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McIntosh, Cecilia A. "Structure and Function of Flavonoid Glucosyltransferases: Using a Specific Grapefruit Enzyme as a Model." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/355.
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Glucosyltransferases (GTs) are enzymes that enable transfer of glucose from an activated donor (UDP-glucose) to the acceptor substrates. A flavonol specific glucosyltransferase cloned from Citrus paradisi has strict substrate and regiospecificity (Cp3OGT). The amino acid sequence of Cp3OGT was aligned with a purported anthocyanin GT from Clitorea ternatea and a GT from Vitis vinifera that can glucosylate both flavonols and anthocyanidins. Using homology modeling to identify candidate regions followed by site directed mutagenesis, three double mutations of Cp3OGT were made. Biochemical analysis of the three mutant proteins was performed. S20G+T21S protein retained activity similar to the wildtype (WT- Kmapp-80 µM; Vmax = 16.5 pkat/µg, Mutant- Kmapp-83 µM; Vmax -11 pkat/µg) but the mutant was more thermostable compared to the WT and this mutation broadened its substrate acceptance to include the flavanone, naringenin. S290C+S319A mutant protein retained 40% activity relative to wildtype, had an optimum pH shift, but had no change in substrate specificity (Kmapp-18 µM; Vmax-0.5 pkat/µg). H154Y+Q87I protein was inactive with every class of flavonoid tested. Product identification revealed that the S20G+T21S mutant protein widened the substrate and regio-specificity of CP3OGT. Docking analysis revealed that H154 and Q87 could be involved in orienting the ligand molecules within the acceptor binding site. H363, S20, and S150 were also found to make close contact with the 7-OH, 4-OH and 3’-OH groups, respectively.
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McIntosh, Cecilia A. "Structure and Function of Flavonoid Glucosyltransferases: Using a specific Grapefruit Enzyme as a Model." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/369.
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Luo, Hongwei, and Hongwei luo@rmit edu au. "Modelling and simulation of large-scale complex networks." RMIT University. Mathematical and Geospatial Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080506.142224.
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Real-world large-scale complex networks such as the Internet, social networks and biological networks have increasingly attracted the interest of researchers from many areas. Accurate modelling of the statistical regularities of these large-scale networks is critical to understand their global evolving structures and local dynamical patterns. Traditionally, the Erdos and Renyi random graph model has helped the investigation of various homogeneous networks. During the past decade, a special computational methodology has emerged to study complex networks, the outcome of which is identified by two models: the Watts and Strogatz small-world model and the Barabasi-Albert scale-free model. At the core of the complex network modelling process is the extraction of characteristics of real-world networks. I have developed computer simulation algorithms for study of the properties of current theoretical models as well as for the measurement of two real-world complex networks, which lead to the isolation of three complex network modelling essentials. The main contribution of the thesis is the introduction and study of a new General Two-Stage growth model (GTS Model), which aims to describe and analyze many common-featured real-world complex networks. The tools we use to create the model and later perform many measurements on it consist of computer simulations, numerical analysis and mathematical derivations. In particular, two major cases of this GTS model have been studied. One is named the U-P model, which employs a new functional form of the network growth rule: a linear combination of preferential attachment and uniform attachment. The degree distribution of the model is first studied by computer simulation, while the exact solution is also obtained analytically. Two other important properties of complex networks: the characteristic path length and the clustering coefficient are also extensively investigated, obtaining either analytically derived solutions or numerical results by computer simulations. Furthermore, I demonstrate that the hub-hub interaction behaves in effect as the link between a network's topology and resilience property. The other is called the Hybrid model, which incorporates two stages of growth and studies the transition behaviour between the Erdos and Renyi random graph model and the Barabasi-Albert scale-free model. The Hybrid model is measured by extensive numerical simulations focusing on its degree distribution, characteristic path length and clustering coefficient. Although either of the two cases serves as a new approach to modelling real-world large-scale complex networks, perhaps more importantly, the general two-stage model provides a new theoretical framework for complex network modelling, which can be extended in many ways besides the two studied in this thesis.
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Bachman, William Hendricks. "Towards a GIS-based modal model of automobile exhaust emissions." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21762.
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Santos, Pedro Miguel Matos dos. "Investment in new HUB for Oil & Gas Engineering Centres by Oil & Gas Services Companies." Master's thesis, Instituto Superior de Economia e Gestão, 2014. http://hdl.handle.net/10400.5/7882.
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Mestrado em FinançasO renovado interesse na indústria petrolífera coloca-a no topo da lista de prioridades de investimento estrangeiro para alguns países. A competitividade empresarial é um factor bastante importante numa Sociedade global e, como tal, um factor que não pode ser descurado a este nível. O objectivo deste trabalho assenta no estudo de uma decisão de investimento referente à possível expansão da actividade de empresas prestadoras de serviços na indústria petrolífera. Além da definição do enunciado da situação, uma resolução é apresentada. Esta resolução assenta em três metodologias distintas: - Modelo Free Cash-Flow; - Análise Strengths, Weaknesses, Opportunities e Threats (SWOT); - Modelo Matriz Híbrida. O modelo de Free Cash-Flow permitiu considerar os custos de capital de cada empresa e chegar a uma conclusão sobre o país/local que apresenta as métricas financeiras mais apelativas. A análise SWOT oferece-nos uma visão mais generalista acerca dos países considerados sobre a perspectiva de investimento.. Com o intuito de analisar factores estratégicos induzidos por parâmetros externos (de forma a não considerar apenas métricas financeiras), foi criada uma Matriz Híbrida e foi realizada a respectiva análise. Neste seguimento, os resultados apresentados pelo Modelo de Matriz Híbrida deverão ser considerados aquando da decisão de expansão. Foi possível concluir que a melhor opção base é a criação de um escritório em Portugal. Apesar desta conclusão, a solução óptima é observada quando contabilizamos os custos de abrir um escritório em Portugal e quando, simultaneamente, consideramos os impostos que são pagos na Holanda (devido à sua política de impostos mais atractiva).
The renewed interest in the Oil & Gas sector places this Industry at the top of the list of priorities for some countries in order to attract foreign investment. Corporate competitiveness is, therefore, an extremely important vehicle for a globalized Society. The aim of the present work was to study the possible investment contemplated by an expansion decision taken by some Oil & Gas Services companies. Besides the definition of the problem, an adequate resolution is also presented. This resolution is sustained by three distinct methodologies: - Free Cash-Flow Model; - Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis; - Hybrid Matrix Model. The Free Cash-Flow Model enabled us to consider costs of capital and come to a decision regarding the country that presented the best financial results. The SWOT analysis provided a more generalist view over the several analysed countries. With the purpose of analysing strategic factors induced by external parameters (besides the financial field), the Hybrid Matrix Model was created and a study was carried out. Subsequently, the results presented by the Hybrid Matrix Model shall be taken into account when choosing a location for an international expansion. It was possible to conclude that the best base scenario is observed when opening an Office in Portugal. However, the optimal solution would be opening an Office in Portugal and account the profits/losses in the Netherlands, mixing the country that presents the lowest costs with the country that has the best taxation policies.
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HURD, JOHN K. JR. "A GIS MODEL TO ESTIMATE SNOW DEPTH USING DIFFERENTIAL GPS AND HIGH-RESOLUTION DIGITAL ELEVATION DATA." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1177640172.
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Veronez, Maurício Roberto. "Proposta de um modelo regional para a redução do efeito sistemático da ionosfera através do método seqüencial de ajustamento." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-28092015-095816/.
