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Articles 2641 - 2670 of 3180

Full-Text Articles in Engineering

Reliability Of Advanced Dielectrics In Gate Oxide And Device Level Packaging In Mems, Mohammad Shahriar Rahman Jan 2009

Reliability Of Advanced Dielectrics In Gate Oxide And Device Level Packaging In Mems, Mohammad Shahriar Rahman

Electrical Engineering Dissertations - Archive

The focus of this work is to study the feasibility, reliability and applicability of advanced dielectrics in both Metal Oxide Semiconductor Field Effect Transistor (MOSFET) gate oxide and device level packaging for Microelectromechanical Systems (MEMS). The scaling of silicon based MOSFET is approaching physical limits imposed by atomic structure. This continuous scaling trend of complementary MOSFET technologies introduces new challenges relating to power, heat and device behavior. To overcome the power dissipation and heating problems arising from gate leakage, high dielectric constant (high-k) materials are proposed. Hafnium based high-k dielectric layers and metal gate electrodes have been extensively investigated as …

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Optimization Of Hydrogen Filling Station, Weiping Xiao Jan 2009

Optimization Of Hydrogen Filling Station, Weiping Xiao

Electrical Engineering Theses - Archive

Due to the price hike of the fossil fuel and the concern of the global warming, the hydrogen economy can be envisioned to address those problems. After the Energy Bill was announced in 2005, a transition of national energy system from hydrocarbon to hydrogen had been recognized. However, safe and convenient refueling and widespread availability of hydrogen from various energy sources are the prerequisite for the development of hydrogen economy. This research focuses on the hydrogen filling station with on-site hydrogen production by electrolysis of water. The virtual wind farm and on-site installed photovoltaic (PV) supply the main and renewable …

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Battery Identification Methods Based On Equivalent Circuit Model, Matthew Cole Ragsdale Jan 2009

Battery Identification Methods Based On Equivalent Circuit Model, Matthew Cole Ragsdale

Electrical Engineering Theses - Archive

Development of an intelligent battery diagnostic system is a necessity for future transportation industry. These technologies will have the potential to create profound impact in other industries such as portable electronics. This thesis reports on battery identification methods that are primarily engineered to detect the chemistry, number of cells, and state of charge in an unknown package of batteries. The proposed methods have the potential to be used for condition monitoring in a known set of batteries thereby, creating a health monitoring apparatus that can be an integral part of a battery management system using any of the prominent lead …

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Blocking Reader: Design And Implementation Of A Low-Cost Passive Uhf Rfid Blocking Reader, Gaurov Narayanaswamy Jan 2009

Blocking Reader: Design And Implementation Of A Low-Cost Passive Uhf Rfid Blocking Reader, Gaurov Narayanaswamy

Electrical Engineering Theses - Archive

In this thesis I present a low-cost passive UHF ISO 18000-6C RadioFrequency Identification, or RFID, reader that is feasible for mobileand privacy applications. Low cost readers are necessary to achievethe promised cost savings and enhanced revenue generation that theInternet of Things promises to deliver. Low cost readers may beinstalled virtually everywhere, providing real-time asset monitoringand a host of new and innovative applications yet to be conceived.While pervasively deployed readers provide tremendous benefits, thepromiscuous nature of the 18000-6C tags means that the readers alsopose a threat to personal security and privacy. Privately owned tags on a person will be read by …

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Dlp Hyperspectral Imaging For Surgical And Clinical Utility, Robert Paul Francis Jan 2009

Dlp Hyperspectral Imaging For Surgical And Clinical Utility, Robert Paul Francis

Bioengineering Theses - Archive

Surgeons want technology to help them see differences in tissue chemistry. If they know how oxygenated tissues and organs are during medical procedures, they are more able to eliminate dangerous tissues and maintain viable organs. Hyperspectral imaging non-invasively measures the optical absorbance spectrum of each pixel in a spatial field of view and, with chemometric image processing, can visualize the spatial distribution of tissue oxygenation. Current hyperspectral imaging systems are too slow to monitor real-time physiological changes in live tissue. Therefore, a novel DLP Hyperspectral Imaging (DLP HSI) system is developed for real-time, non-invasive, in-vivo imaging of tissue chemistry in …

