Four-wheel vehicle is known to be a nonhoronomic system. It is difficult to design a controller for this class of system. Nonhoronomic systems are required time-varying control or discontinuous control. However, it is difficult to design them theoretically. In this paper, we propose a control method for a four-wheel vehicle using a time-varying controller. The system parameters as the coefficients of the control gains are determined by GA optimization.

View full abstract

Solar collector is an equipment to absorb solar energy. Absorbed solar energy is used for hot water supply and floor heating by transforming to thermal energy. It is necessary to reduce the radiant thermal loss from absorber plates to improve the efficiency of solar collector. Reducing the radiant thermal loss lead to reduction of the thickness and miniaturization of solar collector, and expansion of the usage. This paper reports the results of reducing the radiant thermal loss based on shape modification of the absorber plate.

View full abstract

In this paper we propose a neuro-controller (NC) for suppression of load swing with disturbance in a crane system rotaring around the vertical axis. As in a nonholonomic system, the traditional control method using a static continuous state feedback law cannot stabilize the load swing. It is necessary to design a time-varying feedback controller or a discontinuous feedback controller. Previous research had been successful in constructing the suppression controller of the load swing with a single initial rotation angle when disturbance appeared. In this paper, the performance of the NC optimized by genetic algorithm will be examined with three initial rotation angles.

View full abstract

In this paper, we focus on the suppression of load swing in a rotary crane system by using neuro-controller(NC). In our previous study, we succeeded in performing the simulation of suppressing the load swing in the rotary crane with system fluctuation by NC using bit-string genetic algorithm(BGA). However, this NC is still low generalization ability. Then, we try the study of NC for the rotary crane with system fluctuation using real-corded genetic algorithm(RGA). Simulation results show that RGA has higher control performance compared with BGA.

View full abstract

To design artifacts that make people's life and society wealthy in regard to both material and mind, it is necessary to consider not only their functions and performances but also other various factors which conventional engineering design does not necessarily cover such as emotion, feelings and aesthetics. In this paper, the authors describe their basic concept and trials of research and education aiming design innovation by engineering approach.

View full abstract

In usual design process with a three-dimensional CAD system, it is difficult to decide a shape, position and orientation, and motion of a design object simultaneously. Four-dimensional geometric modeling enables us to deal with a dynamic three-dimensional design object as a static object in a higher-order space of space-time extension. The authors have been developing a four-dimensional geometric modeling system which weaves four-dimensional mesh models from successive three-dimensional voxel models. This report presents discussion on how four-dimensional geometric modeling effects both the concept of design objects and design processes.

View full abstract

Robust design enables the products to ensure robust performance in diverse conditions due to increased individuation of user needs and the globalization of markets, and many robust design methods have been proposed. Conventional methods are applicable to design problem in which robustness is ensured by using unique control factor. However, these methods are not applicable to design problem in which robustness is guaranteed only by using a control factor that has an adjustable range or a multilevel. In the present study, a robust design method was proposed to derive the optimum adjustable range and optimum multilevel that enable users to adjust or choose to meet their needs. In the proposed method, first, the relation between the objective characteristic and the adjustable control factor is modeled using the robustness index or the weighted robustness index. The robustness index is to evaluate the feasibility of the objective characteristic value within the tolerance for all the values of the adjustable control factor. On the other hand, the weighted robustness index is added a weighted function to the robustness index, in order to estimate the importance of the objective characteristic value within the tolerance. Second, considering the characteristic of design problems, the optimum adjustable range or the optimum multilevel is derived by using three calculation methods based on two indices. We also applied the proposed method to two examples where the cushion angle of a public vehicle seat and the height of a public water fountain are determined.

View full abstract

While the design by the 20th century lived people's life rich, it also produced many negative legacies. In order to solve these problems produced by subdivision of a design, the new theory for the integration of each subdivided design is required. In the present study, based on the Multispace Design Model as one of design theory, a framework of design reasoning that describes three design acts of analysis, generation, and evaluation as induction, abduction, and deduction is proposed. Moreover, it is pointed out the importance of generation or evaluation based on analysis.