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O posicionamento de pontos, com o sistema GPS, tornou-se uma ferramenta importante, aplicável nas mais diferentes áreas do conhecimento. No entanto, em algumas situações, a exigência de elevadas precisões trouxe a inconveniência de um custo elevado na aquisição de receptores de dupla freqüência. Mesmo com os avanços tecnológicos, a ionosfera é uma das fontes de erro que mais afetam o posicionamento de pontos. Para os usuários que possuem equipamentos de dupla freqüência, este erro é modelado com grande eficiência através do processamento de dados com solução iono free. No Brasil, a maioria dos usuários possui equipamentos que captam informações apenas do código C/A e/ou código C/A e portadora L1. Neste caso faz-se uso de alguns modelos, como, por exemplo, o de Klobuchar, com redução do erro nos posicionamentos absolutos de, aproximadamente, 50%. Nos posicionamentos relativos, com bases superiores a 20 Km, a utilização deste modelo não é a mais indicada. Neste contexto, este trabalho consiste no desenvolvimento de um método que possibilite modelar o atraso ionosférico através de um polinômio do segundo grau, baseado no ajustamento seqüencial de observações. As informações necessárias para esta modelagem são advindas das estações GPS da Rede Brasileira de Monitoramento Contínuo. Isto possibilita, em posicionamentos absolutos, determinar o atraso ionosférico de uma forma mais eficiente que o obtido pelo modelo de Klobuchar. Em posicionamentos relativos, para os usuários de equipamentos de simples freqüência, tal modelagem permite a geração de um código com características semelhantes ao código P2. Assim, com os dados gerados por receptores de uma freqüência, é possível processar vetores de bases longas por meio da solução iono free code. Os resultados obtidos indicam que tal metodologia pode ser uma alternativa eficiente para minimizar o efeito ionosférico no posicionamento de pontos com o sistema GPS. Horizontalmente, através dos métodos de posicionamento Single Point e relativo, respectivamente, o modelo ionosférico proposto proporcionou uma melhoria de 39% e 26% se comparado com o modelo de Klobuchar.Point positioning, with GPS, became an important tool applicable to the most different areas of the knowledge. However, in some situations, the requirement of high precisions brought the inconvenience of a high cost in the acquisition of dual receivers frequency. Despite of the technological advances, the ionosphere is one of the error sources that affect most point positioning. For users who have dual equipment frequency, this error is modeled with great efficiency through data processing with the ionosphere free solution. In Brazil the majority of the users has equipments that process C/A code information only and/or C/A code and L1 carrier. In this case it is necessary to use some models, for example the Klobuchar model, with error reduction of approximately 50% in absolute point positioning. In the relative positioning, with baselines longer than 20 Km, the use of this model is not indicated. Thus, this work consists in developing a method that makes possible to model the ionospheric delay using a second degree polynomial, based on sequential adjustment of observations. The necessary information for this modeling is obtained from GPS stations that compose the RBMC (Brazilian Network for Continuous Monitoring of GPS). Thus it is possible to determine the ionospheric delay in a more efficient way in absolute positioning than when using the Klobuchar model. In relative positioning, for single frequency users, such modeling allows the generation of a code, with similar characteristics to the P2 code. Hence, with data generated by single frequencies, it is possible to process long base line vectors, using the iono free code solution. The results obtained indicate that such methodology can be an efficient alternative to minimize the ionospheric effect in the GPS point positioning. Horizontally, through the methods of positioning Single Point and relative, respectively, the ionospheric model considered provided an improvement of 39% and 26% if compared with the Klobuchar model.
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Clark, Alexandra Lynn, and Alexandra Lynn Clark. "A groundwater flow model of Indian Wells Valley, California, Utilizing GMS with GIS applications." Thesis, The University of Arizona, 1999. http://hdl.handle.net/10150/626875.
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The sustainability of a potable groundwater supply in the regional aquifer of
Indian Wells Valley, California, is threatened by overdraft and by induction of
contaminated upper aquifer waters into the lower, regional aquifer. A three layer
MODFLOW groundwater model is developed in GMS (Groundwater Modeling System)
to enhance understanding of the hydro logic flow regime and to serve as a groundwater
management tool. The steady-state model is calibrated with water level measurements
collected during 1920 and 1921. Water level data spanning several decades are used in
transient model calibration. Calibration is by trial and error adjustment of the
transmissivity with subsequent recharge refinement. Model simulated heads agree with
observed heads in most regions within ten feet, except for the southwest, which may
require additional field investigation. The model suggests that less than 5000 acre
feet/year of recharge may supply the valley, compared with previous model estimates of
9840 acre-feet/year.
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Bandreddy, Naga Abhiram. "Defining Correlation Between Radon, Uranium Deposits, and Oil and Gas Wells Using GIS Regression Methods." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1564687565423414.
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Yongqian, Wang, Li Xianliang, and Zhang Qishan. "A Vehicle Tracking System Based on GPS." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/611591.
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International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, NevadaVehicle tracking system based on GPS has been paid more and more attention. The system consists of GIS (Geological Information System), master station, movable station and communication network. Movable stations installed on automobiles transmit their position and status messages to the master station. All vehicles' tracks are drawn on the electrical map displayed by the master station's computer screen in real time. Vehicles' alarming signals can also be transmitted to the master station simultaneously. This paper presents a whole designing scheme of the vehicle tracking system, then it makes a thorough introduction to the system's performance and working procedure. The key technologies employed by the system and the relations between them are also discussed in details in the paper.
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Arimboor, Chinnan Jacob. "Simulation and validation of in-cylinder combustion for a heavy-duty Otto gas engine using 3D-CFD technique." Thesis, KTH, Förbränningsmotorteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-245172.
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Utsläpp från bilar har spelat stor roll de senaste decennierna. Detta har lett till ökad användning av Otto gasmotorer som använder naturgas som bränsle. Nya motordesigner behöver optimeras för att förbättra motorens effektivitet. Ett effektivt sätt att göra detta på är genom användningen av simuleringar för att minska ledtiden i motorutvecklingen. Verifiering och validering av simuleringarna spelar stor roll för att bygga förtroende för och förutsägbarhet hos simuleringsresultaten. Syftet med detta examensarbete är att föreslå förbränningsmodellparametrarna efter utvärdering av olika kombinationer av förbrännings- och tändmodeller för Otto förbränning, vad gäller beräkningstid och noggrannhet. In-cylindertrycksspår från simulering och mätning jämförs för att hitta den bästa kombinationen av förbrännings- och tändmodell. Inverkan av tändtid, antal motorcykler och randvillkor för simuleringsresultatet studeras också. Resultaten visar att ECFM-förbränningsmodellen förutsäger simuleringsresultaten mer exakt när man jämför med mätningarna. Effekten av tändningstiden på olika kombinationer av förbrännings- och tändningsmodell utvärderas också. Stabiliteten hos olika förbränningssimuleringsmodeller diskuteras också under körning för fler motorcykler. Jämförelse av beräkningstid görs även för olika kombinationer av förbrännings- och tändmodeller. Resultaten visar också att flamspårningsmetoden med Euler är mer känslig för cellstorlek och kvalitet hos simuleringsnätet, jämfört med övriga studerade modeller. Rekommendationer och förslag ges om nät- och simulerings-inställningar för att prediktera förbränningen på ett så bra sätt som möjligt. Några möjliga förbättringsområden ges som framtida arbete för att förbättra noggrannheten i simuleringsresultaten.Emission from automobiles has been gaining importance for past few decades. This has gained a lot of impetus in search for alternate fuels among the automotive manufacturers. This led to the increase usage of Otto gas engine which uses natural gas as fuel. New engine designs have to be optimized for improving the engine efficiency. This led to usage of virtual simulations for reducing the lead time in the engine development. The verification and validation of actual phenomenon in the virtual simulations with respect to the physical measurements was quite important. The aim of this master thesis is to suggest the combustion model parameters after evaluating various combination of combustion and ignition models in terms of computational time and accuracy. In-cylinder pressure trace from the simulation is compared with the measurement in order to find the nest suited combination of combustion and ignition models. The influence of ignition timing, number of engine cycles and boundary conditions on the simulation results are also studied. Results showed that ECFM combustion model predicts the simulation results more accurately when compare to the measurements. Impact of ignition timing on various combination of combustion and ignition model is also assessed. Stability of various combustion simulation models is also discussed while running for more engine cycles. Comparison of computational time is also made for various combination of combustion and ignition models. Results also showed that the flame tracking method using Euler is dependent on the mesh resolution and the mesh quality. Recommendations and suggestions are given about the mesh and simulation settings for predicting the combustion simulation accurately. Some possible areas of improvement are given as future work for improving the accuracy of the simulation results.
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Araya, Yeheyies. "Detecting Swiching Points and Mode of Transport from GPS Tracks." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-91320.
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In recent years, various researches are under progress to enhance the quality of the travel survey. These researches were mainly performed with the aid of GPS technology. Initially the researches were mainly focused on the vehicle travel mode due to the availability of GPS technology in vehicle. But, nowadays due to the accessible of GPS devices for personal uses, researchers have diverted their focus on personal mobility in all travel modes. This master’s thesis aimed at developing a mechanism to extract one type of travel survey information particularly travel mode from collected GPS dataset. The available GPS dataset is collected for travel modes of walk, bike, car, and public transport travel modes such as bus, train and subway. The developed procedure consists of two stages where the first is the dividing the track trips into trips and further the trips into segments by means of a segmentation process. The segmentation process is based on an assumption that a traveler switches from one transportation mode to the other. Thus, the trips are divided into walking and non walking segments. The second phase comprises a procedure to develop a classification model to infer the separated segments with travel modes of walk, bike, bus, car, train and subway. In order to develop the classification model, a supervised classification method has been used where decision tree algorithm is adopted. The highest obtained prediction accuracy of the classification system is walk travel mode with 75.86%. In addition, the travel modes of bike and bus have shown the lowest prediction accuracy. Moreover, the developed system has showed remarkable results that could be used as baseline for further similar researches.
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Forrest, Timothy Lee. "Logistic regression models for predicting trip reporting accuracy in GPS-enhanced household travel surveys." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/4667.
