In this paper, investigation on vibration characteristics of the human middle ear was carried out using the finite element harmonic vibration analysis. It was clarified that there is a relationship between hearing ability and stapes displacement including frequency characteristics. In tympanoplasty, the linkage of auditory ossicles may be reconstructed using the column article called the columella. It was also confirmed that stapes displacement changes according to the shape of columella or its mounting position to malleus. Then, a new method is proposed for estimating the hearing restoration effect prior to the tympanoplasty operation. That is, the hearing restoration effect can be estimated by a comparison of the differences in the stapes displacement between the reconstruction model and a healthy subject. In this study, as a part of the optimum design of the columella with the aim of better sound conduction efficiency, the correlation of columella junction area to the auditory ossicles and hearing restoration effect was clarified.

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There are many senses of beauty such as functional beauty, structural beauty and so on. Most likely, they have some reasons and if we understand underground reason, we can divert to other engineering problems. And ideas come from it may be great fruits in some sense. For Topological beauty, in the most case, determined by force conditions and support conditions. And with topology optimization tool such like OPTISHAPE, we can have topology shape through it. In this study, we have started from simple case, and with knowledge from it, we have developed it to some complex cases.

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Mathematical programming is one of the means for obtaining a solution of a certain objective function, and there are a gradient method and a Newton method. The steepest descent method is said to be the most fundamental method, and is a method of lowering the objective function along the inclination direction of the objective function. As an application method of this steepest descent method, there is what is called an acceleration gradient method. In the steepest descent method, a solution is obtained when ∇f = 0, but as the solution approaches, the amount of change decreases and it takes time to reach the solution. However, in the acceleration method, even when approaching the solution It has the advantage that quantity does not decrease greatly. From this, it can be expected that the time of analysis and the number of calculations are greatly shortened. The Newton's method is a method of performing analysis using the second derivative of the objective function. There is what is called a quasi-Newton method as an application of Newton's method. The quasi-Newton method is a method that can be expected to obtain a solution only with the information of the first differentiation. This makes it possible to obtain a solution even if it is difficult to obtain the second order differential. In this research, we propose a method combining these two mathematical programming methods. In addition, by using PSO as parameter adjustment, we find the best parameter, aiming at optimal solution while comparatively reducing the number of calculations.

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The aim of this research is to construct a topology optimization method for flow fields in redox flow batteries (RFBs), which have attracted attention as next-generation storage systems for renewable energy resources such as solar and wind power. It is widely known that one of the key factors in boosting charging/discharging efficiency of RFBs is the design of the flow field. To achieve high-performance RFB, in this study, topology optimization is applied to obtain the optimized flow field that is composed of flow channels and porous electrodes. The optimization problem is formulated as a maximization problem of electrochemical reaction rate that corresponds to the charging/discharging efficiency. The porous electrode is governed by Darcy’s law in which the permeability is defined using a typical porous model. As a first step toward developing a basic methodology for RFB designs, a simple two-dimensional model is proposed; furthermore, a linearized electrochemical reaction model is introduced. A numerical example is provided to confirm the efficacy of the proposed method.

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Rarefied gas flows have a property of that they are induced by thermal gradient without any external forces. We made a fundamental study for the introduction of topology optimization to the design of a thermal fluid metamaterial which utilizes such a unique property of rarefied gas flows. In particular, in this study we constructed a numerical method to solve the coupling problem between rarefied gas flows and heat conduction in solids for the structure implicitly represented in the calculation process of the topology optimization. At first, we adapt the level-set method for the implicit expression of the structure and extend the governing equations, namely the Boltzmann equation for rarefied gas flows and heat conduction equation for solids, to the whole domain consisted of gas and solid so that the coupling boundary conditions are automatically imposed at the solid-fluid interfaces, based on the shape expression. Then, we construct the numerical implementation method for analyzing the coupling problem according to this extended formulation. Finally, we confirm the validity of the proposed method through a numerical example.

