• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 145
  • 39
  • 29
  • 13
  • 6
  • 6
  • 6
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 294
  • 294
  • 141
  • 95
  • 88
  • 86
  • 78
  • 78
  • 66
  • 57
  • 48
  • 43
  • 40
  • 37
  • 32
  • 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.
181

Feature-based Software Asset Modeling With Domain Specific Kits

Altintas, Nesip Ilker 01 August 2007 (has links) (PDF)
This study proposes an industrialization model, Software Factory Automation, for establishing software product lines. Major contributions of this thesis are the conceptualization of Domain Specific Kits (DSKs) and a domain design model for software product lines based on DSKs. The concept of DSK has been inspired by the way other industries have been successfully realizing factory automation for decades. DSKs, as fundamental building blocks, have been deeply elaborated with their characteristic properties and with several examples. The constructed domain design model has two major activities: first, building the product line reference architecture using DSK abstraction / and second, constructing reusable asset model again based on DSK concept. Both activities depend on outputs of feature-oriented analysis of product line domain. The outcome of these coupled modeling activities is the reference architecture and asset model of the product line. The approach has been validated by constructing software product lines for two product families. The reusability of DSKs and software assets has also been discussed with examples. Finally, the constructed model has been evaluated in terms of quality improvements, and it has been compared with other software product line engineering approaches.
182

Multi-layer syntactical model transformation for model based systems engineering

Kwon, Ky-Sang 03 November 2011 (has links)
This dissertation develops a new model transformation approach that supports engineering model integration, which is essential to support contemporary interdisciplinary system design processes. We extend traditional model transformation, which has been primarily used for software engineering, to enable model-based systems engineering (MBSE) so that the model transformation can handle more general engineering models. We identify two issues that arise when applying the traditional model transformation to general engineering modeling domains. The first is instance data integration: the traditional model transformation theory does not deal with instance data, which is essential for executing engineering models in engineering tools. The second is syntactical inconsistency: various engineering tools represent engineering models in a proprietary syntax. However, the traditional model transformation cannot handle this syntactic diversity. In order to address these two issues, we propose a new multi-layer syntactical model transformation approach. For the instance integration issue, this approach generates model transformation rules for instance data from the result of a model transformation that is developed for user model integration, which is the normal purpose of traditional model transformation. For the syntactical inconsistency issue, we introduce the concept of the complete meta-model for defining how to represent a model syntactically as well as semantically. Our approach addresses the syntactical inconsistency issue by generating necessary complete meta-models using a special type of model transformation.
183

Methodology for the derivation of product behaviour in a Software Product Line

Istoan, Paul 21 February 2013 (has links) (PDF)
The major problem addressed in this thesis is the definition of a new SPLE methodology that covers both phases of the SPLE process and focuses on the derivation of behavioral models of SPL products. In Chapter 2 three research areas scope context of this thesis: Software Product Lines, Business Processes, and Model-Driven Engineering. Throughout Chapter 3, we propose a new SPLE methodology that focuses on the derivation of product behavior. We first describe the main flow of the methodology, and then detail the individual steps. In chapter 4 we propose a new domain specific language called CBPF created for modeling composable business process fragments. A model driven approach is followed for creating CBPF: definition of the abstract syntax, graphical concrete syntax and translational semantics. In Chapter 5 we propose several types of verifications that can be applied to business processfragments to determine their "correctness". For structural verification we definine a set of fragment consistency rules that should be valid for every business process fragment created with CBPF. To check behavioral correctness we first transform the business process fragment into an equivalent HCPN. We can then check generic properties but also define aset of fragment specific properties. In chapter 6 we exemplify the proposed SPL methodology by applying it to a case study from the crisis management system domain. We also propose a tool suite that supports our methodology. Chapter 7 describes possible improvements and extensions to the contributions of this thesis. We conclude the thesis in Chapter 8 and draw some conclusions.
184

