Dissertations / Theses on the topic 'Change propagation'
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Giffin, Monica L. (Monica Lee). "Change propagation in large technical systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42351.
Full textIncludes bibliographical references (p. 76-77).
Propagation of engineering changes has gained increasing scrutiny as the complexity and scale of engineered systems has increased. Over the past decade academic interest has risen, yielding some small-scale in-depth studies, as well as a variety of tools aimed at aiding investigation, analysis and prediction of change propagation. This thesis applies many of the methods and seeks to apply and extend prior reasoning through examination of a large data set from industry, including data from more than 41,000 change requests (most technical, but others not) over nearly a decade. Different methods are used to analyze the data from a variety of perspectives, in both the technical and managerial realms, and the results are compared to each other and evaluated in the context of previous findings. Macro-level patterns emerge independent of smaller scale data patterns, and in many cases offer clear implications for technical management approaches for large, complex systems development.
by Monica L. Giffin.
S.M.
Pasqual, Michael C. "Multilayer network modeling of change propagation for engineering change management." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62481.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 141-143).
Engineering change management is a critical and challenging process within product development. One pervasive source of difficulty for this process is the phenomenon of change propagation, by which a change to one part or element of a design requires additional changes throughout the product. Research efforts to understand and manage change propagation have largely drawn on network analysis. This thesis builds upon past research by introducing a multilayer network model that incorporates three proposed layers, or domains, that contribute to change propagation: namely, the product layer, change layer, and social layer. Each layer contains a distinct network of nodes and intralayer edges, but also connects to the other two layers through inter-layer dependencies. The model facilitates extensive quantitative analysis of change propagation using a repository of single-layer, double-layer, and triple-layer tools and metrics. A case study of a large technical program, which managed over 41,000 change requests in eight years, is employed to demonstrate the practical utility of the model. Most significantly, the case study explores the program's social layer and discovers a real-world correspondence between an engineer's organizational role and the propagation effects of his or her work, as measured by the newly proposed Engineer Change Propagation Index (Engineer-CPI). The case study also reveals that parent-child propagation often spanned more than one, but never more than three, system interfaces, thus confirming the possibility of indirect propagation. Finally, the study finds that propagation always stopped after five, and rarely more than four, generations of descendants. In all, the multilayer network model's holistic approach has significant policy implications for engineering change management in industry.
by Michael C. Pasqual.
S.M.
S.M.in Technology and Policy
Keller, René. "Predicting change propagation : algorithms, representations, software tools." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443494.
Full textGonzalez, Marco A. "A new change propagation metric to assess software evolvability." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44607.
Full textCAFEO, BRUNO BARBIERI DE PONTES. "ON THE RELATIONSHIP BETWEEN FEATURE DEPENDENCIES AND CHANGE PROPAGATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26957@1.
Full textCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
PROGRAMA DE DOUTORADO SANDUÍCHE NO EXTERIOR
Características são abstrações-chave para o desenvolvimento e manutenção de linhas de produto de software. Um desafio encarado na manutenção de linhas de produto de software é o entendimento das dependências que existem entre características. No código-fonte, uma dependência entre características ocorre sempre que um elemento de programa dentro dos limites de implementação de uma característica depende de elementos externos a esta característica. Exemplos são atributos ou métodos definidos na implementação de uma característica, mas utilizados no código responsável pela implementação de outra característica. A medida que desenvolvedores modificam o código-fonte associado com uma característica, eles devem garantir que outras características são consistentemente atualizadas com as novas mudanças – as chamadas propagações de mudanças. No entanto, a apropriada propagação de mudanças não é uma tarefa trivial, pois características geralmente não são modularizadas no código-fonte. Dessa forma, dado uma mudança em uma determinada característica, é desafiador revelar quais (partes de) outras características também devem ser alteradas. Propagação de mudanças se torna, portanto, um aspecto central e não-trivial da manutenção de linhas de produto de software. Desenvolvedores podem negligenciar partes importantes de código que deveriam ser revisadas ou alteradas, portanto não propagando mudanças de forma completa. Por outro lado, desenvolvedores também podem analisar de forma desnecessária partes de código que não são relevantes para a tarefa de manutenção de características, portanto aumentando o esforço de manutenção ou até propagando mudanças de forma indevida. A criação de um bom modelo mental da estrutura das dependências de características se torna essencial para ganhar compreensão sobre o complexo