6,410 research outputs found
Two Decades of Maude
This paper is a tribute to José Meseguer, from the rest of us in the Maude team, reviewing the past, the present, and the future of the language and system with which we have been working for around two decades under his leadership. After reviewing the origins and the language's main features, we present the latest additions to the language and some features currently under development. This paper is not an introduction to Maude, and some familiarity with it and with rewriting logic are indeed assumed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
The Hopfield model and its role in the development of synthetic biology
Neural network models make extensive use of
concepts coming from physics and engineering. How do scientists
justify the use of these concepts in the representation of
biological systems? How is evidence for or against the use of
these concepts produced in the application and manipulation
of the models? It will be shown in this article that neural
network models are evaluated differently depending on the
scientific context and its modeling practice. In the case of
the Hopfield model, the different modeling practices related to
theoretical physics and neurobiology played a central role for
how the model was received and used in the different scientific
communities. In theoretical physics, where the Hopfield model
has its roots, mathematical modeling is much more common and
established than in neurobiology which is strongly experiment
driven. These differences in modeling practice contributed to
the development of the new field of synthetic biology which
introduced a third type of model which combines mathematical
modeling and experimenting on biological systems and by doing
so mediates between the different modeling practices
Intelligent Computing for the Management of Changes in Industrial Engineering Modeling Processes
Advancements in engineering modeling have changed the work of engineers during the last two decades. Sophisticated descriptions store information about shape oriented engineering objects and their relationships. Boundary representations of form features constitute shape models. Rules and checks have replaced simple data form of shape model entity attributes. This change of modeling facilitates a next step towards application of computer intelligence at engineering object related decisions. The authors propose a method of intelligent attribute definition for integrated decision assistance environments of modelling systems. This method provides quick and comprehensive assessment of situations for decisions on modification of modeled objects in very complex information environments. The paper starts with an outline of the approach to intelligent decision assistance by the authors. Next, an Internet portal communicated scenario of the proposed modeling is discussed. Following this, multilevel solution for modeling, adding characteristics for engineering objects, and definitions and communications are detailed as essential methods in the proposed modeling. Finally, behaviors for essential classes of modeled objects and an example for the definition of situations and behaviors represent implementation issues
Design of testbed and emulation tools
The research summarized was concerned with the design of testbed and emulation tools suitable to assist in projecting, with reasonable accuracy, the expected performance of highly concurrent computing systems on large, complete applications. Such testbed and emulation tools are intended for the eventual use of those exploring new concurrent system architectures and organizations, either as users or as designers of such systems. While a range of alternatives was considered, a software based set of hierarchical tools was chosen to provide maximum flexibility, to ease in moving to new computers as technology improves and to take advantage of the inherent reliability and availability of commercially available computing systems
Intelligent systems in manufacturing: current developments and future prospects
Global competition and rapidly changing customer requirements are demanding increasing changes in manufacturing environments. Enterprises are required to constantly redesign their products and continuously reconfigure their manufacturing systems. Traditional approaches to manufacturing systems do not fully satisfy this new situation. Many authors have proposed that artificial intelligence will bring the flexibility and efficiency needed by manufacturing systems. This paper is a review of artificial intelligence techniques used in manufacturing systems. The paper first defines the components of a simplified intelligent manufacturing systems (IMS), the different Artificial Intelligence (AI) techniques to be considered and then shows how these AI techniques are used for the components of IMS
An Object-Oriented Model for Extensible Concurrent Systems: the Composition-Filters Approach
