Electrical and Computer Engineering Commons^™

An Invariance Transformation Algorithm For Defect Characterization Of Ultrasonic Signals For The Nondestructive Evaluation Of Concrete, Michael Dominic Ciocco

Theses and Dissertations

Nondestructive evaluation (NDE) techniques offer cost-effective strategies for monitoring the integrity of a variety of civil infrastructure, such as natural gas and sewer pipelines, without the need to take the system off-line. However, interpretation of NDE signals in terms of the location, size, and shape of underlying flaws in the material being inspected is fraught with difficulty. Typically, variations in the testing signal due to operational parameters have created a significant challenge for defect characterization. This thesis proposes, develops, and validates a defect characterization algorithm that compensates for operational variables and maps the test signal to a visual defect profile. …

Automated Segmentation Of Radiodense Tissue In Digitized Mammograms Using A Constrained Neyman-Pearson Classifier, Jeremy Thomas Neyhart

Theses and Dissertations

Breast cancer is the second leading cause of cancer related mortality among American women. Mammography screening has emerged as a reliable non-invasive technique for early detection of breast cancer. The radiographic appearance of the female breast consists of radiolucent (dark) regions and radiodense (light) regions due to connective and epithelial tissue. It has been established that the percentage of radiodense tissue in a patient's breast can be used as a marker for predicting breast cancer risk. This thesis presents the design, development and validation of a novel automated algorithm for estimating the percentage of radiodense tissue in a digitized mammogram. …

Milliwatt Power Deep Ultraviolet Light-Emitting Diodes Over Sapphire With Emission At 278 Nm, J. P. Zhang, A. Chitnis, V. Adivarahan, S. Wu, V. Mandavilli, R. Pachipulusu, M. Shatalov, Grigory Simin, J. W. Yang, M. Asif Khan

Faculty Publications

We report on AlGaN multiple-quantum-well (MQW)-based deep ultraviolet light-emitting diodes over sapphire with peak emission at 278 nm. A new buffer layer growth process was used to reduce the number of defects and hence the nonradiative recombination. The improved material quality and carrier confinement resulted in pulsed powers as high as 3 mW at 278 nm and a significantly reduced deep-level-assisted long-wavelength emission.

Chaotic Free-Space Laser Communication Over Turbulent Channel, N. F. Rulkov, Mikhail Vorontsov, L. Illing

Electro-Optics and Photonics Faculty Publications

The dynamics of errors caused by atmospheric turbulence in a self-synchronizing chaos-based communication system that stably transmits information over a ∼5  km free-space laser link is studied experimentally. Binary information is transmitted using a chaotic sequence of short-term pulses as a carrier. The information signal slightly shifts the chaotic time position of each pulse depending on the information bit. We report the results of an experimental analysis of the atmospheric turbulence in the channel and the impact of turbulence on the bit-error-rate performance of this chaos-based communication system.

A Reversible Three-Phase Step Up/Down Switching Mode Rectifier, Jenn-Jong Shieh

Journal of Marine Science and Technology

In this paper, focus on the null space vector duty cycle control, a reversible three-phase step up/down switching mode rectifier is proposed attain clean sinusoidal input current, unity power factor, bidirectional power flow, step up/down output DC voltage and insensitivity for a voltage input. In addition, a precise simulation model is proposed to simulation by using PC software tools. Finally, some simulation and experimental results are presented for verification.

Buffer Interference Architecture, Vladimir I. Prodanov

Electrical Engineering

An up to 3× breakdown voltage tristate capable integrated circuit CMOS buffer includes a level shifter circuit and a driver circuit. The driver stage includes a series connected n-channel and p-channel cascode stacks, each including at least three transistors. Dynamic gate biasing is provided for the third n-channel and p-channel cascode transistors to prevent voltage overstress of the cascode transistors. The level shifter circuit includes at least one pseudo N-MOS inverter including an input transistor, a protective cascode stack including at least one n-channel cascode transistor, and a load transistor. The level shifter provides at least one voltage shifted input …

