Engineering Commons^™

An Estimation Of Distribution Improved Particle Swarm Optimization Algorithm, Raghavendra V. Kulkarni, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

PSO is a powerful evolutionary algorithm used for finding global solution to a multidimensional problem. Particles in PSO tend to re-explore already visited bad solution regions of search space because they do not learn as a whole. This is avoided by restricting particles into promising regions through probabilistic modeling of the archive of best solutions. This paper presents hybrids of estimation of distribution algorithm and two PSO variants. These algorithms are tested on benchmark functions having high dimensionalities. Results indicate that the methods strengthen the global optimization abilities of PSO and therefore, serve as attractive choices to determine solutions to …

Detecting Malicious Logic Through Structural Checking, Scott C. Smith, Jia Di

Electrical and Computer Engineering Faculty Research & Creative Works

Hardware is just as susceptible as software to "hacker attacks", through inclusion of malicious logic; and the consequences of such an attack could be disastrous! the impact of software viruses has been felt, at one time or another, by the entire computerized world, through loss of productivity, loss of system resources or data, or mere inconvenience. However, the nature of malicious logic and defending against it is fundamentally different from its software counterpart. Malicious logic has the added dimension of not being removable once encapsulated in the system. This paper will identify hardware vulnerabilities and will outline an automated method, …

Nanofabric Pla Architecture With Redundancy Enhancement, Mandar V. Joshi, Waleed K. Al-Assadi

Electrical and Computer Engineering Faculty Research & Creative Works

Fundamental electronic structures such as Diodes and FETs have been shown to be constructed using selectively doped semiconducting Carbon Nanotubes or Silicon Nanowires (CNTs, SiNWs) at nanometer scale. Memory and Logic cores have been proposed, that use the configurable junctions in 2-D crossbars of CNTs. These Memory and Logic arrays at this scale exhibit a significant amount of defects that account for poor a yield. Configuration of these devices in the presence of defects demands an overhead in terms of area and programming time. This work introduces a PLA configuration that makes use of fixed and adaptive redundancy in terms …

Neural-Network-Based Intelligent Control For Improving Dynamic Performance Of Facts Devices, Wei Qiao, Ronald G. Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Flexible ac transmission system (FACTS) devices are widely recognized as powerful controllers to improve the dynamic performance and stability of power systems. the standard FACTS controllers are linear controllers designed around a specific operating point from a linearized system model with fixed parameters. However, at other operating points their performance degrades. Neural-network-Based nonlinear intelligent control offers an attractive approach to overcome the drawbacks of the linear controllers. This paper presents two different neural-network-Based intelligent control architectures, i.e., indirect adaptive NeuroControl and adaptive critic design based optimal NeuroControl, for designing the external control of an SSSC FACTS device. Simulation studies are …

Novel And Efficient Download Test For Two Path Echo Canceller, Mohammad Asif Iqbal, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

The two-path echo cancellation technique is a popular method for handling the double-talk problem in acoustic and line echo cancellation applications. the method uses two filters. a so-called background adaptive filter adapts its coefficients to predict echo all or most of the time regardless of signal activity on the near end. a second foreground filter, that also predicts the echo, receives it coefficients from the background filter, but only when the background is performing better than the foreground. Only the foreground residual echo is sent to the far-end. so any background divergence due to double-talk is not observed by the …

Self-Healing Control With Multifunctional Gate Drive Circuits For Power Converters, Xiao Peng, Ganesh K. Venayagamoorthy, Keith A. Corzine, Robert Woodley

Electrical and Computer Engineering Faculty Research & Creative Works

Many commercial and military transport systems have fault diagnostic functions implemented to help protect the device when a severe fault occurs. However, most present systems do not contain prognostics capability which would allow operators to observe an unhealthy system component in its prefault condition. in industry applications, scheduled downtime can result in considerable cost avoidance. the next technology step is self-healing system components which observe not only potential problems but can also take steps to continue operation under abnormal conditions - whether due to long-term normal wear-and-tear or sudden combat damage. in this paper, current and voltage information using the …

