THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

House of Quality

Product design is a highly involved, often ill-defined, complex and iterative process, and the needs and specifications of the required artifact get more refined only as the design process moves toward its goal. An effective computer support tool that helps the designer make better-informed decisions requires efficient knowledge representation schemes. In today's world, there is a virtual explosion in the amount of raw data available to the designer, and knowledge representation is critical in order to sift through this data and make sense of it. In addition, the need to stay competitive has shrunk product development time through the use of simultaneous and collaborative design processes, which depend on effective transfer of knowledge between teams. Finally, the awareness that decisions made early in the design process have a higher impact in terms of energy, cost, and sustainability, has resulted in the need to project knowledge typically required in the later stages of design to the earlier stages. Research in design rationale systems, product families, systems engineering, and ontology engineering has sought to capture knowledge from earlier product design decisions, from the breakdown of product functions and associated physical features, and from customer requirements and feedback reports. VR (Virtual reality) systems and multidisciplinary modeling have enabled the simulation of scenarios in the manufacture, assembly, and use of the product. This has helped capture vital knowledge from these stages of the product life and use it in design validation and testing. While there have been considerable and significant developments in knowledge capture and representation in product design, it is useful to sometimes review our position in the area, study the evolution of research in product design, and from past and current trends, try and foresee future developments. The goal of this paper is thus to review both our understanding of the field and the support tools that exist for the purpose, and identify the trends and possible directions research can evolve in the future.

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The evolution, challenges, and future of knowledge representation in product design systems

This paper provides a detailed review of the state of the art in product cost estimation covering various techniques and methodologies developed over the years. The overall work is categorized into qualitative and quantitative techniques. The qualitative techniques are further subdivided into intuitive and analogical techniques, and the quantitative ones into parametric and analytical techniques. Each of the techniques is then described and discussed, in detail, with further subdivisions. The paper also signifies the importance of cost estimation in the early phases of the design cycle and, as such, briefly discusses the current trends and future directions in the area. Research work carried out in the field with reference to specific applications is also reviewed. The paper provides a comprehensive literature review in the field and should be useful to researchers and practitioners interested in this field.

Product Cost Estimation: Technique Classification and Methodology Review

Correlation and causality

This paper describes a method for modelling costs throughout the design phase of a product's life-cycle, from conceptual to detail design. The timely provision of cost data facilitates the quantitative evaluation of designs through a cost function. This approach to design evaluation has the advantages of allowing management to make more accurate bid estimates, encouraging designers to design to cost and reducing the amount of design rework, hence reducing the product's time to market and controlling product cost. The cost modelling strategy adopted incorporates the use of knowledge-based and case-based approaches. Cost estimation is automated by linking design knowledge, required for predicting design features from incomplete design descriptions, to production knowledge. The link between the two knowledge paradigms is achieved through the blackboard framework of problem solving, which incorporates both case-based and rule-based reasoning. The method described is aimed at innovative design activity.

A methodology for modelling manufacturing costs at conceptual design

This paper presents a novel CAD feature recognition approach for thin-walled injection moulded and cast parts in which moulding features are recognised from a mid-surface abstraction of the part geometry. The motivation for the research has been to develop techniques to help designers of moulded parts to incorporate manufacturing considerations into their designs early in the design process. The main contribution of the research has been the development of an attributed mid-surface adjacency graph to represent the mid-surface topology and geometry, and a feature recognition methodology for moulding features. The conclusion of the research is that the mid-surface representation provides a better basis for feature recognition for moulded parts than a B-REP solid model. A demonstrator that is able to identify ribs, buttresses, bosses, holes and wall junctions has been developed using C++, with data exchange to the CAD system implemented using ISO 10303 STEP. The demonstrator uses a commercial algorithm (I-DEAS) to create the mid-surface representation, but the feature recognition approach is generic and could be applied to any mid-surface abstraction. The software has been tested on a range of simple moulded parts and found to give good results.

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Graph-based feature recognition for injection moulding based on a mid-surface approach

This article describes research work which was directed towards providing the automotive industry with a practical methodology that translates the conceptual ideas of knowledge management (KM) into a working programme with defined objectives, using industry terminology. The research also developed a supporting analysis methodology that enables an effective analysis of the influences on employee activities when creating and sharing valuable corporate knowledge, that spans technical and cultural boundaries. This happens through identifying the factors that impact on defined KM metrics. The analysis identifies the key influencing factors within a working environment. The research benefits are felt when the ground‐level drivers of KM behaviour are improved through links to an appropriate KM strategy. KM strategy may emphasise organisational cultural changes or IT changes or both in an endeavour to improve innovation, reduce business costs and reduce time to market of new products. An industrial case study was undertaken to validate the research.

A methodology for knowledge management implementation

Starting from a comparative study of various methods for uncertainty propagation, this paper presents a novel reduced quadrature technique to be used in gradient-based robust design optimization of aerodynamic shapes. The accuracy and computational efficiency of the method are investigated by means of mathematical analyses and numerical examples. The method is then applied to the robust design of airfoils under probabilistic uncertainty. It is shown that the solutions obtained through the proposed method can outperform those obtained through linearization, without any significant increase in computational cost.

Novel Uncertainty Propagation Method for Robust Aerodynamic Design

Parameterization has a significant role in airfoil design and optimization where, especially in the early design stages, the aim is to be able to explore as many design alternatives as possible while keeping the number of design parameters to a minimum. Several desirable characteristics, namely, Parsimony, Intuitiveness, Orthogonality, Completeness and Flawlessness are considered. These are applied as comparison metrics to five airfoil parameterization techniques: Ferguson’s curves, HicksHenne bump functions, B-Splines, PARSEC, and Class/Shape function Transformation. The method allows each parameterization technique to be ranked according to each criterion considered, thus providing a basis for objective multiple criteria decision making.

Marin D. Guenov

Papers

A methodology for modelling manufacturing costs at conceptual design

Graph-based feature recognition for injection moulding based on a mid-surface approach

A methodology for knowledge management implementation

Novel Uncertainty Propagation Method for Robust Aerodynamic Design

A Comparison of Airfoil Shape Parameterization Techniques for Early Design Optimization