Engineering Commons^™

Timing-Pulse Measurement And Detector Calibration Of The Osteoquant, Binu Eapen Enchakalody

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The OsteoQuant is a second-generation pQCT scanner, which can provide precisedensity assessment of bone. The scanner is being upgraded with an x-ray tube radiation source and a semiconductor CZT detector. This thesis provides solutions for two issues: motion-detector timing and dead-time/beam-hardening corrections. During translation, the motion-control system of the scanner repositions the source and detector by small intervals. However, the detector collects photon counts asynchronously with respect to the motor-timing pulses and reads photon counts (frames) at regular intervals based on its own clock. Since there needs to be correspondence between source/detector location and detector readout, the first part of …

Application Of Modern Principles To Demand Forecasting For Electronics, Domestic Appliances And Accessories, Gregory Daniel Noble

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Royal Philips is a large scale producer of consumer electronics, personal appliances, lighting, and healthcare appliances. Demand data from 12 Business Units (BU) of Royal Philips was examined in the study; four business units from each of three divisions: DAP, PA, and CE. From the data supplied, different forecast techniques were evaluated to determine which procedure produces the highest quality forecasts. Three forecasting techniques were evaluated using the provided data. The three forecasting techniques evaluated are the exponential smoothing forecasting method, the exponential smoothing with a linear trend forecasting method, and the Winters forecasting method.

The Visual Basic for Applications …

Graphical User Interface (Gui) To Study Different Reconstruction Algorithms In Computed Tomography, Shital K. Abhange

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Computed tomography (CT) imaging relies on computational algorithms to reconstruct images from projections gathered from the CT scan. Depending on the scanner geometry, different types of reconstruction algorithms can be used. To study these different types of reconstruction algorithms in a user-friendly way, a software tool was built. The aim of the thesis was to provide a software platform to access a number of previously implemented reconstruction algorithms with ease and minimal knowledge of the reconstruction code. The goal was accomplished by building a Graphical User Interface (GUI) using MATLAB 7.7.0 (R2008b). In addition to creating mathematical objects and invoking …

Using Two Channel Communication To Study Selective Auditory Attention Using Air And Bone Conducted Interfaces, Kutbi Nuruddin Kaliyakuwawala

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The purpose of this study was to evaluate the human capability to use selective auditory attention across the two different hearing pathways, air conduction and bone conduction. Four two channel communication systems were used as a basis for comparison: (1) both channels presented via headphones (left ear and right ear each represent a different channel), (2) two channels presented via loudspeakers placed at 135° and 225°, (3) one channel presented via headphones (both ears) and one channel to bone vibrator (placed at the condoyle), and (4) one channel presented via bone vibrator and one channel via loud speakers (placed at …

Visualization Methods And User Interface Design Guidelines For Rapid Decision Making In Complex Multi-Task Time-Critical Environments, Sriram Mahadevan

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Real-world scenarios are complex dynamic systems that are often overloaded with information. Effective performance of these dynamic systems depends on the objects in such systems and the relationship among them. The control of many of these systems is semi-automated. Human operators constantly monitor and control these systems, assess the situation and often make decisions under time pressure. However, this supervisory control paradigm in a dual-task environment can be a very challenging task. Existing interface design methodologies and techniques have not delved deeply enough into defining information displays for complex, dynamic, time-critical, dual-task environments with capabilities for rapid task change awareness …

The Effects Of Depth And Eccentricity On Visual Search In A Depth Display, George Angelo Reis

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The attribute of depth has been shown to provide saliency or conspicuity for items in a visual search task. Novel displays that present information in real physical depth offer potential benefits. Previous research has studied depth in visual search but depth was mostly realized without real physical separation of display elements. This study aimed to better understand the effects of real physical depth and eccentricity on visual search in a depth display. Through this understanding, we can appropriately utilize this new technology. An experiment was conducted to test four hypotheses regarding how depth, eccentricity, target feature, and screen location would …

Integrated Faceted Browser And Direct Search To Enhance Information Retrieval In Text-Based Digital Libraries, Shea-Tinn Yeh

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Browsing and searching are two prominent paradigms in information retrieval. In current digital library implementations, exploratory browsing is sometimes not available as an option. When offered, it is commonly presented as an alphabetical listing of chosen categories depending on the scope of the digital collections. In addition, users have to switch between different information spaces for browsing and searching. This research proposes an information retrieval paradigm of integrated faceted browser and direct search interfaces for text-based digital libraries. Experimental results show that compared to a conventional alphabetical browser, the faceted browser can significantly improve the effectiveness (by 30.8%, p = …

Determining The Effect Of Speaker's Gender And Speech Synthesis On Callsign Acquisition Test (Cat) Results, Jasminkumar B. Soni

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Effective and efficient speech communication is one of the leading factors for success of battlefield operation. With the increases in the levels of gender diversity in military services, it is important to assess the effectiveness of voice for both genders in communication systems. The purpose of this research study was to determine the effect of the speaker's voice (male and female) on the speech intelligibility (SI) performance of the Callsign Acquisition Test (CAT). In addition, the effects of synthesized speech were evaluated. The CAT test is a new SI test that has been developed for military use. A group of …