Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering Faculty Research & Creative Works

Discipline
Keyword
Publication Year

Articles 1501 - 1530 of 3518

Full-Text Articles in Engineering

Character-Based Automated Human Perception Quality Assessment In Document Images, Tayo Obafemi-Ajayi, Gady Agam May 2012

Character-Based Automated Human Perception Quality Assessment In Document Images, Tayo Obafemi-Ajayi, Gady Agam

Electrical and Computer Engineering Faculty Research & Creative Works

Large degradations in document images impede their readability and deteriorate the performance of automated document processing systems. Document image quality (IQ) metrics have been defined through optical character recognition (OCR) accuracy. Such metrics, however, do not always correlate with human perception of IQ. When enhancing document images with the goal of improving readability, e.g., in historical documents where OCR performance is low and/or where it is necessary to preserve the original context, it is important to understand human perception of quality. The goal of this paper is to design a system that enables the learning and estimation of human perception …

Go to article

Efficient On-Line Module-Level Wake-Up Scheduling For High Performance Multi-Module Designs, Ming Chao Lee, Yiyu Shi, Yu Guan Chen, Diana Marculescu, Shih Chieh Chang May 2012

Efficient On-Line Module-Level Wake-Up Scheduling For High Performance Multi-Module Designs, Ming Chao Lee, Yiyu Shi, Yu Guan Chen, Diana Marculescu, Shih Chieh Chang

Electrical and Computer Engineering Faculty Research & Creative Works

Power consumption has become the major bottleneck for modern high-performance architectures, which typically contain large numbers of modules. to suppress leakage power, sleep transistors have been extensively used, and wake-up scheduling is needed to determine the wake-up times and order of these sleep transistors. Most existing works on wake-up scheduling are based on sleep transistors and delay buffers in daisy-chains; they work well for the gate-level scheduling within a module when all the gates need to be turned on. Yet, for state-of-the-art designs, the number of modules that need to be turned on and their locations may vary depending on …

Go to article

Scaling Relations And The Role Of Bond-Charge To The Electron Transmission Through Two Coupled Aharonov-Bohm Rings, Cheng-Hsiao Wu, Lam C. Tran, C. A. Cain May 2012

Scaling Relations And The Role Of Bond-Charge To The Electron Transmission Through Two Coupled Aharonov-Bohm Rings, Cheng-Hsiao Wu, Lam C. Tran, C. A. Cain

Electrical and Computer Engineering Faculty Research & Creative Works

Electron transport and the exact scaling relations for two irreducibly coupled Aharonov-Bohm (AB) rings with two external terminals attached are investigated. In coupled AB rings, a center common path exists where the phase of the electron wave function can be modulated by two applied fluxes simultaneously. The two coupled rings can be considered as two coupled atoms where Fermi level crossings exist not only between bonding states but also between bonding and anti-bonding states when the applied flux is varied in one of the two cases studied. We show that when the smallest atomic-sized coupled rings are scaled up any …

Go to article

Capturing The Phantom Of The Power Grid - On The Runtime Adaptive Techniques For Noise Reduction, Tao Wang, Pei Wen Luo, Yu Shih Su, Liang Chia Cheng, Ding Ming Kwai, Yiyu Shi Apr 2012

Capturing The Phantom Of The Power Grid - On The Runtime Adaptive Techniques For Noise Reduction, Tao Wang, Pei Wen Luo, Yu Shih Su, Liang Chia Cheng, Ding Ming Kwai, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Power supply noise has become one of the primary concerns in low power designs. to ensure power integrity, designers need to make sure that voltage droop and bounce do not exceed noise margin in all possible scenarios. Since it is very difficult to capture the exact worst corner among the mist of complex functionalities in modern VLSI designs, statistical design methodologies have been adapted, which may bring significant design overhead. in view of this, various runtime techniques have been proposed in literature to suppress power grid noise adaptively. This paper first presents various challenges in power grid designs from an …

