Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Other

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type

Articles 1681 - 1710 of 2904

Full-Text Articles in Engineering

Elevated Recharge Of Electrochemical Cells, Peter Novak Jan 2013

Elevated Recharge Of Electrochemical Cells, Peter Novak

Electrical Engineering Dissertations - Archive

Electrochemical cells are energy dense storage devices used to power everything from small portable electronics such as cell phones, to larger systems including electric and hybrid-electric vehicles or even electric utility backup supplies. In recent years, the electrochemical community has analyzed many aspects of cell performance with papers covering the influence of temperature, humidity, pressure, and various other factors on the aging of different types of cells. Despite the abundance of information on various issues, very little work has been presented in the area of high rate elevated charge and even less work regarding high rate pulsed elevated charge. This …

Go to article

Internal Structure And Dynamic Decisions For Coalitions On Graphs, Muhammad Aurangzeb Jan 2013

Internal Structure And Dynamic Decisions For Coalitions On Graphs, Muhammad Aurangzeb

Electrical Engineering Dissertations - Archive

The notions of collaboration, advantage, cost and impact are investigated in this dissertation, following are the details. Contribution to Cooperation between Agents for Routing in an Unknown Graph Using Reinforcement LearningFirst of all this work investigates the cooperation between agents to achieve a common goal. The problem of steering a swarm of autonomous agents out of an unknown maze to some goal located at an unknown location is discussed in this context. The routing algorithm given here provides a mechanism for storing data based on the experiences of previous agents visiting a node that results in routing decisions that improve …

Go to article

Wireless Power Transmission Based On Retro-Reflective Antenna Array, Shaoshu Sha Jan 2013

Wireless Power Transmission Based On Retro-Reflective Antenna Array, Shaoshu Sha

Electrical Engineering Dissertations - Archive

In recent years, there is a lot of research on wireless power transmission (WPT) for various applications, such as mobile devices, electric vehicles, implanted medical devices, sensors, RFID, etc. Compared to wired power transmission, WPT is more convenient and allows the devices to move more freely. Microwave beamforming WPT has been investigated extensively because its fast tracking capability, multiple target tracking capability and so on. A retro-reflective antenna array based on novel phase-conjugate method is proposed in this dissertation. The phase of the received signal is detected individually and simultaneously at each antenna and the conjugated phase is applied to …

Go to article

Rfid And Rtls Enhancement For Retained Surgical Instrument In The Body, Ida Lumintu Jan 2013

Rfid And Rtls Enhancement For Retained Surgical Instrument In The Body, Ida Lumintu

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Retained surgical items (e.g., sponges, needles, and instruments) are classified as preventable medical errors that cost the United States about $17 to $29 billion each year and the most frequently reported sentinel events in 2011 as reported by the Joint Commission. This research proposes a new approach to decrease such preventable medical errors by developing a Radio Frequency Identification-based Real Time Locating System (RTLS) for surgical operations (RfSurg). Patient safety concern, e.g. the excessive exposure of x-ray to the patient after the surgery, is a major motivation behind the need of RTLS in this research. The use of RTLS techniques …

Go to article

Multiport Dc Energy Conversion Systems, Hamid Behjati Jan 2013

Multiport Dc Energy Conversion Systems, Hamid Behjati

Electrical Engineering Dissertations - Archive

Sustainable energy sources and power electronic systems for utilizing such energy sources are becoming indispensible components of the modern power grid. The ability of multiport converters to mitigate the intermittency issues associated with these energy sources have made them attractive candidates for renewable energy conversion systems. Two single-stage multiport dc-dc converters, with independent and series outputs, are proposed in this dissertation. The advantages and applications of the proposed topologies are discussed. The ability of the proposed converters to regulate the input powers, coming from different energy sources, in addition to regulating the output voltages stands out. Specific switching schemes are …

Go to article

Investigation Of Degradation In Advanced Analog Mos Technologies, Md. Iqbal Mahmud Jan 2013

Investigation Of Degradation In Advanced Analog Mos Technologies, Md. Iqbal Mahmud

