Engineering Commons^™

Viewing The Learning Process: Assessment Via Usability Testing, Vicki M. Eller, Steve Eugene Watkins, Richard H. Hall

Business and Information Technology Faculty Research & Creative Works

Learning through Computer-Based Activities Provides a Multi-Modal Approach in Which the User Can Select the Educational Media and Process. Effective Development of These Activities Requires an Understanding of User Interactivity. Traditional Assessment, Such as Test Scores and Subjective Surveys, Looks at End Results and Attitudes. This Method Does Not Monitor the Learning Process. in Particular Developer Needs to Accommodate Diverse Usage Preferences and Choices. Hence, Assessment Should Involve Usability Measures that Are Quantitative and Qualitative. Usability Testing Records Usage Patterns and User Reactions. a Usability Laboratory Was Created at the University of Missouri-Rolla. It is Supplements the Traditional Assessment for …

Modeling And Analysis Of Soft-Test/Repair For Ccd-Based Digital X-Ray Systems, Byoungjae Jin, Nohpill Park, Koshy M. George, Minsu Choi, Mark B. Yeary

Electrical and Computer Engineering Faculty Research & Creative Works

Modern X-ray imaging systems evolve toward digitization for reduced cost, faster time-to-diagnosis, and improved diagnostic confidence. For the digital X-ray systems, charge coupled device (CCD) technology is commonly used to detect and digitize optical X-ray image. This paper presents a novel soft-test/repair approach to overcome the defective pixel problem in CCD-based digital X-ray systems through theoretical modeling and analysis of the test/repair process. There are two possible solutions to cope with the defective pixel problem in CCDs: one is the hard-repair approach and another is the proposed soft-test/repair approach. Hard-repair approach employs a high-yield, expensive reparable CCD to minimize the …

Melanoma And Seborrheic Keratosis Differentiation Using Texture Features, Srinivas V. Deshabhoina, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss, Subhashini K. Srinivasan

Chemistry Faculty Research & Creative Works

Purpose: To explore texture features in two-dimensional images to differentiate seborrheic keratosis from melanoma.

Methods: A systematic approach to consistent classification of skin tumors is described. Texture features, based on the second-order histogram, were used to identify the features or a combination of features that could consistently differentiate a malignant skin tumor (melanoma) from a benign one (seborrheic keratosis). Two hundred and seventy-one skin tumor images were separated into training and test sets for accuracy and consistency. Automatic induction was applied to generate classification rules. Data analysis and modeling tools were used to gain further insight into the feature space. …

A Four-Level Crossing Dc/Dc Converter Based Drive System, X. Kou, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a novel crossing front-end dc/dc converter for a four-level drive system which provides a voltage boost as well as dc capacitor bank voltage regulation. The primary advantage of the proposed converter is that it simplifies the control of the four-level diode-clamped inverter since capacitor voltage balancing is not required by the inverter control. Furthermore, the inverter modulation index can be varied up to its physical limitation. An average-value model of the converter is derived and used for insight and analysis of the converter operation. Detailed simulations of the four-level drive system demonstrate the effectiveness of the proposed …

Design And Characterization Of Null Convention Self-Timed Multipliers, Satish K. Bandapati, Scott C. Smith, Minsu Choi

Electrical and Computer Engineering Faculty Research & Creative Works

Self-timed multipliers, designed using the delay-insensitive null convention logic (NCL) paradigm, were analyzed. NCL require less power, generate less noise, produce less electromagnetic interference, and allow easier reuse of components. Simulation results show a large variance in circuit performance in terms of power, area, and speed. NCL paradigm also represent bit-serial, iterative, and fully parallel multiplication architectures. They reduce the effort required to ensure correct operation under all timing scenarios, compared to equivalent synchronous designs.

Configuration For Micro Ph Sensor, Young-Jin Kim, Young-Chul Lee, Byung-Ki Sohn, Chang-Soo Kim, Jung-Hee Lee

Electrical and Computer Engineering Faculty Research & Creative Works

A fully integrated pH sensor with a built-in reference electrode is proposed. An iridium oxide microelectrode and a pH-insensitive field-effect transistor are used as a pH sensor and a reference electrode, respectively. The sensitivity of the proposed device matches well with the estimated value to within 0.3 mV/pH deviation.

Electromagnetic Compatibility Issues In Mobile Computing, Antonio Orlandi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Suitability Of Pulse Train™, A Novel Digitally Implemented Real-Time Control Technique, For Bifred Converter, Mehdi Ferdowsi, Ali Emadi, Mark Telefus, Anatoly Shteynberg

Electrical and Computer Engineering Faculty Research & Creative Works

Pulse Train^TM, a new control scheme, is presented and applied to a BIFRED converter operating in discontinuous conduction mode (DCM), which avoids the light-load high-voltage stress problem. In contrast to the conventional control techniques, the principal idea of Pulse Train is to regulate the output voltage using a series of high and low energy pulses generated by the current of the inductor. In this paper, applicability of the proposed technique to both the input and magnetizing inductances of BIFRED converter is investigated. Analysis of BIFRED converter operating in DCM as well as the output voltage ripple estimation are …

Modeling And Analysis Of Fault Tolerant Multistage Interconnection Networks, Minsu Choi, Nohpill Park, Fabrizio Lombardi

Electrical and Computer Engineering Faculty Research & Creative Works

Performance and reliability are two of the most crucial issues in today's high-performance instrumentation and measurement systems. High speed and compact density multistage interconnection networks (MINs) are widely-used subsystems in different applications. New performance models are proposed to evaluate a novel fault tolerant MIN arrangement, thereby assuring performance and reliability with high confidence level. A concurrent fault detection and recovery scheme for MINs is considered by rerouting over redundant interconnection links under stringent real-time constraints for digital instrumentation as sensor networks. A switch architecture for concurrent testing and diagnosis is proposed. New performance models are developed and used to evaluate …

Statistical Approach To The Emi Modeling Of Large Asics By A Single Noise-Current Source, Giulio Antonini, James L. Drewniak, Marco Leone, Antonio Orlandi, Vittorio Ricchiuti

Electrical and Computer Engineering Faculty Research & Creative Works

Large and complex ASICs are source of propagating noise inside the powerbus planes. A lumped noise source model is proposed and validated by means of a statistics based method.

Dcim-Accelerated Smfma For Capacitance Extraction, L. (Lijun) J. Jiang, W. C. Chew, Y. C. Pan

Electrical and Computer Engineering Faculty Research & Creative Works

A new method to evaluate the SMFMA translators and near-field interactions for the capacitance extraction of the complicated structures in the multilayer medium is presented. As such, the spherical harmonic functions are extended into the complex plane to derive the closed forms of all multipole translators. This new technique can make the SMFMA setup stage one to two-orders faster compared to the old method. Moreover, it provides excellent accuracy with little computation costs.

Modified Fast Inhomogeneous Plane Wave Algorithm From Low Frequency To Microwave Frequency, L. (Lijun) J. Jiang, W. C. Chew

Electrical and Computer Engineering Faculty Research & Creative Works

A new method, MFIPWA, is proposed to extend the traditional MLFMA and FIPWA into the low frequency range. It uses the evanescent-wave extrapolation and translation techniques to overcome the low-frequency breakdown problem. The accuracy can be well controlled over a broad frequency range.

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.

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.

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.

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 …

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?".

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.

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.

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 …

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 …

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.

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.

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.

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.

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.

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 …

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 …