Dissertations / Theses on the topic 'Company modelling'
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Kvarnerås, Mattias, and Viktor Pettersson. "PROFITABILITY MODELLING FOR CREDIT MARKET COMPANY : MODELLING AND EVALUATION OF PROFITABILITY AND CREDIT RISK FOR LARGE CONTRACTS." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171988.
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Risk and profitability are two topics that companies today have to face and deal with. There are different type of risks that either directly or indirectly affect the survival of a company.After the financial crisis in 2008, new regulations and capital requirements was establishedto better cope with future crisis, as the survival of banks and credit market companies hasa vital impact on society. The objective of this thesis has been to create a model that estimates profitability withrespect to various risks but above all credit risk. Risks that credit market companies has tocomply with has been provided by PayEx via documents or meetings. Further knowledgewithin the area of risks has been acquired by reading capital requirements and regulations.The main focus on capital requirements and regulations landed in Basel III and InternalCapital Adequacy Assessment Process (ICAAP). To initiate the project an excel document was provided electronically which laid groundfor the model that was later built in the programming language Python. The first stepin building the model was to replicate all calculations so the model gave the same outputas in the excel document. Further, functions were made to be used in a simulation to seewhich parameters affected the risk-adjusted return on capital (RAROC) the most. When allsimulations were made a visualization of the results in form of plots was created to simplifythe understanding of the results. Important dynamic parameters used in the model was the end customers choice of paymentmethod, payment methods including a fee and percentage change in contract payment. Allmentioned parameters made impact on how profitable a business case were. Conclusions from the results are that payment methods, percentage change in contractpayment and payment methods including fees all affect the profit or RAROC. A recommendationis that PayEx should try to steer customers to pay according to Set 2 or Set 7,negotiate the percentage change in contract payment or add a fee to payment method 4 ifcustomers choose to pay that way. Further explanations of the mentioned Sets can be foundin Section 4.1.2.Lönsamhet och risk är två ämnen som företag idag måste ha i åtanke och förhålla sig till. Det finns olika typer av risk som antingen direkt eller indirekt påverkar ett företags överlevnad.Efter den finansiella krisen 2008, upprättades nya regler och kapitalkrav för att bättre kunnahantera framtida kriser. Detta för att kreditmarknadsbolag och banker har en stor inverkanpå samhället om de skulle gå i konkurs. Syftet med denna avhandling har varit att skapa en modell som ska estimera lönsamhet iförhållande till olika risker, men i huvudsak kreditrisk. Risker som kreditmarknadsbolagmåste förhålla sig till har tillhandahållits av PayEx via möten eller dokument. Ytterligarekunskap om risk har förvärvats genom att läsa kapitalkrav och förordningar. Huvudfokus påkapitalkrav och förordningar landade i Basel III och Internal Capital Adequacy AssessmentProcess (ICAAP). För att påbörja projektet skickades ett exceldokument elektroniskt som sedan lade grundenför modellen som skapades i programeringsspråket Python. Första steget i modellbyggandetvar att replikera alla beräkningar som gjorts i exceldokumentet och kontrollera att modellengav samma resultat. Efter det skapades funktioner som skulle användas i simuleringen föratt se vilka parametrar som påvärkade den riskjusterade avkastningen på kapital mest. Näralla simuleringar var gjorda skapades en visualisering av resultaten i form av olika grafer.Det gjordes för att förenkla förståelsen av resultaten. Viktiga dynamiska parametrar som användes i modellen var bland andra, slutkundens valav betalmetod, betalmetod inklusive avgift samt procentuell förändring av kontraktsköp.Alla nämnda parametrar hade stor påverkan på hur lönsamt ett business case är. Slutsatser av resultaten är att betalmetod, procentuell förändring av kontraktsköp och betalmetodinklusive avgift alla påverkar lönsamheten och riskjusterad avkastning på kapital.Rekommendationer till PayEx är därför att försöka styra kunderna att betala enligt Set 2eller Set 7, förhandla om den procentuella förändringen av kontraktsköp eller att addera enavgift till betalmetod 4 om kunder väljer att betala på det sättet. Djupare förklaringar avnämnda Sets finns i Section 4.1.2.
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Shani, Najah Turki. "Multivariate analysis and survival analysis with application to company failure." Thesis, Bangor University, 1991. https://research.bangor.ac.uk/portal/en/theses/multivariate-analysis-and-survival-analysis-with-application-to-company-failure(a031bf91-13bc-4367-b4fc-e240ab54a73b).html.
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This thesis offers an explanation of the statistical modelling of corporate financial indicators in the context where the life of a company is terminated. Whilst it is natural for companies to fail or close down, an excess of failure causes a reduction in the activity of the economy as a whole. Therefore, studies on business failure identification leading to models which may provide early warnings of impending financial crisis may make some contribution to improving economic welfare. This study considers a number of bankruptcy prediction models such as multiple discriminant analysis and logit, and then introduces survival analysis as a means of modelling corporate failure. Then, with a data set of UK companies which failed, or were taken over, or were still operating when the information was collected, we provide estimates of failure probabilities as a function of survival time, and we specify the significance of financial characteristics which are covariates of survival. Three innovative statistical methods are introduced. First, a likelihood solution is provided to the problem of takeovers and mergers in order to incorporate such events into the dichotomous outcome of failure and survival. Second, we move away from the more conventional matched pairs sampling framework to one that reflects the prior probabilities of failure and construct a sample of observations which are randomly censored, using stratified sampling to reflect the structure of the group of failed companies. The third innovation concerns the specification of survival models, which relate the hazard function to the length of survival time and to a set of financial ratios as predictors. These models also provide estimates of the rate of failure and of the parameters of the survival function. The overall adequacy of these models has been assessed using residual analysis and it has been found that the Weibull regression model fitted the data better than other parametric models. The proportional hazard model also fitted the data adequately and appears to provide a promising approach to the prediction of financial distress. Finally, the empirical analysis reported in this thesis suggests that survival models have lower classification error than discriminant and logit models.
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Basiri, Mohammad Hossein. "Developments in computer modelling for the valuation of group mining companies." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326604.
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Burden, Timothy Henry Arthur. "A thesis on company modelling for integrated strategic and operational planning." Thesis, Birmingham City University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283163.
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Herculano, Miguel Colburn. "Modelling long-term worker´s compensation : an application to a general insurance company." Master's thesis, Último nome, Primeiro nome. data de publicação. "Título". Dissertação de Mestrado. Universidade de Lisboa. Instituto Superior de Economia e Gestão, 2013. http://hdl.handle.net/10400.5/6043.
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Mestrado em Ciências ActuariaisThis paper resumes the main findings from modeling life underwriting risks to which Worker´s Compensation is exposed. Models presented aim to shorten the path between ad hoc procedures in place and the new capital requirements foreseen by Solvency II. The legal framework of this line of business is primarily explained as it is determinant for modeling purposes. We then provide a discussion about risk models in use, major options, assumptions and other relevant issues that were regarded when modeling this line of business.
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Naish, Jane Catherine. "Process capability modelling for manufacturing process selection in an integrated simultaneous engineering workstation." Thesis, University of Strathclyde, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366813.
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Bergström, Sofia. "Modelling Business Capabilities withEnterprise Architecture : A Case Study at a Swedish Pension Managing Company." Thesis, KTH, Industriella informations- och styrsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175378.
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This master thesis looks at the use of business capabilities within enterprisearchitecture, and investigates how the concept is used within the Swedish pension managingcompany Folksam. Based on interviews with stakeholders an enterprise architecture metamodelcentred on the business capability is constructed. The meta-model is then edited andrevised according to a questionnaire aimed at removing irrelevant elements, and a secondset of interviews discussing a capability's health status and well being. This second set ofinterviews resulted in the removal of elements not aecting the well being of a capability.The nal meta-model has the business capability and the capability health status at itscore. It consists of the Capability element, with two attributes, surrounded by nine otherelements connected by eleven relations in total.Detta examensarbete undersoker hur verksamhetsformagor anvandsinom enterprisearkitektur, och vidare hur formage-konceptet anvands pa det svenska pensionsforetaget Folksam. Baserat pa intervjuer med intressenter skapas en metamodell medverksamhetsformagan i centrum. Metamodellen revideras och andras sedan enligt ett frageformular vars mal var att ta bort ej relevanta element, och enligt en andra omgang intervjuerdar en formagas halsa diskuteras. Denna andra omgang intervjuer resulterade i att elementsom inte paverkade formagans halsa togs bort. Den slutgiltiga metamodellen har verksamhetsformagan och dess halsostatus i fokus. Den bestar av formage-elementet, med tvaattribut, omgardat av nio andra element som binds ihop av totalt elva olika relationer.
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Watson, Iain David. "An investigation of the use of market and industry data in financial distress modelling : based on data derived from the Unlisted Securities Market and Official List." Thesis, University of Ulster, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339298.
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Al-Busaidi, Adil G. "Automatic generation control of the Petroleum Development Oman (PDO) and the Oman Electricity Transmission Company (OETC) interconnected power systems." Thesis, Teesside University, 2012. http://hdl.handle.net/10149/263268.
