Electrical and Computer Engineering Commons^™

The Study On Fluorescence Characteristics Of Chlorella Spp: Ph Influence On Culture, Retno Wigajatri P., Andrianto Handojo, Hendrik Kurniawan, N. B. Prihantini

Makara Journal of Technology

The Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture. Experiments for measuring the fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser of energy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration range from 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationship with the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at the starting culture influenced the …

The Performance Analysis Of A Unicast Network When Two Protocols, Sctp (Stream Control Transmission Protocol) And Tcp (Transmission Control Protocol) Coexist In The Network, Bagio Budiardjo, Michael Thiotrisno

Makara Journal of Technology

This paper elaborates the performance analysis of a unicast network when two protocols, SCTP (Stream Control Transmission Protocol) and TCP (Transmission Control Protocol) coexist in the network. These two protocols are tested using File Transfer Protocol (FTP) and Constant Bit Rate (CBR) based traffic. From the simulations, it could be concluded that SCTP could achieve better throughput compared to TCP in both FTP and CBR based traffic, with sufficiently high fairness index of both intrafairness and interfairness. The increase of simulation time yields to the increase and relatively stable network performance. The increase of the number of sessions of small …

Revisiting The Fresnel Coefficients For Uniform Plane Wave Propagation Across A Nonchiral, Reciprocal And Chiral, Nonreciprocal Interface, Monish Ranjan Chatterjee, Sumit Nema

Electrical and Computer Engineering Faculty Publications

The problem of EM wave propagation in non-reciprocal chiral media has been studied by several investigators. In a recent approach, a dual-transform technique has been developed to study the problem of such propagation under paraxial and slow-envelope variation conditions.

In this paper, we first outline some of the results obtained using the dual transform technique for arbitrary boundary conditions within the left boundary of a semi-infinite, non-reciprocal chiral medium for a uniform plane wave, and a fundamental Gaussian-profiled beam. Next, we explore the problem of a uniform EM wave incident at an oblique angle at an interface between a reciprocal, …

Spice Model Libraries For Via Transitions, Shaofeng Luan, Giuseppe Selli, Jun Fan, Mauro Lai, James L. Knighten, Norman W. Smith, Ray Alexander, Giulio Antonini, Antonio Ciccomancini, Antonio Orlandi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure of building SPICE models for signal via transitions between printed circuit board layers is presented in this paper. The method of extracting parameters of SPICE models from full-wave simulation tool is demonstrated. Then the validity of SPICE models is studied by comparing the solution from SPICE model with that from the full-wave simulation.

Esd Excitation Model For Susceptibility Study, Federico Centola, David Pommerenke, Kai Wang, Thomas Van Doren, Spartaco Caniggia

Electrical and Computer Engineering Faculty Research & Creative Works

The paper provides a simplified model of a known ESD generator that allows modeling the ESD impulses (current and fields) in CST-Microwave Studio. The model is suitable for simulating the excitation of structures by ESD, but it is not intended to predict the fields and current of an ESD generator for its development purpose. The aim is to simultaneously model the ESD generator and a susceptible structure with as few details as possible but to obtain as good a match on current and fields as possible.

Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A finite-difference time-domain (FDTD) method capable of attaching rectangular computational domains is proposed herein. The aim of this approach is to reduce the size of computational domain according to the geometry of the modeled structure so as to reduce the simulation time with keeping precision of the result in an acceptable range. A multigrid algorithm is applied on the attaching interface between two rectangular domains so that different resolution can be achieved in different domains.

Spontaneous Coherent Pulsations In 3.39-M He–Ne Standing-Wave Laser Oscillators, Pitak Chenkosol, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Spontaneous pulsations similar to the type discovered in 3.51-μm Xe laser oscillators were reported several years ago in 3.39-μm He–Ne lasers, but no numerical interpretation of the He–Ne data has been given. The model for the Xe laser instability is adapted here to the He–Ne system, and the results include direct comparisons between theoretical calculations and published experimental data. Good agreement is obtained for the instability threshold, the pulsation frequencies, and many other features; and unmeasured but potentially useful pulsation characteristics are also readily obtained from the model.

Anticipating Emi Using Transfer Functions And Signal Integrity Information, Chen Wang, James L. Drewniak, Jim Nadolny

Electrical and Computer Engineering Faculty Research & Creative Works

Discontinuities in a circuit can lead to signal integrity as well as EMI problems. A method, which efficiently combines full-wave tools and circuit simulators, is proposed herein to analyze the coupling at discontinuities. The proposed method may be applied to practical engineering designs.

