Computer Engineering Commons^™

Optimal Bidding Strategy Of A Strategic Wind Power Producer In The Short-Term Market, Ting Dai, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Wind energy is a clean and renewable energy source which is rapidly growing globally. As the penetration level of wind power grows, the system operators need to consider wind power producers as strategic producers whose bidding behaviors will have an impact on the locational marginal prices. This paper proposes a bilevel stochastic optimization model to obtain the optimal bidding strategy for a strategic wind power producer in the short-term electricity market. The upper level problem of the model maximizes the profit of the wind power producer, while the lower level problem represents the market clearing processes of both day-ahead and …

Multiobjective Optimization Of Switched Reluctance Motors Based On Design Of Experiments And Particle Swarm Optimization, Cong Ma, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a comprehensive framework for multiobjective design optimization of switched reluctance motors (SRMs) based on a combination of the design of experiments and particle swarm optimization (PSO) approaches. First, the definitive screening design was employed to perform sensitivity analyses to identify significant design variables without bias of interaction effects between design variables. Next, optimal third-order response surface (RS) models were constructed based on the Audze–Eglais Latin hypercube design using the selected significant design variables. The constructed optimal RS models consist of only significant regression terms, which were selected by using PSO. Then, a PSO-based multiobjective optimization coupled with …

A Survey On Wind Turbine Condition Monitoring And Fault Diagnosis−Part I: Components And Subsystems, Deli Qiao, Dingguo Lu

Department of Electrical and Computer Engineering: Faculty Publications

This paper provides a comprehensive survey on the state-of-the-art condition monitoring and fault diagnostic technologies for wind turbines. The Part I of this survey briefly reviews the existing literature surveys on the subject, discusses the common failure modes in the major wind turbine components and subsystems, briefly reviews the condition monitoring and fault diagnostic techniques for these components and subsystems, and specifically discusses the issues of condition monitoring and fault diagnosis for offshore wind turbines.

A Survey On Wind Turbine Condition Monitoring And Fault Diagnosis−Part Ii: Signals And Signal Processing Methods, Wei Qiao, Dingguo Lu

Department of Electrical and Computer Engineering: Faculty Publications

This paper provides a comprehensive survey on the state-of-the-art condition monitoring and fault diagnostic technologies for wind turbines. The Part II of this survey focuses on the signals and signal processing methods used for wind turbine condition monitoring and fault diagnosis.

A Real-Time Information Based Demand-Side Management System In Smart Grid, Feng Ye, Yi Qian, Rose Qingyang Hu

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we study a real-time information based demand-side management (DSM) system with advanced communication networks in smart grid. DSM can smooth peakto- average ratio (PAR) of power usage in the grid, which in turn reduces the waste of fuel and the emission of greenhouse gas. We first target to minimize PAR with a centralized scheme. To motivate power suppliers, we further propose another centralized scheme targeting minimum power generation cost. However, customers may not be motivated by a centralized scheme since such a scheme requires total control and privacy from them. A centralized scheme also requires too much …

An Isolated Three-Port Bidirectional Dc-Dc Converter For Photovoltaic Systems With Energy Storage, Jianwu Zeng, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a new isolated, three-port, bidirectional, DC-DC converter for simultaneous power management of multiple energy sources. The proposed converter has the advantage of using the least number of switches and soft switching for the main switch, which is realized by using a LCL-resonant circuit. The converter is capable of interfacing sources of different voltage-current characteristics with a load and/or a DC microgrid. The proposed converter is constructed for simultaneous power management of a photovoltaic (PV) panel, a rechargeable battery, and a load. Simulation and experimental results show that the proposed converter is capable of maximum power point tracking …

Modeling And Control Of A Three-Port Dc-Dc Converter For Pv-Battery Systems, Jianwu Zeng, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

This paper presents modeling and decoupled control design for an isolated three-port DC-DC converter (TPC), which interfaces a photovoltaic (PV) panel, a rechargeable battery, and an isolated load. A small signal model is derived from the state-space equations of the TPC. Based on the model, two decoupled controllers are designed to control the power flows of the two sources and the load voltage independently. Experimental studies are performed to verify that the two controllers are capable of regulating the power flows of the PV panel and the battery while maintaining a constant output voltage for the TPC.