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Petroleum Development Oman (PDO) and Oman Electricity Transmission Company (OETC) are running the main 132kV power transmission grids in the Sultanate of Oman. In the year 2001, PDO and OETC grids were interconnected with a 132kV Over head transmission line linking Nahada 132kV substation at PDO's side to Nizwa 132kV sub-station at OETC's side. Since then the power exchange between PDO and OETC is driven by the natural impedances of the system and the frequency and power exchange is controlled by manually re-dispatching the generators. In light of the daily load profile and the forecasted Gulf Cooperation Council (GCC) states electrical interconnection, it is a great challenge for PDO and OETC grids operators to maintain the existing operation philosophy. The objective of this research is to investigate Automatic Generation Control (AGC) technology as a candidate to control the grid frequency and the power exchange between PDO and OETC grid. For this purpose, a dynamic power system model has been developed to represent PDO-OETC interconnected power system. The model has been validated using recorded data from the field which has warranted the requirement of refining the model. Novel approaches have been followed during the course of the model refining process which have reduced the modelling error to an acceptable limit. The refined model has then been used to assess the performance of different AGC control topologies. The recommended control topologies have been further improved using sophisticated control techniques like Linear Quadratic Regulator (LQR) and Fuzzy Logic (FL). Hybrid Fuzzy Logic Proportional Integral Derivative (FLPID) AGC controller has produced outstanding results. The FLPID AGC controller parameters have then been optimised using Multidimensional Unconstrained Nonlinear Minimization function (fminsearch) and Particle Swarm Optimisation (PSO) method. The PSO has been proved to be much superior to fminsearch function. The robustness of the LQR, the fminsearch optimized FLPID and the PSO FLPID optimized AGC controllers has been assessed. The LQR robustness found to be slightly better than the FLPID technique. However the FLPID supercedes the LQR due to the limited number of field feedback signals in comparison to the LQR. Finally, a qualitative assessment of the benefits of the ongoing GCC interconnection project on PDO and OETC has been done through modelling approach. The results proved that the GCC interconnection will bring considerable benefits to PDO and OETC but the interconnection capacity between PDO and OETC needs to be enhanced. However, the application of AGC on PDO and OETC will alleviate the PDO-OETC interconnection capacity enhancement imposed by the GCC interconnection.
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Almqvist, Marcus, and Charlotta Lundberg. "A Business Modelling Framework for the Front End of Innovation. : Customising a Guiding Material for an Early Phase of the Innovation Process for a Swedish Fintech Company." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263089.
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The Swedish Fintech company that is subject to this thesis has proposed a process through which all new ideas should go through before entering the development funnel, called the ‘Proof-of-Concept-process’. Today, there exists no material that helps and guides the idea owner through one of the more extensive phases of that process. The purpose of this thesis is to develop a material for this phase. The material is developed through a literature review and qualitative interviews. The topics included in the literature review are: ‘Innovation’, ‘Uncertainty’, ‘Front End of Innovation’ and ‘Business Modelling’. Semi-structured qualitative interviews were performed separately with three out of four members of the top management team. Continuous discussions with the industrial supervisor facilitated the development of the framework. The result consists of two parts, (1) the results from the interviews with the management team which aims to lay the foundation for the requirement specification on which components the framework should contain, and (2) a framework for how business modelling can be done at this phase of the innovation process. The result is a material that uses the graphical branding of the company so that it can be treated as an internal document. An unbranded version of the result is presented in this thesis. The framework is presented together with a deeper analysis of the separate building blocks that form its structure, together with suggestions on techniques that aims to help the user of the material. We argue that the result is a business modelling framework that considers recommendations for how to handle the FEI, and that regards theory on business modelling as well as interviews with managers at the subject company to establish what techniques such a framework should include. Further, the result is based on a wide variety of literature and authors. Concluding, we argue that the result can be considered a bridge between two relatively young research areas ‘Front end of Innovation’ and ‘Business Modelling’ with its primary application at one specific company.Det svenska Fintech-bolaget som behandlas i denna masteruppsats har föreslagit en process genom vilken alla nya idéer ska gå igenom innan dess genomförbarhet testas i en ’Proof-of-Concept’. Denna process är på företaget kallad ‘Proof-of-Concept-processen’. Idag finns det inget material som hjälper och guidar idéägaren genom en av de mer omfattande faserna av processen. Syftet med denna masteruppsats är att utveckla ett material för denna fas. Materialet baseras på en litteraturstudie och kvalitativa intervjuer. De ämnen som ingår i litteraturstudien är: ‘Innovation’, ‘Uncertainty’, ‘Front End of Innovation’ och ‘Business Modelling’. Kvalitativa semi-strukturerade intervjuer utfördes separat med tre av ledningens fyra medlemmar. Kontinuerlig diskussion fördes med företagshandledaren för att facilitera ramverkets utveckling. Resultatet består av två delar, (1) resultaten från intervjuerna med ledningsgruppen som syftar till att ligga till grund för kravspecifikationen på vilka komponenter materialet ska innehålla och (2) ett ramverk för hur affärsmodellering kan ske i detta stadie av innovationsprocessen. Resultatet är ett material med företagets grafiska profil för att det ska kunna bli behandlat som ett internt dokument. En version av materialet som inte har företagets grafiska språk presenteras. Ramverket presenteras tillsammans med en djupare analys av de separata byggstenar som tillsammans utgör dess struktur, samt förslag på tekniker som syftar till att hjälpa användaren av materialet att utveckla sin idé inför nästa utvärderingsmöte och möjliggöra en demokratisering av innovationsprocessen. Ramverkets struktur är ett resultat av inspiration från existerande ramverk samt intervjuerna vilket bidrar till dess anpassning till företagets specifika innovationsprocess. Vi anser att resultatet är ett ramverk för affärsmodellering som beskriver rekommendationer för hur man hanterar de tidiga faserna av innovationsprocessen. Ramverket och dess teoretiska bakgrund är baserat på ett brett utbud av litteratur och författare. Avslutningsvis hävdar vi att ramverket kan betraktas som en bro mellan två relativt unga forskningsområden ’Front End of Innovation’ och ’Business Modelling’ med sitt primära tillämpningsområde på det behandlade företaget.
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Chen, Louis. "Modellering av affärsprocesser : FALLSTUDIE PÅ CENTSOFT AB." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177031.
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Många företag har börjat inse att processmodellering kan vara ett bra verktyg för att bättre förstå sitt företag. Att man kan använda processkartor för att analysera och förbättra sina processer.Centsoft AB är ett litet IT-företag med sex anställda som omsätter ca 5,4 miljoner kronor per år. Centsofts huvudsakliga produkt är en webbaserad applikation för elektronisk fakturahantering. I dagsläget har Centsoft ingen dokumentation alls som visar hur dess interna processer ser ut. Därför har studenten fått i uppdrag av Centsoft ABatt kartlägga dess affärsprocesser, analysera dessa och komma med eventuella förbättringsförslag. Arbetet är indelat i tre delar, först genomfördes en förstudie av Centsoft för att förstå dess verksamhet, ta reda på vilka processer det har och produceraen domänbeskrivning. Sedan följde en modelleringsdel under vilken processkartor över verksamheten konstruerades, denna del skedde iterativt för att säkerställa att modellerna blev klara i tid. Arbetet avslutades med en analysdel för att identifiera potentiella förbättringsmöjligheter.Teknik som användes för förbättringsförslag var processförbättring, eftersom process-redesign bedömdes som alltför tidskrävande.Resultatet är elva stycken processkartor, varav två är förbättringsförslag. En av slutsatserna som kunde dras utifrån detta arbete är att Centsoft har välfungerande affärsprocesser som bidrar till att företaget expanderar. Det här arbetet blir en bra grund för Centsoft att arbeta vidare på, t.ex.vid framtida expansioner, då det kanske blir aktuellt att konstruera nya processer, eller ändra befintliga.Many companies have begun to realize process modelling can be a useful tool to better understand their business, and that process maps can beused to analyze and improve the company processes. Centsoft AB is a small IT company with six employees and has revenue of approximately 5.4 million SEK per year. Centsofts main product is aweb-based application for handling electronic invoices.As of today, Centsoft does not have any documentation at all of its internal processes. Therefore Centsoft has given the student an assignment to identify and analyze its business processes, and to come up with any suggestions for improvement.This project is divided into three parts; first part is a case study of Centsoft which is done in order to understand its operations, identify its business processes and to produce a domain description. Second part is to create process maps for the business; this part was done iteratively to ensure that the process maps were delivered on time. The third part is to analyze the process maps for potential improvement opportunities. Technique used to improve the processes was process improvement, because process-redesign was considered too time consuming.The result is eleven process maps, two of which are suggestions for improvement. A conclusion that could be drawn from this project based on the successful expanding and profit-making by Centsoft is that they have well-functioning processes. This project will be a good basis for Centsoft during future expanding, when the need for redesigning existing or designingnew processes arises.
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Swailes, David. "Some topics in industrial mathematics arising from a multi-national company : gel electrophoresis graph matching algorithm; modelling H'+ and K'+ transport across cell membranes; and micellization and adsorption processes in micellar systems." Thesis, University of Strathclyde, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339870.
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Virbukaitė, Laura. "Econometric Modelling and Forecasting Company's FCF Components." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100621_095233-72130.
