• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 4
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 32
  • 11
  • 10
  • 8
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Analysis of Torque Vectoring Systems through Tire and Vehicle Model Simulation

Chatfield, Christopher 08 August 2023 (has links)
No description available.
22

The Predictive Power of Organizational Culture and Social Quality Relationships on Environmental Services Departmental Turnover Intent

Godsey, Donell 30 November 2022 (has links)
No description available.
23

Control of distributed energy storage and EVs in building communities

Zigga, Kweku, Nasir, Usman January 2023 (has links)
This study delves into the comparative operational effectiveness of non-coordinated, bottom-up, and top-down coordinated control models within Distributed Energy Storage Systems (DESS) and Electric Vehicle (EV) networks. Employing meticulous data analysis, this research evaluates power demand and supply dynamics within the infrastructure and buildings, aiming to optimize energy usage and storage. The analysis involves comprehensive steps: descriptive statistical breakdown, understanding energy patterns across buildings, and a comparative assessment of the control models. Visual representations and graphs aid in depicting energy patterns, emphasizing the distinctive characteristics and effectiveness of each control model. The findings reinforce the superiority of the top-down coordinated control model in managing supply-demand imbalances, echoing established literature.
24

Three essays on skill-specific labor markets, inequality and consumption over the business cycle

Xie-Uebele, Runli 21 June 2011 (has links)
Diese Dissertation befasst sich mit Arbeitsmarkterfolg und Konsum sozioökonomischer Gruppen. Die ersten zwei Kapitel untersuchen konjunkturelle Auswirkungen auf Arbeitsmärkten für Hoch- und Niedrigqualifizierte. Zunächst wird ein qualifikationsspezifisches Konjunkturmodell mit Suchkosten entworfen. Es zeigt, dass imperfekte Substitution zwischen hoch- und niedrigqualifizierter Arbeit ein Grund für Veränderungen auf den Teilmärkten ist. Gemeinsam mit qualifikationsneutralen und -verzerrten Technologieschocks ist das Modell in der Lage, fallende Beveridge-Kurven zu generieren. Das zweite Kapitel erweitert diesen Ansatz um eine Verbindung zwischen qualifikationsabhängigen Arbeitsmärkten mit endogenen Investitionen in Humankapital. Idiosynkratische Schocks wirken auf den Anteil qualifizierter Arbeit und verändern die Arbeitsmarktdichte auf den Teilmärkten. Neutrale Schocks wirken zweistufig auf die Gesamtarbeitslosigkeit: Zuerst reduzieren sie geringqualifizierte Arbeitslosigkeit, und dann verringern sie rapide hochqualifizierte Arbeitslosigkeit. Eine hohe Substitutions-Elastizität zwischen den beiden Qualifikationen führt zu einer höheren Volatilität und einer höheren Korrelation zwischen Arbeitslosigkeit und freien Stellen. Das dritte Kapitel untersucht die Verbindung zwischen Gruppen-Konsumwachstum und dessen Volatilität, wenn die Agenten heterogen sind und eine Konsumexternalität vorliegt. Die Präferenzen der Haushalte hängen mit der Konsumwachstumsvolatilität insofern zusammen, als diese Vermögensentscheidungen treffen müssen: Die Volatilität verringert sich mit der Geduld und steigt mit dem Wunsch, das Konsumniveau der Vergleichsgruppe zu halten. Darüber hinaus sollten Konsumwachstum und dessen Volatilität positiv korrelieren. Diese letzte Hypothese wird mit Daten aus dem Sozio-oekonomischen Panel und der Einkommens- und Verbrauchsstichprobe überprüft, wobei sich ein U-förmiger Zusammenhang zwischen Konsumwachstum kurzlebiger Güter und dessen Volatilität ergibt. / This dissertation addresses the labor market performance and consumption dynamics of different socioeconomic groups. The first part examines the connection between cyclical variations in skilled and unskilled labor markets. Using a business cycle model with search frictions in skill-specific markets, I find that imperfect substitution between skilled and unskilled labor creates an important channel for variations in the skill-specific markets. Together with a skill-neutral or -biased technology shock, the model generates downward-sloping Beveridge curves in aggregate and skill-specific labor markets. I extend the study to allow for a dynamic link between the skill-specific labor markets. Human capital investment is determined endogenously and idiosyncratic shocks shift the skilled labor share and change tightness in both skilled and unskilled markets. Upon a neutral shock, the decrease of total unemployment is two-staged: Firstly with a reduction in unskilled unemployment, and then with a sharp decline of skilled unemployment when skill substitution dominates. A larger elasticity of substitution between the two types of labor leads to higher volatility of the model variables and higher correlation between unemployment and vacancies. The second part studies the link between group-specific consumption growth and its volatility in a framework of heterogeneous agents, under the assumption of a consumption externality. Household preferences are related to the consumption growth volatility through asset holding decisions: The volatility decreases with groups'' patience, and increases with the eagerness to keep up with the group average. Moreover, consumption growth is expected to be positively related to its volatility. This last hypothesis is tested using household data imputed from the German Socio-Economic Panel and the German Income and Expenditure Survey, where a U-shaped relationship is found between nondurable consumption growth and its volatility.
25

