Engineering Commons^™

Inventory Systems With Transshipments And Quantity Discounts, Gregory Daniel Noble

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This research advances knowledge in the area of inventory systems and the relationship between competing retailers and suppliers of goods. This dissertation studies retailers that face uncertainty in the demand for goods and who purchase the goods from a single supplier. A game theoretic methodology is developed to analyze supplier pricing decisions and retailer quantity decisions and interactions in a competitive transshipment system where quantity discounts are offered. The system studied differs from previous work in the subject by introducing quantity discounts from supplier to retailer into a system of competitive retailers that transship stock. Analysis of these systems focuses …

Traffic Surveillance Using Low Cost Continuous Wave (Cw) Doppler Radars, Wu Yang

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Low cost un-modulated continuous wave (CW) radar (CW Doppler radar) can be used to measure the speed of a vehicle. Traditionally, a radar gun, a lidar gun or a speed camera is used to capture a speeding vehicle. A radar gun can either measure the fastest vehicle or the vehicle with the strongest reflection. If a radar gun is used, a police officer must determine which vehicle has the speed shown on the screen of the radar gun. A lidar gun can precisely detect a speeding vehicle, but it requires precise aiming. When a camera is used, a picture will …

Managing Patient Test Data In Primary Care: Developing And Evaluating A System For Test Tracking To Enhance Processes, Safety, And Understanding Of Performance, Jennifer M. Cloud-Buckner

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Patient testing is vital for primary care and serves as a gateway to specialty healthcare. Patient safety is worsened when testing orders (e.g., laboratory, imaging orders) are not tracked, results are lost, or abnormal results lack patient notification and follow-up. Non-standardized testing management reduces resilience; affects clinical outcomes; and increases errors, costs, workload, and delays.

To address the need for testing management improvements, this research followed four phases in six objectives: (1) In Phase I initial survey, assess perceptions, attitudes, and behaviors of practicing healthcare clinicians and administrators about testing, safety, and technology; (2) In Phase II system design, design …

Statistical Methods For Image Change Detection With Uncertainty, Andrew James Lingg

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Sensors capable of collecting wide area motion imagery (WAMI), video synthetic aperture radar (SAR), and other high frame rate sensor modalities provide massive amounts of high-resolution data. Such data allows for the use of multiple images in exploitation tasks which may have traditionally used single images or single pairs of images. One such task is change detection. This dissertation presents new statistical methods for change detection that provide for the exploitation of multiple images per pass. Uncertainty in image registration can degrade change detection performance. Registration accuracy is analyzed, and the impact of registration uncertainty is propagated to the registered …

An Optimization Approach To Indoor Location Problem Based On Received Signal Strength, Lei Zheng

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This research was motivated by the desire of a Fortune 100 retail company to track its customers' behaviors through the implementation of a low-cost indoor location system using received signal devices. Indoor location through received signal strength (RSS) is of low costs, yet it suffers from poor accuracy due to lack of direct line-of-sight, multi-path ratio propagation, and various interferences. To improve its location estimation accuracy, therefore, we propose a mathematical programming based propagation approach for RSS based location systems. The core of our approach is an optimization model that minimizes the sum of squared errors of signal strength. In …

Steady-State And Small-Signal Modeling Of A Pwm Dc-Dc Switched-Inductor Buck-Boost Converter In Ccm, Julie Joann Lee

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Pulse-width modulated (PWM) buck-boost converters have a significant role in power electronic systems for renewable energy applications. A new hybrid, the switched-inductor buck-boost converter, is superior to the conventional buck-boost because it uses less energy in the magnetic field, has smaller component size of inductors, and produces less current stresses in the switching elements. Steady-state and dynamic modeling of the switched-inductor buck-boost converter is essential to design and implement of a feed-back network. The objective of this work is to present the steady-state analysis of a PWM switched-inductor buck-boost dc-dc converter operating in continuous conduction mode (CCM). The idealized voltage …

Nanostructured Columnar Thin Films Using Oblique Angle Deposition: Growth, Sers Characterization And Lithographic Processing, Piyush J. Shah

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Oblique angle physical vapor deposition technique has led to the evolution of new class of nanostructured thin films. These films posses' novel anisotropic electrical, magnetic, optical, properties which could be potentially engineered based on the growth conditions and the deposition parameters. The technique is based on the atomistic level self-shadowing principle. In the oblique angle deposition (OAD) technique, the substrate is held at an oblique angle with respect to the incoming vapor flux. As the vapor atoms condense and nucleate on the substrate, the shadowed regions behind each site stop receiving the subsequent vapor atoms. Instead, they land on the …

Quantification Of Multiple Types Of Uncertainty In Physics-Based Simulation, Inseok Park