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A Novel Device For The Establishment Of An Animal Model Mimicking Spinal Deformity Surgery For Neurological Deficit Risk Mitigation, Bradley Elmer Jan 2009

A Novel Device For The Establishment Of An Animal Model Mimicking Spinal Deformity Surgery For Neurological Deficit Risk Mitigation, Bradley Elmer

Bioengineering Theses - Archive

Correction forces during spine deformity surgery impart significant multidirectional stress forces to the spinal cord, which in some cases result in severe damage to the spinal cord and permanent paralysis, the most feared complication. Animal models are critical for the development of neuroprotective strategies. However, those currently available are limited to contusion, transection, or unidirectional distraction injuries, which fail to replicate the multidirectional forces that occur during spine corrective surgery. In order to develop an improved model of distraction spinal cord injury we designed a device based on intervertebral grip fixation and linear actuators, capable of inducing controllable bidirectional distraction …

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In Situ Crosslinkable Polyesters For Tissue Engineering And Drug Delivery, Dipendra Raj Gyawali Jan 2009

In Situ Crosslinkable Polyesters For Tissue Engineering And Drug Delivery, Dipendra Raj Gyawali

Bioengineering Theses - Archive

In situ crosslinkable elastic materials are increasingly being explored for various biomedical applications such as drug delivery and tissue engineering due to their site specific nature. The creation of an in situ crosslinkable elastomer rich in pendant chemistry has been a challenge in the field of biomaterials. Herein, we have developed two new in situ biodegradable materials: poly(octamethylene maleate citrates) (POMC) and poly(poly(ethylene glycol) maleate citrate) (PPEGMC). These materials are all low molecular weight in their pre-polymeric form, which shows their potential to be used as an injectable biomaterial. The preservation of pendant carboxylic and hydroxyl groups in these polymeric …

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Development Of An Optical Spectroscopic Method To Detect Neurohemodynamic Changes Induced By Pain In Rats, Sweta Narvenkar Jan 2009

Development Of An Optical Spectroscopic Method To Detect Neurohemodynamic Changes Induced By Pain In Rats, Sweta Narvenkar

Bioengineering Theses - Archive

In my optical spectroscopy study, multi-channel, thin optical probes with short source-detector separation have been implemented, calibrated, and used along with a multi-channel spectrometer as a quantitative technique to observe changes in vascular hemoglobin concentration and hemoglobin oxygen saturation as well as light scattering of tissues. Each of the four needle probes used in my study consists of two bifurcated fibers; one fiber is connected to a halogen light source and the other fiber to a CCD-array spectrometer having a spectral window from 450 nm to 900 nm. Each fiber is 100 micron in diameter. As we utilized the four …

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Integration Of Data Mining Algorithms And Control Charts For Multivariate And Autocorrelated Processes, Weerawat Jitpitaklert Jan 2009

Integration Of Data Mining Algorithms And Control Charts For Multivariate And Autocorrelated Processes, Weerawat Jitpitaklert

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

The objective of this dissertation is to integrate state-of-the-art data mining algorithms with statistical process control (SPC) tools to achieve efficient monitoring in multivariate and autocorrelated process. Process monitoring and diagnosis have been widely recognized as important and critical tools in system monitoring for detection of abnormal behavior and quality improvement. Although traditional SPC tools are effective in simple manufacturing processes that generate a small volume of independent data, these tools are not capable of handling the large streams of multivariate and autocorrelated data found in modern manufacturing/service systems. As the limitations of SPC methodology become increasingly obvious in the …

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Nonlinear Dynamic Analysis Of Hybrid Frames, Dobrinka Radulova Jan 2009