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The aim of the study is to verify a hypothesis, whether a company’s financial statement items can be modelled using econometric techniques incorporating accounting and macroeconomic variables. For the modelling and forecasting are selected items, necessary to calculate a company’s free cash flow (FCF) of four Lithuanian companies: telecommunication provider TEO LT, cheese manufacturer Rokiškio sūris, producer of household refrigerators Snaigė and distributor and supplier of electric energy VST. From their financial statements are taken such items as operating profit, current assets and current liabilities, long - term assets and long - term liabilities, and modeled as endogenous variables. Two types of exogenous variables are used: accounting variables (revenues and various types of expenditures) and macroeconomic variables (interest rates, disposable income or net earnings, growth of gross domestic product, country’s export, foreign direct investment and inflation). Initial econometric analysis of the variables includes verification of seasonality and stationarity according to the time series graphs and unit - root tests as well as correlation and causality analysis using cross - correlation matrices and Granger causality tests. For the modelling are selected two types of econometric methods: structural simultaneous - equations models (SEM), estimating them using two - stage least squares technique, and vector autoregression (VAR) models. After estimation of the models... [to full text]Darbo tikslas yra patikrinti hipotezę, ar įmonės finansinės atskaitomybės straipsniai gali būti modeliuojami naudojant ekonometrinius metodus įtraukiant apskaitos ir makroekonominius kintamuosius. Modeliavimui ir prognozavimui yra pasirinkti įmonės laisvam pinigų srautui (angl. free cash flow, FCF) apskaičiuoti reikalingi straipsniai ir keturios Lietuvos įmonės: telekomunikacijų paslaugų teikėja „TEO LT“, sūrių gamybos įmonė „Rokiškio sūris“, buitinių šaldytuvų gamintoja „Snaigė“ bei elektros energijos skirstytoja ir tiekėja VST. Iš šių bendrovių finansinių atskaitomybių yra paimti tokie straipsniai, kaip veiklos pelnas, trumpalaikis turtas ir trumpalaikiai įsipareigojimai, ilgalaikis turtas ir ilgalaikiai įsipareigojimai. Šie rodikliai yra modeliuojami kaip endogeniniai kintamieji. Modeliuojant naudojami egzogeniniai kintamieji yra dviejų tipų: apskaitos kintamieji (pardavimai ir įvairios sąnaudos) bei makroekonominiai kintamieji (palūkanų normos, disponuojamos pajamos, neto darbo užmokestis, bendrojo vidaus produkto augimas, šalies eksportas, tiesioginės užsienio investicijos ir infliacija). Pradinė ekonometrinė kintamųjų analizė apima sezoniškumo ir stacionarumo tikrinimą pagal laiko eilučių grafikus ir vienetinės šaknies testus bei koreliacijų ir priežastingumo analizę, naudojant kryžmines koreliacijas ir Granger priežastingumo testus. Modeliavimui yra pasirinkti du ekonometriniai metodai: struktūrinių vienalaikių lygčių modeliai (angl. structural simultaneous – equation... [toliau žr. visą tekstą]
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Pye, John Downing Mechanical & Manufacturing Engineering Faculty of Engineering UNSW. "System modelling of the compact linear Fresnel reflector." Publisher:University of New South Wales. Mechanical & Manufacturing Engineering, 2008. http://handle.unsw.edu.au/1959.4/41244.
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The Compact Linear Fresnel Reflector is a solar thermal energy system currently at prototype stage in Australia. The system uses parallel rows of mirrors lined up underneath a long, elevated thermal absorber. The mirrors move so as to focus solar radiation onto the absorber; the absorber contains a bank of high-pressure water pipes through which water is pumped and gradually boils. The process of ??direct steam generation?? in very long pipes, up to 300 m in a straight run, has not previously been performed at this scale; other systems use shorter pipe runs, or use other fluids such as non-boiling oil. This thesis addresses a broad range of design issues relating to the CLFR prototype and its components. Beam solar radiation at the prototype site is estimated from available data including satellite-derived and ground-based measurements. Existing correlations for the beam component of global radiation do not apply well to Australian conditions so a new correlation is proposed. Computational fluid dynamics simulations establish radiative heat-loss as the dominant mode for the thermal absorber. Results are gathered for a range of sizes and shapes, and heat-loss correlations are derived for use in subsequent simulation. Two-phase flow in the absorber direct-steam-generation process is examined, and a detailed model including, pipe-friction pressure drops, flow-boiling heat transfer and cavity heat loss is presented, with validation against the experimental results of other workers. A series of ??performance maps?? give the predicted outlet flow regime for varied inlet conditions, allowing selection of desired operating points. A full system model is given that integrates this absorber model with ancillary components including the pump and connecting pipework; the model is used to evaluate pumping requirements and to establish expected operating conditions. The inherent pressure instability arising from the two phase flow is examined and orifice plates are sizes to stabilise this effect. A dynamic model for the absorber pipe flow using fully implicit finite difference techniques and accurate IAPWS-IF97 steam properties gives the predicted behaviour during solar transients at both long and short time-scales.
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Jung, Sungyeop. "Physically-Based Compact Modelling of Organic Electronic Devices." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX115/document.
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En dépit d'une amélioration remarquable de la performance des composants électroniques organiques, il y a encore un manque de compréhension théorique rigoureux sur le fonctionnement du composant. Cette thèse est consacrée à la création de modèles pratiques pour composants électroniques organiques à base physique complet, à savoir un modèle compact à base physique. Un modèle compact à base physique d'un élément de circuit est une équation mathématique qui décrit le fonctionnement du composant, et est généralement évaluée par trois critères: si elle est suffisamment simple pour être incorporé dans des simulateurs de circuits, précise pour rendre le résultat des simulateurs utile les concepteurs de circuits et rigoureux pour capturer des phénomènes physiques se produisant dans le composant. Dans ce contexte, les caractéristiques distinctives de l'injection de porteurs de charge et de transport dans les semi-conducteurs organiques sont incorporés dans les modèles avec un effort particulier pour maintenir la simplicité mathématique. L'effet concomitant sur les caractéristiques courant-tension des diodes et des transistors organiques prototypiques sont étudiés. Les méthodes d'extraction des paramètres cohérents aux modèles sont présentés qui permettent la détermination univoque des paramètres de le composant utilisé pour le fonctionnement du composant de modélisation et l'évaluation des performances de le composant et les propriétés des couches minces et des interfaces organiques. Les approches englobent le developement analytique des équations physiques, la simulation numérique à deux dimensions basé sur la méthode des éléments finis et la validation expérimentale. Les modèles compacts originaux et entièrement analytiques et des méthodes d'extraction de paramètres fournissent une compréhension fondamentale sur la façon dont le désordre énergétique dans une couche mince de semi-conducteur organique, décrit par la densité d’etats Gaussienne, affecte les caractéristiques courant-tension observables des composants.Mots-clés : Electronique organique, physique des composants électroniques, modélisation analytique, diodes, transistors à effet de champ, densité d’etats GaussienneIn spite of a remarkable improvement in the performance of organic electronic devices, there is still a lack of rigorous theoretical understanding on the device operation. This thesis is dedicated to establishing practical models of organic electronic devices with a full physical basis, namely a physically-based compact model. A physically-based compact model of a circuit element is a mathematical equation that describes the device operation, and is generally assessed by three criteria: whether it is sufficiently simple to be incorporated in circuit simulators, accurate to make the outcome of the simulators useful to circuit designers, and rigorous to capture physical phenomena occuring in the device. In this context, distinctive features of charge carrier injection and transport in organic semiconductors are incorporated in the models with a particular effort to maintain mathematical simplicity. The concomitant effect on the current-voltage characteristics of prototypical organic diodes and transistors are studied. Parameter extraction methods consistent to the models are presented which enable unambiguity determination of device parameters used for modeling device operation and assessing device performance and properties of organic thin-films and interfaces. The approaches encompass analytical developement of physical equations, two-dimensional numerical simulation based on finite-element method and experimental validation. The original and fully analytical compact models and parameter extraction methods provide fundamental understanding on how energetic disorder in an organic semiconductor thin-film, described by the Gaussian density of states, affects the observable current-voltage characteristics of the devices.Keywords : Organic electronics, device physics, analytical modeling, diodes, field-effect transistors, Gaussian density-of-states
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Persson, Johan. "Modelling and Simulation of Compact Gears for Industrial Robots." Thesis, Linköping University, Linköping University, Department of Management and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16826.
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In order to be competitive in the markets of today, more and more companies try to make their production more effective by automation. Consequently more money is invested in robots and the operability of the robots becomes increasingly important. Undetected faults may result in damages, both to the robot itself and to the operator, which make detection and prediction of faults important.
The gearboxes responsible for controlling the motions of the robots are essential for their functionality. In order to increase the understanding about them this project focuses on creating a model of the stress distribution inside a gearbox.
First, the geometry of the gearbox is measured and digitalized using a vernier caliper, a protractor, a ruler and the CAD-program Solid Works. Then the geometry is imported into the finite element program Samcef.
In Samcef, the interaction between the parts in the gearbox is modeled and a dynamic simulation of the stresses inside the gearbox during a robot cycle performed.
Since there are almost no experience about Samcef at ABB SECRC, part of the project is to evaluate the program and comment the experiences received when using it.
Two main power transmission steps are identified, modeled and simulated. They are merged together into a big model where both steps are present. This model consists of all the essential power transmission inside the gearbox, from input to output. The load applied is a rotational movement on the input axle during a robot cycle.
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Selsil, Alana. "Analytical and numerical modelling of a compact catalytic reformer." Thesis, University of Liverpool, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415761.
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Rajarajan, Muttukrishnan. "Computer modelling of compact photonics devices for optical communications." Thesis, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301050.
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Schwarze, Tobias [Verfasser]. "Compact Environment Modelling from Unconstrained Camera Platforms / Tobias Schwarze." Karlsruhe : KIT Scientific Publishing, 2018. http://www.ksp.kit.edu.
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Shah, Saujanya. "Finite Element Modelling of Compact Gears Using Strain Measurements." Thesis, KTH, Maskinkonstruktion (Avd.), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281777.