Anticipating Vehicle-Level Emi Using A Multi-Step Approach, Geping Liu, David Pommerenke, James L. Drewniak, Richard W. Kautz, Chingchi Chen

Electrical and Computer Engineering Faculty Research & Creative Works

A multi-step procedure for anticipating vehicle-level EMI is proposed in this paper. This approach uses multi-conductor transmission line (MTL) modeling to calculate current distributions along the cable bundle. A common-mode circuit is extracted from the MTL modeling, and is employed in full-vehicle full-wave modeling to determine radiation and interference. In this paper, mode-dispersion and mode-conversion phenomena are investigated, and the ambiguous definitions of the common-mode voltage and common-mode impedance are discussed.

Real-Time Dual Heuristic Programming-Based Neurocontroller For A Turbogenerator In A Multimachine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Based on Dual Heuristic Programming (DHP), a real-time implementation of a neurocontroller for excitation and turbine control of a turbogenerator in a multimachine power system is presented. The feedback variables are completely based on local measurements. Simulation and real-time hardware implementation on a three-machine system demonstrate that the DHP neurocontroller is much more effective than conventional PID controllers, the automatic voltage regulator, power system stabilizer and the governor, for improving dynamic performance and stability under small and large disturbances.

Modeling Of Short-Gap Esd Under Consideration Of Different Discharge Mechanisms, S. Bonisch, Wilifried Kalkner, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

Simulation of short gap electrostatic discharge (ESD) in air needs to consider two processes: a surface process and an avalanche process. Two models, a phenomenological approach and a physical approach, considering both discharge processes are proposed for the simulation of short-gap ESD. A new mathematical derivation for the modeling of the surface process is discussed in detail. A new technique to combine surface and avalanche process models is described. Measured and simulated data based on short-gap ESD are provided and compared. Advantages and drawbacks of the proposed models are discussed. Attained results should help to optimize ESD testing.

Reconstruction Of The Parameters Of Debye And Lorentzian Dispersive Media Using A Genetic Algorithm, Jianmin Zhang, Marina Koledintseva, Giulio Antonini, James L. Drewniak, Konstantin Rozanov, Antonio Orlandi

Electrical and Computer Engineering Faculty Research & Creative Works

A method for reconstruction of the parameters of the Debye or Lorentzian dispersive media is proposed. In this method, S-parameters of a simple parallel-plate fixture filled with the dispersive medium are measured and modeled using the transmission line equations, provided a single TEM mode propagating in this parallel-plate waveguide. The genetic algorithm is used for searching the parameters of the dispersive medium by means of minimizing the discrepancy between the measured and modeled S-parameters. The results are verified using the full-wave FDTD modeling technique.

Impact Of Esd Generator Parameters On Failure Level In Fast Cmos System, Kai Wang, David Pommerenke, Kai Xiao, Ponniah Ilavarasan, Mike Schaffer, Ramachandran Chundru, Jiu Sheng Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Electrostatic discharge (ESD) generators are used for testing the robustness of electronics towards ESD. Most generators are built in accordance with the IEC 61000-4-2 specifications. It is shown that the voltage induced in a small loop correlates with the failure level observed in an ESD failure test on the systems comprising fast CMOS devices, while rise time and current derivative of the discharge current did not correlate well. The electric parameters are compared for typical and modified ESD generators and the effect on the failure level of fast CMOS electronics is investigated. The consequences of aligning an ESD standard with …

Memory Dimm Dc Power Distribution Analysis And Design, Jingkun Mao, Chen Wang, Giuseppe Selli, Bruce Archambeault, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

DC power bus design is critical in meeting signal integrity (SI) and electromagnetic compatibility (EMC) requirements. A suitable modeling tool is beneficial to evaluate power bus design and develop design guidelines. This paper discusses difficulties met in evaluating the power distribution design on a dual inline memory module (DIMM) board, such as a power bus with arbitrary shape, parasitic inductance associated with vias, and so on. Moreover, some solutions are given in this paper. A simple cavity model with a segmentation method was employed to model a power bus with irregular shapes. The partial element equivalent circuit (PEEC) technique was …

Modeling Issues For Full-Wave Numerical Emi Simulation, Michael A. Cracraft, Xiaoning Ye, Chen Wang, Sandeep K. R. Chandra, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

In electromagnetic modeling, agreement between modeling and measurements is a common goal. There are questions that define every model. What is to be modeled? How is it going to be modeled? At what scale is it to be modeled? Through sample results and discussion, this paper addresses some general and some specific elements of model veracity. Through determination, numerical models can certainly be pushed to match any measured results. However, in the end the question that this paper addresses is not necessarily "How good can this model be?" as it is "Is this model good enough?".

