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An analytical method is studied for estimating coupling between arbitrarily directed multiple finite-length lines with different line lengths and heights. Coupling or crosstalk analysis is performed by developing an expanded circuit-concept approach based on modified telegrapher's equations of the Agrawal approach instead of the Taylor approach, providing some computational advantages. An electric image method using the quasi-static terms of the accurate Green's function is used to estimate the electromagnetic fields in an inhomogeneous medium such as a printed circuit board. The approach is applied to the analysis of parallel and nonparallel or bent microstrip models, and embedded-line models in which one line is embedded and the other is on the surface layer. To verify the proposed approach, we conducted some experiments and compared the results of our approach with the results of measurements and a commercial electromagnetic solver.

In the highly competitive marketplace, customer satisfaction is one of the critical success factors to many leading companies. Quality function deployment (QFD) has been regarded as a powerful customer-oriented design tool for developing new or improved products to achieve higher customer satisfaction by integrating various functions of an organization. In the QFD process, correctly rating the importance of customer requirements (CRs) is a crucial and essential step since it largely affects the target value setting of design requirements (DRs). This paper proposes a novel approach to prioritize CRs from the viewpoint of company’s competitiveness (i.e., competitive priority ratings). The key characteristic of proposed approach is to model the customer’s preference structure as the form of customer satisfaction function by combining the competitive benchmarking analysis with Kano’s analysis. Finally, the proposed approach is illustrated with a numerical example of car door design problem.

Handling uncertainties at the early phase of design is of great importance for front-loading product development. Designers often have preferences for design parameters of a design object even if they include uncertain information. The present study proposes a new set-based design approach for the early phase of design that intrinsically contains various sources of uncertainties. The proposed design approach, a preference set-based design PSD method, obtains a ranged set of feasible design solutions while incorporating the designer's preference for design parameters represented as preference functions instead of a single-point solution under design uncertainties by eliminating infeasible and inferior subsets of solutions. The present study applies the PSD method to a material design problem of a multilayer sound absorption/insulator including porous material. It is difficult to predict the performance because of a number of design parameters such as Biot parameters i.e. porosity, density, tortuosity, flow resistivity, viscous characteristic length, loss factor and Poisson's ratio of a material and production tolerance. We develop a performance prediction system based on the PSD method that can obtain the ranged set of design solutions that satisfy the ranged sets of performance requirements through set-to-set space mapping from design space to performance space and space narrowing to eliminate infeasible design subspaces. Through the application of design of the material design problem, the advantages of the PSD method for obtaining the multi-objective solution under design uncertainties toward front-loading product development are discussed.

Quality function deployment (QFD) has gained extensive international support as one of the powerful techniques to achieve higher customer satisfaction. In the QFD, correctly rating the final importance of customer requirements (CRs) is a crucial and essential process since it largely affects the target value setting of design requirements (DRs). The final importance ratings of CRs are generally determined by combining relative importance ratings (RIRs) and competitive priority ratings (CPRs). This paper proposes a new method to obtain the CPRs of CRs during the QFD process. The proposed CPR method constructs the customer satisfaction model based on the competitive benchmarking analysis and then evaluates the performance quality of company product using the author’s satisfaction and uncertainty measure. Furthermore, the CPR method is integrated with the Kano’s model to capture the different impacts of CRs on customer satisfaction. Finally, the proposed CPR method is illustrated with a numerical example of car door design problem.

The advancement of computer networks and information technologies has been rapidly changing the manufacturing environment of the industrial age to that of the current information era. The engineering philosophy has been shifted from concurrent engineering to collaborative engineering among the respective areas of expertise in a design space. Handling uncertainties in an initial design process is of great importance, particularly for collaborative engineering. For collaborative engineering, designers having different preferences in the different disciplines need to represent their own possible design solutions or design solution spaces, and they also need to understand the other designers’ design solution spaces. We have proposed a preference set-based design method that enables a flexible and robust design under various sources of uncertainties, while capturing a designer’s preference. In this study, the proposed method was applied to a real industrial multi-objective design problem (i.e. an automotive front-side frame design). This study discusses the suitability of our proposed approach for obtaining the multi-objective satisfactory solutions that reflect the different design preferences of different designers in their design solutions for collaborative engineering.