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Robot design and development has been the backbone of industrial automation and is in the forefront of accelerated development across all areas. Robot designers have been using simulations for reducing product development lead times. With growing demand for faster, precise and efficient robots, the requirements on computerized simulation for stress analysis has become stringent. While the product structure is mostly designed and developed from scratch, some components are sourced from suppliers, leaving a gap in the knowledge for modelling an entirety of a robot. This thesis applies a structured method to develop a grey-box model of the compact gears, which provides the robots its dexterity in a compact form factor. The method utilizes experimental strain measurements as a basis for building the model. Design of experiment is used as the guide for conducting FE analysis on robot links with unit load case, followed by scaling of stresses to actual load case. Simulated and measured stress plots are compared to conclude on optimum modelling approach. Further, the thesis proposes an alternative method for stress analysis of robot links by omitting the compact gear embodiment. While the method applies well on the robot links considered during the study, its validation across other links and robot architecture is yet to be performed. Finally, recommendations for implementation of proposed method and areas for expanding this thesis work are proposed.Robotdesign har varit ryggraden inom industriell automation och är i framkanten av utvecklingen inom alla områden. Robotdesigners använder sig av simuleringar för att korta utvecklingstider. Med växande krav på snabbare, effektiva och noggranna robotar, har kraven på datorsimuleringar ökat. Medan huvuddelen av strukturen är utvecklad från grunden, är några komponenter köpta från leverantörer vilket skapar ett glapp i kunskapen för att kunna modellera en hel robot. Det här examensarbetet använder en strukturerad metod för att utveckla en "grey-box" modell av en kompaktväxel, vilken tillåter robotens mångsidighet i ett kompakt format. Metoden använder töjningsmätningar till grund för att bygga modellen. Experimentell design används som en guide för att utföra FE analyser på robotdelar med enhetslastfall, vilka skalas till verkliga lastfall. Simulerade och uppmätta spänningar jämförs för att optimera modelleringen. Det föreslås även en metod där kompaktväxlarna inte modelleras som solider. Metoden fungerar väl för robotarmar som ingick i denna studie, dock bör den verifieras på andra modeller och delar. Slutligen föreslås implementering av metoden som tagits fram i denna rapport samt ytterligare arbete för att verifiera metoden.
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CIRILLO, GIOVANNI AMEDEO. "Engineering quantum computing technologies: from compact modelling to applications." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2971119.
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Sulaiman, M. Y. "Performance characteristics of compact heat transfer surfaces." Thesis, University of Brighton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364712.
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Huerta, Escudero Eliu Antonio. "Source modelling of extreme and intermediate mass ratio inspirals." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609770.
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Hadidimoud, S. "Modelling local damage and material rupture (using finite element method)." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/998/.
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Qazi, Nadeem. "Modelling of an axial flow compact separator using neural network." Thesis, Cranfield University, 2009. http://dspace.lib.cranfield.ac.uk/handle/1826/11807.
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A novel design axial flow cyclonic separator called I-SEP was tested with an extensive set of experiments using air-water two phase flow mixture at atmospheric pressure. These experiments provided valuable data on the separation efficiency and pressure drop under different inlet conditions. The performance parameters i.e. Gas Carry Under (GCU) and Liquid Carry Over (LCO) were found to be non-linearly related to the inlet operating conditions. However it was found that resistance on the tangential outlet of the I-SEP affects the GCU and that manipulating the pressure difference between the two outlets and the inlet of the I-SEP through manual control valves, the GCU could be controlled.
The separator was also extensively tested and compared with a gravity separator, when they were placed at the exit of a riser, in severe slugging condition frequently encountered in the production pipe work from some oil fields. The tests revealed that the I-SEP has better tendency to suppress severe slugging as compared to the gravity separator.
A framework for neural network based on multiple types of input was also developed to model the separation performance of the I-SEP. Mutual Information (one of the key elements of the information theory) was applied to select the appropriate candidate input variables to the neural network framework. This framework was then used to develop a neural network model based on dimensionless input parameters such as pressure coefficient. This neural network model produced satisfactory prediction on unseen experimental data.
The inverse function of a trained neural network was combined with a PID controller in a closed loop to control the GCU and LCO at a given set point by predicting the manipulating variable i.e. pressure at the I-SEP outlets. This control scheme was simulated using the test data. Such controller could be used to assist the operator in maintaining and controlling the GCU or LCO at the I-SEP outlets.The work performed during this study also includes the development of a data repository system to store and query the experimental result. An internet based framework is also developed that allows remote access of the experimental data using internet or wireless mobile devices.
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Aymard, François. "Nuclear Statistical Equilibrium for compact stars: modelling the nuclear energy functional." Caen, 2015. http://www.theses.fr/2015CAEN2019.
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Les supernovæ à effondrement de cœur sont l’un des phénomènes connus les plus puissants de l’univers. Elles résultent de l’explosion d’étoiles très massives, ayant brûlé tout leur combustible. Le résidu chaud et compact, appelée proto-étoile à neutrons, se refroidit pour devenir une étoile à neutrons, objet inerte. La dynamique et la structure des étoiles compactes, c’est-à-dire les supernovæ à effondrement de cœur, les proto-étoiles à neutrons et les étoiles à neutrons, ne sont pas encore complètement connues, et sont aujourd’hui au cœur d’intenses recherches, en association avec les observations astrophysiques et les expériences nucléaires. L’un des ingrédients clés de la modélisation d’étoile compacte concerne l’équation d’état. La difficulté de l’obtention d’une équation d’état réaliste et consistante pour tous ces objets stellaires réside dans le fait que l’on doit considérer une large variété de conditions thermodynamiques, c’est-à-dire des valeurs de densités, de fractions de protons et de températures, très différentes. Le travail de cette thèse consiste à modéliser, à partir des degrés de libertés nucléoniques, la structure microscopique ainsi que la composition interne de la matière baryonique des étoiles compactes, afin d’obtenir une équation d’état réaliste et unifiée. En particulier, on est intéressé à utiliser un formalisme qui peut s’appliquer à des densités aussi bien sous-saturées que sur-saturées, et qui, à la limite thermodynamique de température nulle, est compatible avec les interactions effectives modernes et réalistes données par la théorie microscopique d’Hartree-Fock-Bogoliubov et contraintes par les expériences nucléaires. Pour atteindre cet objectif, on présente, pour la matière sous-saturée, un modèle en équilibre statistique nucléaire, qui correspond à une superposition statistique de configurations finies, appelées cellules de Wigner-Seitz. Chaque cellule contient un noyau, ou agrégat, baignant dans un gaz homogène d’électrons ainsi que dans un gaz homogène de neutrons et de protons. Au sein de chaque cellule, on étudie les différentes composantes de l’énergie nucléaire des agrégats en interaction avec les gaz. L’utilisation de la théorie nucléaire de champ moyen pour la description des agrégats ainsi que du gaz de nucléons permet de traiter de façon consistante la matière sous-saturée et la matière sur-saturée. À des densités de plus de deux-trois fois la densité de saturation, l’apparition de degrés de liberté supplémentaires pose de nouveau des problèmes de consitance théorique qui ne sont pas traités dans cette thèse. La thèse est organisée selon trois parties. Dans la partie I, on présente le modèle en équilibre statistique nucléaire, basé sur l’ensemble grand canonique et sur les interactions non relativistes de Skyrme. Des résultats en équilibre β sont présentés, et l’importance de la distribution en masse d’agrégats d’une part, et d’un traitement réaliste de l’énergie libre d’autre part, est discutée. Dans la partie II, on étudie le comportement fonctionnel de l’énergie baryonique des cellules de Wigner-Seitz, en utilisant l’approximation de Thomas-Fermi étendue. En particulier, les effets de volume et de surface dus au milieu stellaire sont étudiés, et leur dépendance en termes de taille et d’asymétrie du noyau, ainsi que de densité et d’asymétrie du gaz de nucléons est analysée. Des résultats préliminaires de l’effet de l’interaction de surface du milieu sont présentés, sous hypothèse de certaines approximations et dans le cas de l’équilibre β. Dans la partie III, on développe des approximations afin d’obtenir une expression analytique fiable de formule de masse, directement reliée à la forme fonctionnelle et aux paramètres de l’interaction de Skyrme. Dans cette partie, on se concentre principalement sur les noyaux dans le vide, et l’on analyse les différentes composantes de l’énergie de liaison en termes de propriétés de volume et de surface, ainsi que de propriétés isoscalaire et isovecteurThe core collapse supernova is one of the most powerful known phenomena in the universe. It results from the explosion of very massive stars after they have burnt all their fuel. The hot compact remnant, the so-called proto-neutron star, cools down to become an inert catalyzed neutron star. The dynamics and structure of compact stars, that is core collapse supernovae, proto-neutron stars and neutron stars, are still not fully understood and are currently under active research, in association with astrophysical observations and nuclear experiments. One of the key components for modelling compact stars concerns the Equation of State. The task of computing a complete realistic consistent Equation of State for all such stars is challenging because a wide range of densities, proton fractions and temperatures is spanned. This thesis deals with the icroscopic modelling of the structure and internal composition of baryonic matter with nucleonic degrees of freedom in compact stars, in order to obtain a realistic unified Equation of State. In particular, we are interesting in a formalism which can be applied both at sub-saturation and super-saturation densities, and which gives in the zero temperature limit results compatible with the microscopic Hartree-Fock-Bogoliubov theory with modern realistic effective in- teractions constrained on experimental nuclear data. For this purpose, we present, for sub-saturated matter, a Nuclear Statistical Equilibrium model which corresponds to a statistical superposition of finite configurations, the so-called Wigner-Seitz cells. Each cell contains a nucleus, or cluster, embedded in a homogeneous electron gas as well as a homogeneous neutron and proton gas. Within each cell, we investigate the different components of the nuclear energy of clusters in interaction with gases. The use of the nuclear mean-field theory for the description of both the clusters and the nucleon gas allows a theoretical consistency with the treatment at saturation and beyond. At densities above two-three times saturation, other degrees of freedom are expected to appear, which potentially lead to other consistency problems but this issue will not be treated in this thesis. The thesis is divided into three parts. In part I, we present the Nuclear Statistical Equilibrium model based on the grand canonical statistics and non-relativistic Skyrme interactions. Results at β-equilibrium are shown and the importance of the clusters distribution as well as a realistic treatment for the free energy model is discussed. Part II investigates the functional behavior of the baryonic energy in the Wigner-Seitz cell within the Extended-Thomas-Fermi approximation. In particular, both bulk and surface in-medium effects are studied, and their dependence on cluster size and asymmetry as well as gas densities and asymmetry is investigated. A preliminary result of in-medium surface effects is presented within some approximations in the case of β-equilibrated matter
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Dideban, Daryoosh. "Statistical modelling of nano CMOS transistors with surface potential compact model PSP." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3257/.
