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Determining existing, possible, and preferable urban tree canopy for Austin, TexasHalter, Alan Dale 13 December 2013 (has links)
This report analyzes urban tree canopy cover (UTC) in Austin, Texas in 2006 using a Geographic Information System (GIS) geoprocessing method developed by the U.S. Forest Service. Findings reveal where UTC exists, could exist, and where it could be prioritized (physically speaking) throughout the Austin region. Results are explained through the context of natural regions and land use to further characterize the urban forest distribution with the purpose of gaining valuable big-picture insights as to where environmental benefits have resulted from local land use planning decisions, development tendencies, and forestry management practices in Austin. / text
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Tidssynkroniserade mätningar i vattenkraftstationer / Time synchronized measurements in hydropower stationsLarsson, Bertil January 2010 (has links)
<p>Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator.</p><p> </p><p>The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible.</p><p> </p><p>Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP. The network includes the concerned hydropower stations and thus can wiring from the surface be avoided. The maximum error for the server in the specific hydroelectric power station is bounded within [-4.62, 3.18] ms relative to UTC. The conclusion is that Vattenfalls NTP-network meets the requirements to distribute time. A platform from National Instruments, programmed with the graphical language LabVIEW, has been used for data acquisition. The platform is programmed to synchronize its internal clock to a NTP-server, timestamp the input signals and save the data on the internal hard drive.</p>
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Analytical and Experimental Study of a PV/Thermal Transpired CollectorVeronique, Delisle January 2008 (has links)
In the last few years, unglazed transpired solar collectors (UTCs) have proven to be an effective and viable method of reducing HVAC loads and building energy consumption. With the growing interest in PV/Thermal collectors, a study of a PV/Thermal UTC with PV cells mounted directly on the absorber was carried out.
In the first part of this project, a TRNSYS model was developed to predict the performance of a PV/Thermal UTC. It was based on an actual UTC model, but modifications were made to account for the wind, the presence of PV cells and the corrugated shape of the plate. Simulations showed that mounting the cells only on the top surfaces of the corrugations prevented the cells from being shaded by the collector and consequently, presented the greatest potential. With this configuration, it was found that the addition of PV cells on the UTC decreased the thermal energy savings by 5.9 %, but that 13.6 % of the thermal energy savings could be recovered in the production of electricity.
In the second part of the study, a prototype of a PV/Thermal UTC was constructed and tested outdoors. It was found that 10 % more electricity was obtained when the fan was turned on than for zero flow conditions. It was also observed that at greater air suction rates, more cooling of the panel was achieved and potentially higher electrical power could be produced. The effect of the PV cells on the collector thermal performance could not be quantified, however, due to the small portion of PV cells on the whole collector area.
TRNSYS simulations were performed using the prototype parameters and the weather data of some experimental days. The results predicted by the component developed showed similar trends as the experimental results. The predictions were, however, not within the experimental uncertainties. The deviation in the results was attributed to the fact that the wind heat losses were not estimated accurately by the model and the non-uniform suction at the panel surface that prevented the prototype tested to work at its optimal performance.
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Tidssynkroniserade mätningar i vattenkraftstationer / Time synchronized measurements in hydropower stationsLarsson, Bertil January 2010 (has links)
Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP. The network includes the concerned hydropower stations and thus can wiring from the surface be avoided. The maximum error for the server in the specific hydroelectric power station is bounded within [-4.62, 3.18] ms relative to UTC. The conclusion is that Vattenfalls NTP-network meets the requirements to distribute time. A platform from National Instruments, programmed with the graphical language LabVIEW, has been used for data acquisition. The platform is programmed to synchronize its internal clock to a NTP-server, timestamp the input signals and save the data on the internal hard drive.
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Analytical and Experimental Study of a PV/Thermal Transpired CollectorVeronique, Delisle January 2008 (has links)
In the last few years, unglazed transpired solar collectors (UTCs) have proven to be an effective and viable method of reducing HVAC loads and building energy consumption. With the growing interest in PV/Thermal collectors, a study of a PV/Thermal UTC with PV cells mounted directly on the absorber was carried out.
In the first part of this project, a TRNSYS model was developed to predict the performance of a PV/Thermal UTC. It was based on an actual UTC model, but modifications were made to account for the wind, the presence of PV cells and the corrugated shape of the plate. Simulations showed that mounting the cells only on the top surfaces of the corrugations prevented the cells from being shaded by the collector and consequently, presented the greatest potential. With this configuration, it was found that the addition of PV cells on the UTC decreased the thermal energy savings by 5.9 %, but that 13.6 % of the thermal energy savings could be recovered in the production of electricity.
In the second part of the study, a prototype of a PV/Thermal UTC was constructed and tested outdoors. It was found that 10 % more electricity was obtained when the fan was turned on than for zero flow conditions. It was also observed that at greater air suction rates, more cooling of the panel was achieved and potentially higher electrical power could be produced. The effect of the PV cells on the collector thermal performance could not be quantified, however, due to the small portion of PV cells on the whole collector area.
TRNSYS simulations were performed using the prototype parameters and the weather data of some experimental days. The results predicted by the component developed showed similar trends as the experimental results. The predictions were, however, not within the experimental uncertainties. The deviation in the results was attributed to the fact that the wind heat losses were not estimated accurately by the model and the non-uniform suction at the panel surface that prevented the prototype tested to work at its optimal performance.
