1,332 research outputs found

    The application of multi-objective robust design methods in ship design

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    When designing large complex vessels, the evaluation of a particular design can be both complicated and time consuming. Designers often resort to the use of concept design models enabling both a reduction in complexity and time for evaluation. Various optimisation methods are then typically used to explore the design space facilitating the selection of optimum or near optimum designs. It is now possible to incorporate considerations of seakeeping, stability and costs at the earliest stage in the ship design process. However, to ensure that reliable results are obtained, the models used are generally complex and computationally expensive. Methods have been developed which avoid the necessity to carry out an exhaustive search of the complete design space. One such method is described which is concerned with the application of the theory of Design Of Experiments (DOE) enabling the design space to be efficiently explored. The objective of the DOE stage is to produce response surfaces which can then be used by an optimisation module to search the design space. It is assumed that the concept exploration tool whilst being a simplification of the design problem, is still sufficiently complicated to enable reliable evaluations of a particular design concept. The response surface is used as a representation of the concept exploration tool, and by it's nature can be used to rapidly evaluate a design concept hence reducing concept exploration time. While the methodology has a wide applicability in ship design and production, it is illustrated by its application to the design of a catamaran with respect to seakeeping. The paper presents results exploring the design space for the catamaran. A concept is selected which is robust with respect to the Relative Bow Motion (RBM), the heave, pitch and roll at any particular waveheading. The design space is defined by six controllable design parameters; hull length, breadth to draught ratio, distance between demihull centres, coefficient of waterplane, longitudinal centre of floatation, longitudinal centre of buoyancy, and by one noise parameter, the waveheading. A Pareto-optimal set of solutions is obtained using RBM, heave, pitch and roll as criteria. The designer can then select from this set the design which most closely satisfies their requirements. Typical solutions are shown to yield average reductions of over 25% in the objective functions when compared to earlier results obtained using conventional optimisation methods

    Multi-objective robust concept exploration within the made-to-order sector

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    Concept exploration is an activity of fundamental importance when designing large, complex made-to-order engineering products. At the concept design stage of the design process, it is essential that many design alternatives are evaluated. In the case of large made-to-order products, the evaluation of a particular design can be both complicated and time consuming. Under these circumstances, designers often resort to the use of concept design models enabling both a reduction in complexity and time for evaluation. Stochastic optimisation methods are then typically used to explore the design space facilitating the selection of optimum or near optimum designs. These optimisation methods can however increase the concept exploration time considerably due to their often random search manner. The objective of this work is therefore to produce a generic framework that would enable a designer to efficiently explore the design space within the MTO domain facilitating the selection of robust designs

    A multi-agent based system to enable strategic and operational design coordination

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    This paper presents two systems which individually focus on different aspects of design coordination, namely strategic and operational. The systems were developed in parallel and individually contain related models that represent specific frames from a Design Coordination Framework developed by Andreasen et al. [1]. The focus of the strategic design management system is the management of design tasks, decisions, information, goals and rationale within the design process, whereas the focus of the operational design coordination system is the coordination of tasks and activities with respect to the near-optimal utilisation of available resources. A common interface exists which enables the two systems to be integrated and used as a single system with the aim of managing both strategicand operational design coordination. Hence, the objective of this work is to enable the design process to be conducted in a timely and appropriate manner

    Coordination approaches and systems - part II : an operational perspective

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    This is the second of two papers surveying research in coordination approaches and systems. This paper is concerned with operational coordination, which is aimed at coordinating activities such that the design process can be performed in a near optimal manner with respect to time, and the allocation and utilisation of resources. Aspects of coordination categorised as operational include resource management, scheduling and planning. The first of these two papers presents a review of coordination from a strategic perspective, which is concerned with the decision management aspects of coordination. Greater emphasis is now being placed on the significance of organising the design process as this affects time to market, product quality, cost, and consequently product success. The aim of this paper is to present a fundamental review of operational coordination approaches and systems. The 1990s has seen much progress being made towards a greater understanding and appreciation of coordination in various disciplines through the development of a wide range of approaches and systems. However, there remains a requirement to formally identify the key issues involved in coordination such that a widely accepted representation can be agreed upon. Consequently, research should continue to be supported in the exploration for a unified approach to coordination which will permit a broader and greater understanding of those aspects involved

    A system for co-ordinating concurrent engineering

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    Design of large made-to-order products invariably involves design activities which are increasingly being distributed globally in order to reduce costs, gain competitive advantage and utilise external expertise and resources. Designers specialise within their domain producing solutions to design problems using the tools and techniques with which they are familiar. They possess a relatively local perception of where their expertise and actions are consumed within the design process. This is further compounded when design activities are geographically distributed, resulting with the increased disassociation between an individual designer's activities and the overall design process. The tools and techniques used by designers rarely facilitate concurrency, producing solutions within a particular discipline without using or sharing information from other disciplines, and seldom considering stages within the product's life-cycle other than conceptual, embodiment or detail [1, 2]. Conventional management and maintenance of consistency throughout the product model can subsequently become difficult to achieve since there are many factors that need to be simultaneously considered whilst making achange to the product model

    Coordination approaches and systems - part I : a strategic perspective

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    This is the first part of a two-part paper presenting a fundamental review and summary of research of design coordination and cooperation technologies. The theme of this review is aimed at the research conducted within the decision management aspect of design coordination. The focus is therefore on the strategies involved in making decisions and how these strategies are used to satisfy design requirements. The paper reviews research within collaborative and coordinated design, project and workflow management, and, task and organization models. The research reviewed has attempted to identify fundamental coordination mechanisms from different domains, however it is concluded that domain independent mechanisms need to be augmented with domain specific mechanisms to facilitate coordination. Part II is a review of design coordination from an operational perspective

    Matthew Scott & Joseph Hills: combined composition recital

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    Program order was changed during performance: Jane's Bistro was performed prior to Duet for Horn and Bass.Includes the recital program and seven audio recordings of compositions titled: Daglarim, I Often Wondered, Ulterior Motives, Concerto for Saxophone Quartet - 1: Dance, Jane's Bistro, Duet for Horn and Bass, Mirrors. Performed at 4:30 pm on March 26th, 2010, at Organ Recital Hall, University Center of the Arts, Colorado State University, Fort Collins, CO
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