The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

L. Ya. Vulakh - One of the best experts on this subject based on the ideXlab platform.

  • THE MARKOV SPECTRA FOR COCOMPACT FUCHSIAN GROUPS
    International Journal of Number Theory, 2009
    Co-Authors: L. Ya. Vulakh
    Abstract:

    Applying the Klein model D2 of the hyperbolic plane and identifying the geodesics in D2 with their poles in the projective plane, the author has developed a method for finding the Discrete Part of the Markov spectrum for Fuchsian groups. It is applicable mostly to non-cocompact groups. In the present paper, this method is extended to cocompact Fuchsian groups. For a group with signature (0;2,2,2,3), the complete description of the Discrete Part of the Markov spectrum is obtained. The result obtained leads to the complete description of the Markov and Lagrange spectra for the imaginary quadratic field with discriminant -20.

  • DIOPHANTINE APPROXIMATION IN $\mathbf{Q}(\sqrt{-5})$ AND $\mathbf{Q}(\sqrt{-6})$
    International Journal of Number Theory, 2006
    Co-Authors: L. Ya. Vulakh
    Abstract:

    The complete description of the Discrete Part of the Lagrange and Markov spectra of the imaginary quadratic fields with discriminants -20 and -24 are given. Farey polygons associated with the extended Bianchi groups Bd, d = 5, 6, are used to reduce the problem of finding the Discrete Part of the Markov spectrum for the group Bd to the corresponding problem for one of its maximal Fuchsian subgroup. Hermitian points in the Markov spectrum of Bd are introduced for any d. Let H3 be the upper half-space model of the three-dimensional hyperbolic space. If ν is a hermitian point in the spectrum, then there is a set of extremal geodesics in H3 with diameter 1/ν, which depends on one continuous parameter. This phenomenon does not take place in the hyperbolic plane.

Mohsen Soltanifar - One of the best experts on this subject based on the ideXlab platform.

Hans Holm - One of the best experts on this subject based on the ideXlab platform.

  • Information structures for design of feedback resource distribution control systems for Discrete Part manufacture
    International Journal of Computer Integrated Manufacturing, 2006
    Co-Authors: Hans Holm
    Abstract:

    Increased pressure for efficiency improvement on Discrete Part manufacture justifies investment in design and implementation of control systems for distribution of resources in a manufacturing plant. Design of such systems is, however, to day based on intuition. In the paper a systematic method for design of such control systems is described. The paper presents the generic structure of such control systems including definition of input, state and output vectors. Definition of the set of events, which cause choice of input and corresponding transition from one state into another one, is presented. Additionally the paper presents a method for identification and representation of the degrees of freedom, which are available for the choice of system input in reaction to valid classes of appearing production events. The paper finally presents the structure of the state space of the control system and the principle according to which it is expanded and searched for optimal control input.

  • Hybrid state plant model constraints for design of control systems for Discrete Part manufacture resource distribution
    Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301), 2002
    Co-Authors: Hans Holm
    Abstract:

    Material- and product transformations of Discrete Part manufacture are performed through sequences of continuous processes. The sequences of the transformations are in most humanly operated manufacture today determined Partly by conscious planning Partly by non conscious planning. Basis of the planning is deterministic transformation durations. This paper establishes a rational system framework upon which rational methods for design of systems for the control of distribution of resources for Discrete Parts manufacture can be developed.

Wim Dewulf - One of the best experts on this subject based on the ideXlab platform.

  • Environmental Impact Modeling of Discrete Part Manufacturing Processes
    Leveraging Technology for a Sustainable World, 2012
    Co-Authors: Karel Kellens, Renaldi, Wim Dewulf, Joost R. Duflou
    Abstract:

    Environmental analyses of standalone unit manufacturing processes as well as full process chains indicate improvement potential at machine tool architecture, process control as well as production planning level leading to lower environmental footprints of Discrete Part manufacturing processes. This paper presents a framework, illustrated by a case-study for laser cutting, to establish parametric environmental process models, for example to be used in simulation tools. Furthermore, the framework supports the development of generic LCI-datasets based on comparing and aggregating environmental analyses of a range of similar machine tools (several suppliers and machine tool capacities).

  • Unit process impact assessment for Discrete Part manufacturing: A state of the art
    CIRP Journal of Manufacturing Science and Technology, 2011
    Co-Authors: Joost Duflou, Karel Kellens, Wim Dewulf
    Abstract:

    Abstract Manufacturing processes, as used for Discrete Part manufacturing, are responsible for a substantial Part of the environmental impact of products, but are still poorly documented in terms of their environmental footprint. The lack of thorough analysis of manufacturing processes has as consequence that optimization opportunities are often not recognized and that improved machine tool design in terms of ecological footprint has only been targeted for a few common processes. To address these shortcomings, a worldwide consortium of universities and research institutes launched the CO 2 PE! – Initiative (Cooperative Effort on Process Emissions in Manufacturing) [1] . This paper starts with an overview of the current shortcomings in terms of the coverage of production steps during LCA studies with existing tools. Further on, the CO 2 PE! – methodology used to analyze manufacturing unit processes is summarized and some initial case studies conducted at the K.U. Leuven, which allowed to identify significant improvement potential, are presented.

  • Improvement Potential for Energy Consumption in Discrete Part Production Machines
    Advances in Life Cycle Engineering for Sustainable Manufacturing Businesses, 1
    Co-Authors: Tom Devoldere, Wim Dewulf, Wim Deprez, Barbara Willems, Joost Duflou
    Abstract:

    Industrial production inevitably results in an environmental impact. Energy consumption is responsible for a substantial Part of this impact. Currently, machine designers spend little attention to minimising the energy consumption, since their primary focus is on the well-functioning of the machine.

Mohammed A. Saifi - One of the best experts on this subject based on the ideXlab platform.

  • A Decision Support System for Flexibility Enabled Discrete Part Manufacturing System
    Global Journal of Flexible Systems Management, 2011
    Co-Authors: Mohammed Ali, Mohammed A. Saifi
    Abstract:

    This paper discusses how simulation can be used as decision support system. Simulation technique is used to evaluate the performance of flexibility enabled manufacturing system. This manufacturing system produces Discrete Part at regular interval. The ultimate goal of this paper is to find out the way to reduce work-in-process inventory, maintain high production rate and also to find out time taken to produce a product. We expect that reducing inventory will lead to shorter make-span time, which will ultimately improve production rate. This work is also concerned with identifying bottleneck resources and eliminating bottleneck by applying routing flexibility in the system. Routing flexibility helps in redistribution of load and ultimately leading to the improvement in the performance of the system.