Mounib Mekhilef

Optimization of a NURBS representation

Abstract One of the main problems in modelling curves and surfaces with nonuniform rational B-splines is the choice of the knots and weights. The paper describes a global numerical method for the optimization of these parameters. The Polak-Ribiere technique, with some improvements, is used to minimize a cost function. Different cases of curves have been studied with various conditions of geometric continuity. Some interpretations of the weights and positions of the vertices are given. The paper concludes with some rules for the choice of knot configuration.

A pragmatic methodology to capture and analyse decision dysfunctions in development projects

The aim of this article is to present the results of our recent work in the field of development projects management. The issue that we have raised is to determine the dysfunction profile of a company. From an approach developed in maintenance, we propound on one hand a generic plan of the decision-making process, and on the other, we recapitulate work connected with competence management, to offer a representation frame of dysfunction sources. This double entry has the advantage of supplying views that take into account the human being, and thus, which are more realistic. Then, on an operational level, we set out an information index card summing up the two previous plans that helps the documentation of decision processes. We apply the associated methodology called SACADO to the case of a company, and finally, we report and examine the results

Development of Knowledge Based System to Facilitate Design of On-Board Car Safety Systems

The development of on-board car safety systems requires an accidentology knowledge base for the development of new functionalities as well as their improvement and evaluation. The Knowledge Discovery in accident Database (KDD) is one of the approaches allowing the construction of this knowledge base. However, considering the complexity of the accident data and the variety of their sources (biomechanics, psychology, mechanics, ergonomics, etc.), the analytical methods of the KDD (clustering, classification, association rules etc.) should be combined with expert approaches. Indeed, there is background knowledge in accidentology which exists in the minds of accidentologist experts and which is not formalized in the accident database. The aim of this paper is to develop a Knowledge Representation Model (KRM) intended to incorporate this knowledge in the KDD process. The KRM is implemented in a knowledge-based system, which provides an expert classification of the attributes characterizing an accident. This expert classification provides an efficient tool for data preparation in a KDD process. Our method consists of combining the modeling systemic approach of complex systems and the modeling cognitive approach KOD (Knowledge Oriented Design) in knowledge engineering.© 2003 ASME

Proposal of a Functional Model of Logistics for Spare Parts Preservation

This paper deals with the determination of the optimal logistic chain for the spare parts preservation for the nuclear civil plants. Since a nuclear power plant is designed for a use during at least 30 years, the question relative to the availability of the parts, to be used a long time after the plant design, is crucial and strategic. In other words the question is: “how to preserve the spare parts and where?”

Twinkling a Random Search Algorithm for Design Optimization

In this paper we are going to show that applying the twinkling technique on a naive random search algorithm is frequently more powerful than any algorithm using specific research techniques unless they use information provided by the gradient or the Hessian. In order to illustrate this result we have made the choice of the study of a mechanical system characterized by the non-linear nature of the optimization space. This system is basically an open kinematics chain that represents a robot which has to go through various different trajectories defined by a set of temporally equidistant points. In fact, we are going to show that the genetic algorithm, the simulated annealing algorithm, the particle swarm algorithm, the random search algorithm, need to use comparatively, a huge number of function evaluations in order to perform the same result quality.Copyright

A Knowledge-Based System for Change Impact Analysis

Due to the increasing complexity of the modern industrial context in an evolutionary environment, several changes (e.g. new technology, new system, human errors, etc.) may affect road safety. Analyzing the change impact on design requirements is a complex task especially when it deals with complex systems such as Vehicle Safety Systems (VSS). To handle a change impact analysis in road safety field, VSS designers require a specific knowledge stemmed from accidentology. In this paper, we develop a multi-view model of the road accident, which is crucial to extract the required knowledge. Indeed, this multi-view model allows the analysis of the impact of a given change on the Driver-Vehicle-Environment system from different viewpoints and on different grain of size. This allows an efficient approach to detect exhaustively the perturbations due to the change and thereby to anticipate and handle their effects. We use a Knowledge Engineering approach to implement the multi-view model in a Knowledge-Based System providing accidentologists and VSS designers with an efficient tool to carry out an analysis of change impact on analysis design requirements.Copyright