relacionamento de características com o objetivo de propagar mudanças de forma apropriada. Infelizmente, não existe entendimento no estado-da-arte sobre propriedades estruturais de dependências de características que afetam a propagação de mudanças. Este entendimento ainda não é possível, pois: (i) não existe meios de caracterização e quantificação para propriedades estruturais de dependências de características, e (ii) não existem investigações empíricas sobre a influência dessas propriedades na propagação de mudanças. Nesse contexto, esta tese apresenta três contribuições para superar os problemas acima mencionados. Primeiro, foi desenvolvido um estudo para entender a propagação de mudanças na presença de dependência de características em várias linhas de produto industriais. Segundo, é proposto um arcabouço de medidas com o propósito de quantificar propriedades estruturais de dependências de características. Nesse contexto, também foi desenvolvido um estudo revelando que métricas convencionais tipicamente aplicadas em trabalhos de linha de produto, tais como a métrica de acoplamento, não são indicadores efetivos da propagação de mudanças em linhas de produto de software. As métricas propostas nesta tese superaram consistentemente as métricas convencionais estudadas. Terceiro, esta tese propõe um método para auxiliar a propagação de mudanças encarando informações sobre a organização de dependência de características encarando-as como um problema de agrupamento. Foi avaliado se a organização de informações proposta nesta tese tem potencial para auxiliar desenvolvedores a propagar mudanças em linhas de produto de software.
Features are the key abstraction to develop and maintain software product lines. A challenge faced in the maintenance of product lines is the understanding of the dependencies that exist between features. In the source code, a feature dependency occurs whenever program elements within the boundaries of a feature s implementation depend on elements external to that feature. Examples are either attributes or methods defined in the realisation of a feature, but used in the code realising other features. As developers modify the source code associated with a feature, they must ensure that other features are consistently updated with the new changes – the so-called change propagation. However, appropriate change propagation is far from being trivial as features are often not modularised in the source code. In this way, given a change in a certain feature, it is challenging to reveal which (part of) other features should also change. Change propagation becomes, therefore, a central and non-trivial aspect of software product-line maintenance. Developers may overlook important parts of the code that should be revised or changed, thus not fully propagating changes. Conversely, they may also unnecessarily analyse parts that are not relevant to the feature-maintenance task at hand, thereby increasing the maintenance effort or even mis-propagating changes. The creation of a good mental model based on the structure of feature dependencies becomes essential for gaining insight into the intricate relationship between features in order to properly propagate changes. Unfortunately, there is no understanding in the state of the art about structural properties of feature dependencies that affect change propagation. This understanding is not yet possible as: (i) there is no conceptual characterisation and quantification means for structural properties of feature dependency, and (ii) there is no empirical investigation on the influence of these properties on change propagation. In this context, this thesis presents three contributions to overcome the aforementioned problems. First, we develop a study to understand change propagation in presence of feature dependencies in several industry-strength product lines. Second, we propose a measurement framework intended to quantify structural properties of feature dependencies. We also develop a study revealing that conventional metrics typically used in previous research, such as coupling metrics, are not effective indicators of change propagation in software product lines. Our proposed metrics consistently outperformed conventional metrics. Third, we also propose a method to support change propagation by facing the organisation of feature dependency information as a clustering problem. We evaluate if our proposed organisation has potential to help developers to propagate changes in software product lines.
Garg, Tushar. "Estimating change propagation risk using TRLs and system architecture." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/110134.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 27-28).
Risk estimation is a key activity for product development and technology integration programs. There are a number of decision support tools that help project managers identify and mitigate risks in a project, however few explicitly consider the effects of architecture on risk. We propose a novel risk estimation framework that includes considerations of the system architecture. By starting with traditional project management literature, we define risk as a combination of likelihood and impact. We use Technology Readiness Levels as our measure for likelihood, and given that change propagates through interfaces, we used metrics that relate to connectivity to estimate impact. To analyze the connectivity, we model systems using networks of nodes and edges and calculate centrality metrics. This framework is applied to an industry example and we visualize the data in different formats to aid in analysis. The insights gained from this analysis are discussed, and we conclude that the risk estimation framework provides estimates that are in line with the experience of engineers at the company.
by Tushar Garg.