Optimal Joint Transmission And Harvested Energy Scheduling For Renewable Energy Harvesting Enabled Cellular Network Under Coordinated Multi-Point Transmission, Zejue Wang, Hongjia Li, Dan Hu, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications

On-grid energy consumption of base stations (BSs) contributes up a significant fraction of the total carbon dioxide (CO₂) emissions of cellular networks, among which remote radio units (RRUs) absorb most of the energy consumption. To eliminate the on-grid energy consumption and the corresponding CO₂ emission, we propose a new transmission framework, in which all RRUs and associated power amplifiers (PAs) are powered by hybrid energy sources including on-grid energy source and off-grid renewable energy source. Based on the framework, we pursue a systematic study on the joint transmission and harvested energy scheduling algorithm for the hybrid energy …

Cmi Analysis And Precoding Designs For Correlated Multi-Hop Mimo Channels, Nguyen N. Tran, Song Ci, Ha X. Nguyen

Department of Electrical and Computer Engineering: Faculty Publications

Conditional mutual information (CMI) analysis and precoding design for generally correlated wireless multi-hop multi-input multi-output (MIMO) channels are presented in this paper. Although some particular scenarios have been examined in existing publications, this paper investigates a generally correlated transmission system having spatially correlated channel, mutually correlated source symbols, and additive colored Gaussian noise (ACGN). First, without precoding techniques, we derive the optimized source symbol covariances upon mutual information maximization. Secondly, we apply a precoding technique and then design the precoder in two cases: maximizing the mutual information and minimizing the detection error. Since the optimal design for the end-to-end system …

Integral Equation Analysis Of Em Scattering From Multilayered Metallic Photonic Crystal Accelerated With Adaptive Cross Approximation, Jianxun Su, Zengrui Li, Xujin Yuan, Yaoqing (Lamar) Yang, Junhong Wang

Department of Electrical and Computer Engineering: Faculty Publications

A space-domain integral equation method accelerated with adaptive cross approximation (ACA) is presented for the fast and accurate analysis of electromagnetic (EM) scattering from multilayered metallic photonic crystal (MPC). The method directly solves for the electric field in order to easily enable the periodic boundary condition (PBC) in the spatial domain. The ACA is a purely algebraic method allowing the compression of fully populated matrices; hence, its formulation and implementation are independent of integral equation kernel (Green’s function).Therefore, the ACA is very well suited for accelerating integral equation analysis of periodic structure with the integral kernel of the periodic Green’s …

Drive Systems Including Sliding Mode Observers And Methods Of Controlling The Same, Long Wu, Yue Zhao, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a Voltage command for the motor, a sliding mode observer configured to determine an estimated current for the motor based on the Voltage command, determine a difference between the measured current and the estimated current, and determine a Switching control vector and an estimator con figured to estimate a rotor position based on the Switching control vector, the Switching control vector being determined based on the difference and adaptive parameters of the …

Probes For Multidimensional Nanospectroscopic Imaging And Methods Of Fabrication Thereof, Alexander Weber-Bargionii, Stefano Cabrini, Wei Bao, Mauro Melli, Eli Yablonovitch, Peter J. Schuck

Department of Electrical and Computer Engineering: Faculty Publications

This disclosure provides systems, methods, and apparatus related to probes for multidimenisonal nanospectroscopic imaging. In one aspect, a method includes providing a transparent tip comprising a dielectric material. A four-sided pyramidal-shaped structure is formed at an apex of the transparent tip using a focus ion beam. Metal layers are deposited over two opposing sides of the four-sided pyramidal-shaped structure.

