithms and applications, e.g., the preconditioned conjugate gradient method. We propose two methods for constructing HSS approximations to an SPD matrix that preserve…
Advisors/Committee Members: Chow, Edmond (advisor), Sherrill, David (committee member), Xia, Jianlin (committee member), Xi, Yuanzhe (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Rank-structured matrices; Low-rank approximation; Kernel matrices; Numerical linear algebra
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APA (6th Edition):
Xing, X. (2019). The proxy point method for rank-structured matrices. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62327
Chicago Manual of Style (16th Edition):
Xing, Xin. “The proxy point method for rank-structured matrices.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/62327.
MLA Handbook (7th Edition):
Xing, Xin. “The proxy point method for rank-structured matrices.” 2019. Web. 05 Mar 2021.
Vancouver:
Xing X. The proxy point method for rank-structured matrices. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/62327.
Council of Science Editors:
Xing X. The proxy point method for rank-structured matrices. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62327
Georgia Tech
2.
Lateef, Omer G.
Measurement-based parameter estimation and analysis of power system.
Degree: PhD, Electrical and Computer Engineering, 2020, Georgia Tech
URL: http://hdl.handle.net/1853/63600
► Currently, power systems are modeled using the offline models of its components. The components’ models are derived during their design. Such an offline approach of…
(more)
▼ Currently, power systems are modeled using the offline models of its components. The components’ models are derived during their design. Such an offline approach of modeling can result in an erroneous model of a power system since it neglects any changes in the parameters of the components. The parameters of the components vary with the loading and atmospheric conditions. These variations can be taken into account if, instead of the offline models of the components, real-time measurements are used to derive a model of power system. Various such measurement-based approaches have been used in the current study to estimate the bus admittance matrix and the bus impedance matrix of a power system. From the estimated bus admittance matrix, the parameters and the topology of the power system are derived. From the parameters, the condition of the components can be assessed. Moreover, a novel decentralized and distributed algorithm is used for the estimation of the bus impedance matrix. After the algorithm converges, the respective columns of the bus impedance matrix are available which can be used to update the settings of the relays. The relays set in such a way will better protect the power system
Advisors/Committee Members: Habetler, Thomas G. (advisor), Molzahn, Daniel (committee member), Grijalva, Santiago C. (committee member), Graber, Lukas (committee member), Zhou , Haomin (committee member).
Subjects/Keywords: PMU; Power system
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APA (6th Edition):
Lateef, O. G. (2020). Measurement-based parameter estimation and analysis of power system. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/63600
Chicago Manual of Style (16th Edition):
Lateef, Omer G. “Measurement-based parameter estimation and analysis of power system.” 2020. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/63600.
MLA Handbook (7th Edition):
Lateef, Omer G. “Measurement-based parameter estimation and analysis of power system.” 2020. Web. 05 Mar 2021.
Vancouver:
Lateef OG. Measurement-based parameter estimation and analysis of power system. [Internet] [Doctoral dissertation]. Georgia Tech; 2020. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/63600.
Council of Science Editors:
Lateef OG. Measurement-based parameter estimation and analysis of power system. [Doctoral Dissertation]. Georgia Tech; 2020. Available from: http://hdl.handle.net/1853/63600
Georgia Tech
3.
Lu, Jun.
Method of evolving junctions: a new approach to path planning and optimal control.
Degree: PhD, Mathematics, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53428
► This thesis proposes a novel and efficient method (Method of Evolving Junctions) for solving optimal control problems with path constraints, and whose optimal paths are…
(more)
▼ This thesis proposes a novel and efficient method (Method of Evolving Junctions)
for solving optimal control problems with path constraints, and whose optimal
paths are separable. A path is separable if it is the concatenation of finite
number of subarcs that are optimal and either entirely constraint active or
entirely constraint inactive. In the case when the subarcs can be computed
efficiently, the search for the optimal path boils down to determining the
junctions that connect those subarcs. In this way, the original infinite
dimensional problem of finding the entire path is converted into a finite
dimensional problem of determine the optimal junctions. The finite dimensional
optimization problem is then solved by a recently developed global optimization
strategy, intermittent diffusion. The idea is to add perturbations (noise) to
the gradient flow intermittently, which essentially converts the ODE's (gradient
descent) into a SDE's problem. It can be shown that the probability of finding
the globally optimal path can be arbitrarily close to one. Comparing to existing
methods, the method of evolving junctions is fundamentally faster and able to
find the globally optimal path as well as a series of locally optimal paths.
The efficiency of the algorithm will be demonstrated by solving path planning
problems, more specifically, finding the optimal path in cluttered environments
with static or dynamic obstacles.
Advisors/Committee Members: Zhou, Haomin (advisor), Chow, Shui-Nee (committee member), Dieci, Luca (committee member), Egerstedt, Magnus (committee member), Kang, Sung Ha (committee member).
Subjects/Keywords: SDEs; Shortest path; Dynamic environment
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APA (6th Edition):
Lu, J. (2014). Method of evolving junctions: a new approach to path planning and optimal control. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53428
Chicago Manual of Style (16th Edition):
Lu, Jun. “Method of evolving junctions: a new approach to path planning and optimal control.” 2014. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/53428.
MLA Handbook (7th Edition):
Lu, Jun. “Method of evolving junctions: a new approach to path planning and optimal control.” 2014. Web. 05 Mar 2021.
Vancouver:
Lu J. Method of evolving junctions: a new approach to path planning and optimal control. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/53428.
Council of Science Editors:
Lu J. Method of evolving junctions: a new approach to path planning and optimal control. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53428
Georgia Tech
4.
Exarchos, Ioannis.
Stochastic optimal control - a forward and backward sampling approach.
Degree: PhD, Aerospace Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/59263
► Stochastic optimal control has seen significant recent development, motivated by its success in a plethora of engineering applications, such as autonomous systems, robotics, neuroscience, and…
(more)
▼ Stochastic optimal control has seen significant recent development, motivated by its success in a plethora of engineering applications, such as autonomous systems, robotics, neuroscience, and financial engineering. Despite the many theoretical and algorithmic advancements that made such a success possible, several obstacles remain; most notable are (i) the mitigation of the curse of dimensionality inherent in optimal control problems, (ii) the design of efficient algorithms that allow for fast, online computation, and (iii) the expansion of the class of optimal control problems that can be addressed by algorithms in engineering practice. The aim of this dissertation is the development of a learning stochastic control framework which capitalizes on the innate relationship between certain nonlinear partial differential equations (PDEs) and forward and backward stochastic differential equations (FBSDEs), demonstrated by a nonlinear version of the Feynman-Kac lemma. By means of this lemma, we are able to obtain a probabilistic representation of the solution to the nonlinear Hamilton-Jacobi-Bellman PDE, expressed in form of a system of decoupled FBSDEs. This system of FBSDEs can then be simulated by employing linear regression techniques. We present a novel discretization scheme for FBSDEs, and enhance the resulting algorithm with importance sampling, thereby constructing an iterative scheme that is capable of learning the optimal control without an initial guess, even in systems with highly nonlinear, underactuated dynamics. The framework we develop within this dissertation addresses several classes of stochastic optimal control, such as L2, L1, risk sensitive control, as well as some classes of differential games, in both fixed-final-time as well as first-exit settings.
Advisors/Committee Members: Tsiotras, Panagiotis (advisor), Theodorou, Evangelos A. (advisor), Haddad, Wassim M. (committee member), Zhou, Haomin (committee member), Popescu, Ionel (committee member).