Modeliais grįsto programų kūrimo metodo taikymas dokumentų valdymo sistemų kūrime / Using model driven development in the creation of document management systems

Vaitkevičius, Laurius 08 September 2009 (has links)
Modeliais grįstas programų kūrimas yra vienas naujausių abstrakcijos pakėlimo būdų programų kūrimo procese. Jis kai kuriais atvejais leidžia pagreitinti programų kūrimo procesą net iki 10 kartų. Šiame darbe analizuojamas dviejų modeliais grįstų metodų taikymas dokumentų valdymo sistemų kūrime – tai apibendrinta modeliais grįsta architektūra (MDA) ir dalykinei sričiai specifinis modeliavimas (DSM). Darbe rasite tiek teorinius šios temos aspektus, tiek ir praktinius bandymus. Teorinėje dalyje apibrėžta dokumentų valdymo sistema – jos pagrindinės funkcijos bei savybės. Taip pat išskirti pagrindiniai modeliais grįstų metodų privalumai ir trūkumai. Praktinių bandymų metu atsiskleidžia tikroji metodams skirtų palaikyti įrankių vertė. MDA įrankių atveju realiai pamatysite, kokios pagalbos galima laukti iš jų spartinant programų kūrimą. Tuo tarpu analizuojant DSM galimybes buvo sukurtas pilnai funkcionuojantis įrankis skirtas dokumentų valdymo sistemoms kurti, kuris leidžia sumodeliuoti dokumentų valdymo sistemų duomenų sluoksnį, sugeneruoti jo kodą bei duomenų bazių schemą. DSL kalbos kūrimo žingsnių aprašymas gali būti naudojamas kaip pagrindas kitų dalykinių sričių kalbų kūrimui, o sukurta kalba gali būti praplėsta iki tokio lygio, kokio reikia, ir naudojama dokumentų valdymo sistemų kūrime. / Model Driven Development is one of the newest ways to increase level of abstraction in software development process. In some cases it allows to increase productivity up to 10 times. This work analyzes usage of two model driven methods in the creation of document management systems. They are, unified Model Driven Architecture (MDA) and Domain Specific Modeling (DSM). You will find both, theoretical and practical aspects of this topic. Theoretical part consists of a definition of document management system, its functions and characteristics. It also contains main advantages and drawbacks of model driven methods. During practical experiments the real value of method supporting tools is revealed. In case of MDA tools, you will see what help can you expect while increasing productivity. Whereas while analyzing DSM possibilities the fully functional tool for modeling document systems was created. It allows creating a model of a data layer, generating its source code and database scheme. The description of DSL creation steps can be used as a base for other domains, and created language can be extended as much as needed and used to create document management systems.
185

CALV3 - Uma linguagem espec?fica de dom?nio para seguran?a em sistemas corporativos: um estudo de caso sistem?tico na ind?stria

Dantas, George Henrique Costa 06 August 2012 (has links)
Made available in DSpace on 2014-12-17T15:48:04Z (GMT). No. of bitstreams: 1 GeorgeHCD_DISSERT.pdf: 1498112 bytes, checksum: 47b708a57a0944475a3489af84029df2 (MD5) Previous issue date: 2012-08-06 / The academic community and software industry have shown, in recent years, substantial interest in approaches and technologies related to the area of model-driven development (MDD). At the same time, continues the relentless pursuit of industry for technologies to raise productivity and quality in the development of software products. This work aims to explore those two statements, through an experiment carried by using MDD technology and evaluation of its use on solving an actual problem under the security context of enterprise systems. By building and using a tool, a visual DSL denominated CALV3, inspired by the software factory approach: a synergy between software product line, domainspecific languages and MDD, we evaluate the gains in abstraction and productivity through a systematic case study conducted in a development team. The results and lessons learned from the evaluation of this tool within industry are the main contributions of this work / A comunidade acad?mica e a ind?stria de software t?m demonstrado, nos ?ltimos anos, bastante interesse em abordagens e tecnologias ligadas ? ?rea de desenvolvimento dirigido por modelos (MDD). Em paralelo a isto, continua a busca incessante da ind?stria por tecnologias que aumentem a produtividade e qualidade no desenvolvimento de produtos de software. Esta pesquisa visa explorar estas duas afirma??es, atrav?s de um trabalho que usa uma tecnologia MDD e avalia seu uso na resolu??o de um problema real no contexto de seguran?a de sistemas corporativos. Com a constru??o e uso de uma ferramenta, uma DSL visual denominada CALV3, inspirada na abordagem de F?bricas de Software: uma sinergia entre linha de produto de software, linguagens espec?ficas de dom?nio e MDD, avaliamos os ganhos em abstra??o e produtividade, atrav?s de um estudo de caso sistem?tico conduzido em uma equipe de desenvolvimento. Os resultados e li??es aprendidas com a avalia??o desta ferramenta no ?mbito industrial s?o uma das principais contribui??es deste trabalho
186