Coordinated Control And Estimation Of Multiagent Systems With Engineering Applications, Housheng Su, Michael Z.Q. Chen, Qing Hui, Wei Zhang, Fanglai Zhu

Department of Electrical and Computer Engineering: Faculty Publications

Recently, coordinated control and estimation problems have attracted a great deal of attention in different fields especially in biology, physics, computer science, and control engineering. Coordinated control and estimation problems have prominent characteristics of distributed control, local interaction, and self-organization. Research on multiagent coordinated control and estimation problems not only helps better understand the mechanisms of natural collective phenomena but also benefits the applications of cyberphysical systems.

This special issue focuses on theoretical and technological achievements in cooperative multiagent Systems. It contains twenty-six papers, the contents of which are summarized below.

A Performance Study Of Genetic Algorithm-Assisted Beamforming In Distributed Cognitive Radio Networks, Andrew Minturn

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

Cognitive Radio (CR) is a technology that has gained much interest recently due to the increasing scarcity of the radio frequency spectrum. Large portions of the radio frequency spectrum are licensed to users who then have exclusive access to the bandwidth, and unlicensed bands can be a challenge to use due to interference from unlicensed users. Despite the seeming scarcity, tests of bands allocated by the Federal Communications Committee (FCC) to licensed and unlicensed user have shown that many are underutilized and often unoccupied by the user to whom they are licensed. CR aims to exploit this unused spectrum and …

A Comparative Study Of Generalized Arc-Consistency Algorithms, Olufikayo S. Adetunji

School of Computing: Dissertations, Theses, and Student Research

In this thesis, we study several algorithms for enforcing Generalized Arc­-Consistency (GAC), which is the most popular consistency property for solving Constraint Satisfaction Problems (CSPs) with backtrack search. The popularity of such algorithms stems from their relative low cost and effectiveness in improving the performance of search. Virtually all commercial and public- domain constraint solvers include some implementation of a generic GAC algorithm. In recent years, several algorithms for enforcing GAC have been proposed in the literature that relies on increasingly complex data structures and mechanisms to improve performance. In this thesis, we study, assess, and compare a basic algorithm …

Stable And Metastable Nanowires Displaying Locally Controllable Properties, Eli A. Sutter, Peter Werner Sutter

Department of Electrical and Computer Engineering: Faculty Publications

(57) ABSTRACT Vapor-liquid-solid growth of nanowires is tailored to achieve complex one-dimensional material geometries using phase diagrams determined for nanoscale materials. Segmented one-dimensional nanowires having constant composition dis play locally variable electronic band structures that are deter mined by the diameter of the nanowires. The unique electrical and optical properties of the segmented nanowires are exploited to form electronic and optoelectronic devices. Using gold-germanium as a model system, in situ transmis sion electron microscopy establishes, for nanometer-sized Au Ge alloy drops at the tips of Ge nanowires (NWs), the parts of the phase diagram that determine their temperature dependent equilibrium …

Cubic Spline Interpolation By Solving A Recurrence Equation Instead Of A Tridiagonal Matrix, Peter Revesz

School of Computing: Conference and Workshop Papers

The cubic spline interpolation method is proba- bly the most widely-used polynomial interpolation method for functions of one variable. However, the cubic spline method requires solving a tridiagonal matrix-vector equation with an O(n) computational time complexity where n is the number of data measurements. Even an O(n) time complexity may be too much in some time-ciritical applications, such as continuously estimating and updating the flight paths of moving objects. This paper shows that under certain boundary conditions the tridiagonal matrix solving step of the cubic spline method could be entirely eliminated and instead the coefficients of the unknown cubic polynomials …

Designing A Bayer Filter With Smooth Hue Transition Interpolation Using The Xilinx System Generator, Zhiqiang Li, Peter Revesz

School of Computing: Conference and Workshop Papers

This paper describes the design of a Bayer filter with smooth hue transition using the System Generator for DSP. We describe and compare experimentally two different designs, one based on a MATLAB implementation and the other based on a modification of the Bayer filter using bilinear interpolation.