Go to article

Pricing And Control In The Next Generation Power Distribution System, Gerald Thomas Heydt, Badrul H. Chowdhury, Mariesa Crow, Daniel Haughton, Brian D. Kiefer, Fanjun Meng, Bharadwaj R. Sathyanarayana Apr 2012

Pricing And Control In The Next Generation Power Distribution System, Gerald Thomas Heydt, Badrul H. Chowdhury, Mariesa Crow, Daniel Haughton, Brian D. Kiefer, Fanjun Meng, Bharadwaj R. Sathyanarayana

Electrical and Computer Engineering Faculty Research & Creative Works

Smart grid technologies are gaining acceptance and are being integrated into power distribution systems as a result of public and private investment and funding. However, costs of these technologies appear to be a clear obstacle in the widespread integration and maximal use of these technologies. in this paper, the utilization of dollar pricing signals is proposed and illustrated for power distribution engineering. a signal modeled after locational marginal pricing from transmission engineering is proposed to provide pricing data locally in distribution systems. the calculation, utilization, advantages, and shortcomings of the concept are presented. a main conclusion is that the use …

Go to article

Characterization Of Via Structures In Multilayer Printed Circuit Boards With An Equivalent Transmission-Line Model, Siming Pan, Jun Fan Apr 2012

Characterization Of Via Structures In Multilayer Printed Circuit Boards With An Equivalent Transmission-Line Model, Siming Pan, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Vias are typical discontinuities for high-speed signal transmission in printed circuit boards (PCBs). This paper proposes an equivalent multiconductor transmission-line model for via structures in multilayer PCBs. the proposed model is based on the physic-Based circuit model, taking into account distributed effects. Various via structures with arbitrary via number, trace connections, and via stubs can be effectively handled in the equivalent transmission-line model, which is sufficiently accurate and fast to be integrated into circuit simulators for via and link-path analysis. with the proposed model, well-known transmission-line theories can be borrowed for via modeling and characterization for signal integrity in high-speed …

Go to article

Optimized Power Allocation For Packet Retransmissions Of Non-Gaussian Inputs Through Sequential Awgn Channels, Xiao Liang, Zhi Ding, Chengshan Xiao Apr 2012

Optimized Power Allocation For Packet Retransmissions Of Non-Gaussian Inputs Through Sequential Awgn Channels, Xiao Liang, Zhi Ding, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

This work investigates the optimization of power allocation for hybrid-ARQ (H-ARQ) retransmissions of non-Gaussian inputs over a bank of independent parallel Gaussian channels. We establish a general solution for maximizing generic transceiver objective utility functions that are monotonically non-decreasing and concave function with respect to the accumulated signal to noise ratio (SNR). Specifically, we investigate optimized solutions under two performance metrics, namely, the mutual information (MI) and the union bound of symbol error rate (UBSER) under maximal ratio combining (MRC) reception. We establish that efficient utilization of parallel channels in H-ARQ retransmissions requires sequential updating of signal-channel pairing as well …

Go to article

Spiking Neuron Computation With The Time Machine, Vaibhav Garg, Ravi Shekhar, John G. Harris Apr 2012

Spiking Neuron Computation With The Time Machine, Vaibhav Garg, Ravi Shekhar, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

The Time Machine (TM) is a spike-based computation architecture that represents synaptic weights in time. This choice of weight representation allows the use of virtual synapses, providing an excellent tradeoff in terms of flexibility, arbitrary weight connections and hardware usage compared to dedicated synapse architectures. The TM supports an arbitrary number of synapses and is limited only by the number of simultaneously active synapses to each neuron. SpikeSim, a behavioral hardware simulator for the architecture, is described along with example algorithms for edge detection and objection recognition. The TM can implement traditional spike-based processing as well as recently developed time …

Go to article

An Improved Multiple Scattering Method For Via Structures With Axially Isotropic Modes In An Irregular Plate Pair, Yaojiang Zhang, Arun Reddy Chada, Jun Fan Apr 2012

An Improved Multiple Scattering Method For Via Structures With Axially Isotropic Modes In An Irregular Plate Pair, Yaojiang Zhang, Arun Reddy Chada, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