Electrical Engineering Dissertations - Archive

The focus of this work is to study the noise and degradation in advanced high and low voltage analog Metal Oxide Semiconductor Field Effect Transistors (MOSFET). Medium and high voltage transistors, especially lateral double diffused MOS (LDMOS) FETs have numerous practical applications. Although the LDMOS concept dates back some years, importance of low-frequency noise (also known as 1/f noise) characteristics of these devices have attracted attention only recently, due to some major reliability concerns. As an example, 1/f noise can cause a severe impact in System-on-Chip (SOC) applications when the LDMOS transistor is coupled with other devices or circuits through …

Go to article

Design And Fabrication Of Guided-Mode Resonant Tunable Optical Filters, Mohammad Jalal Uddin Jan 2013

Design And Fabrication Of Guided-Mode Resonant Tunable Optical Filters, Mohammad Jalal Uddin

Electrical Engineering Dissertations - Archive

Tunable optical filters have many applications in optical communication, multispectral and hyper-spectral imaging, bio-sensing, and display application. In optical communication, tunable optical filters (TOF) are used extensively in different wavelength division multiplexed (WDM) related applications. In display applications TOFs have been being used as color filters (CF) to separate primary colors from incident white light. In this study, two types of TOFs have been designed and fabricated: 1) thermo-optic tunable optical filters (TOTOF) working in optical communication bands and 2) tunable color filters (TCF) working in visible wavelength range.TOTOFs with deep (120 nm grating depth) and shallow (20 nm grating …

Go to article

Nanogap Break Junctions And Solid-State Micropores As Electronic Biosensors, Azhar Ilyas Jan 2013

Nanogap Break Junctions And Solid-State Micropores As Electronic Biosensors, Azhar Ilyas

Electrical Engineering Dissertations - Archive

Cancer has been the top ranked fatal disease for the last several decades. Most of the cancers remain silent at its earlier stage and are usually diagnosed at advanced and incurable phase. Early detection of cancer can have immediate and far reaching impact on better prognosis of cancer patients. Diseases are initially expressed at molecular and cellular scale and identification of these deadly diseases at such small scales would be a great step toward early detection. The study of biological molecules and diseased cells require efficient fabrication techniques to develop sensing devices with molecular size entrapment. Bio-nanotechnology and BioMEMs promise …

Go to article

Compressive Sensing For Wireless And Sensor Systems, Ji Wu Jan 2013

Compressive Sensing For Wireless And Sensor Systems, Ji Wu

Electrical Engineering Dissertations - Archive

Compressive sensing (CS) is an emerging field based on the revelation that a small collection of linear projections of a sparse signal contains enough information for stable, sub-Nyquist signal acquisition. It provides a potential way to acquire the sparse data efficiently, or equivalently, highly accurate recovery of sparse data from undersampled measurements. Huffman coding and compressive sensing are adopted to compress real-world wind tunnel data. Both uniform and non-uniform Huffman coding are evaluated in terms of the number of quantization levels, mean square error, codeword length and compression ratio. The main drawback of Huffman coding is that it requires calculating …

Go to article

Cooperative Control Of Multi-Agent Systems; Stability, Optimality And Robustness, Kristian Hengster Movric Jan 2013

Cooperative Control Of Multi-Agent Systems; Stability, Optimality And Robustness, Kristian Hengster Movric

Electrical Engineering Dissertations - Archive

In this work design methods are given for distributed synchronization control of multi-agent systems on directed communication graphs. Conditions are derived based on the relation of the graph eigenvalues to a region in a complex plane that depends on the single-agent system and the solution of the local Riccati equation. The synchronizing region concept is used. Cooperative observer design, guaranteeing convergence of the local estimates to their true values, is also proposed. The notion of convergence region for distributed observers is introduced. A duality principle is shown to hold for distributed observers and controllers on balanced graph topologies. Application of …

Go to article

Sparsity Enhanced Reconstruction Algorithms For Diffuse Optical Tomography, Jixing Yao Jan 2013

Sparsity Enhanced Reconstruction Algorithms For Diffuse Optical Tomography, Jixing Yao