Customer satisfaction is one of the critical success factors to many leading companies over the world. Quality function deployment (QFD) has gained extensive international support as one of the powerful techniques to increase the customer satisfaction. In the QFD, correctly rating the final importance of customer requirements (CRs) is a crucial and essential process since it largely affects the target value setting of design requirements. The final importance ratings of CRs are generally determined by combining relative importance ratings and competitive priority ratings. However, determining the final importance ratings is very difficult due to the typical uncertainty or imprecision of customer’s judgment (or perceptions). This paper proposes a novel approach to prioritize CRs in QFD process by developing two sets of new rating methods, called customer preference rating (CPR) method and customer satisfaction rating (CSR) method, for relative importance ratings and competitive priority ratings, respectively. The CPR method provides a simple and intuitive technique to capture the customers’ incomplete or uncertain perceptions on the relative importance of CRs based on their own preferences, allowing them to give a partial ordering of CRs. The CSR method constructs the customer satisfaction model based on the competitive benchmarking analysis and then evaluates the performance quality of company product using our satisfaction and uncertainty measure. Furthermore, the CSR method is integrated with the Kano’s model to capture the different impacts of CRs on customer satisfaction. Finally, the proposed approach is illustrated with a numerical example of car door design problem.

Two-dimensional compressible momentum and energy equations with slip boundary conditions are solved to obtain the heat transfer characteristics of gaseous slip flow in a micro-channel with CWT (constant wall temperature) whose temperature is lower or higher than the inlet temperature (cooled case or heated case). The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The stagnation temperature is fixed at 300 K and the computations were done for the wall temperature which ranges from 250 K to 350 K. The channel height ranges from 2 to 10 μm and the channel aspect ratio is 200. The stagnation pressure is chosen in such a way that the exit Mach number ranges from 0.1 to 0.7. The outlet pressure is fixed at atmospheric condition. The bulk temperature and the total temperature of the heated case are compared with those of the cooled case and also compared with temperatures of the incompressible flow in a conventional sized channel. Heat transfer characteristics of the gaseous flow are different from those of the liquid flow. And they are also different from each cooled and heated case. A correlation for the prediction of the heat transfer rate of the gaseous slip flow in a micro-channel is proposed.

Various computer-based simulation tools such as 3D-CAD systems and CAE are widely used to design products at the early phase of design. Designers must search the optimal solution that satisfies a number of performance requirements by repeating analysis and modification of the CAD models. They need to confirm the results of CAE analysis until they can obtain a better design solution. These works impose a heavy burden on designers and analysts. Therefore, design works can be more efficient if we can automate these iterative processes. Moreover, the early phase of design contains multiple sources of uncertainty in describing design, and nevertheless the decision-making process at this phase exerts a critical effect upon drawing a successful design. Therefore, handling the uncertainties in the early phase of design has great importance especially for concurrent engineering (CE). The previous series of our studies have proposed a preference set-based design (PSD) method that enables the flexible and robust design while incorporating designer’s preference structure. In contrast to conventional optimization techniques, this method generates a ranged set of design solutions that satisfy sets of performance requirements. The combination of 3D-CAD and CAE with PSD method can be more powerful design support system. In this study, a system based on PSD method is implemented by combination of 3D-CAD and CAE, and a design example of a swing arm is demonstrated to show the effectiveness of the proposed system for obtaining the multi-objective satisfactory solutions reflecting the designers’ intentions.

So far, there has been an extraordinary development of computer-aided tools intended to generate, present or communicate 3D models. But there has not been a comparable progress in the development of 3D-CAD systems intended to assist designers in representing and manipulating both geometric and non-geometric design information based on solid models, thus facilitating concurrent engineering (CE). Design objects continue to be produced by traditional means using the computer as little more than a drafting tool. In addition, the state-of-the-art 3D-CAD systems are incapable of encoding engineering uncertainties since only precise single-valued assignments are allowed for their modeling operations. Recently, set-based CE (SBCE) has been attracting public attention as an emerging CE paradigm. Such a set-based design (SBD) approach presents many possibilities in handling the uncertainties that are intrinsic at the early phases of design. This paper addresses a novel concept – set-based parametric design (SBPD) – which combines the SBD practice with the parametric modeling technique widely used in most 3D-CAD systems. A preference set-based design (PSD) model and a design information solid (DIS) model are proposed to incorporate the SBPD concept into the current 3D-CAD systems. Finally, a prototype system is implemented to illustrate the potential to achieve a SBPD practice.

The early phase of design intrinsically contains multiple sources of uncertainties in describing the design, and nevertheless the decision-making process at this phase exerts a critical effect upon drawing a successful design. Recently, set-based concurrent engineering (SBCE) has been attracting public attention as an emerging CE paradigm. Representing and communicating set-valued information are useful in handling engineering uncertainties and efficient for the collaboration between designers in the CE environment. Even if we can readily know that SBCE is efficient and powerful enough for large-scale design and management, the existing literature does not give the details of methods to achieve SBCE principles. We have developed a computer-based framework, called ‘preference set-based design’ (PSD), for implementing SBCE principles, which consists of set representation, propagation, modification, narrowing, and aggregation methods. This article focuses on the set representation and aggregation methods that play an important role in the CE environment. This article proposes new engineering quantities that can capture the designer’s preference structure on both the continuous and the discrete sets. A new aggregation method is presented to aggregate the proposed engineering quantities. A comparative analysis with the existing representation and aggregation techniques is also provided.