View full abstract

Function of an artifact and human Kansei are influenced by diverse conditions. First, this study shows the necessity of consideration of diverse conditions in design. Second, this study summarizes conditions of several areas of study and shows condition in design does not have viewpoint of conditions. Finally, In this study, experiments for beauty in the presence of a cast shadow or its position as a cognitive condition are conducted, and the relationship between evaluations and physical quantities is analyzed. In consequence, beauty is a variant of the presence of a shadow or its position and it is represented by the distance between the center of gravity of the sample and the shadow.

View full abstract

The Multispace Design Method based on the Multispace Design Model contains: Multispace Idea Generation Method, Multispace QFD and mathematical model. This Method can flexibly select characteristics of the analysis method and idea generation method, and freely apply these characteristics to the design process, enabling a continuous design process. However, applying this method to the product design showed two weaknesses: difficulty for users with industrial design knowledge to extract State space elements and adequate extraction of State elements. Therefore in this paper the Multispace Design Method was expanded by introducing a sketching process, and the expanded Multispace Design Method was applied to the design of a cleaning robot. Furthermore, the effects about the expansion were determined.

View full abstract

This paper has studied optimal opening diameter of aluminum beverage bottle with screw cap for openability. As a method of evaluation, we have defined the evaluation function of openability in terms of the ratio of the minimum gripping force required for opening cap to the maximum gripping force to hold the cap. Result from the optimization of the evaluation function of 10 subjects, the optima are obtained at around 30mm. Therefore, the dimension of opening diameter that is the best for whole subjects may exist at 30mm.

View full abstract

This paper has studied factors that affect consumer's feeling when opening and griping an aluminum beverage bottle, and suggests a method of evaluating opening and gripping ease. Gripping ease of three different kinds of shell diameters (φ50, φ60, φ70) has been evaluated by using semantic differential (SD) method of Kansei engineering. As a result, major subjects have evaluated that the shell diameters φ50 and φ60 is easier to grip than shell diameter φ70. On the other hand, opening ease of an aluminum beverage bottle has been evaluated by measuring grip force of unopened cap. Therefore, the diameter φ70 is the easiest to open than the other diameters.

View full abstract

The present report proposes an evaluation function of openability so as to evaluate opening ease of aluminum beverage bottles and to specify the rigorous dimension of cap diameter that is best suited for consumers' satisfaction. The evaluation function is defined as the ratio between the maximum torques that consumers can apply and the required torque for opening. In addition, the cap diameter is the only design variable, and the thumb length, which associates with the maximum gripping force, is selected as the state variable in order to take individual differences into consideration. Moreover, the function is formulated considering the uncertainty of opening actions of consumers. The function is composed by using the data obtained from the measurement of the maximum gripping force, the thumb length, and the opening actions, and then the function is optimized. The result of optimization shows that the optimum opening diameter is obtained at 30.6 mm. The thumb length associates with the maximum gripping force, and also affects the optimum opening diameter. The optimum opening diameter changes from 28 to 35 mm with the increase of the thumb length.

View full abstract

Product emotional quality consists of sensory information perceived through five senses by nature. Most conventional works in design for emotional quality have dealt with only one sense, e.g. a product color as a visual perception and a product sound as an auditory perception. There is an implicit assumption that the sensory information between different senses is independent in such works. However, sensory information of different sense may interact with each other. Sense of harmony between color and sound is an example of such interaction. In this paper, we discuss sense of harmony between product sound and product color as a product emotional quality based on experimental approach. We also discuss weights of each sense towards total emotional quality. We select a vacuum cleaner as case-study. We conduct two sensory tests based on SD method. In the first test, we show subjects multiple samples having different color and sound and ask them to evaluate them in terms of given emotional qualities. Using the result of the first test, we quantify the weights of each sense towards total evaluation of emotional quality and interaction between senses. In second test, we use evaluation samples that satisfy set design parameters of color and sound, in order to formulate the multi-modal emotional quantities. Based on the result of the test, we establish an assumption that sense of harmony between color and sound changes depends on sound sharpness, which is quantitative value of sound quality metrics. Using factor analysis, we found that the sharpness maximizing sense of harmony correlate with 2^<nd> factor of color, which is meaning sense of activity. We formulate the relation between 2^<nd> factor of color and design parameters of color and sound.