Subjects/Keywords: Stochastic optimal control; Forward and backward stochastic differential equations
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APA ·
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APA (6th Edition):
Exarchos, I. (2017). Stochastic optimal control - a forward and backward sampling approach. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59263
Chicago Manual of Style (16th Edition):
Exarchos, Ioannis. “Stochastic optimal control - a forward and backward sampling approach.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/59263.
MLA Handbook (7th Edition):
Exarchos, Ioannis. “Stochastic optimal control - a forward and backward sampling approach.” 2017. Web. 05 Mar 2021.
Vancouver:
Exarchos I. Stochastic optimal control - a forward and backward sampling approach. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/59263.
Council of Science Editors:
Exarchos I. Stochastic optimal control - a forward and backward sampling approach. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59263
Georgia Tech
5.
Kim, Woongrae.
Design and test methodologies with statistical analysis for reliable memory and processor implementations.
Degree: PhD, Electrical and Computer Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/59737
► The object of the proposed research is to develop comprehensive methodologies, including circuit design, new test methodologies, and statistical failure analysis, to implement reliable microprocessor…
(more)
▼ The object of the proposed research is to develop comprehensive methodologies, including circuit design, new test methodologies, and statistical failure analysis, to implement reliable microprocessor and main memory systems. For a microprocessor, we have focused on the reliability issues in the embedded cache, since SRAMs are designed with the tightest design rules, and high performance processors are expected to consist of a large embedded memory. Also, to solve the scaling challenges for the main memory system, we have studied optimized design schemes for the 3D DRAM system, to achieve better performance, reliability, cost, and power.
Advisors/Committee Members: Milor, Linda (advisor), Chatterjee, Abhijit (committee member), Naeemi, Azad (committee member), Schimmel, David (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Reliability; SRAM; DRAM; Processor
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APA (6th Edition):
Kim, W. (2016). Design and test methodologies with statistical analysis for reliable memory and processor implementations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59737
Chicago Manual of Style (16th Edition):
Kim, Woongrae. “Design and test methodologies with statistical analysis for reliable memory and processor implementations.” 2016. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/59737.
MLA Handbook (7th Edition):
Kim, Woongrae. “Design and test methodologies with statistical analysis for reliable memory and processor implementations.” 2016. Web. 05 Mar 2021.
Vancouver:
Kim W. Design and test methodologies with statistical analysis for reliable memory and processor implementations. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/59737.
Council of Science Editors:
Kim W. Design and test methodologies with statistical analysis for reliable memory and processor implementations. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/59737
Georgia Tech
6.
Hu, Lili.
Numerical algorithms based on the back and forth error compensation and correction.
Degree: PhD, Mathematics, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/54839
► In this thesis we carry out a further study of the back and forth error compensation and correction (BFECC) method. The first part discusses the…
(more)
▼ In this thesis we carry out a further study of the back and forth error compensation and correction (BFECC) method. The first part discusses the time reversibility of numerical schemes. Motivated by the BFECC method, a variety of new numeri- cal schemes that aim at improving the time reversibility are developed and studied. We also introduce an interpolation algorithm based on BFECC in this part. In the second part we introduce a new limiting strategy which requires another backward advection in time so that overshoots/undershoots at the new time level get exposed when they are transformed back to compare with the solution at the old time level. This new technique is very simple to implement even for unstructured meshes and is able to eliminate artifacts induced by jump discontinuities in the solution itself or in its derivatives.
Advisors/Committee Members: Liu, Yingjie (advisor), Zhou, Haomin (committee member), Dieci, Luca (committee member), Rossignac, Jarek (committee member), Kang, Sung Ha (committee member).
Subjects/Keywords: BFECC; Limiting strategy; Time reversible algorithms
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APA ·
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APA (6th Edition):
Hu, L. (2014). Numerical algorithms based on the back and forth error compensation and correction. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54839
Chicago Manual of Style (16th Edition):
Hu, Lili. “Numerical algorithms based on the back and forth error compensation and correction.” 2014. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/54839.
MLA Handbook (7th Edition):
Hu, Lili. “Numerical algorithms based on the back and forth error compensation and correction.” 2014. Web. 05 Mar 2021.
Vancouver:
Hu L. Numerical algorithms based on the back and forth error compensation and correction. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/54839.
Council of Science Editors:
Hu L. Numerical algorithms based on the back and forth error compensation and correction. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54839
Georgia Tech
7.
Li, Wuchen.
A study of stochastic differential equations and Fokker-Planck equations with applications.
Degree: PhD, Mathematics, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/54999
► Fokker-Planck equations, along with stochastic differential equations, play vital roles in physics, population modeling, game theory and optimization (finite or infinite dimensional). In this thesis,…
(more)
▼ Fokker-Planck equations, along with stochastic differential equations, play vital roles in physics, population modeling, game theory and optimization (finite or infinite dimensional). In this thesis, we study three topics, both theoretically and computationally, centered around them. In part one, we consider the optimal transport for finite discrete states, which are on a finite but arbitrary graph. By defining a discrete 2-Wasserstein metric, we derive Fokker-Planck equations on finite graphs as gradient flows of free energies. By using dynamical viewpoint, we obtain an exponential convergence result to equilibrium. This derivation provides tools for many applications, including numerics for nonlinear partial differential equations and evolutionary game theory. In part two, we introduce a new stochastic differential equation based framework for optimal control with constraints. The framework can efficiently solve several real world problems in differential games and Robotics, including the path-planning problem. In part three, we introduce a new noise model for stochastic oscillators. With this model, we prove global boundedness of trajectories. In addition, we derive a pair of associated Fokker-Planck equations.
Advisors/Committee Members: Dieci, Luca (advisor), Chow, Shui Nee (committee member), Zhou, Haomin (committee member), Egerstedt, Magnus (committee member), Gangbo, Wilfrid (committee member).
Subjects/Keywords: Stochastic differential equations; Fokker-Planck equations; Gradient flow; Optimal control; Optimal transport
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APA (6th Edition):
Li, W. (2016). A study of stochastic differential equations and Fokker-Planck equations with applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54999
Chicago Manual of Style (16th Edition):
Li, Wuchen. “A study of stochastic differential equations and Fokker-Planck equations with applications.” 2016. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/54999.
MLA Handbook (7th Edition):
Li, Wuchen. “A study of stochastic differential equations and Fokker-Planck equations with applications.” 2016. Web. 05 Mar 2021.
Vancouver:
Li W. A study of stochastic differential equations and Fokker-Planck equations with applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/54999.
Council of Science Editors:
Li W. A study of stochastic differential equations and Fokker-Planck equations with applications. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/54999
Georgia Tech
8.
Choi, Sun.
A multi-level predictive methodology for terminal area air traffic flow.