Automatic Optimization of Geometric Multigrid Methods using a DSL Approach

Vasista, Vinay V January 2017 (has links) (PDF)
Geometric Multigrid (GMG) methods are widely used in numerical analysis to accelerate the convergence of partial differential equations solvers using a hierarchy of grid discretizations. These solvers find plenty of applications in various fields in engineering and scientific domains, where solving PDEs is of fundamental importance. Using multigrid methods, the pace at which the solvers arrive at the solution can be improved at an algorithmic level. With the advance in modern computer architecture, solving problems with higher complexity and sizes is feasible - this is also the case with multigrid methods. However, since hardware support alone cannot achieve high performance in execution time, there is a need for good software that help programmers in doing so. Multiple grid sizes and recursive expression of multigrid cycles make the task of manual program optimization tedious and error-prone. A high-level language that aids domain experts to quickly express complex algorithms in a compact way using dedicated constructs for multigrid methods and with good optimization support is thus valuable. Typical computation patterns in a GMG algorithm includes stencils, point-wise accesses, restriction and interpolation of a grid. These computations can be optimized for performance on modern architectures using standard parallelization and locality enhancement techniques. Several past works have addressed the problem of automatic optimizations of computations in various scientific domains using a domain-specific language (DSL) approach. A DSL is a language with features to express domain-specific computations and compiler support to enable optimizations specific to these computations. Halide and PolyMage are two of the recent works in this direction, that aim to optimize image processing pipelines. Many computations like upsampling and downsampling an image are similar to interpolation and restriction in geometric multigrid methods. In this thesis, we demonstrate how high performance can be achieved on GMG algorithms written in the PolyMage domain-specific language with new optimizations we added to the compiler. We also discuss the implementation of non-trivial optimizations, on PolyMage compiler, necessary to achieve high parallel performance for multigrid methods on modern architectures. We realize these goals by: • introducing multigrid domain-specific constructs to minimize the verbosity of the algorithm specification; • storage remapping to reduce the memory footprint of the program and improve cache locality exploitation; • mitigating execution time spent in data handling operations like memory allocation and freeing, using a pool of memory, across multiple multigrid cycles; and • incorporating other well-known techniques to leverage performance, like exploiting multi-dimensional parallelism and minimizing the lifetime of storage buffers. We evaluate our optimizations on a modern multicore system using five different benchmarks varying in multigrid cycle structure, complexity and size, for two-and three-dimensional data grids. Experimental results show that our optimizations: • improve performance of existing PolyMage optimizer by 1.31x; • are better than straight-forward parallel and vector implementations by 3.2x; • are better than hand-optimized versions in conjunction with optimizations by Pluto, a state-of-the-art polyhedral source-to-source optimizer, by 1.23x; and • achieve up to 1.5$\times$ speedup over NAS MG benchmark from the NAS Parallel Benchmarks. (The speedup numbers are Geometric means over all benchmarks)
187