Concurrent engineering (CE) has been widely accepted as an effective engineering practice for decreasing product development time, improving quality, decreasing manufacturing costs, and improving customer satisfaction. Since CE philosophy is intended to consider all elements of product life cycle from the outset, CE approach increases the complexity of design problem and makes it more difficult to manage. In addition, the advances in computer networks and information technology have brought engineering design into a new era. Although a considerable number of studies have been made on design decomposition (e.g., product and process (or perspective) decomposition) as a means to reduce the complexity of a large scale design problem, relatively little attention has been given to the computational framework for dynamic and systematic design integration in a computer network-oriented design environment. This paper describes an integrated product and process modeling (IPPM) framework for collaborative product design through the Internet. Here, the hierarchical and heterarchical dependencies between the decomposed smaller design problems are addressed. An agent-based approach is proposed for the computer support of hierarchical and heterarchical design topologies. In our framework, a smaller design problem is dynamically modeled in terms of interacting and pluggable design agents that represent a specific aspect of the design problem and provide the interoperability between heterogeneous design agents or software applications, and the results of these smaller problems are recursively integrated to formulate solutions to the larger problems in a systematic manner. Finally, the proposed framework forms a global design network through which a number of design possibilities are explored.

There are a large number of uncertainties of the design variables and the requirements while the decision-making process at the early phase of design has the greatest effect upon the lead time of development and the overall cost. Designers need to figure out an outline of the structural feature and have to compare the evaluation results of diverse design ideas from multiple aspects under some uncertain design information at the early phase of structural design. We have proposed a preference set-based design (PSD) method that generates a ranged set of design solutions that satisfy sets of performance requirements. This study proposes a decision-making support method for the early phase of structural design based on the PSD method that is possible to analyze, obtain and compare diverse design ideas with design uncertainty and variability by elastic FEM. We apply the proposed method to a structural form of a bridge with uncertainties of cross-section area of members and dimension of structure (coordinates of geometry) under fluctuating distribution of performance characteristics of the maximum stress and the mass.

A satisfactory multiobjective design that incorporates physical performance as well as sustainability is necessary from a global environmental protection perspective. For obtaining sustainable lifecycles, decision making in the early phases of the design process, considering multiple sources of uncertainty, is important. Previously, we proposed a preference set-based design (PSD) by Inoue et al. (2010) [16] method, which enables a flexible and robust design under various sources of uncertainty while capturing the designer's preference based on his/her knowledge or experience. The present study focuses on a decision-making support for sustainable product creation in the early phases of the design process considering the various design uncertainties. We investigate different officially accepted sustainability indicators and identify the ones that are related to the product development process by considering the physical performance and sustainability of the products concurrently. Thereafter, the proposed method is applied to a multiobjective design problem. This paper discusses the applicability of PSD as a decision-making support method for sustainable development using the design of an alternator as an example.

With worsening environmental problems such as the depletion of natural resources and global warming, environmentally conscious design is required. This paper proposes an methodology of upgrade design of product for environmentally conscious design based on the concept of set-based design. Usually the prediction of upgrade performance or upgrade-time would have uncertainties caused by the future situation of design. So there are some possibilities that the upgrading will affect geometry of the target module, performance of non-target modules, cost, life and environmental load of product. And also, upgrade design problem requires multi-objective evaluation of those various design items about target modules and non-target modules while handling the uncertainties. In our previous study, we propose a preference set-based design (PSD) method that can obtain a ranged set of design solutions that satisfies multiple performance requirements concurrently such as physical performance, environmental indication, and cost by representing uncertain design information as ranged sets with designer’s intention. This study proposes the fundamental concept and a concrete method for upgrade design based on PSD method, and then we obtain design solutions of product by a predicted range of upgrade performance. The proposed method applies to robot arm design and we obtain multi-objective ranged solutions of the design, which satisfies predicted range of upgrade performance, including environmental issue. Finally, we discuss the availability of the proposed PSD method for upgrade design with uncertainty and environmental issues by evaluating multi-objective items including product performance and environmental load by upgrade.

The advancement in computer networks and information technologies has been rapidly changing the manufacturing environment from the environment in industrial age to it in information era. The engineering philosophy has been shifted from concurrent engineering to collaborative engineering among the respective areas of expertise in the design space. Handling the uncertainties in the initial design has a great importance especially for the collaborative engineering. Due to the complexity of today’s products and the incorporated overlapping activities between the lifecycle functions, the multi-objective optimized design is necessary. We have proposed a preference set-based design method that enables the flexible and robust design under various sources of uncertainties while capturing designer’s preference. This paper discusses the availability of our proposal for obtaining the multi-objective satisfactory solution in the collaborative engineering by applying to an automotive front-side frame and a material design problem of multilayer porous absorber and insulator.