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  • 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.
31

Modeling sustainability in complex urban transportation systems

Azevedo, Kyle Kellogg 30 August 2010 (has links)
This thesis proposes a framework to design and analyze sustainability within complex urban transportation systems. Urban transit systems have large variability in temporal and spatial resolution, and are common in lifecycle analyses and sustainability studies. Unlike analyses with smaller scope or broader resolution, these systems are composed of numerous interacting layers, each intricate enough to be a complete system on its own. In addition, detailed interaction with the system environment is often not accounted for in lifecycle studies, despite its strong potential effects on the problem domain. To manage such complexity, this thesis suggests a methodology that focuses on integrating existing modeling constructs in a transparent manner, and capturing structural and functional relationships for efficient model reuse. The Systems Modeling Language (OMG SysML ) is used to formally implement the modeling framework. To demonstrate the method, it is applied to a large scale multi-modal transportation network. Analysis of key network parameters such as emissions output, well-to-wheel energy use, and system capacity are presented in a case study of the Atlanta, Georgia metropolitan area. Results of the case study highlight several areas that differ from more traditional lifecycle analysis research. External influences such as regional electricity generation are found to have extremely large effects on environmental impact of a regional mobility system. The model is used to evaluate various future scenarios and finds that existing policy measures for curbing energy use and emissions are insufficient for reducing impact in a growing urban region.
32

Variants of compound models and their application to citation analysis

Low, Wan Jing January 2017 (has links)
This thesis develops two variant statistical models for count data based upon compound models for contexts when the counts may be viewed as derived from two generations, which may or may not be independent. Unlike standard compound models, the variants model the sum of both generations. We consider cases where both generations are negative binomial or one is Poisson and the other is negative binomial. The first variant, denoted SVA, follows a zero restriction, where a zero in the first generation will automatically be followed by a zero in the second generation. The second variant, denoted SVB, is a convolution model that does not possess this zero restriction. The main properties of the SVA and SVB models are outlined and compared with standard compound models. The results show that the SVA distributions are similar to standard compound distributions for some fixed parameters. Comparisons of SVA, Poisson hurdle, negative binomial hurdle and their zero-inflated counterpart using simulated SVA data indicate that different models can give similar results, as the generating models are not always selected as the best fitting. This thesis focuses on the use of the variant models to model citation counts. We show that the SVA models are more suitable for modelling citation data than other previously used models such as the negative binomial model. Moreover, the application of SVA and SVB models may be used to describe the citation process. This thesis also explores model selection techniques based on log-likelihood methods, Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The suitability of the models is also assessed using two diagrammatic methods, randomised quantile residual plots and Christmas tree plots. The Christmas tree plots clearly illustrate whether the observed data are within fluctuation bounds under the fitted model, but the randomised quantile residual plots utilise the cumulative distribution, and hence are insensitive to individual data values. Both plots show the presence of citation counts that are larger than expected under the fitted model in the data sets.
33

The application of multivariate statistical analysis and batch process control in industrial processes

Lin, Haisheng January 2010 (has links)
To manufacture safe, effective and affordable medicines with greater efficiency, process analytical technology (PAT) has been introduced by the Food and Drug Agency to encourage the pharmaceutical industry to develop and design well-understood processes. PAT requires chemical imaging techniques to be used to collect process variables for real-time process analysis. Multivariate statistical analysis tools and process control tools are important for implementing PAT in the development and manufacture of pharmaceuticals as they enable information to be extracted from the PAT measurements. Multivariate statistical analysis methods such as principal component analysis (PCA) and independent component analysis (ICA) are applied in this thesis to extract information regarding a pharmaceutical tablet. ICA was found to outperform PCA and was able to identify the presence of five different materials and their spatial distribution around the tablet.Another important area for PAT is in improving the control of processes. In the pharmaceutical industry, many of the processes operate in a batch strategy, which introduces difficult control challenges. Near-infrared (NIR) spectroscopy is a non-destructive analytical technique that has been used extensively to extract chemical and physical information from a product sample based on the scattering effect of light. In this thesis, NIR measurements were incorporated as feedback information into several control strategies. Although these controllers performed reasonably well, they could only regulate the NIR spectrum at a number of wavenumbers, rather than over the full spectrum.In an attempt to regulate the entire NIR spectrum, a novel control algorithm was developed. This controller was found to be superior to the only comparable controller and able to regulate the NIR similarly. The benefits of the proposed controller were demonstrated using a benchmark simulation of a batch reactor.
34