Electrical Engineering Dissertations - Archive

Conventional reconstruction algorithms for diffuse optical tomography (DOT) is based on Tikhonov regularization method and the simple white Gaussian noise (WGN) assumption. These approaches usually lead to the following problems: 1. The reconstructed images are blurry; 2. In 3D reconstruction problems, the reconstructed objects are usually in the wrong depths; 3. The shape of a reconstructed object might be different from its original one due to the noise.In this work, after study the nature of DOT images as well as the data acquisition process, several sparsity regularization related reconstruction methods were developed to improve the spatial resolution as well as …

Go to article

Reliability Unit Commitment In Ercot Nodal Market, Hailong Hui Jan 2013

Reliability Unit Commitment In Ercot Nodal Market, Hailong Hui

Electrical Engineering Dissertations - Archive

The Electric Reliability Council of Texas (ERCOT) is the independent system operator (ISO) that ensures a reliable electric grid and efficient electricity markets in the ERCOT region. ERCOT has successfully transited from a zonal market to an advanced nodal market since Dec. 2010. In the new ERCOT nodal wholesale market, a reliability unit commitment (RUC) process has been designed and implemented to ensure transmission system reliability and security. The main objective of RUC is to ensure that enough resource capacity, in addition to ancillary service capacity, is committed in the right locations to reliably serve the forecasted load in the …

Go to article

Nanostructured Surfaces Using Thermal Nanoimprint Lithography: Applications In Thin Membrane Technology, Piezoelectric Energy Harvesting And Tactile Pressure Sensing, Bhargav Pradip Nabar Jan 2013

Nanostructured Surfaces Using Thermal Nanoimprint Lithography: Applications In Thin Membrane Technology, Piezoelectric Energy Harvesting And Tactile Pressure Sensing, Bhargav Pradip Nabar

Electrical Engineering Dissertations - Archive

Nanoimprint lighography (NIL) is emerging as a viable contender for fabrication of large-scale arrays of 5-500 nm features. The work presented in this dissertation aims to leverage the advantages of NIL for realization of novel Nano Electro Mechanical Systems (NEMS). The first application is a nanoporous membrane blood oxygenator system. A fabrication process for realization of thin nanoporous membranes using thermal nanoimprint lithography is presented. Suspended silicon nitried membranes were fabricated by Lowe-Pressure Chemical Vapor Deposition (LPCVD) in conjunction with a potassium hydroxide-based bulk michromachining process. Nanoscale features were imprinted into a commercially available thermoplastic polymer resist using a prefabricated …

Go to article

A Low-Noise, Low-Power Cmos Amperometric Circuit For Glucose Sensing, Niranjan Karandikar Jan 2013

A Low-Noise, Low-Power Cmos Amperometric Circuit For Glucose Sensing, Niranjan Karandikar

Electrical Engineering Dissertations - Archive

Diabetes is disorder associated with an insufficiency of insulin secretion. Large number of people around the world suffers from this disorder which can result into damages to eyes, kidneys, nerves and even death. One of the most common methods to detect the diabetes is to monitor the levels of glucose is the blood stream. Other biological fluids like tear fluid can also be used to detect levels of glucose. With emergence of MEMS technology several biosensors are developed, less invasive or non-invasive, which can detect these glucose levels from blood or tear. Central idea behind the developments of these biosensors …

Go to article

Implementation Of An Adaptive Block Filter On Sub-Blocks Of A Macroblock In H.264/Avc, Bhavana Prabhakar Jan 2013

Implementation Of An Adaptive Block Filter On Sub-Blocks Of A Macroblock In H.264/Avc, Bhavana Prabhakar

Electrical Engineering Theses - Archive

Plenty of coding tools are being developed to boost the efficiency of H.264/AVC. Some of these tools are implemented in the key technical area (KTA). The adaptive interpolation filter (AIF) [3], the high precision interpolation filter [5], and the adaptive loop filter (ALF) [4] have already been introduced in order to provide a more precise reference picture. Other efficient coding methods, such as the motion vector competition [6] and the extended macro-block (MB) [7], are also implemented in the KTA [16].In order to improve the coding efficiency of H.264/AVC, an adaptive prediction block filter (APBF) based on Wiener filter is …