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In general, more than one simulation model can be created to analyze and design engineering systems. Uncertainty is inevitably involved in selecting a single best approximating model from among a set of simulation models. Uncertainty in model selection (called model-form uncertainty in the present research) cannot be ignored, especially when the differences between the predictions by plausible models are significant. Also, each simulation model involves uncertainty in its input parameters and unknown errors in its predictions of system responses. A methodology is developed to quantify model-form uncertainty using the differences between experimental data measured from an engineering system and model …

Fabrication And Testing Of Hierarchical Carbon Nanostructures For Multifunctional Applications, Ian Timothy Barney

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Multi-scale hierarchical carbon structures have been developed by growing strongly attached carbon nanotubes (CNT) on high surface area substrates having open, interconnected porosity. This investigation was developed on cellular carbon foams but the process is equally suitable for other geometries including flat, fibers, and other porous substrates (interconnected). It is also adaptable to other substrate materials such as metals, alloys or ceramic compounds. Multiwalled carbon nanotubes are grown using a floating catalyst chemical vapor deposition (CVD) method after pre-coating the substrate with a silica nano-layer. The silica-coated graphitic substrates are seen to grow 280 times more nanotubes per unit area …

Stead-State And Small-Signal Modeling Of Power-Stage Of Pwm Z-Source Converter, Veda Prakash Nagabhushana Galigekere

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Pulse-width modulated (PWM) Z-source converter plays an important role in industrial/power electronic systems. Steady-state and dynamic modeling of the power-stage of PWM converters is essential for envisaging a closed-loop regulated power supply.

Steady-state analysis of pulse-width modulated (PWM) Z-source dc-dc converter operating in continuous conduction mode (CCM) is presented. Voltage and current waveforms, and their corresponding expressions describing the steady-state operation of the PWM Z-source dc-dc converter have been presented. The input-to-output dc voltage transfer functions, both for ideal and non-ideal PWM Z-source dc-dc converter have been derived. The minimum Z-network inductance required to ensure CCM operation is derived. The …

The Demonstration Of Smse Based Cognitive Radio In Mobile Environment Via Software Defined Radio, Ruolin Zhou

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With the emergence of increasing number of wireless devices and demands for higher data rates, spectrum crowding and congestion increases. Spectrum congestion problem has been challenging wireless communication engineers for a few decades. However, recent studies indicate that most of the time wide ranges of the radio spectrum are rarely utilized. Hence, the spectrum congestion is mainly due to the inefficient spectrum usage rather than the spectrum scarcity. To exploit under used spectrum and utilize the spectrum efficiently in dynamically changing environments, a new technology is needed. Cognitive Radio (CR) arises to be a possible solution to spectral crowding problem …

Turbine Base Pressure Active Control Through Trailing Edge Blowing, Bayindir Huseyin Saracoglu

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The desire for high performance and low fuel consumption aero-engines has been pushing the limits of the turbomachinery and leading cutting-edge engine designs to fulfill the demand. The number of stages is reduced to achieve the same pressure ratios over lighter turbines. The extreme expansion requirements result in transonic-supersonic flow fields. Transonic and supersonic turbines are exposed to the shock waves that appear at the trailing edge of the airfoils, generating substantial efficiency deduction due to the interaction with the boundary layer. Furthermore, pressure fluctuations created by the shocks result in unsteady forcing on downstream components and eventually cause high …

Characterization And Modelling Of Laser Micro-Machined Metallic Terahertz Wire Waveguides, Satya Rama Naga Lakshmi Ganti

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Terahertz radiation, a region in the electromagnetic spectrum which lies between the microwave and infrared, has gained considerable attention recently due to interesting properties exhibited by materials exposed to this radiation. Dielectric materials such as glass, paper, plastic, and ceramics that are usually opaque at optical frequencies are transparent to terahertz radiation. This led to interesting terahertz spectroscopy and imaging applications. Finite element method simulations of plain, tapered and periodically corrugated metal terahertz wire waveguides have been conducted at the end of the waveguides. This modeling was used to guide the choice of design parameters for the fabrication of waveguides …

Frequency Modulated Continuous Wave Radar And Video Fusion For Simultaneous Localization And Mapping, Andrew Stephen Kondrath

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There has been a push recently to develop technology to enable the use of UAVs in GPS-denied environments. As UAVs become smaller, there is a need to reduce the number and sizes of sensor systems on board. A video camera on a UAV can serve multiple purposes. It can return imagery for processing by human users. The highly accurate bearing information provided by video makes it a useful tool to be incorporated into a navigation and tracking system. Radars can provide information about the types of objects in a scene and can operate in adverse weather conditions. The range and …