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Thermal design with nanoscale is essential when developing miniaturized electronic devices. The implementation of nanostructural designs utilizes unique properties of heat conduction such as temperature jumps on material interfaces. It lets us obtain a novel high-performance electronic devices. However, few reports proposed thermal-designs have been dependent on heuristic approaches. There is a large demand for constructing the design methods of nanoscale thermal problems. In this paper, we propose a structural optimization method utilizing the Level-set method for a two-phase thermal design problem considering temperature discontinuities. The Level-set method let us obtain the optimal structures with clear boundaries and consider the boundary effects during the optimization procedures. It is a useful tool for a nanoscale thermal design, since the boundary effects are essential for developing a novel material properties. First, we clarify the design problem of a nanoscale heat conduction based on the Boltzmann transport equation. Next, we construct a method for a shape sensitivity analysis for a heat conduction problem considering two-phase nanoscale effects by expanding the work of Pantz. Then, we apply the structural optimization based on the Level-set method to our problem. For a first step of constructing a nanoscale design method, the validity of our shape sensitivity analysis is demonstrated through a numerical example.

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This paper reports the structural optimization, using a topology optimization method, of an electromagnetic wave shielding device made of thin metallic film, whose frequency of operation can be chosen. Currently, with ongoing improvements in electromagnetic wave transmission/reception technologies and the spread of the Internet of Things (IoT), electromagnetic interference (EMI) has become a serious problem. To solve this kind of problem, devices that provide shielding against electromagnetic waves of only specific frequencies have been designed and examined, by arranging periodic arrays of thin metallic films. An effective design method is needed, since the performance of such devices greatly depends on their shape and size, but at the moment, trial and error methods based on engineers’ skills are used and enormous development time and expense is required to obtain structures that provide superior performance. To solve this design problem at a fundamental level, we propose a topology optimization method, although there are as yet only a few examples that use topology optimization to design thin metallic films for operation in electromagnetic fields. One reason for this lack is that when a metal is used in a high-frequency electromagnetic field, this leads to the so-called skin effect, a phenomenon whereby the electromagnetic waves permeate only a few nanometers along the surface of the metal. In a conventional topology optimization method, after discretization of the metal portion, the calculation load becomes too large to complete if the elements are divided finely enough to take the skin effect into account. Conversely, if a coarser discretization is used, the real phenomenon will not be expressed accurately. Therefore, introducing a boundary condition that can effectively handle the skin effect in a topology optimization based on the density method, the design of a frequency selective electromagnetic shielding device for use in a high-frequency electromagnetic field, such as 9 GHz, can be optimized.

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Fabrication cost of trusses usually increases as the number of nodes increases. To reflect this cost in the early design phase, this paper presents the compliance minimization of trusses under the upper bound constraint on the number of nodes. It is shown that this problem can be formulated as convex optimization with a ℓ₀-norm constraint (also referred as a cardinality constraint). We propose a simple heuristic approach to this optimization problem based on the alternating direction method of multipliers (ADMM). Computation of each step of this algorithm can be carried out efficiently and implemented easily. It is demonstrated through numerical experiments that the proposed method can often find a solution having a good objective value with small computational cost.

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In this study, we propose a new approach to control the transient response of a shell structure by optimizing the thickness. The free-form optimization method for shells, a parameter-free shape optimization method developed by one of the authors, is extended for the transient response problem of a shell structure. The design objective is to minimize the dynamic compliance or to control the displacement at arbitrary domains and time to the desired values under volume constraint. This problem is directly solved without converting the discrete equivalent static loads, which is often employed in time-dependent optimization problems. The optimum design problem is formulated as a distributed-parameter optimization problem and the sensitivity function for this problem is theoretically derived based on the variational method. With the H 1 gradient method for scalar design variable, we determine the optimum thickness distribution of a shell structure while minimizing the objective functional and maintaining the smoothness of the thickness distribution. Some optimum design examples are demonstrated and the results are discussed.

