Digital Commons Network^™

The Subcircuit Extraction Problem, Nian Zhang, Donald C. Wunsch, Frank Harary

Electrical and Computer Engineering Faculty Research & Creative Works

The steady down scaling of CMOS device dimensions has been the main stimulus to the growth of microelectronics and computer aided very large scale integration (VLSI) design. But the more an integrated circuit (IC) is scaled, the higher its packing density becomes. The increasing size of chips, measured in either area or number of transistors, and the waste of the large capital investment involved in fabricating and testing circuits that do not work, make layout analysis and verification an important part of physical design automation. The most efficient way to overcome these difficulties is to identify a related collection of …

A Discrete-Time Model For Spatio-Temporally Correlated Mimo Wssus Multipath Channels, Chengshan Xiao, Jingxian Wu, Sang-Yick Leong, Y. Rosa Zheng, Khaled Ben Letaief

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a statistical discrete-time model is proposed for simulating wideband MIMO channels which experience spatially and temporally correlated, widesense stationary uncorrelated scattering (WSSUS) multipath Rayleigh fading. A new method is also presented to efficiently generate the correlated MIMO channel coefficients, which can be used for accurate simulation of physical continuous-time MIMO channel. The statistic accuracy of the discrete-time MIMO channel model is rigorously verified through theoretical analysis and extensive simulations in different criteria.

A Statistical Simulation Model For Mobile Radio Fading Channels, Chengshan Xiao, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, a Clarke's model-based simulator was proposed for Rayleigh fading channels. However, that model, as shown in this paper, may encounter statistic deficiency. Therefore, an improved model is presented to remove the statistic deficiency. Furthermore, a new simulation model is proposed for Rician fading channels. This Rician fading simulator with finite number of sinusoids plus a zero-mean stochastic sinusoid as the specular (line-of-sight) component is different from all the existing Rician fading simulators, which have non-zero mean deterministic specular component. The statistical properties of the proposed Rayleigh and Rician fading channel models are analyzed in detail, which shows that these …

Adaptive Critic Design Based Neurocontroller For A Statcom Connected To A Power System, Salman Mohagheghi, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

A novel nonlinear optimal neurocontroller for a static compensator (STATCOM) connected to a power system using artificial neural networks is presented in this paper. The heuristic dynamic programming (HDP), a member of the adaptive critic designs (ACDs) family, is used for the design of the STATCOM neurocontroller. This neurocontroller provides nonlinear optimal control with better performance compared to the conventional PI controllers.

Adaptive Critic Designs And Their Implementations On Different Neural Network Architectures, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design of nonlinear optimal neurocontrollers based on the Adaptive Critic Designs (ACDs) family of algorithms has recently attracted interest. This paper presents a summary of these algorithms, and compares their performance when implemented on two different types of artificial neural networks, namely the multilayer perceptron neural network (MLPNN) and the radial basis function neural network (RBFNN). As an example for the application of the ACDs, the control of synchronous generator on an electric power grid is considered and results are presented to compare the different ACD family members and their implementations on different neural network architectures.

Natural Radioactivity Of Uae Coastal Areas, Yaqoub Abdalla Mohamed Al-Ali

Theses

Many materials that are usually found in the earth's crust contain small but measurable amount of naturally occurring radioactivity.

In the present study, the natural radioactivity due to the presence of ²³⁸U, ²³²Th and ⁴⁰K in beach sand along the UAE costal line has been measured. The measurements were performed using gamma-ray spectrometry with a high-purity Germanium (HPGe) detector connected to a multi-channel analyzer.

Chapter 1 includes an introduction about natural radioactivity, gamma ray spectrometry, types of detectors employed and analysis of gamma ray spectra. A literature review of the related work is also included at the …

Instance Based Attribute Identification In Database Integration, Ee Peng Lim, Cecil Chua, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

Most research on attribute identification in database integration has focused on integrating attributes using schema and summary information derived from the attribute values. No research has attempted to fully explore the use of attribute values to perform attribute identification. We propose an attribute identification method that employs schema and summary instance information as well as properties of attributes derived from their instances. Unlike other attribute identification methods that match only single attributes, our method matches attribute groups for integration. Because our attribute identification method fully explores data instances, it can identify corresponding attributes to be integrated even when schema information …

A Simulation Model To Characterize Photolithography Process Of A Semiconductor Wafer Fabrication, Amr Arisha, Paul Young, Mohie El Baradie

Articles

The pressures on semiconductor manufacturers due to cost considerations, rapid growth of process technology, quality constraints, feature size reduction, and increasingly complex products are requiring ever higher efficiency from manufacturing facilities. The complexity of manufacturing high capacity semiconductor devices means that it is impossible to analyze the process control parameters and the production configurations using traditional analytical models. There is, therefore, an increasing need for effective models of each manufacturing process, characterizing and analyzing the process in detail, allowing the effect of changes in the production environment on the process to be predicted. The photolithography process is one of the …

Sensor Networks: An Overview, Malik Tubaishat, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Advances in hardware and wireless network technologies have created low-cost, low-power, multifunctional miniature sensor devices. These devices make up hundreds or thousands of ad hoc tiny sensor nodes spread across a geographical area. These sensor nodes collaborate among themselves to establish a sensing network. A sensor network can provide access to information anytime, anywhere by collecting, processing, analyzing and disseminating data. Thus, the network actively participates in creating a smart environment.

