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Articles 2851 - 2880 of 4566

Full-Text Articles in Engineering

Optimizing The High Dynamic Range Imaging Pipeline, Ahmet Oguz Akyuz Jan 2007

Optimizing The High Dynamic Range Imaging Pipeline, Ahmet Oguz Akyuz

Electronic Theses and Dissertations

High dynamic range (HDR) imaging is a rapidly growing field in computer graphics and image processing. It allows capture, storage, processing, and display of photographic information within a scene-referred framework. The HDR imaging pipeline consists of the major steps an HDR image is expected to go through from capture to display. It involves various techniques to create HDR images, pixel encodings and file formats for storage, tone mapping for display on conventional display devices and direct display on HDR capable screens. Each of these stages have important open problems, which need to be addressed for a smoother transition to an …

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Signal Processing Of An Ecg Signal In The Presence Of A Strong Static Magnetic Field, Aditya Gupta Jan 2007

Signal Processing Of An Ecg Signal In The Presence Of A Strong Static Magnetic Field, Aditya Gupta

Electronic Theses and Dissertations

This dissertation addresses the problem of elevation of the T wave of an electrocardiogram (ECG) signal in the magnetic resonance imaging (MRI). In the MRI, due to the strong static magnetic field the interaction of the blood flow with this strong magnetic field induces a voltage in the body. This voltage appears as a superimposition at the locus of the T wave of the ECG signal. This looses important information required by the doctors to interpret the ST segment of the ECG and detect diseases such as myocardial infarction. This dissertation aims at finding a solution to the problem of …

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Studies Of A Quantum Scheduling Algorithm And On Quantum Error Correction, Feng Lu Jan 2007

Studies Of A Quantum Scheduling Algorithm And On Quantum Error Correction, Feng Lu

Electronic Theses and Dissertations

Quantum computation has been a rich field of study for decades because it promises possible spectacular advances, some of which may run counter to our classically rooted intuitions. At the same time, quantum computation is still in its infancy in both theoretical and practical areas. Efficient quantum algorithms are very limited in number and scope; no real breakthrough has yet been achieved in physical implementations. Grover's search algorithm can be applied to a wide range of problems; even problems not generally regarded as searching problems can be reformulated to take advantage of quantum parallelism and entanglement leading to algorithms which …

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Network Performance Management Using Application-Centric Key Performance Indicators, Susan Mcgill Jan 2007

Network Performance Management Using Application-Centric Key Performance Indicators, Susan Mcgill

Electronic Theses and Dissertations

The Internet and intranets are viewed as capable of supplying "Anything, Anywhere, Anytime" and e-commerce, e-government, e-community, and military C4I are now deploying many and varied applications to serve their needs. Network management is currently centralized in operations centers. To assure customer satisfaction with the network performance they typically plan, configure and monitor the network devices to insure an excess of bandwidth, that is overprovision. If this proves uneconomical or if complex and poorly understood interactions of equipment, protocols and application traffic degrade performance creating customer dissatisfaction, another more application-centric, way of managing the network will be needed. This research …

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Learning Human Behavior From Observation For Gaming Applications, Christopher Moriarty Jan 2007

Learning Human Behavior From Observation For Gaming Applications, Christopher Moriarty

Electronic Theses and Dissertations

The gaming industry has reached a point where improving graphics has only a small effect on how much a player will enjoy a game. One focus has turned to adding more humanlike characteristics into computer game agents. Machine learning techniques are being used scarcely in games, although they do offer powerful means for creating humanlike behaviors in agents. The first person shooter (FPS), Quake 2, is an open source game that offers a multi-agent environment to create game agents (bots) in. This work attempts to combine neural networks with a modeling paradigm known as context based reasoning (CxBR) to create …

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Exploring The Potential Of Combining Ramp Metering And Variable Speed Limit Strategies For Alleviating Real-Time Crash Risk On Urban Freeways, Kirolos Maged Haleem Jan 2007