Nonlinear Dynamic Analysis Of Hybrid Frames, Dobrinka Radulova

Civil Engineering Theses - Archive

This study proposes a hybrid frame system consisting of rigid and semi-rigid connections subjected to a dynamic loading. Two building geometries are chosen to represent low-rise and high-rise buildings. Multiple locations for placement of semi-rigid connections are proposed, and the hybrid systems with the most efficient energy dissipation are identified. During this analysis, five earthquake records are used to provide a spectrum of frequencies. Five practical semi-rigid connection types and one connection with analytical parameters are also modeled into the selected hybrid combinations by applying zero-length springs at the ends of beams, in which their nonlinear constitutive relation is defined …

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Theia: Radio Frequency Identification Performance Analysis Tool, Jason Francis Pereira Jan 2009

Theia: Radio Frequency Identification Performance Analysis Tool, Jason Francis Pereira

Electrical Engineering Theses - Archive

In recent years there has been an increase in the adoption of Radio FrequencyIdentication or RFID systems for most applications that deal with investment (products/people) tracking. The ideal requirements of investment tracking systems are :-lost-cost, zero maintenance and eciency.Although the applications are similar in nature, the scenarios and operating environmentsare not. This is a problem that plagues an inexpert consumer of RFIDsystems. RFID systems are application specic and hence have to be properly customizedto the application environment. One solution to this problem is to have theinstallation set up by an expert, but this is impractical due to recurring costs for …

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Implementation Of Autonomous Navigation And Obstacle Avoidance On An Unmanned Ground Vehicle, Pranav Naresh Desai Jan 2009

Implementation Of Autonomous Navigation And Obstacle Avoidance On An Unmanned Ground Vehicle, Pranav Naresh Desai

Electrical Engineering Theses - Archive

This thesis presents the implementation of a novel distributed embedded systems approach to real-time obstacle avoidance and guidance for an Unmanned Ground Vehicle (UGV). The mobility, real-time, and limited size requirements of UGVs, result in computationally limited and resource constrained hardware platform. The use of distributed computational resources, such as multiple embedded micro-controllers, enables the distribution of the computing resources for obstacle avoidance and guidance system functionalities. The resulting system's complexity is significantly greater than that of a single high performance processor performing all of the above functions. The hardware platform is integrated with sensors and micro-controllers to function as …

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Design And Study Of Phase Locked Loop For Space Applications In Sub-Micron Cmos Technology, Partha Pratim Ghosh Jan 2009

Design And Study Of Phase Locked Loop For Space Applications In Sub-Micron Cmos Technology, Partha Pratim Ghosh

Electrical Engineering Dissertations - Archive

This work proposes a successful design of a radiation hard phase locked loop (PLL) using Silicon-on-Sapphire CMOS (SOS) technology for space applications. A fully self-bias radiation hard PLL providing frequency of 2.5 GHz has been designed for the first time on SOS technology. SOS technology is used to provide radiation hardness from Single Event Effects (SEE), an improvement over the use of commercially available bulk CMOS process. Innovative designs of VCO implemented in the PLL, architectural modifications in the use of buffers, bias stages, asynchronous dividers and optimization of fully self-bias design provide hardness from Total Ionization Dose (TID). Self-bias …

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Designing Multi-Objective Reverse Logistics Networks Using Genetic Algorithms, Sanya Yimsiri Jan 2009

Designing Multi-Objective Reverse Logistics Networks Using Genetic Algorithms, Sanya Yimsiri

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Reverse logistics (RL) involves management of activities that include collection, sort/storage, transportation, recovery, disposal and re-distribution. The product return process is more complicated than forward logistics due to presence of multiple reverse distribution channels, individualized returns with small quantities, extended order cycles associated with product exchanges and a variety of recovery and disposition options. Reverse logistics has been gaining interest from many sectors due to rising costs, environmental concern and tougher regulations. As a result, good reverse logistics network design can help business save costs and meet their bottom lines in this competitive global environment. Most of the previous research …

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Physiological Telemetric Sensing Systems For Medical Applications, Lun-Chen Hsu Jan 2009