S.M. in Engineering and Management
Koh, Chan Yang Edwin. "Managing change propagation in the development of complex products." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609499.
Full textAriyo, Owolabi Opeyemi. "Change propagation in complex design : predicting detailed change cases with multi-levelled product models." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612492.
Full textSeifert, Mirko. "Designing Round-Trip Systems by Change Propagation and Model Partitioning." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-71098.
Full textHamraz, Bahram. "Engineering change modelling using a function-behaviour-structure scheme." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/245074.
Full textWeidlich, Matthias, Jan Mendling, and Mathias Weske. "Propagating Changes between Aligned Process Models." Elsevier, 2012. http://epub.wu.ac.at/3497/1/JSS12%2Dchange.pdf.
Full textImamura, Hisaji. "Network specific change in white matter integrity in mesial temporal lobe epilepsy." Kyoto University, 2017. http://hdl.handle.net/2433/226747.
Full textCarcillo, Magalie. "Etude des phénomènes liés à la propagation de flamme sur câble : instrumentation, formulation et modélisation." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS132.
Full textAssociated with a significant fire risk, electrical cables are subject to strict regulations in regard to their fire reaction. Standards were established to encourage cable manufacturers to produce fire-resistant cables with low toxic fumes. The electrical cables have to be classified according to the Euroclasses according to their performance in two standard fire tests: IEC 60332-1 (single cable test) and EN 50399 (large scale test on a cable ladder). The aims of the thesis were to analyze the main characteristic parameters of the cables governing their classification in the large scale test and to develop methods to predict this classification without having to carry out the test. Correlations were highlighted between the EN 50399 test and the characteristics of the cables but also between the EN 50399 test and small scale tests (IEC 60332-1 test and calorimeter cone). More than the correlations made between the fire tests, the influences of material parameters such as sheath thickness, the amount of isolation or the structure of the cables, were studied for the fire reaction of the cables during these three tests. As expected, the sheath plays a major role in protecting the internal fuels during the first moments of combustion. However, the non-flame retarded insulation eventually degrades, fueling the flame and intensifying the heat release rate. An analytical model was optimized during the thesis to predict the curve of the heat release rate for cables burning under the calorimeter cône, using the cable structure, test configuration and irradiance parameters. In addition, a numerical simulation of cone calorimeter tests has been proposed using finite element modeling. Complex geometry had to be implemented in order to properly predict the HRR curve of the cone. An analytical method wasn developed to predict the fire classification of electric cables from cone calorimeter results
Seifert, Mirko [Verfasser], Uwe [Akademischer Betreuer] Aßmann, and Jean [Akademischer Betreuer] Bézivin. "Designing Round-Trip Systems by Change Propagation and Model Partitioning / Mirko Seifert. Gutachter: Uwe Aßmann ; Jean Bézivin. Betreuer: Uwe Aßmann." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://d-nb.info/1067190163/34.
Full textMasmoudi, Mahmoud. "Contribution au développement d’une méthode analytique pour l’identification des dépendances et la propagation des changements d’ingénierie en re-conception de produits." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC021.
Full textEngineering Change Management, also known as Change Engineering, is the research domain that focuses on the study of changes and modifications brought by industrial designers on a product during one of the phases of its life cycle. These changes can exist in the case of product renewal for improvement or re-design. In the literature, several methods and tools have proposed to assess the change impact using the existing dependencies between the product components, predict effectively the change propagation and then evaluate its possible consequences. However, none of them attempted to characterize the dependency relationship in the form of a polynomial function in addition to the qualitative and quantitative values. Therefore, we propose, a new method to generate change variations, in order to model these variations in pairs with an analytical formula, expand the variations in pairs to changes in several variables and formally check the consistency of the results obtained. Visually, a dependency graph is constructed where nodes represent the components of product and edges are the functions that connect them. Our results show that this functional characterization of dependency allows an effective assessment of change propagation. A bike with 2-D geometric model is used to illustrate the proposed approach
Frommhold, Marvin, Sebastian Tramp, Natanael Arndt, and Niklas Petersen. "Publish and subscribe for RDF in enterprise value networks." Universität Leipzig, 2016. https://ul.qucosa.de/id/qucosa%3A15776.