Exploring The Potential Of Combining Ramp Metering And Variable Speed Limit Strategies For Alleviating Real-Time Crash Risk On Urban Freeways, Kirolos Maged Haleem

Electronic Theses and Dissertations

Research recently conducted at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical and neural networks models that are capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as real-time traffic data obtained by loop detectors. Since these models use real-time traffic data, they are capable of calculating rear-end and …

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Urban Infilling Impacts On Florida Solid Waste Facilities, Ravi Chander Nalamothu Jan 2007

Urban Infilling Impacts On Florida Solid Waste Facilities, Ravi Chander Nalamothu

Electronic Theses and Dissertations

Increasing urbanization in the US is leading to development or re-development of lands adjacent to solid waste facilities and these lands are being considered for residential communities and commercial projects. Thus, the potential for nuisance complaints against the pre-existing solid waste facility operations has become an increasing reality. The objective of this study was to develop a methodology to gather scientific and quantifiable data related to potential nuisances caused by landfills to determine setbacks and buffer zones near landfill and transfer station operations. Appropriate recommendations for these setbacks were made from case studies conducted at two landfills in Florida. The …

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Mechanisms Of Lifetime Improvement In Thermal Barrier Coatings With Hf And/Or Y Modification Of Cmsx-4 Superalloy Substrates, Jing Liu Jan 2007

Mechanisms Of Lifetime Improvement In Thermal Barrier Coatings With Hf And/Or Y Modification Of Cmsx-4 Superalloy Substrates, Jing Liu

Electronic Theses and Dissertations

In modern turbine engines for propulsion and energy generation, thermal barrier coating (TBCs) protect hot-section blades and vanes, and play a critical role in enhancing reliability, durability and operation efficiency. In this study, thermal cyclic lifetime and microstructural degradation of electron beam physical vapor deposited (EB-PVD) Yttria Stabilized Zirconia (YSZ) with (Ni,Pt)Al bond coat and Hf- and/or Y- modified CMSX-4 superalloy substrates were examined. Thermal cyclic lifetime of TBCs was measured using a furnace thermal cycle test that consisted of 10-minute heat-up, 50-minute dwell at 1135C, and 10-minute forced-air-quench. TBC lifetime was observed to improve from 600 cycles to over …

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An Algorithm For Determining Satellite Attitude By Comparing Physical Feature Models To Edges Detected In Satellite Or Ground-Based Telescope Imagery, Eric Brian Reinhart Jan 2007

An Algorithm For Determining Satellite Attitude By Comparing Physical Feature Models To Edges Detected In Satellite Or Ground-Based Telescope Imagery, Eric Brian Reinhart

Electronic Theses and Dissertations

This thesis discusses the development and performance of an algorithm created to calculate satellite attitude based on the comparison of satellite "physical feature" models to information derived from edge detection performed on imagery of the satellite. The quality of this imagery could range from the very clear, close-up imagery that may come from an unmanned satellite servicing mission to the faint, unclear imagery that may come from a ground-based telescope investigating a satellite anomaly. Satellite "physical feature" models describe where an edge is likely to appear in an image. These are usually defined by physical edges on the structure of …

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Fate Of Nitrogen And Phosphorus Species From A Black And Goldtm Nugget Mix In A Laboratoy Column Simulated Septic Tank Drainfiel, Timir Shah Jan 2007

Fate Of Nitrogen And Phosphorus Species From A Black And Goldtm Nugget Mix In A Laboratoy Column Simulated Septic Tank Drainfiel, Timir Shah

Electronic Theses and Dissertations

The presence of nitrates and phosphorus in ground water is a worldwide problem. A septic tank with drainfield that is conventionally designed does not typically remove nitrogen in the form of nitrates. The main risks are in "Blue baby" syndrome and suspected carcinogenic effect of nitrates on humans and the nutrient enrichment of receiving waters. In some areas nitrate and phosphorus removal are essentially required. Thus the information in this report concentrates on using media in the drainfield for the removal of nitrogen and phosphorus. Extensive work has been conducted in the past few decades in order to find suitable …