View full abstract

By means of the multiple interference phenomenon of light, window pane with optical multilayer coatings is able to control solar energy and the color through the window. It is important to design the color according to the user's own preferences for residential usage. On the other hand, the chromaticity diagram can indicate a specific color by using RGB values in the two-dimensional diagram. In this paper, the color of the outside view is designated by the chromaticity diagram. Furthermore the optimum structure of the multilayer coatings is designed to satisfy the user's sense of the color by the inverse analysis to identify the spectral transmission factor.

View full abstract

In designing a living environment, a quantitative evaluation of emotion is beneficial in improving emotional effects of users. In this study, we thought that the "comfortableness" of bathing activities can be quantitatively evaluated by capturing the continuous changes of physiological response along with the subjective evaluation. We captured the core temperature, skin temperature, and the heart rate of the subject as the physiological response. We conducted a spectral analysis of the variability of the heat rate. Finally, we examined the evaluation's effectiveness.

View full abstract

In the research of the sound quality of a classic guitar, the control of the vibration modes on the surface board is important. The envelope shape of the sound peak points on the frequency domain takes part in the tone color. The sound continuity is indicated by the damping wave shape. The glottal stop sound has the rapid by the diffusion of the vibration energy with creating the sound strongly. The unclear sound is caused by the lack of the high frequency sound amplitude. Here is the study for the behavior of the above sound qualities.

View full abstract

Recently, in increasingly fluctuating social conditions, construction of strong and continuous relationships with stakeholders is becoming more important for a business administration than ever. Although branding has emerged as a crucial measure to establish business continuity, there is difficulty implementing it in the design. This study intends to streamline connection between branding strategies and design activities. As an introductory paper of the study, Brand Equity Deployment which is QFD extension is introduced as a method to describe relationships between elements of the Customer-Based-Brand-Equity and design attributes. In addition, future extension of the study is discussed.

View full abstract

Up to now, engineering has focused its attention only upon how better quality products can be produced. But our customers are not mere consumers or users. They create many new ways of using our products. Therefore engineering tomorrow should focus more attention toward creative customers. And engineering should provide values not only in terms of final products, but also in the processes. So engineering tomorrow will create experience and value for our customers.

View full abstract

Recently the lathe skill tends to be lost because of aging experts, therefore personnel training has got more attention. Then, we developed the lathe processing skill transfer system for beginners that is used under virtual reality environment. The system detects the cutting condition while training of the operation. And the system presents the visual, force, and auditory sense depends on the cutting condition. We studied in demands of detail representation about sense of use the system, and consequence of showing sending speed of the tool bit on the vision. Then we discuss efficacy of the lathe skill transfer by comparison while on-the-job training.

View full abstract

This article shows our proposal educational method helped the beginner to learn how to mechanical design. The new curricula of Osaka prefectural college of technology reduced training time for professional education. In contrast, technical college student were required to learn highly practical expertise necessary in society. Then we provided new learning method for our student with digital engineering devices, which were 3D-CAD, rapid prototype device and 3D-digitizer.

View full abstract

As for the education in mechanical engineering, the idea and the process of the shape size decision is important. The design calculation support program has been developed for the engineering design and the drawing education. This program assists the teachers and the students. It was used to educate and the effectiveness of the program is discussed.