Degree: PhD, Aerospace Engineering, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/61196
► Over the past few decades, the air transportation system has grown significantly. In particular, the number of passengers using air transportation has greatly increased. As…
(more)
▼ Over the past few decades, the air transportation system has grown significantly. In particular, the number of passengers using air transportation has greatly increased. As the demand for air travel expands, airport departure/arrival demand almost reaches its capacity. In consequence, the level of delays increases since the system capacity cannot manage the increased demand. With this trend, the national airspace system (NAS) will be saturated, and the congestion at the airport will become even more severe. As a result of congestion, a considerable number of flights experience delays. According to the Bureau of Transportation Statistics (BTS), over 1 million flights are operated in a year, and about twenty percent of all scheduled commercial flights are delayed more than 15 minutes. These delays cost billions of dollars annually for airlines, passengers, and the US economy. Therefore, this study seeks to find out why the delays occur and to analyze patterns in which the delays occurred. Analysis of airport operations generally falls into a macro or micro perspective. At the macro point of view, very few details are considered, and delays are aggregated at the airport level. Especially, shortfalls in airport capacity and a capacity-demand imbalance are the primary causes of delays in this respect. In the micro perspective, each aircraft is modeled individually, and the causes of delays are reproduced as precisely as possible. Micro reasons for air traffic delays include inclement weather, mechanics problems, operation issues. In this regard, this research proposes a methodology that can efficiently and practically predict macro and micro-level air traffic flow in the terminal area. For a macro-level analysis of delays, artificial neural networks models are proposed to predict the hourly airport capacity. Multi-layer perceptron (MLP), recurrent neural network (RNN), and long short-term memory (LSTM) are trained with historical weather and airport capacity data of Hartsfield-Jackson Atlanta airport (ATL). In the performance evaluation, the models have presented decent predictive performance and successfully predicted the test data as well as the training data. On the other hand, Random Forests and AdaBoost are implemented in the micro-level modeling of the air traffic. The micro-level models trained with on-time flight performance data and corresponding weather data focus on a classification of the individual flight delays. The model provides interpretability and imbalanced data handling while the accuracy is as good as the existing methods. Lastly, the predictive model for individual flight delays is refined using the cost-proportionate rejection sampling (costing) method. Along with the integration of the costing method, general machine learning algorithms have been converted to cost-sensitive classifiers. The cost-sensitive classifiers were able to account for asymmetric misclassification costs without losing their diagnostic functionality as binary classifiers. This study presents a data-driven approach to air…
Advisors/Committee Members: Mavris, Dimitri (advisor), Briceno, Simon (committee member), Schrage, Daniel (committee member), Saletore, Vikram (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Air traffic; Airport capacity; Flight delays; Artificial neural networks; Machine learning; Predictive models
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Choi, S. (2019). A multi-level predictive methodology for terminal area air traffic flow. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61196
Chicago Manual of Style (16th Edition):
Choi, Sun. “A multi-level predictive methodology for terminal area air traffic flow.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/61196.
MLA Handbook (7th Edition):
Choi, Sun. “A multi-level predictive methodology for terminal area air traffic flow.” 2019. Web. 05 Mar 2021.
Vancouver:
Choi S. A multi-level predictive methodology for terminal area air traffic flow. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/61196.
Council of Science Editors:
Choi S. A multi-level predictive methodology for terminal area air traffic flow. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/61196
9.
Wang, Xin.
The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter.
Degree: PhD, Mathematics, 2018, Georgia Tech
URL: http://hdl.handle.net/1853/60286
► In this thesis, we studied the Back and Forth Error Compensation and Correction (BFECC) method for linear hyperbolic PDE systems and nonlinear scalar conservation laws.…
(more)
▼ In this thesis, we studied the Back and Forth Error Compensation and Correction (BFECC) method for linear hyperbolic PDE systems and nonlinear scalar conservation laws. We extend the BFECC method from scalar hyperbolic PDEs to linear
hyperbolic PDE systems, and showed similar stability and accuracy improvement are still valid under modest assumptions on the systems. Motivated by this theoretical result, we propose BFECC schemes for the Maxwell’s equations. On uniform orthogonal grids, the BFECC schemes are guaranteed to be second order accurate and have larger CFL numbers than that of the classical Yee scheme. On non-orthogonal and unstructured grids, we propose to use a simple least square local linear approximation scheme as the underlying scheme for the BFECC method. Numerical results showed the proposed schemes are stable and are second order accurate on non-orthogonal grids and for systems with variable coefficients. We also studied a conservative BFECC limiter
that reduces spurious oscillations for numerical solutions of nonlinear scalar conservation laws. Numerical examples with the Burgers’ equation and KdV equations are studied to demonstrate effectiveness of this limiter.
Advisors/Committee Members: Kang, Sung Ha (committee member), Zhou, Haomin (committee member), Xu, Zhiliang (committee member).
Subjects/Keywords: BFECC; Yee scheme; FDTD
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APA ·
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APA (6th Edition):
Wang, X. (2018). The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60286
Chicago Manual of Style (16th Edition):
Wang, Xin. “The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter.” 2018. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/60286.
MLA Handbook (7th Edition):
Wang, Xin. “The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter.” 2018. Web. 05 Mar 2021.
Vancouver:
Wang X. The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/60286.
Council of Science Editors:
Wang X. The back and forth error compensation and correction method for linear hyperbolic systems and a conservative BFECC limiter. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/60286
10.
Chen, Danjue.
Studies of traffic oscillations: a behavioral perspective.
Degree: PhD, Civil and Environmental Engineering, 2012, Georgia Tech
URL: http://hdl.handle.net/1853/48975
► Traffic oscillations, or simply stop-and-go waves, are a common phenomenon arising in congested traffic but still not well understood. This phenomenon causes broad adverse impacts…
(more)
▼ Traffic oscillations, or simply stop-and-go waves, are a common phenomenon arising in congested traffic but still not well understood. This phenomenon causes broad adverse impacts to safety risk, fuel efficiency and greenhouse emission. To eliminate or reduce those impacts, understanding the cause and propagation mechanism is essential. This dissertation studied driving behavior in traffic oscillations with the objective to uncover the formation and propagation mechanism of traffic oscillations. This study establishes a behavioral car-following model, the Asymmetric Behavioral model, based on empirical trajectory data that is able to reproduce the spontaneous formation and ensuing propagation of traffic oscillations in congested traffic. By analyzing individual drivers' car-following behavior throughout oscillation cycles it is found that this behavior is consistent across drivers and can be captured by a simple model. The statistical analysis of the model's parameters reveals that driver' behavior during oscillation (i.e., reaction to oscillation) is strongly correlated with driver behavior before oscillations and it varies with the development stage of the oscillation. Simulation of the model shows that it is able to produce characteristics of traffic oscillations consistently with empirical observations. This study also unveils the generation mechanism of the traffic hysteresis phenomenon arising in traffic oscillations using the Asymmetric Behavioral model. It is found that the occurrence of traffic hysteresis is closely correlated with driver behavior when experiencing traffic oscillations. In the growth and fully-developed stage of traffic oscillations, drivers behave differently, which results in different distribution of hysteresis patterns. This research makes it possible to unveil new management and control strategies of traffic oscillations to improve traffic operation and to quantify the environmental and safety impacts of traffic oscillations. For example, it can be used to estimate the increase of greenhouse emission and decrease of fuel efficiency imposed by traffic oscillations. It can also be used to study the increase of accident rate.
Advisors/Committee Members: Laval, Jorge (advisor), Guensler, Randall (committee member), Leonard, John (committee member), Rodgers, Michael (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Traffic flow theory; Traffic oscillations; Driving behavior; Traffic hysteresis; Stop-and-go; Traffic flow; Traffic congestion; Traffic patterns
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APA (6th Edition):
Chen, D. (2012). Studies of traffic oscillations: a behavioral perspective. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/48975
Chicago Manual of Style (16th Edition):
Chen, Danjue. “Studies of traffic oscillations: a behavioral perspective.” 2012. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/48975.
MLA Handbook (7th Edition):
Chen, Danjue. “Studies of traffic oscillations: a behavioral perspective.” 2012. Web. 05 Mar 2021.
Vancouver:
Chen D. Studies of traffic oscillations: a behavioral perspective. [Internet] [Doctoral dissertation]. Georgia Tech; 2012. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/48975.
Council of Science Editors:
Chen D. Studies of traffic oscillations: a behavioral perspective. [Doctoral Dissertation]. Georgia Tech; 2012. Available from: http://hdl.handle.net/1853/48975
11.