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Image-Space Approach To Real-Time Realistic Rendering, Musawir Shah Jan 2007

Image-Space Approach To Real-Time Realistic Rendering, Musawir Shah

Electronic Theses and Dissertations

One of the main goals of computer graphics is the fast synthesis of photorealistic image of virtual 3D scenes. The work presented in this thesis addresses this goal of speed and realism. In real-time realistic rendering, we encounter certain problems that are difficult to solve in the traditional 3-dimensional geometric space. We show that using an image-space approach can provide effective solutions to these problems. Unlike geometric space algorithms that operate on 3D primitives such as points, edges, and polygons, image-space algorithms operate on 2D snapshot images of the 3D geometric data. Operating in image-space effectively decouples the geometric complexity …

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An Economic Framework For Resource Management And Pricing In Wireless Networks With Competitive Service Providers, Shamik Sengupta Jan 2007

An Economic Framework For Resource Management And Pricing In Wireless Networks With Competitive Service Providers, Shamik Sengupta

Electronic Theses and Dissertations

A paradigm shift from static spectrum allocation to dynamic spectrum access (DSA) is becoming a reality due to the recent advances in cognitive radio, wide band spectrum sensing, and network aware real--time spectrum access. It is believed that DSA will allow wireless service providers (WSPs) the opportunity to dynamically access spectrum bands as and when they need it. Moreover, due to the presence of multiple WSPs in a region, it is anticipated that dynamic service pricing would be offered that will allow the end-users to move from long-term service contracts to more flexible short-term service models. In this research, we …

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A Hybrid Routing Protocol For Communications Among Nodes Withhigh Relative Speed In Wireless Mesh Networks, Nikolaos Peppas Jan 2007

A Hybrid Routing Protocol For Communications Among Nodes Withhigh Relative Speed In Wireless Mesh Networks, Nikolaos Peppas

Electronic Theses and Dissertations

Wireless mesh networks (WMN) is a new promising wireless technology which uses already available hardware and software components. This thesis proposes a routing algorithm for military applications. More specifically, a specialized scenario consisting of a network of flying Unmanned Aerial Vehicles (UAVs) executing reconnaissance missions is investigated. The proposed routing algorithm is hybrid in nature and uses both reactive and proactive routing characteristics to transmit information. Through simulations run on a specially built stand alone simulator, based on Java, packet overhead, delivery ratio and latency metrics were monitored with respect to varying number of nodes, node density and mobility. The …

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Behavior Of Variable-Length Genetic Algorithms Under Random Selection, Harold Stringer Jan 2007

Behavior Of Variable-Length Genetic Algorithms Under Random Selection, Harold Stringer

Electronic Theses and Dissertations

In this work, we show how a variable-length genetic algorithm naturally evolves populations whose mean chromosome length grows shorter over time. A reduction in chromosome length occurs when selection is absent from the GA. Specifically, we divide the mating space into five distinct areas and provide a probabilistic and empirical analysis of the ability of matings in each area to produce children whose size is shorter than the parent generation's average size. Diversity of size within a GA's population is shown to be a necessary condition for a reduction in mean chromosome length to take place. We show how a …

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Evaluating The Impact Of Oocea S Dynamic Message Signs (Dms) On Travelers Experience Using The Pre-Deployment Survey, John Hill Rogers Jan 2007

Evaluating The Impact Of Oocea S Dynamic Message Signs (Dms) On Travelers Experience Using The Pre-Deployment Survey, John Hill Rogers

Electronic Theses and Dissertations

The purpose of this thesis was to evaluate the impact of dynamic message signs (DMS) on the Orlando-Orange County Expressway Authority (OOCEA) toll road network using the Pre-Deployment DMS Survey (henceforth referred to as "pre-deployment survey"). DMS are electronic traffic signs used on roadways to give travelers information about travel times, traffic congestion, accidents, disabled vehicles, AMBER alerts, and special events. The particular DMS referred to in this study are large rectangular signs installed over the travel lanes and these are not the portable trailer mount signs. The OOCEA is currently in the process of adding several fixed DMS on …