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This thesis presents a methodology for conducting logistic regression modeling of trip and household information obtained from household travel surveys and vehicle trip information obtained from global positioning systems (GPS) to better understand the trip underreporting that occurs. The methodology presented here builds on previous research by adding additional variables to the logistic regression model that might be significant in contributing to underreporting, specifically, trip purpose. Understanding the trip purpose is crucial in transportation planning because many of the transportation models used today are based on the number of trips in a given area by the purpose of a trip. The methodology used here was applied to two study areas in Texas, Laredo and Tyler-Longview. In these two study areas, household travel survey data and GPS-based vehicle tracking data was collected over a 24-hour period for 254 households and 388 vehicles. From these 254 households, a total of 2,795 trips were made, averaging 11.0 trips per household. By comparing the trips reported in the household travel survey with those recorded by the GPS unit, trips not reported in the household travel survey were identified. Logistic regression was shown to be effective in determining which household- and trip-related variables significantly contributed to the likelihood of a trip being reported. Although different variables were identified as significant in each of the models tested, one variable was found to be significant in all of them - trip purpose. It was also found that the household residence type and the use of household vehicles for commercial purposes did not significantly affect reporting rates in any of the models tested. The results shown here support the need for modeling trips by trip purpose, but also indicate that, from urban area to urban area, there are different factors contributing to the level of underreporting that occurs. An analysis of additional significant variables in each urban area found combinations that yielded trip reporting rates of 0%. Similar to the results of Zmud and Wolf (2003), trip duration and the number of vehicles available were also found to be significant in a full model encompassing both study areas.
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Robidoux, Jeff. "Real-Time Spatial Monitoring of Vehicle Vibration Data as a Model for TeleGeoMonitoring Systems." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/32426.
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This research presents the development and proof of concept of a TeleGeoMonitoring (TGM) system for spatially monitoring and analyzing, in real-time, data derived from vehicle-mounted sensors. In response to the concern for vibration related injuries experienced by equipment operators in surface mining and construction operations, the prototype TGM system focuses on spatially monitoring vehicle vibration in real-time. The TGM vibration system consists of 3 components: (1) Data Acquisition Component, (2) Data Transfer Component, and (3) Data Analysis Component. A GPS receiver, laptop PC, data acquisition hardware, triaxial accelerometer, and client software make up the Data Acquisition Component. The Data Transfer Component consists of a wireless data network and a data server. The Data Analysis Component provides tools to the end user for spatially monitoring and analyzing vehicle vibration data in real-time via the web or GIS workstations. Functionality of the prototype TGM system was successfully demonstrated in both lab and field tests. The TGM vibration system presented in this research demonstrates the potential for TGM systems as a tool for research and management projects, which aim to spatially monitor and analyze data derived from mobile sensors in real-time.Master of Science
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Sharma, Nishchay. "Knock Model Evaluation – Gas Engine." Thesis, KTH, Maskinkonstruktion (Avd.), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-237133.
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Knocking is a type of abnormal combustion which depends on several physical factors and results in high frequency pressure oscillations inside the combustion chamber of a spark-ignited internal combustion engine (ICE). These oscillations can damage the engine and hamper its efficiency, which is why it is important for automakers to understand the knocking behavior so that it can be avoided during engine operation. Due to the catastrophic outcomes of knocking a lot of research has been done in the past on prediction of its occurrence. There can be several causes of knocking but when it occurs due to auto-ignition of fuel in the end-gas it’s called spark-knock. There are various mathematical models that predict the phenomenon of spark-knock. In this thesis, several of the previously published knock prediction models for heavy-duty natural-gas engine are studied and analyzed. The main objective of this project is to assess the accuracy of different types of knock prediction models.Amongst all the types of knock prediction models emphasize has been given to empirical correlation models, particularly to the ones which are based on chemical kinetics pertaining to the combustion process of methane. These are the models that claim to predict ignition delay time based on concentration of air and fuel in the unburned zone of the cylinder. The models are assessed based on the knocking behavior they represent across the engine operation range. Results pertaining to the knock prediction models are evaluated in a 1D engine simulation model using AVL BOOST. The BOOST performance prediction model is calibrated against experimentally measured engine test-cell data and the same data is used to assess the knock prediction models.The knock prediction model whose results correlate with experimental observations is analyzed further while other models are discarded. Using the validated model, variation in knock occurrence is evaluated with change in the combustion phasing. Two of the parameter that are used to define the combustion phasing are spark-advance and combustion duration. It was found that when the brake mean effective pressure is kept constant the knock prediction parameter increases linearly with increase in spark advance and decreases linearly with increase in combustion duration. The variation of knock prediction parameter with spark advance showed increasing gradient with increase in engine torque.Knack i en förbränningsmotor är en typ av onormal förbränning. Det är ett komplicerat fenomen som beror på flera fysiska faktorer och resulterar i högfrekventa tryckoscillationer inuti förbränningskammaren. Dessa oscillationer kan skada motorn och fenomenet hämmar motorns effektivitet. Knack kan uppstå på två sätt i en Otto-motor och detta examensarbete kommer att handla om självantändning. Självantändning, i detta fall, är när ändgasen börjar brinna utan att ha blivit påverkad av flamfronten eller gnistan från tändstiftet. Det finns flera olika matematiska modeller som i olika grader kan prediktera knackfenomenet. I detta examensarbete studeras några av de tidigare publicerade prediktionsmodellerna för knack i Otto-förbränning och modelleras för analys. Huvudsyftet med detta projekt är således att bedöma noggrannheten hos olika typer av knackmodeller. Extra fokus har lagts på empiriska korrelationsmodeller, särskilt till de som är baserade på kemisk kinetik avseende förbränningsprocessen av metan. Dessa modeller förutsäger den tid det tar för ändgasen att självantända, baserat på dess koncentration av luft och bränsle. Knackmodellerna bedöms sedan utifrån det beteende som de förutsäger över motorns driftområde och dess överensstämmelse med kända motorkalibreringsstrategier. Resultatet av knackpredikteringen för de olika knackmodellerna utvärderas och valideras i en motorsimuleringsmodell i mjukvaran AVL BOOST. BOOST-modellen kalibreras mot experimentellt uppmätta motortestdata. Baserat på resultaten från de valda knockmodellerna så blev den modell som bäst korrelerar med kända motorkalibreringsstrategier analyserad djupare. Den utvalda modellen var en ECM modell och den utvärderas ytterligare med avseende på variation i predikterad knack-parameter. Detta görs genom att modifiera två förbränningsparametrar: tändvinkel och förbränningsduration. Det visade sig att modellerna predikterade en linjär ökning då tändningen tidigareläggs och ett linjärt minskande vid längre förbränningsduration, vilket är i enlighet med motortestdata. Vidare visade det sig att variationer i tändvinkel resulterade i en högre gradient i knackpredikteringen vid högre motorbelastningar och korresponderande minskning vid lägre belastning.
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Oliveira, Alarcon Matos de. "Mapeamento de áreas suscetíveis a inundação por rompimento de barragem em ambiente semiárido." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-09032017-114124/.
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Barragens pode ser considerando como risco potencial, o conhecimento da forma provável que se comportaria uma onda de cheia (escoamento crítico), provocado pelo rompimento de barragem é muito importante para as populações que residem à jusante do barramento, como acontece em São José do Jacuípe. Isto por que em caso de rompimento torna-se necessário existir plano de evacuação para área afetada a jusante. Neste sentido destaca-se a utilização de modelos ambientais aliados ao SIG como eficaz ferramenta que possibilita mapear áreas com susceptibilidade a inundação em caso de rompimento. O HEC-RAS surge como poderoso modelo hidrológico capaz de efetuar o modelo para rompimento de barragem em integração com o Sistema de Informação Geográfica. E para classificar o grau de risco da população a jusante é fundamental a adoção de metodologia que contemple as variáveis inerentes à importância deste empreendimento, por tanto será utilizado à metodologia de Menescal (2001) por abarcar todas as facetas importantes de segurança de barragem.Dams can be considering as a potential risk, knowledge of probable way to behave a flood wave (critical flow) caused by dam break is very important for people living on the bus downstream, as in São José do Jacuípe. This is because in case of breakage becomes necessary to have the evacuation plan for the downstream affected area. In this sense there is the use of environmental models combined with GIS as an effective tool that makes it possible to map areas with susceptibility to flooding in the event of disruption. The HEC-RAS comes as powerful hydrological model able to make the model for dam breaking in integration with Geographic Information System. And to classify the degree of risk of downstream population is essential to adopt methodology that considers the variables inherent importance of this project for both will be used to Menescal methodology (2001) to cover all the important facets of dam safety.
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Ribeiro, Marcelle Dorneles. "Tecnologia GPS em pesquisa de origem e destino." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/101182.