Luo, Ye.
Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing.
Degree: PhD, Electrical and Computer Engineering, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/52335
► The content in the dissertation is divided into two main categories: (1) micro-particle characterization techniques based on elastic light scattering, and (2) ultra-compact on-chip plasmonic…
(more)
▼ The content in the dissertation is divided into two main categories: (1) micro-particle characterization techniques based on elastic light scattering, and (2) ultra-compact on-chip plasmonic light concentration and its applications. For category (1), I developed two techniques, one is in vitro and the other is in the scenario of flow cytometry. I investigated theoretically and experimentally the spectra of scattered light from spherical dielectric particles at certain fixed angles, and demonstrate the linearity between the peak positions in the Fourier domain and the diameter of the particle. Based on this discovery, I demonstrate an efficient and accurate technique for in-vitro micro-particle sizing. Moreover, I theoretically analyzed the far-field elastic scattering signals from micro-particles passing through a flow cytometer with tightly focused incident beams, and established an algorithm to extract size information from the detected signals with higher accuracy than that in conventional flow cytometry systems. For category (2), I proposed an on-chip plasmonic nanofocusing technique whose unit device is a plasmonic triangle-shaped nanotaper mounted upon a dielectric optical waveguide. This structure provides highly efficient and robust light concentration into the tip of the nanotaper. Near-field measurements were performed to thoroughly investigate a fabricated sample and prove the concept. I also proposed theoretically a novel concept named phase-induced local-field configuration with logic behaviors, whose actuators are composite devices built on units of single on-chip plasmonic light concentrators mentioned above.
Advisors/Committee Members: Adibi, Ali (advisor), Chang, Gee-Kung (committee member), Ralph, Stephen (committee member), Buck, John (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Elastic light scattering; Particle sizing; Flow cytometry; Plasmonic nanofocusing
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APA (6th Edition):
Luo, Y. (2014). Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52335
Chicago Manual of Style (16th Edition):
Luo, Ye. “Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing.” 2014. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/52335.
MLA Handbook (7th Edition):
Luo, Ye. “Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing.” 2014. Web. 05 Mar 2021.
Vancouver:
Luo Y. Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/52335.
Council of Science Editors:
Luo Y. Some optical techniques for characterizing micro-scale particles and on-chip plasmonic nanofocusing. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/52335
12.
Wang, Xiaolin.
A numerical study of vorticity-enhanced heat transfer.
Degree: PhD, Mathematics, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/54017
► In this work, we have numerically studied the effect of the vorticity on the enhancement of heat transfer in a channel flow. In the first…
(more)
▼ In this work, we have numerically studied the effect of the vorticity on the enhancement of heat transfer in a channel flow. In the first part of the work, we focus on the investigation of a channel flow with a vortex street as the incoming flow. We propose a model to simulate the fluid dynamics. We find that the flow exhibits different properties depending on the value of four dimensionless parameters. In particularly, we can classify the flows into two types, active and passive vibration, based on the sign of the incoming vortices. In the second part of the work, we discuss the heat transfer process due to the flows just described and investigate how the vorticity in the flow improves the efficiency of the heat transfer. The temperature shows different characteristics corresponding to the active and passive vibration cases. In active vibration cases, the vortex blob improves the heat transfer by disrupting the thermal boundary layer and preventing the decay of the wall temperature gradient throughout the channel, and by enhancing the forced convection to cool down the wall temperature. The heat transxfer performance is directly related to the strength of the vortex blobs and the background flow. In passive vibration cases, the corresponding heat transfer process is complicated and varies dramatically as the flow changes its properties. We also studied the effect of thermal parameters on heat transfer performance. Finally, we propose a more realistic optimization problem which is to minimize the maximum temperature of the solids with a given input energy. We find that the best heat transfer performance is obtained in the active vibration case with zero background flow.
Advisors/Committee Members: Zhou, Haomin (advisor), Silas, Alben (advisor), Liu, Yingjie (committee member), Chow, Edmond (committee member), Poulson, Jack (committee member).
Subjects/Keywords: Vorticity; Heat transfer; Enhancement
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APA (6th Edition):
Wang, X. (2014). A numerical study of vorticity-enhanced heat transfer. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54017
Chicago Manual of Style (16th Edition):
Wang, Xiaolin. “A numerical study of vorticity-enhanced heat transfer.” 2014. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/54017.
MLA Handbook (7th Edition):
Wang, Xiaolin. “A numerical study of vorticity-enhanced heat transfer.” 2014. Web. 05 Mar 2021.
Vancouver:
Wang X. A numerical study of vorticity-enhanced heat transfer. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/54017.
Council of Science Editors:
Wang X. A numerical study of vorticity-enhanced heat transfer. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54017
13.
Wang, Yichen.
Modeling, predicting, and guiding users' temporal behaviors.
Degree: PhD, Mathematics, 2018, Georgia Tech
URL: http://hdl.handle.net/1853/60208
► The increasing availability and granularity of temporal event data produced from user activities in online media, social networks and health informatics provide new opportunities and…
(more)
▼ The increasing availability and granularity of temporal event data produced from user activities in online media, social networks and health informatics provide new opportunities and challenges to model and understand user behaviors. In addition to studying the macroscopic patterns on the population level, such type of data further enable us to investigate user interactions in a more fine-grained scale to address the "who will do what by when?" question with new exploratory and predictive models. On the other hand, these myriads of microscopic event data, such as publishing a post, forwarding a tweet, purchasing a product, checking in a place, often arise asynchronously and interdependently; hence they require new representing and analyzing methods far beyond those based on independent and identically distributed data models. In this dissertation, I present a novel probabilistic framework for modeling, learning, predicting, and guiding users’ temporal behaviors. Within the proposed framework, we introduce a pipeline of newly developed statistical models, state-of-the-arts learning algorithms to tackle several canonical problems in theory and practice, including: (1) provable nonparametric learning of temporal point processes, (2) a generic embedding framework for continuous-time evolving graphs, (3) scalable algorithms for predicting user activity levels, and (4) a stochastic differential equation framework for guiding users’ activities.
Advisors/Committee Members: Song, Le (advisor), Zha, Hongyuan (committee member), Davenport, Mark (committee member), Ye, Xiaojing (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Point processes; Hawkes processes; Survival analysis; Low-rank models; Mass transport; Fokker Planck equation; Stochastic optimal control; Reinforcement learning; Social network analysis; Information diffusion; Recommendation systems
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APA (6th Edition):
Wang, Y. (2018). Modeling, predicting, and guiding users' temporal behaviors. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60208
Chicago Manual of Style (16th Edition):
Wang, Yichen. “Modeling, predicting, and guiding users' temporal behaviors.” 2018. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/60208.
MLA Handbook (7th Edition):
Wang, Yichen. “Modeling, predicting, and guiding users' temporal behaviors.” 2018. Web. 05 Mar 2021.
Vancouver:
Wang Y. Modeling, predicting, and guiding users' temporal behaviors. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/60208.
Council of Science Editors:
Wang Y. Modeling, predicting, and guiding users' temporal behaviors. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/60208
14.
Ralli, Peter Sharp.
Curvature and isoperimetry in graphs.
Degree: PhD, Mathematics, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/59221
► This dissertation concerns isoperimetric and functional inequalities in discrete spaces. The majority of the work concerns discrete notions of curvature. There is also discussion of…
(more)
▼ This dissertation concerns isoperimetric and functional inequalities in discrete spaces. The majority of the work concerns discrete notions of curvature. There is also discussion of volume growth in graphs and of expansion in hypergraphs.
