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1.
Improving Systems by Combining Axiomatic Design, Quality Control Tools and Designed Experiments 总被引:2,自引:0,他引:2
Fredrik Engelhardt 《Research in Engineering Design》2000,12(4):204-219
This paper presents an approach for solving design problems in existing designs. A design analysis with Axiomatic Design,
called Design Object Analysis, describes a product or a system in terms of Customer Needs (CNs), Functional Requirements (FRs),
Design Parameters (DPs) and Process Variables (PVs), as well as their associated Design Matrices (DMs). In this paper, the
design analysis is combined with a thorough investigation of possible problems within the design, utilizing the seven quality
tools, noise factor analysis, and designed experiments to form an approach for quality improvements and problem solving. The
Design Object Analysis helps secure valid input-factors to the designed experiments, and the designed experiments correct
or improve the assumptions made in the Design Object Analysis. Thus, a combination of product modeling by Axiomatic Design
and designed experiments overcomes shortcomings of the two methods. The benefits of performing a Design Object Analysis, as
compared to other methods, become clear when it comes to evaluating the results from the designed experiment, and preventing the problem. Once the critical parameters are confirmed, and the design matrices are updated, suggested design improvements
can then be checked against the design matrices, and the system effect of a design-change-order can be estimated. The approach
described in this paper was successfully applied and verified in a case study at a large automotive company. 相似文献
2.
Vincent François Jean Christophe Cuillie`re Michel Gueury 《Research in Engineering Design》1999,11(1):55-66
This paper presents a method to integrate in a better way the finite element method in the CAD/CAM process for two-dimensional
problems, through efficient and automatic meshing and remeshing procedures. During the design step, the lack of integration
between geometric modeling and numerical analysis remains a crucial problem and it still tends to restrain the use of finite
element methods to a small number of engineers. Here we tackle the problem of the automatic remeshing of an object in the
context of minor changes in its geometry and topology without restarting the mesh generation from the beginning. We have developed
a mesh generator that is able to adapt a previous mesh, through two complementary strategies (for 2D cases) to a new geometry
without destroying the whole initial discretization. We also present the possible extension of these concepts to three-dimensional
problems. 相似文献
3.
Abstract. In this paper we consider the problem of selecting optimal beam directions as well as optimal intensity profiles for radiation
therapy. Our multiobjective mixed integer programming problem is based on and extends a multiobjective LP formulation for
intensity optimisation by Hamacher and Küfer. We use a weighted sum scalarisation to explore the benefits of beam direction
optimisation. We propose exact and heuristic methods for solving the problem and present some numerical results.
Correspondence to: M. Ehrgott 相似文献
4.
Matthew I. Campbell Jonathan Cagan Kenneth Kotovsky 《Research in Engineering Design》1999,11(3):172-192
This paper provides an introduction to a new design methodology known as A-Design, which combines aspects of multi-objective
optimization, multi-agent systems, and automated design synthesis. The A-Design theory is founded on the notion that engineering
design occurs in interaction with an ever-changing environment, and therefore computer tools developed to aid in the design
process should be adaptive to these changes. In this paper, A-Design is introduced along with some simple test problems to
demonstrate the capabilities of different aspects of the theory. The theory of A-Design is then shown as the basis for a design
tool that adaptively creates electro-mechanical configuration designs for changing user preferences. 相似文献
5.
This paper outlines the development of an effective and consistent ‘designing-in-quality’ strategy that can be used to deal
with concepts of uncertainty, quality and robustness in engineering design. Specifically, this paper presents a decision analysis-based
robust design metric that seamlessly integrates objective evaluations on the goodness of a design alternative with the designer’s
intent and preferences. This is achieved through the development of a set of performance-reflecting dominance indices for
the attributes and their utilization in a preference-influenced multiattribute utility formulation. Such a knowledge feedback-based
decision model development will be particularly useful when dealing with complex iteration-based engineering design process
where little information on the expected outcomes may be known a priori, or where product performance is computationally expensive to evaluate. Application of this robust design metric in a multi-stage
experimentation and modeling design process is presented. The characteristics of the proposed design metric and the effectiveness
of the overall design procedure in dealing with constrained engineering design problems are examined with the aid of demonstrative
case studies and the results are discussed. 相似文献
6.