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The development of a statistical compact model strategy for nano-scale CMOS transistors is presented in this thesis. Statistical variability which arises from the discreteness of charge and granularity of matter plays an important role in scaling of nano CMOS transistors especially in sub 50nm technology nodes. In order to achieve reasonable performance and yield in contemporary CMOS designs, the statistical variability that affects the circuit/system performance and yield must be accurately represented by the industry standard compact models. As a starting point, predictive 3D simulation of an ensemble of 1000 microscopically different 35nm gate length transistors is carried out to characterize the impact of statistical variability on the device characteristics. PSP, an advanced surface potential compact model that is selected as the next generation industry standard compact model, is targeted in this study. There are two challenges in development of a statistical compact model strategy. The first challenge is related to the selection of a small subset of statistical compact model parameters from the large number of compact model parameters. We propose a strategy to select 7 parameters from PSP to capture the impact of statistical variability on current-voltage characteristics. These 7 parameters are used in statistical parameter extraction with an average RMS error of less than 2.5% crossing the whole operation region of the simulated transistors. Moreover, the accuracy of statistical compact model extraction strategy in reproducing the MOSFET electrical figures of merit is studied in detail. The results of the statistical compact model extraction are used for statistical circuit simulation of a CMOS inverter under different input-output conditions and different number of statistical parameters. The second challenge in the development of statistical compact model strategy is associated with statistical generation of parameters preserving the distribution and correlation of the directly extracted parameters. By using advanced statistical methods such as principal component analysis and nonlinear power method, the accuracy of parameter generation is evaluated and compared to directly extracted parameter sets. Finally, an extension of the PSP statistical compact model strategy to different channel width/length devices is presented. The statistical trends of parameters and figures of merit versus channel width/length are characterized.
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Jakob, Markus Prüfer. "Compact DC Modelling of Short-Channel Effects in Organic Thin-Film Transistors." Doctoral thesis, Universitat Rovira i Virgili, 2022. http://hdl.handle.net/10803/673905.
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Els transistors orgànics de capa fina (TFT) són dispositius prometedors per a les pantalles flexibles de matriu activa i
els conjunts de sensors, ja que poden fabricar-se a temperatures de procés relativament baixes i, per tant, no sols en
vidre, sinó també en substrats polimèrics. Per a millorar el rendiment dinàmic dels dispositius i circuits TFT , una
reducció agressiva de la longitud de canal provoca efectes extrínsecs en els dispositius que han de ser capturats per
models compactes.
Aquesta tesi presenta models analítics, basats en la física, de la degradació de la pendent subumbral, el roll-off del
voltatge llindar i l'efecte DIBL en TFTs coplanars i escalonats que poden ser implementats en qualsevol model
compacte de corrent continu arbitrari que estigui definit pel voltatge llindar i la pendent subumbral. Per tant, l'equació
diferencial de Laplace es resol per a la geometria coplanar i escalonada aplicant la transformación Schwarz-Cristoffel.
Les solucions del potencial serveixen de base per a la definició de les equacions del model. A més, es desenvolupen
models compactes de les barreres Schottky dependents de la polarització en les interfícies font/semiconductor i
drenador/semiconductor en els TFT coplanars i escalonats, que modelen la injecció i l'ejecció de portadors de càrrega,
respectivament, com a corrent d'emissió termoiònica.Los transistores orgánicos de capa fina (TFT) son dispositivos prometedores para las pantallas flexibles de matriz activa y los conjuntos de sensores, ya que pueden fabricarse a temperaturas de proceso relativamente bajas y, por tanto, no sólo en vidrio, sino también en sustratos poliméricos. Para mejorar el rendimiento dinámico de los dispositivos y circuitos TFT, una reducción agresiva de la longitud de los canales provoca efectos extrínsecos en los dispositivos que tienen que ser capturados por modelos compactos. Esta tesis presenta modelos analíticos, basados en la física, de la degradación de la pendiente subumbral, el roll-off del voltaje umbral y el efecto DIBL en TFTs coplanares y escalonados que pueden ser implementados en cualquier modelo compacto de corriente continua arbitrario que esté definido por el voltaje umbral y la pendiente subumbral. Por lo tanto, la ecuación diferencial de Laplace se resuelve para la geometría coplanar y escalonada aplicando la transformación Schwarz-Christoffel. Las soluciones del potencial sirven de base para la definición de las ecuaciones del modelo. Además, se desarrollan modelos compactos de las barreras Schottky dependientes de la polarización en las interfaces fuente/semiconductor y drenador/semiconductor en los TFT coplanares y escalonados, que modelan la inyección y la eyección de portadores de carga, respectivamente, como corriente de emisión termoiónica
Organic thin-film transistors (TFTs) are promising devices for flexible active-matrix displays and sensor arrays, since they can be fabricated at relatively low process temperatures and thus not only on glass, but also on polymeric substrates. In order to improve the dynamic TFT and circuit performance, an aggressive reduction of the channel length causes extrinsic de-vice effects that have to be captured by compact models. This dissertation presents analytical, physics-based models of the subthreshold-swing degra-dation, the thresholdvoltage roll-off and DIBL effects in coplanar and staggered TFTs that can be implemented in any arbitrary compact dc model that are defined by the threshold voltage and the subthreshold swing. Therefore, Laplace’s differential equation is solved for the coplanar and staggered geometry by applying the Schwarz-Christoffel transformation. The potential solutions serve as a basis for the definition of the model equations. Further-more, compact models of the biasdependent Schottky barriers at the source/semiconductor and drain/semiconductor interfaces in coplanar and staggered TFTs are derived, which model the charge carriers injection and ejection, respectively, as thermionic emission cur-rent. Thereby, in case of the source barrier, the Schottky barrier lowering effect due to im-age charges is captured and therefore, an analytical expression of the electric field at the source barrier is derived.
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Popelková, Ilona. "Purpurové řeky Matematické modelování výkonnosti podniku." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2008. http://www.nusl.cz/ntk/nusl-221785.
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This master's thesis discourse the proposal of the strategy of increasing efficiency of the enterprise. It includes the analysis of the present efficiency level of the company and also a file of math-economical issues, like the riverbed of interconnected flows, whose correct modelling will improve the current entrepreneurial situation.
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Forero-Romero, Jaime E., Max Gronke, Maria Camila Remolina-Gutiérrez, Nicolás Garavito-Camargo, and Mark Dijkstra. "Modelling the gas kinematics of an atypical Ly α emitting compact dwarf galaxy." OXFORD UNIV PRESS, 2018. http://hdl.handle.net/10150/627137.
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Star-forming compact dwarf galaxies (CDGs) resemble the expected pristine conditions of the first galaxies in the Universe and are the best systems to test models on primordial galaxy formation and evolution. Here, we report on one of such CDGs, Tololo 1214-277, which presents a broad, single peaked, highly symmetric Ly alpha emission line that had evaded theoretical interpretation so far. In this paper, we reproduce for the first time these line features with two different physically motivated kinematic models: an interstellar medium composed by outflowing clumps with random motions and an homogeneous gaseous sphere undergoing solid body rotation. The multiphase model requires a clump velocity dispersion of 54.3 +/- 0.6 km s(-1) with outflows of 54.3 +/- 5.1 km s(-1), while the bulk rotation velocity is constrained to be 348(-48)(+75) km s(-1). We argue that the results from the multiphase model provide a correct interpretation of the data. In that case, the clump velocity dispersion implies a dynamical mass of 2 x 10(9) M-circle dot, 10 times its baryonic mass. If future kinematic maps of Tololo 1214-277 confirm the velocities suggested by the multiphase model, it would provide additional support to expect such kinematic state in primordial galaxies, opening the opportunity to use the models and methods presented in this paper to constrain the physics of star formation and feedback in the early generation of Ly alpha - emitting galaxies.
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Lee, Michael Siu Lun. "Compact modelling of partially depleted silicon-on-insulator MOSFETs for analogue circuit simulation." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245003.
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Siegle, Markus. "Behavior analysis of communication systems compositional modelling, compact representation and analysis of performability properties /." Aachen : Shaker, 2002. http://catalog.hathitrust.org/api/volumes/oclc/53805153.html.
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Khosravi, nasab Monireh. "Computational modelling of zeolite N ion exchange properties." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/200718/1/Monireh_Khosravi%20nasab_Thesis.pdf.
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Zeolites are porous alumino-silicate materials with properties that result in a wide range of industrial applications. Predictions of zeolite properties can enhance higher performance and economic value for many industries. In this research, the structure and ion exchange behaviour of synthetic zeolite N is modelled using computational chemistry techniques. Modelled outcomes are compared with experimental data that are also obtained on natural zeolites from two Australian deposits. This research shows that a precise understanding and prediction of zeolite chemical and physical properties can be achieved by correlated atomic-scale modelling and high-quality experimental techniques.
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Tran, Hai. "Investigation of SiGe heterojunction bipolar transistors with respect to compact modelling for integrated circuit design." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ27007.pdf.
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Tran, Hai Carleton University Dissertation Engineering Electronics. "Investigation of SiGe heterojunction bipolar transistors with respect to compact modelling for integrated circuit design." Ottawa, 1997.
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Kamangar, Daniel, and Richard Sundin. "Management and CEO Stock Ownership and its Effect on Company Performance." Thesis, KTH, Matematisk statistik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229670.
