Engineering Commons^™

Hopfield Model For Shortest Path Computation And Routing In Atm Network, Chee Weng Lee

Student Works (2000-2009)

This research focuses on the application of Hopfield neural network and Boltmann machine in solving the shortest path routing problem in the ATM network environment. Hopfield neural network and Boltzmann machine are two types of neural network which are commonly used for solving optimization problem such as the shortest path routing problem. The objectives of this research are to construct a Hopfield neural network and a Boltzmann machine for solving the shortest path routing problem in the ATM network. Both of these two types of neural network are built based on a chosen example of an A TM network. The …

Comparative Performance Of Wastewater Treatment Plants In Three Rubber Glove Manufacturing Plants, Lee Kuan Loh

Student Works (2000-2009)

During the manufacturing of rubber gloves, water is used as wash water at different stages to clean the rubber gloves, thus generating quite a substantial amount of effluent. There are four main sources of effluent. i.e. a) from the glove formers cleaning tank, which collects the acidified water used to clean these formers, b) latex dipping tank, where it collects wash water used to cool the tank during dipping process and the sludge form the tank itself, c) leaching tank, where it collects wash water used to leach out the pollutants from the gloves and lastly d) latex compounding, containing …

Investigation Of Optical Interference Effects In The Generalized Eikonal Formalism, Nyok Fah Thong

Student Works (2000-2009)

In recent studies, the generalized eikonal equation and the equation of continuity had been shown able to describe wave phenomena, which cannot be obtained by simple geometrical optics. The time dependent generalized eikonal equation, derived from the time dependent Maxwell wave equation, is able to describe dispersion and soliton effects. This method was exten4ed to include diffraction, self-trapping and self-focusing in linear and non-linear media for stationary waves. For cases that have no analytical solution, the generalized eikonal equation and the equation of continuity are solved numerically. The solutions are in good agreement with the solutions obtained from the Fresnel-Kirchhoff …

Infared Spectroscopy And Electrical Conductivity Of Copper(Ii) Cinnamate And Iodine-Doped Copper(Ii) Cinnamate, Kumar Krishnan

Student Works (2000-2009)

Copper(II) cinnamate (CC) was prepared from copper(II) acetate monohydrate and cinnamic acid. It was a light-blue powder. The Fourier Transform Infrared (FTIR) spectrum of CC, recorded as potasium bromide (K.Br) disc, indicated the presence of all bonds and functional groups expected of it and showed that it exist as an equal mixture of cis- and trans- isomers. The conductivity of CC at room temperature was 5.22 x 10⁻¹¹Scm⁻¹. It showed metallic behaviour in the temperature range 78-300 K, and its conduction mechanism obeyed Mott's variable range hopping (VRH) model in the same temperature range. The density of states at Fermi …

Analysis And Synthesis Of Primary Side Cycle By Cycle Control Of Isolated Flyback Converters, Radoslaw Nalepa

Theses

This work presents the analysis and design of an isolated flyback converter, without feedback from the load side. The converter is controlled from the primary side using the switch voltage and innovative control circuit topologies.

A detail study of the flyback circuit is undertaken including all known parasitics. Besides the standard parasitics, for example the capacitor resistive effect, other more subtle effects are included in the model development such as inter coil couplingj source capacitance etc. Development of these models has provided information about circuit simplifications without losing accuracy of the model. As a consequence of this model development, it …

Remote Monitoring System, Chin Kee Tan

Student Works (2000-2009)

Research is conducted to analysis and evaluate about the Remote Monitoring System. The details process of developing the Remote Monitoring System will be discussed throughout whole section of this project. The primary objective of this project is to explore on how Remote Monitoring CCTV process work as well as the application area used in Remote Monitoring CCTV system. This project involves creating a real time monitoring video camera system as a prototype. The developer will perform the development of the system according to system development life cycle. Stages of the system development life cycle for developing the remote monitoring software …

Experimental Studies With Continually Online Trained Artificial Neural Network Identifiers For Multiple Turbogenerators On The Electric Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing complexity of a modern power grid highlights the need for advanced system identification techniques for effective control of power systems. This paper provides a new method for nonlinear identification of turbogenerators in a 3-machine 6-bus power system using online trained feedforward neural networks. Each turbogenerator in the power system is equipped with a neuro-identifier, which is able to identify its particular turbogenerator and the rest of the network to which it is connected from moment to moment, based on only local measurements. Each neuro-identifier can then be used in the design of a nonlinear neurocontroller for each turbogenerator …