Zlepšení vybraného procesu: kreativně a systémově / Improving the selected process: creatively and systematically

Ženíšek, Jan January 2014 (has links)
This diploma thesis describes the design of an efficient optimization of the selected process. The thesis contains description of methods supporting creative and systematic approach to the problem, with an accent on discipline system dynamics and its instruments for system analysis. It thus offers a tool through which you can capture, analyze and model the selected process in a new way, to discover the causes of problems and predict their behavior. Creative application of methods and systems approach is chosen optimum alternative solution of the problem, which is then constructed to compare model simulations in order to determine whether the selected process improvements effectively.
35

Automatic Creation of an Aircraft Structural Layout and Structural Analysis Model : A method for implementing design automation in an early conceptual design phase

Brånäs, Philip, Enderby, Nora January 2022 (has links)
Aircraft structural layout concept design at Saab Aeronautics utilize thickness optimizationto evaluate astructural layout concept. The thickness values can be used to compare conceptsto each other,and the bestonecan be further developed. Today, most ofthe creation and evaluation of structural layout concepts is manual work. Therefore, there is an ongoing investigation on how to implement design automation to reduce this manual and repetitive work. The investigationaims to achieve rapid exploration of the design space to find a good base for a new aircraft development. This includes investigating how the synchronization between a structural layout model (SLM) and a global finite element model (GFEM) can be improved. This thesis contributes to the investigation by exploring the possibilities to implement design automation in the creation of the SLM regarding the fuselage structure. Further, exploring the implementation of design automation in the creation of the GFEM to enable automatic evaluation of concepts. The thesis also explores how the synchronization between the models can be improved. To structure the thesis work, the software development methodologies of MOKA and RAD weremodified and combined. The execution of the thesis was carried out in the software of 3DEXPERIENCE, particularly using the applications CATIAand SIMULIA. This thesis work resulted in a methodfor developing and evaluating aircraft structure concept designs with design automation. The new method includes two models with corresponding scripts. The first model developed is a tool for a conceptualdesignerthat enables the creation of aircraft fuselage SLM from user defined inputs. The second model is generated by script which results in a GFEM with a direct connection to the SLM. To conclude, the developed method enables a faster iteration work of fuselage structural concept designs compared to the current method. The detail level is lower but more consistent and uniform. The GFEM was not able to fulfil its purpose in the developed method due to time limits and software limitations. However, the synchronization between the SLM and GFEM was implemented successfully and contained all critical elements.
36

Från modellering till dimensionering : Att modifiera produktionsmodeller till analysmodeller / From modelling to dimensioning : To modify production models to analysis models

Barikan, Mohammed, Ehsanzamir, Siavash January 2013 (has links)
Allt fler aktörer inom byggbranschen övergår från att använda gamla och traditionella verktyg i sin projektering till mer avancerade och moderna BIM-verktyg. Däremot sker denna utveckling långsamt på grund av skeptisk och konservativt inställning i byggbranschen. Idag finns analysprogram som har förmågan att beräkna och analysera komplexa strukturer, men trots detta är det väldigt vanligt med handberäkningar. I branschen börjar modellering av produktionsmodeller i moderna 3D BIM-verktyg få fotfäste. Det är praktiskt möjligt att modifiera en produktionsmodell till en analysmodell för att sedan beräknas i ett analysverktyg och det är detta som kommer bland annat undersökas. I denna rapport utreds även skillnaderna mellan handberäkningar och beräkningar i analysverktyg samt undersöks lönsamheten i en arbetsmetod där produktionsmodell och analysmodell integreras. Målet med denna rapport var att skapa ett tillvägagångssätt för en  fungerande överföring mellan produktionsmodell och analysmodell. Vilket enligt denna undersökning resulterar i en effektivare och lönsammare projektering. / Many businesses operating in the construction industry are nowadays substituting traditional tools in their project designing process with more modern and advanced BIM tools. However, this transition is taking place at a rather languid pace due to a skeptical and conservative attitude in the construction industry. Today, analysis software that has the ability to calculate and analyze complex structures is available. Yet, despite of this fact, manual calculations are still very common. The use of modern 3D-BIM tools has just started to gain a foothold, and a slight increase in both use and popularity in the construction branch. It is virtually possible to modify a production model into an analysis model using this technology, and that is one of the many aspects that will be investigated in this report. The differences between manual calculation and calculations made with analysis tools will be outlined, as well as the profitability of working with a production model where an analysis model has been integrated. The main objective of the following study was to provide a functioning approach for the effective transfer from a production model to an analysis model, which this investigation have eventuated to a more efficient and profitable project.
37