Physiological Telemetric Sensing Systems For Medical Applications, Lun-Chen Hsu

Electrical Engineering Dissertations - Archive

A batteryless, wireless, sensing system, suitable for biomedical applications, was studied in this dissertation. The sensing system contains a reader and a transponder and the working principle is based on passive RFID systems. The transponder harvests the RF energy from the reader to power up the frequency generator circuit which is modulated by sensor signals. Sensor signals are encoded into frequency shifts to provide the immunity to motion artifacts and the robust performances of sensing system are demonstrated. The sensing platform can also be used for multiple sensor integration for different medical applications. In this dissertation, the physiological measurements are …

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Effects Of Voltage Unbalance And System Armonics On The Performance Of Doubly Fed Induction Wind Generators, Morgan Mozhgan Kiani Jan 2009

Effects Of Voltage Unbalance And System Armonics On The Performance Of Doubly Fed Induction Wind Generators, Morgan Mozhgan Kiani

Electrical Engineering Dissertations - Archive

Inherent difficulties in management of electric power in the presence of an increasing demand for more energy, non-conventional loads such as digital appliances, and non-sustainable imported fossil fuels has initiated a multi-folded effort by many countries to restructure the way electric energy is generated, dispatched, and consumed. Smart power grid is the manifestation of many technologies that would eventually transforms the existing power grid into a more flexible, fault resilient, and intelligent system. Integration of distributed renewable energy sources plays a central role in successful implementation of this transformation. Among the renewable options, wind energy harvesting offers superior engineering and …

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Dynamic Scene Interpretation And Understanding From Two Views, Ninad Shashikant Thakoor Jan 2009

Dynamic Scene Interpretation And Understanding From Two Views, Ninad Shashikant Thakoor

Electrical Engineering Dissertations - Archive

Interpretation of a static or dynamic scene starts by segmenting the scene followed by recognition. Our work concentrates on the general problem of segmenting and recognizing animate and inanimate objects in a scene captured from two different views. The two views here refer to either a pair of frames captured by a stereo camera or two frames (with spatial overlap) captured with a moving camera.The work described in the dissertation starts with an iterative split-and-merge framework for segmentation of an unknown number of objects captured with stereo camera. The disparity of a scene is modeled by approximating various surfaces in …

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A Novel Method For Major Harmonic Sources Identification In High Voltage Transmission Systems, Shun Liang Jan 2009

A Novel Method For Major Harmonic Sources Identification In High Voltage Transmission Systems, Shun Liang

Electrical Engineering Dissertations - Archive

Due to the proliferation of high-voltage power electronics devices and nonlinear loads connected to power systems, the penetration of produced harmonics into power transmission networks to pollute power quality of power systems has been a new concern. Recently, an electric utility company in Texas has observed that harmonic levels may exceed the recommended levels of IEEE Std. 519-1992 at some points in the 138 kV, 161 kV, and 345 kV transmission systems. In order to meet the requirement of the IEEE recommended practice and maintain the power quality of electricity delivered to consumers, identification of major harmonic sources to mitigate …

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Electrodeposited Cuprous Oxide Solar Cells, Kunhee Han Jan 2009

Electrodeposited Cuprous Oxide Solar Cells, Kunhee Han

Electrical Engineering Dissertations - Archive

The electrochemically deposited cuprous oxide (Cu2O) as a photovoltaic absorber material is introduced in this work. The electrical, structural, and optical characteristics of electrodeposited Cu2O are well investigated. The pH of the deposition solution controls the flat band voltage of Cu2O. The variation of the flat band voltage by solution pH is related to oxygen incorporation in the film, which is controlled by the amount of oxygen precursor, OH-, in the solution. Hence, the high pH in the solution is preferable for producing a p-type Cu2O with copper vacancy, while the low pH in the solution is preferable for producing …

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Mems Based Wireless Sensing And Therapeutic Systems For Biomedical Applications, Praveen Pandojirao-Sunkojirao Jan 2009

Mems Based Wireless Sensing And Therapeutic Systems For Biomedical Applications, Praveen Pandojirao-Sunkojirao