A Game-Theoretic Analysis Of The Nuclear Non-Proliferation Treaty, Peter Revesz

School of Computing: Conference and Workshop Papers

Although nuclear non-proliferation is an almost universal human desire, in practice, the negotiated treaties appear unable to prevent the steady growth of the number of states that have nuclear weapons. We propose a computational model for understanding the complex issues behind nuclear arms negotiations, the motivations of various states to enter a nuclear weapons program and the ways to diffuse crisis situations.

Estimating The Flight Path Of Moving Objects Based On Acceleration Data, Peter Revesz

School of Computing: Conference and Workshop Papers

Inertial navigation is the problem of estimating the flight path of a moving object based on only acceleration measurements. This paper describes and compares two approaches for inertial navigation. Both approaches estimate the flight path of the moving object using cubic spline interpolation, but they find the coefficients of the cubic spline pieces by different methods. The first approach uses a tridiagonal matrix, while the second approach uses recurrence equations. They also require different boundary conditions. While both approaches work in O(n) time where n is the number of given acceleration measurements, the recurrence equation-based method can be easier updated …

A Comparative Study Of Underwater Robot Path Planning Algorithms For Adaptive Sampling In A Network Of Sensors, Sreeja Banerjee

School of Computing: Dissertations, Theses, and Student Research

Monitoring lakes, rivers, and oceans is critical to improving our understanding of complex large-scale ecosystems. We introduce a method of underwater monitoring using semi-mobile underwater sensor networks and mobile underwater robots in this thesis. The underwater robots can move freely in all dimension while the sensor nodes are anchored to the bottom of the water column and can move only up and down along the depth of the water column. We develop three different algorithms to optimize the path of the underwater robot and the positions of the sensors to improve the overall quality of sensing of an area of …

Expected Cost Penalty Due To Deviation From Security-Constrained Dispatch, Veravut Dheraprasart

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

This thesis introduces and evaluates a new index called ”Expected Cost Penalty Due to Deviation From Security Constrained Dispatch” (ECP_SCD) for interconnected power systems planning. This index represents the optimal operating cost of the system taking into account the uncertainties such as random failure of generating units, transformer, and transmission lines in interconnected power systems. The significance of this index is that it represents the minimum operating cost for a contingency event and can be used for contingency screening (ranking). This index also indicates the impact of equipment reliability on the average cost penalty of all contingency events. Moreover, this …

A Methodology And Tool For Concurrent Fault Injection, Zhongyin Zhang

School of Computing: Dissertations, Theses, and Student Research

As the speed of microprocessors tails off, utilizing multiple processing cores per chip is becoming a common way for developers to achieve higher performance. However, writing concurrent programs can be a big challenge because of common concurrency faults. Because concurrency faults are hard to detect and reproduce, traditional testing techniques are not suitable. New techniques are needed, and these must be assessed. A typical method for assessing testing techniques is to embed faults in programs using mutation tools, and assess the ability of techniques to detect these. Although mutation testing techniques can be used to represent common faults, approaches for …

Performance Analysis Of Mobile Ad-Hoc Routing Protocols By Varying Mobility, Speed And Network Load, Nilotpal Sarmah

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

One of the most promising network that has emerged from the technology world is the mobile ad-hoc network or MANET. It is a type of multi-hop network. Wireless by nature, MANETs do not have a specific network infrastructure. It is a collection of wireless mobile devices that communicate with each other without the help of any third party backbone like a base-station or a router. It can be hard to imagine how every node in this type of network communicate with one another without having a router. In MANETs, nodes change locations with time, configure themselves and get the information …

Growth Of Graphene Films And Graphene Patterns, Yongfeng Lu, Wei Xiong, Yunshen Zhou

Department of Electrical and Computer Engineering: Faculty Publications

Large area graphene can be fabricated by depositing carbon and catalytic metal thin film(s) on a substrate, heating the carbon and the catalytic metal, and forming graphene on the substrate. The catalytic metal is evaporated during the heating process. The catalytic metal can be, for example, nickel, cobalt, or iron.