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As pesquisas de origem e destino (Pesquisas O/D) são tradicionalmente realizadas a partir do relato dos participantes de todas as viagens ocorridas nos últimos dias. No entanto, uma série de estudos realizados recentemente aponta que existem equívocos nos relatos dos participantes nas pesquisas O/D tradicionais, principalmente em relação à distância e ao tempo dos percursos relatados. Esses estudos apontam a utilização da tecnologia GPS (Global Positioning System) como uma forma confiável para a obtenção de informações sobre cada etapa de viagem. A tecnologia GPS, apesar de suas limitações, está disponível popularmente nos últimos anos e apresenta resultados significativos de registros em tempo real, inclusive de viagens curtas. Dessa forma, foram levantadas as experiências internacionais de estudos de pesquisas O/D segmentadas por etapa de viagem, utilizando a tecnologia GPS. Com base nisso, foi aplicada uma pesquisa de origem e destino na Região Metropolitana de Porto Alegre com GPS e com Entrevistas posteriores. Os estudos estrangeiros apontam que essa é a melhor forma para obtenção dos dados e minimização dos erros. Os dados coletados na pesquisa O/D foram tabulados em um banco de dados e as informações registradas foram tratadas em softwares gráficos gratuítos. Sendo assim, foi possível cruzar os dados relatados pelos participantes na entrevista com os dados registrados pelo aparelho GPS. As análises apontam que todos os indivíduos apresentaram discrepâncias no relato da duração e da distância, em comparação aos dados efetivamente registrados. Essas discrepâncias foram tanto positivas quanto negativas. As implicações dessas diferenças entre os dados relatados e registrados no GPS para fins de modelagem foram vistas nos modelos de escolha modal Logit Multinomial elaborados. O modelo elaborado a partir de dados registrados pelo GPS aponta ajustes apropriados e resultado significativo de variáveis. O modelo elaborado com base nos dados relatados não se comporta como o esperado, conforme as hipóteses previamente estabelecidas, e apresenta variáveis não significativas.Origin and destination surveys are traditionally made from the participants' reports of all trips occurring in the last days, known as Diary Trip. However, a number of recent studies show that there are mistakes in the accounts of participants in traditional origin and destinations surveys, especially in relation to distance and time. These studies point the use of GPS (Global Positioning System) technology as a reliable way to obtain information about each trip leg. GPS technology, despite its limitations, is popularly available in recent years and presents significant results of real-time records, including short trips. Therefore, we surveyed the experiences of international origin and destination studies segmented by leg trip, using GPS technology. Based on this, a origin and destination survey was applied in the metropolitan region of Porto Alegre with GPS and Diary Trip. Foreign studies indicate that this is the best way to obtain the data and minimizing errors. The data collected in the origin and destination survey were tabulated in a database and the information recorded was treated in free graphics software. Therefore, it was possible to cross the data reported by the participants in the Diary Trips with the data recorded by the GPS. The analyzes suggest that all subjects had discrepancies in reporting the duration and distance, compared to the data actually reported. These discrepancies have been both positive and negative. The implications of these differences, between reported and recorded on the GPS data, for modeling, can be seeing in the modal choice model Multinomial Logit elaborate. The model developed from data recorded by the GPS indicates appropriate adjustments and significant outcome variables. The model developed based on reported data does not behave as expected, as previously established hypotheses, and presents no significant variables.
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Jin, Kang Meir Amnon J. "The lattice gas model and Lattice Boltzmann model on hexagonal grids." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/master's/JIN_KANG_53.pdf.
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EDWARDS, KARLA ROBERTA LISA. "Site-Specific Point Positioning and GPS Code Multipath Parameterization and Prediction." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1300860715.
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Dufresne, Michel 1962. "Fluid model of dielectric barrier gas discharge." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34520.
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A two-fluid model of dielectric barrier gas discharge is presented in this thesis. The model predicts the physical structure of the gas discharge obtained between two electrodes, when one is covered with a dielectric material: It predicts the distribution of the electron and ion particle densities, electron energy, and electric field strength. It is a self-consistent numerical model, in which the dielectric properties of the dielectric material are included and the geometry of the electrodes is taken into account, thus coupling the charged-particle transport to the electric field.New boundary conditions are developed for the electron gas at the anode; the results indicate that the common boundary conditions frequently used in the literature give solutions with non-physical behavior. The new boundary conditions give solutions with the expected physical behavior.
The equations of the model are formulated numerically using a Galerkin finite element method and solved using the Newton iteration method. New universal matrices for the finite element method are presented which can be used to construct complex finite element matrices, by replacing integrals with matrix products, in a consistent and uniform manner independent of element shape, dimensionality, and order.
Solutions for DC, pulse-waveform and time-harmonic applied electrode voltages for geometries with and without a dielectric barrier are presented. The regulating effect of the dielectric barrier by surface charge accumulation is shown for discharge under constant applied voltage, assuming a static temperature for the electron gas, for the full self-consistent model. Also, simulations of dielectric barrier discharge with applied pulse-waveform voltages are compared with simulations of applied time-harmonic voltages. The results show very similar period-averaged electric fields, electron temperature profiles, charged particle densities, and total conduction current densities. However, a much higher period-integrated ionization rate is obtained from voltage pulse simulations, compared to time-harmonic voltage simulations. Therefore, we obtain a greater reaction rate for an equivalent conduction current, in a period-averaged sense, for a discharge driven by pulse-waveform applied voltages than with time-harmonic applied voltages. Such a difference was not observed for simulations without the dielectric barrier.
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Dufresne, Michel. "Fluid model of dielectric barrier gas discharge." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36971.pdf.
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Tagner, Nikita, and Arian Abedin. "Thermodynamic model for power generating gas turbines." Thesis, KTH, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170917.
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Gasturbiner används i en mängd olika sammanhang, från kraftgenerering till flygplansmotorer. Prestandan hos gasturbiner beror på omgivningstillstånd såsom temperatur och tryck. Gasturbintillverkare förser ofta vissa parametrar, exempelvis uteffekt och massflöde i avgaserna vid väldefinierade standard tillstånd, ofta refererade till som ISO-tillstånd. På grund av det tidigare beskrivna beroendet är det nödvändigt för köpare att kunna förutspå prestandan vid platsen där gasturbinen ska användas. I denna studie har en termodynamisk modell för kraftgenerande gasturbiner konstruerats. Modellen förutspår uteffekten vid full belastning för varierande omgivningstemperatur och omgivningstryck. Den konstruerade modellen har jämförts med prestandadata från Siemens egna modeller, vid varieande temperatur. Prestandadata för varierande tryck kunde inte erhållas. Den konstruerade modellen är konsekvent med Siemens modeller inom vissa temperaturintervall vars längd beror på den utvärderade gasturbinens storlek. För mindre gasturbiner är temperaturintervallet för vilken den konstruerade modellen är konsekvent längre än för större gasturbiner.Gas turbines are used for a variety of purposes ranging from power generation to aircraft engines. Their performance is dependent on ambient conditions such as temperature and pressure. Gas turbine manufacturers often provide certain parameters like power output and exhaust mass flow at well-defined standard conditions, usually referred to as ISO-conditions. Due to the aforementioned dependency, it is necessary for buyers to be able to predict gas turbine performance at their chosen site of operation. In this study, a thermodynamic model for power generating gas turbines has been constructed. It predicts the power output at full load for varying ambient temperature and pressure. The constructed model has been compared with performance data taken from Siemens own models for varying temperatures. No performance data for varying pressures could be obtained. The constructed model is consistent with the Siemens models within certain temperature intervals, which differ depending on the size of the gas turbine. For smaller gas turbines, the interval where the constructed model is consistent is greater than for larger gas turbines.
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董鵬飛 and Pang-fei Tung. "IntelliMap: a new GIS model with intelligence." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221804.
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Tung, Pang-fei. "IntelliMap : a new GIS model with intelligence /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20793273.
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Jin, Qinghua. "GASMAK2 model for longwall gob gas emission." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2706.
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Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains x, 93 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 71-72).
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Caserta, Alice Jordam. "Desenvolvimento de relações não-lineares para mecanismos de contato por meio de estudo analítico e numérico." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-17112015-134233/.