Online Identification Of Turbogenerator's Dynamics Using A Neuro-Identifier, Wenxin Liu, Ganesh K. Venayagamoorthy, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing complexity of modern power systems highlights the need for effective system identification techniques for the successful control of power system. This paper proposes a robust continually online trained neuroidentifier to predict the outputs of turbogenerator - terminal voltage and speed deviation. The inputs to the neuro-identifier are the changes of the plant's outputs and plant's inputs. It overcomes the drawback of calculating deviation signals from reference signals for different operating points in previous work. Simulation results show that the neuro-identifier can provide accurate identification under different operating conditions. Furthermore, the neuro-identifier can learn the dynamics of the system …

Fdtd Modeling Of Isotropic Dispersive Magnetic Materials, Jing Wu, Marina Koledintseva, James L. Drewniak, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

Numerical analysis using the finite-difference time-domain (FDTD) algorithm with a piecewise linear recursive convolution (PLRC) procedure for linear isotropic dispersive magnetic materials is presented. The frequency dependence of susceptibility used for this algorithm is represented in Debye, narrowband Lorentzian, and wideband Lorentzian forms, depending on the ratio of the resonance frequency and the resonance line width. Some numerical examples along with measurements are provided.

Large-Scale Inverse Ku-Band Backscatter Modeling Of Sea Ice, David G. Long, Quinn P. Remund

Faculty Publications

Polar sea ice characteristics provide important inputs to models of several geophysical processes. Microwave scatterometers are ideal for monitoring these regions due to their sensitivity to ice properties and insensitivity to atmospheric distortions. Many forward electromagnetic scattering models have been proposed to predict the normalized radar cross section (σ˚) from sea ice characteristics. These models are based on very small scale ice features and generally assume that the region of interest is spatially homogeneous. Unfortunately, spaceborne scatterometer footprints are very large (5-50 km) and usually contain very heterogeneous mixtures of sea ice surface parameters. In this paper, we use scatterometer …

Quantifying The Effects On Emi And Si Of Source Imbalances In Differential Signaling, Chen Wang, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Imbalances in differential signaling can introduce common-mode components, resulting in signal integrity (SI) problems as well as EMI problems. Three-port mixed-mode S-parameters are employed to quantify the impacts on EMI. The EMI problems caused by delay skew and slew rate skew are investigated.

Design And Development Of A Low-Cost High Range Resolution X-Band Radar, Paul C. Cantu

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

Synthetic Aperture Radar (SAR) is one of the main tools for microwave remote sensing because of its multi-dimensional high resolution characteristics and the capability to operate in nearly all weather conditions, day and night. The University of Nebraska-Lincoln (UNL) initiated the design and development of a low-cost airborne SAR in January 2001 to support our Airborne Remote Sensing Program. The objectives of this project are separated into various evolutionary stages. This thesis will focus on the initial phase of design and construction of an X-band high range resolution radar (HRR) using basic RF /microwave and digital components. The following stages …

Modeling Electromagnetic Wave Propagation In Electrically Large Structures, Jon Wallace

Theses and Dissertations

Existing unified numerical electromagnetic methods are often unable to analyze electrically large structures due to the amount of memory and processing power required, necessitating approximate analyses with limited applicability. In this research a hybrid modeling methodology is adopted to solve these complex problems more efficiently than unified numerical methods and more accurately than analytical methods. Electromagnetic modeling problems are divided into two or more levels of scale. Each level analyzes a specific level of detail and only promotes the required information to the next level. The method is demonstrated by successful application to three important problems: (1) remote sensing of …

Cross-Layer Protocols Optimized For Real-Time Multimedia Services In Energy-Constrained Mobile Ad Hoc Networks, William S. Hortos

Electrical Engineering and Computer Science Faculty Publications

The optimization of cross-layer protocols for real-time multimedia services in energy-constrained mobile ad hoc networks (MANET) was presented. The cross-layer optimization was based on stochastic dynamic programming conditions derived from time-dependent models of MANET packet flows. The performance of the optimized cross-layer protocols was also determined by using dynamic programming conditions.

Real-Time Adaptive Cancellation Of Satellite Interference In Radio Astronomy, Andrew Joseph Poulsen

Theses and Dissertations

Radio astronomy is the science of observing the heavens at radio frequencies, from a few kHz to approximately 300 GHz. In recent years, radio astronomy has faced a growing interference problem as radio frequency (RF) bandwidth has become an increasingly scarce commodity. A programmable real-time DSP least-mean-square interference canceller was developed and demonstrated as a successful method of excising satellite down-link signals from both an experimental platform at BYU, and the Green Bank Telescope at the National Radio Astronomy Observatory in West Virginia. A performance analysis of this cancellation system in the radio astronomy radio frequency interference (RFI) mitigation regime …