Electromagnetic Simulation For Inhomogeneous Interconnect And Packaging Structures, Lijun Jiang, Barry J. Rubin, Yuan Liu, Jason D. Morsey, Alina Deustch

Electrical and Computer Engineering Faculty Research & Creative Works

The paper contains a novel mechanism for full wave electromagnetic simulation of complicated inhomogeneous structures, such as on-chip interconnects, IC packaging, antennas, and scattering objects. It uses only Equivalent Principle based EFIE instead of both EFIE and MFIE to establish the surface integral equations for practical inhomogeneous structure so that a much more simplified formulation process is needed in the EM simulation procedure. To overcome the numerical error of K operator in the formulation, a new analytical solution to the K operator for general full-wave integral equations is provided. Numerical results are demonstrated to verify the proposed algorithm. © 2007 …

Moment Analysis Of Near-Equilibrium Binding Interactions During Electrophoresis, Yousef Daneshbod, James D. Sterling, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

The electrophoretic transport of three chemically reacting species, two of which can bind reversibly to form the third, is analyzed mathematically. The species are assumed to move horizontally through a long channel with different electrophoretic mobilities and diffusion coefficients. By considering small perturbations of the system about equilibrium or when one of the two binding species is much more abundant than the other, the governing advection-reaction- diffusion equations can be linearized and studied via the method of moments. The result is a set of coupled ordinary differential equations for the moments that can be solved analytically. Analysis of the long-time …

Trenchless Water Pipe Condition Assessment Using Artificial Neural Network, Zong Woo Geem, Chung-Li Tseng, Juhwan Kim, Cheolho Bae

Engineering Management and Systems Engineering Faculty Research & Creative Works

In order to assess the water pipe condition without excavating, artificial neural network (ANN) model was developed and applied to real-world case in South Korea. for the input in this ANN model, 11 factors such as (1) pipe material, (2) diameter, (3) pressure head, (4) inner coating, (5) outer coating, (6) electric recharge, (7) bedding condition, (8) age, (9) trench depth, (10) soil condition, and (11) number of road lanes were used; and, for the output, overall pipe condition index was derived based on 5 factors such as (1) outer corrosion, (2) crack, (3) pin hole, (4) inner corrosion, and …

Assurance Cases For Security: The Metrics Challenge, Robin Bloomfield, Marcelo Masera, Ann K. Miller, O. Sami Saydjari, Charles B. Weinstock

Electrical and Computer Engineering Faculty Research & Creative Works

For critical systems it is important to know whether the system is trustworthy and to be able to communicate, review and debate the level of trust achieved. in the safety domain, explicit Safety Cases are increasingly required by law, regulations and standards. Yet the need to understand risks is not just a safety issue and the type of argumentation used for safety cases is not specific to safety alone. Prior workshops, beginning with one held at DSN 2004, have identified a number of technical, policy and research challenges. the focus of this workshop is on one of these challenges: metrics …

Effects Of Electromagnetic Interference On Control Area Network Performance, Fei Ren, Y. Rosa Zheng, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the effects of electromagnetic interference (EMI) on control area network (CAN) communications are investigated by hardware experiments. Distinct CAN bit rates, communication cables, and networks are used to test effects of EMI on CAN bus. Waveforms of CAN data frames in EMI environment are observed and analyzed for figuring out details of effects. Experiments show that the EMI pulses frequently encountered in automobile and off-road machinery can cause the reduction of bit rates and errors in high-speed CAN communications. Replacing traditional unshielded parallel communication cables with shielded communication cables is proved to be an effective method of …

Predictive Congestion Control Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Available congestion control schemes, for example transport control protocol (TCP), when applied to wireless networks, result in a large number of packet drops, unfair scenarios and low throughputs with a significant amount of wasted energy due to retransmissions. To fully utilize the hop by hop feedback information, this paper presents a novel, decentralized, predictive congestion control (DPCC) for wireless sensor networks (WSN). The DPCC consists of an adaptive flow and adaptive back-off interval selection schemes that work in concert with energy efficient, distributed power control (DPC). The DPCC detects the onset of congestion using queue utilization and the embedded channel …