An improved multiple scattering method is developed for an irregular plate pair where via pad/antipad radius is electrically small and the spacing between any two vias is relatively large so that the axially anisotropic parallel plate modes can be neglected. the plate-pair impedance matrix, widely used as an important parameter in power integrity analysis and also a critical part for via coupling in the intrinsic and the physics-Based via models, is found to be related to the addition theorems of the zero-order axially isotropic propagating modes. as the impedance matrix of an irregular plate pair can be calculated by many …

Go to article

Analytical Prediction Of Crosstalk Among Vias In Multilayer Printed Circuit Boards, Songping Wu, Jun Fan Apr 2012

Analytical Prediction Of Crosstalk Among Vias In Multilayer Printed Circuit Boards, Songping Wu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Crosstalk among vias is a significant problem in high-speed multilayer printed circuit boards (PCBs), deteriorating signal quality and increasing jitter, especially when circuit density is high. in this paper, a two-step via crosstalk evaluation procedure is proposed. a fast approach for crosstalk estimation is developed for net screening as the first step. Then, more accurate but more time-consuming modeling can be performed for critical nets or the problematic nets identified in the screening. the main contribution of this study includes the analytical prediction of crosstalk among vias based on an infinite parallel-plane assumption. its effectiveness and efficiency to predict the …

Go to article

Resonance Scanning System And Method For Testing Equipment For Electromagnetic Resonances, David Pommerenke, Wei Huang, Peng Shao, Jiang Xiao Mar 2012

Resonance Scanning System And Method For Testing Equipment For Electromagnetic Resonances, David Pommerenke, Wei Huang, Peng Shao, Jiang Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A resonance scanning system and method for testing equipment for electromagnetic resonances uses a resonance detection subsystem with at least one probe to identify at least one of a resonating location, a resonating frequency and a quality factor of a resonance of the equipment and an automatic scanning subsystem to displace the probe to different testing locations of the equipment so that the resonance detection subsystem can determine if any of the different testing locations of the equipment exhibits electromagnetic resonances.

Go to article

Resource Scheduling Under Uncertainty In A Smart Grid With Renewables And Plug-In Vehicles, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy Mar 2012

Resource Scheduling Under Uncertainty In A Smart Grid With Renewables And Plug-In Vehicles, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The power system and transportation sector are our planet's main sources of greenhouse gas emissions. Renewable energy sources (RESs), mainly wind and solar, can reduce emissions from the electric energy sector; however, they are very intermittent. Likewise, next generation plug-in vehicles, which include plug-in hybrid electric vehicles and electric vehicles with vehicletogrid capability, referred to as grid able vehicles (GVs) by the authors, can reduce emissions from the transportation sector. GVs can be used as loads, energy sources (small portable power plants) and energy storage units in a smart grid integrated with renewable energy sources. However, uncertainty surrounds the controllability …

Go to article

Linear Precoding For Relay Networks: A Perspective On Finite-Alphabet Inputs, Weiliang Zeng, Yahong Rosa Zheng, Mingxi Wang, Jianhua Lu Mar 2012

Linear Precoding For Relay Networks: A Perspective On Finite-Alphabet Inputs, Weiliang Zeng, Yahong Rosa Zheng, Mingxi Wang, Jianhua Lu

Electrical and Computer Engineering Faculty Research & Creative Works

This paper considers the precoder design for dual-hop amplify-and-forward relay networks and formulates the design from the standpoint of finite-alphabet inputs. in particular, the mutual information is employed as the utility function, which, however, results in a nonlinear and nonconcave problem. This paper exploits the structure of the optimal precoder that maximizes the mutual information and develops a two-step algorithm based on convex optimization and optimization on the Stiefel manifold. by doing so, the proposed algorithm is insensitive to initial point selection and able to achieve a near global optimal precoder solution. Besides, it converges fast and offers high mutual …

Go to article

Finite-Element-Based Generalized Impedance Boundary Condition For Modeling Plasmonic Nanostructures, Shiquan He, Wei E.I. Sha, Lijun Jiang, Wallace C.H. Choy, Weng Cho Chew, Zaiping Nie Mar 2012