Computing the Information Content of Decoupled Designs 总被引:1,自引:1,他引:0
The information content of uncoupled designs can be computed by summing the information content associated with each functional
requirement. This paper proves that information cannot be summed for decoupled designs. To overcome this problem, this paper
presents two algorithms for computing information content of decoupled designs. One algorithm is applicable to any joint probability
density function for the design parameters; the second algorithm applies only to uniformly distributed design parameters.
The algorithm for uniform distributions is based on a recursive procedure for computing the volume of a convex polytope in
n
-dimensional real space, where
n
is the number of design parameters. An engineering application of the algorithms is presented. The example demonstrates that
summing information content can significantly over-estimate total information when compared to an algorithm that accounts
for correlation. The example also demonstrates that decoupled designs can have lower information content than uncoupled systems
with the same functional requirements and similar components. 相似文献
7.
A scheduling method for Berth and Quay cranes 总被引:12,自引:2,他引:10
This paper discusses a method for scheduling Berth and Quay cranes, which are critical resources in port container terminals.
An integer programming model is formulated by considering various practical constraints. A two-phase solution procedure is
suggested for solving the mathematical model. The first phase determines the Berthing position and time of each vessel as
well as the number of cranes assigned to each vessel at each time segment. The subgradient optimization technique is applied
to obtain a near-optimal solution of the first phase. In the second phase, a detailed schedule for each Quay crane is constructed
based on the solution found from the first phase. The dynamic programming technique is applied to solve the problem of the
second phase. A numerical experiment was conducted to test the performance of the suggested algorithms.
RID="*"
ID="*" This research has been supported in part by Brain Korea 21 Program (1999–2002).
Correspondence to: Y.-M. Park 相似文献
8.
A characteristic of the design process in all areas of design is the use of a number of different types of drawings. The different types of drawings are associated with different stages of the process with one type, the relatively unstructured and ambiguous sketch, occurring early in the process. Designers place great emphasis on the sketch often because it is thought to be associated with innovation and creativity. Because of this emphasis researchers have also begun to focus on the sketch and its role in design. The first aim of this paper is to collect together and review the results of this research and to relate it to similar research that has looked at the role of drawings in problem solving in other disciplines. Recently, however, researchers in the design area have begun to relate their work to a number of areas of research in cognitive psychology and cognitive science. This work provides theoretical frameworks, experimental methodologies and a considerable body of research results that are of great potential importance to design research. The second aim of this paper is to review three of these areas, working memory, imagery reinterpretation and mental synthesis, and to examine their implications for design research generally but with a particular emphasis on the role of sketching in design. 相似文献
9.
During engineering processes, many kinds and amounts of information are used and produced. Such information is useful in successive
cases, and thus its reuse is desired. In this paper, information on attributes of the products is referred to as ‘product
information’, and information on the reasons for and/or history of a designer’s thought process is referred to as ‘process
information’. According to this classification, process information can be used for obtaining an explanation of product information.
The purpose of this work is to build a database, called an ‘engineering history base’, from which engineers can retrieve explanations
to enable the reuse of product information. In this paper, explanation from the ‘process’ viewpoint is thought to be important
in promoting the reuse of product information. There are two types of explanation for the process: teleological and causal.
However, until now, little attention has been paid to the causal explanation for the process. Thus, in this paper, an information
model which focuses on both types of explanation is proposed. The model is adopted for the engineering history base and a
prototype system is developed. The appropriateness of this model is discussed by analyzing the actual data in the development
of a color video printer. 相似文献
10.
Beth Adelson 《Research in Engineering Design》1999,11(3):133-144
This work applies a theory-based framework of collaborative negotiation to some of the disputes that regularly arise during
group design. Although the framework was developed to provide general support for group work, this paper focuses on its use
as a design tool. The framework, embodied in our system NegotiationLens, has four facets. It:
1. Provides a negotiation method intended to produce gain for all parties.
2. Provides an efficient process for conflict resolution.
3. Develops working alliances.
4. Lets parties decide quickly when they should go their separate ways.
The framework produces the above results by:
• Helping parties develop well-reasoned and clearly articulated points of view (Adelson and Jordan, 1991; Conklin and Yakemovic,
1991; Conklin and Begeman, 1988; MacLean
et al
., 1991).