Falcon : A Graph Manipulation Language for Distributed Heterogeneous Systems

Cheramangalath, Unnikrishnan January 2017 (has links) (PDF)
Graphs model relationships across real-world entities in web graphs, social network graphs, and road network graphs. Graph algorithms analyze and transform a graph to discover graph properties or to apply a computation. For instance, a pagerank algorithm computes a rank for each page in a webgraph, and a community detection algorithm discovers likely communities in a social network, while a shortest path algorithm computes the quickest way to reach a place from another, in a road network. In Domains such as social information systems, the number of edges can be in billions or trillions. Such large graphs are processed on distributed computer systems or clusters. Graph algorithms can be executed on multi-core CPUs, GPUs with thousands of cores, multi-GPU devices, and CPU+GPU clusters, depending on the size of the graph object. While programming such algorithms on heterogeneous targets, a programmer is required to deal with parallelism and and also manage explicit data communication between distributed devices. This implies that a programmer is required to learn CUDA, OpenMP, MPI, etc., and also the details of the hardware architecture. Such codes are error prone and di cult to debug. A Domain Speci c Language (DSL) which hides all the hardware details and lets the programmer concentrate only the algorithmic logic will be very useful. With this as the research goal, Falcon, graph DSL and its compiler have been developed. Falcon programs are explicitly parallel and Falcon hides all the hardware details from the programmer. Large graphs that do not t into the memory of a single device are automatically partitioned by the Falcon compiler. Another feature of Falcon is that it supports mutation of graph objects and thus enables programming dynamic graph algorithms. The Falcon compiler converts a single DSL code to heterogeneous targets such as multi-core CPUs, GPUs, multi-GPU devices, and CPU+GPU clusters. Compiled codes of Falcon match or outperform state-of-the-art graph frameworks for di erent target platforms and benchmarks.
188

Réseaux de Petri temporels à inhibitions / permissions : application à la modélisation et vérification de systèmes de tâches temps réel / Forbid/Allow time Petri nets – Application to the modeling and checking of real time tasks systems

Peres, Florent 26 January 2010 (has links)
Les systèmes temps réel (STR) sont au coeur de machines souvent jugés critiques pour lasécurité : ils en contrôlent l’exécution afin que celles-ci se comportent de manière sûre dans le contexte d’un environnement dont l’évolution peut être imprévisible. Un STR n’a d’autre alternative que de s’adapter à son environnement : sa correction dépend des temps de réponses aux stimuli de ce dernier.Il est couramment admis que le formalisme des réseaux de Petri temporels (RdPT) est adapté àla description des STR. Cependant, la modélisation de systèmes simples, ne possédant que quelquestˆaches périodiques ordonnancées de façon basique se révèle être un exercice souvent complexe.En premier lieu, la modélisation efficace d’une gamme étendue de politiques d’ordonnancementsse heurte à l’incapacité des RdPT à imposer un ordre d’apparition à des évènements concurrentssurvenant au même instant. D’autre part, les STR ont une nette tendance à être constitués de caractéristiques récurrentes, autorisant une modélisation par composants. Or les RdPT ne sont guèreadaptés à une utilisation compositionnelle un tant soit peu générale. Afin de résoudre ces deuxproblèmes, nous proposons dans cette thèse Cifre – en partenariat entre Airbus et le Laas-Cnrs– d’étendre les RdPT à l’aide de deux nouvelles relations, les relations d’inhibition et de permission,permettant de spécifier de manière plus fine les contraintes de temps.Afin de cerner un périmètre clair d’adéquation de cette nouvelle extension à la modélisation dessystèmes temps réel, nous avons défini Pola, un langage spécifique poursuivant deux objectifs :déterminer un sous-ensemble des systèmes temps réel modélisables par les réseaux de Petri temporelsà inhibitions/permissions et fournir un langage simple à la communauté temps réel dont lavérification, idéalement automatique, est assurée par construction. Sa sémantique est donnée par traduction en réseaux de Petri temporels à inhibitions/permissions. L’explorateur d’espace d’états de laboite à outils Tina a été étendu afin de permettre la vérification des descriptions Pola / Real time systems (RTS) are at the core of safety critical devices : they control thedevices’ behavior in such a way that they remain safe with regard to an unpredictable environment. ARTS has no other choices than to adapt to its environment : its correctness depends upon its responsetime to the stimuli stemming from the environment.It is widely accepted that the Time Petri nets (TPN) formalism is adapted to the description ofRTS. However, the modeling of simple systems with only a few periodic tasks scheduled according toa basic policy remains a challenge in the worst case and can be very tedious in the most favorable one.First, we put forward some limitations of TPN regarding the modeling of a wide variety of schedulingpolicies, coming from the fact that this formalism is not always capable to impose a givenorder on events whenever they happen at the same time. Moreover, RTS are usually constituted of thesame recurring features, implying a compositional modeling, but TPN are not well adapted to sucha compositional use. To solve those problems we propose in this Cifre thesis – in partnership withAirbus and the Laas-Cnrs – to extend the formalism with two new dual relations, the forbid andallow relations so that time constraints can be finely tuned.Then, to assess this new extension for modeling of real time systems, we define Pola, a specificlanguage aimed at two goals : to determine a subset of RTS which can be modeled with forbid/allowtime Petri nets and to provide a simple language to the real time community which, ideally, can bechecked automatically. Its semantics is given by translation into forbid/allow Time Petri nets. Thestate space exploration tool of the Tina toolbox have been extended so that it can model check Poladescriptions.
189