View full abstract

US, The Netherlands, Germany, etc are sending their students to such developing countries as Africa to support their self sustenance. The basic idea is to help the people over there to stand on their own feet. It is very much different from the idea of Japanese ODA, which ships very sophisticated technology and equipment to help them. In this presentation, these two types of supporting developing countries are compared and it is pointed out that Japan should go the same way as US, The Netherlands and Germany. It is also pointed out that Japanese industries should utilize university as these countries are doing and they would help them develop a new marker for them.

View full abstract

As compared with automobile, few train design methods for crashworthiness have been proposed. To establish it, we paid attention to double structure composed of train exterior and cabin, and designed train finite element model. We changed the position and thickness of steel plates joining these two constituents, and simulated train collision to a rigid body wall at the speed of 60 kilometer per hour. As a result of the optimization, it was shown that distortional energy in the cabin and maximum deceleration were reduced. We discussed relation of between absorbed energy and maximum deceleration, and introduced new train structure.

View full abstract

Aerodynamic characteristics of reusable observation vehicle are computationally investigated under subsonic and supersonic flows using the RANS (Reynolds-averaged Navier-Stokes) simulations. The initial investigation for the concept design is done with the light optimization using the light CFD. The results show that the simulations using coarse grid estimate the axial force coefficient and the lift to drag ratio accurately except some cases. The results indicate the correlation between the supersonic lift to drag ratio and the axial force coefficient. The results show the correlation between the y-coordinate of the design variable and the volume. The required knowledge for the concept design in the near future is obtained.

View full abstract

Multi-point aerodynamic optimization of a transonic wing using data mining is discussed. Design problem has two objectives which are minimization of drag coefficient at Mach number 0.6 and 0.8 respectively. Here, Mach number 0.6 is considered as a subsonic condition, and Mach number 0.8 is considered as a transonic condition with the local shock. To reduce the local shock that causes wave drag, the sweep back angle is required in transonic condition. On the other hand, the sweep back angle reduces lift to drag ratio in subsonic condition. Thus, a complex high lift device like a flap is required. Moreover, the torsion at wing root becomes stronger with high sweep back angle. As a result, the wing structure weight becomes heavy. To design high efficient new generation civil aircraft, the design knowledge which implements a subsonic and a transonic aerodynamic performance simultaneously with few structure penalty is expected. In this study, tapered wing geometry is defined with two cross sections. 31 sample designs are calculated by the unstructured Euler solver and Kriging surrogate models for the resulting drag coefficient of subsonic and transonic condition are constructed. Using these models, non-dominated solutions are obtained by genetic algorithm (GA). Analysis of variance (ANOVA) and Self-organized map (SOM), which are data mining techniques, are also applied to obtain the relationship between design space and solution space. According to this result, there is trade-off between two objective functions and compromised design can be considered. According to data mining result, there is possible to find the design which achieve low drag with low sweep back angle and contrived cross sections.

View full abstract

The finite element analysis has been performed for a double-skin hollowed structure by using the approximate equivalent stiffness. The equivalent stiffness for a plate is first given in the second-order polynomial form regarding the design variables by using the response surface method. Finite element analysis for a bending problem is formulated by using the ACM rectangular element, and then a code of finite element method is developed by incorporating the obtained equivalent stiffness. Finally the results acquired by using present method are compared with those acquired by using ANSYS as a commercials software to investigate the applicability of this method. Consequently, the present method can accurately estimate the equivalent stiffness.

View full abstract

The conceptualization of service is important for proper modeling of service. Aiming at an ontological conceptualization of service, we make an ontological consideration on distinction between notions of service and function. Firstly, we extract the characteristics of service from the literature in different disciplines in order to find out important characteristics of service. Next, we show many of them are not inherent characteristics in the notion of service. Then, we propose essential characteristics of services by comparison between service and function of artifacts based on a model of goal-oriented effects.

View full abstract

Service is attracting increasing attention as our economy matures. This paper discusses the approach and applicability of the service engineering method that the author has been working on. As this moment, the method is suitable for analyzing and designing contents and its delivery process of services that are to some extent stable at solving customer problems. Based on the above discussion, two new research issues to be studied are introduced in the paper: effect analysis on customer satisfaction in changing service contents; and detailed design of interactions with customer using machine learning.