An Assessment Of Seawinds On Quikscat Wind Retrieval, David Draper, David G. Long

Faculty Publications

The scatterometer ocean wind retrieval process produces several possible solutions or ambiguities at each point, requiring a separate ambiguity selection step to infer a unique wind vector field. An ambiguity selection error occurs when the selected wind vector is not the closest ambiguity to the true wind. The current ambiguity selection routine for SeaWinds is ad hoc, but performs well under most circumstances. Factors such as instrument noise and rain can also cause the estimated wind flow to deviate from the true wind. A quality assurance (QA) analysis is performed to assess the ambiguity selection effectiveness and noise level of …

Optimation Model Of Planning Investment Dockyard With Approach Multi Objective Goal Programming, Ali Azhar

Makara Journal of Technology

Optimation model of planning investment dockyard with approach multi objective goal programming. The purpose of this research is to determine decision variable, goal function, alternative priority and achievement function in investment planning. From this optimation component, the model of ship yard investment planning could be achieved. The model of developed model in this research was the optimation of ship yard investment planning using multi objective goal programming approach. The model consist of 5 decision variable, 11 goal function, 2 alternative priority and 11 achievement functions. The model implementation was done toward PT ASSI investment planning. The calculation using from Quantitative …

The Use Of 2d Plastic Grating For Surface Profile And Dimension Manufacture Product Measurements By Using Ndt Moiré Technique, Retno Wigajatri P., Dini Andiani

Makara Journal of Technology

The Use of 2D Plastic Grating for Surface Profile and Dimension Manufacture Product Measurements by Using NDT Moiré Technique. Research of measuring the shape and dimension of object using the moiré technique have been done. Measurement have been made by observing the moiré space as a result of interaction between grating and its shadow casted on the object’s surface caused by the projector lamp with CCD camera. The acquired data was further processed by way of off-line. By successive phase shifts that is π/2, π dan 3π/2 towards the table tennis ball at the distance of 48 cm from the …

Emission Gas Reducer On Motor Vehicle, Automobile, Light Engine Of Boat And Stationary Combustion Engine., I Gusti Bagus Wijaya Kusuma

Makara Journal of Technology

Emission gas reducer on motor vehicle, automobile, light engine of boat and stationary combustion engine. The use of motor vehicle should be followed by protection against damages on the environment, since the exhaust gas from combustion engine has significantly affect on air and environmental pollution. One method to solve the problems in air pollution has been done by using a re-heater designed in Mechanical Engineering Department, University of Udayana. In accordance to the test on the re-heater, it can be seen very clear that the re-heater has significantly reduce the CO emission of about 54%. It also reduces the CO2 …

Application Of Remote Sensing For Mapping Soil Organic Matter Content, Bangun Muljo Sukojo, Wahono Wahono

Makara Journal of Technology

Application of Remote Sensing for Mapping Soil Organic Matter Content. Information organic content is important in monitoring and managing the environment as well as doing agricultural production activities. This research tried to map soil organic content in Malang using remote sensing technology. The research uses 6 bands of data captured by Landsat TM (Thematic Mapper) satellite (band 1, 2, 3, 4, 5, 7). The research focuses on pixels having Normalized Difference Soil Index (NDSI) more than 0.3. Ground-truth data were collected by analysing organic content of soil samples using Black-Walkey method. The result of analysis shows that digital number of …

Iodat Analysis Content In Cooking Ingredients Using Iodometry And X-Ray Fluorescence Methods., Nelson Saksono

Makara Journal of Technology

Iodat Analysis Content in Cooking Ingredients Using Iodometry and X-ray Fluorescence Methods. Salt iodization program using iodine fortification into salt method is the best method that is effective and economical to overcome the problems caused by iodine deficiency. However in, its development there are some issues clamed that the use of iodized salt is ineffective since iodine content reduces, even disappear when the salt mix with other cooking ingredients. In order to investigated the existence of iodine in cooking ingredients, a research applying iodometry and X-ray fluorescence methods was carry out. The result obtained by iodometry method showed decreases in …