Millimeter Wave Oscillator Based Dielectric Hemisphere With Cylinder Shield, Sergey Kharkovsky, A. E. Kogut, V. V. Kutuzov

Electrical and Computer Engineering Faculty Research & Creative Works

The purpose of this paper is the investigation of the main Gunn diode oscillator characteristics with a hemispherical dielectric resonator which is shielded by a metal cylinder. The frequency, output power and electronic tuning of frequency, the steepness of which allows one to estimate the frequency stability in relation to the parasitic change of the Gunn diode voltage, and their comparative analysis with the characteristics of generation in a similar open dielectric resonator.

Organizational Change, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Volume Management In San Environment, Chang-Soo Kim, Gyoung-Bae Kim, Bum-Joo Shin

Electrical and Computer Engineering Faculty Research & Creative Works

Logical volume managers have long been key components of a storage system. Their key features are creation of logical or virtual views of physical storage devices and support for various software RAID levels. These make it possible to overcome the limits to capacity, availability and performance of a physical storage device. Most logical volume managers are operated in a single system environment. They are not adequate for SAN (storage area network) environments where several hosts share and access a logical volume at the same time. Some recent logical volume managers are run in a multi-host environment. However, they cannot support …

A Fast Evanescent Wave Algorithm, W. C. Chew, L. (Lijun) J. Jiang, S. Velamparambil

Electrical and Computer Engineering Faculty Research & Creative Works

Description of a fast evanescent wave algorithm was presented that traded off the use of memory for increasing the speed. The use of the buffer boxes was avoided by the algorithm which increased its speed. An efficient method to derive or store the evanescent wave spectrum from the propagating wave spectrum was studied.

Robust State Dependent Riccati Equation Based Guidance Laws, S. N. Balakrishnan, Ming Xin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A robust state dependent Riccati equation based guidance/control is investigated in this study. In order to have a better design tool in terms of required interceptor accelerations, the target intercept geometry is formulated in a set of polar coordinates. With this formulation, we formulate a cost function with state dependent weights. In this study, we investigate the effects of such cost functions on the levels of interceptor accelerations. We also synthesize a neural network based extra controller to achieve the robustness in the presence of the target acceleration. In this manner, we will not need target acceleration estimation explicitly in …

An Optimal Control Based Treatment Strategy For Parturient Paresis Using Neural Networks, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An optimal online feedback treatment strategy is developed for the parturient paresis of cows, based on nonlinear optimal control theory. A limitation in the development of an existing mathematical model for calcium homeostasis is addressed and the model is extended to incorporate control inputs. An optimal feedback controller is synthesized for the nonlinear system using neural networks. Though the main aim of this paper is to solve the biomedical control problem, the methodology presented in this paper is a general computational tool, which can be applied to solve a fairly general class nonlinear optimal control problems.

Robust State Dependent Riccati Equation Based Robot Manipulator Control, Ming Xin, S. N. Balakrishnan, Zhongwu Huang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We present a new optimal control approach to robust control of robot manipulators in the framework of state dependent Riccati equation (SDRE) technique. To treat this highly nonlinear control system, we formulate it as a nonlinear optimal regulator problem. SDRE technique was used to synthesize an optimal controller to this class of robot control problem. We also synthesize a neural network based extra controller to achieve the robustness in the presence of the parameter uncertainties. A typical two-link robot position control problem was studied to show the effectiveness of SDRE approach and robust extra control design to robotic application.

Method Of Creating Ultra-Fine Particles Of Materials Using A High-Pressure Mill, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

A method for creating ultra-fine particles of material using a high-pressure mill is described. The method includes placing a material in a first chamber and subjecting the material to a high-pressure liquid jet to divide it into particles. These particles are then transferred to a second chamber in which they are subjected to cavitation to further divide the particles into relatively smaller particles. These relatively smaller particles are then transferred to a third chamber, in which the particles collide with a collider to still further divide them into ultra-fine particles of the material. The mill of the present invention includes …