View full abstract

In service engineering, contents parameters are very important for the customer service value. However, the contents parameters cannot be designed in any values, because the providers have limited resources, which are monetary and time, for the improvements of the contents parameters. In this study, we propose the method of the resource design with the represent of sigmoid functions and genetic algorithm. And, we verify the proposed method with a certain example.

View full abstract

As a hierarchical function structure model of a service, a view model has been proposed in Service Engineering. However, designers are apt to omit to describe necessary information when they construct a view model. Therefore, to prevent designers from omitting to describe important functions, it is necessary to enable to construct a view model from the viewpoint of service delivery processes. In this paper, the authors propose a method that extracts functions in a service from service delivery processes referring to function taxonomy. By using this proposed method, the consistency of a service is secured in service designs.

View full abstract

It is becoming more important for service providers to consider their customers as not only consumers but co-producers. In this paper, the function-attribute service model that authors have proposed is extended by introducing the concept of customer characteristics as co-producer. As a result, functions by customers, functions by provider, and their interactions are represented in the extended framework.

View full abstract

Scenarios are promising for drawing images of manufacturing industry in the sustainable society. Sustainable Society Scenario (3S) Simulator aims to support understanding, describing, and analyzing sustainability scenarios. To realize 3S Simulator, this paper proposes a method for describing structural scenarios by means of ontology. This method clarifies the logical structure of scenarios and facilitates scenario analysis. Examples illustrate that the proposed method clarifies the structure of a sub-scenario for a rational understanding, e.g., articulating rationales used for setting input data of a simulation. Also, what-if analysis by changing simulation assumptions in an original scenario is useful for discussing various futures.

View full abstract

This paper discusses the possibility of the integrated environmental optimality of a series of artifacts that are reconfigurable for gradually fluctuating demands by mutually replacing their subsystems. Following general discussion, leading design of home-use cogeneration systems is explored with the optimal design techniques as an example case study. While a home-use cogeneration system is expected to efficiently provide electricity and head simultaneously, their demand levels depend on the family structure, which is systematically variable. On the other hand, since a system is composed of a generator, a heat accumulator, a boiler, etc., it can be reconfigurable by partially replacing its subsystems. In the paper, a representative situation of socially exchangeable artifacts is illustrated under several scenarios, and then some prerequisites are discussed toward their environmental optimality.

View full abstract

Japanese government has enhanced various kinds of environmental policies towards the low-carbon society. The objective of this study is to design environmental taxation system in order to promote environmentally friendly products. This paper proposes an environmental taxation scheme for clean energy vehicle's (CEV) by using LCCO2 emissions through three phases; material production phase, manufacturing phase, and running phase. The idea comes from the estimation that the rate of manufacturing phase in LCCO2 increases as the CEV's penetration grows. The simulation results shows that the CEVs has less life cycle costs than conventional gasoline cars with a certain rate of the environmental tax which will help consumers to choose CEVs. Some problems such as reduction of the total tax are discussed as well.

View full abstract

Sustainable development (SD) has become a critical issue due to growing concern about environmental problems in recent years and firms are obliged to justify their presence in society more than ever before. In this context, business planning, monitoring, evaluation, and communication with customers and wide variety of stakeholders from sustainability perspective are indispensable as well as those from economic perspective. Although growing number of tools for SD have been proposed, it is often difficult to clarify which business activities actually contribute to (or violate) SD due to high complexity of environmental and economical system of our society. In order to handle this complexity in a systematical manner, this paper proposes a method for collecting and describing various cause-effect chains from existing business cases, identifies patterns among them based on causal-loop diagram, and formulate them into a pattern library so that businesses can easily identify hot-spots in their activities by relating them with cause-effect patterns provided by a pattern library.