Go to article

Embedded And Rf Powered Implantable Medical Device For Gastric Electrical Stimulation (Ges), Guru Moorthy Ravi Jan 2013

Embedded And Rf Powered Implantable Medical Device For Gastric Electrical Stimulation (Ges), Guru Moorthy Ravi

Electrical Engineering Theses - Archive

Gastric electrical stimulation (GES) has attracted significant attention in the treatment for Gastroparesis-a common disorder caused in patients suffering from diabetes, cancer and Parkinson's disease. Symptoms include vomiting, nausea, abdominal bloating etc. due to loss of motility in the stomach muscles. GES uses electrical pulses on the stomach tissues to help regain normal motility and reduce the symptoms. Conventional gastric stimulator needs a long surgery to be implanted and it is a big pacemaker like device that runs by a non-rechargeable battery. It has to be replaced once the battery gets exhausted every 5 to 6 years. Hence another round …

Go to article

Diagnosing Wi-Fi Association Issues And Optimizing Network Performance, Suma Subbarao Jan 2013

Diagnosing Wi-Fi Association Issues And Optimizing Network Performance, Suma Subbarao

Electrical Engineering Theses - Archive

Extensive deployment of Wi-Fi networks at homes and public places has triggered research interest in several aspects of Wi-Fi technology like deployment strategies and optimization. People use Wi-Fi or 802.11 networking, to connect their computers at home or office for instant internet access and it is a common scenario to have faced association and network congestion problems. Finding appropriate solution to these issues is a challenging task. In this thesis, an attempt has been made to solve Wi-Fi related concerns through a novel approach. Diagnosing problems occurring during the association process with the network and getting better throughput from the …

Go to article

A Cmos Switched Capacitor Based Amperometric Readout Circuit For Microneedle Glucose Sensor, Sunil Govardhan Jan 2013

A Cmos Switched Capacitor Based Amperometric Readout Circuit For Microneedle Glucose Sensor, Sunil Govardhan

Electrical Engineering Theses - Archive

Accurate regulation of glucose metabolism is one of the key factors in keeping a healthy state among mammalians. Increase in failure of this natural blood glucose regulatory mechanism has propelled the research for improvements in blood glucose measurement and its regulation. Also, advancement in the research of internet of things has increased the demand for smart sensors creating a revolution in health care industry and which has inturn led to the improvement in point-of-care testing.Therefore in this thesis work a microneedle glucose sensor is chosen as it can be fabricated by MEMS process which allows it to be easily integrated …

Go to article

Swcc And Clay Mineralogy Based Models For Realistic Simulation Of Swell Behavior Of Expansive Soils, Aravind Pedarla Jan 2013

Swcc And Clay Mineralogy Based Models For Realistic Simulation Of Swell Behavior Of Expansive Soils, Aravind Pedarla

Civil Engineering Dissertations - Archive

Predicting the volume change behavior of expansive soils has been a major challenge to the engineers in the past few years, due to the intricate couple effects caused by different soil composition parameters toward swelling. Hence, the behavior of an expansive soil is better understood with its inherent composition parameters. For this research, eight natural expansive clays have been sampled from different active swell zones across The United States. Basic soil classification was performed on these soil to identify the high plasticity and low plasticity clays. The swell behavior of these clays are studied using different testing methods and initial …

Go to article

Non-Linear Finite Element-Based Material Constitutive Law For Zero Slump Steel Fiber Reinforced Concrete Pipe Structures, Alena Mikhaylova Jan 2013

Non-Linear Finite Element-Based Material Constitutive Law For Zero Slump Steel Fiber Reinforced Concrete Pipe Structures, Alena Mikhaylova

Civil Engineering Dissertations - Archive

This study presents a comprehensive investigation of performance and behavior of steel-fiber reinforced concrete pipes (SFRCP). The main goal of this study is to develop the material constitutive model for steel fiber reinforced concrete used in dry-cast application. To accomplish this goal a range of pipe sizes varying from 15 in. (400 mm) to 48 in. (1200 mm) in diameter and fiber content of 0.17%, 0.25%, 0.33%, 0.5%, 0.67% and 83% by volume were produced. The pipes were tested in three-edge bearing condition to obtain the load-deformation response and overall performance of the pipe. The pipes were also subjected to …