Involving Engineering With In-Service K-4 Teachers, Theresa M. Swift, Steve Eugene Watkins, Kristine Swenson, Evalee Lasater, Robert Mitchell

Electrical and Computer Engineering Faculty Research & Creative Works

A strong workforce in science and engineering and literate citizens in a technology-based society depends on an educational system that prepares students in science, mathematics, and engineering. Unfortunately, many K-12 students lose interest in such topics early in their school years. Engineering applications can capture the imagination of students and illustrate the concepts in science and mathematics. Level-appropriate resources are as necessary for primary teachers and our young scholars as for teachers and students in higher grades. A model for interaction between engineers and K-4 teachers is proposed. The State of Missouri defines curriculum standards in each subject area and …

Two Distributed Algorithms For E-Ticket Validation Protocols For Mobile Clients, H. Mohanty, Sanjay Kumar Madria, T. Suman Kumar Reddy, R. K. Ghosh

Computer Science Faculty Research & Creative Works

The e-ticket (electronic ticket) validation problem has relevance in mobile computing environment because of the multiple submission of a ticket that is possible due to intermittent disconnections and mobility of hosts. Here, we propose protocols that are not only sensitive to disconnection but also to location. One of the proposed protocols is the variant of the distributed protocol proposed by Pedone (2000) for Internet users. This shows that a distributed protocol for static network can be restructured for distributed computation in a mobile computing environment. We have also proposed another protocol that uses a hierarchical location database of mobile hosts …

Dynamic Nonlinear Effect On Lasing In Random Media, B. Liu, Alexey Yamilov, Y. Ling, J. Y. Xu, Hui Cao

Physics Faculty Research & Creative Works

We investigate the dynamic effect of nonlinearity on lasing in disordered medium. The third-order nonlinearity not only changes frequency and size of lasing mode, but also modifies laser emission intensity and laser pulse width.

A Hmm Based Semantic Analysis Framework For Sports Game Event Detection, Gu Xu, Yu-Fei Ma, Hong-Jiang Zhang, Shiqiang Yang

Chemistry Faculty Research & Creative Works

Video events detection or recognition is one of important tasks in semantic understanding of video content. Sports game video should be considered as a rule-based sequential signal. Therefore, it is reasonable to model sports events using hidden Markov models. In this paper, we present a generic, scalable and multilayer framework based on HMMs, called SG-HMMs (sports game HMMs), for sports game event detection. At the bottom layer of this framework, event HMMs output basic hypotheses based on low-level features. The upper layers are composed of composition HMMs, which add constraints on those hypotheses of the lower layer. Instead of isolated …

Deuterium Nmr Studies Of Bulk And Silica-Absorbed Polystyrene, Macduff O. Okuom, Jinhua Yang, Frank D. Blum

Chemistry Faculty Research & Creative Works

Thin polymer films are used in applications such as electronics, biomedical devices and coatings. As the trend to make the devices smaller continues, a film's influence on a material's overall properties becomes more prominent. Previous studies have shown that thin polymer films have characteristics slightly different from those of bulk polymers. Film behavior has been characterized by examining thermal expansion, diffusion, conformation, density and glass transitions. The dynamics of glassy polystyrene has been investigated using a wide variety of theoretical and experimental methods. Schaefer et al., using 13C NMR, reported that ~7% of phenyl rings in polystyrene undergo -flips. Using …

Molecular Mass And Dynamics In Pma-D₃ In The Glass Transition Region, Burak Metin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The segmental dynamics through the glass transition region, by which the glassy polymer becomes rubbery, are not well understood. Free volume, thermodynamic and kinetic theories have been used to describe the phenomenon behind the glass transition and some of those theories were tested with computer simulations. Different experimental techniques, such as NMR, thermo-mechanical analysis (TMA), differential scanning calorimetry (DSC), dilatometry and dynamic mechanical analysis (DMA) have all been also used to probe this important phenomena. Deuterium (2H) NMR has been a valuable tool for the investigation of the dynamics of macromolecules. Deuteration of macromolecules at specific locations on the chains …

