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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.
1

A Meta-Model for the Dialog Flow Notation

Book, Matthias, Gruhn, Volker 03 December 2018 (has links)
While the separation of presentation and application logic is widely practiced in web-based applications today, many do not cleanly separate application and dialog control logic, which leads to inflexible implementations especially when multiple presentation channels shall be served by the same application logic. We therefore present a notation for specifying the complete dialog flow of an application separately from the application logic and show how to construct a formal metamodel for it using the OMG’s Meta-Object Facility (MOF). This allows the validation of dialog flow models, as well as the generation of machine-readable dialog flow specifications from graphical models.
2

Examining the Impact of Experimental Design Strategies on the Predictive Accuracy of Quantile Regression Metamodels for Computer Simulations of Manufacturing Systems

January 2016 (has links)
abstract: This thesis explores the impact of different experimental design strategies for the development of quantile regression based metamodels of computer simulations. In this research, the objective is to compare the resulting predictive accuracy of five experimental design strategies, each of which is used to develop metamodels of a computer simulation of a semiconductor manufacturing facility. The five examined experimental design strategies include two traditional experimental design strategies, sphere packing and I-optimal, along with three hybrid design strategies, which were developed for this research and combine desirable properties from each of the more traditional approaches. The three hybrid design strategies are: arbitrary, centroid clustering, and clustering hybrid. Each of these strategies is analyzed and compared based on common experimental design space, which includes the investigation of four densities of design point placements three different experimental regions to predict four different percentiles from the cycle time distribution of a semiconductor manufacturing facility. Results confirm that the predictive accuracy of quantile regression metamodels depends on both the location and density of the design points placed in the experimental region. They also show that the sphere packing design strategy has the best overall performance in terms of predictive accuracy. However, the centroid clustering hybrid design strategy, developed for this research, has the best predictive accuracy for cases in which only a small number of simulation resources are available from which to develop a quantile regression metamodel. / Dissertation/Thesis / Masters Thesis Engineering 2016
3

A formulation for efficient adaptive metamodelling in engineering design

Makin, Thomas January 2014 (has links)
This thesis presents the research and development of robust metamodelling tools for engineering design. Metamodelling in engineering is typically used for reducing computational cost of highly expensive analyses or simulations. Metamodels have been shown to be effective in these problems where an approximation constructed from a limited set of true data points is used in support of optimisation. The inspiration for this work is drawn from the optimisation of aircraft wing structures, constructed using large numbers of rectangular stiffened panels. When optimising such structures to produce a minimum weight design, it is necessary to evaluate multiple design constraints such as buckling load, damage tolerance and repairability. The total computational cost for this aspect of the analysis can become considerable when a large number of evaluations is required and can creates a bottleneck in the optimisation workflow. In response to this industrial design problem, a specification is proposed for an efficient and adaptive metamodelling formulation. Following an extensive literature review the multilevel Radial Basis Function (mRBF) model is highlighted as a promising candidate for further investigation. The mRBF formulation is discussed in detail, and a comparative study is presented comparing mRBF to more established modelling techniques. mRBF is then put to work on a range of optimisation test problems, including an industrial scale multi-panel wing design scenario. Emphasis is placed on the adaptive acquisition of model data as the optimisation process progresses. Implementation details and software development processes are also presented in detail. The case is made for decoupled modelling workflows, and a RESTful web based mRBF modelling framework. Finally the performance of the proposed modelling scheme is compared to the original specification, and recommendations are made for further investigation.
4

Innovative and Efficient Simulation-Optimization Tools for Successful Groundwater Management and Conflict Resolution