Knowledge Management: A Concept Review

The reality of the Knowledge Management (KM) joins in a multiplicity of ends and situations. In the scientific literature, KM seems to appear as a sort of more or less unified and more or less generative “field of research” of specialists’ community. Nevertheless, a detailed analysis of the scientific production relative to the Knowledge Management shows essentially that the management of knowledge and competence became a preoccupation in a big part of sciences and techniques. This is translated by a big number of actors (university, consultant, industrial, etc.) constituting a community of preoccupations. It deals also with a profusion of publications, various networks and a rising offer of specialized trainings. However, the big variety of points of view and interpretations which join to the knowledge and competence management calls up to a lot of caution as for any other scientific discipline, and invites to understand the senses which are given to them. Indeed, no fundamental scientific result appeared really: literature supplies only approaches which hold more feeling than it is important, or very pragmatic applications, sending back mostly to particular cases of companies.Copyright

Knowledge Management in Design: A Perspective?

In recent years Knowledge Management (KM) is becoming a necessity for many companies interested in meeting the challenges of ongoing organizational changes and growing global competitiveness. In scientific literature KM appears more or less a unified but somewhat generative ‘field of research’. A detailed analysis of the scientific works in KM, however, reveals that the management of knowledge and competence has become a preoccupation in its own right. A number of actors (university, consultant, industrial, etc.) now constitute a large community of KM experts with a profusion of publications, various network groups, and specialized training offers. Currently, there exist several points of view and interpretations to the notion of knowledge and competence management. From the research perspective, the developments in KM are spreading in many fields, including: Decision Science, Social Sciences, Engineering, Computer Science, Medicine, Business, and Economy. The processes related to the knowledge life cycle are currently being evaluated from several angles including well established pragmatic point of views. There are actually strong relations between the pragmatic points of view and the arguments of more ontological nature. Papers addressing both these points of view are covered in the current issue. For example, when knowledge is envisaged as ‘information organized for the resolution of problems’ the idea of knowledge therein implicitly represents entities that are already formalized. This is quite different compared to a resolution process (such as statements susceptible to formal treatments) or, a minima, in organized categories without having formal processes or a priori treatment. If an author deals with KM from a specific field or discipline (say information sciences, or engineering), the true meaning and the practical echo of the underlying concepts will not be of the same nature. In other words, the notion of knowledge must be considered both from a pragmatic point of view (what it conveys in a certain context or action) and in reference to an ontological context (such as a universe). Consequently, the epistemological level would be an important consideration. In addition, two other contextualization of the pragmatic approach should also be considered in dealing with KM:

Knowledge Sharing Between Designers and Accidentologists for the Development of Road Safety Systems

Road Safety System development is complex task, which requires the collaboration between designers and accidentologists. However, designers and accidentologists do not share the same viewpoints, neither the same models to analyze an accident, nor the same technical language. This makes their communication a complex task in a design process. Accident Scenario is recognized as a powerful communication tool between designers and accidentologists. Nevertheless, an accident scenario has to be presented in a way that both designers and accidentologists can understand and use. To address this issue, we use the systemic approach (a complex system modeling approach) to develop a new methodology allowing constructing multi-view accident scenarios.Copyright

A Quantitative Analysis of the Evolution of Design Automation Conference Fields

A quick look to the literature related to “Design” points out the fact that traditional fields are covered by a huge quantity of concepts and sub-topics dealing with various research fields. Some of these fields and related concepts are emerging and others are disappearing. The last two decades provided a large variations in the covered fields—probably because of the computers capacity and the knowledge sharing using the internet- We are convinced that is time now for a global understanding of the evolution of the related preoccupations in order to start a new phase that deals with the next guidelines issues in design. Many researchers and gurus have proposed evolution schemes from an epistemological point of view. However, we believe that we still need a pragmatic analysis of what have been done and what is going on now in the various publications that deals with design, conferences and journals. To do so, we present in this paper an approach that lies on the systematic analysis of the International Design Engineering Technical Conference (IDETC-ASME), the Design Conference, the Integrated Design and Manufacturing in Mechanical Engineering (IDMME) and the International Conference in Engineering Design (ICED). We also consider the major reviews and journals related to design such as Computer-Aided Design, Journal of mechanical design and many others. Our proposition, presents a global overview that shows the time-evolution of the topics, the density production, the emerging areas and concepts. We show then that some topics remain with a great interest and other are in a decreasing period. A specific study of what is going on within the Design Automation Conference is provided and an open discussion is started.Copyright