Intelligent Strain Sensing On A Smart Composite Wing Using Extrinsic Fabry-Perot Interferometric Sensors And Neural Networks, Kakkattukuzhy M. Isaac, Donald C. Wunsch, Steve Eugene Watkins, Rohit Dua, V. M. Eller

Electrical and Computer Engineering Faculty Research & Creative Works

Strain prediction at various locations on a smart composite wing can provide useful information on its aerodynamic condition. The smart wing consisted of a glass/epoxy composite beam with three extrinsic Fabry-Perot interferometric (EFPI) sensors mounted at three different locations near the wing root. Strain acting on the three sensors at different air speeds and angles-of-attack were experimentally obtained in a closed circuit wind tunnel under normal conditions of operation. A function mapping the angle of attack and air speed to the strains on the three sensors was simulated using feedforward neural networks trained using a backpropagation training algorithm. This mapping …

Neuro Emission Controller For Minimizing Cyclic Dispersion In Spark Ignition Engines, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel neural network (NN) controller is developed to control spark ignition (SI) engines at extreme lean conditions. The purpose of neurocontroller is to reduce the cyclic dispersion at lean operation even when the engine dynamics are unknown. The stability analysis of the closed-loop control system is given and the boundedness of all signals is ensured. Results demonstrate that the cyclic dispersion is reduced significantly using the proposed controller. The neuro controller can also be extended to minimize engine emissions with high EGR levels, where similar complex cyclic dynamics are observed. Further, the proposed approach can be applied to control …

Rapid Measurement Of Indoor Mass-Transfer Coefficients, Glenn Morrison, Zhao Ping, Deborah J. Wiseman, Maneerat Ongwandee, Hong Chang, Julie Portman, Shekhar Regmi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, v_t (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss …

A Finite Subelement Generalization Of The Variational Nodal Method, M. A. Smith, Nicholas Tsoulfanidis, E. E. Lewis, G. Palmiotti, T. A. Taiwo

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The variational nodal method is generalized by dividing each spatial node into a number of triangular finite elements designated as subelements. the finite subelement trial functions allow for explicit geometry representations within each node, thus eliminating the need for nodal homogenization. the method is implemented within the Argonne National Laboratory code VARIANT and applied to two-dimensional multigroup problems. Eigenvalue and pin-power results are presented for a four-assembly Organization for Economic Cooperation and Development/Nuclear Energy Agency benchmark problem containing enriched UO2 and mixed oxide fuel pins. Our seven-group model combines spherical or simplified spherical harmonic approximations in angle with isoparametric linear …

Adaptive-Critic-Based Optimal Neurocontrol For Synchronous Generators In A Power System Using Mlp/Rbf Neural Networks, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel optimal neurocontroller that replaces the conventional controller (CONVC), which consists of the automatic voltage regulator and turbine governor, to control a synchronous generator in a power system using a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN). The heuristic dynamic programming (HDP) based on the adaptive critic design technique is used for the design of the neurocontroller. The performance of the MLPN-based HDP neurocontroller (MHDPC) is compared with the RBFN-based HDP neurocontroller (RHDPC) for small as well as large disturbances to a power system, and they are in turn compared …

An Extended Kalman Filter (Ekf) Approach On Fuzzy System Optimization Problem, Nian Zhang, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Optimizing the membership functions of a fuzzy system can be viewed as a system identification problem for a nonlinear dynamic system. Basically, we can view the optimization of fuzzy membership functions as a weighted least-squares minimization problem, where the error vector is the difference between the fuzzy system outputs and the target values for those outputs. The extended Kalman filter algorithm is a good choice to solve this system identification problem, not only because it is a derivative-based algorithm that is suitable to solve the weighted least-squares minimization problem, but also because of its appealing predictor-corrector feature for nonlinear system …

Computational Enhancement Of Genetic Algorithm Via Control Device Pre-Selection Mechanism For Power System Reactive Power/Voltage Control, G. Krost, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the application of a novel and computationally enhances genetic algorithm (GA) for solving the reactive power dispatch problem is presented. In order to attain a significant reduction in the computational time of GA, a systematic procedure of reactive power control device pre-selection mechanism is herein proposed to choose a-priori subsets of the available control devices, which maximally influence buses experiencing voltage limit violations. The GA reactive power dispatch module then accesses such judiciously pre-selected control device candidates to determine their optimal settings. A pragmatic scheme aimed at further curtailing the number of the final control actions entertained …

Dual Heuristic Programming Excitation Neurocontrol For Generators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design of nonlinear optimal neurocontrollers that replace the conventional automatic voltage regulators for excitation control of turbogenerators in a multimachine power system is presented in this paper. The neurocontroller design is based on dual heuristic programming (DHP), a powerful adaptive critic technique. The feedback variables are completely based on local measurements from the generators. Simulations on a three-machine power system demonstrate that DHP-based neurocontrol is much more effective than the conventional proportional-integral-derivative control for improving dynamic performance and stability of the power grid under small and large disturbances. This paper also shows how to design optimal multiple neurocontrollers for …

An Investigation Of The Concept Of Balance In Children Ages 6–9: Logic And Protologic Identifiable In Making Mobiles, Seon Chun

Dissertations and Theses @ UNI

This research was conducted to explore children's construction of protologic (foreshadowing of operations) in the context of experience with balance mobiles in a constructivist setting and to explore the usefulness of making mobiles in promoting children's development of the concept of balance.