Self-Ignition Properties Of Peat, Palm Shell Fibre And Woods, Yulianto Sulistyo Nugroho

Makara Journal of Technology

Self-ignition properties of peat, palm shell fibre and woods. Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures …

An Optimum Greedy Algorithm For Choosing Minimal Set Of Conflicting Constraints In The Point Sequencing Problem, Florent Launay, Mitra Debasis

Electrical Engineering and Computer Science Faculty Publications

In this work, we first have proposed a technique to define the "causes" of inconsistency on an online point based reasoning constraint network. Second, we introduce an algorithm that proposes the user a minimal set of relations to remove when inconsistencies are detected. We have developed and implemented a battery of algorithms for the purpose of this type of reasoning. Some useful theorems and properties are defined for proving the 'minimal' aspect of the algorithm. Finally, we found that our investigation was a polynomially solvable sub problem of the vertex cover problem.

Surface Modeling And Analysis Using Range Images: Smoothing, Registration, Integration, And Segmentation, Yiyong Sun

Doctoral Dissertations

This dissertation presents a framework for 3D reconstruction and scene analysis, using a set of range images. The motivation for developing this framework came from the needs to reconstruct the surfaces of small mechanical parts in reverse engineering tasks, build a virtual environment of indoor and outdoor scenes, and understand 3D images.

The input of the framework is a set of range images of an object or a scene captured by range scanners. The output is a triangulated surface that can be segmented into meaningful parts. A textured surface can be reconstructed if color images are provided. The framework consists …

Self-Consistent Three Dimensional Models For Quantum Ballistic Transport In Open Systems, Eric Polizzi, N. Ben Abdallah

Eric Polizzi

A quasi-three-dimensional model for quantum ballistic transport in nanostructures is proposed. The model goes beyond the Thomas-Fermi approximation and is numerically more tractable than the full three-dimensional Schrödinger-Poisson model. Its derivation relies on the strong confinement of electrons at the heterojunction which allows us to split the three-dimensional Schrödinger equation into a one-dimensional Schrödinger equation for the confined direction and a two-dimensional Schrödinger equation in the transport direction. The space charge effects are taken into account in a three-dimensional framework. Numerical simulations of quantum waveguide devices such as T stubs and directional couplers are used to illustrate the accuracy of …

Dynamic Yield Analysis And Enhancement Of Fpga Reconfigurable Memory Systems, Minsu Choi, Nohpill Park

Electrical and Computer Engineering Faculty Research & Creative Works

This paper addresses the issues of field programmable gate arrays (FPGA) reconfigurable memory systems with faulty physical memory cells and proposes yield measurement techniques. Static yield (i.e., the yield which does not take into account the inherited redundancy utilization for repair) and dynamic yield (i.e., the yield which takes into account the inherited redundancy utilization for repair) of FPGA reconfigurable memory systems and their characteristics are extensively analyzed. Yield enhancement of conventional memory systems relies on additional redundancy, but FPGA reconfigurable memory systems have inherited redundancy and customizability. Thus, they can accommodate numerous target memory configurations, and redundant memory cells, …

Analysis And Characterization Of Single-Poly Floating Gate Devices In 0.35um Pdsoi Process, Chandra Sekhar Acharyulu Durisety

Masters Theses

The purpose of this thesis is to demonstrate a single-poly Floating Gate Device (FGD) in 0.35 m Partially Depleted Silicon On Insulator (PDSOI) process for use in analog circuits for post process trimming. Floating gate devices with different aspect ratios have been fabricated to facilitate this behavioral study in PDSOI process. Fundamentals of floating gate devices, the advantages and disadvantages of PDSOI compared to bulk CMOS with respect to single-poly floating gate devices are discussed. Various experiments on behavior and performance of threshold voltage have been conducted and its variation with programming/erasing time and amplitude has been analyzed. The single-poly …

Verification Of Intellectual Property Blocks Using Reconfigurable Hardware, Koay Teng Kuan

Masters Theses

The purpose of this thesis is to develop a procedure to verify intellectual property (IP)cores on the Pilchard platform which contains reconfigurable hardware. The hardware and tools used for the verification process are documented.