Quality Assuring of Stator Winding Production : Using electrical tests to quality assure the process steps of a series stator winding production

Sayed Hamad, Tarek January 2021 (has links)
The demands for sustainable transportation have made battery electric vehicles an increasingly popular subject in the world of both businesses and engineering. This thesis has been made in collaboration with Scania, which is currently investigating the possibility of manufacturing stators and rotors in-house in a series production line. For Scania, the topic of quality assurance is of great importance as Scania wants to ensure their trucks and buses fulfil the quality requirements of both customers and society. The goal of the thesis is to provide Scania with a set of guidelines for what quality assurance steps to perform in a series stator winding production, and where in the production they should be placed. The investigated stator winding type is a continuous hairpin winding, and the investigated quality assurance steps are solely electrical tests used to ensure the safety, functionality, and quality of the stator windings. A process-failure modes and effects analysis were conducted to identify the risks associated with each production step. The results indicates where the quality assurance steps should be taken. Further analysis, based on the provided background of electrical tests, also provides an answer to what electrical tests to perform as quality assurance steps. The result of the thesis is a concept, presented in a flow chart diagram, which indicates what electrical tests to perform and where the tests should be performed in the stator winding production chain. / De krav som sätts på hållbar transport har gjort batteridrivna elektriska fordon ett alltmer populärt ämne i världens företag och ingenjörskonst. Denna avhandling har gjort i samarbete med Scania, som i nuläget utreder möjligheterna för att tillverka statorer och rotorer in- house i en serie produktionslinje. För Scania är ämnet kvalitetssäkring (QA) ett viktigt ämne, för att Scania vill säkerställa att deras lastbilar och bussar lever upp till de kvalitetskrav som både kunder och samhället ger. Avhandlingens mål är därför att förse Scania med en uppsättning av riktlinjer för vilka QA steg som ska utföras i en serie statorlindningsproduktion, och var i produktionen de ska placeras. Den statorlindningstypen i fokus är en kontinuerlig hårnålslindning, och att de kvalitetssäkringar som undersöks är enbart elektriska test som säkrar säkerhet, funktionalitet samt kvalitén av statorlindningarna. En P-FMEA har utförts som en risk och felläges analys i syfte att identifiera de risker som är associerat med varje produktionssteg. Resultatet pekar på var QA steg ska utföras någonstans. Fortsatt analys, baserat på den givna bakgrunden av elektriska test, ger även ett svar på vilka elektriska test som ska utföras som QA steg. Avhandlingens resultat är ett koncept, presenterat i ett flödesdiagram, som visar vilka elektriska test som ska utföras samt var dessa tests ska utföras i statorlindningsproduktionen.
26