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In this paper, we present a simultaneous optimization method for designing the shape and topology of a laminated shell structure. Multi-objective compliance of a laminated shell structure is minimized under volume constraints of shape and topology optimization, and the out-of-plane shape variation and the fictitious density are used as the design variables. The SIMP (Solid Isotropic Material with Penalization) method is used in topology optimization. The optimal design problem is formulated as a distributed-parameter optimization problem, and the sensitivity functions for density and shape variation are theoretically derived. Both the optimal density distribution of the design layers and the optimal shape variation are simultaneously determined by the H¹ gradient methods for vector and scalar design variables, where the sensitivity functions are applied as the Robin condition to the design mid-surface and the design layers. The verification and validity of the proposed method are demonstrated through design examples.

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Advancement of computer technologies as well as the developments of structural materials and construction methods have enabled us to design a so called free-form shell, which has complex shape and topology that cannot be categorized to traditional shapes. However, the mechanical behavior of such a shell is very complicated, and it is very diffcult for a designer to decide feasible shape of a real-world structure based on his/her experience. Based on such back ground, in recent years, some shape optimization methods for continuum shell structures, which have a strong relationship between shape and structural rationality, have been proposed actively. On the other hand, thickness distribution is also an important aspect of shell structures. There exist not so many studies on the optimization methods which treat shell shape and plate thickness simultaneously. From the view point of structural feasibility, constructability and topological clarity, it is not acceptable that the plate thickness takes an extremely small value. Therefore, the part with a thin plate thickness should be an opening, which requires to use a topology optimization approach. In this paper, a simultaneous optimization method of shape, thickness, and topology of shell structures is proposed. Efficiency of the proposed approach is investigated through several numerical examples, and the characteristics of the results are discussed.

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We proposed an advanced mesh generation technique that reuses the proven analysis models by similar sub-part search. The purpose of this development is to reduce interactive mesh improvement work time and to comply with the mesh specifications. It is our feature technique to search sub-parts similar to the archived sub-parts of proven models from new design CAD. In this technique, the similar sub-parts are retrieved from a CAD model described by boundary representation and made correspondence relation surface pairs of a retrieval model (proven model) and a target model (CAD of new design). A similarity score is based on the attributed graphs of a retrieval model and a target model. And, this score is calculated by a geometrical similarity and topological similarity. If there is such search noise, unreusing sub-parts must be canceled by interactive operation. This is an obstacle to automation. Therefore, with the goal of eliminating search noise, we developed a technique to improve the accuracy of similar partial shape retrieval. By quantifying the geometric relationships such as concentric circles and face-to-face distance as similarity, high precision could be realized. It was applied to a door switch cover part of an automobile which is a verification model, and it was confirmed that search noises disappeared.

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In this paper we introduce an algorithm for generating collision-free two-lane haul road for unmanned vehicles used in the mining areas in terms of quartic B-spline curves. Given the boundary geometry of the haul road area, positions and 2D vehicle orientation at the start and goal points, the algorithm automatically generates collision-free haul roads that possess slope continuity of curvature at knots. Examples are provided to demonstrate the effectiveness of the proposed algorithms.

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Industrial X-ray CT scanning systems (XCT) have been used for obtaining 3D shapes of mechanical parts. In this study we are interested in scanning a whole assembly made of several parts made of different materials. It has several advantages such as reducing scanning labor compared to that needed for scanning each of the parts by skipping disassembly process and also by reducing scanning operations. However, such whole assembly scanning is not a common practice as it is difficult to extract the parts from the volumetric image of the whole assembly. This process is generally called segmentation. Currently, an operator needs to spend long time on manually segmenting the volumetric image. This paper proposes a new segmentation program SegMo. It is based on a cell decomposition of the volumetric image with Morse complex defined with a function of the norm of gradient of the CT values of the image. The Morse complex has cell boundaries including parts’ boundaries. By constructing LOD (level of details) hierarchy of the Morse complex, a user can select an appropriate level of the hierarchy where the boundary of the target part is well reproduced and thus can form a region of a part. A system based on the SegMo with GUI (graphical user interface) is developed on ZVoxer system of Zodiac corporation. It has been applied to various examples to show that the SegMo system can perform segmentation more quickly and with less effort than conventional methods. In this paper, we describe the algorithm of the SegMo and its experimental results.