Two IP cores are used as examples of how the Pilchard design flow is to be applied. One core that does a simple logical function is implemented to serve as a demonstration of Pilchard read and write operations. To demonstrate the versatility of the hardware platform, a complex core that performs a Fast Fourier Transform operation was also implemented successfully.

Results from these IP implementations indicate …

State Of Charge Estimation For Batteries, Baskar Vairamohan

Masters Theses

In this thesis, a methodology to accurately estimate the state of charge (SOC ) of the batteries used in Hybrid Electric Vehicles (HEV) is proposed. A linear relationship exists between open circuit voltage (V_OC ) and SOC . In the proposed scheme, a system theory approach is employed to identify the open circuit voltage of the battery, from which the state of charge of the battery is determined. This method is very unique because it estimates the V_OC of the battery in the vehicle even under load conditions. A state variable approach yields a set of …

Implementation Of Gy-Eq For Deterministic Effects Limitation In Shield Design, John W. Wilson, Myung-Hee Y. Kim, Giovanni De Angelis, Francis A. Cucinotta, Nobuaki Yoshizawa, Francis F. Badavi

Mathematics & Statistics Faculty Publications

The NCRP has recently defined RBE values and a new quantity (Gy-Eq) for use in estimation of deterministic effects in space shielding and operations. The NCRP's RBE for neutrons is left ambiguous and not fully defined. In the present report we will suggest a complete definition of neutron RBE consistent with the NCRP recommendations and evaluate attenuation properties of deterministic effects (Gy-Eq) in comparison with other dosimetric quantities.

Training Fuzzy Systems With The Extended Kalman Filter, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

The generation of membership functions for fuzzy systems is a challenging problem. We show that for Mamdani-type fuzzy systems with correlation-product inference, centroid defuzzification, and triangular membership functions, optimizing the membership functions can be viewed as an identification problem for a nonlinear dynamic system. This identification problem can be solved with an extended Kalman filter. We describe the algorithm and compare it with gradient descent and with adaptive neuro-fuzzy inference system (ANFIS) based optimization of fuzzy membership functions. The methods discussed in this paper are illustrated on a fuzzy filter for motor winding current estimation, and are compared with Butterworth …

Online Determination Of The Steady-State Condition Of An Aerodynamic Test Article Mounted In A Wind Tunnel Test Cell, Martin Vincent Fette

Masters Theses

The Propulsion Wind Tunnel (PWT) facility at Arnold Engineering Development Center is devoted to aerodynamic and propulsion integration testing of large-scale aerodynamic models. Models of aircraft, missiles and rockets are tested at simulated altitude conditions from sea level to about 150,000 feet.

Before the data acquisition sequence, it is necessary to establish that the model position has stabilized following the movement of the test model to a new orientation. The existing procedure requires an extra delay, after moving the model, before data is acquired. This delay, however, may be more or less than necessary, resulting in wasted testing time or …

Supervisory Control And Data Acquisition (Scada) Systems, George H. Baker, Allan Berg

George H Baker

Our critical national infrastructure systems have become almost universally dependent upon computer-based control systems technically referred to as supervisory control and data acquisition (SCADA) systems. SCADA systems evolved from the telemetry and event-alarm systems developed in the early days of utilities. With the widespread use of SCADA systems, computers have become the "basis element" for much of our critical infrastructure. Thus, the disruption of controlling computer terminals and networks due to natural disasters, electric power failure, accidents or malicious activity can have catastrophic consequences.

Preparation And Electrochemical Lithium Intercalation Performance Of Different Shaped Carbon Nanotube, Mao-Hui Chen, Zhen-Cai Huang, Guo-Tao Wu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

In the present work, different shaped carbon nanotubes were produced by the general CVD and the template method at different temperature (600 ℃,700 ℃) with the reaction gas of acetylene. The morphology, structure and the electrochemical lithium intercalation performance were comparatively studied and characterized by TEM, HRTEM, SEM, XRD, Raman techniques and Charge/Discharge Test. It was found that the different preparation methods and temperatures all had an obvious effect on these properties of carbon nanotubes. In our samples, with the increase of preparation temperature, the degree of crystallinity decreased, and the reversible specific capacity increased respectively.