Applying the object-oriented paradigm for the development of large and complex software systems offers several advantages, of which increased extensibility and reusability are the most prominent ones. The object-oriented model is also quite suitable for modeling concurrent systems. However, it appears that extensibility and reusability of concurrent applications is far from trivial. The problems that arise, the so-called inheritance anomalies are analyzed and presented in this paper. A set of requirements for extensible concurrent languages is formulated. As a solution to the identified problems, an extension to the object-oriented model is presented; composition filters. Composition filters capture messages and can express certain constraints and operations on these messages, for example buffering. In this paper we explain the composition filters approach, demonstrate its expressive power through a number of examples and show that composition filters do not suffer from the inheritance anomalies and fulfill the requirements that were established
Parametric CAD modeling: An analysis of strategies for design reusability
CAD model quality in parametric design scenarios largely determines the level of flexibility and adaptability of a 3D model (how easy it is to alter the geometry) as well as its reusability (the ability to use existing geometry in other contexts and applications). In the context of mechanical CAD systems, the nature of the feature-based parametric modeling paradigm, which is based on parent-child interdependencies between features, allows a wide selection of approaches for creating a specific model. Despite the virtually unlimited range of possible strategies for modeling a part, only a small number of them can guarantee an appropriate internal structure which results in a truly reusable CAD model. In this paper, we present an analysis of formal CAD modeling strategies and best practices for history-based parametric design: Delphi's horizontal modeling, explicit reference modeling, and resilient modeling. Aspects considered in our study include the rationale to avoid the creation of unnecessary feature interdependencies, the sequence and selection criteria for those features, and the effects of parent/child relations on model alteration. We provide a comparative evaluation of these strategies in the form of a series of experiments using three industrial CAD models with different levels of complexity. We analyze the internal structure of the models and compare their robustness and flexibility when the geometry is modified. The results reveal significant advantages of formal modeling methodologies, particularly resilient techniques, over non-structured approaches as well as the unexpected problems of the horizontal strategy in numerous modeling situations. (C)2016 Elsevier Ltd. All rights reserved.Camba, JD.; Contero, M.; Company, P. (2016). Parametric CAD modeling: An analysis of strategies for design reusability. Computer-Aided Design. 74:18-31. doi:10.1016/j.cad.2016.01.003S18317
Uključivanje 3D modeliranja tijela u kolegij inženjerske grafike
The increasing use of solid modelling has had considerable impact on
changes in the design process, which has resulted in a stronger relation
between design and engineering graphics. These attempts can be followed
shifting from modest changes, by inserting 2D and 3D CAD models into
introductory engineering graphics course to the approach of implementing
parametric, feature-based and constraint-based modelling, which have led
towards the development of 3D model centred engineering curriculum.
This paper presents some characteristic approaches chosen from numerous
contributions dealing with the introduction of new topics and technology
in engineering graphics education, as well as the example of 3D model-
centred engineering curriculum. A review of topics that are the most
common proposal for an introductory engineering graphics course are
extracted, regardless of different approaches that should accomplish the
link between 3D modelling, engineering design and applications.
A short description of engineering graphics courses and the topics covered
at the University of Rijeka, Faculty of Engineering, as a result of revision
that has emphasized 3D modelling and its role in the concurrent engineering
design process is also presented.Na promjene u procesu konstruiranja znatno je utjecala povećana upo-
raba modeliranja tijela, što je rezultiralo snažnijim odnosom između kon-
struiranja i inženjerske grafike. Mogu se pratiti nastojanja, od stidljivih
promjena uključivanjem 2D i 3D modela u uvodni kolegij inženjerske
grafike, do pristupa upotpunjavanja parametarskim modeliranjem na os-
novi značajke i ograničenja, što dovodi do razvitka inženjerskog nastavnog
programa s 3D modelom u središtu.
Ovaj rad predstavlja neke karakteristične pristupe izabrane iz brojnih
doprinosa koji obrađuju uvođenje novih tema i tehnologija u obrazovanje
inženjerske grafike, kao i primjer inženjerskog nastavnog programa s 3D
modelom u središtu. Izdvojen je pregled tema koje su najčešći prijedlog
za uvodni kolegij inženjerske grafike, bez obzira na različite pristupe koji
trebaju ostvariti vezu između 3D modeliranja, inženjerskog konstruiranja
i aplikacija.
Također je predstavljen kratki opis kolegija inženjerske grafike i
obuhvaćenih tema na Tehničkom fakultetu u Rijeci, kao rezultat dorada
koje daju naglasak na 3D modeliranje i njegovu ulogu u procesu istodobnog
inženjerskog konstruiranja
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