• Creating a context of committment and respect.
• Moving negotiating parties away from an adversarial stance and into a collaboration.
• Allowing joint construction of solutions that are more beneficial than the unilateral solutions each party initially brought
to the table.
We present our framework for collaborative negotiation, describe NegotiationLens, and present two cases in which it was used.
We present a third case, a large design project with recurrent design conflicts, and argue how NegotiationLens could have
been of benefit there. 相似文献
11.
A Theory of Complexity, Periodicity and the Design Axioms 总被引:2,自引:1,他引:1
Nam P. Suh 《Research in Engineering Design》1999,11(2):116-132
One of the topics that has received the attention of mathematicians, scientists and engineers is the notion of complexity.
The subject is still being debated, as it lacks a common definition of complexity, concrete theories that can predict complex
phenomena, and the mathematical tools that can deal with problems involving complexity. In axiomatic design, complexity is
defined only when specific functional requirements or the exact nature of the query are defined. Complexity is defined as
a measure of uncertainty in achieving a set of specific functions or functional requirements. Complexity is related to information,
which is defined in terms of the probability of success of achieving the Functional Requirements (FRs). There are two classes
of complexity: time-dependent complexity and time-independent complexity. There are two orthogonal components of time-independent
complexity, i.e., real complexity and imaginary complexity. The vector sum is called absolute complexity. Real complexity of coupled design is larger than that of uncoupled or decoupled designs. Imaginary complexity can be reduced
when the design matrix is known. As an example of time-independent imaginary complexity, the design of a printing machine
based on xerography is discussed. There are two kinds of time-dependent real complexity: time-dependent combinatorial complexity and time-dependent periodic complexity. Using a robot-scheduling problem as an example, it is shown that a coupled design with a combinatorial complexity can be
reduced to a decoupled design with periodic complexity. The introduction of periodicity simplifies the design by making it
deterministic, which requires much less information. Whenever a combinatorial complexity is converted to a periodic complexity,
complexity and uncertainty is reduced and design simplified. 相似文献
12.
To obtain a better understanding of how to make use of functional materials in engineering design, the design-related behaviors
of some of these materials have been analyzed and discussed with reference to a general design procedure model and the design
tools currently available. The functional materials subjected to this examination are shape memory alloys, piezoelectric materials
and magnetostrictive materials. The discussion has been carried out with a major focus on how benefits might be gained by
selecting the functional material and utilizing complementary design tools at an early stage of the design process. 相似文献
13.
14.
Serdar Tumkor 《Research in Engineering Design》2000,12(3):163-171
The Internet and World Wide Web (WWW) are evolving as an important communication technology. This paper examines the development
of an Internet-based online catalogue on the WWW. An interactive website is prepared that helps a remote designer to design
shafts and bearings based on various input parameters provided. The web site also provides solid models of the shaft to perform
CAD and FEM analysis. This permits the user to make further investigations, and helps to modify the design satisfactory. 相似文献
15.
Graham Coates Robert Ian Whitfield Alex H. B. Duffy Bill Hills 《Research in Engineering Design》2000,12(2):73-89
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. 相似文献
16.
Strategic technology investment under uncertainty 总被引:7,自引:0,他引:7
In this paper the technology investment decision of a firm is analyzed, while competition on the output market is explicitly
taken into account. Technology choice is irreversible and the firms face a stochastic innovation process with uncertainty
about the speed of arrival of new technologies. The innovation process is exogenous to the firms. For reasons of market saturation
and the fact that more modern technologies are invented as time passes, the demand for a given technology decreases over time.
This implies that also the sunk cost investment of each technology decreases over time.
The investment decision problem is transformed into a timing game, in which the waiting curve is introduced as a new concopt.
An algorithm is designed for solving this (more) general timing game. The algorithm is applied to an information technology
investment problem. The most likely outcome exhibits diffusion with equfal payoffs for the firms.