Finite-Element-Based Generalized Impedance Boundary Condition For Modeling Plasmonic Nanostructures, Shiquan He, Wei E.I. Sha, Lijun Jiang, Wallace C.H. Choy, Weng Cho Chew, Zaiping Nie

Electrical and Computer Engineering Faculty Research & Creative Works

The superior ability of plasmonic structures to manipulate light has propelled their extensive applications in nanophotonics techniques and devices. Computational electromagnetics plays a critical role in characterizing and optimizing the nanometallic structures. In this paper, a general numerical algorithm, which is different from the commonly used discrete dipole approximation, the finite-difference time-domain, and the surface integral equation (SIE) method, is proposed to model plasmonic nanostructures. In this algorithm, the generalized impedance boundary condition (GIBC) based on the finite element method (FEM) is formulated and converted to the SIE. The plasmonic nanostructures with arbitrary inhomogeneity and shapes are modeled by the …

Go to article

Interpolation-Based Parameterized Model Order Reduction Of Delayed Systems, Francesco Ferranti, Michel Nakhla, Giulio Antonini, Tom Dhaene, Luc Knockaert, Albert E. Ruehli Mar 2012

Interpolation-Based Parameterized Model Order Reduction Of Delayed Systems, Francesco Ferranti, Michel Nakhla, Giulio Antonini, Tom Dhaene, Luc Knockaert, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Three-dimensional electromagnetic methods are fundamental tools for the analysis and design of high-speed systems. These methods often generate large systems of equations, and model order reduction (MOR) methods are used to reduce such a high complexity. When the geometric dimensions become electrically large or signal waveform rise times decrease, time delays must be included in the modeling. Design space optimization and exploration are usually performed during a typical design process that consequently requires repeated simulations for different design parameter values. Efficient performing of these design activities calls for parameterized model order reduction (PMOR) methods, which are able to reduce large …

Go to article

A Low-Complexity Design Of Linear Precoding For Mimo Channels With Finite-Alphabet Inputs, Weiliang Zeng, Chengshan Xiao, Jianhua Lu Feb 2012

A Low-Complexity Design Of Linear Precoding For Mimo Channels With Finite-Alphabet Inputs, Weiliang Zeng, Chengshan Xiao, Jianhua Lu

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates linear precoding scheme that maximizes mutual information for multiple-input multiple-output (MIMO) channels with finite-alphabet inputs. in contrast with recent studies, optimizing mutual information directly with extensive computational burden, this work proposes a low-complexity and high-performance design. It derives a lower bound that demands low computational effort and approximates, with a constant shift, the mutual information for various settings. based on this bound, the precoding problem is solved efficiently. Numerical examples show the efficacy of this method for constant and fading MIMO channels. Compared to its conventional counterparts, the proposed method reduces the computational complexity without performance loss. …

Go to article

Efficient Simulation And Analysis Of Quantum Ballistic Transport In Nanodevices With Awe, Jun Z. Huang, Weng Cho Chew, Min Tang, Lijun Jiang Feb 2012

Efficient Simulation And Analysis Of Quantum Ballistic Transport In Nanodevices With Awe, Jun Z. Huang, Weng Cho Chew, Min Tang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Quantum-mechanical modeling of ballistic transport in nanodevices usually requires solving the Schrdinger equation at multiple energy points within an energy band. To speed up the simulation and analysis, the asymptotic waveform evaluation is introduced in this paper. Using this method, the wave function is only rigorously solved at several sampled energy points, whereas those at other energies are computed through Pad approximation. This allows us to obtain the physical quantities over the whole energy band with very little computational cost. In addition, the accuracy is controllable by a complex frequency hopping algorithm. The validity and efficiency of the proposed method …

Go to article

Compact Electronic Mode Stirred Chamber, Q. Dai, W. C. Chew, Lijun Jiang, B. Zhu Jan 2012

Compact Electronic Mode Stirred Chamber, Q. Dai, W. C. Chew, Lijun Jiang, B. Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