Advisors/Committee Members: Tetali, Prasad (advisor), Romberg, Justin (committee member), Trotter, William T. (committee member), Yu, Xingxing (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Combinatorics; Graph theory; Discrete geometry
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APA (6th Edition):
Ralli, P. S. (2017). Curvature and isoperimetry in graphs. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59221
Chicago Manual of Style (16th Edition):
Ralli, Peter Sharp. “Curvature and isoperimetry in graphs.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/59221.
MLA Handbook (7th Edition):
Ralli, Peter Sharp. “Curvature and isoperimetry in graphs.” 2017. Web. 05 Mar 2021.
Vancouver:
Ralli PS. Curvature and isoperimetry in graphs. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/59221.
Council of Science Editors:
Ralli PS. Curvature and isoperimetry in graphs. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59221
15.
Kim, Dae Hyun.
Design methodologies for scalable and reliable memory systems.
Degree: PhD, Electrical and Computer Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/58654
► The objective of this research is to develop design methodologies for scalable and reliable memory systems in the presence of scalability and reliability issues exacerbated…
(more)
▼ The objective of this research is to develop design methodologies for scalable and reliable memory systems in the presence of scalability and reliability issues exacerbated or created by continuous scaling. After investigating the origins and device-level mechanisms of memory failures, to examine the impact of such failures on operations of a memory system, this research proposes circuit- and system-level modeling and simulating methodologies. From observations based on simulation results, this research introduces design methodologies that mitigate row-hammering phenomenon by employing counter-based or probabilistic row activations on victim rows and repair increasing wearout failures by exploiting error-correcting codes for the error detection and sequence of commands for error identification during field operations. To enhance the reliability of a memory system, this research proposes methodologies that accurately estimate memory reliability using a system-level accelerated life tests with built-in self-test and error-correcting codes. This research also introduces a method of optimizing the design of experiments for isolating a failure caused by a target wearout mechanism from failures caused by other mechanisms and minimizing errors in the estimation of wearout parameters at the normal operating condition.
Advisors/Committee Members: Milor, Linda (advisor), Chatterjee, Abhijit (committee member), Swaminathan, Madhavan (committee member), Yalamanchili, Sudhakar (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Memory; Scaling; Reliability; System; Circuit; Test; Repair; Design; Error-correcting codes
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APA (6th Edition):
Kim, D. H. (2017). Design methodologies for scalable and reliable memory systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58654
Chicago Manual of Style (16th Edition):
Kim, Dae Hyun. “Design methodologies for scalable and reliable memory systems.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/58654.
MLA Handbook (7th Edition):
Kim, Dae Hyun. “Design methodologies for scalable and reliable memory systems.” 2017. Web. 05 Mar 2021.
Vancouver:
Kim DH. Design methodologies for scalable and reliable memory systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/58654.
Council of Science Editors:
Kim DH. Design methodologies for scalable and reliable memory systems. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/58654
16.
Huang, Shengnan.
Topological defects in confined nematic liquid crystal systems and the transitions between them.
Degree: PhD, Physics, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/61711
► The major theme of this thesis is the treatment of defect cores in uniaxial nematic liquid crystals. For simplicity, we prefer the Oseen-Frank formalism, where…
(more)
▼ The major theme of this thesis is the treatment of defect cores in uniaxial nematic liquid crystals. For simplicity, we prefer the Oseen-Frank formalism, where the orientational order of the uniaxial nematics is represented by unit vectors with head-tail symmetry. However, the defect core in this formalism is a tiny region where the unit vectors are not defined. This implies that when we evaluate the Oseen-Frank free-energy functional and solve the corresponding Euler-Lagrange equation, we should not admit differentiation and integration cross the defect core. In fact, we should either treat the defect core as a boundary or put it at the coordinate singularity of a special coordinate system. The first treatment is used in our numerical study of the defect transitions in the nematic bridges. The finite-difference method (with the use of the successive over-relaxation method) enables us to select the ground state after exhausting many possible defect structures. Our results confirm the existence of different types of equilibrium defect structures in the cylindrical bridge. Our results further imply that some different shapes of the lateral surfaces preserve the qualitative features of the defect structure diagram yet they can change the positions of the transition lines. However, the above-mentioned two treatments impede a general analytical theory of defects in nematics since they usually require exhaustive search or special geometries. Therefore, a better treatment may be to create the defect core during the calculation process. To test its feasibility, we conduct a numerical experiment by designing a special multigrid method for the study of equilibrium defect structures in the cylindrical bridge, where the crudest information of the defect core is expected to be contained on the coarsest grid and better information of the defect core is expected to be contained on the finer grid. Then, for the analytical study, we first experiment on the one-dimensional analog, where the solution is represented by Fourier series and the defect core is the jump discontinuity. We observe that the correct energy function can be obtained by properly eliminating an infinitely large part, and the resulting regularized energy function is equally effective with a finite number of its Fourier modes for the purpose of determining the equilibrium state. Based on that, some calculations are performed for two-dimensional nematics. We speculate that a finite number of Fourier modes of the regularized energy function may be enough to determine the equilibrium defect structures in nematics.
Advisors/Committee Members: Goldbart, Paul M. (advisor), Matsumoto, Elisabetta (committee member), Wiesenfeld, Kurt (committee member), Yunker, Peter (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Topological defects; Nematic liquid crystal; Fourier series
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APA (6th Edition):
Huang, S. (2019). Topological defects in confined nematic liquid crystal systems and the transitions between them. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61711
Chicago Manual of Style (16th Edition):
Huang, Shengnan. “Topological defects in confined nematic liquid crystal systems and the transitions between them.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/61711.
MLA Handbook (7th Edition):
Huang, Shengnan. “Topological defects in confined nematic liquid crystal systems and the transitions between them.” 2019. Web. 05 Mar 2021.
Vancouver:
Huang S. Topological defects in confined nematic liquid crystal systems and the transitions between them. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/61711.
Council of Science Editors:
Huang S. Topological defects in confined nematic liquid crystal systems and the transitions between them. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/61711
17.
Zhai, Haoyan.
The applications of discrete optimal transport in path planning and data clustering.
Degree: PhD, Mathematics, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/61712
► Optimal transport introduces the concept of Wasserstein distance, which has been widely used in various applications in computational mathematics, machine learning as well as many…
(more)
▼ Optimal transport introduces the concept of Wasserstein distance, which has been widely used in various applications in computational mathematics, machine learning as well as many areas in engineering. Meanwhile, control theory and path planning is an active branch in mathematics and robotics, focusing on algorithms that calculate feasible or optimal paths for robotic systems. In this thesis, we use the properties of the gradient flows induced by Wasserstein-2 metric to design algorithms to handle different types of path planning and control problems. Also, we define the Wasserstein K-means problems on graphs and propose an efficient algorithm to solve it. First of all, we provide an algorithm to handle the path planning problem in unknown environments. We develop a deterministic approach with finite-step convergence guarantee. Also, there is a theoretical relation between this algorithm and the Fokker-Planck equations, which bounds the searching region of the algorithm. We use numerical examples to show the efficiency of the algorithm as well as to support the theoretical results. Then, we generalize the algorithm to solve the general control problem in the unknown environments and similar convergence results can be proven. Besides, there is an evidence that the algorithm is guided by the evolution of Fokker-Planck equation, and we use experiments to demonstrate our theorems. We move on to study the optimal path planning in flow field. In this case, the objective function, the traveling time or kinetic energy, is to be minimized with a given flow field. Following the idea of method of evolving junctions, we first transform the original infinite dimensional optimal control into a finite dimensional global optimization problem by introducing junctions located only on the discontinuity positions of the dynamics. To handle the global optimization, intermittent diffusion is used here to guarantee the completeness of the method. At last, we define the discrete Wasserstein-(1,p) distance that depends on the graph structure. With this distance function, we further propose the Wasserstein K-means problem on a general graph and provide an algorithm in the framework of Lloyd method. The key part of the algorithm is the calculation of discrete Wasserstein-(1,p) distance and the gradient flow induced by Wasserstein-2 metric to solve an optimization with objective function being a linear combination of Wasserstein-(1.p) distance. Examples and simulation results are provided in the thesis.