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In the past, National Maritime Research Institute developed the system for curved shell plate forming which is usually regarded as a special skilled work in a shipyard. The system mainly improves sheet metal forming work efficiently in shipyards, and also for improving an accuracy of a curved shell plate developing in a design stage. However, this system still has room for an improvement in regards to surface representation of ship plates. In this paper, an iterative geometric approximation method, which iteratively repositions B-spline control points on the basis of geometrical rules, is introduced to fit points data of ship plate for the purpose of improving accuracy of the system. Finally, this paper provides results of surface approximation of ship plate and its demonstration of the plate forming in a shipyard using our new system.

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Focusing on the pupil response which is related to human emotions, we analyzed the pupil response in human face-toface communication and demonstrated that the pupil response would be related to the speech. On the basis of the analysis, we developed an embodied communication system in which an interactive CG character generates the pupil response by using speech input for realizing smooth communication during embodied interactions. In addition, it was confirmed that the pupil response is effective to enhance emotional expression. In this study, in order to extract the effect of pupil response, we developed an expressible pupil response interface using hemispherical displays. This interface looks like robot’s eyeballs and expresses vivid pupil response by using speech input. In addition, we carried out the communication experiment under the condition that the developed interface speaks. The effectiveness of the developed interface was demonstrated by means of sensory evaluation.

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In remote communication, a motion display that operates a display like a movement of a human head is one way to improve presence. The movement of the head of a human is calculated by OpenFace which is a face behavior analysis tool by image processing, and a system which controls expression of the head motion using the robot arm was constructed. However, in telecommunications, communication partners and robots are not in the same place as in a stand-alone configuration. Therefore, networking using remote communication technology is required. The system was networked by dividing the standalone configuration into three parts, the input part, the processing part, and the output part, and connecting them by a network. In networking, using the video streaming software using the HTTP protocol for input to the processing unit, the transmission of the orientation information of the head to the output unit for controlling the robot arm is carried out by message transmission software using the MQTT protocol. The robot was operated using the created system, and the robot's motion and human motion were simultaneously measured, and the difference in operation between the stand-alone configuration and the network configuration was measured. And the evaluation of the human reaction when presenting the motion of the robot by this system was done. Human response to robot motion was evaluated by measurement of subject's gaze. In the standalone configuration and network configuration using HTTP and MQTT, the gazing point follows the motion of the robot.

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Sports vision is a collective term for visual information processing ability in sports. Sports vision plays an important role in the ball games, because the bargaining with the opponent players is important on the basis of visual information. In order to advance dominantly in the ball game, the comprehensive ability that can recognize the opponent player in the peripheral vision and perform to generate motion based on that information is necessary. In this paper, we develop a peripheral vision training system integrating sports vision and motor system. In this system, the tennis with a clear distinction between the ball and the opponent player is targeted, and the user controls the striking direction according to the movement of the opponent player. In addition, the developed system can evaluate the reaction objectively by measuring this striking direction and timing based on the sports vision using the measurement device.

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Shadows are usually natural and unintentional in real space. In virtual space, they play an important role in threedimensional effects and the perceived reality of the virtual space. An avatar’s shadow can have interactive effects with the avatar itself in the virtual space. In this study, we develop an embodied avatar system using avatar-shadow color expressions with an interaction-activated communication model. This model is based on the heat conduction equation in heat-transfer engineering, and has been developed to enhance empathy during embodied interaction in avatar-mediated communication. A communication experiment is performed with 12 pairs of participants to confirm the effectiveness of the system. The results of the sensory evaluation show that interaction activation is visualized by changing avatar-shadow color.