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Gate Stack And Channel Engineering: Study Of Metal Gates And Ge Channel Devices, Ravi Todi Jan 2007

Gate Stack And Channel Engineering: Study Of Metal Gates And Ge Channel Devices, Ravi Todi

Electronic Theses and Dissertations

The continued scaling of device dimensions in complementary metal oxide semiconductor (CMOS) technology within the sub-100 nm region requires an alternative high dielectric constant (high-k) oxide layer to counter high tunneling leakage currents, a metallic gate electrode to address polysilicon depletion, boron penetration and high polysilicon sheet resistance, and high mobility channel materials to boost the CMOS performance. Metal gates can also offer improved thermal and chemical stability, but their use requires that we improve our understanding of how the metal alloy phase, crystallographic orientation, and composition affect the electronic properties of the metal alloy-oxide interface. To replace n++ and …

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Target Element Sizes For Finite Element Tidal Models From A Domain-Wide, Localized Truncation Error Analysis Incorporating Botto, Denwood Parrish Jan 2007

Target Element Sizes For Finite Element Tidal Models From A Domain-Wide, Localized Truncation Error Analysis Incorporating Botto, Denwood Parrish

Electronic Theses and Dissertations

A new methodology for the determination of target element sizes for the construction of finite element meshes applicable to the simulation of tidal flow in coastal and oceanic domains is developed and tested. The methodology is consistent with the discrete physics of tidal flow, and includes the effects of bottom stress. The method enables the estimation of the localized truncation error of the nonconservative momentum equations throughout a triangulated data set of water surface elevation and flow velocity. The method's domain-wide applicability is due in part to the formulation of a new localized truncation error estimator in terms of complex …

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A Comparison And Evaluation Of Common Pid Tuning Methods, Justin Youney Jan 2007

A Comparison And Evaluation Of Common Pid Tuning Methods, Justin Youney

Electronic Theses and Dissertations

The motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring the system into the required design criteria. The purpose here is to find out which tuning technique will yield the lowest …

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A Framework For The Assessment And Analysis Of Multi-Hazardsinduced Risk Resulting From Space Vehicles Operations, Serge Sala-Diakanda Jan 2007

A Framework For The Assessment And Analysis Of Multi-Hazardsinduced Risk Resulting From Space Vehicles Operations, Serge Sala-Diakanda

Electronic Theses and Dissertations

With the foreseeable increase in traffic frequency to and from orbit, the safe operation of current and future space vehicles at designated spaceports has become a serious concern. Due to their high explosive energy potential, operating those launch vehicles presents a real risk to: (1) the spaceport infrastructure and personnel, (2) the communities surrounding the spaceport and (3) the flying aircrafts whose routes could be relatively close to spaceport launch and reentry routes. Several computer models aimed at modeling the effects of the different hazards generated by the breakup of such vehicles (e.g., fragmentation of debris, release of toxic gases, …

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Negative Bias Temperature Instability And Charge Trapping Effects On Analog And Digital Circuit Reliability, Yixin Yu Jan 2007

Negative Bias Temperature Instability And Charge Trapping Effects On Analog And Digital Circuit Reliability, Yixin Yu

Electronic Theses and Dissertations

Nanoscale p-channel transistors under negative gate bias at an elevated temperature show threshold voltage degradation after a short period of stress time. In addition, nanoscale (45 nm) n-channel transistors using high-k (HfO2) dielectrics to reduce gate leakage power for advanced microprocessors exhibit fast transient charge trapping effect leading to threshold voltage instability and mobility reduction. A simulation methodology to quantify the circuit level degradation subjected to negative bias temperature instability (NBTI) and fast transient charge trapping effect has been developed in this thesis work. Different current mirror and two-stage operation amplifier structures are studied to evaluate the impact of NBTI …

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Biostability In Drinking Water Distribution Systems In A Changing Water Quality Environment Using Corrosion Inhibitors, Bingjie Zhao Jan 2007