Computer Viruses, S. R. Subramanya, Natraj Lakshminarasmhan

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Purification And Characterization Of Crystallins By Aqueous Two-Phase Extraction, Ondrea Bermudez, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Crystallins are a family of water-soluble proteins that constitute up to 90% of the water-soluble proteins in mammalian eye lenses. We present in this paper an alternative purification method for these proteins using polyethylene glycol/dextran aqueous two-phase extraction. Under the appropriate conditions, we were able to recover the γ-crystallin fraction essentially free of the remaining proteins. High concentrations of salt at a neutral pH maximize the recovery of γ-crystallins in the top phase and minimize the contamination by the other proteins present in the lenses. The proposed protocol decreases the separation time by about 50%. The complex partition behavior observed …

Dynamics Of Polyacrylates In Concentrated Chloroform Solutions, Frank D. Blum, Raj B. Durairaj

Chemistry Faculty Research & Creative Works

The dynamics of polymers in polymer solutions have not been probed in great enough detail to provide a coherent picture of the behavior of these polymers, especially in more concentrated solutions. To help understand this behavior further, we have prepared a series of backbone-labeled polymers including poly(n-butyl acrylate)-d1 (PNBA). These provide a basis for comparison of the behavior among a group of related polymers. The dynamics have been probed by using deuterium relaxation times. Since the relaxation times are relatively fast and the quadrupolar relaxation mechanism is well understood, data from this technique provide a convenient means for comparison of …

Glass Transition Behavior Of Pmma Thin Films, Moses T. Kabomo, Frank D. Blum

Chemistry Faculty Research & Creative Works

In the last decade there has been an increased interest in the study of the properties of supported thin polymer films. This has been prompted by the incorporation of thin films into device applications and many other technologies. Although not without controversy, a large body of experimental work indicates departures from bulk behavior by thin films. Strong evidence from both theoretical and experimental work shows that the interaction of polymer with a substrate alters the polymer conformation and mobility. A variety of techniques has been employed to probe the mobility of thin supported polymer films. Some of these techniques indirectly …

Graduated Segmental Mobility In Polymer Layers On Silica, Frank D. Blum, Crystal E. Porter, Wuu-Yung Lin

Chemistry Faculty Research & Creative Works

The behavior of thin polymer layers on oxide substrates has gotten a great deal of attention as the size of materials, and hence polymer films, has gotten smaller. Indeed, the properties of adsorbed polymers are such that they can be different from those of bulk polymers, especially when the films are very thin. A wide variety of studies have been made on adsorbed polymers and sometimes the results seem contradictory. One of the properties often measured in thin films is the apparent glasstransition temperature, Tg. In principle, many techniques are sensitive to phenomenological changes occurring around Tg and, therefore, can …

Thermal Analysis Of Ultrathin Ps-R-Pmma Copolymer Films On Silica, Bing Zhang, Frank D. Blum

Chemistry Faculty Research & Creative Works

Composite materials represent a major part of man-made materials that are used in many applications. The interaction of polymers with surfaces plays a crucial role in the final properties of these materials and, by understanding the surface processes and adsorption mechanisms, better systems can be designed. Therefore, the behavior of polymer molecules at interfaces has been the topic of many studies in recent years and a rough picture has been obtained. Keddie et al. Obtained experimental results showing the dependence of the glass transition temperature (Tg) on the thickness of supported polystyrene films using ellipsometry. Later, they also investigated supported …

Re-Examination Of The Crypto-Steady Pressure-Exchanger (Virtual Turbomachine), T. Scott, David W. Riggins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A crypto-steady pressure-exchanger (rotating center body ejecting fluid in a supersonic flow field) is investigated based on fundamental fluid dynamic principles. The results are then compared to computational fluid dynamic (CFD) simulations of a simplified device. On the basis of this comparison the device studied is correctly classified as an unsteady ejector instead of a type of turbomachinery. Entropy gains (total pressure losses) associated with the complex fluid-fluid and fluid-center body interactions are shown to be greater than total pressure gains due to work addition. Compared to a steady ejector, the virtual turbomachine shows increased entrainment (mixing) of the main …

A Numerical Study Of Automotive Gas Tank Filler Pipe Two Phase Flow, R. Banerjee, Kakkattukuzhy M. Isaac, L. Oliver, W. Breig

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Automotive refueling is gaining greater importance because fuel vapors released during refueling are believed to increase ozone levels in urban areas. As a step towards On-Board Refueling Vapor Recovery (ORVR) designs, vapor generation and transport during refueling needs to be understood to develop recovery techniques. The objective of the present study is to understand the fluid flow inside the automotive gas tank filler pipe using commercially available Computational Fluid Dynamics (CFD) software. This effort is expected to yield detailed flow field information, including air entrainment. The phenomena of well-back, the process of fuel flooding the filler pipe and flowing backwards …