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In this research, we focus on 3D pen. The 3D pen is a tool that can output a melted resin from a pen tip to form a 3D object. In order to shape an object using the 3D pen, it is necessary to practice it and understand how to use the tool, and many beginners find it difficult to handle. Most of the difficulty is caused by users not understanding the appropriate moving speed. On the other hand, it is necessary to have interactivity in the learning something. In 3D object drawing learning, a learning system using VR/AR capable of displaying three dimensions is desired. In this research, we aim to support learning in 3D object drawing, and proposed and developed the 3D object drawing learning support system with interactivity. Furthermore, the influence of the proposed system and a video learning system on 3D object drawing skill by 3D pen is examined. As the results of the experiments, it was necessary to practice 3D drawing with 3D pen, and it was demonstrated that interactive learning may be more effective than non-interactive learning after practicing 3D pen. In addition, it was suggested that interactive learning is more likely to make feel that learners improved with respect to speed and drawing related to pen. And also, it was suggested that those who are not good at 3D drawing are more likely to feel that interactive learning has improved their drawing techniques.

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In this paper, the use of motorcycle HUD is proposed and evaluated through testing by operating a HUD prototype in a controlled real world environment using actual vehicles. The proposal of motorcycle HUD has been evaluated through human-centered design using virtual environments, realizing to develop a real world operational HUD for motorcycle navigation. However, evaluations in virtual environments are well controlled and simulated, therefore, the rider’s riding behavior may be different from actual riding situations. Testing prototypes in real traffic situations can still be dangerous regarding irregular situations that may occur. Hence, testing in a controlled environment is necessary for prototype evaluation using actual vehicles. We used private roads inside the university campus as a riding environment to conduct experiments. A riding course has been set by combining one-way roads and parking spaces, making a simple loop course so the subject can come back with simple navigation. From the experiment, we observed how the designed motorcycle HUD was capable in presenting information in the real world riding environment.

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Manufactures in developed countries have made efforts on sustainable global production such as the development of eco-products for developing countries. However, industrial products designed in developed countries are not always acceptable for developing countries. One of the reasons is differences in culture, social contexts and lifestyles between them. It is important to understand such local information and to reflect it in product design. The authors has proposed “locally-oriented design” as a design methodology focusing on local specific needs and constraints. In order to support the process of the locally-oriented product design, this paper proposes a virtualized reality environment in which a designer evaluates the design from a holistic viewpoint including the local information of the area. This quasi-realistic environment composed of omni-directional images captured from multiple viewpoints in a real world where the target product is installed and used. The designer can move and look around freely in the immersive environment through a head-mounted display, and evaluate the design of products based on operational burden of users. The effectiveness of the system is demonstrated on a washing machine installed in a house of Vietnam in a case study.

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Quantitative relationship between Kansei and physical quantity is necessary to design Kansei quality. In general, such relationship is obtained from sensory evaluation with participants. Number of samples that participants can evaluate is limited. Thus, efficient experimental design under limited number of samples is required. In this study, we consider prior estimation of experimenters and past experimental data. We adapted QFD matrix to obtain experimenter’s prior estimation or intuition and combined design parameter using the matrix. We adapted kernel density estimation to recommend effective experimental parameter. In this method, we aimed to recommend the experimental points from the part that is not in the vicinity of the region where existing experimental points exist, from the part with high sensitivity. We used hierarchical Bayesian model to model individual variation of regression coefficients.