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Fenômenos multifásicos são frequentemente observados na natureza, tais como nas gotas de chuva ou neve no ar, nos vulcões e tempestades de areia, e em diversas outras situações. Na solução desses problemas que envolvem escoamentos gás-sólidos e granulares são frequentemente utilizadas duas abordagens: a contínua (formulação Euleriana-Euleriana) e a discreta (formulação Euleriana-Lagrangiana). Na abordagem discreta pode-se utilizar dois modelos para descrever o contato entre as partículas: o modelo de esfera rígida e o modelo de esfera suave. Neste trabalho é realizado um estudo detalhado dos modelos de contato, com foco na modelagem de esfera suave, que é baseada em um sistema dinâmico mola-massa-amortecedor. Por meio desse estudo, com a finalidade de aprimorar o modelo de contato não-linear, são propostas duas relações para o mecanismo de contato de partículas. Essas relações são fundamentadas em um modelo dinâmico, com não-linearidades nas partes conservativas e dissipativas, não apresentando descontinuidades entre as acelerações do início e do fim do contato. A metodologia de desenvolvimento da presente pesquisa está dividida em três partes: pesquisa bibliográfica dos modelos de contato; estudo analítico e numérico desses modelos e testes de problemas com a realização de experimentos numéricos, utilizando o código computacional MFIX (Multiphase Flow with Interphase eXchange). As novas aproximações propostas neste trabalho são analisadas e aplicadas em três diferentes problemas: de dinâmica, escoamento gás-sólido e escoamento granular. Os resultados obtidos utilizando as relações são comparados com dados disponíveis na literatura, mostrando-se adequados para os casos investigados neste trabalho.Multiphase flow are frequently observed in nature, such as rain drops in air or snowfalls, volcanoes and sandstorms, and several other situations. For solving these problems which involve gas-solid and granular flows are often used two models: the continuous model (Eulerian-Eulerian formulation) and the discrete model (Eulerian-Lagrangian formulation). There are two main contact models used in DEM, the hard-sphere model and the soft-sphere model. In this work is carried out a detailed study of contact models, focusing on soft-sphere model, based on a dynamic system modeled as nonlinear mass-spring-damper. In order to improve the nonlinear contact model, in this study it is proposed two new approximate relations for determining the damping coefficient and duration of contact for a specific nonlinear soft-sphere contact model where the contact force is continuous at the start and end of the contact. The methodology of the development of this work is divided into three parts: literature research of the contact models; analytical and numerical study of these models and test problems with numerical experiments, using the open source code MFIX (Multiphase Flow with Interphase eXchange). The proposed relations are analyzed and applied in three different problems: dynamic problem, gas-solid flow and granular flow. All results are compared with literature data showing good agreement for these cases studied in the present work.
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Murthy, J. N. "Gas turbine combustor modelling for design." Thesis, Cranfield University, 1988. http://hdl.handle.net/1826/2626.
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The design and development of gas turbine combustors is a crucial but uncertain part of an engine development process. Combustion within a gas turbine is a complex interaction of, among other things, fluid dynamics, heat and mass transfer and chemical kinetics. At present, the design process relies upon a wealth of experimental data and correlations. The proper use of this information requires experienced combustion engineers and even for them the design process is very time consuming.
Some major engine manufacturers have attempted to address the above problem by developing one dimensional computer programs based on the above test and empirical data to assist combustor designers. Such programs are usually proprietary. The present work, based on this approach has yielded DEPTH, a combustor design program. DEPTH ( Design and Evaluation of Pressure, Temperature and Heat transfer in combustors) is developed in Fortran-77 to assist in preliminary design and evaluation of conventional gas turbine combustion chambers.
DEPTH can be used to carry out a preliminary design along with prediction of the cooling slots for a given metal temperature limit or to evaluate heat transfer and temperatures for an existing combustion chamber. Analysis of performance parameters such as efficiency, stability and NOx based on stirred reactor theories is also coupled. DEPTH is made sufficiently interactive/user-friendly such that no prior expertise is required as far as computer operation is concerned. The range of variables such as operating conditions, geometry, hardware, fuel type can all be effectively examined and their contribution towards the combustor performance studied. Such comprehensive study should provide ample opportunity for the designer to make the right decisions. It should also be an effective study aid. Returns in terms of higher thermal efficiencies is an incentive to go for combined cycles and cogeneration. In such cases, opting for higher cycle pressures together with a second or reheat combustor promise higher thermal efficiencies and exhaust temperatures and hence such designs are likely to be of interest. The concepts that are needed for understanding a double or reheat combustor are also addressed using the programme. A specific application of the programme is demonstrated through the design of a double combustor.
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Chung, Gi Yun. "An analytical approach to real-time linearization of a gas turbine engine model." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50702.
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A recent development in the design of control system for a jet engine is to use a suitable, fast and accurate model running on board. Development of linear models is particularly important as most engine control designs are based on linear control theory. Engine control performance can be significantly improved by increasing the accuracy of the developed model. Current state-of-the-art is to use piecewise linear models at selected equilibrium conditions for the development of set point controllers, followed by scheduling of resulting controller gains as a function of one or more of the system states. However, arriving at an effective gain scheduler that can accommodate fast transients covering a wide range of operating points can become quite complex and involved, thus resulting in a sacrifice on controller performance for its simplicity.
This thesis presents a methodology for developing a control oriented analytical linear model of a jet engine at both equilibrium and off-equilibrium conditions. This scheme requires a nonlinear engine model to run onboard in real time. The off-equilibrium analytical linear model provides improved accuracy and flexibility over the commonly used piecewise linear models developed using numerical perturbations. Linear coefficients are obtained by evaluating, at current conditions, analytical expressions which result from differentiation of simplified nonlinear expressions. Residualization of the fast dynamics states are utilized since the fast dynamics are typically outside of the primary control bandwidth. Analytical expressions based on the physics of the aerothermodynamic processes of a gas turbine engine facilitate a systematic approach to the analysis and synthesis of model based controllers. In addition, the use of analytical expressions reduces the computational effort, enabling linearization in real time at both equilibrium and off-equilibrium conditions for a more accurate capture of system dynamics during aggressive transient maneuvers.
The methodology is formulated and applied to a separate flow twin-spool turbofan engine model in the Numerical Propulsion System Simulation (NPSS) platform. The fidelity of linear model is examined by validating against a detailed nonlinear engine model using time domain response, the normalized additive uncertainty and the nu-gap metric. The effects of each simplifying assumptions, which are crucial to the linear model development, on the fidelity of the linear model are analyzed in detail. A case study is performed to investigate the case when the current state (including both slow and fast states) of the system is not readily available from the nonlinear simulation model. Also, a simple model based control is used to illustrate benefits of using the proposed modeling approach.
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Charnock, Thomas W. "GIS linked environmental process models." Thesis, Aston University, 1997. http://publications.aston.ac.uk/13272/.
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In recent years there has been a great effort to combine the technologies and techniques of GIS and process models. This project examines the issues of linking a standard current generation 2½d GIS with several existing model codes. The focus for the project has been the Shropshire Groundwater Scheme, which is being developed to augment flow in the River Severn during drought periods by pumping water from the Shropshire Aquifer. Previous authors have demonstrated that under certain circumstances pumping could reduce the soil moisture available for crops. This project follows earlier work at Aston in which the effects of drawdown were delineated and quantified through the development of a software package that implemented a technique which brought together the significant spatially varying parameters. This technique is repeated here, but using a standard GIS called GRASS. The GIS proved adequate for the task and the added functionality provided by the general purpose GIS - the data capture, manipulation and visualisation facilities - were of great benefit. The bulk of the project is concerned with examining the issues of the linkage of GIS and environmental process models. To this end a groundwater model (Modflow) and a soil moisture model (SWMS2D) were linked to the GIS and a crop model was implemented within the GIS. A loose-linked approach was adopted and secondary and surrogate data were used wherever possible. The implications of which relate to; justification of a loose-linked versus a closely integrated approach; how, technically, to achieve the linkage; how to reconcile the different data models used by the GIS and the process models; control of the movement of data between models of environmental subsystems, to model the total system; the advantages and disadvantages of using a current generation GIS as a medium for linking environmental process models; generation of input data, including the use of geostatistic, stochastic simulation, remote sensing, regression equations and mapped data; issues of accuracy, uncertainty and simply providing adequate data for the complex models; how such a modelling system fits into an organisational framework.
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Jensen, Anne-Lise B. "Models of gas-liquid solubilities." Thesis, Aston University, 1996. http://publications.aston.ac.uk/9616/.
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A recent method for phase equilibria, the AGAPE method, has been used to predict activity coefficients and excess Gibbs energy for binary mixtures with good accuracy. The theory, based on a generalised London potential (GLP), accounts for intermolecular attractive forces. Unlike existing prediction methods, for example UNIFAC, the AGAPE method uses only information derived from accessible experimental data and molecular information for pure components. Presently, the AGAPE method has some limitations, namely that the mixtures must consist of small, non-polar compounds with no hydrogen bonding, at low moderate pressures and at conditions below the critical conditions of the components. Distinction between vapour-liquid equilibria and gas-liquid solubility is rather arbitrary and it seems reasonable to extend these ideas to solubility. The AGAPE model uses a molecular lattice-based mixing rule. By judicious use of computer programs a methodology was created to examine a body of experimental gas-liquid solubility data for gases such as carbon dioxide, propane, n-butane or sulphur hexafluoride which all have critical temperatures a little above 298 K dissolved in benzene, cyclo-hexane and methanol. Within this methodology the value of the GLP as an ab initio combining rule for such solutes in very dilute solutions in a variety of liquids has been tested. Using the GLP as a mixing rule involves the computation of rotationally averaged interactions between the constituent atoms, and new calculations have had to be made to discover the magnitude of the unlike pair interactions. These numbers have been seen as significant in their own right in the context of the behaviour of infinitely-dilute solutions. A method for extending this treatment to "permanent" gases has also been developed. The findings from the GLP method and from the more general AGAPE approach have been examined in the context of other models for gas-liquid solubility, both "classical" and contemporary, in particular those derived from equations-of-state methods and from reference solvent methods.