Electrical Engineering Dissertations - Archive

Miniaturized devices in vivo for accurate diagnosis and prognosis in therapy to detect various physiological parameters inside human body have been a goal for efficient healthcare. In this perspective, microelectromechanical system (MEMS) devices providing small size features and new transduction functions benefit such biomedical applications. The features in MEMS devices also allow integration of CMOS circuitry and wireless communication for electronic control as well as actuation functionalities for driving mechanical parts for scanning, moving and probing. In this work, feasibility studies for two novel sensing systems: an in vivo optical fiber based spectral optical coherence tomography (OCT) imaging system and …

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A Hybrid Method For Identifying And Estimating Key Dynamic Parameters For Exciters, Pss And Governors Based On Event-Recorded Measurements On-Line Measurements, Yunzhi Cheng Jan 2009

A Hybrid Method For Identifying And Estimating Key Dynamic Parameters For Exciters, Pss And Governors Based On Event-Recorded Measurements On-Line Measurements, Yunzhi Cheng

Electrical Engineering Dissertations - Archive

Following the power market deregulation, power systems have become more complex and are found to be consistently operating closer to their stability limits. Power system dynamic modeling and studies which provide significant insight into the dynamic characteristics of the system are bound to play increasingly critical roles. The dynamic simulation results are highly dependent on certain key parameters that govern the dynamics of the power system such as governors and/or exciters in the case of generation facilities. However, the dynamic parameters in the system database maintained by the Independent System Operator (ISO) are not accurate due to numerous reasons ranging …

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A Family Of Robust Second Order Training Algorithms, Sanjeev Sreenivasa Rao Malalur Jan 2009

A Family Of Robust Second Order Training Algorithms, Sanjeev Sreenivasa Rao Malalur

Electrical Engineering Dissertations - Archive

Starting with the concept of equivalent networks, a framework for analyzing the effect of linear dependence on training of a multi-layer perceptron is established. Detailed mathematical analyses are carried out to show that training using backpropagation and Newton's method is different under the presence of linear dependence.Two effective batch training algorithms are developed for the multilayer perceptron. First, the optimal input gain algorithm is presented, which computes an optimal gain coefficient for each input, used to update the input weights. The motivation for this algorithm comes from using equivalent networks to analyze the effect of input transformation. It is shown …

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Open Main Detection In Underground Distribution Network Using Statistical Approaches, Abedalgany Abedallah Athamneh Jan 2009

Open Main Detection In Underground Distribution Network Using Statistical Approaches, Abedalgany Abedallah Athamneh

Electrical Engineering Dissertations - Archive

The continuous increase for people dependency on electrical energy to run most of their industrial, commercial and residential activities makes it necessary to regularly improve the distribution systems. This Improvement does not involve served area and system capacity increase only, but also includes service quality and system reliability enhancement. Outage is the most serious challenge that might affect the reliability of the distribution system, especially in the congested areas like New York City, where the outage is a threat for continuity of service for a large number of customers or for the important world institutions there. Outage incident in distribution …

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Objective Image And Video Quality Assessment With Applications, Qiang Li Jan 2009

Objective Image And Video Quality Assessment With Applications, Qiang Li

Electrical Engineering Dissertations - Archive

Objective Image and Video Quality Assessment (IQA/VQA) aims to automatically measure the quality degradation perceived by the human eyes. It is of fundamental importance to address a wide variety of problems in image and video processing. Based on the availability of the information about the reference image, IQA/VQA models can be classified into Full-reference (FR), Reduced-reference (RR) and No-reference (NR) IQA/VQA methods. This dissertation focuses on FRIQA/VQA, RRIQA/VQA, as well as their applications in perceptual image coding and video interpolation.First, we propose novel metrics for FRIQA/VQA based on Structural SIMilarity (SSIM) and the information theoretical weighting. The spatial information weights …

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Performance Evaluation In Reverse Logistics With Data Envelopment Analysis, Ake Tonanont Jan 2009

Performance Evaluation In Reverse Logistics With Data Envelopment Analysis, Ake Tonanont

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Good reverse logistics design can save cost, increase revenues, and gain competitive edges over the rivals. Design of the optimized reverse supply chain model is a very important task to help enterprises save cost and gain benefits from their supply chains. In this study, reverse logistics is considered as a part of the Closed Loop Supply Chain (CLSC). CLSC combines forward and reverse flow together in the supply chain. Each component in a forward and reverse supply chain results in the efficiency of CLSC. Therefore, considering forward and reverse supply chain together as a CLSC will result in more benefits …