Timani, Bassel 01 May 2015 (has links)
Decision makers' conflicts about the validity of a single simulation model and inefficiencies of existing response matrix methods (RMM) hinder adopting successful groundwater management plans. We speed up the process by proposing a hybrid RMM that is most efficient for situations in which optimizable stimuli can vary through consecutive periods of uniform duration interspersed with periods of different duration. We use the hybrid RMM within Simulation-Optimization (S-O) models to develop optimal water management strategies. For the tested problems, the hybrid RMM requires as much or 63-89% less computation time than other RMMs. Second, we propose Multi-Conceptual Model Optimization (MCMO) that can help stakeholders reach a compromise strategy instead of agreeing on the validity of a single model. MCMO computes optimal strategies that simultaneously satisfy analogous constraints and bounds in multiple numerical models differing by more than parameter values. Applying MCMO to Cache Valley (Utah, USA) reveals that protecting local ecosystem limits the increased groundwater pumping to satisfy only 40% of projected water demand increase using two models. To successfully and sustainably manage Cache Valley aquifer, we evaluate sustained yield strategies (SYS) and quantify the resilience of a computed SYS. We maximize the number of new residents who can have their indoor and outdoor uses satisfied, subject to constraints on aquifer-surface waters conditions, and limiting new residents to projected increases in population (PIiP). furthermore, we examine the effect of optimization approach and sequiencing, temporally-lagged spatially distributed return flow that is a function of optimal groundwater use, and the acceptability time evaluation on the optimal yield strategy. Cache Valley aquifer can sustainably satisfy the outdoor water demand of 74%-83% and the indoor water demand of 83%-100% of the PIiP. We quantify deterministic resilience Rd(A,T,SV)=P to evaluate how completely an aquifer condition (SV) recovers after the end of climatic anomaly (A), by recovery time (T). Simulation predicts that Cache Valley aquifer system resiliences to a 2-year drought are Rd(2YD, 3 yrs, Overall) = 93% and Rd (2YD,≥8,Overall) ≥ 95%. Proportionally reducing pumping rates by 25% through the time horizon of the simulation increases the overall resilience to 96% within 3 years.
5