Mechanistic Study Of Oxidation Of Hypophosphite On Pt Electrodes By Sniftirs, Tai-Xiang Jiang, Hui-Huang Wu

Journal of Electrochemistry

The oxidation of hypophosphite on a polycrystalline platinum electrode was studied by SNIFTIRS and cyclic voltammetry, the in-situ IR spectra were analyzed as a function of Pt electrode potentials in the solution of 0.5 mol/L H 2SO 4+0.1 mol/L NaH 2PO 2. It was found that the dissociative adsorption of hypophosphite ions occurs on Pt surface, and the oxidation product is H 3PO 4, rather than H 2PO 3 - which was considered to produce on Ni electrodes, thereby a new insight into mechanism of hypophosphite oxidation on Pt in acidic media was provided.

Nano-Sized Cobalt-Based Oxides As Negative Electrode For Lithium-Ion Batteries, Feng Huang, Zheng-Yong Yuan, Yun-Hong Zhou, Ju-Tang Sun

Journal of Electrochemistry

Nanosized cobalt-based oxide (Co 3O 4, CoB 1.36 O 2.8 and CoB 0.5 Al 0.1 O 1.5 ) samples were prepared by rheological phase method and were tested as anodes in secondary lithium batteries. The cells were cycled between 0.01V and 3.00 V. The best electrochemical performance was obtained from the Li/Co 3O 4 cell, which retained 95% of its initial capacity (931 mAh/g) after 30 cycles. The doping of B, Al reduced the reversible capacity during the first discharge/charge cycle, and the quantity of reversible capacity reduced with B, A1 increasing. The modifying structures at difference charge and discharge …

Electrocatalytic Oxidation Of Formic Acid On Molybdate-Modified Platinum Electrode, Jun-Hua Du, Xue-Hui Xu, Hong Li, Hong-Yu Cheng, Wei-Shan Li

Journal of Electrochemistry

The electrochemical behavior of molybdates on a platinum electrode in H 2SO 4 solutions with different H 2SO 4 concentrations was studied by cyclic voltammetry and double chronoamperometry. Molybdates were reduced to adsorb hydrogen molybdenum bronzes on the platinum electrode in H 2SO 4 solutions during cathodically potential sweep. The hydrogen molybdenum bronzes were oxidized to different forms of hydrogen molybdenum bronzes with less hydrogen, depending on the H 2SO 4 concentration. Platinum electrode was modified by these hydrogen molybdenum bronzes. However, this modified electrode was not stable in H 2SO 4 solutions. The modified electrode was used to study …

Preparation And Performance Of Lifeo_2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu

Journal of Electrochemistry

A novel cathode for molten carbonate fuel cells was prepared by coating LiFeO 2 over the surface of porous NiO cathode by a simple combustion process. The analytical results of X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the LiFeO 2 coating on the surface of NiO particles consisted of nonometer-sized LiFeO 2 grains and sintered tightly with the NiO particles. The LiFeO 2 coating dramatically reduced the contacting area of NiO with the carbonate melts, thus the solubility of NiO in the carbonate melts was decreased. Meanwhile, …

Steady State Simulation Of Ysz Intermediate-Temperature Fuel Cell, Zi-Jing Lin, Ye Gu, Xiao-Hua Zhang

Journal of Electrochemistry

With a coupled 2D electrochemical and thermal modeling software, the characteristics of the steady state operation of the intermediate-temperature fuel cell with thin yttria-stabilized zirconia(YSZ) electrolyte was analyzed. The parameters of I-V equation were obtained from fitting the experiment results and the choice of grid points was determined by balancing the accuracy requirement and computational efficiency. The temperature fields at different operation circumstances such as flow designs, material choices for interconnect, were examined. The dependences of the output power and cell efficiency on the operating voltage at different temperatures were studied. Based upon the analysis of the temperature profile, it …