The statement of the problem is (a) Can constructivist principles of cognitive development be used to understand children's progress in the course of educational activities involving balance? If so, how? What does the progressive construction of notions about balance look like in children's behaviors? and (b) Does children's understanding of balance improve after experimenting with making mobiles?

The …

Student Perceptions Of Ethics And Professionalism In Computer Science: Does Age, Gender, Or Experience Matter?, James Stuart Bohy

Dissertations and Theses @ UNI

This work explores several factors that impact ethics education in undergraduate computer science, including: the overall understanding of ethics material, any differences between male and female subjects, any differences between traditional age and non-traditional age subjects, and any differences in experience level. Instruments (attitudinal surveys and reflective scenarios) were distributed to four institutions in the Midwest; 74 out of 170 were returned.

Female subjects demonstrated a markedly better ability to distinguish between ethical and unethical behavior in the scenarios (especially in areas where the distinctions were less obvious) and produced higher quality written justifications. There were only 4 attitudinal survey …

Development And Implementation Of The University Of Northern Iowa's “Students First” Capital Campaign: A Case Study, Cornelius Anthony Castain

Dissertations and Theses @ UNI

A case study was conducted of The University of Northern Iowa's Students First 100 million-dollar comprehensive capital campaign. This study examined the predominant forces, activities, and participants associated with employing the capital campaign strategy at a public comprehensive university. When, how, and in what sequence did these major forces, activities, and participants converge to develop and implement the capital campaign? The study also describes major challenges incurred during the campaign cycle. The initial interview questionnaire was adapted from a study by Leonard Moisan (1986) of the University of Virginia's capital campaign. Seventeen people were interviewed including the President, development staff, …

Design And Evaluation Of A Pdf Print Estimating System, Mengtsung Tai

Dissertations and Theses @ UNI

This research consisted of designing and evaluating portable document format (PDF) print estimating system to commercial systems. Taking into account functionality, reliability, standardization, and integration, the conventional design method (Pressman, 1997) was used to develop the print estimating system. Considering the printer's viewpoint, added features make the system function online and offline and compatible with all common computer platforms. After the system was developed, experts and entry-level users evaluated the system for software usability (Nielsen, 2000; Shneiderman, 1998). A total of 26 experts and 38 entry-level users responded to 14 questions about usability in a personal interview survey. Statistical analysis …

The Design And Evaluation Of A Plc-Based Model Predictive Controller For Application In Industrial Food Processes, Bryan T. Griffen

Dissertations and Theses @ UNI

Model Predictive Control (MPC) is a viable control strategy for industrial processes that display relatively large variations in the process variable, have complex process variable interactions, or display a large amount of process deadtime. The objective of using MPC in manufacturing is to reduce overall process variability, the result being an increase in process accuracy, precision and efficiency. This study focused on the implementation of model predictive control techniques on an industrial sugar cooking process. The goal was to implement a successful MPC solution directly on a programmable logic controller (PLC) rather than on a personal computer (PC). Although there …

Power System Basics For Business Professionals In Our Industry, G. Gross, Peter W. Sauer, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

The rapid changes in the business aspects of the electricity industry are making it necessary for engineers to communicate more frequently and more effectively with nontechnical people. With the heightened interest in electric power and energy systems, a broad range of "nonpower" people has expressed a need for a primer on power engineering fundamentals presented in a nontechnical manner. In response, the IEEE Power Engineering Society sponsored the preparation of such a course targeted towards the "business professional." The first offering of this course was in July 2002 as part of the IEEE PES Summer Meeting in Chicago. Power System …

Rate-Based End-To-End Congestion Control Of Multimedia Traffic In Packet Switched Networks, Mingsheng Peng, S. R. Subramanya, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes an explicit rate-based end-to-end congestion control mechanism to alleviate congestion of multimedia traffic in packet switched networks such as the Internet. The congestion is controlled by adjusting the transmission rates of the sources in response to the feedback information from destination such as the buffer occupancy, packet arrival rate and service rate at the outgoing link, so that a desired quality of service (QoS) can be met. The QoS is defined in terms of packet loss ratio, transmission delay, power, and network utilization. Comparison studies demonstrate the effectiveness of the proposed scheme over New-Reno TCP (a variant …