Biostability In Drinking Water Distribution Systems In A Changing Water Quality Environment Using Corrosion Inhibitors, Bingjie Zhao

Electronic Theses and Dissertations

In this study, the bacterial growth dynamics of 14 pilot drinking water distribution systems were studied in order to observe water quality changes due to corrosion inhibitor addition. Empirical models were developed to quantity the effect of inhibitor type and dose on bacterial growth (biofilm and bulk water). Water and pipe coupon samples were taken and examined during the experiments. The coupons were exposed to drinking water at approximately 20°C for at least 5 weeks to allow the formation of a measurable quasi- steady-state biofilm. Bulk water samples were taken every week. In this study, two simple but practical empirical …

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Solar Energy For Disaster Response Using Space Program Resources, Florida Solar Energy Center, William Young Jan 2007

Solar Energy For Disaster Response Using Space Program Resources, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Satellite pictures, solar radiation levels on the earth's surface, Global Positioning Satellites (GPS) and other space-related resources are available through the efforts of many people and organizations. Satellites' measurements of these resources can be integrated with resources on earth to assess damage from disasters and evaluate resources available to respond. Space-related resources are currently being used by the American Red Cross, the Federal Emergency Management Agency, county Emergency Managers and other organizations. The widest use is in evaluating utility resources and deploying them for repair and emergency power in response to a disaster. Today's use of state-of-the-art satellite and Geographic …

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Novel Facial Image Recognition Techniques Employing Principal Component Analysis, Moataz Mahmoud Abdelwahab Jan 2007

Novel Facial Image Recognition Techniques Employing Principal Component Analysis, Moataz Mahmoud Abdelwahab

Electronic Theses and Dissertations

Recently, pattern recognition/classification has received considerable attention in diverse engineering fields such as biomedical imaging, speaker identification, fingerprint recognition, and face recognition, etc. This study contributes novel techniques for facial image recognition based on the Two dimensional principal component analysis in the transform domain. These algorithms reduce the storage requirements by an order of magnitude and the computational complexity by a factor of 2 while maintaining the excellent recognition accuracy of the recently reported methods. The proposed recognition systems employ different structures, multicriteria and multitransform. In addition, principal component analysis in the transform domain in conjunction with vector quantization is …

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Modeling Free Chlorine And Chloramine Decay In A Pilot Distribution System, Jorge Miguel Arevalo Jan 2007

Modeling Free Chlorine And Chloramine Decay In A Pilot Distribution System, Jorge Miguel Arevalo

Electronic Theses and Dissertations

The purpose of this study was to identify the effect that water quality, pipe material, pipe size, flow conditions and the use of corrosion inhibitors would have on the rate of free chlorine and chloramine decay in distribution systems. Empirical models were developed to predict the disinfectant residual concentration with time based on the parameters that affected it. Different water treatment processes were used to treat groundwater and surface water to obtain 7 types of finished waters with a wide range of water quality characteristics. The groundwater was treated either by conventional treatment by aeration (G1) or softening (G2) or …

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Soft Switching Multi-Resonant Forward Converter Dc To Dc Application For Communications Equipment, David Marlin Bills Jan 2007

Soft Switching Multi-Resonant Forward Converter Dc To Dc Application For Communications Equipment, David Marlin Bills

Electronic Theses and Dissertations

In the field of power electronics there is always a push to create smaller and more efficient power conversion systems. This push is driven by the industry that uses the power systems, and can be realized by new semiconductor devices or new techniques. This examination describes a novel technique for a small and highly efficient method of converting relatively high DC voltage to a very low voltage for use in the telecommunications industry. A modification to the standard Forward Resonant converter results in improvements in component stress, system efficiency, response time, and control circuitry. This examination describes background information needed …

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Impact Of Zinc Orthophosphate Inhibitor On Distribution System Water Quality, Xiaotao Guan Jan 2007

Impact Of Zinc Orthophosphate Inhibitor On Distribution System Water Quality, Xiaotao Guan