View full abstract

In order to achieve the efficient design process, various infrastructures and tools have been developed and provided with the advanced IT technology. Any of them, however, cannot effectively support managers making appropriate decisions for process design. In order to achieve the effective support, a method to quantitatively predict the designed process should be developed. Our simulation based approach (PMT: Process Management Too) can quantitatively analyze and predict the designed process performance with various performance measures, considering the process element and their characteristics, their behaviors and their influencing factors, and the structure formed by the elements and their static relationships. In this paper, PMT was applied to examine the process performance of the product based process and the functions based process regarding a forming dies design process as an example of actual application. In the examination, work processing capability and communication processing capability were focused. Through the examination of work processing capability, PMT analysis revealed the fragility of product based process and the tolerance of function based process to overload respectively. It also indicated how to allocate human resources to maximize the work processing capability. Furthermore, it precisely indicated where to allocate the specific types of labors in the function based process though the examination of communication processing capability.

View full abstract

This paper proposes a methodology to evaluate organizational performance using a developed engine. The engine seeks the minimum time required to accomplish the production process based on the various tasks defined, composition of workers, and the individual worker's skills. By quantitatively evaluating the influence of different organizational structures, this paper will show that the developed engine is helpful in making the optimal production process.

View full abstract

In order to enhance competitiveness of a product, it is indispensable for a manufacturer to tackle a new design based on any technical innovation such that quality and performance of a product is improved. However, a new design involves many risks such as the delivery date delays and the quality losses because of less experience. This research proposes a new method of design process planning that supports management of milestone and multiple back up options, and risk hedge of a new design in consideration of substituting an established design for a new design as a back up. The prediction of risk is carried out by a design attainment prediction model proposed. A prototype system that supports design process planning based on the proposed method is developed. This paper demonstrates its application to a student formula car project.

View full abstract

In product development, a product plan is considered before conceptual design. The decision-making in the planning phase is performed by collaborative work of marketing, financing, and technology divisions. Decisions in the product planning phase are used as constrains of the following conceptual design. As a result, the product planning plays a highly important role to determine the direction of product development. In this study, we investigate actual product planning processes and consider how to improve the reliability of product planes. We will show a framework for visualizing the justification and risks for decision-making in the product planning phase.

View full abstract

Industrial designers are new-creating both function and attribute of product in the conceptual design process. Quality of product depends heavily on their creative thinking. Therefore, it is difficult that computer-aided system supports a creative and inventive thinking process. We proposed the methodology of Conceptual and inventive Design Support System (CDSS) for its difficulty and estimated this methodology to satisfy the requirement. In this paper, we propose new analysis model by using contact and observer objects into use case diagram for CDSS, and estimate this model by questionnaire and rough sets. Furthermore, we experimented by adopting psychology about the estimation of the guidance method of using observer object. The validity is discussed thought the result of them.

View full abstract

As a business environment changes faster, companies intend to form a supply chain to complement resources each other that are valuable when distributed unevenly. In such a situation, a supply chain manager has to divide supply chain activities to match its demand and supply and assign them to supply chain organizations properly in order to utilize resources of each organization fully. However, causal relationships of supply chain activities and performances are quite complex and ambiguous and it is not easy to establish an ante-rational plan for supply chain improvement. In this research, by viewing a supply chain as a composition of structures and operations with a hierarchical organization structure, decisions and a decision making process of supply chain management are simplified and generalized. Then, relationships between organizational capabilities of supply chain structures and operations and its performance are organized by applying quality function deployment methodology. Finally, these relationships are modeled on system dynamics, which enables quantitative simulations of supply chain performance with its parameter that represent structural and operational capabilities.

View full abstract

Recently, global competition and serious economic forces product companies to develop more competitive and more complex product in a brief time. For the fact, carrying out the project for product development becomes difficult. There are some challenges for the problem, but most of them are based on the assumption which As-Is model are described already. This paper tries to assist the project management through the description of the As-Is project model.