Comparative Application Of Differential Evolution And Particle Swarm Techniques To Reactive Power And Voltage Control, G. A. Bakare, G. Krost, Ganesh K. Venayagamoorthy, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the comparative application of two metaheuristic approaches: Differential Evolution (DE) and Particle Swarm Optimization (PSO) to the solution of the reactive power and voltage control problem. Efficient distribution of reactive power in an electric network leads to minimization of the system losses and improvement of the system voltage profile. It can be achieved by varying the excitation of generators or the on-load tap changer positions of transformers as well as by switching of discrete portions of inductors or capacitors etc. This constitutes a typical mixed integer non-linear optimization problem for the solution of which metaheuristic techniques have …

A Gray-Code Type Bit Assignment Algorithm For Unitary Space-Time Constellations, Adam Panagos, Kurt Louis Kosbar

Electrical and Computer Engineering Faculty Research & Creative Works

Many techniques for constructing unitary space- time constellations have been proposed. To minimize bit-error rate (BER) in a wireless communication system, constellations constructed using these techniques should be given a Gray- code type bit assignment, where symbols which are close in signal space have bit assignments which have small Hamming distance. To the authors' knowledge, no efficient general strategy for making this bit assignment has been suggested. This work proposes a prioritized distance (PD) algorithm for making this assignment in an optimal manner by minimizing the probability of bit error union bound. The algorithm can be used on constellations constructed …

The Existence Of Multiple Equilibria In The Upfc Power Injection Model, Mahyar Zarghami, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This letter shows the existence of multiple equilibria that arise from the use of the state model of the unified power flow controller (UPFC). These multiple equilibria can arise from a common power injection model for the same terminal conditions of shunt bus voltage and series active and reactive power injections. The multiple equilibria result in two or more sets of eigenvalues, some of which may indicate an unstable operating condition. Therefore, the use of the UPFC power injection model must be used with caution to ensure stable operation of the UPFC.

Modeling Noise Coupling Between Package And Pcb Power/Ground Planes With An Efficient 2-D Fdtd/Lumped Element Method, Ting-Kuang Wang, Sin-Ting Chen, Chi-Wei Tsai, Sung-Mao Wu, James L. Drewniak, Tzong-Lin Wu

Electrical and Computer Engineering Faculty Research & Creative Works

An efficient numerical approach based on the 2-D finite-difference time-domain (FDTD) method is proposed to model the power/ground plane noise or simultaneously switching noise (SSN), including the interconnect effect between the package and the print circuit board (PCB). The space between the power and ground planes on the package and PCB are meshed with 2-D cells. The equivalent R-L-C circuits of the via and the solder balls connecting the package and PCB can be incorporated into a 2-D Yee cell based on a novel integral formulation in the time domain. An efficient recursive updating algorithm is proposed to fit the …

Estimation Of High-Frequency Currents From Near-Field Scan Measurements, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff, Jin Shi

Electrical and Computer Engineering Faculty Research & Creative Works

High-frequency currents on the pins of integrated circuits (ICs) and on printed circuit board (PCB) traces are needed to predict and analyze electromagnetic interference in high-speed devices. These currents can, however, be difficult to measure when traces are buried within the PCB or chip-package, especially when several current-carrying traces are in close proximity. Techniques for estimating high-frequency currents from near-field scan data are proposed in this paper. These techniques are applied to find currents on the pins of an IC, on traces buried beneath other traces in a PCB, and on traces over a slot in the ground plane. Methods …

Hybrid Of Scattering Matrix Method And Integral Equation Used For Co-Simulation Of Power Integrity And Emi In Electronic Package With Large Number Of P/G Vias, Zaw Zaw Oo, En Xiao Liu, Xing Chang Wei, Mark Tan Yew Choon, Er Ping Li, Yaojiang Zhang, Le Wei Li