Modelos de programação matemática para o gerenciamento de energia em modernos sistemas de distribuição de energia elétrica / Models of mathematical programming for energy management in modern electricity distribution systems

Ñahuis, Fernando Vladimir Cerna [UNESP] 17 February 2017 (has links)
Submitted by FERNANDO VLADIMIR CERNA ÑAHUIS null (fvcerna83@gmail.com) on 2017-02-22T17:36:35Z No. of bitstreams: 1 TESE-FINAL.pdf: 2994686 bytes, checksum: 5e487b40d4aeb0006f40a0abdb9d9af6 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-02-24T20:11:29Z (GMT) No. of bitstreams: 1 nahuis_fvc_dr_ilha.pdf: 2994686 bytes, checksum: 5e487b40d4aeb0006f40a0abdb9d9af6 (MD5) / Made available in DSpace on 2017-02-24T20:11:29Z (GMT). No. of bitstreams: 1 nahuis_fvc_dr_ilha.pdf: 2994686 bytes, checksum: 5e487b40d4aeb0006f40a0abdb9d9af6 (MD5) Previous issue date: 2017-02-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesta tese são apresentados três modelos de programação matemática que abordam os problemas de otimização relacionados ao gerenciamento da energia nos sistemas de distribuição de energia elétrica (SDEE), como: 1) Programação ótima das entregas e carregamento dos veículos elétricos (VEs) durante a navegação em um mapa de cidade, 2) Gerenciamento ótimo pelo lado da demanda considerando um sistema fotovoltaico híbrido (SFH) em uma residência em baixa tensão (RBT) no SDEE, e 3) O melhoramento do fator de carga (FC) do SDEE através do controle da demanda. O primeiro problema visa minimizar os custos relacionados com a manutenção e geração de horas extra durante a operação de uma frota de VEs, levando em conta um conjunto de entregas pre-especificadas, assim como, pontos de carregamento alocados ao longo de cada via urbana (principal e/ou secundária) pertencente ao mapa da cidade. No segundo problema, para uma residência em baixa tensão é planejado um perfil ótimo de consumo para o dia seguinte. Este perfil de consumo é obtido através de um programa de gerenciamento pelo lado da demanda (GLD) que considera uma estrutura tarifária e um esquema de operação que otimiza os recursos energéticos vindos de um SFH e o SDEE. Para cada problema de otimização é apresentado o seu correspondente modelo de programação não linear inteiro misto (PNLIM). O terceiro problema visa minimizar os custos por compra de energia (consumo e perdas de potência ativa) da concessionária, levando em conta, o controle da demanda dos usos-finais, presentes nas unidades consumidoras (residenciais, comerciais, e industriais) no SDEE. As incertezas na utilização dos usos-finais nas unidades consumidoras são simuladas através de um algoritmo Monte Carlo. Além disso, o modelo proposto PIMRQ é rodado dentro de um processo iterativo, que visa a melhoria do FC do SDEE. Por outro lado, através destes modelos não-lineares, a solução ótima global não é garantida, enquanto o uso de modelos equivalentes (para o primeiro e segundo problema, sendo um modelo aproximado para o terceiro) de programação linear inteira mista (PLIM) resolvidos por ferramentas de otimização clássica existentes garantem a convergência para a solução ótima global. Por conseguinte, para resolver este inconveniente, os seus modelos MILP equivalentes são obtidos e explicados em detalhe. Os modelos propostos foram implementados na linguagem de modelagem algébrica AMPL e resolvidos usando o solver comercial CPLEX. Além disso, algoritmos de simulação para representar as incertezas dos tempos de demora na operação dos VEs e os hábitos de utilização dos usos-finais durante o dia, são desenvolvidos. Um grafo unidirecional de 71 nós, uma rede elétrica IEEE de 34 nós, e 21 usos-finais (incluído um VE plug-in para o carregamento na residência) residenciais são utilizados para testar a precisão e a eficiência, assim como, também técnica de solução dos modelos propostos para cada problema. / This thesis presents three mathematical programming models to address the optimization problems related to the energy management in the electricity distribution systems (EDSs), such as: 1) Optimal delivery scheduling and charging of electric vehicles (EVs) in the navigation of a city map, 2) Optimal demand side management of an EDS considering a hybrid photovoltaic system (HPS) in a residential low voltage (RLV), and 3) Load factor improvement through the demand control in the EDS. The first problem aims at minimizing the costs related to the maintenance and generation of extra hours during the operation of a EVs fleet, taking into account a number of prespecified deliveries, as well as charging points allocated along each urban road (main or secondary) belongs to the city map. In the second problem, for a RLV, an optimal consumption profile of a day-ahead is planned. This consumption profile is obtained through a demand side management (DSM) program that considers a tariff structure and an operating scheme that optimizes the energy resources coming from HFS and EDS. The third problem aims at minimizing the costs of energy purchase (consumption and active energy losses) of the company, taking into account, the demand control of the end-uses, presents in the consumers units (residential, commercial, and industrial) in the EDS. Uncertainties in the use of the end-uses in the different consumer units are simulated through a Monte Carlo algorithm that determines a habitual consumption profile for EDSs. Based on this habitual profile, the proposed MIPRQ model determines an optimal profile for EDSs. This model uses an iterative process that aims to improve the load factor of the EDS. For each optimization problem the corresponding non-linear mixed integer programming (NLMIP) model is presented. On the other hand, via these nonlinear models, the global optimal solution is not guaranteed, while using the equivalent mixed-integer linear (MILP) models (for the first and second problems, being an approximate model for the third) and solving them by existing classical optimization tools ensures convergence to global optimal solution. Therefore, in order to address this drawback, their equivalent mixed integer linear programming (MILP) models are obtained and explained in detail. The proposed models are implemented in the algebraic modeling language AMPL and solved using the commercial CPLEX solver. Moreover, simulations algorithms to represent the uncertainties of delay times in the operation of EVs and usage habits of end-uses during the day, are developed. A multidirectional graph with 71 nodes, an electrical network IEEE 34 nodes, and a quantity of 21 residential end-uses (including an EV plug-in for residential charging) are used to test the precision and the efficiency, as well as the solution technique of the models proposed for each problem. / CNPq: 141462/2013- 2
27