Full textDam, Khanh Hoa, and s3007289@student rmit edu au. "Supporting Software Evolution in Agent Systems." RMIT University. Computer Science and Information Technology, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090319.143847.
Full textOgata, Sho. "Development of Coupled Thermal-Hydraulic-Mechanical-Chemical Models for Predicting Rock Permeability Change." Doctoral thesis, Kyoto University, 2019. http://hdl.handle.net/2433/244532.
Full text0048
新制・課程博士
博士(工学)
甲第22051号
工博第4632号
新制||工||1722(附属図書館)
京都大学大学院工学研究科都市社会工学専攻
(主査)教授 岸田 潔, 教授 木村 亮, 教授 小池 克明
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DFAM
Zhang, Xin. "Contribution à l’ingénierie du changement dans les projets de développement de produits : modèle de référence et simulation par système multi-agents." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14892/document.
Full textThe overall goal of this Ph.D. research is to provide reference models, support me- thods and tools that simulate change propagations in a Product Development (PD) project to assist decision-makings. We firstly establish a change analysis framework of modeling the context of change occurrence and propagation by taking into account the multiple knowledge areas of PD project simultaneously. Under the framework, we propose the conceptual models of change occurrence and change propagation that pro- vide a qualitative method to identify change and change propagation and imply some characteristics of change propagations. Relying on that, we suggest the procedures of building up the change propagation networks. Within the network, we propose the methodology of simulating change propagations and then present the process of im- plementing the methodologies and the models as a software prototype by using multi- agent based technology
Yin, Ruiqing. "Steps towards end-to-end neural speaker diarization." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS261/document.
Full textSpeaker diarization is the task of determining "who speaks when" in an audio stream that usually contains an unknown amount of speech from an unknown number of speakers. Speaker diarization systems are usually built as the combination of four main stages. First, non-speech regions such as silence, music, and noise are removed by Voice Activity Detection (VAD). Next, speech regions are split into speaker-homogeneous segments by Speaker Change Detection (SCD), later grouped according to the identity of the speaker thanks to unsupervised clustering approaches. Finally, speech turn boundaries and labels are (optionally) refined with a re-segmentation stage. In this thesis, we propose to address these four stages with neural network approaches. We first formulate both the initial segmentation (voice activity detection and speaker change detection) and the final re-segmentation as a set of sequence labeling problems and then address them with Bidirectional Long Short-Term Memory (Bi-LSTM) networks. In the speech turn clustering stage, we propose to use affinity propagation on top of neural speaker embeddings. Experiments on a broadcast TV dataset show that affinity propagation clustering is more suitable than hierarchical agglomerative clustering when applied to neural speaker embeddings. The LSTM-based segmentation and affinity propagation clustering are also combined and jointly optimized to form a speaker diarization pipeline. Compared to the pipeline with independently optimized modules, the new pipeline brings a significant improvement. In addition, we propose to improve the similarity matrix by bidirectional LSTM and then apply spectral clustering on top of the improved similarity matrix. The proposed system achieves state-of-the-art performance in the CALLHOME telephone conversation dataset. Finally, we formulate sequential clustering as a supervised sequence labeling task and address it with stacked RNNs. To better understand its behavior, the analysis is based on a proposed encoder-decoder architecture. Our proposed systems bring a significant improvement compared with traditional clustering methods on toy examples
Hassan, Ahmed. "Mining Software Repositories to Assist Developers and Support Managers." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/1017.
Full textRaddadi, Merfat. "Charge propagation in a classical background." Thesis, University of Plymouth, 2013. http://hdl.handle.net/10026.1/3134.
Full textJaiser, Ralf. "Dreidimensionale Diagnostik der großskaligen Zirkulation der Tropo- und Stratosphäre." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6906/.