Go to article

Evaluation Of Quality And Sustainability Incentives To Optimize The Indonesian To The United States Crude Oil Supply Chain, Restu Purwaningtyas Sunarto-Bussey Jan 2013

Evaluation Of Quality And Sustainability Incentives To Optimize The Indonesian To The United States Crude Oil Supply Chain, Restu Purwaningtyas Sunarto-Bussey

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The New York Times explained that the United States increased its dependence on oil from Saudi Arabia by more than 20 percent last year (Krauss 2012). The United States of Energy Information Administration (U.S. EIA) stated that oil from Saudi Arabia was accounted for 14 percent of the U.S. crude oil and petroleum products in 2012 ("Oil: Explained" 2012). This is problematic due to the fact that 14 percent of the U.S. net crude oil and petroleum products imports come from one country, Saudi Arabia. What happens to the U.S. economy when Saudi Arabia manipulates demand and possibly stops exporting …

Go to article

Gaseous Corrosion In Hard Disk Drive: A Computational Study, Hardik Shah Jan 2013

Gaseous Corrosion In Hard Disk Drive: A Computational Study, Hardik Shah

Mechanical and Aerospace Engineering Theses - Archive

HDD is the largest digitally encoded data storage device. HDD is used to store digital data in data centers, computers and laptops. A typical HDD consists of a casing, an actuator arm, actuator axis, head, platters, power connectors, and jumper pins. The platter is made up of non-magnetic material and is covered by magnetic material, which stores the data. The magnetic heads are mounted on a moving actuator arm to read and write the data. One of the modes of failure of a HDD is corrosion. The parts of the HDD are corroded by coming in contact with the contaminants. …

Go to article

Chemoelastoplastic Analysis Of A Copper-Graded Silicon Nanorod For Lithium-Ion Battery Anode Application, Chao Ji Jan 2013

Chemoelastoplastic Analysis Of A Copper-Graded Silicon Nanorod For Lithium-Ion Battery Anode Application, Chao Ji

Mechanical and Aerospace Engineering Theses - Archive

Lithium-ion batteries are currently widely used in electronics, electrical vehicles and other devices/machines. Along with the mounting demand for much improved performance in these developing technological fields, silicon was recognized to possess much higher energy capacity when used as an anode than graphite that is currently used. However, there occurs colossal volume expansion of silicon anode during the lithiation process. The material consequently suffers enormous stresses, especially, at the interface with a current collector, which deteriorate the device quickly during cycling. To prevent the active material (Si) from falling off from a current collector, nanoengineering strategies have been suggested, including …

Go to article

Application Of Phase Change Material In Sustainable Cooling Of Data Centers, Nikhil Dhiman Jan 2013

Application Of Phase Change Material In Sustainable Cooling Of Data Centers, Nikhil Dhiman

Mechanical and Aerospace Engineering Theses - Archive

The ever increasing information technology heat load and data center cooling energy are the main reasons to investigate the performance of microencapsulated phase change slurry over other heat transfer fluids. In recent years, more effort is being made on the development of a new technique to use the phase change materials as pump-able heat transfer fluid and as heat storage system.Microencapsulated phase change slurry is dispersion where the phase change material, microencapsulated by a polymeric capsule, is dispersed in water. Compared to water, these new fluids have a higher heat capacity during phase change and a possible enhancement, as a …

Go to article

Thermal Management Method For Foil Bearings In Turbine Hot Section, Tejas Devidas Patil Jan 2013

Thermal Management Method For Foil Bearings In Turbine Hot Section, Tejas Devidas Patil

Mechanical and Aerospace Engineering Theses - Archive

Recently, Air Foil Bearings (AFB) are gaining higher industrial acceptance in micro-turbo machinery. AFB show high speed operating capability and environmental friendly operation in comparison to rolling element bearings. Utilization of ambient air as a lubricant eliminates maintenance of a pressurized oil lubricating system. AFBs are therefore a feasible alternative to oil lubricated bearings in small machines. High speed operation results in thermal management issues which can be solved through a suitable cooling mechanism. Axial cooling by passing air through bearing support structure (called bump foils) is the most commonly used. In this method, cooling is achieved in the heat …