Measuring Autonomy And Solving General Stabilization Problems With Multi-Agent Systems, Rasheed A. Rajabzadeh

School of Computing: Dissertations, Theses, and Student Research

Many distributed complex problems address a particular form of resource scheduling where proper resource management can cut costs by stabilizing a set of stochastic fluctuating parameters. Wireless sensor network communication, supply chain management, stock trading, intelligent traffic management, and smart grid systems are examples of these problems. Among the various solutions, a common strategy often used to address this type of problems is fluctuation reduction via resource buffering combined with load shifting. Respectively, stable wireless communication, demand for supplies, liquidity, traffic speed, and power demand reduce cost and can be achieved by properly managing sensor data buffers, warehouses, capital, distance …

Thickness Determination Of Few-Layer Hexagonal Boron Nitride Films By Scanning Electron Microscopy And Auger Electron Spectroscopy, P. Sutter, E. Sutter

Department of Electrical and Computer Engineering: Faculty Publications

We assess scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) for thickness measurements on few-layer hexagonal boron nitride (h-BN), the layered dielectric of choice for integration with graphene and other two-dimensional materials. Observations on h-BN islands with large, atomically flat terraces show that the secondary electron intensity in SEM reflects monolayer height changes in films up to least 10 atomic layers thickness. From a quantitative analysis of AES data, the energy-dependent electron escape depth in h-BN films is deduced. The results show that AES is suitable for absolute thickness measurements of few-layer h-BN of 1 to 6 layers.

Self-Organizing Microstructures Orientation Control In Femtosecond Laser Patterning On Silicon Surface, Pengjun Liu, Lan Jiang, Jie Hu, Shuai Zhang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Self-organizing rippled microstructures are induced on silicon surface by linearly polarized femtosecond laser pulses. At a near threshold fluence, it is observed that ripple orientation is co-determined by the laser polarization direction and laser scanning parameters (scanning direction and scanning speed) in surface patterning process. Under fixed laser polarization, the ripple orientation can be controlled to rotate by about 40° through changing laser scanning parameters. In addition, it is also observed that the ripple morphology is sensitive to the laser scanning direction, and it is an optimal choice to obtain ordered ripple structures when the angle between laser scanning and …

Human Brain Networks: Spiking Neuron Models, Multistability, Synchronization, Thermodynamics, Maximum Entropy Production, And Anesthetic Cascade Mechanisms, Wassim H. Haddad, Qing Hui, James M. Bailey

Department of Electrical and Computer Engineering: Faculty Publications

Advances in neuroscience have been closely linked to mathematical modeling beginning with the integrate-and-fire model of Lapicque and proceeding through the modeling of the action potential by Hodgkin and Huxley to the current era. The fundamental building block of the central nervous system, the neuron, may be thought of as a dynamic element that is “excitable”, and can generate a pulse or spike whenever the electrochemical potential across the cell membrane of the neuron exceeds a threshold. A key application of nonlinear dynamical systems theory to the neurosciences is to study phenomena of the central nervous system that exhibit nearly …

Ultimate Codes: Near-Optimal Mds Array Codes For Raid-6, Zhijie Huang, Hong Jiang, Chong Wang, Ke Zhou, Yuhong Zhao

School of Computing: Technical Reports

As modern storage systems have grown in size and complexity, RAID-6 is poised to replace RAID-5 as the dominant form of RAID architectures due to its ability to protect against double disk failures. Many excellent erasure codes specially designed for RAID-6 have emerged in recent years. However, all of them have limitations. In this paper, we present a class of near perfect erasure codes for RAID-6, called the Ultimate codes. These codes encode, update and decode either optimally or nearly optimally, regardless of what the code length is. This implies that utilizing these codes we can build highly efficient and …