Full textIn this study concepts for the diagnostics of the large-scale circulation in the troposphere and the stratosphere are developed. Therefore the energy budget, wave propagation and the interaction between waves and the mean flow are analyzed. A corresponding set of diagnostic methods is derived. Furthermore a new type of localized Eliassen Palm Fluxes including moisture fluxes is introduced. These diagnostic methods are then applied to the ERA-Interim reanalysis and to a run of the ECHAM6 atmospheric model forced with observed sea surface temperatures and sea ice data. The diagnostics of the large scale circulation are useful to enhance the understanding of the climate system dynamics. Furthermore the knowledge of the relation between energy sources and sinks, atmospheric waves on planetary and synoptic scales and their forcing of the mean flow is applicable to validate global climate models. The results presented here show small deviations in terms of the energy balance in ECHAM6 but large discrepancies in terms of wave propagation. On the one hand Eliassen Palm fluxes connected to planetary waves are generally too strong. On the other hand the mean flow forcing within upper tropospheric jet streams by synoptic scale waves does not agree with observations, since the vertical propagation is shifted. A second part of this study analyses the influence of Arctic sea ice anomalies at the sea ice minimum in August/September on atmospheric conditions. Strong positive temperature anomalies with their maximum at the surface are observed. In autumn they lead to intensified synoptic scale systems, because of a reduced atmospheric vertical stability. A large-scale barotropic circulation pattern up to the stratosphere appears in winter related to previous late summer sea ice changes. A reduced meridional pressure gradient leads to a pattern related to a negative phase of the Arctic Oscillation in the troposp here as well as related to a weaker stratospheric polar vortex. The same analysis performed with an ECHAM6 model run shows a too small warming of Arctic latitudes. While tropospheric changes in the Arctic are covered by the model to some degree, the stratosphere shows large discrepancies in reproducing the observed changes in the low ice period. The vertical propagation of planetary waves from the troposphere into the stratosphere is reproduced with large differences. Accordingly this study shows the largest errors in ECHAM6 related to atmospheric wave propagation.
Da, Silva João Bosco. "Charge en mouvement sur une fondation périodique." Ecully, Ecole centrale de Lyon, 1993. http://www.theses.fr/1993ECDL0042.
Full textRa, Youngchul 1968. "Laminar flame propagation in a stratified charge." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9341.
Full textIncludes bibliographical references (p. 48-50).
The propagation of laminar flame from a rich or stoichiometric mixture to a lean mixture in a stratified methane-air charge was investigated experimentally and numerically. Emphasis was on the understanding of the flame behavior in the transition region; in particular, on the mechanism of burning velocity enhancement in this region. In the experimental setup, mixtures of two different equivalence ratios were separated by a soap bubble in a spherical constant volume combustion vessel. The richer mixture inside the bubble was ignited by a focused laser beam. The flame development was observed by Schlieren technique and flame speeds were measured by heat release analysis of the pressure data. An one-dimensional, time-dependant numerical simulation of the flame propagation in a charge with step-stratification was used to interpret the experimental results. Both the experimental and numerical studies showed that the instantaneous flame speed depended on the previous flame history. Thus a 'strong'(with mixture equivalence ratio close to stoichiometric) flame can sustain propagation into finite regions of substantially lean equivalence ratio. Both thermal and chemical effects were crucial for explaining the mechanism of the flame speed enhancement in the transition period. Because of the presence of this 'back-support' effect, the usual concept of specifying the burning velocity as a function of the end gas state is inadequate for a stratified charge. A simple correlation for instantaneous flame velocity based on the local burned gas temperature is developed.
by Youngchul Ra.
Ph.D.
Wiese, Igor Scaliante. "Predição de mudanças conjuntas de artefatos de software com base em informações contextuais." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/45/45134/tde-02122016-140016/.
Full textCo-change prediction aims to make developers aware of which artifacts may change together with the artifact they are working on. In the past, researchers relied on structural analysis to build prediction models. More recently, hybrid approaches relying on historical information and textual analysis have been proposed. Despite the advances in the area, software developers still do not use these approaches widely, presumably because of the number of false recommendations. The hypothesis of this thesis is that contextual information of software changes collected from issues, developers\' communication, and commit metadata describe the circumstances and conditions under which a co-change occurs and this is useful to predict co-changes. The aim of this thesis is to use contextual information to build co-change prediction models improving the overall accuracy, especially decreasing the amount of false recommendations. We built predictive models specific for each pair of files using contextual information and the Random Forest machine learning algorithm. The approach was evaluated in 129 versions of 10 open source projects from the Apache Software Foundation. We compared our approach to a baseline model based on association rules, which is often used in the literature. We evaluated the performance of the prediction models, investigating the influence of data aggregation to build training and test sets, as well as the identification of the most relevant contextual information. The results indicate that models based on contextual information can correctly predict 88% of co-change instances, against 19% achieved by the association rules model. This indicates that models based on contextual information can be 3 times more accurate. Models created with contextual information collected in each software version were more accurate than models built from an arbitrary amount of contextual information collected from more than one version. The most important pieces of contextual information to build the prediction models were: number of lines of code added or modified, number of lines of code removed, code churn, number of words in the discussion and description of a task, number of comments, and role of developers in the discussion (measured by the closeness value obtained from the communication social network). We asked project developers about the relevance of the results obtained by the prediction models based on contextual information. According to them, the results can help new developers to the project, since these developers have no knowledge about the architecture and are usually not familiar with the artifacts history. Thus, our results indicate that prediction models based on the contextual information are useful to support developers during the maintenance and evolution activities
Zhang, Xin. "Contribution à l'ingénierie du changement dans les projets de développement de produits : modèle de référence et simulation par système multi-agents." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00920415.