Supporting Integration Activities in Object-Oriented Applications

Uquillas-Gomez, Verónica 10 October 2012 (has links) (PDF)
De plus en plus de logiciels sont développés par des équipes de développeurs travaillant de manière collaborative en parallèle. Les développeurs peuvent altérer un ensemble d'artéfacts, inspecter et in- tégrer le code de changements faits par d'autres développeurs. Par exemple, les corrections d'erreurs, les améliorations ou nouvelles fonctionnalités doivent être intégrées dans la version finale d'un logi- ciel et ceci à différents moments du cycle de développement. A un niveau technique, le processus de développement collaboratif est mis en pratique à l'aide d'outils de contrôle de versions (ex: git, SVN). Ces outils permettent aux développeurs de créer leurs propres branches de développement, faisant des tâches de fusion ou d'intégration de ces branches une partie intégrante du processus de développement. Les systèmes de versions de contrôle utilisent des algorithmes de fusion pour aider les développeurs à fusionner les modifications de leur branche dans le base de code commune. Cependant ces techniques travaillent à un niveau lexical, et elles ne garantissent pas que le système résultant soit fonctionnel. Alors que l'utilisation de branches offre de nombreux avantages, la fusion et l'intégration de mod- ifications d'une branche sur une autre est difficile à mettre en oeuvre du fait du manque de support pour assister les développeurs dans la compréhension d'un changement et de son impact. Par exemple, l'intégration d'un changement peut parfois avoir un effet inattendu sur le système et son comporte- ment menant à des bugs subtiles. De plus, les développeurs ne sont pas aidés lors de l'évaluation de l'impact d'un changement, ou lors de la sélection de changements à intégrer d'une branche vers une autre (cherry picking), en particulier lorsque ces branches ont divergé. Dans cette dissertation, nous présentons une approche dont le but est d'apporter des solutions à ces problèmes pour les développeurs, et plus précisément les intégrateurs. Cette approche se base sur des outils et solutions semi-automatisés aidant à de changements la compréhension à l'intérieur d'une branche ou entre branches. Nous nous attachons à satisfaire les besoins en information des intégrateurs quand ils doivent comprendre et intégrer des changements. Pour cela, nous caractérisons les changements et/ou séquences de changements et leurs dépendances. Ces caractérisations sont basées sur la représentation comme citoyens de première classe de l'historique du système et des changements approtés considérant les entités logicielles (ex: classes ou méthodes) et leurs relations plutôt que des fichiers et du texte comme le font les outils de con- trôle de versions. Pour cela, nous proposons une famille de méta-modèles (Ring, RingH, RingS et RingC) qui offrent une représentation des entités du système, de son historique, des changements apportés dans les différentes branches et de leurs dépendances. Des instances de ces meta-modèles sont ensuite utilisées par nos outils destinée à assister les intégrateurs: Torch, un outil visuel qui car- actérise les changements, et JET un ensemble d'outils qui permettent de naviguer dans des séquences de changements. Mots clés: programmation à objets; méta-modèles; historique et versions de programmes; vi- sualisation de programmes; fusion sémantique; analyse de programmes. Samenvatting Hedendaagse software is het resultaat van een collaboratief ontwikkelingsproces met meerdere teams van ontwikkelaars. Het doel van dit proces is om het toe te laten dat ontwikkelaars gelijktijdig en onafhankelijk van elkaar kunnen werken. Hiervoor hebben ze toegang tot een gedeelde verzameling van artefacten die ze kunnen aanpassen, en hebben ze de mogelijkheid om de aanpassingen die an- dere ontwikkelaars maken aan de broncode te inspecteren en te integreren. Zo kunnen bijvoorbeeld bug fixes, verbeteringen en nieuwe functionaliteit tijdig geïntegreerd worden in een versie van een softwaresysteem. Op een technisch niveau wordt dit collaboratief ontwikkelingsproces ondersteund door versiecon- trolesystemen. Gezien deze versiecontrolesystemen het mogelijk maken voor ontwikkelaars om in hun eigen branch van het systeem te werken, zijn merging en integratie een volwaardig onderdeel van het ontwikkelingsproces geworden. Hiertoe bieden deze versiecontrolesystemen geavanceerde en geautomatiseerde merge-technieken aan die ontwikkelaars helpen om hun aanpassingen samen te voegen met de aanpassingen van andere ontwikkelaars. Echter, deze technieken garanderen niet dat het resultaat van dit samenvoegen tot een werkend systeem zal leiden. Alhoewel het gebruik van branching binnen het ontwikkelingsproces vele voordelen biedt, wor- den de hieraan verbonden taken van het invoegen en integreren van aanpassingen bemoeilijkt door een gebrek aan ondersteuning. Bijvoorbeeld, het integreren van aanpassingen kan een onverwachte impact hebben op het ontwerp of het gedrag van het systeem, wat dan weer kan leiden tot de intro- ductie van subtiele fouten. Bovendien wordt er aan ontwikkelaars geen ondersteuning geboden bij het integreren van veranderen die afkomstig zijn uit een andere branch van het systeem (het zogenaamde cherry picking), bij divergerende branches, bij het zoeken naar afhankelijkheden tussen aanpassingen, of bij het inschatten van de mogelijke impact van een verzameling veranderingen op het systeem. In dit proefschrift stellen we een techniek voor die bovenvermelde problemen aanpakt door on- twikkelaars - en in het bijzonder integrators - semi-automatisch te assisteren bij het integreren van aanpassingen, zowel binnen één branch als tussen verschillende branches. We leggen hierbij de klem- toon op het helpen van integrators om de informatie te verkrijgen die ze nodig hebben om aanpassin- gen aan de software te begrijpen en te integreren. Hiervoor maken we gebruik van een karakterisering van aanpassingen en van aanpassingsstromen (dit zijn een opeenvolging van aanpassingen binnen een branch), te samen met een karakterisatie van de afhankelijkheden tussen de aanpassingen. Deze karakteriseringen zijn gebaseerd op een eersterangs voorstelling van de historiek van een systeem en de aanpassingen die binnen deze historiek werden uitgevoerd. Deze voorstelling is gedefinieerd in termen van de feitelijke programma-entiteiten, in plaats van bestanden en tekst die integrators niet de noodzakelijke informatie verschaffen. Hiervoor bieden we een familie van meta- modellen aan (Ring, RingH, RingS en RingC) die een implementatie verschaffen van de voorstelling van programma-entiteiten, de historiek van het systeem, aanpassingen, en de afhankelijkheden tussen aanpassingen. Deze meta-modellen bieden ook de analyses aan om versies van een systeem te vergeli- jken, en om aanpassingen en afhankelijkheden te berekenen. Verder stellen we tools voor die, gebruik makende van instanties van onze meta-modellen, het mogelijk maken voor integrators om de karak-iv teriseringen van aanpassingen te analyseren. De visuele tool Torch en de verzameling van JET-tools, voorzien in de informatie die noodzakelijk is om assistentie te bieden bij respectievelijk het integreren van aanpassingen binnen één branch en tussen verschillende branches. Trefwoorden: objectgericht programmeren; meta-modellen; historiek en versies van pro- gramma's; visualisatie; semantisch mergen; programma-analyses
6

