9,645 research outputs found
Knowledge Reuse for Customization: Metamodels in an Open Design Community for 3d Printing
Theories of knowledge reuse posit two distinct processes: reuse for
replication and reuse for innovation. We identify another distinct process,
reuse for customization. Reuse for customization is a process in which
designers manipulate the parameters of metamodels to produce models that
fulfill their personal needs. We test hypotheses about reuse for customization
in Thingiverse, a community of designers that shares files for
three-dimensional printing. 3D metamodels are reused more often than the 3D
models they generate. The reuse of metamodels is amplified when the metamodels
are created by designers with greater community experience. Metamodels make the
community's design knowledge available for reuse for customization-or further
extension of the metamodels, a kind of reuse for innovation
Sensitivity Analysis of Simulation Models
This contribution presents an overview of sensitivity analysis of simulation models, including the estimation of gradients. It covers classic designs and their corresponding (meta)models; namely, resolution-III designs including fractional-factorial two-level designs for first-order polynomial metamodels, resolution-IV and resolution-V designs for metamodels augmented with two-factor interactions, and designs for second-degree polynomial metamodels including central composite designs. It also reviews factor screening for simulation models with very many factors, focusing on the so-called "sequential bifurcation" method. Furthermore, it reviews Kriging metamodels and their designs. It mentions that sensitivity analysis may also aim at the optimization of the simulated system, allowing multiple random simulation outputs.simulation;sensitivity analysis;gradients;screening;Kriging;optimization;Response SurfaceMethodology;Taguchi
A Practical Example for Model-Driven Web Requirements
The number of approaches for Web environments has grown very fast
in the last years: HDM, OOHDM, and WSDM were among the first, and now a
large number can be found in the literature. With the definition of MDA (Model-
Driven Architecture) and the acceptance of MDE (Model-Driven Engineering)
techniques in this environment, some groups are working in the use of metamodels
and transformations to make their approaches more powerful. UWE (UMLBased
Web Engineering) or OOWS (Object-Oriented Web Solutions) are only
some examples. However, there are few real experiences with Web Engineering in
the enterprise environment, and very few real applications of metamodels and
MDE techniques. In this chapter the practical experience of a Web Engineering
approach, NDT, in a big project developed in Andalusia is presented. Besides, it
shows the usability of metamodels in real environments
Evaluation of Kermeta for Solving Graph-based Problems
Kermeta is a meta-language for specifying the structure and behavior of graphs of interconnected objects called models. In this paper,\ud
we show that Kermeta is relatively suitable for solving three graph-based\ud
problems. First, Kermeta allows the specification of generic model\ud
transformations such as refactorings that we apply to different metamodels\ud
including Ecore, Java, and Uml. Second, we demonstrate the extensibility\ud
of Kermeta to the formal language Alloy using an inter-language model\ud
transformation. Kermeta uses Alloy to generate recommendations for\ud
completing partially specified models. Third, we show that the Kermeta\ud
compiler achieves better execution time and memory performance compared\ud
to similar graph-based approaches using a common case study. The\ud
three solutions proposed for those graph-based problems and their\ud
evaluation with Kermeta according to the criteria of genericity,\ud
extensibility, and performance are the main contribution of the paper.\ud
Another contribution is the comparison of these solutions with those\ud
proposed by other graph-based tools
Generic Model Refactorings
Many modeling languages share some common concepts and principles. For example, Java, MOF, and UML share some aspects of the concepts\ud
of classes, methods, attributes, and inheritance. However, model\ud
transformations such as refactorings specified for a given language\ud
cannot be readily reused for another language because their related\ud
metamodels may be structurally different. Our aim is to enable a\ud
flexible reuse of model transformations across various metamodels.\ud
Thus, in this paper, we present an approach allowing the specification\ud
of generic model transformations, in particular refactorings, so\ud
that they can be applied to different metamodels. Our approach relies\ud
on two mechanisms: (1) an adaptation based mainly on the weaving\ud
of aspects; (2) the notion of model typing, an extension of object\ud
typing in the model-oriented context. We validated our approach by\ud
performing some experiments that consisted of specifying three well\ud
known refactorings (Encapsulate Field, Move Method, and Pull Up Method)\ud
and applying each of them onto three different metamodels (Java,\ud
MOF, and UML)
Sensitivity analysis of expensive black-box systems using metamodeling
Simulations are becoming ever more common as a tool for designing complex
products. Sensitivity analysis techniques can be applied to these simulations
to gain insight, or to reduce the complexity of the problem at hand. However,
these simulators are often expensive to evaluate and sensitivity analysis
typically requires a large amount of evaluations. Metamodeling has been
successfully applied in the past to reduce the amount of required evaluations
for design tasks such as optimization and design space exploration. In this
paper, we propose a novel sensitivity analysis algorithm for variance and
derivative based indices using sequential sampling and metamodeling. Several
stopping criteria are proposed and investigated to keep the total number of
evaluations minimal. The results show that both variance and derivative based
techniques can be accurately computed with a minimal amount of evaluations
using fast metamodels and FLOLA-Voronoi or density sequential sampling
algorithms.Comment: proceedings of winter simulation conference 201
A methodological proposal and tool support for the HL7 standards compliance in the development of health information systems
Health information systems are increasingly complex, and their development is presented as a challenge for software development companies offering quality, maintainable and interoperable products. HL7 (Health level 7) International, an international non-profit organization, defines and maintains standards related to health information systems. However, the modelling languages proposed by HL7 are far removed from standard languages and widely known by software engineers. In these lines, NDT is a software development methodology that has a support tool called NDT-Suite and is based, on the one hand, on the paradigm of model-driven engineering and, on the other hand, in UML that is a widely recognized standard language. This paper proposes an extension of the NDT methodology called MoDHE (Model Driven Health Engineering) to offer software engineers a methodology capable of modelling health information systems conforming to HL7 using UML domain models
Towards a pivotal-based approach for business process alignment.
This article focuses on business process engineering, especially on alignment between business analysis and implementation. Through a business process management approach, different transformations interfere with process models in order to make them executable. To keep the consistency of process model from business model to IT model, we propose a pivotal metamodel-centric methodology. It aims at keeping or giving all requisite structural and semantic data needed to perform such transformations without loss of information. Through this we can ensure the alignment between business and IT. This article describes the concept of pivotal metamodel and proposes a methodology using such an approach. In addition, we present an example and the resulting benefits
Towards maintainer script modernization in FOSS distributions
Free and Open Source Software (FOSS) distributions are complex software
systems, made of thousands packages that evolve rapidly, independently, and
without centralized coordination. During packages upgrades, corner case
failures can be encountered and are hard to deal with, especially when they are
due to misbehaving maintainer scripts: executable code snippets used to
finalize package configuration. In this paper we report a software
modernization experience, the process of representing existing legacy systems
in terms of models, applied to FOSS distributions. We present a process to
define meta-models that enable dealing with upgrade failures and help rolling
back from them, taking into account maintainer scripts. The process has been
applied to widely used FOSS distributions and we report about such experiences
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