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Software Capacity Planning: A Methodology For A Portfolio Of High Technology Product Development Projects, Rajiv Malhotra Jan 2009

Software Capacity Planning: A Methodology For A Portfolio Of High Technology Product Development Projects, Rajiv Malhotra

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

High technology product development projects make extensive use of engineering software during the product development process. The suite of engineering software tools deployed during product development represents a significant portion of the product development costs. The ability to forecast the engineering software license capacity required to support product development plans is crucial for budgeting, return on investment (ROI) calculations, contract negotiations with the software suppliers, and the provision of an IT infrastructure necessary to support the execution of the software tools. This research shows that the usage of engineering application software in high technology is cyclical due to the characteristics …

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Multi-Port Power Electronic Interface For Renewable Energy Sources, Wei Jiang Jan 2009

Multi-Port Power Electronic Interface For Renewable Energy Sources, Wei Jiang

Electrical Engineering Dissertations - Archive

Energy intensive products and services are penetrating people's daily life as well as different sectors of industry during recent decades. Further effort to improve efficiency, reduce green house gas and hazardous particle emission lead to the emergence of the "more electric" concept in several industries including transportation. This trend, however, burdens the aging power system and existing local power networks. To offer a remedy to the problem and a smooth transition to a more reliable, more diverse, and more efficient power grid of the future, the concept of Multi-port Power Electronic Interface (MPEI) for localized power processing is introduced in …

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Millimeter Scale Robots For The Nanofactory, Rakesh Murthy Jan 2009

Millimeter Scale Robots For The Nanofactory, Rakesh Murthy

Electrical Engineering Dissertations - Archive

The top down approach is a commonly employed miniaturization pathway into micro and nanomanufacturing. Its popularity is due to the fact that it adapts traditionally engineered macro scale positioning, manipulation and processing technology with micro and nano scale precision and part sizes. However, state of the art top down systems such as the Atomic Force Microscope (AFM) span four to five orders of magnitude larger than the parts being handled. This dissertation addresses the need for creating millimeter size robotic positioning technology that closes the size gap between equipment and part sizes. Such microrobot manufacturing methodology comprising of micro component-level …

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Online Adaptive Optimal Control For Continuous-Time Systems, Draguna Vrabie Jan 2009

Online Adaptive Optimal Control For Continuous-Time Systems, Draguna Vrabie

Electrical Engineering Dissertations - Archive

This work makes two major contributions. * First, in the field of computational intelligence, it develops reinforcement learning controllers (i.e. approximate dynamic programming algorithms) for continuous-time systems, whereas in the past, reinforcement learning has been mainly developed for discrete-time systems. * Second, in the field of control systems engineering, it develops on-line optimal adaptive controllers, whereas in the past, optimal control has been an off-line design tool, and on-line adaptive controllers have not been optimal. The online algorithms presented herein are reinforcement learning schemes which provide online synthesis of optimal control for a class of nonlinear systems with unknown drift …

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Automated 3d Microassembly With Precision Adjusted Hybrid Supervisory Controller, Choudhury Aditya Narayan Das Jan 2009

Automated 3d Microassembly With Precision Adjusted Hybrid Supervisory Controller, Choudhury Aditya Narayan Das

Electrical Engineering Dissertations - Archive

Unlike semiconductor integrated circuits (ICs), newer microsystems combine sensors, actuators, mechanical structures, electronics, and optics on a single substrate. In such a diversified system, heterogeneous manipulation of the components becomes unavoidable. In an effort to find a solution to reduced yields and speeds in manufacturing at the micro-scale, research initiated in 1990s has sought to understand top-down aspects of micromanipulation, sensor-based precision control of robots, self alignment effects using compliant micro structure designs, and so on. From these researches, automated microassembly emerges as an enabling technology for micro manufacturing that offers well-known pathways to building heterogeneous microsystems with a higher …

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