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This is a study on the effect of management and CEO stock ownership on company performance. A regression analysis is performed on panel data consisting of a sample of 30 companies listed on OMX Stockholm Mid Cap. A total of 210 and 2520 observations is considered on a yearly and monthly basis, respectively, for seven years (2010-2016). The Hausman test is applied for determining between the fixed effects and random effects regression models. Results show that management relative stock ownership has a significant positive effect on company net income growth and return on assets. The effect is not significant for CEO stock ownership, which is contrary to what commonly has been shown for large companies in previous research. Moreover, alternative methodology is discussed for the benefit of the future researcher. The authors illustrate how the selection of dummy variables can be vital for final model outcomes, and it is thus an important aspect to consider when performing panel data analysis.I den här studien undersöks hur aktieinnehav hos ledning och den verkställande direktören i ett företag påverkar företagsutvecklingen. Studien genomförs med regressionsanalys på paneldata som består av 30 företag, samtliga noterade på OMX Stockholm Mid Cap. Totalt samlas 210 och 2520 observationer på årsbasis respektive månadsbasis över sju år (2010-2016). Hausman-testet används för att bestämma vilken av fixed effects-modellen och random effects-modellen som ska användas i regressionen. Resultaten visar att relativt aktieinnehav hos ledningen har en positiv signifikant påverkan på ett företags nettoinkomstutveckling och avkastning på tillgångar. Den verkställande direktörens aktieinnehav visas inte vara signifikant, vilket är motsatt till det som generellt har visats för stora företag i tidigare forskning. Regressionerna genomförs även med alternativa metoder, vilka det resoneras kring i en diskussion som bör vara till gagn för vidare forskning. Författarna illustrerar hur val av dummy-variabler kan ha en avgörande betydelse för regressionsanalysen, och att det således är en viktig aspekt att ta hänsyn till när regressioner genomförs på paneldata.
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Wei, Zhiliang Jeff. "Compact Fluorescent Lamps phase dependency modelling and harmonic assessment of their widespread use in distribution systems." Thesis, University of Canterbury. Electrical and Computer Engineering, 2010. http://hdl.handle.net/10092/3630.
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This thesis presents the research on CFL's phase dependency modelling to prvodie an improved harmonic assessment of their widespread use in distribution system. Conventionally, CFL is modelled as fixed harmonic current source, which ignores the harmonic interaction with the ac electrical network. However, with different magnitude and phase angle of the applied voltage, CFL's harmonic current injection will be varied. This leads to the methodology of using a Norton equivalent circuit to model CFL's harmonic behaviour.
In a small voltage distortion range, such as 5% VTHD, the CFL admittance is phase dependent with the phase angle of the applied voltage. This dependency character is described by tensors,
which are widely used in physics to represent the invariant relationship between vectors under rotation of coordinate axes. Two methods are purposed to find the optimal value of the linearized admittance tensors on a perturbation level of 3.26% of VTHD. The first method is to average
the tensor results from the original admittance plots based on select points. In the second method, the admittances are rearranged into one double traced circle, and then find the linearized admittance tensor. Both methods show strong agreement and good validity. This also provides an opportunity to analyze the harmonic behaviour of small rating nonlinear electronic devices from a new prospective.
This proposed CFL model is applied to a typical New Zealand distribution network with comparison of using conventional fixed harmonic current source approach. The VTHD caused by large quantity of CFLs is given a more realistic "worst case" scenario. The harmonic interference with
ripple control system is also discussed.
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Fernández, S. Alejandro D. "Modelling the temperature dependences of Silicon Carbide BJTs." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-202754.
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Silicon Carbide (SiC), owing to its large bandgap, has proved itself to be a very viable semiconductor material for the development of extreme temperature electronics. Moreover, its electrical properties like critical field (Ecrit) and saturation velocity (vsat) are superior as compared to the commercially abundant Silicon, thus making it a better alternative for RF and high power applications. The in-house SiC BJT process at KTH has matured a lot over the years and recently developed devices and circuits have shown to work at temperatures exceeding 500˚C. However, the functional reliability of more complex circuits requires the use of simulators and device models to describe the behavior of constituent devices. SPICE Gummel Poon (SGP) is one such model that describes the behavior of the BJT devices. It is simpler as compared to the other models because of its relatively small number of parameters. A simple semi-empirical DC compact model has been successfully developed for low voltage applications SiC BJTs. The model is based on a temperature dependent SiC-SGP model. Studies over the temperature dependences for the SGP parameters have been performed. The SGP parameters have been extracted and some have been optimized over a wide temperature range and they have been compared with the measured data. The accuracy of the developed compact model based on these parameters has been proven by comparing it with the measured data as well. A fairly accurate performance at the required working conditions and correlation with the measured results of the SiC compact model has been achieved.
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Roumy, Mathieu. "Modélisation et pilotage des capacités d’Innovation organisationnelle pour favoriser la capacité d’Innovation de la grande entreprise, cas d’étude : SNCF Réseau." Electronic Thesis or Diss., Bordeaux, 2022. http://www.theses.fr/2022BORD0127.
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Les grandes entreprises évoluent dans un environnement social, climatique, économique et désormais sanitaire, complexe et incertain qui remet en cause le déterminisme mécanique et la logique cartésienne. A cela, s’ajoute une 4ème révolution industrielle. Pour survivre, elles doivent donc évoluer et accroitre leur capacité d’innovation. La majorité des études existantes se sont alors concentrées sur l’innovation technologique, négligeant la dimension non technologique de l’innovation, couramment nommée : « innovation organisationnelle ». Pourtant, cette dernière permet aux grandes entreprises de prendre en compte un ensemble de facteurs qui favorisent leur capacité d’innovation et l’ancre dans leurs routines. L’objectif est alors, grâce à une approche systémique et transdisciplinaire, d’identifier ces facteurs, que nous nommons « capacités d’Innovation Organisationnelle ». Elles regroupent les capacités dynamiques de l’entreprise ainsi que les antécédents de l’innovation organisationnelle. En effet, bien souvent l’innovation non technologique est perçue comme un concept flou et hétéroclite. Il apparait donc nécessaire de doter les entreprises de modèles, méthodes et d’outils qui permettent de rendre le concept concret et opérationnel. Néanmoins, de nos jours, la modélisation d’entreprise présente des limites pour d’une part, la représentation d’une grande entreprise que nous assimilons à un système« Organique » sociotechnique complexe et ouvert et d’autre part pour la représentation et pilotage des capacités d’Innovation Organisationnelle. Ainsi, dans le cadre d’une convention CIFRE avec l’entreprise SNCF Réseau, le laboratoire IMS de l’Université de Bordeaux et le laboratoire Icube de l’Université de Strasbourg, nous proposons un cadre conceptuel de la grande entreprise, de l’innovation organisationnelle ainsi qu’une démarche d’analyse et de préconisation des capacités d’Innovation Organisationnelle, basée sur notre propre modèle de l’innovation organisationnelle pour une grande entreprise.Ce travail de thèse a donc abouti à l’élaboration d’un méta-modèle qui permet à la grande entreprise d’avoir une vision systémique d’elle-même dans le but d’améliorer sa capacité d’innovation. Le modèle se compose de trois systèmes « Organisation-Territoire- Réseau d’acteurs, » et permet de mettre en évidence les capacités d’Innovation Organisationnelle au sein des systèmes dans une logique de caractérisation et de pilotage de celles-ci notamment grâce à l’évaluation de leurs impacts et de leurs priorités. Notre démarche repose sur une étude de cas basée sur une méthodologie quantitative multicritères.Au final, cette thèse est à l’origine de plusieurs contributions. Tout d’abord, le décloisonnement des sciences nous permet d’étudier les antécédents de l’innovation organisationnelle liées au territoire, et aux réseaux d’acteurs, au-delà des approches classiques qui privilégient en général les antécédents internes à l’organisation. Ensuite, nous concédons une place centrale aux dimensions humaines et sociales qui s’avèrent essentielles tout comme l’est une meilleure compréhension de leurs interactions à la fois formelles et informelles (ex : culture d’entreprise, climat social, connaissances, leadership…). Enfin, l’étude de l’impact des capacités d’Innovation Organisationnelle que nous proposons n’a jamais été réalisée auparavant pour une grande entreprise (des travaux sur les PME existent). Ainsi, la capacité d’innovation d’une grande entreprise est dépendante des interactions entre le territoire, les systèmes qui le composent, ses réseaux d’acteurs et les systèmes socio technique de l’organisation. Ces résultats débouchent sur des recommandations pour un meilleur pilotage des capacités d’Innovation Organisationnelle favorisant la capacité d’Innovation qui s’ancre dans la culture de l’entrepriseLarge companies evolve in a complex and uncertain social, climatic, economic and now health environment that challenges mechanical determinism and Cartesian logic. In addition, there is a 4th industrial revolution. To survive, they must evolve and increase their capacity for innovation. Most existing studies have focused on technological innovation, neglecting the non-technological dimension of innovation, commonly called "organizational innovation". However, the latter allows large companies to take into account a set of factors that promote their capacity for innovation and anchor it in their routines. The objective is then, thanks to a systemic and transdisciplinary approach, to identify these factors, which we call "Organizational Innovation capabilities". They include the dynamic capabilities of the company as well as the antecedents of organizational innovation. Indeed, non-technological innovation is often perceived as a vague and heterogeneous concept. It is therefore necessary to provide companies with models, methods and tools that make the concept concrete and operational. Nevertheless, nowadays, enterprise modeling has its limits for, on the one hand, the representation of a large enterprise that we assimilate to a complex and open "organic" socio-technical system and, on the other hand, for the representation and management of Organizational Innovation capacities. Thus, within the framework of a CIFRE agreement with the company SNCF Réseau, the IMS laboratory of the University of Bordeaux and the Icube laboratory of the University of Strasbourg, we propose a conceptual framework of the large company, of organizational innovation as well as an approach of analysis and recommendation of the capacities of Organizational Innovation, based on our own model of the organizational innovation for a large company This thesis work has therefore led to the development of a meta-model that allows the large company to have a systemic vision of itself in order to improve its innovation capacity. The model is composed of three systems "Organization-Territory-Network of actors," and makes it possible to highlight the capacities of Organizational Innovation within the systems in a logic of characterization and piloting of those in particular thanks to the evaluation of their impacts and their priorities. Our approach is based on a case study using a quantitative multi-criteria methodology. In the end, this thesis is the source of several contributions. First, the decompartmentalization of sciences allows us to study the antecedents of organizational innovation linked to the territory and to the networks of actors, beyond the classical approaches that generally privilege the internal antecedents of the organization. Secondly, we give a central place to human and social dimensions, which are essential, as is a better understanding of their interactions, both formal and informal (e.g. corporate culture, social climate, knowledge, leadership, etc.). Finally, the study of the impact of Organizational Innovation capabilities that we propose has never been done before for a large company (work on SMEs exists). Thus, the innovation capacity of a large company is dependent on the interactions between the territory, the systems that make it up, its networks of actors and the socio-technical systems of the organization. These results lead to recommendations for a better management of the organizational innovation capacity that is anchored in the company's culture
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Ahlinder, Stefan. "On modelling of compact tube bundle heat exchangers as porous media for recuperated gas turbine engine applications." [S.l.] : [s.n.], 2006. http://se6.kobv.de:8000/btu/volltexte/2006/15.