Full textDamak, Youssef. "Operational Context-Based Design and Architecting of Autonomous Vehicles A semi-automated requirements reuse and recycling process for Autonomous Transportation Systems R&D." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASC029.
Full textAutonomous Vehicles (AV) are emerging systems and considered cornerstones of the future of mobility. Their design is a source of many academic and industrial research efforts. The industrialization of AV is the mean for mobility stakeholders to strengthen their future position. AVs function by interacting with their operational environment and must be fit for their Operational Context (OC). Adapting AVs architectures to their Operational Context during design becomes an important challenge in designing robust AV.The current state of the art does not propose AV architecting methods based on the OC. This research work aims to support the architecting activities of Autonomous Vehicles to result in architectures fit for their Operational Context. An OC ontology for AV is proposed to support scenario identification and definition in the early design phase, for a scenario-based design approach. Using this ontology, a method to design AV logical architecture based on the OC is proposed. The consideration of the OC in the architecting activities of AV is strengthened with a second method aiming at assessing the impact of OC change on the AV’s architecture during the design phase. The proposed contributions are validated with industrial case studies on the design of AV architectures given the OC and its evolution
Sørensen, Caroline S. M. Massachusetts Institute of Technology. "Measurement of flame propagation through step changes in mixture composition." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104265.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 51-53).
Flame speed is a central metric in the field of combustion. While particular mixtures have characteristic flame speeds, it has also been shown that in compositionally stratified mixtures, flames exhibit a path dependency, or memory effect. The goal of the experimental work presented in this thesis was to investigate the behavior of flame speed over step changes in equivalence ratios. This sharp stratification was achieved using a soap bubble blown at the center of a combustion bomb. A laser was used to ignite the mixture from the center. Flame speed was calculated from both a pressure trace analysis and from measuring the movement of the flame front through high speed Schlieren imaging. Both methods demonstrated good correlation with the literature for homogeneous charges. However, the analysis necessarily assumes a spherical flame, but the Schlieren video showed that the laser ignition system induced a significant protrusion in the flame front. This protrusion smooths the transition from the flame speed of the inner mixture to that of the outer. Therefore, it was demonstrated that this setup is not suitable for the measurement of flame speed transitional behavior over step-changes in equivalence ratio.
by Caroline Sorensen.
S.M.
Akour, Mohammed Abd Alwahab. "Towards Change Propagating Test Models In Autonomic and Adaptive Systems." Diss., North Dakota State University, 2012. https://hdl.handle.net/10365/26504.
Full textHustedt, Bernhard. "Propagation des ondes : approches espace et ondelette." Phd thesis, Université de Nice Sophia-Antipolis, 2002. http://tel.archives-ouvertes.fr/tel-00653799.
Full textMohan, Srividya. "Reaction coordinates for RNA conformational changes." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/33815.
Full textLemmens, Yves Claude Jean. "Modelling and analysis of engineering changes in complex systems." Thesis, Cranfield University, 2007. http://dspace.lib.cranfield.ac.uk/handle/1826/5071.
Full textDegefa, Tesfaye Hailu. ""Ion channel (mimetic) sensors" mechanism of charge propagation through thiol-, protein- and dendrimer-modified electrodes /." Doctoral thesis, [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=980218624.
Full textRobinson, Simon. "Charge Coupled Device camera recording and computational analysis of flame propagation in a spark-ignition engine." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/27203.