Revisorns oberoende : En kvalitativ uppsats om relationen mellan revisorer på mindre revisionsbyråer och deras klientföretag / Auditor independence : A qualitative thesis about the relationship between auditors in smaller accounting firms and their client companies

Nilsson, Moa, Mårtensson, Cornelia January 2023 (has links)
Bakgrund och problemdiskussion: Flertalet internationella och nationella kriser har skakat om revisionsvärlden till följd av att revisorn inte alltid har agerat oberoende. En betydande faktor som kan påverka revisorns oberoende är relationen mellan revisorn och klientföretaget. Utifrån tidigare forskning finns det ett behov av att studera revisorns oberoende på mindre revisionsbyråer genom att titta på relationen ur både revisorns och klientföretagets perspektiv. För att skapa en djupare förståelse för relationen kommer den sociala identitetsteorin att användas. Teorin innebär att en gemensam identiteten kan uppstå till följd av att revisorn och klientföretaget spelar inom samma sociala kontext. Syfte: Syftet med uppsatsen är att bidra till en fördjupad förståelse för revisorns oberoende, med ett särskilt fokus på relationen mellan revisorer på mindre revisionsbyråer och deras klientföretag. Metod: Uppsatsen utgår från en deduktiv forskningsansats och en kvalitativ forskningsstrategi. Semistrukturerade intervjuer har använts för att samla in uppsatsens empiriska material där komparativ design har använts som forskningsdesign. Analysen av det empiriska materialet har utgått från en tematisk analys. Slutsats: Uppsatsen visar på att klientföretagen har andra förväntningar på revisorn än vad revisorn möjligen kan prestera. Dessutom utför revisorer uppgifter som kan stå i strid med analysmodellen. Revisorn och klientföretaget kan identifiera sig med varandra eftersom de befinner sig i samma sociala kontext. Relationen mellan revisorn och klientföretaget kan ses vara mer komplex än vad man tänker sig, varför revisorns oberoende ibland kan ifrågasättas till följd av relationen. / Background and problem discussion: Several international and national crises have shaken the audit world because of the auditor not always acting independent. A significant factor that may affect the auditor's independence is the relation between the auditor and the client company. Based on previous research, there is a need to study the auditor’s independence at smaller accounting firms by looking at the relation from the perspective of both the auditor and the client company. To create a deeper understanding of the relation, the social identity theory will be used. The theory means that a common identity can arise because of the auditor and the client company playing within the same social context. Purpose: The purpose of this thesis is to contribute to a deeper understanding of auditor independence, with a particular focus on the relationship between auditors at smaller audit firms and their client companies. Method: This thesis is based on deductive research approach and a qualitative research strategy. Semi-structured interviews have been used to collect the thesis’s empirical material where comparative design has been used as research design. The analysis of the empirical material has been based on a thematic analysis. Conclusion: This thesis shows that the client companies have different expectations of the auditor than what the auditor can perform. In addition, the auditors perform tasks that may conflict the analysis model. The auditor and the client company can identify with each other because they are in the same social context. The relationship between the auditor and the client company can be seen as more complex than imagined, which is why the auditor's independence can sometimes be questioned because of the relationship.
38