View full abstract

To enhance designers' creativity during collaborative design processes, this research focuses on designers' individual differences, especially the differences in their evaluations, and develops a new method for analyzing their differences. In the proposed method, designers first individually evaluate ideas from the viewpoints of numerical performance and semantic interpretation. The system then analyzes designers' evaluations and reveals the details of their differences. For example, which ideas cause great differences in designers' evaluations? or which pairs of designers have greatly different viewpoints or recognitions in their idea evaluation? By utilizing revealed individual differences, designers can explore new ideas more effectively and efficiency.

View full abstract

It is a purpose in this research to develop the examination model of the elevator that becomes independent and can go up and down by relations to the maintenance through the research of the stratospheric platform for the high-altitude observation is researched by various laboratories now. It is the one to examine the characteristic of the going up and down experiment machine by taking various data centering on the vibration, and for the best shape and the structure to grope there. This time, the speed test and the vibration test were done by the tether of the high degree 150m participating in the space elevator engineering competition. The data collection in a situation near the reality or more of the twist of the tether by the wind etc. that were not able to be reproduced indoors was done.

View full abstract

Life cycle design requires planning of a product life cycle in addition to designing of a product itself. One of the effective methods to plan the product life cycle is by describing of a life cycle scenario, which should be then realized by designing the product and its processes. On the other hand, the life cycle scenario should be decided by keeping the consistency of the product's functionality and performance. This paper proposes an integrated design environment to support the life cycle design comprehensively. In other words, we propose a design system that supports a designer to describe the life cycle scenario and to design product in an integrated manner.

View full abstract

Minimizing environmental loads and costs throughout a product's lifecycle requires appropriate lifecycle design in addition to the design of the product itself. Design of a lifecycle of a product involves planning lifecycle strategies, evaluating it from various viewpoints and optimizing the overall picture based on the item's properties. A product's lifecycle strategy can be designed easily by describing lifecycle scenarios at an early stage and the product architecture should match the desired one. In evaluating product structure, we must take into account the applicability of scenarios to the designed product. We should derive plausible product structure implementing an executable lifecycle scenario under the equilibrium between its process costs and reduction effects on the environmental loads by executing the scenario. In order to include this aspect, we formalize the probability that each component will follow the preferable lifecycle paths designated by the scenario. We also propose an index for evaluating and improving efficiency in resource circulation of the designed product structure.

View full abstract

Life cycle design is indispensable for minimizing the environmental loads and costs through the whole product life cycle. In life cycle design, modular design is an important elemental technique to improve, e.g., maintainability, upgradability, reusability, and recyclability. It unifies components that go through the same path in the lifecycle flow and increases the efficiency in resource circulation. For representing this advantage, we introduce resource efficiency as an evaluative index for product modularity by employing the concept of eco-efficiency. For the evaluation, we formalize the probability that each module goes through preferable lifecycle paths designated by its lifecycle scenario. This paper also illustrates the prototype system that implements the proposed method and a case study of an ink-jet printer

View full abstract

Increasing productivity and efficiency of resources is a major approach within the framework of sustainability in manufacturing. This paper proposes a design method to simplify the structure of a product as a key technique for increasing resource productivity. Our method removes redundant components and their connections by extracting a minimum structure as an ideal minimized formation of connectivity. Designers then redesign the product by embodying the minimum structure to meet design requirements. The method was implemented to verify the advantages of the methodology and presents several potential redesigned geometric models. This paper also illustrates a case study using models of a vacuum cleaner and an inkjet printer in order to discuss effectiveness of the proposed method.

View full abstract

It is necessary to achieve an effective product lifecycle management to shift from a society with mass production and mass consumption that brings environmental problems and an exhaustion of resources, to a sustainable recycling society. A difficulty for manufacturers to realize a reuse-based production is that they cannot predict how many reusable parts with what quality are taken back from consumers. To solve this problem, a system supporting the collection of deterioration information of products in use at consumers is proposed using network agents in order to facilitate the communication between manufacturers and consumers, which enables the manufacturers to create an effective manufacturing plan of products.

View full abstract