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Miles, Luke G. "Global Digital Elevation Model Accuracy Assessment in the Himalaya, Nepal." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1313.
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Digital Elevation Models (DEMs) are digital representations of surface topography or terrain. Collection of DEM data can be done directly through surveying and taking ground control point (GCP) data in the field or indirectly with remote sensing using a variety of techniques. The accuracies of DEM data can be problematic, especially in rugged terrain or when differing data acquisition techniques are combined. For the present study, ground data were taken in various protected areas in the mountainous regions of Nepal. Elevation, slope, and aspect were measured at nearly 2000 locations. These ground data were imported into a Geographic Information System (GIS) and compared to DEMs created by NASA researchers using two data sources: the Shuttle Radar Topography Mission (STRM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Slope and aspect were generated within a GIS and compared to the GCP ground reference data to evaluate the accuracy of the satellitederived DEMs, and to determine the utility of elevation and derived slope and aspect for research such as vegetation analysis and erosion management. The SRTM and ASTER DEMs each have benefits and drawbacks for various uses in environmental research, but generally the SRTM system was superior. Future research should focus on refining these methods to increase error discrimination.
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Strömgren, Tobias. "Model predictions of turbulent gas-particle shear flows." Doctoral thesis, KTH, Mekanik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12135.
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A turbulent two-phase flow model using kinetic theory of granularflows for the particle phase is developed and implmented in afinite element code. The model can be used for engineeringapplications. However, in this thesis it is used to investigateturbulent gas-particle flows through numerical simulations. The feedback from the particles on the turbulence and the meanflow of the gas in a vertical channel flow is studied. In particular,the influence of the particle response time, particle volumefraction and particle diameter on the preferential concentration ofthe particles near the walls, caused by the turbophoretic effect isexplored. The study shows that when particle feedback is includedthe accumulation of particles near the walls decreases. It is also foundthat even at low volume fractions particles can have a significant impacton the turbulence and the mean flow of the gas. The effect of particles on a developing turbulent vertical upward pipeflow is also studied. The development length is found to substantiallyincrease compared to an unladen flow. To understand what governs thedevelopment length a simple estimation was derived, showing that itincreases with decreasing particle diameters in accordance with themodel simulations. A model for the fluctuating particle velocity in turbulentgas-particle flow is derived using a set of stochastic differentialequations taking into account particle-particle collisions. Themodel shows that the particle fluctuating velocity increases whenparticle-particle collisions become more important and that increasingparticle response times reduces the fluctuating velocity. The modelcan also be used for an expansion of the deterministic model for theparticle kinetic energy.QC20100726
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Fang, Yi. "An urban traffic network model using GIS technology." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/845978.
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This creative project was proposed to develop a GIS model for transportation planning purposes with the ARC/INFO software. The urban street network in the GIS model was based on urban arterial systems in the city of Muncie, Indiana. The model was also expected to demonstrate the applicability of GIS technology in transportation planning. Several transportation planning techniques were tested with the model which included road and traffic data inventory, optimum pathing, road capacity analysis, traffic shift study modeling, and graphic presentation. The case study was targeted on road capacity analysis of urban arterial network as well as study of alternative traffic route for the urban route of State Road 32 in Muncie. The project began with an discussion of GIS technology, GIS application in planning, and ARC/INFO software programs. Then an urban street information model was developed in form of digital network in the computer database which could perform the functions of data inventory, spatial traffic analysis, and mapping manipulation. Finally the case studies were performed to demonstrate the application of this GIS network model. The findings and analysis results generated by GIS operation were used to evaluate the traffic conditions as well as to determine the feasibility of alternative route for State Road tables, ARC/INFO macro programs, traffic maps, and print-out of analysis results.Department of Urban Planning
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Al-Kindi, F. J. "A model for impulse breakdown of SF6̲." Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382317.
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Chamorro, Alexander. "The analysis of pipeline leak tests using DEGADIS model." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=913.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains ix, 123 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 64-65).
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Liao, Chaqing. "Gas ejector modeling for design and analysis." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3206.
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Shi, Jianjun. "Experimental and theoretical studies of atmospheric glow discharges." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/7982.
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This thesis presents the experimental and theoretical studies of nonthermal and stable atmospheric-pressure glow discharges. With the excitation frequency in the kilohertz range, a uniform and stable glow discharge has been successfully produced in atmospheric helium without the usually indispensable dielectric barrier. For this barrier-free cold atmospheric discharge, there are two discharge events occurring, respectively, in the voltage-rising and the voltage-falling phases, and in general they compete with each other. This distinct feature is illustrated through a detailed fluid simulation. For direct current atmospheric glow discharges, their cathode fall region is shown to depend critically on the discharge current density. For atmospheric glow discharges excited at 13.56 MHz on the other hand, we present observations that after gas breakdown, the discharge evolves from the normal glow mode to the abnormal glow mode and then through the recovery mode back to the normal glow mode. The operation modes, namely the a mode and the y mode, in radio-frequency atmospheric glow discharges are investigated with a one-dimensional, self-consistent continuum model. This model is evaluated by comparing our numerical results with experimental data and other simulation results in literature. It is shown that gas ionization is volumetric in the a mode and localized in the boundary region between the sheath and the bulk plasma in the y mode. The stable operation regime in the a mode is found to have a positive differential conductivity, and can be expanded to higher discharge current density without compensating plasma reactivity by increasing the excitation frequency. Furthermore this plasma stability-reactivity balance is also studied for radio-frequency atmospheric glow microdischarges.
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Marques, Artur Pantoja. "Proposta de um programa de gestão de qualidade para uma empresa genérica de posicionamentos com GPS." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-10022009-124605/.
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Este trabalho trata da proposta de um Sistema de Gestão da Qualidade para uma empresa genérica prestadora de serviços de posicionamento com o GPS, como alternativa para melhorar a gestão da organização e garantir a qualidade de seus serviços e produtos. O aumento da demanda por esse tipo de serviço estimulou o aparecimento de novas empresas específicas em GPS e adaptação de antigas para atender um mercado crescente e cada vez mais exigente. Por se tratar de um processo novo, sua implantação requer mudanças significativas tanto de ordem técnica (intimamente ligadas ao conhecimento específico do sistema e suas capacidades) como administrativa (meios e políticas que possam garantir uma gestão efetiva de todos os processos envolvidos no posicionamento com o GPS dentro da empresa). A modernização imposta ao setor de topografia e geodésia em seu cenário produtivo e econômico, com o aparecimento de novas técnicas produtivas e ferramentas gerenciais, não pode mais ser protelada. Isso impõe às organizações uma necessidade emergencial de mudança e grandes desafios, entre eles o de sua própria sobrevivência. A execução de um serviço de posicionamento com o sistema GPS consiste em uma seqüência de procedimentos práticos que, se forem bem executados, proporcionarão maior probabilidade de êxito ao resultado final. Os procedimentos dependem muito de cada caso, e normalmente são definidos por indicações dos fabricantes dos instrumentos, normas e especificações oficiais e, na grande maioria das vezes, pela própria experiência prática do responsável. Como parte desse trabalho foi desenvolvida uma pesquisa social para identificar como são e como agem as empresas que prestam serviços de posicionamento com o sistema GPS no Brasil. Com base nos resultados dessa pesquisa, elaborou-se uma empresa genérica de posicionamento com GPS, com características similares à maioria, e que serviu como referência na concepção dos padrões para os processos básicos da empresa. O modelo de gestão da qualidade proposto teve como guia o Sistema da Qualidade preconizado pela ISO série 9000. Consideraram-se também as ferramentas de gestão e controle da qualidade comumente aplicados na indústria de manufatura e adaptados aos serviços de um posicionamento com GPS. O resultado apresenta uma seqüência de implantação do modelo com as devidas recomendações e viabilidades. Para ilustrar, são apresentados os resultados benéficos obtidos com a aplicação direta dos padrões técnicos da empresa genérica, em um posicionamento real para pontos estáticos, em que se considerou apenas a parte produtiva. O resultado mostrou-se bastante convincente.This thesis deals with a proposal for quality management for a generic GPS surveying company as an alternative to management and service quality improvement. As a result of the GPS measurement demand increasing, an important number of new companies and/or renovated ones have been established in order to operate in that market. But considering that it is a new process some changes must be performed in order to accommodate the old surveying techniques and the old fashioned management to the new reality. This implies in a new management organization which must be based on a well described procedure sequence aiming a final quality control success. As an important part of that research a social research has been applied to several Brazilian GPS service provider companies with the purpose of knowing the status of the sector related to the quality management. Based on that research a hypothetical company was considered in order to give subsides to the elaboration of a standardized company. The proposed quality management model was based on the ISO 9000 Quality System adopting management tools and quality control operators applied in the general industry adapted to the GPS surveying companies. This thesis shows the results of that research presenting an implementation model for quality management considering a real surveying GPS work based on the new GPS measurement techniques.