A method and apparatus provide an improved EM reverberation chamber which facilitates the dynamic three-dimensional (3D) manipulation of EM field polarization within the chamber and produces a uniform field distribution inside the chamber. The chamber includes one or more walls with tunable lumped elements. A controller is provided to generate one or more control signals that are applied to the lumped elements and tunes their impedance in response to the one or more control signals. The result is to generate, within the chamber an electromagnetic field that appears to be random or pseudo-random in polarization, but which is sufficiently uniform …

Go to article

Worst-Case Estimation For Data-Dependent Timing Jitter And Amplitude Noise In High-Speed Differential Link, Wei Yao, Yiyu Shi, Lei He, Sudhakar Pamarti Jan 2012

Worst-Case Estimation For Data-Dependent Timing Jitter And Amplitude Noise In High-Speed Differential Link, Wei Yao, Yiyu Shi, Lei He, Sudhakar Pamarti

Electrical and Computer Engineering Faculty Research & Creative Works

Differential signaling has been widely used in high-speed interconnects. Signal integrity issues, such as inter-symbol interference (ISI) and crosstalk between the differential pair, however, still cause significant timing jitter and amplitude noise and heavily limit the performance of the differential link. the pre-emphasis filter is commonly used to reduce ISI but may potentially change the crosstalk behavior. in this paper, we first propose formula-Based jitter and noise models considering the combined effect of ISI, crosstalk, and pre-emphasis filter. with the same set of input patterns, experiment shows our models achieve within 5% difference compared with SPICE simulation. by utilizing these …

Go to article

Graphical Image Classification Combining An Evolutionary Algorithm And Binary Particle Swarm Optimization, Beibei Cheng, Renzhong Wang, Sameer K. Antani, R. Joe Stanley, George R. Thoma Jan 2012

Graphical Image Classification Combining An Evolutionary Algorithm And Binary Particle Swarm Optimization, Beibei Cheng, Renzhong Wang, Sameer K. Antani, R. Joe Stanley, George R. Thoma

Electrical and Computer Engineering Faculty Research & Creative Works

Biomedical journal articles contain a variety of image types that can be broadly classified into two categories: regular images, and graphical images. Graphical images can be further classified into four classes: diagrams, statistical figures, flow charts, and tables. Automatic figure type identification is an important step toward improved multimodal (text + image) information retrieval and clinical decision support applications. This paper describes a feature-based learning approach to automatically identify these four graphical figure types. We apply Evolutionary Algorithm (EA), Binary Particle Swarm Optimization (BPSO) and a hybrid of EA and BPSO (EABPSO) methods to select an optimal subset of extracted …

Go to article

Protocols For Highly-Dynamic Airborne Networks, Egemen K. Çetinkaya, Justin P. Rohrer, Abdul Jabbar, Mohammed J. F. Alenazi, Dongsheng Zhang, Dan S. Broyles, Kamakshi Sirisha Pathapati, Hemanth Narra, Kevin Peters, Santosh Ajith Gogi, James P. G. Sterbenz Jan 2012

Protocols For Highly-Dynamic Airborne Networks, Egemen K. Çetinkaya, Justin P. Rohrer, Abdul Jabbar, Mohammed J. F. Alenazi, Dongsheng Zhang, Dan S. Broyles, Kamakshi Sirisha Pathapati, Hemanth Narra, Kevin Peters, Santosh Ajith Gogi, James P. G. Sterbenz

Electrical and Computer Engineering Faculty Research & Creative Works

End-to-end communication in highly-dynamic airborne networks is challenging due to the presence of highly mobile nodes and the inherent nature of wireless communication channels. Domain-specific protocols are required that can address these challenges and enable reliable transmission of data in this environment. We develop the ANTP (airborne network and transport protocols) suite that operates in this highly-dynamic environment while utilising cross-layer optimisations between the physical, MAC, network, and transport layers. We show how each component in the ANTP suite outperforms the traditional TCP/IP and MANET protocols through simulation using ns-3. Having verified these protocols through simulation and analysis, the next …