Advisors/Committee Members: Zhou, Haomin (advisor), Dieci, Luca (committee member), Kang, Sung Ha (committee member), Short, Martin (committee member), Zhang, Fumin (committee member).
Subjects/Keywords: Optimal transport; Path planning; Fokker-Planck equation
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APA (6th Edition):
Zhai, H. (2019). The applications of discrete optimal transport in path planning and data clustering. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61712
Chicago Manual of Style (16th Edition):
Zhai, Haoyan. “The applications of discrete optimal transport in path planning and data clustering.” 2019. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/61712.
MLA Handbook (7th Edition):
Zhai, Haoyan. “The applications of discrete optimal transport in path planning and data clustering.” 2019. Web. 05 Mar 2021.
Vancouver:
Zhai H. The applications of discrete optimal transport in path planning and data clustering. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/61712.
Council of Science Editors:
Zhai H. The applications of discrete optimal transport in path planning and data clustering. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/61712
18.
He, Yunlong.
Accelerated algorithms for composite saddle-point problems and applications.
Degree: PhD, Mathematics, 2014, Georgia Tech
URL: http://hdl.handle.net/1853/53069
► This dissertation considers the composite saddle-point (CSP) problem which is motivated by real-world applications in the areas of machine learning and image processing. Two new…
(more)
▼ This dissertation considers the composite saddle-point (CSP) problem which is motivated by real-world applications in the areas of machine learning and image processing. Two new accelerated algorithms for solving composite saddle-point problems are introduced.
Due to the two-block structure of the CSP problem, it can be solved by any algorithm belonging to the block-decomposition hybrid proximal extragradient (BD-HPE) framework. The framework consists of a family of inexact proximal point methods for solving a general two-block structured monotone inclusion problem which, at every iteration, solves two prox sub-inclusions according to a certain relative error criterion. By exploiting the fact that the two prox sub-inclusions in the context of the CSP problem are equivalent to two composite convex programs, the first part of this dissertation proposes a new instance of the BD-HPE framework that approximately solves them using an accelerated gradient method. It is shown that this new instance has better iteration-complexity than the previous ones.
The second part of this dissertation introduces a new algorithm for solving a special class of CSP problems. The new algorithm is a special instance of the hybrid proximal extragradient (HPE) framework in which a Nesterov's accelerated variant is used to approximately solve the prox subproblems. One of the advantages of the this method is that it works for any constant choice of proximal stepsize. Moreover, a suitable choice of the latter stepsize yields a method with the best known (accelerated inner) iteration complexity for the aforementioned class of saddle-point problems.
Experiment results on both synthetic CSP problems and real-world problems show that the two method significantly outperform several state-of-the-art algorithms.
Advisors/Committee Members: Park, Haesun (advisor), Monteiro, Renato D. C. (committee member), Zhou, Haomin (committee member), Kang, Sung Ha (committee member), Song, Le (committee member).
Subjects/Keywords: Saddle-point problem; Composite optimization; Accelerated algorithm; Machine learning; Image processing
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APA ·
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APA (6th Edition):
He, Y. (2014). Accelerated algorithms for composite saddle-point problems and applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53069
Chicago Manual of Style (16th Edition):
He, Yunlong. “Accelerated algorithms for composite saddle-point problems and applications.” 2014. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/53069.
MLA Handbook (7th Edition):
He, Yunlong. “Accelerated algorithms for composite saddle-point problems and applications.” 2014. Web. 05 Mar 2021.
Vancouver:
He Y. Accelerated algorithms for composite saddle-point problems and applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/53069.
Council of Science Editors:
He Y. Accelerated algorithms for composite saddle-point problems and applications. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53069
19.
Tran, Long Quoc.
Efficient inference algorithms for network activities.
Degree: PhD, Computational Science and Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/53499
► The real social network and associated communities are often hidden under the declared friend or group lists in social networks. We usually observe the manifestation…
(more)
▼ The real social network and associated communities are often hidden under the declared friend or group lists in social networks. We usually observe the manifestation of these hidden networks and communities in the form of recurrent and time-stamped individuals' activities in the social network. The inference of relationship between users/nodes or groups of users/nodes could be further complicated when activities are interval-censored, that is, when one only observed the number of activities that occurred in certain time windows. The same phenomenon happens in the online advertisement world where the advertisers often offer a set of advertisement impressions and observe a set of conversions (i.e. product/service adoption). In this case, the advertisers desire to know which advertisements best appeal to the customers and most importantly, their rate of conversions.
Inspired by these challenges, we investigated inference algorithms that efficiently recover user relationships in both cases: time-stamped data and interval-censored data. In case of time-stamped data, we proposed a novel algorithm called NetCodec, which relies on a Hawkes process that models the intertwine relationship between group participation and between-user influence. Using Bayesian variational principle and optimization techniques, NetCodec could infer both group participation and user influence simultaneously with iteration complexity being O((N+I)G), where N is the number of events, I is the number of users, and G is the number of groups. In case of interval-censored data, we proposed a Monte-Carlo EM inference algorithm where we iteratively impute the time-stamped events using a Poisson process that has intensity function approximates the underlying intensity function. We show that that proposed simulated approach delivers better inference performance than baseline methods.
In the advertisement problem, we propose a Click-to-Conversion delay model that uses Hawkes processes to model the advertisement impressions and thinned Poisson processes to model the Click-to-Conversion mechanism. We then derive an efficient Maximum Likelihood Estimator which utilizes the Minorization-Maximization framework. We verify the model against real life online advertisement logs in comparison with recent conversion rate estimation methods.
To facilitate reproducible research, we also developed an open-source software package that focuses on various Hawkes processes proposed in the above mentioned works and prior works. We provided efficient parallel (multi-core) implementations of the inference algorithms using the Bayesian variational inference framework. To further speed up these inference algorithms, we also explored distributed optimization techniques for convex optimization under the distributed data situation. We formulate this problem as a consensus-constrained optimization problem and solve it with the alternating direction method for multipliers (ADMM). It turns out that using bipartite graph as communication topology exhibits the fastest…
Advisors/Committee Members: Chau, Duen Horng (Polo) (advisor), Zha, Hongyuan (committee member), Song, Le (committee member), Sun, Jimeng (committee member), Zhou, Haomin (committee member), Gray, Alexander G. (committee member).
Subjects/Keywords: Hawkes; Inference
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APA (6th Edition):
Tran, L. Q. (2015). Efficient inference algorithms for network activities. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53499
Chicago Manual of Style (16th Edition):
Tran, Long Quoc. “Efficient inference algorithms for network activities.” 2015. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/53499.
MLA Handbook (7th Edition):
Tran, Long Quoc. “Efficient inference algorithms for network activities.” 2015. Web. 05 Mar 2021.
Vancouver:
Tran LQ. Efficient inference algorithms for network activities. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/53499.
Council of Science Editors:
Tran LQ. Efficient inference algorithms for network activities. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/53499
20.
Ghasemi, Farshid.
Multiplexed label-free integrated photonic biosensors.