Art/Sofm: A Hybrid Approach To The Tsp, Narayan Vishwanathan, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

We present a new method of solving large scale travelling salesman problem (TSP) instances using a combination of adaptive resonance theory (ART) and self organizing feature maps (SOFM). We divide our algorithm into three phases: phase one uses ART to form clusters of cities; phase two uses a novel modification of the traditional SOFM algorithm to solve a slight variant of the TSP in each cluster of cities; and phase three uses another version of the SOFM to link all the clusters. The experimental results show that our algorithm finds approximate solutions which are about 13% longer than those reported …

Challenge Problem Update: Peec And Mom Analysis Of A Pc Board With Long Wires Attached, H. Wang, Todd H. Hubing, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

At the 2000 IEEE International Symposium on EMC, a paper was presented by Y. Ji et al. (paper appears in 2001 proceedings) that compared the application of PEEC and MOM techniques to the analysis of one of the EMC Society/Applied Computational Electromagnetics Society special challenge problems. Good agreement was obtained between the two codes at 2 out of the 3 measurement ports. At that time, no definite explanation was provided for the discrepancy at the third port. This paper shows that the problem was (at least partly) related to assumptions made about the signal source

Study Of Dynamics And Mechanism Of Metal-Induced Silicon Growth, Elena A. Guliants, Wayne A. Anderson

Electrical and Computer Engineering Faculty Publications

The present study addresses the mechanism of metal-induced growth of device-quality silicon thin films. Si deposition was performed by magnetron sputtering on a 25-nm-thick Ni prelayer at 525–625 °C and yielded a continuous, highly crystalline film with a columnar structure. A Ni disilicide intermediate layer formed as a result of the Ni reaction with Si deposit provides a sufficient site for the Si epitaxial growth because lattice mismatch is small between the two materials. The reaction between Ni and Si was observed to progress in several stages. The NixSiy phase evolution in a Ni:Si layer was studied by x-ray photoelectron …

Resonant Energy Transfer From Argon Dimers To Atomic Oxygen In Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz

Bioelectrics Publications

The emission of atomic oxygen lines at 130.2 and 130.5 nm from a microhollow cathode discharge in argon with oxygen added indicates resonant energy transfer from argon dimers to oxygen atoms. The internal efficiency of the vacuum-ultraviolet (VUV) radiation was measured as 0.7% for a discharge in 1100 Torr argon with 0.1% oxygen added. The direct current VUV point source operates at voltages below 300 V and at current levels of milliamperes.

Self-Consistent Simulations Of Electroporation Dynamics In Biological Cells Subjected To Ultrashort Electrical Pulses, R. P. Joshi, Q. Hu, R. Aly, K. H. Schoenbach, H. P. Hjalmarson

Bioelectrics Publications

The temporal dynamics of electroporation of cells subjected to ultrashort voltage pulses are studied based on a coupled scheme involving the Laplace, Nernst-Plank, and Smoluchowski equations. A pore radius dependent energy barrier for ionic transport, accounts for cellular variations. It is shown that a finite time delay exists in pore formation, and leads to a transient overshoot of the transmembrane potential V_mem beyond 1.0 V. Pore resealing is shown to consist of an initial fast process, a 10⁻⁴s delay, followed by a much slower closing at a time constant of about 10 ⁻¹s. This establishes a …

Using A Rapid Prototyping Machine In The Integrated Kinematics, Dynamics, And Machine Design Lab, Wieslaw M. Szydlowski

Department of Mechanical and Materials Engineering: Faculty Publications

According to a recent trend, two different labs - the Machine Design lab, and Kinematics, and Dynamics lab are combined into one integrated lab. The time students spend on their projects is halved. To save the quality of undergraduate education, an ew methodology has to be developed. The paper explains the methodology developed by the author while teaching the integrated Kinematics, Dynamics, and Machine Design Lab (MECH 488) at the Mechanical Engineering Department of the University of Nebraska-Lincoln.

The objective of the aforementioned lab is to teach the students, who have no design experience, how to select proper tools (firom …

Associating Nodes With Routers In K-Ary M-Way Interconnection Networks, Aya Hassan Saad

Archived Theses and Dissertations

No abstract provided.