Modelos de programação matemática para o gerenciamento de energia em modernos sistemas de distribuição de energia elétrica /

Ñahuis, Fernando Vladimir Cerna. January 2017 (has links)
Orientador: Marcos Júlio Rider Flores / Resumo: Nesta tese são apresentados três modelos de programação matemática que abordam os problemas de otimização relacionados ao gerenciamento da energia nos sistemas de distribuição de energia elétrica (SDEE), como: 1) Programação ótima das entregas e carregamento dos veículos elétricos (VEs) durante a navegação em um mapa de cidade, 2) Gerenciamento ótimo pelo lado da demanda considerando um sistema fotovoltaico híbrido (SFH) em uma residência em baixa tensão (RBT) no SDEE, e 3) O melhoramento do fator de carga (FC) do SDEE através do controle da demanda. O primeiro problema visa minimizar os custos relacionados com a manutenção e geração de horas extra durante a operação de uma frota de VEs, levando em conta um conjunto de entregas pre-especificadas, assim como, pontos de carregamento alocados ao longo de cada via urbana (principal e/ou secundária) pertencente ao mapa da cidade. No segundo problema, para uma residência em baixa tensão é planejado um perfil ótimo de consumo para o dia seguinte. Este perfil de consumo é obtido através de um programa de gerenciamento pelo lado da demanda (GLD) que considera uma estrutura tarifária e um esquema de operação que otimiza os recursos energéticos vindos de um SFH e o SDEE. Para cada problema de otimização é apresentado o seu correspondente modelo de programação não linear inteiro misto (PNLIM). O terceiro problema visa minimizar os custos por compra de energia (consumo e perdas de potência ativa) da concessionária, levando em conta, o co... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor
28

Způsoby ocenění nemovitostí ve Velké Británii se zaměřením na rodinné domy. / Valuation of real estate in the UK, with a focus on family homes.