Go to article

The Far Field Transformation For The Antenna Modeling Based On Spherical Electric Field Measurements, P. Li, Lijun Jiang Jan 2012

The Far Field Transformation For The Antenna Modeling Based On Spherical Electric Field Measurements, P. Li, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

According to the uniqueness theorem, the far field radiation pattern of radiators such as antennas can be determined from the measured tangential electric or magnetic field components over an arbitrary Huygens' surface enclosing the radiator. In this paper, a method using the spherical electric field measurement is developed to calculate the far field radiation. Following the Schelkunoff's field equivalence principle, a spherical region surrounding the radiator is assumed and its internal space is filled up with the perfect electric conductor (PEC). The radiated field from the Huygens' equivalent electric current is zero. Referring to the Ohm-Rayleigh method and the scattering …

Go to article

An Efficient Method For Computing Highly Oscillatory Physical Optics Integral, Y. M. Wu, Lijun Jiang, W. C. Chew Jan 2012

An Efficient Method For Computing Highly Oscillatory Physical Optics Integral, Y. M. Wu, Lijun Jiang, W. C. Chew

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we use the numerical steepest descent path (numerical SDP) method in complex analysis theory to calculate the highly oscillatory physical optics (PO) integral with quadratic phase and amplitude variations on the triangular patch. The Stokes' phenomenon will occur due to various asymptotic behaviors on different domains. The stationary phase point contributions are carefully studied by the numerical SDP method and complex analysis using contour deformation. Its result agrees very well with the leading terms of the traditional asymptotic expansion. Furthermore, the resonance points and vertex points contributions from the PO integral are also extracted. Compared with traditional …

Go to article

Optimization In Energy And Power Management For Renewable-Diesel Microgrids Using Dynamic Programming Algorithm, Tu A. Nguyen, Mariesa L. Crow Jan 2012

Optimization In Energy And Power Management For Renewable-Diesel Microgrids Using Dynamic Programming Algorithm, Tu A. Nguyen, Mariesa L. Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents an optimization analysis for energy and power management in microgrids with renewable energy resources and diesel generators. Dynamic Programming (DP) algorithm and the simplex method have been used to minimize the total daily cost of the system and also maximize the total efficiency of the energy storage system during charge and discharge. the algorithm is validated on a hybrid system for military forward operating base camps that contain a PV array, wind generator, hydrogen-Based fuel cell, batteries and diesel generators. © 2012 IEEE.

Go to article

A Modified Fixed Sphere Decoding Algorithm For Under-Determined Mimo Systems, Chen Qian, Jingxian Wu, Yahong Rosa Zheng, Zhaocheng Wang Jan 2012

A Modified Fixed Sphere Decoding Algorithm For Under-Determined Mimo Systems, Chen Qian, Jingxian Wu, Yahong Rosa Zheng, Zhaocheng Wang

Electrical and Computer Engineering Faculty Research & Creative Works

A modified FSD algorithm is proposed for under-determined (UD) multiple-input multiple-output (MIMO) systems with N transmit antennas and M < N receive antennas. This paper focuses on the low-complexity detection of coded UD-MIMO systems with iterative turbo detection, where a soft-input soft-output (SISO) MIMO detector exchanges soft information with a SISO decoder. in the first iteration, a modified fixed complexity sphere decoding (FSD) method is developed by utilizing the structure of a UD-MIMO system. the modified FSD employs a new detection ordering scheme that has a lower complexity but a better performance compared to the conventional ordering scheme. from the second iteration and beyond, the MIMO detector is implemented with a generalized serial interference cancelation (GSIC) scheme and a block decision feedback equalizer (BDFE) to further reduce the complexity. Simulation results show that the newly proposed FSD-GSIC-BDFE structure can achieve significant performance gains over existing schemes, especially for systems with high level modulations. © 2012 IEEE.