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Ahlinder, Stefan [Verfasser]. "On Modelling of Compact Tube Bundle Heat Exchangers as Porous Media for Recuperated Gas Turbine Engine Applications / Stefan Ahlinder." Aachen : Shaker, 2006. http://d-nb.info/1170538037/34.
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Kowalczyk, K. "Boundary and medium modelling using compact finite difference schemes in simulations of room acoustics for audio and architectural design applications." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517381.
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Fazi, Diego <1979>. "Development of a Physical-Template Search for Gravitational Waves from Spinning Compact-Object Binaries with LIGO." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2211/1/PhD_thesis_final.pdf.
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Fazi, Diego <1979>. "Development of a Physical-Template Search for Gravitational Waves from Spinning Compact-Object Binaries with LIGO." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2211/.
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Papucci, Michele. "Electroweak Symmetry Breaking with a compact extra dimension." Doctoral thesis, Scuola Normale Superiore, 2009. http://hdl.handle.net/11384/85837.
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[Excerpt from the preface]: During my Ph.D. course, under the supervision of Riccardo Barbieri, I started
working on Theoretical High Energy Physics. In particular I focused on the problem
of Electroweak Symmetry Breaking and in this context I investigated the
bene ts of introducing a compact extra dimension.
In a series of papers, together with Riccardo Barbieri, Guido Marandella,
Lawrence Hall, Yasunori Nomura, Takemichi Okui and Steven Oliver I built supersymmetric
models in 5D and studied their phenomenology in detail [1, 2, 3, 4].
In this models Supersymmetry is broken by boundary conditions in the fth dimension
and the ElectroWeak Symmetry Breaking is triggered by Supersymmetry
breaking via the top/stop radiative corrections. The phenomenology of these models
is signi cantly di erent than the one of the Minimal Supersymmetric Standard
Model scenarios extensively studied in the literature.
These papers constitute the subject of this Thesis and their results will be
presented in the following Chapters.
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Quilcaille, Yann. "Retour sur les scénarios climatiques et d'émissions à l'aide d'un modèle compact du système Terre." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV041/document.
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Cette thèse met en perspective un ensemble d’éléments des scénarios socio-économiques sous l’angle de la modélisation du climat. Ces éléments contribuent à améliorer la compréhension de l’état actuel des sciences du climat en ce qui concerne les scénarios. En parallèle, ces éléments montrent le potentiel du récent modèle compact du système Terre OSCAR v2.2.Le premier élément concerne l’incertitude des émissions. Bien que les inventaires d’émissions soient incertains, nous ignorons dans quelle mesure ces incertitudes affectent les projections climatiques. Nous quantifions cet impact pour les émissions des énergies fossiles, la principale cause du changement climatique. Nous montrons que ces incertitudes dans les émissions sont amenées à augmenter avec l’utilisation des énergies fossiles non-conventionnelles, mais qu’elles n’augmentent pas de manière significative l’incertitude dans les projections climatiques. Ceci est vrai pour la majeure partie des variables, comme l’augmentation de la température moyenne de surface, mais pas pour certaines qui sont d’intérêt pour la qualité de l’air.Le second élément est une analyse climatique des récents scénarios Shared Socio-Economic Pathways. Nous identifions des failles dans la base de données, que nous comblons. Sur cette base, nous calculons les projections climatiques des scénarios SSP. Nous montrons la présence d’incohérence dans l’utilisation des émissions CO2 dues à l’utilisation des terres (LUC) calculées par les modèles intégrés (IAMs) et des variables associées à l’utilisation des terres. Nous identifions des compromis dans les réductions d’émissions pour l’atténuation du changement climatique. Nous réévaluons de manière plus robuste les budgets carbone. Les incertitudes dans les élévations de températures sont examinées en détail.Le troisième élément concerne les émissions négatives. La plupart des scénarios qui limitent le changement climatique bien en dessous de 2°C par rapport au préindustriel, respectant ainsi l’Accord de Paris, utilisent des émissions négatives. A l’aide d’une version développée de OSCAR v2.2, nous calculons les implications pour le système Terre de plusieurs aspects des techniques d’absorption de dioxyde de carbone (CDR). Nous identifions les réversibilités des différentes parties du système terre, et évaluons le potentiel de refroidissement de ces techniques. Nous montrons aussi que la reforestation pourrait être moins apte à atténuer le changement climatique, du fait du changement dans l’albedo de surface. Par ailleurs, le potentiel d’alcalinisation des eaux de surfaces pour atténuer le changement climatique pourrait être inférieur à celui initialement estimé.Dans l’ensemble, cette thèse identifie des défauts dans le développement actuel des scénarios. Certains ne constituent pas un problème pour les projections climatiques, comme les incertitudes dans le calcul des émissions. D’autres nécessitent une attention particulière, comme le calcul des émissions CO2 dues au LUC par les IAMs ou l’éventuelle surestimation des capacités des techniques de CDR. Ce travail renforce l’urgence du besoin d’atténuation du changement climatiqueThis thesis puts into perspective different elements of socio-economic scenarios from a climate change modelling point of view. These elements contribute at improving the comprehension of the current state of climate sciences regarding the scenarios. In the meantime, these elements demonstrate the potential of the recent reduced-form Earth System Model OSCAR v2.2.The first element concerns the uncertainty of emissions. Although emission inventories are uncertain, we ignore what impact on climate change have these uncertainties. We quantify this impact for fossil-fuel emissions, the major contributor to climate change. We show that the uncertainties in emissions are expected to increase with the use of non-conventional fuels, but that they do not increase significantly the uncertainty from Earth system modelling in variables, such as the increase in global surface temperature.The second element is a climate assessment of the recent Shared Socio-economic Pathways (SSP) scenarios. We identify loopholes in the SSP database, and we complete it to calculate the climate projections under these scenarios. Our conclusions suggest inconsistencies in CO2 emissions from Land Use Change (LUC) calculated by the Integrated Assessment Models and in the associated land variables. We identify trade-offs between greenhouse gases in the mitigation of climate change. Using a robust assessment, new carbon budgets are proposed. The uncertainties in increases in global surface temperature are discussed.The third element concerns the negative emissions. Most climate scenarios limiting global warming well below 2°C above preindustrial levels, thus respecting the Paris Agreement, use negative emissions. Using a developed version of OSCAR v2.2, we evaluate the implications for the Earth system of different aspects of different Carbon Dioxide Removal (CDR) technologies. We identify the reversibility in the different components of the Earth system and calculate the cooling potential of carbon dioxide removal technologies. We also show that the potential of afforestation/reforestation techniques may be impeded by the change in albedo, and that the potential of oceanic enhanced weathering may be lower than expected.Overall, this thesis identifies loopholes in the current development of scenarios. Some do not hinder current conclusions regarding climate change, such as the uncertainties in emission inventories. Others call for further analysis, such as the inconsistencies in the use of CO2 emissions from LUC or the eventual overestimation of the potential of some CDR technologies. It emphasizes the need for an urgent mitigation of climate change
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Habra, Wasim. "Développement de modèles thermiques compacts en vue de la modélisation électrothermique des composants de puissance." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00159791.
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Une nouvelle méthodologie d'extraction de modèles thermiques compacts (CTMs) pour les composants électroniques est proposée dans cette thèse. L'originalité de cette méthodologie réside dans la prise en compte du comportement thermique des composants comportant plusieurs puces ou sources de chaleur, plusieurs surfaces de refroidissement et des matériaux à propriétés non-linéaires, tout en gardant une structure simple et récurrente des modèles générés. Cette méthodologie concerne aussi les modèles thermiques dynamiques, ceci est rendu possible par l'utilisation d'un réseau simple de type " étoile ". La précision du réseau en étoile est améliorée en utilisant des résistances variables liées aux flux thermiques afin que le modèle compact puisse s'adapter à toutes les conditions aux limites possibles. De plus, la méthode choisie permet d'obtenir ceci avec un nombre limité de mesures ou de simulations thermiques 3D. Par ailleurs, tout au long du travail effectué, nous avons choisi de maintenir le lien avec la physique de façon à pouvoir toujours faire les analyses et les interprétations des phénomènes mis en jeu. Ainsi, une étude basée sur les phénomènes de répartition 3D du flux thermique a abouti à des solutions argumentées et validées pour rendre les modèles générés plus précis. L'extension des modèles thermiques compacts au régime dynamique, rendue possible par la méthodologie choisie, est proposée par le biais de trois techniques différentes. L'ajout d'un modèle électrique compatible avec les modèles thermiques développés, rendra aisée la modélisation électrothermique.