Go to article

Immersion Cooling Of High End Data Center Server And Validation Through Experiments, Harsh Patel Jan 2013

Immersion Cooling Of High End Data Center Server And Validation Through Experiments, Harsh Patel

Mechanical and Aerospace Engineering Theses - Archive

Despite recent improvements in data center cooling efficiency such as hot and cold aisle and air side economizer, air cooling may not have the capacity to cool high end racks such as from IBM's NetBAY42 (150Kw and above). Increasing computer capabilities in data center has resulted in increase in rack power density per square ft as indicated by the latest uptime. The cooling of such high powered servers and corresponding racks poses a significant challenge to thermal engineers.The use of immersion cooling is novel approach for data center cooling. In this study after some modification high powered server is fully …

Go to article

Real Time Motion Control For Natural Human Robot Interaction, Suresh Sampathkumar Jan 2013

Real Time Motion Control For Natural Human Robot Interaction, Suresh Sampathkumar

Electrical Engineering Theses - Archive

In this thesis, we present the research work performed with various robots including Android PKD, Zeno and the Atlas robot. The main focus of this thesis is to develop algorithms for vision based natural human robot interaction in real time. Zeno is a childlike robot that we use for the research related to Autism in children. Children with Autism who lack motor skills tend to shy away from humans. In this project we use the robot Zeno that is capable of facial expressions, arm and body motions to teach motor skills to them. For this purpose we developed a program …

Go to article

Transfer-Printed Photonic Crystal Nanomembrane Fano Resonance Filters And Modulators, Yi-Chen Shuai Jan 2013

Transfer-Printed Photonic Crystal Nanomembrane Fano Resonance Filters And Modulators, Yi-Chen Shuai

Electrical Engineering Dissertations - Archive

This dissertation presents the research work on photonic crystal nanomembrane Fano resonance devices based on transfer printing techniques. Ultra-compact high quality (Q) factor optical filters have been design, fabricated, and characterized based on single-layer and coupled double-layer photonic crystal slabs (PCS). Optical filters have also been designed and investigated for potentially high speed spatial lighting modulations. Fano resonance membrane reflectors with operation wavelength bands cover from near-infrared to mid and far-infrared have also been fabricated based on both reaction ion-etching and magnetic field guided metal-assisted chemical etching processes.Based on crystalline semiconductor nanomembrane transfer printing technique, we designed and experimentally demonstrated …

Go to article

Cmos Analog Correlator Based Glucose Sensor Readout Circuit, Varun K. Shenoy Jan 2013

Cmos Analog Correlator Based Glucose Sensor Readout Circuit, Varun K. Shenoy

Electrical Engineering Dissertations - Archive

Recent investigations show research and development of alternative methods of glucose sensing using electrochemical biosensors to help significantly reduce the difficulties associated with treating diabetes. The integration of microelectronic circuit technology with biosensors is generating greater research interest. The advantages of small size and less power consumption of integrated circuits (ICs) are helping with the realization of biosensors for improved performance. The major challenges involving designing of readout ICs for the electrochemical biosensors are accuracy and range. In this research work, an analog correlator based readout circuit for amperometric glucose electrochemical biosensors is designed and implemented. It is designed to …

Go to article

A Numerical Study Of Incompressible Fluid Flow Over A Forward Facing Step At Various Grades, Peter Andrew Martinez Jan 2013

A Numerical Study Of Incompressible Fluid Flow Over A Forward Facing Step At Various Grades, Peter Andrew Martinez

Mechanical and Aerospace Engineering Theses - Archive

The study of the effect of natural forces on hydraulic structures is of great concern for the accurate prediction of when a design could be at risk of failure. In recent times the use of the shallow water equations to predict the behavior of the free surface for flow over a step has proven inaccurate because only a hydrostatic pressure distribution is considered. One of the phenomena that will not be accounted for with the shallow water equations in such a setup is the formulation of undular bore type waves on the surface. In order for a more accurate representation …

Go to article

First Prev Next Last