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Nandakumar, Neha. "Computational models of natural gas markets for gas-fired generators." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/108213.
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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 69-72).
Climate change is a major factor reforming the world's energy landscape today, and as electricity consumes 40% of total energy, huge efforts are being undertaken to reduce the carbon footprint within the electricity sector. The electric sector has been taking steps to reform the grid, retiring carbon-intensive coal plants, increasing renewable penetration, and introducing cyber elements end-to-end for monitoring, estimating, and controlling devices, systems, and markets. Due to retirements of coal plants, discovery of shale gas leading to low natural gas prices, and geopolitical motives to reduce dependence on foreign oil, natural gas is becoming a major fuel source for electricity around the United States. In addition, with increasingly intermittent renewable sources in the grid, there is a need for a readily available, clean, and flexible back-up fuel; natural gas is sought after in New England to serve this purpose as a reliable and guaranteed fuel in times when wind turbines and solar panels cannot produce. While research has been conducted advocating natural gas pipeline expansion projects to ensure this reliability, not enough attention has been paid to the overall market structure in the natural gas and electricity infrastructures which can also impact reliable delivery of gas and therefore efficient interdependency between the two infrastructures. This thesis explores the market structures in natural gas and electricity, the interdependence of natural gas and electricity prices with increasing reliance on natural gas as the penetration of renewable energy resources (RER) increases in order to complement their intermittencies, possible volatilities in these prices with varying penetration rates in RER, and alternatives to existing market structures that improve reliability and reduce volatility in electricity and gas prices. In particular, the thesis will attempt to answer the following two questions: What will the generation mix look like in 2030 and how will this impact gas and electricity prices? How do Gas-Fired Generator (GFG) bids for gas change between 2015 and 2030? In order to answer these questions, a computational model is determined using regression analysis tools and an auction model. Data from the New England region in terms of prices, generation, and demand is used to determine these models.
by Neha Nandakumar.
S.M. in Technology and Policy
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Izgec, Bulent. "Performance analysis of compositional and modified black-oil models for rich gas condensate reservoirs with vertical and horizontal wells." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/237.
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It has been known that volatile oil and gas condensate reservoirs cannot be modeled accurately with conventional black-oil models. One variation to the black-oil approach is the modified black-oil (MBO) model that allows the use of a simple, and less expensive computational algorithm than a fully compositional model that can result in significant timesaving in full field studies. The MBO model was tested against the fully compositional model and performances of both models were compared using various production and injection scenarios for a rich gas condensate reservoir. The software used to perform the compositional and MBO runs were Eclipse 300 and Eclipse 100 versions 2002A. The effects of black-oil PVT table generation methods, uniform composition and compositional gradient with depth, initialization methods, location of the completions, production and injection rates, kv/kh ratios on the performance of the MBO model were investigated. Vertical wells and horizontal wells with different drain hole lengths were used. Contrary to the common belief that oil-gas ratio versus depth initialization gives better representation of original fluids in place, initializations with saturation pressure versus depth gave closer original fluids in place considering the true initial fluids in place are given by the fully compositional model initialized with compositional gradient. Compared to the compositional model, results showed that initially there was a discrepancy in saturation pressures with depth in the MBO model whether it was initialized with solution gas-oil ratio (GOR) and oil-gas ratio (OGR) or dew point pressure versus depth tables. In the MBO model this discrepancy resulted in earlier condensation and lower oil production rates than compositional model at the beginning of the simulation. Unrealistic vaporization in the MBO model was encountered in both natural depletion and cycling cases. Oil saturation profiles illustrated the differences in condensate saturation distribution for the near wellbore area and the entire reservoir even though the production performance of the models was in good agreement. The MBO model representation of compositional phenomena for a gas condensate reservoir proved to be successful in the following cases: full pressure maintenance, reduced vertical communication, vertical well with upper completions, and producer set as a horizontal well.
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Dejan, Jovanov. "Model optimizacije monitoringa deponijskog gasa i procedne vode na zatvorenim deponijama." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2016. http://www.cris.uns.ac.rs/record.jsf?recordId=101593&source=NDLTD&language=en.
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U okviru disertacije, korišćenjem linearnog programiranja, definisanisu različiti modeli za optimizaciju monitoringa deponijskog gasa iprocedne vode na zatvorenim deponijama. Razvoj modela je baziranna grafičkoj metodi linearnog programiranja i upotrebi softveraGeoGebra. Na osnovu dobijenih rezultata, identifikovani su parametrimonitoringa procedne vode kao i obim monitoringa deponijskog gasai procedne vode. Evaluirani su ekonomski i legislativni efektimodelovanja i uočene značajne mogućnosti uštede i unapređenjaprocesa monitoring zatvorenih deponija.This doctoral dissertation, by using the linear programming, has definedthe various optimization models for the monitoring of landfill gas andleachate at the closed landfills. The development of the model is basedon graphical method of linear programming and the usage of GeoGebrasoftware. According to the results, leachate monitoring parameters andlandfill gas and leachate monitoring volume have been identified. Theeconomical and legislative effects of the models have also beenevaluated, as well as the considerate possibilities for financial savingand improvement of the closed landfill monitoring process.
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Xiaobo, Xie, Zhang Qishan, and Huang Xingjian. "EMBEDDED GIS IN INTELLIGENT NAVIGATION SYSTEM." International Foundation for Telemetering, 2002. http://hdl.handle.net/10150/607542.
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International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, CaliforniaEmbedded GIS in Intelligent Navigation System is a special information system. This paper puts forward several basic principles and constraints during design for Embedded GIS at first, and then analyzes the feature of embedded platform and the function of Intelligent Navigation System, and presents a realization scheme of Embedded GIS.
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Walid, Hanna Motaz. "Aanvändning av lantmäteriets nya nationella höjdmodell (laserdata) i skogsmark." Thesis, Högskolan Väst, Avdelningen för data-, elektro- och lantmäteriteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-10352.