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Numerical Simulation of GaAsSb/InP Uni-Traveling Carrier PhotodiodeShrestha, Yuba R. 13 July 2005 (has links)
No description available.
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A NEW CLASS OF PRECISION UTC AND FREQUENCY REFERENCE USING IS-95 CDMA BASE STATION TRANSMISSIONSPenrod, Bruce M. 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / A new class of precision timing and frequency reference is introduced that indirectly receives
GPS timing and frequency information via TIA/EIA Standard IS-95 Code Division Multiple Access
(CDMA) mobile telecommunications base station transmissions. Like cell phones, these
products operate indoors without external antennas and provide accuracy, low cost and ease of
installation. The technology fits particularly well in IP network synchronization and quality-of-service
monitoring applications where rooftop antenna installation is often impossible. The salient
characteristics of the IS-95 CDMA signals that make them suitable for this purpose and a
general CDMA timing receiver architecture are described. Performance data versus similar references
that use conventional GPS reception are also presented.
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Simulaciones Electromagnéticas Computacionales de Fotodiodos Utc-TwRobledo Leiva, Juan Pablo Salvador January 2011 (has links)
No autorizada por el autor a ser publicada a texto completo / El objetivo de la presente memoria es simular el comportamiento electromagnético del fotomezclador UTC-TW como es parte de un proyecto de desarrollo del laboratorio de Fotónica-THz del Departamento de Ingeniería Eléctrica.
La memoria comienza con una revisión de conceptos básicos de teoría de microondas, teoría de antenas, el método de elementos finitos y las características más importantes de la estructura UTC-TW. Además se reseñan las características más importantes de dos programas para la simulación de estructuras a altas frecuencias con el método de elementos finitos: HFSS y CST MicroWave Studio.
Luego, se indica la forma en que fueron parametrizadas las dimensiones del dispositivo en los softwares HFSS y CST, las características del equipo computacional utilizado y la forma en que se analiza el dispositivo. Con esto se obtienen los primeros resultados y se los presenta.
A continuación se muestran los pasos seguidos para obtener un modelo con bajo costo computacional de la estructura para el análisis en frecuencia en el software HFSS. Se encuentra que es imposible obtener resultados útiles en HFSS debido a limitaciones de memoria RAM, lo que obliga a migrar el diseño a CST donde se realiza un análisis en el dominio del tiempo o transitorio. En CST se obtienen resultados convincentes a un menor costo en memoria y tiempo de computación, los que se comparan con resultados de un diseño simplificado en HFSS.
Finalmente se hace una comparación entre HFSS y CST MWS y se concluye que CST es la mejor alternativa para el tipo de estructura estudiada dada la situación actual del equipo computacional disponible. Además se proponen alternativas al método de elementos finitos para la simulación del dispositivo y se indican algunas consideraciones para simulaciones futuras en HFSS y CST.
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潛銷行為研究--以台灣地區藥局UTC產品為例 / The research of niche marketing-- a practical study of the UTC products of pharmacy channel in Taiwan黃勝利, Huang, Sheng Li Unknown Date (has links)
台灣製藥生技產業,長期面臨市場規模太小,全民健保藥價調降,以及國際大廠的競爭壓力。本研究以供應商對藥局零售商(B to B)的角度深入探討製藥生技產業外在環境及供應商內部條件,分析藥局潛銷行為與相關文獻理論關係,並以現代化藥局中佔營業額比例最高的嬰幼兒營養品市場為例,分析藥局潛銷行為特性及市場運作模式。
本研究歸納出潛銷行為的八項特性,分別為特有性、客製化商品、通路導向、人員銷售、高毛利率、長期關係、市場規模小、商品流動管理。這八項特性符合文獻中行銷組合(4Ps)、STP、關係行銷、競爭行為等相關理論根據。
本研究提出台灣製藥生技產業的W型雙微笑曲線模型,作為產業發展的方向,建議避開新藥研發及代工生產等高風險及低附加價值的曲線底部,以曲隔及利基發展品牌,以及與通路結合。台灣藥局潛銷行為符合中小型供應商作為發展利基及區隔市場的重要策略方向。經由產業環境分析,保健食品及化妝品是台灣醫藥生技產業目前最大也是未來最具潛力的次產業。
本研究結論顯示,最佳的藥局潛銷模式,必須符合行銷組合(4Ps)、PUSH & PULL策略、品牌策略、顧客關係管理及研發創新五大項策略組合,配合改善潛銷基本結構、流貨競價及網路銷售,以及市場競爭問題。本研究也發現,成功的潛銷行為最後會產生『策略轉換點』而面臨挑戰,潛銷行為應該要維持一定規模的市場,以保持區隔及利基的優勢。
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TIME SYNCHRONIZATION IN FLIGHT TEST DATA ANALYSISVon Zuben, Francis S. G., David, Alfred S., Jr. 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / A recurring problem in flight testing navigation systems is the need for an accurate, common time reference for the system under test and for the truth source to which it is compared. Lockheed Martin Aeronautics Company and Computer Sciences Corporation have developed software that utilizes all available timing information to reference the times of validity for each navigation measurement to Coordinated Universal Time. This permits accurate comparison and correlation of data necessary for statistical error analysis of the navigation system.
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