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Dia, Cheikh Tidiane. "Génération de modeles compacts thermiques dynamiques de composants electroniques via les algorithmes genetiques." Thesis, Paris 10, 2015. http://www.theses.fr/2015PA100172/document.
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La simulation détaillée au niveau carte de ces nouveaux types de packages est quasiment impossible du fait de la limitation des moyens de calculs actuels. En outre, dans la plupart des cas de conception électronique, seule l’estimation des températures en quelques points est intéressante. Une étude détaillée au niveau composant n’est pas nécessairement pertinente. Il faut donc un compromis entre faisabilité et/ou rapidité des calculs et une précision sur les paramètres importants. Une alternative est de trouver des modèles comportementaux équivalents aux modèles détaillés, capable de reproduire son comportement thermique aux points cruciaux. C’est dans cette optique que le projet européen DELPHI (Development of libraries of physical models of electronic components for an integrated design environment) a été initié en 1993. L’objectif de ce projet était de pouvoir générer un modèle compact à partir d’un modèle détaillé d’un composant électronique. Celui-ci a ainsi abouti à une standardisation du processus de génération des modèles mis en oeuvre. Néanmoins, les avancées issues de ce projet sont limitées aux composants mono-puces et à leur comportement thermique en régime permanent. L’objectif de cette thèse est d’avoir une approche multi-échelle de la génération de modèles compacts et leur interaction avec la carte. La modélisation multi-échelle consiste à la génération de modèles mono-puces ou multi-puces et leur réutilisation éventuelle dans des systèmes plus complexes tels que le PCB ou les « System-In-packages »This thesis is dedicated to the generation of behavioral thermal model for electronic component having multiple active sensitive chips. This innovative study focuses on the necessary improvements of the concept of steady-state and dynamic compact model in order to elaborate pertinent and accurate modeling practical techniques. To help the electronic designer to early identify the overheated electronic components, the purpose is to generate simplified models, capable to mimic the thermal behavior of sophisticated detailed models. These simplified or compact models using well-known thermal resistances network replicate the thermal path from the most sensitive elements to the external package surfaces and enable to accurately predict their temperatures as well as the case heat flow rates. Preliminary evaluations performed on the popular, plastic Quad Flat-pack No lead package family showed that the simplest network definition, restricted to the heating source and two external surfaces, is always insufficient to properly characterize the thermal response of real device. So our development of steady-state compact thermal model (CTM) for electronic component is based on a process flow defined by the European project DELPHI which was revised by the presented work to address multi-chip components. DELPHI style compact thermal model presents an enlarged node number, especially for the component external surfaces which are divided in a set of relevant areas
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Pradeep, Krishna. "Caractérisation et modélisation de la variabilité au niveau du dispositif dans les MOSFET FD-SOI avancés." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT020/document.
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Selon l’esprit de la “loi de Moore” utilisant des techniques innovantes telles que l’intégration 3D et de nouvelles architectures d’appareils, le marché a également évolué pour commencer à imposer des exigences spécifiques aux composants, comme des appareils à faible consommation et à faible fuite, requis par l’Internet des objets (IoT) applications et périphériques hautes performances demandés par les applications 5-G et les centres de données. Ainsi, le secteur des semi-conducteurs s’est peu à peu laissé guider par les avancées technologiques, mais aussi par les applications.La réduction de la tension d’alimentation est encore plus importante pour les applications à faible puissance, comme dans l’IoT, cela est limité par la variabilité du périphérique. L’abaissement de la tension d’alimentation implique une marge réduite pour que les concepteurs gèrent la variabilité du dispositif. Cela nécessite un accès à des outils améliorés permettant aux concepteurs de prévoir la variabilité des périphériques et d’évaluer son effet sur les performances des leur conception, ainsi que des innovations technologiques permettant de réduire la variabilité des périphériques.Cette thèse se concentre dans la première partie et examine comment la variabilité du dispositif peut être modélisée avec précision et comment sa prévision peut être incluse dans les modèles compacts utilisés par les concepteurs dans leurs simulations SPICE. La thèse analyse d’abord la variabilité du dispositif dans les transistors FD-SOI avancés à l’aide de mesures directes. À l’échelle spatiale, en fonction de la distance entre les deux dispositifs considérés, la variabilité peut être classée en unités de fabrication intra-matrice, inter-matrice, inter-tranche, inter-lot ou même entre différentes usines de fabrication. Par souci de simplicité, toute la variabilité d’une même matrice peut être regroupée en tant que variabilité locale, tandis que d’autres en tant que variabilité globale. Enfin, entre deux dispositifs arbitraires, il y aura des contributions de la variabilité locale et globale, auquel cas il est plus facile de l’appeler la variabilité totale. Des stratégies de mesure dédiées sont développées à l’aide de structures de test spécialisées pour évaluer directement la variabilité à différentes échelles spatiales à l’aide de caractérisations C-V et I-V. L’effet de la variabilité est d’abord analysé sur des facteurs de qualité (FOM) sélectionnés et des paramètres de procédés extraits des courbes C-V et I-V, pour lesquels des méthodologies d’extraction de paramètres sont développées ou des méthodes existantes améliorées. Cette analyse aide à identifier la distribution des paramétres et les corrélations possibles présentes entre les paramètres.Ensuite, nous analysons la variabilité dépendante de la polarisation dans les courbes I-V et C-V. Pour cela, une métrique universelle, qui fonctionne quelle que soit l’échelle spatiale de la variabilité, est definée sur la base de l’analyse des appariement précédemment rapportée pour la variabilité locale. Cette thèse étend également cette approche à la variabilité globale et totale. L’analyse de l’ensemble des courbes permet de ne pas manquer certaines informations critiques dans une plage de polarisation particulière, qui n’apparaissaient pas dans les FOM sélectionnés.Une approche de modélisation satistique est utilisée pour modéliser la variabilité observée et identifier les sources de variations, en termes de sensibilité à chaque source de variabilité, en utilisant un modèle physique compact comme Leti-UTSOI. Le modèle compact est d’abord étalonné sur les courbes C-V et I-V dans différentes conditions de polarisation et géométries. L’analyse des FOM et de leurs corrélations a permis d’identifier les dépendances manquantes dans le modèle compact. Celles-ci ont également été incluses en apportant de petites modifications au modèle compactThe ``Moore's Law'' has defined the advancement of the semi-conductor industry for almost half a century. The device dimensions have reduced with each new technology node, and the design community and the market for the semiconductor have always followed this advancement of the industry and created applications which took better advantage of these new devices. But during the past decade, with the device dimensions approaching the fundamental limits imposed by the materials, the pace of this scaling down of device dimensions has decreased. While the technology struggled to keep alive the spirit of ``Moore's Law'' using innovative techniques like 3-D integration and new device architectures, the market also evolved to start making specific demands on the devices, like low power, low leakage devices demanded by Internet of Things (IoT) applications and high performance devices demanded by 5-G and data centre applications. So the semiconductor industry has slowly moved away from being driven by technology advancement, and rather it is now being driven by applications.Increasing power dissipation is an unavoidable outcome of the scaling process, while also targeting higher frequency applications. Historically, this issue has been handled by replacing the basic transistors (BJTs by MOSFETs), freezing the operation frequency in the system, lowering supply voltage, etc. The reduction of supply voltage is even more important for low power applications like in IoT, but this is limited by the device variability. Lowering the supply voltage implies reduced margin for the designers to handle the device variability. This calls for access to improved tools for the designers to predict the variability in the devices and evaluate its effect on the performance of their design and innovations in technology to reduce the variability in the devices. This thesis concentrates in the first part, and evaluates how the device variability can be accurately modelled and how its prediction can be included in the compact models used by the designers in their SPICE simulations.At first the thesis analyses the device variability in advanced FD-SOI transistors using direct measurements. In the spatial scale, depending on the distance between the two devices being considered, the variability can be classified into intra-die, inter-die, inter-wafer, inter-lot or even between different fabs. For the sake of simplicity all the variability within a single die can be grouped together as local variability, while others as global variability. Finally between two arbitrary device, there will be contributions from both local and global variability, in which case it is easier to term it as the total variability. Dedicated measurement strategies are developed using specialized test structures to directly evaluate the variability in different spatial scales using C-V and I-V characterisations. The effect of variability is first analysed on selected figure of merits (FOMs) and process parameters extracted from the C-V and I-V curves, for which parameter extraction methodologies are developed or existing methods are improved. This analysis helps identify the distribution of the parameters and the possible correlations present between the parameters.A very detailed analysis of the device variability in advanced FD-SOI transistors is undertaken in this thesis and a novel and unique characterisation and modelling methodology for the different types of variability is presented in great detail. The dominant sources of variability in the device behaviour, in terms of C-V and I-V and also in terms of parasitics (like gate leakage current) are identified and quantified. This work paves the way to a greater understanding of the device variability in FD-SOI transistors and can be easily adopted to improve the predictability of the commercial SPICE compact models for device variability
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Kiša, Daniel. "Matematické modelování kráčejících robotů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417089.
Full textAbstract:
Tato diplomová práce se zabývá matematickými modely kráčejících robotů. Dva z těchto modelů jsou vybrány a analyzovány. Pasivní model "rimless wheel" , který slouží jako základ pro další, složitější modely, je podrobně analyzován. "Compass gait" model dvounohého robota je v práci analyzován a numericky simulován v programovacím jazyce Python. Metoda pro nalezení podmínek pro pasivní chůzi robota je rovněž implementována.