Polymage : Automatic Optimization for Image Processing Pipelines

Mullapudi, Ravi Teja January 2015 (has links) (PDF)
Image processing pipelines are ubiquitous. Every image captured by a camera and every image uploaded on social networks like Google+or Facebook is processed by a pipeline. Applications in a wide range of domains like computational photography, computer vision and medical imaging use image processing pipelines. Many of these applications demand high-performance which requires effective utilization of modern architectures. Given the proliferation of camera enabled devices and social networks optimizing these emerging workloads has become important both at the data center and the embedded device scales. An image processing pipeline can be viewed as a graph of interconnected stages which process images successively. Each stage typically performs one of point-wise, stencil, sam-pling, reduction or data-dependent operations on image pixels. Individual stages in a pipeline typically exhibit abundant data parallelism that can be exploited with relative ease. However, the stages also require high memory bandwidth preventing effective uti-lization of parallelism available on modern architectures. The traditional options are using optimized libraries like OpenCV or to optimize manually. While using libraries precludes optimization across library routines, manual optimization accounting for both parallelism and locality is very tedious. Inthisthesis,wepresentthedesignandimplementationofPolyMage,adomain-specific language and compiler for image processing pipelines. The focus of the system is on au-tomatically generating high-performance implementations of image processing pipelines expressed in a high-level declarative language. We achieve such automation with: • tiling techniques to improve parallelism and locality by introducing redundant computation, v a model-driven fusion heuristic which enables a trade-off between locality and re-dundant computations, and anautotuner whichleveragesthefusionheuristictoexploreasmallsubsetofpipeline implementations and find the best performing one. Our optimization approach primarily relies on the transformation and code generation ca-pabilities of the polyhedral compiler framework. To the best of our knowledge, this is the first model-driven compiler for image processing pipelines that performs complex fusion, tiling, and storage optimization fully automatically. We evaluate our framework on a modern multicore system using a set of seven benchmarks which vary widely in structure and complexity. Experimental results show that the performance of pipeline implementations generated by our approach is: • up to 1.81× better than pipeline implementations manually tuned using Halide, a state-of-the-art language and compiler for image processing pipelines, • on average 5.39× better than pipeline implementations automatically tuned using Halide and OpenTuner, and • on average 3.3× better than naive pipeline implementations which only exploit par-allelism without optimizing for locality. We also demonstrate that the performance of PolyMage generated code is better or compa-rable to implementations using OpenCV, a state-of-the-art image processing and computer vision library.
190