Electronic Theses and Dissertations

This dissertation consists of four papers concerning impacts of zinc orthophosphate (ZOP) inhibitor on iron, copper and lead release in a changing water quality environment. The mechanism of zinc orthophosphate corrosion inhibition in drinking water municipal and home distribution systems and the role of zinc were investigated. Fourteen pilot distribution systems (PDSs) which were identical and consisted of increments of PVC, lined cast iron, unlined cast iron and galvanized steel pipes were used in this study. Changing quarterly blends of finished ground, surface and desalinated waters were fed into the pilot distribution systems over a one year period. Zinc orthophosphate …

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Processing And Study Of Carbon Nanotube / Polymer Nanocomposites And Polymer Electrolyte Materials, Muthuraman Harish Jan 2007

Processing And Study Of Carbon Nanotube / Polymer Nanocomposites And Polymer Electrolyte Materials, Muthuraman Harish

Electronic Theses and Dissertations

The first part of the study deals with the preparation of carbon nanotube/polymer nanocomposite materials. The dispersion of multi-walled carbon nanotubes (MWNTs) using trifluoroacetic acid (TFA) as a co-solvent and its subsequent use in polymer nanocomposite fabrication is reported. The use of carbon nanotube/ polymer nanocomposite system for the fabrication of organic solar cells is also studied. TFA is a strong but volatile acid which is miscible with many commonly used organic solvents. Our study demonstrates that MWNTs can be effectively purified and readily dispersed in a range of organic solvents including dimethyl formamide (DMF), tetrahydrofuran (THF), and dichloromethane when …

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Comparison Of Single Stage And Two Stage Stage Grid-Tie Inverters, Keith Mansfield Jan 2007

Comparison Of Single Stage And Two Stage Stage Grid-Tie Inverters, Keith Mansfield

Electronic Theses and Dissertations

This thesis compares two methods of designing grid-tie inverters. The first design topology is a traditional two stage approach consisting of an isolated DC-DC converter on the input followed by a high switching frequency SPWM (Sinusoidal Pulse Width Modulation) stage to produce the required low frequency sine wave output. The novel second design approach employs a similar DC-DC input stage capable of being modulated to provide a rectified sine wave output voltage/current waveform. This stage is followed by a simple low frequency switched Unfolding Stage to recreate the required sine wave output. Both of the above designs have advantages and …

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Multisensor Fusion Remote Sensing Technology For Assessing Multitemporal Responses In Ecohydrological Systems, Ammarin Makkeasorn Jan 2007

Multisensor Fusion Remote Sensing Technology For Assessing Multitemporal Responses In Ecohydrological Systems, Ammarin Makkeasorn

Electronic Theses and Dissertations

Earth ecosystems and environment have been changing rapidly due to the advanced technologies and developments of humans. Impacts caused by human activities and developments are difficult to acquire for evaluations due to the rapid changes. Remote sensing (RS) technology has been implemented for environmental managements. A new and promising trend in remote sensing for environment is widely used to measure and monitor the earth environment and its changes. RS allows large-scaled measurements over a large region within a very short period of time. Continuous and repeatable measurements are the very indispensable features of RS. Soil moisture is a critical element …

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Low Temperature Nitife Shape Memory Alloys: Actuator Engineering And Investigation Of Deformation Mechanisms Using In Situ Neutr, Vinu Krishnan Jan 2007

Low Temperature Nitife Shape Memory Alloys: Actuator Engineering And Investigation Of Deformation Mechanisms Using In Situ Neutr, Vinu Krishnan

Electronic Theses and Dissertations

Shape memory alloys are incorporated as actuator elements due to their inherent ability to sense a change in temperature and actuate against external loads by undergoing a shape change as a result of a temperature-induced phase transformation. The cubic so-called austenite to the trigonal so-called R-phase transformation in NiTiFe shape memory alloys offers a practical temperature range for actuator operation at low temperatures, as it exhibits a narrow temperature-hysteresis with a desirable fatigue response. Overall, this work is an investigation of selected science and engineering aspects of low temperature NiTiFe shape memory alloys. The scientific study was performed using in …

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