Full textMerhy, Elias. "Propagation de fissure sous chargement thermomécanique cyclique anisotherme." Phd thesis, Ecole Polytechnique X, 2011. http://pastel.archives-ouvertes.fr/pastel-00658854.
Full textEveillard, Sébastien. "Propagation d'une onde de choc en présence d'une barrière de protection." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-00952259.
Full textOuagne, Pierre. "Fracture property changes with oxidation and irradiation in nuclear graphites." Thesis, University of Bath, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341675.
Full textSjakste, Jelena. "Etude par propagation de paquets d'ondes de la dynamique du transfert électronique entre un atome et une surface métallique." Paris 11, 2004. https://tel.archives-ouvertes.fr/tel-00008743.
Full textThis PhD thesis is a theoretical and numerical study of the resonant charge transfer (RCT) process during a collision between an atom (ion) and a metal surface. The RCT corresponds to the transfer of an electron from the atom to the metal without an energy change. We study the RCT in systems with several localised states. These states can be localised on the projectile, or they can be localised on the projectile and an impurity of the surface. Special attention is paid to the projectile motion induced transitions between different states of the system. The Wave Packet Propagation Method, which consists in on the grid solution of the time-dependent Schrödinger equation, is used in this work. First, we study the local perturbation of the RCT between a projectile (H- ion) and a metal surface (Al or Cu(111)), induced by the presence on an alkali adsorbate (Li or Cs). Special attention is paid to the 3-body character of the RCT (the electron interacts with the projectile, the adsorbate and the substrate). The results for Cu(111), which has a projected band gap in the direction normal to the surface, are very different from the results for Al, which is a free-electron metal. Second, we study the RCT between Rydberg atoms (Xe) and a metal surface, in an external electric field. The collision-induced transitions between different states of the projectile strongly affect the RCT. Our results allow to understand the recent experimental results (group of F. B. Dunning, Houston, USA). This work shows the importance of an explicit study of the dynamics of RCT
SJAKSTE, Jelena. "Etude par propagation de paquets d'ondes de la dynamique du transfert électronique." Phd thesis, Université Paris Sud - Paris XI, 2004. http://tel.archives-ouvertes.fr/tel-00008743.
Full textAnache-Ménier, Domitille. "Propagation des ondes dans les milieux désordonnés: étude de la phase des ultrasons et des ondes sismiques." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00335480.
Full textLa théorie des distributions et des corrélations des dérivées spatiales et temporelles de la phase est développée dans l'hypothèse d'un champ scalaire analytique gaussien et circulaire. Ces fonctions statistiques permettent de caractériser les diffuseurs dans les deux dispositifs expérimentaux au coeur de cette thèse. D'une part, les fluctuations temporelles de la phase d'ultrasons sont utilisées pour sonder la dynamique d'une suspension de billes millimétriques sur des échelles de temps allant de la milliseconde à la seconde. D'autre part les fluctuations spatiales de la phase donnent une caractérisation de la diffusion multiple des ondes de flexion dans une plaque de Plexiglas ® perforée aléatoirement. Le comportement asymptotique en loi de puissance des distributions des dérivées de la phase démontre les propriétés gaussiennes des codas dans ces deux dispositifs.
Enfin, l'étude de la coda de séismes régionaux en Californie a permis de proposer une application à la détermination du libre parcours moyen des ondes sismiques dans la croûte terrestre : il est montré que c'est la seule échelle caractéristique de la fonction de corrélation de la dérivée spatiale de la phase.
Hayakawa, Naoki, Masato Morikawa, and Hitoshi Okubo. "Partial Discharge Inception and Propagation Characteristics of Magnet Wire for Inverter-fed Motor under Surge Voltage Application." IEEE, 2007. http://hdl.handle.net/2237/9459.
Full textBoerner, Susann. "Probing reaction conditions and cofactors of conformational prion protein changes underlying the autocatalytic self-propagation of different prion strains." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17003.