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Words are communication media to share a concept in a community (e.g. an industrial company and research group). A word involving ambiguity represents multiple concepts (or meanings) depending on a context. Such ambiguity causes misunderstanding between people having different contexts. On the other hands, a community uses words to obtain responses and/or evaluations from target population, such as customers and participants. The word ambiguity causes misunderstanding between a community and a target population due to different contexts. A community dealing with multiple languages (e.g. multinationals) has a difficulty in translation if there are no words in a second language, all meanings of which do not correspond to all meanings of a word one wishes to translate. To deal with above issues caused by word ambiguity, we propose a multilingual semantic networks(MLSN) framework in this paper. The MLSN is a graph where multiple languages words, as nodes, are semantically linked through concepts, as another type nodes. We implemented MLSN in a graph database with datasets of WordNet in three languages: English, Japanese, and French. With MLSN, we conducted two analysis. In the first analysis, we investigate the meanings of ambiguous words such as “design” and Japanese word “Kansei”, and their semantic relations with relevant words in other languages. We found that there are no words corresponding to all meanings of those words in second languages. For the word “Kansei”, we illustrate semantic relations with words such as “emotion”, “affect”, “feeling”, “impression”, and “intuition” which are often used to define “Kansei”. In the second analysis, we discuss how MLSN supports to select and translate a set of words used as evaluation descriptors. We analyze 10 positive emotion words from well-established Geneva Emotion Wheel and their translation in French and Japanese. We demonstrate how MLSN automatically find translation mismatches and semantic independence between emotion descriptors. Based on discussion through abovementioned analysis, we propose a multilingual word suggestion system that can be used for both disambiguation and translation support.

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The aim of this study was to investigate the effect of touch screen installation position and button size on body posture and workload. Ten students (five males and five females) participated in this study. The subjects utilized a touch screen with different installation height (50, 65, and 80% of stature), tilt angle (0°, 45°, and 90° from the horizontal plane), and button size (a square with a side of 10, 20, and 30 mm). The joint angles during the tasks were measured to calculate the joint moment ratios (JMRs) of seven joints: the neck, shoulder, elbow, wrist, lumber, hip, and knee. The subjective scores of ease of operation and visibility were also measured. The results showed that JMRs of trunk and lower limb were higher than that of upper limb. The smaller button size worsened the JMR and the subjective evaluations. The smaller tilt angle improved the maximum JMR and the subjective evaluations in the range of the lower installation height, whereas the larger tilt angle was preferable in the higher installation height. The optimal installation height and tilt angle for the workload reduction were in 68–74 % and 45°–60° ranges, respectively. It is preferable to decrease the tilt angle for the button size of 10 mm by 6 ~ 8° compared with the size of 30 mm.

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Making new ides is the centerpiece conceptual design activity. In this activity, to explore one big product, product over 3000 ideas are required (Stevens and Burley, 1997). Moreover, Successful companies provide the highest quality service, by which customers receive satisfaction through a Kando experience. Thus, customer satisfaction through their experience is necessary for greater success in business. In this paper, we newly focus on recommendation that "Telling stories that appeal to the hearts of people to connect an idea to a single emotion" is effective for making people heart move. So we report the method of idea creation support system(ICSS) introducing the catch phrase creation process.

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The visualization of Kansei value as requirements and the realization of its value for making a product idea in a conceptual design are desired. Therefore, Sato have proposed the Idea Creation Support System (ICSS) - for an idea creation with Kando understanding process through WOM (Word Of Mouth) effectiveness. However, ICSS could not realize a visualization of a requirement according to topology, i.e., shape and layout, through understanding Kansei value clearly. For realization of this problem, we propose the shape creation method which consisted of Analysis Fully Stressed Design as a shape creation system and the Kansei information understanding of a topology through Electroencephalogram (EEG).

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The design process is highly dependent on individual sensibilities in general. There is, however, also implicit objective factor in this process, such as physical rationality. In order to support the design, revealing the connection between the sensory- and the objective-factors is a key. We focused on the process providing the impression of the product shape and proposed a concept of “expression in mechanics sense” by means of the spatial pattern of stress level that might be implicitly perceived by humans. The term of “expression” is a metaphor of human facial expression. In this article, we described a methodology for explaining how humans recognize the shape of the product through the deep learning approach and for associating with spatial pattern of mechanical stress.

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In recent years, the importance of Product-Service Systems (PSS) which forces on generating higher value by integrating physical products and services has been recognized widely in the field of manufacturing. In order to enhance the value of PSS, value co-creation is very important. To realize value co-creation, a provider and a receiver apply appropriate their knowledge and skills. Herewith, they create value-in-context in value co-creation. However, value-in-context is defined by the context, which is provided by actors’recognition. Therefore, each actor has different context in the same service. Hence, it is difficult for a provider and a receiver to co-create value-in-context effectively. However, a method for supporting the sharing of contexts has not yet been established. In this paper, the authors propose context modeling method for extracting and expressing receiver’s context.