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents the development of a coupled scattering matrix method (SMM) with integral equation method for analyzing the power integrity (PI) of multilayered package structure with large number of power/grounds vias. Analysis of the entire signal traces and the associated vias, connected between the power and ground, (named as P/G vias) is treated as analyzing the coupling between the external signal traces and the inside vertical vias, and analyzing the scattering effects between the vertical vias. a pair of the layered power/ground planes is considered as the parallel plate waveguide structure. the scattering matrix method for the parallel-plate waveguide …

Optimal Control Of Class Of Non-Linear Plants Using Artificial Immune Systems: Application Of The Clonal Selection Algorithm, S. A. Panimadai Ramaswamy, Ganesh K. Venayagamoorthy, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

The function of natural immune system is to protect the living organisms against invaders/pathogens. Artificial Immune System (AIS) is a computational intelligence paradigm inspired by the natural immune system. Diverse engineering problems have been solved in the recent past using AIS. Clonal selection is one of the few algorithms that belong to the family of AIS techniques. Clonal selection algorithm is the computational implementation of the clonal selection principle. The process of affinity maturation of the immune system is explicitly incorporated in this algorithm. This paper presents the application of AIS for the optimal control of a class of non-linear …

Design Of A Logic Element For Implementing An Asynchronous Fpga, Scott C. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

A reconfigurable logic element (LE) is developed for use in constructing a NULL Convention Logic (NCL) FPGA. It can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, and can utilize embedded registration for gates with three or fewer inputs. the developed LE is compared with a previous NCL LE, showing that the one developed herein yields a more area efficient NCL circuit implementation. the NCL FPGA logic element is simulated at the transistor level using the 1.8V, 180nm TSMC CMOS process. Copyright 2007 ACM.

Steel Sheet Sheathing Options For Cfs Framed Shear Wall Assemblies Providing Shear Resistance, Cheng Yu, Hitesh Vora, Tony Dainard, Jimmy Tucker, Pradeep Veetvkuri

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The North American Standard for Cold-Formed Steel Framing - Lateral Design, AISI S213-07, provides design provisions for cold-formed steel framed shear walls with steel sheet sheathing. However, options are limited to 18-mil and 27-mil steel sheet sheathing. Presented in this report are the findings from an extensive monotonic and cyclic testing program conducted at the University of North Texas of 30-mil and 33-mil steel sheet sheathed shear walls with 2:1 and 4:1 aspect ratios and 27-mil sheet steel shear walls with 2:1 aspect ratio and 6-in., 4-in., 3-in., and 2-in. fastener spacing at panel edges. It is anticipated that the …

North American Standard For Cold-Formed Steel Framing -- Floor And Roof System Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Cold-Formed Steel Framing Design Guide, Second Edition, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

This Design Guide has been developed under the direction of the American Iron and Steel Institute Committee on Specifications for the Design of Cold-Formed Steel Structural Members. The development of the Guide was sponsored by the American Iron and Steel Institute and the Steel Stud Manufacturers Association. The AISI Committee on Specifications wishes to acknowledge and express gratitude to Mr. Thomas Trestain of T. W. J. Trestain Structural Engineering who was the author of this Guide.

With anticipated improvements in understanding of the behavior of cold-formed steel and the continuing development of new technology, this material might become dated. It …

North American Standard For Cold-Formed Steel Framing -- Wall Stud Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Enhanced Shrinkage Of Lanthanum Strontium Manganite (La0.90sr0.10mno3+Δ) Resulting From Thermal And Oxygen Partial Pressure Cycling, Benjamin P. Mccarthy, Larry R. Pederson, Harlan U. Anderson, Xiao Dong Zhou, Prabhakar Singh, Gregory W. Coffey, Edwin C. Thomsen

Materials Science and Engineering Faculty Research & Creative Works

Exposure of (La_0.90Sr_0.10)_0.98MnO_3+δ (LSM-10) to repeated oxygen partial pressure cycles (air/10 ppm O₂) resulted in enhanced densification rates, similar to behavior shown previously due to thermal cycling. Shrinkage rates in the temperature range 700°-1000°C were orders of magnitude higher than Makipirtti-Meng model estimations based on stepwise isothermal dilatometry results at a high temperature. a maximum in enhanced shrinkage due to oxygen partial pressure cycling occurred at 900°C. Shrinkage was the greatest when LSM-10 bars that were first equilibrated in air were exposed to gas flows of lower oxygen fugacity than in …