Abordagem para criação de linguagens específicas de domínio para robótica móvel

Conrado, Daniel Bruno Fernandes 12 November 2012 (has links)
Made available in DSpace on 2016-06-02T19:06:01Z (GMT). No. of bitstreams: 1 4765.pdf: 5526051 bytes, checksum: eca7635e3ad1f0a28a9f3871c97aac57 (MD5) Previous issue date: 2012-11-12 / Universidade Federal de Sao Carlos / Autonomous mobile robots are machines capable of executing repetitive/dangerous tasks more efficiently. Most of them have an embedded software which is responsible for their execution. Over the last years, the complexity of these applications has continuously growing and they are presenting challenges that are uncommon to traditional information systems development. Therefore, any technique that can support their development is a great contribution. A technique that improves the productivity is to use domain-specific languages (DSLs). These are modeling and programming languages whose constructs are concepts and abstractions of a particular domain. It frees developers from worrying about generic programming concepts (classes, objects, attributes, etc.) and allows them to focus on the problem to be solved. As creating a DSL is not a trivial task and pointing the idiosyncrasies of mobile robots, this dissertation presents an approach for engineering DSLs to mobile robots. The aim is to make the activity of creating DSLs to this domain more systematic and controlled. In this approach, an application is taken as input and a series of domain statements is extracted from it. These statements are classified into categories and each one of them are analized in order to extract commonalities and variabilities, wich are transformed into components of a DSL. An important characteristic of the approach is that it asks for just one application to reach a first version of a running DSL. We suggest that the same DSL can be evolved just by applying the approach again using another application as input. So new components could be created and the existing ones could be modified. We also present a generic language model providing a foundation architecture that allows one to easily create new DSLs by extending it. Two proofs of concept are presented in order to exemplify the application of our approach. / Robôs móveis autônomos são máquinas com potencial para realizar atividades repetitivas ou de alta periculosidade com mais eficácia. Muitos possuem um software embarcado responsável pelo seu funcionamento. Nos últimos anos, a complexidade dessas aplicações robóticas embarcadas tem crescido continuamente e apresentam desafios que são incomuns ao desenvolvimento dos tradicionais sistemas de informação. Portanto, toda técnica que dê suporte a esse tipo de desenvolvimento pode contribuir significativamente. Uma técnica que permite o aumento de produtividade é a utilização de linguagens específicas de domínio (DSLs). Essas são linguagens de modelagem e programação cujas construções são conceitos e abstrações de um domínio de aplicação em particular. Isso desobriga o desenvolvedor de se preocupar com conceitos genéricos de programação (classes, objetos, atributos, etc.) para focar-se no problema a ser resolvido. Como o desenvolvimento de uma DSL não é uma tarefa trivial e tendo em vista as idiossincrasias dos robôs móveis autônomos, esta dissertação apresenta uma abordagem para construção de DSLs para robôs móveis. O objetivo é deixar mais sistemática e controlada a criação de DSLs para esse domínio. Nessa abordagem, uma aplicação é tomada como entrada e dela extraem-se declarações a respeito do domínio. Essas declarações são categorizadas e, para cada categoria, são levantadas partes comuns e variáveis. Então, essas partes são transformadas em componentes de uma DSL. Uma característica importante da abordagem apresentada é que uma versão inicial da DSL pode ser alcançada tendo apenas uma aplicação como base. Sugere-se que essa mesma DSL possa evoluir pela reaplicação da abordagem tendo uma nova aplicação como entrada. Dessa forma, novos componentes podem ser criados e os existentes, modificados. Também é apresentado um modelo genérico de linguagem que fornece uma arquitetura básica, permitindo que novas DSLs sejam facilmente construídas pela extensão da mesma. Duas provas de conceito são apresentadas com a intenção de exemplificar a aplicação da abordagem.

Page generated in 0.0484 seconds