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Detta arbete redogör för hur användning av den nya nationella höjdmodellen (NNH) ur/i Lantmäteriet databas kan användas i olika terräng och vilka förutsättningar det finns för identifiering av specifika landskapselement i denna, manuellt och visuellt. Sedan 2009 har Lantmäteriet laserskannat hela landet, både på land och över vatten. Uppdraget är slutfört 2015. Målet med laserskanning är att framställa en rikstäckande höjdmodell med ett medelfel som är bättre än 0.5 m. Idag är all NNH-data tillgänglig som LAS-filer på Lantmäteriets databas. För att kunna utföra ett utvärderingsexperiment valdes ett geografiskt begränsat område: I Skepplanda, Ale kommun i Västra Götalands län. De hjälpmedel som användes var GPS-mottagare, LAS-filer, Ortofoto och applikationsprogram såsom OL-laser och ArcGis. Det främsta syftet med studien var att undersöka hur bearbetning och utvärdering av olika kartmaterial kan utföras, för att sedan kunna bedöma i vilken mån användning av Lantmäteriets NNH-data, i olika typer av terräng, kan vara möjlig t.ex. hur små detaljer kan urskiljas i det. För undersökningen valdes specifika objekt, såsom stenmurar och ett dike. Tre olika kartunderlag framtogs av OL-laserprogrammet: lutningsbilder, intensitetsbilder och terrängskuggningsbilder. Utifrån insamling av inmätta punkter och med hjälp av vektordata kunde materialet utvärderas visuellt. Två kartor valdes, vilka uppfyllde kriterierna för att kunna uppnå studiens syfte. Eftersom kartan med terrängskuggning och lutningsbild ger en tydligare profil av områdets karaktäristiska drag på marknivå, är det möjligt att identifiera små markdetaljer såsom stenmurar och diken. Resultatet varierade från fall till fall, beroende på kartunderlaget. En mur på den ena platsen i en bild kunde t.ex. detekteras, men inte i en annan bild, trots att det finns en mur där. Studien visade att laserpulserna har svårt att tränga igenom tät vegetation, dock kan olika solvinklar och belysningsriktningar ändå framhäva vissa små markdetaljer under en tätskog. Andra faktorer som kan ha påverkat kvalitén på lasermaterialet är flyghöjden, laserskannerns vinkel och under vilken period under året skanningen genomfördes. Ett antagande gjordes, att laserskanning från lägre flyghöjd och mindre öppningsvinkel kan höja kvalitén på laserdata. Med dessa två faktorer kan högre upplösning per kvadratmeter yta uppnås. Ett annat sätt som kan vara aktuellt i en undersökning är att använda OL-laser verktygslåda och tillämpa andra inställningar genom att skapa objekthöjdbilder där höjd färgläggs med olika ekvidansnivå. Genom att prova fram olika inställningar i programmet, där olika lutningshöjd och solvinklar tillämpas kan läsbarheten på kartunderlaget förbättras.This work describes how the use of the new national elevation model (NNH) from the National Land Survey database may be used in a variety of terrain and the conditions they are identification of specific landscape elements, manually and visually. From the start of 2009, the national land Survey laserscannat whole country, both on land and over water. The mission will be completed in 2015. The goal of laser scanning is to produce a nationwide elevation model with a standard error of better than 0.5 m for a 2 m GRID. Today, all NNH data available as LAS files on Lantmäteriet's database. To perform an evaluation experiment was elected a geographically limited area: Skepplanda, Ale Municipality in Västra Götaland. The devices used were GPS receiver, LAS files, Orth imagery and application programs such as OL laser and ArcGIS. The main aim of the study was to investigate the processing and evaluation of different map material can be performed, and then to assess to what extent the use of Lantmäteriets NNH- data in different types of terrain may be possible. For the investigation, the specific items, such as stone walls and a ditch. Three different maps material was developed by the OL laser program: slope images, intensity images and terrain shading images. Based on the collection of measured points and using vector data could material evaluated visually. Two maps were chosen, which met the criteria for being able to achieve the objectives of the study. Since the map with terrain shading and gradient image provides a clearer profile of the area's characteristic features at ground level, it is possible to identify small land features such as stone walls and ditches. Results will vary from case to case, depending on the substrate maps. A wall at one location in an image could e.g. detect, but not in another image, even though it's a wall there. That’s why definitive conclusions could be not established. The study showed that the laser pulses are difficult to penetrate dense vegetation; however different solar angles and lighting directions nonetheless highlight some small land details during a dense forest. Other factor that may have affected the quality of the laser material is the altitude, laser scans angle and during which period of the year the scan was performed. An assumption was made that the laser scans from lower altitude and smaller opening angle can add value to laser data. With these two factors, higher resolution per square meter of surface is achieved. Another way that can be relevant in an investigation is to use the OL laser toolbox and apply different settings to create objects height pictures where height is colored with different evidence level. By trying out different settings in the program, where different slope height and solar angles applied to the readability of the chart surface is improved.
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Pritchard, Alison Clare. "Gas-dynamical models for astrophysical jets." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291024.
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Alemu, Aklilu W. "Modelling greenhouse gas emissions in cattle: From rumen to the whole-farm." Elsevier B.V. (Animal Feed Science and Technology), 2011. http://hdl.handle.net/1993/14668.
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Mathematical modeling in animal agriculture can be applied at various levels including at the tissue, organ, animal, farm, regional and global levels. The purposes of this research were i) to evaluate models used to estimate volatile fatty acid (VFA) and methane (CH4) production and assess their impact on regional enteric CH4 inventory, and ii) to develop a process-based, whole-farm model to estimate net farm GHG emissions. In the first study, four VFA stoichiometric models were evaluated for their prediction accuracy of rumen VFA and enteric CH4 production. Comparison of measured and model predicted values demonstrated that predictive capacity of the VFA models varied with respect to the type of VFA in rumen fluid which impacted estimated enteric CH4 production. Moving to a larger scale assessment, we examined the enteric CH4 inventory from Manitoba beef cattle (from 1990 to 2008) using two mechanistic rumen models that incorporate VFA stoichiometric models: COWPOLL and MOLLY, and two empirical models: Intergovernmental Panel on Climate Change (IPCC) Tier 2 and a nonlinear equation (Ellis). The estimated absolute enteric CH4 production varied among models (7 to 63%) indicating that estimates of GHG inventory depend on model selection. This is an important consideration if the values are to be used for management and/or policy-related decisions. Development of models at the individual farm component level (animal, soil, crop) does not accurately reflect net GHG emissions generated from the whole production system. We developed a process-based, whole-farm model (Integrated Components Model, ICM), using the existing farm component models COWPOLL, manure-DNDC and some aspects of IPCC to integrate farm components and their associated GHG emissions. Estimates of total farm GHG emissions and their relative contribution using the ICM were comparable to estimates using two other whole-farm models (Integrated Farm System Model and Holos model). Variation was observed among models both in estimating whole-farm GHG emissions and the relative contribution of the different sources in the production system. Overall, whole-farm models are required to explore management options that will mitigate GHG emissions and promote best management practices. However, for full assessment of the production system, other benefits of the system (e.g., carbon sequestration, ecosystem services), which are not part of current whole-farm models, must be considered.
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Moyano, Jiménez Florentí. "Un model d'empresa energètica local: "gas reusense" (1854-1969)." Doctoral thesis, Universitat Rovira i Virgili, 2009. http://hdl.handle.net/10803/8626.
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Gas Reusense és un model d'indústria energètica, formada per una majoria de capital local, que serveix com a referència per a l'anàlisi d'altres indústries creades el segle XIX, en ciutats espanyoles de dimensions similars. L'objectiu principal de l'empresa de Reus va ser la producció i subministrament de gas, primer destinat a l'enllumenat públic i poc després al consum particular. L'empresa reusenca, com va succeir en altres llocs de Catalunya i Espanya, també va introduir l'electricitat a la ciutat de Reus, l'any 1898, i els gasos derivats del petroli, l'any 1960. Amb el cas de Gas Reusense, es mostra l'evolució tecnològica del sector del gas, el desenvolupament de l'oferta i la demanda energètica i el procés de modernització què per a la societat va significar el gas i l'electricitat. De la mà del gas, la població de les ciutats va fer la transició cap a la contemporaneïtat energètica.
Gas Reusense is a model of energetic industry, formed by the majority of the local capital, which serves as a reference for the analysis of the other industries created in the 19th century, in Spanish cities of similar dimensions. The principal objective of the company from Reus was the production and provision of the gas, first destined for the street lighting and soon after to the private consumption.
As it happened in other places of Catalonia and Spain, this company also brought electricity to the city of Reus, in 1898, as well as the butane gas, in 1960. The case of Gas Reusense shows the technological evolution in the gas sector, the development of the energetic supply and demand and also the process of modernization which meant for the society gas and electricity. Thanks to gas, the population of the cities made a transition towards the modern age of the energy.
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Buffington, John Charles. "A multiple-location model for natural gas forward curves." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0033/NQ46812.pdf.
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Korak, Ghosh. "Model predictive control for civil aerospace gas turbine engines." Thesis, University of Sheffield, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595827.
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Larsson, Emil. "Model Based Diagnosis and Supervision of Industrial Gas Turbines." Doctoral thesis, Linköpings universitet, Fordonssystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-106256.
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Supervision of performance in gas turbine applications is important in order to achieve: (i) reliable operations, (ii) low heat stress in components, (iii) low fuel consumption, and (iv) efficient overhaul and maintenance. To obtain good diagnosis performance it is important to have tests which are based on models with high accuracy. A main contribution of the thesis is a systematic design procedure to construct a fault detection and isolation (FDI) system which is based on complex nonlinear models.These models are preliminary used for simulation and performance evaluations. Thus, is it possible to use thesemodels also in the FDI-system and whichmodel parts are necessary to consider in the test design? To fulfill the requirement of an automated design procedure, a thermodynamic gas turbine package GTLib is developed. Using the GTLib framework, a gas turbine diagnosismodel is constructed where component deterioration is introduced. In the design of the test quantities, equations from the developed diagnosis models are carefully selected.These equations are then used to implement a Constant Gain Extended Kalman filter (CGEKF) based test quantity.The number of equations and variables which the test quantity is based on is significantly reduced compared to the original reference model.The test quantity is used in the FDI-system to supervise the performance and the turbine inlet temperature which is used in the controller. An evaluation is performed using experimental data from a gas turbine site.The case study shows that the designed FDI-system can be used when the decision about a compressor wash is taken. When the FDI-system is augmented with more test quantities it is possible to diagnose sensor and actuator faults at the same time the performance is supervised. Slow varying sensor and actuator bias faults are difficult diagnose since they appear in a similar manner as the performance deterioration, but the FDI-system has the ability to detect these faults. Finally, the proposed model based design procedure can be considered when an FDI-system of an industrial gas turbine is constructed.
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Barnes, William J. (William James). "A model of galactic dust and gas from FIRAS." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/32598.
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