Dft Techniques And Automation For Asynchronous Null Conventional Logic Circuits, Venkat Satagopan, Waleed K. Al-Assadi, Scott C. Smith, Sindhu Kakarla, Bonita Bhaskaran

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional automatic test pattern generation (ATPG) algorithms fail when applied to asynchronous NULL convention logic (NCL) circuits due to the absence of a global clock and presence of more state-holding elements, leading to poor fault coverage. This paper presents a design-for-test (DFT) approach aimed at making asynchronous NCL designs testable using conventional ATPG programs. We propose an automatic DFT insertion flow (ADIF) methodology that performs scan and test point insertion on NCL designs to improve test coverage, using a custom ATPG library. Experimental results show significant increase in fault coverage for NCL cyclic and acyclic pipelined designs.

Neural Network Based Decentralized Controls Of Large Scale Power Systems, Wenxin Liu, Jagannathan Sarangapani, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Mariesa Crow, Li Liu, David A. Cartes

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a suite of neural network (NN) based decentralized controller designs for large scale power systems' generators, one is for the excitation control and the other is for the steam valve control. Though the control inputs are calculated using local signals, the transient and overall system stability can be guaranteed. NNs are used to approximate the unknown and/or imprecise dynamics of the local power system dynamics and the inter-connection terms, thus the requirements for exact system parameters are relaxed. Simulation studies with a three-machine power system demonstrate the effectiveness of the proposed controller designs.

Use Of Max-Flow On Facts Devices, Adam Lininger, Bruce M. Mcmillin, Badrul H. Chowdhury, Mariesa Crow

Computer Science Faculty Research & Creative Works

FACTS devices can be used to mitigate cascading failures in a power grid by controlling the power flow in individual lines. Placement and control are significant issues. We present a procedure for determining whether a scenario can be mitigated using the concept of maximum flow. If it can be mitigated, we determine what placement and control setting will solve the scenario. This paper treats fourteen cascading failure scenarios and reports on the use of the max-flow algorithm both in determining the mitigation of each scenario and in finding FACTS settings that will mitigate the scenario.

Inference Of Genetic Regulatory Networks With Recurrent Neural Network Models Using Particle Swarm Optimization, Rui Xu, Donald C. Wunsch, Ronald L. Frank

Electrical and Computer Engineering Faculty Research & Creative Works

Genetic regulatory network inference is critically important for revealing fundamental cellular processes, investigating gene functions, and understanding their relations. The availability of time series gene expression data makes it possible to investigate the gene activities of whole genomes, rather than those of only a pair of genes or among several genes. However, current computational methods do not sufficiently consider the temporal behavior of this type of data and lack the capability to capture the complex nonlinear system dynamics. We propose a recurrent neural network (RNN) and particle swarm optimization (PSO) approach to infer genetic regulatory networks from time series gene …

Phase Transformations Of Calcium Phosphates Formed In Wet Field Environments, O. M. Clarkin, Mark R. Towler, G. M. Insley, M. E. Murphy

Chemical and Biochemical Engineering Faculty Research & Creative Works

The crystal phase and morphology of calcium phosphate salts precipitated in a wet field environment at temperatures between 30 and 70 °C and pHs between 3 and 8 were examined. Dicalcium Phosphate Dihydrate (DCPD) was the most prevalent phase precipitated. Using accelerated ageing study techniques, precipitates studied were aged, under dry conditions at 50 °C for 8 and 16 days, before being re-examined using XRD, FTIR and SEM techniques. DCPD was found to be most stable when precipitated at 40 °C and 5 pH. Considerably more phase transformation to Octacalcium Phosphate (OCP), Amorphous Calcium Phosphate (ACP) and Hydroxyapatite (HA) was …