Full textPrions are the causative agent of transmissible spongiform encephalopathies in animals and humans such as scrapie, bovine spongiform encephalopathy (BSE) and Creutzfeldt-Jakob disease (CJD). Prions are thought to be composed essentially of a misfolded and aberrantly aggregated isoform of the cellular prion protein (PrP) and to replicate by seeded PrP polymerization. Prions may exist in the form of distinct strains that differ in their phenotypic characteristics although they are derived from the same cellular prion protein. Cofactor molecules other than PrP may be involved in prion replication and may be a determinant of strain properties. Furthermore, cofactors may also be required for conveying infectivity. The present study examined the effects of different cofactor molecules on the replication efficacy of four hamster adapted prion agents using the method of serial protein misfolding cyclic amplification (PMCA) as in vitro assay for PrP misfolding and aggregation. The study revealed strain dependent differences of PMCA conditions and cofactors required for efficient in vitro replication. The impact of cofactors was assessed by comparative analyses of selected biological, biochemical and biophysical properties of PMCA products (PrPres) and native prion seeds. The biological seeding activity as monitored in a primary hamster glial cell assay, and biochemical properties such as electrophoretic migration in SDS-gels, were affected differently by different cofactors. In order to define the impact of putative cofactors on the molecular conversion of PrP in more detail, changes in the spatial structure associated with different cofactor molecule conditions during amplification of PrPres in PMCA was monitored by Fourier transform-infrared (FT-IR) spectroscopic analysis. Largely preliminary data revealed spectral differences between native prion seeds and progeny PMCA generated PrPres for all prion strains, but no variations due to different cofactor conditions.
Fröhlich, Kristina, and Christoph Jacobi. "The solar cycle in the middle atmosphere: changes of the mean circulation and of propagation conditions for planetary waves." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 34 = Meteorologische Arbeiten aus Leipzig ; 9 (2004), S. 106-117, 2004. https://ul.qucosa.de/id/qucosa%3A15281.
Full textThe influence of the 11-year solar cycle on the zonal mean circulation was investigated with COMMA-LIM (Cologne Model of the Middle Atmosphere – Leipzig Institute for Meteorology), a 3-D mechanistical model. The solar impact was simulated via changes in solar absorption taking into account percentage contributions for different bands which are obtained from measurements. Additionally, new data sets for ozone were used. One combins the Berlin ozone climatology with new ozone data from GOME (Global Ozone Monitoring Experiment) and the other is produced by the chemical- transport model SUNY-SPB (State University New York – St. Petersburg) assimilating data from TOMS. Temperature differences between solar maximum and solar minimum conditions achieve up to 3 Kelvin in the stratosphere. Above 100 km the difference increases considerably, caused by the strong variation of absorption by molecular and atomic oxygen there. Changes in temperature distribution generate an increase of the mean westerly zonal wind in the winter mesosphere as well as an increase in the mean easterly zonal wind in the summer mesosphere in midlatitudes. It was investigated how strong the propagation of planetary waves is able to increase in the mean zonal wind during the solar cycle.
Lacombe, Céline. "Propagation des ondes élastiques dans la lithosphère hétérogène : modélisations et applications." Phd thesis, Grenoble 1, 2001. http://tel.archives-ouvertes.fr/tel-00759982.
Full textBaptista, Marcio. "Contribution à l'étude de la propagation de crues en hydrologie." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1990. http://pastel.archives-ouvertes.fr/pastel-00568722.
Full textBoullard, Arnaud. "Propagation des ondes dans les coques simples ou en nid d'abeilles soumises à des charges mobiles : application au lanceur Ariane 5." Châtenay-Malabry, Ecole centrale de Paris, 2004. http://www.theses.fr/2004ECAP0936.
Full textLefrancois, André. "Propagation par fatigue de fissures bi et tridimensionnelles dans deux alliages d'aluminium : effets de petite fissure et de chargements aleatoires." Paris, ENMP, 1987. http://www.theses.fr/1987ENMP0089.
Full textKriebel, Maximilian [Verfasser], Tim [Akademischer Betreuer] Clark, Tim [Gutachter] Clark, and Rainer [Gutachter] Fink. "1. Feynman-dispersion correction 2. Charge transport via imaginary time propagation / Maximilian Kriebel ; Gutachter: Tim Clark, Rainer Fink ; Betreuer: Tim Clark." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2020. http://d-nb.info/1211557510/34.
Full textDeberteix, Pascal. "Etude thermoaéraulique des écoulements en conduite ventilée en présence d'une source de chaleur : application à la propagation des fumées d'incendie en tunnel." Poitiers, 2000. http://www.theses.fr/2000POIT2268.
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