The Process of Metathinking in the Area of Information Systems Design

Nero, Eva January 2000 (has links)
<p>In the area of information systems design it is important to select an appropriate methodology in order to get an information system that functions as expected. The perspective behind the methodology is seldom stated explicitly. The epistemology that a methodology is based on has impacts on the design of the system. Therefore, the process of selecting an appropriate methodology is important. The aim of this work is to study how the process of metamodelling or metathinking is considered in the area of information systems design.</p><p>Interviews and a study of the literature have been performed in order to investigate the awareness of metamodelling thinking in the area of information systems design.In the literature we found that only a small part dealt with the process of metamodelling. The method engineering (ME) approach was found as a way of thinking that seems to consider metamodelling thinking. We have evaluated ME according to a synthesis of the works by van Gigch, Churchman, and Flood and Carson. The evaluation has shown that ME deals with metamodelling thinking. In order to improve the metamodelling thinking in ME, it is important to explicitly define how ME considers the aspect of participation of motivated actors and the iterative process. The interviews have shown that information systems designers use some kind of metamodelling thinking, but they do not seem to be aware of the process.</p><p>In an information system design process, it is important to shift perspectives from reality to modelling, and to the metamodelling level, in order to apply metamodelling thinking. Further work should be performed with the purpose of making the information systems designers aware of the importance of applying metamodelling thinking.</p>
7

The Process of Metathinking in the Area of Information Systems Design

Nero, Eva January 2000 (has links)
In the area of information systems design it is important to select an appropriate methodology in order to get an information system that functions as expected. The perspective behind the methodology is seldom stated explicitly. The epistemology that a methodology is based on has impacts on the design of the system. Therefore, the process of selecting an appropriate methodology is important. The aim of this work is to study how the process of metamodelling or metathinking is considered in the area of information systems design. Interviews and a study of the literature have been performed in order to investigate the awareness of metamodelling thinking in the area of information systems design.In the literature we found that only a small part dealt with the process of metamodelling. The method engineering (ME) approach was found as a way of thinking that seems to consider metamodelling thinking. We have evaluated ME according to a synthesis of the works by van Gigch, Churchman, and Flood and Carson. The evaluation has shown that ME deals with metamodelling thinking. In order to improve the metamodelling thinking in ME, it is important to explicitly define how ME considers the aspect of participation of motivated actors and the iterative process. The interviews have shown that information systems designers use some kind of metamodelling thinking, but they do not seem to be aware of the process. In an information system design process, it is important to shift perspectives from reality to modelling, and to the metamodelling level, in order to apply metamodelling thinking. Further work should be performed with the purpose of making the information systems designers aware of the importance of applying metamodelling thinking.
8