Degree: PhD, Electrical and Computer Engineering, 2015, Georgia Tech
URL: http://hdl.handle.net/1853/53633
► Optics and photonics enable important technological solutions for critical areas such as health, communications, energy, and manufacturing. Novel nanofabrication techniques, on the other hand, have…
(more)
▼ Optics and photonics enable important technological solutions for critical areas such as health, communications, energy, and manufacturing. Novel nanofabrication techniques, on the other hand, have enabled the realization of ever shirking devices. On-chip photonic micro-resonators, the fabrication of which was made possible in the recent decade thanks to the progress in nanofabrication, provide a sensitive and scalable transduction mechanism that can be used for biochemical sensing applications. The recognition and quantification of biological molecules is of great interest for a wide range of applications from environmental monitoring and hazard detection to early diagnosis of diseases such as cancer and heart failure. A sensitive and scalable biosensor platform based on an optimized array of silicon nitride microring resonators is proposed for multiplexed, rapid, and label-free detection of biomolecules. The miniature dimension of the proposed sensor allows for the realization of handheld detection devices for limited-resource and point-of-care applications. To realize these sensors, the design, fabrication, stabilization, and integration challenges are addressed. Especially, the focus is placed on solving a major problem in using resonancebased integrated photonic sensors (i.e., the insufficiency of wavelength scan accuracy in typical tunable lasers available) by using an interferometric referencing technique for accurate resonance tracking. This technique can improve the limit of detection of the proposed sensor by more than one order of magnitude. The method does not require any temperature control or cooling, and the biosensor platform does not require narrow linewidths necessary for the biosensors based on ultrahigh quality factor resonators, thus enabling low-cost and reliable integration on the biosensor platform.
Advisors/Committee Members: Adibi, Ali (advisor), Ralph, Stephen E. (committee member), Chang, Jee-Kung (committee member), Zhou, Haomin (committee member), Cressler, John (committee member).
Subjects/Keywords: Silicon photonics; Biosensors; Multiplexed sensing
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APA ·
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MLA ·
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APA (6th Edition):
Ghasemi, F. (2015). Multiplexed label-free integrated photonic biosensors. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53633
Chicago Manual of Style (16th Edition):
Ghasemi, Farshid. “Multiplexed label-free integrated photonic biosensors.” 2015. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/53633.
MLA Handbook (7th Edition):
Ghasemi, Farshid. “Multiplexed label-free integrated photonic biosensors.” 2015. Web. 05 Mar 2021.
Vancouver:
Ghasemi F. Multiplexed label-free integrated photonic biosensors. [Internet] [Doctoral dissertation]. Georgia Tech; 2015. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/53633.
Council of Science Editors:
Ghasemi F. Multiplexed label-free integrated photonic biosensors. [Doctoral Dissertation]. Georgia Tech; 2015. Available from: http://hdl.handle.net/1853/53633
21.
Hu, Song.
Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems.
Degree: PhD, Electrical and Computer Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/58267
► Power amplifier (PA) often governs the energy efficiency of a wireless transceiver. Its linearity is also of paramount importance to ensure the signal fidelity. Moreover,…
(more)
▼ Power amplifier (PA) often governs the energy efficiency of a wireless transceiver. Its linearity is also of paramount importance to ensure the signal fidelity. Moreover, its broadband operation is highly desired for high-speed wireless communication. However, integrating a PA in silicon entails challenges due to the PA’s nature of large-signal and highly dynamic operation. This research exploits the mixed-signal computation and novel on-chip electromagnetic networks to enable intelligent RF/millimeter-wave large-signal operation in silicon. This research demonstrates the introduced design methodologies by silicon implementations. In a multiband millimeter-wave PA in silicon, mixed-signal reconfiguration and a novel on-chip power combiner enable broadband operation for fifth-generation (5G) communication. In a digital Doherty PA in silicon, flexible and precise digital control optimizes in-field Doherty efficiency enhancement and enables robustness against antenna mismatch. In addition, this research demonstrates two hybrid PA efficiency enhancement techniques that leverage digital-intensive architectures in silicon. Mixed-signal linearization is introduced in these architectures to eliminate the trade-off between efficiency and linearity.
Advisors/Committee Members: Wang, Hua (advisor), Cressler, John D. (committee member), Ghovanloo, Maysam (committee member), Chang, Gee-Kung (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: 5G; Antenna; BiCMOS; Broadband; CMOS; Digital; Doherty; Efficiency; Electromagnetic; Hybrid; Large signal; Linearity; Millimeter wave; Mixed signal; Multiband; Power amplifier; RF; Silicon; Transmitter; Wireless
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APA (6th Edition):
Hu, S. (2017). Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58267
Chicago Manual of Style (16th Edition):
Hu, Song. “Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/58267.
MLA Handbook (7th Edition):
Hu, Song. “Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems.” 2017. Web. 05 Mar 2021.
Vancouver:
Hu S. Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/58267.
Council of Science Editors:
Hu S. Silicon-based RF/mm-wave power amplifiers and transmitters for future energy-efficient and broadband communication systems. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/58267
22.
Cha, Soonyoung.
Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system.
Degree: PhD, Electrical and Computer Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/59748
► The objective of this research is to extract NBTI and GOBD model parameters to enable the estimation of the degradation and the remaining life of…
(more)
▼ The objective of this research is to extract NBTI and GOBD model parameters to enable the estimation of the degradation and the remaining life of individual chips. Also, the performance degradation can predict lifetime as well, and can enable the optimization of timing guardbands or circuit adaptation based on a prediction of the increase in delay as a function of time, temperature, and usage. Based on the performance degradation analysis, we design a yield and reliability tolerant system by using a self-adaptive clock duty cycle controller (DCC) system to avoid timing violations of critical paths in an integrated circuit.
Advisors/Committee Members: Milor, Linda S. (advisor), Keezer, David C. (committee member), Naeemi, Azad J. (committee member), Bakir, Muhannad S. (committee member), Zhou, Haomin (committee member).
Subjects/Keywords: Design for reliability and yield enhancement; Device-level and system-level reliability modeling
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APA (6th Edition):
Cha, S. (2017). Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59748
Chicago Manual of Style (16th Edition):
Cha, Soonyoung. “Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system.” 2017. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/59748.
MLA Handbook (7th Edition):
Cha, Soonyoung. “Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system.” 2017. Web. 05 Mar 2021.
Vancouver:
Cha S. Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/59748.
Council of Science Editors:
Cha S. Frontend reliability analysis and modeling from device to integrated circuits for reliability and yield enhancement system. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59748
Georgia Tech
23.
Kampel, Guido.
Mathematical Modeling of Fines Migration snd Clogging in Porous Media.
Degree: PhD, Mathematics, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/19764
► Mathematical Modeling of Fines Migration and Clogging in Porous Media Guido Kampel 87 Pages Directed by Dr. Guillermo H. Goldsztein A porous medium is a…
(more)
▼ Mathematical Modeling of Fines Migration and Clogging in Porous Media
Guido Kampel
87 Pages
Directed by Dr. Guillermo H. Goldsztein
A porous medium is a material that contains regions filled with fluid embedded in a solid matrix. These fluid filled regions are called pores or voids. Suspensions are fluids with small particles called fines. As a suspension flows through a porous material, some fines are trapped within the material while others that were trapped may be released.
Filters are an example of porous media. We model filters as networks of channels.
As a suspension flows across the filter, particles clog channels. We assume that there is no flow through clogged channels. In the first part of this thesis, we compute a sharp upper bound on the number of channels that can clog before fluid can no longer flow through the filter.
Soil mass is another example of porous media. Fluid in porous media flows through tortuous paths. This tortuosity and inertial effects cause fines to collide with pore walls.