Go to article

Cross-Layer Design Of Energy Efficient Coded Arq Systems, Gang Wang, Jingxian Wu, Yahong Zheng Jan 2012

Cross-Layer Design Of Energy Efficient Coded Arq Systems, Gang Wang, Jingxian Wu, Yahong Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

The energy efficient design of coded automatic-repeat-request (ARQ) systems is studied in this paper. the optimization aims to minimize the energy required for the successfully delivery of one information bit from a transmitter to a receiver. the design is performed by incorporating a wide range of practical system parameters and metrics, such as hardware power consumption, modulation, channel coding, and frame error rate (FER) in the physical layer, and frame length and protocol overhead in the media access control layer. a new log-domain threshold approximation method is proposed to analytically quantify the impacts of the various system parameters on the …

Go to article

Optimal Adaptive Control Of Nonlinear Continuous-Time Systems In Strict Feedback Form With Unknown Internal Dynamics, H. Zargarzadeh, T. Dierks, S. Jagannathan Jan 2012

Optimal Adaptive Control Of Nonlinear Continuous-Time Systems In Strict Feedback Form With Unknown Internal Dynamics, H. Zargarzadeh, T. Dierks, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel approach is proposed for multi-input multi-output (MIMO) optimal adaptive control of nonlinear continuous-time systems in strict feedback form with uncertain internal dynamics. First, it is shown that the optimal adaptive tracking problem of strict feedback systems can be reduced to an optimal regulation problem of affine nonlinear continuous-time systems expressed as a function of tracking error by designing a properly chosen adaptive feedforward control input. Then, an optimal adaptive feedback scheme is introduced for the affine system to estimate the solution of the Hamilton-Jacobi-Bellman (HJB) equation online which becomes the optimal feedback control input for the closed-loop system. …

Go to article

Resilience Of Backbone Provider Networks, Egemen K. Çetinkaya, Justin P. Rohrer, James P. G. Sterbenz Jan 2012

Resilience Of Backbone Provider Networks, Egemen K. Çetinkaya, Justin P. Rohrer, James P. G. Sterbenz

Electrical and Computer Engineering Faculty Research & Creative Works

Network topology models have drawn tremendous interest from the research community. Traditionally, Internet modelling has been done at the AS or router level, in part because this information is most available from tomography and public databases such as Rocketfuel. We argue that physical topology analysis is important for a more complete understanding of Internet structure, particularly for insight into the resilience and survivability of infrastructure against attacks and natural disasters. However, complexity and lack of complete data sets has hindered accurate topology modelling. In this short paper, we show through a sample case that physical topologies have significantly different characteristics …

Go to article

Video Surveillance Analysis As A Context For Embedded Systems And Artificial Intelligence Education, Steve Eugene Watkins Jan 2012

Video Surveillance Analysis As A Context For Embedded Systems And Artificial Intelligence Education, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

Video surveillance analysis is an exciting, active research area and an important industry application. It is a multidisciplinary field that draws on signal processing, embedded systems, and artificial intelligence topics, and is well suited to motivate student engagement in all of these areas. This paper describes the benefits of the convergence of these topics, presents a versatile video surveillance analysis process that can be used as the basis for many investigations, and presents two template exercises in tracking detected targets and in evaluating runtime efficiency. The processing chain consists of detecting changes in a scene and locating and characterizing the …

Go to article

A Self-Tuning Optimal Controller For Affine Nonlinear Continuous-Time Systems With Unknown Internal Dynamics, Travis Dierks, Sarangapani Jagannathan Jan 2012

A Self-Tuning Optimal Controller For Affine Nonlinear Continuous-Time Systems With Unknown Internal Dynamics, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel neural network (NN) - based self-tuning controller for the optimal regulation of affine nonlinear continuous-time systems. Knowledge of the internal system dynamics is not required whereas the control coefficient matrix is considered to be available. the proposed nonlinear optimal regulator tunes itself in order to simultaneously learn the optimal control input, optimal cost function, and the system internal dynamics using a single NN. a novel NN weight tuning algorithm is derived which ensures the internal system dynamics are learned while simultaneously minimizing a predefined cost function. an initial stabilizing controller is not required. Lyapunov methods …

Go to article

First Prev Next Last