Received: December 16, 1999 / Accepted: February 7, 2001 相似文献
17.
Robert Ian Whitfield Graham Coates Alex H. B. Duffy Bill Hills 《Research in Engineering Design》2000,12(1):48-60
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. 相似文献
18.
Structure and Matrix Models for Tolerance Analysis from Configuration to Detail Design 总被引:8,自引:0,他引:8
A substantial amount of all quality problems that arise during assembly can be referred back to the geometrical design, and
especially the geometrical concept of the product, i.e. the way in which parts are designed and located with each other. Special
emphasis should thus be put on geometry design, especially during the early design phases, to try to find robust concepts
and avoid solutions that may cause down-stream production problems.
This paper presents a generic set of evaluation tools for robust geometry design encountering (i) potential tolerance chain
detection in configuration design, (ii) assembly robustness evaluation in concept design, and (iii) tolerance sensitivity
analysis in detail design. Special attention is given to the development of a new matrix-based evaluation tool for the configuration
design part. The tool presented is based on a new way of representing geometry variation constraints in an enhanced function-means
tree structure model. Different parts of the function-means tree that are of interest for analysis purposes are then extracted
and converted to matrix representation. The reason for doing this is that the structure model is most suitable for modeling,
but becomes unsuitable for analysis as the model complexity increases. For this latter purpose, the matrix representation
is far better. The use of the different tools is demonstrated in the design of a new vehicle front system for which the geometry
a priori
is unknown. 相似文献
19.
Polymer processes are in general difficult to model, especially because of coupling between process conditions, polymeric
behaviors and geometries. Arising from high thermal gradients, non-Newtonian viscous behaviors and non-linear pressure effects,
polymer processing is not well described mathematically. A conceptual design methodology is proposed formally as a useful
tool for treating polymeric processes with multiple performance parameters on a structured design platform. Without resorting
to engineering models, this approach deals with the initial selection of process conditions within a three-stage framework:
(1) qualitative design; (2) process modeling; and (3) quantitative design. Based on subjective reasoning, this procedure makes
it possible to account for one’s prior experience, and incorporate it into the process development. The notion of conceptual
robutstness is introduced to ensure deesign quality in the early-stage process development. A case study of compression molding
is illustrated in a step-by-step manner. 相似文献
20.
Karl-Heinz Küfer Alexander Scherrer Michael Monz Fernando Alonso Hans Trinkaus Thomas Bortfeld Christian Thieke 《OR Spectrum》2003,25(2):223-249
Abstract. Radiation therapy planning is often a tight rope walk between dangerous insufficient dose in the target volume and life threatening
overdosing of organs at risk. Finding ideal balances between these inherently contradictory goals challenges dosimetrists
and physicians in their daily practice. Todays inverse planning systems calculate treatment plans based on a single evaluation
function that measures the quality of a radiation treatment plan. Unfortunately, such a one dimensional approach cannot satisfactorily
map the different backgrounds of physicians and the patient dependent necessities. So, too often a time consuming iterative
optimization process between evaluation of the dose distribution and redefinition of the evaluation function is needed. In
this paper we propose a generic multi-criteria approach based on Pareto's solution concept. For each entity of interest –
target volume or organ at risk – a structure dependent evaluation function is defined measuring deviations from ideal doses
that are calculated from statistical functions. A reasonable bunch of clinically meaningful Pareto optimal solutions are stored
in a data base, which can be interactively searched by physicians. The system guarantees dynamic planning as well as the discussion
of tradeoffs between different entities. Mathematically, we model the inverse problem as a multi-criteria linear programming
problem. Because of the large scale nature of the problem it is not possible to solve the problem in a 3D-setting without
adaptive reduction by appropriate approximation schemes. Our approach is twofold: First, the discretization of the continuous
problem results from an adaptive hierarchical clustering process which is used for a local refinement of constraints during
the optimization procedure. Second, the set of Pareto optimal solutions is approximated by an adaptive grid of representatives
that are found by a hybrid process of calculating extreme compromises and interpolation methods.
Correspondence to: K.-H. Küfer 相似文献