Micro-Genetic Algorithm Design Of Hybrid Conventional Waveguide And Photonic Crystal Structures, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We previously proposed the hybrid integration of photonic crystals (PhCs) and conventional index-guided waveguides (CWGs) as a potentially attractive method of realizing compact waveguide elements for large-scale planar lightwave circuits (PLCs). We now examine 90-deg bends and beamsplitters in PhC/CWG structures in which the waveguide core has a high refractive index (3.25) and yet a low refractive index contrast (1.54%) with the clad material. A PhC structure composed of a triangular or square array of air holes is placed at the intersection of input and output waveguides to obtain high efficiency 90-deg bends. We find that diffraction from the boundary …

An Adaptive Neural Network Identifier For Effective Control Of A Static Compensator Connected To A Power System, Salman Mohagheghi, Jung-Wook Park, Ganesh K. Venayagamoorthy, Mariesa Crow, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

A novel method for nonlinear identification of a static compensator connected to a power system using continually online trained (COT) artificial neural networks (ANNs) is presented in this paper. The identifier is successfully trained online to track the dynamics of the power network without any need for offline data and can be used in designing an adaptive neurocontroller for a static compensator connected to such system.

Analytical Ise Calculation And Optimum Control System Design, Tony Kealy, Aidan O'Dwyer

Conference papers

Abstract – In control system theory, a performance index is a quantitative measure of the performance of a system and is chosen so that emphasis is given to the important system parameters. In this paper, the authors demonstrate two methods to determine analytically the Integral of the Square of the Error (ISE) performance index value for a first-order-plus-dead-time (FOPDT) process model under PI control. The ability of proportional/integral (PI) and proportional/integral/derivative (PID) controllers to compensate most practical industrial processes has led to their wide acceptance in industrial applications. The most direct way to set up PI/PID controller parameters is the …

A Ram-Based Neural Network For Collision Avoidance In A Mobile Robot, Qiang Yao, Daryl G. Beetner, Donald C. Wunsch, Bjorn Osterloh

Electrical and Computer Engineering Faculty Research & Creative Works

A RAM-based neural network is being developed for a mobile robot controlled by a simple microprocessor system. Conventional neural networks often require a powerful and sophisticated computer system. Training a multi-layer neural network requires repeated presentation of training data, which often results in very long learning time. The goal for this paper is to demonstrate that RAM-based neural networks are a suitable choice for embedded applications with few computational resources. This functionality is demonstrated in a simple robot powered by an 8051 microcontroller with 512 bytes of RAM. The RAM-based neural network allows the robot to detect and avoid obstacles …

Neuroidentification Of System Parameters For The Shunt & Series Branch Control Of Upfc, Ganesh K. Venayagamoorthy, Radha P. Kalyani, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

The crucial factor affecting the modern power systems today is load flow control. The unified power flow controller (UPFC) forms an affective means for controlling the power flow. The UPFC consists of shunt and series inverters which are conventionally controlled using linear controllers. This paper presents the design of neuroidentifiers that identify the system parameters that determine the UPFC controller outputs one-time step ahead thus, making the pathway for the design of adaptive neurocontrollers. Two neuroidentifiers are used for identifying the nonlinear dynamics of power system and UPFC, one neuroidentifier for the shunt inverter and the other for the series …

Vertebra Shape Classification Using Mlp For Content-Based Image Retrieval, Sameer K. Antani, L. Rodney Long, George R. Thoma, R. Joe Stanley

Electrical and Computer Engineering Faculty Research & Creative Works

A desirable content-based image retrieval (CBIR) system would classify extracted image features to support some form of semantic retrieval. The Lister Hill National Center for Biomedical Communications, an intramural R&D division of the National Library for Medicine (NLM), maintains an archive of digitized X-rays of the cervical and lumbar spine taken as part of the second national health and nutrition examination survey (NHANES II). It is our goal to provide shape-based access to digitized X-rays including retrieval on automatically detected and classified pathology, e.g., anterior osteophytes. This is done using radius of curvature analysis along the anterior portion, and morphological …

Automatic Classification Of African Elephant (Loxodonta Africana) Follicular And Luteal Rumbles, Michael T. Johnson, Patrick J. Clemins

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

Recent research in African elephant vocalizations has shown that there is evidence for acoustic differences in the rumbles of females based on the phase of their estrous cycle (1). One reason for these differences might be to attract a male for reproductive purposes. Since rumbles have a fundamental frequency near 10Hz, they attenuate slowly and can be heard over a distance of several kilometers. This research exploits differences in the rumbles to create an automatic classification system that can determine whether a female rumble was made during the luteal or follicular phase of the ovulatory cycle. This system could be …