Den grafiska linjen : En analysmetod för produktion av elektronisk dansmusik

Salomaa, Max January 2024 (has links)
Detta är ett konstnärligt examensarbete där jag utforskar den grafiska linjen, en kvalitativ analysmetod som kartlägger musikens struktur, instrumentering, arrangemang och ljuddesign i en DAW. Arbetet utförs genom en kombination av musikproduktion, analys och teoretisk undersökning. Med fokus på elektronisk dansmusik (EDM) och dess snabba utveckling inom populärkulturen, analyserar jag tre EDM-låtar med den grafiska linjen i Ableton Live och skapar tre nya låtar baserade på dessa analyser. Syftet är att främja musikalisk praxis genom att identifiera viktiga processer och händelser i musiken samt att skapa verktyg för musikproduktion. Den grafiska linjen är en metod som har sitt ursprung i mitt behov att upptäcka mönster i den musik jag arbetar med. Genom denna forskning har jag kunnat artikulera min arbetsprocess och mina insikter i användningen av musikaliska mallar. För att fördjupa förståelsen av den grafiska linjens tillämpning inom EDM har jag integrerat tidigare forskning om tonalitet, rytm och andra musikaliska aspekter inom genren. Denna forskning bidrar till studien av elektronisk dansmusik och ger perspektiv på användningen av den grafiska linjen som ett verktyg för musikalisk utforskning och skapande. / In this artistic thesis project, I explore the graphic line, a qualitative analysis method that maps the structure, instrumentation, arrangement, and sound design of music in a DAW through a combination of music production, analysis, and theoretical inquiry. By focusing on electronic dance music (EDM) and its rapid evolution within popular culture, I analyzed three EDM tracks using the graphic line in Ableton Live and created three new tracks based on these analyses. The aim is to promote musical practice by identifying key processes and events in music and creating tools for music production. The graphic line is a method that originates from my need to discover patterns in the music I work with. Through this research, I have been able to articulate my workflow and insights into the use of musical templates. To deepen understanding of the graphic line's application within EDM, I have integrated previous research on tonality, rhythm, and other musical aspects within the genre. This research contributes to the study of electronic dance music and provides perspectives on the use of the graphic line as a tool for musical exploration and creation.
39

META-ANALYSIS OF GENE EXPRESSION STUDIES

Siangphoe, Umaporn 01 January 2015 (has links)
Combining effect sizes from individual studies using random-effects models are commonly applied in high-dimensional gene expression data. However, unknown study heterogeneity can arise from inconsistency of sample qualities and experimental conditions. High heterogeneity of effect sizes can reduce statistical power of the models. We proposed two new methods for random effects estimation and measurements for model variation and strength of the study heterogeneity. We then developed a statistical technique to test for significance of random effects and identify heterogeneous genes. We also proposed another meta-analytic approach that incorporates informative weights in the random effects meta-analysis models. We compared the proposed methods with the standard and existing meta-analytic techniques in the classical and Bayesian frameworks. We demonstrate our results through a series of simulations and application in gene expression neurodegenerative diseases.
40

Da participação à voz: um estudo polifônico das atas do Conselho Estadual de Política Cultural (CONSEC) à luz do Modelo de Análise Modular do Discurso

FERNANDES, Wagner Adriano 29 July 2016 (has links)
Este estudo parte da hipótese de que, mesmo em setores de gestão pública, é possível haver privilégios de alguns segmentos em detrimento de outros, comprometendo o direito igualitário e democrático da participação. Com base nessa hipótese, nosso objetivo é compreender como se dá a dinâmica da participação dos conselheiros que representam diferentes segmentos sociais dentro do conselho de política cultural de Minas Gerais (CONSEC) e o processo de efetivação de suas vozes por meio de registros oficiais. Para alcançar esse objetivo, será apresentada, de forma sistemática, a análise de seis atas de reuniões do conselho de política cultural de Minas Gerais (CONSEC), com base em contribuições teóricas e metodológicas de um modelo de análise discursiva, o Modelo de Análise Modular do Discurso. Nesta pesquisa, esse modelo permitiu uma análise sob o ponto de vista dos módulos interacional, sintático, referencial e hierárquico, bem como da forma de organização elementar enunciativa e da forma de organização complexa polifônica. Como resultados, verificamos que, de acordo com os registros nas atas, não há igualdade participativa entre os segmentos do CONSEC, fato que compromete a função democrática desse conselho. / This study starts from the assumption that, even in public administration sectors, there may be some segments privileges over others, jeopardizing the egalitarian and democratic right of participation. Based on this assumption, our goal is to understand how is the dynamic participation of the directors representing such segments within the cultural policy of the board of Minas Gerais (CONSEC) and the process of realization of their voices though official records. To achieve this goal, will be presented in a systematic way, the analysis of six minutes of meetings of cultural policy council Minas Gerais (COSEC), based on theoretical and methodological contributions of a discourse analysis model, the Modular Analysis Model Discourse. In this research, this model allowed na analysis from the perpective of interactional modules, syntactic, and hierarchical framework, as well as the form of enunciation elementar organization and from of polyphonic complex organization. As a result, we find that, according to the records in the minutes, there is no participatory equality between segments CONSEC, a fact that undermines the democratic function of this council.

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