Banzetová, Diana January 2015 (has links)
This thesis deals with residential real estate market in the Great Britain and its development. The thesis describes all evalution methods used in the Great Britain, it also describes the current state of the property market, expert work and in the end are described in detail the methods used for the valuation of the house. In thesis attachment is an exemplar of the evalution report for a house in the Great Britain according to the standards and the methodologies used by the evaluation experts in the United Kingdom.
29

Assessment of High Purity Mesenchymal Stromal Cells Derived Extracellular Vesicles Presenting NRP1 Show Functional Suppression of Activated Immune Cells

Gobin, Jonathan 04 January 2022 (has links)
Background: The focus of this study was to investigate how producing human bone marrow (hBM) derived mesenchymal stromal cell (MSC) extracellular vehicles (EVs) in a high purity isolation system would affect their established characterization criteria and address the validity of these methods of EV production. Additionally, we set out to functionally characterize the hBM-MSC-EVs for their identified immunomodulatory ability while also assessing the presence of novel MSC-EV marker NRP1 identified by our group to further affirm its validity as a functional MSC-EV identity marker. Methods: Each hBM-MSC-EV donor was cultured in a hollow-fiber bioreactor system in non-stimulating serum/xeno-free conditions for 25 days to produce EVs persistently under quiescent conditions to characterize the hBM-MSC-EVs in their native form. EVs were isolated by traditional PEG-based precipitation for preliminary characterization to monitor bioreactor production wherein they were characterized using multimodal tangential flow filtration coupled with fast protein liquid chromatograph (FPLC) size exclusion/high-affinity purifications to obtain the final highly purified EV sample. Additionally, functional analysis of their immunomodulatory ability, EVs and MSCs were incubated with activated peripheral blood mononuclear cells (PBMCs) as an in-vitro model to evaluate their potency. Results: The hBM-MSC-EVs produced from the bioreactor system showed consistent characterization in accordance with the MISEV2018 establish criteria. We were also able to demonstrate their functional ability by observing statistically significantly immunomodulatory ability of activated PBMCs equivalent to native MSC ability. We were also able to validate the present of NRP1 on all hBM-MSC-EV samples produced confirming its validity as a MSC-EV marker. Conclusion: The significance of the results obtained from this study confirms the production of MSC-EV using a bioreactor and high purity isolation for obtaining consistent MSC-EVs for downstream investigation. Additionally, we were able to demonstrate the significance of MSC-EVs on MSC signaling for immunomodulation by showing equivalent functional potency when tested in-vitro. These results contribute to further understanding the biological attributes of MSC-EVs and contribute to the validation of currently established characterization guidelines.
30

Vývoj tlumočnických dovedností / Interpreting skills development

Rambousková, Hana January 2016 (has links)
The present thesis addresses the issue of the impact of two independent variables - speech rate and interpreters' experience - on the length of time lag in simultaneous interpreting from English to Czech. Time lag, or ear-voice-span (EVS), in simultaneous interpreting is the time difference between the input in source language and the output in target language. The study comprises of two parts. The first, theoretical part summarises the current state of research on the subject. The second, empirical part compares the average EVS in excerpts of sixty simultaneous interpreting renditions uttered by forty-nine subjects divided into two speech rate categories and three experiential categories. The aim is to find out, firstly, whether there are any differences in EVS length based on speech rate, and, secondly, how the interpreters' level of experience influences their EVS length. The first main finding is that a higher speech rate leads, on average, to a shorter EVS than an optimal speech rate; this does not, however, apply in the case of professional interpreters - their EVS length is not affected by speech rate. The second main finding is that the interpreters' level of experience influences EVS length significantly: the more experienced the subjects, the shorter their EVS on average. While evaluating...

Page generated in 0.0411 seconds