Modelling EU DIRECTIVE 2016/680 using Enterprise Architecture

Palmér, Charlie January 2017 (has links)
This master thesis attempted to create an enterprise architecture tool implementationof the new EU legislation General Data Protection Regulation. Using the archimatestandard as well as the tool EAAT (Enterprise Architecture Analysis Tool) changes havebeen proposed so that compliance with the legislation can be veried. 19 of the legislationsarticles are discussed and implemented with another eight discussed why they are notimplemented. Each implemented article is followed by a model snapshot as well as somepseudo-code for easier implementation independent of the tool used. Due to unforeseenproblems, no working implementation was not created but the proposed changes can bemade to t any tool built on Archimate's standard. Finally the proposed modication isdiscussed and future work related to modelling of the General Data Protection Regulationis proposed. / Detta examensarbete försökte skapa en implementation för enterprisearkitektursprogramav den nya EU-lagen Allmän Uppgiftsskyddsförordning. Genom att användaArchimates standard tillsammans med verktyget EAAT (Enterprise Architecture AnalysisTool) har förslag om modifikationer lagts fram så att foglighet med lagen kan testas. 19 avlagens artiklar diskuteras och har implementerats med åtta andra diskuterade varför de inteär implementerade. Varje implementerad artikel följs upp av en modell-bild samt pseudokodför att underlätta implementationer i andra verktyg. På grund av oförutsedda problemhar ingen fungerande implementation gjorts men the föreslagna modifikationerna kan implementerasi andra verktyg som desginats med Archimates standard i åtanke. Slutligendiskuteras de föreslagna modifikationerna och framtida arbeten relaterade till modelleringav den Allmänna Uppgiftsskyddsförordningen har lagts fram.
9

Performance evaluation of metamodelling methods for engineering problems: towards a practitioner guide

Kianifar, Mohammed R., Campean, Felician 29 July 2019 (has links)
Yes / Metamodelling or surrogate modelling techniques are frequently used across the engineering disciplines in conjunction with expensive simulation models or physical experiments. With the proliferation of metamodeling techniques developed to provide enhanced performance for specific problems, and the wide availability of a diverse choice of tools in engineering software packages, the engineering task of selecting a robust metamodeling technique for practical problems is still a challenge. This research introduces a framework for describing the typology of engineering problems, in terms of dimensionality and complexity, and the modelling conditions, reflecting the noisiness of the signals and the affordability of sample sizes, and on this basis presents a systematic evaluation of the performance of frequently used metamodeling techniques. A set of metamodeling techniques, selected based on their reported use for engineering problems (i.e. Polynomial, Radial Basis Function, and Kriging), were systematically evaluated in terms of accuracy and robustness against a carefully assembled set of 18 test functions covering different types of problems, sampling conditions and noise conditions. A set of four real-world engineering case studies covering both computer simulation and physical experiments were also analysed as validation tests for the proposed guidelines. The main conclusions drawn from the study are that Kriging model with Matérn 5/2 correlation function performs consistently well across different problem types with smooth (i.e. not noisy) data, while Kriging model with Matérn 3/2 correlation function provides robust performance under noisy conditions, except for the very high noise conditions, where the Kriging model with nugget appears to provide better models. These results provide engineering practitioners with a guide for the choice of a metamodeling technique for problem types and modelling conditions represented in the study, whereas the evaluation framework and benchmarking problems set will be useful for researchers conducting similar studies.
10

Multi-Physics Engine Simulation Framework for Drive Cycle Emissions Prediction. Development and Validation of a Framework for Transient Drive Cycle NOx Prediction Modelling based on Combining 1-D and 0-D Internal Combustion Engine Simulation and Statistical Meta-Modelling

Korsunovs, Aleksandrs January 2019 (has links)
The full text will be available at the end of the embargo period: 4th Aug 2025

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