After each collision, a particle looses momentum and needs to be accelerated again by hydrodynamic forces. As a result, the average velocity of fines is smaller than that of the fluid. This retardation of the fines with respect to the fluid may lead to an increase of the concentration of fines in certain regions which may eventually result in the plugging of the porous medium. This effect is of importance in flows near wells where the flow has circular symmetry and thus, it is not macroscopically homogeneous. In the second part of this thesis we develop and analyze a mathematical model to study the physical effect described above.
In the third and last part of this thesis we study particle migration and clogging as suspension flows through filters by means of numerical simulations and elementary analysis. We explore the effect that network geometry, probability distribution of the width of the channels and probability distribution of the diameter of the particles have on the performance of filters.
Advisors/Committee Members: Goldsztein, Guillermo (Committee Chair), Dieci, Luca (Committee Member), McCuan, John (Committee Member), Santamarina, Juan (Committee Member), Zhou, Haomin (Committee Member).
Subjects/Keywords: Mathematical modeling; Fines migration; Porous media; Clogging; Filters; Porous materials; Suspensions (Chemistry); Particles; Dynamics of a particle; Fluid dynamics; Mathematical models; Filters and filtration
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APA (6th Edition):
Kampel, G. (2007). Mathematical Modeling of Fines Migration snd Clogging in Porous Media. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/19764
Chicago Manual of Style (16th Edition):
Kampel, Guido. “Mathematical Modeling of Fines Migration snd Clogging in Porous Media.” 2007. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/19764.
MLA Handbook (7th Edition):
Kampel, Guido. “Mathematical Modeling of Fines Migration snd Clogging in Porous Media.” 2007. Web. 05 Mar 2021.
Vancouver:
Kampel G. Mathematical Modeling of Fines Migration snd Clogging in Porous Media. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/19764.
Council of Science Editors:
Kampel G. Mathematical Modeling of Fines Migration snd Clogging in Porous Media. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/19764
Georgia Tech
24.
Lu, Yuan.
Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers.
Degree: PhD, Electrical and Computer Engineering, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/14533
► The objective of this work was to design high-speed circuits using silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) and complementary SiGe (C-SiGe) HBTs, as well as…
(more)
▼ The objective of this work was to design high-speed circuits using silicon-germanium
(SiGe) heterojunction bipolar transistors (HBTs) and complementary SiGe (C-SiGe) HBTs, as well as silicon (Si) complementary metal oxide semiconductor (CMOS) devices, for next-generation ultra-wideband (UWB) transceivers. The advantages of using UWB systems over conventional narrowband transceivers include their lower power requirements, higher data rate, more efficient spectrum usage, precise positioning capability, lower complexity, and lower cost. The two major components in a UWB transceiver IC are the radio frequency (RF) circuit and the analog-to-digital converter (ADC). In this work, circuit-level solutions to improve the speed and performance of critical building blocks in both the RF front-end and the ADC are presented. Device-related issues affecting SiGe HBTs for potential applications in UWB systems intended for use in extreme environments will also be investigated. This research envisions to realize various circuit blocks in a UWB transceiver including, a 3-10 GHz UWB low noise amplifiers (LNAs) in both the second (120 GHz) and third (200 GHz) SiGe technologies, an 8-bit 12 GSample/sec SiGe BiCMOS track-and-hold amplifier (THA), and a fifth order elliptic gm-c low-pass filter in C-SiGe HBT technology. This research will also focus on characterizing SiGe HBTs for UWB electronics for operation in extreme environments by investigating the proton radiation effects in the third generation SiGe HBTs.
Advisors/Committee Members: Cressler, John (Committee Chair), Laskar, Joy (Committee Member), Milor, Linda (Committee Member), Papapolymerou, Ioannis (Committee Member), Zhou, Haomin (Committee Member).
Subjects/Keywords: High-speed circuits; HBT; SiGe; Silicon-germanium
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lu, Y. (2007). Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14533
Chicago Manual of Style (16th Edition):
Lu, Yuan. “Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers.” 2007. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/14533.
MLA Handbook (7th Edition):
Lu, Yuan. “Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers.” 2007. Web. 05 Mar 2021.
Vancouver:
Lu Y. Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/14533.
Council of Science Editors:
Lu Y. Design of High-Speed SiGe HBT Circuits
for Wideband Transceivers. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/14533
Georgia Tech
25.
Robie, David Lee.
Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video.
Degree: PhD, Electrical and Computer Engineering, 2005, Georgia Tech
URL: http://hdl.handle.net/1853/7101
► Error Correction and Concealment of Block Based, Motion-Compensated Temporal Prediction, Transform Coded Video David L. Robie 133 Pages Directed by Dr. Russell M. Mersereau The…
(more)
▼ Error Correction and Concealment of Block Based, Motion-Compensated Temporal Prediction, Transform Coded Video
David L. Robie
133 Pages
Directed by Dr. Russell M. Mersereau
The use of the Internet and wireless networks to bring multimedia to the consumer continues to expand. The transmission of these products is always subject to corruption due to errors such as bit errors or lost and ill-timed packets; however, in many cases, such as real time video transmission, retransmission request (ARQ) is not practical. Therefore receivers must be capable of recovering from corrupted data. Errors can be mitigated using forward error correction in the encoder or error concealment techniques in the decoder. This thesis investigates the use of forward error correction (FEC) techniques in the encoder and error concealment in the decoder in block-based, motion-compensated, temporal prediction, transform codecs. It will show improvement over standard FEC applications and improvements in error concealment relative to the Motion Picture Experts Group (MPEG) standard. To this end, this dissertation will describe the following contributions and proofs-of-concept in the area of error concealment and correction in block-based video transmission. A temporal error concealment algorithm which uses motion-compensated macroblocks from previous frames. A spatial error concealment algorithm which uses the Hough transform to detect edges in both foreground and background colors and using directional interpolation or directional filtering to provide improved edge reproduction. A codec which uses data hiding to transmit error correction information. An enhanced codec which builds upon the last by improving the performance of the codec in the error-free environment while maintaining excellent error recovery capabilities. A method to allocate Reed-Solomon (R-S) packet-based forward error correction that will decrease distortion (using a PSNR metric) at the receiver compared to standard FEC techniques. Finally, under the constraints of a constant bit rate, the tradeoff between traditional R-S FEC and alternate forward concealment information (FCI) is evaluated. Each of these developments is compared and contrasted to state of the art techniques and are able to show improvements using widely accepted metrics. The dissertation concludes with a discussion of future work.
Advisors/Committee Members: Mersereau, Russell (Committee Chair), Altunbasak, Yucel (Committee Member), Fekri, Faramarz (Committee Member), Lanterman, Aaron (Committee Member), Zhou, Haomin (Committee Member).
Subjects/Keywords: MPEG-2; Error correction; Error concealment; Rate distortion coding; MPEG2; MPEG; Steganography; Forward correction information; Joint source channel coding
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Robie, D. L. (2005). Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/7101
Chicago Manual of Style (16th Edition):
Robie, David Lee. “Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video.” 2005. Doctoral Dissertation, Georgia Tech. Accessed March 05, 2021.
http://hdl.handle.net/1853/7101.
MLA Handbook (7th Edition):
Robie, David Lee. “Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video.” 2005. Web. 05 Mar 2021.
Vancouver:
Robie DL. Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Mar 05].
Available from: http://hdl.handle.net/1853/7101.
Council of Science Editors:
Robie DL. Error Correction and Concealment of Bock Based, Motion-Compensated Temporal Predition, Transform Coded Video. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/7101
. 
Open Access Theses and Dissertations