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Developing a reliable forecasting method enables to optimize the overall planning of production for remanufacturer. Owing to the uncertainties in timing of product returns and demands, remanufacturers perceive difficulties in forecasting and are still exploring superior forecasting methods. Prior research proposed two forecasting methods for remanufacturing, based on the Holt-winters model and the Weibull distribution model. In this study, a pattern based demand forecasting method was proposed. In this method, the defects of the Weibull distribution model were analyzed and modified by applying constraints and categorization rules. To verify the effectiveness, actual time series data of sales for remanufactured alternators of an independent remanufacturer were used. The results provided average errors between actual value and forecasted value were 35.3% for the Holt-winters model, 41.7% for the Weibull distribution, and 24.9% for the proposed model.

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This paper proposes an index for evaluating product module’s adaptabilities of lifecycle options. The purpose of this index is to provide designer a guideline for designing multi-generational product that belongs Upgradable Product Service System: Up-PSS. Usually, developing upgradable product needs to predict future market trend, procurement cost and so on in the early design phase. Therefore, a designer has to consider many uncertain design information. This study defines such information which is used for evaluation perspectives in proposal index as ranged value. In addition, proposal index evaluates module’s upgradability, remanufacturability, and reusability by using ranged parameter and concept of set-based design for adapting such uncertainty. Previously proposed indexes evaluate component’s lifecycle options without a consideration of economic and environmental perspectives and requires complicated calculation algorithm. These characteristics are burdens on a designer who is required not only to design product but also to analyze product features. For these conditions surrounding a designer, proposal index comprehensively evaluates component-adaptability of lifecycle options by four evaluation perspectives: functional (priority of a module), economic (production cost), environmental (CO2 emission at the production phase), and reliability (durable life) perspectives. Furthermore, this index requires only simple computation rule and prevailing spreadsheet software. The authors evaluate laptop’s moduleadaptabilities of aforementioned three lifecycle options by proposal index as a case study. From the result of this evaluation, proposal index is able to provide a guideline which is the decision-making of providing function and selection of platform components etc. for developing upgradable product service.

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Recently, new business strategy called “servitization” has been attracting much attention in manufacturing companies. Servitization means the shift from production and sales of product to providing services with product, and has a potential to improve competitiveness and sustainability and reduce environmental impacts in manufacturing companies. Actually, successful cases of servitization have been reported in European countries. Therefore, many researchers have advanced research for supporting manufacturing company to realize servitization. Previous studies have pointed out that servitization in manufacturing companies moves to step by step. However, these studies couldn’t present detail requirements in order to move to the next phase. This paper researches the requirements for providing required service and barriers which prevent satisfying the requirements in servitization phases. In particular, we will organize the each stage of servitization by investigating literature review and perform questionnaires survey to various companies. Finally, based on the result of them, we will clarify the requirements and barriers in servitization phases.

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Although remanufacturing is an important life cycle option for increasing resource efficiency and realizing circular economy, it cannot achieve enough market share in many developing countries. In order to analyze this problem, we proposed a market competition model by employing polynomial logit model and incorporated it in Life Cycle Simulation. As a case study, we simulated competition among new, remanufactured, and refurbished products in Thai photocopier market. The simulation results indicated two messages. First, the remanufactured products might be diffused if we secured enough number of cores (i.e., end-of-life new products), including importing them from developed countries, and promoted advantages of the remanufactured products. Second, since the polynomial logit model relates attributes of products and their life cycles with the probability for choosing a product, the proposed model is useful for evaluating policies, life cycle design, and product design for their effects on the diffusion of the remanufactured products.

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Envisioning sustainable energy futures is a pressing issue to reduce CO2 emissions, ensure energy security, and maintain quality of life (QoL). This paper aims to describe energy visions on municipal scale by taking a backcasting approach. To brainstorm various ideas and views in a local context, we hold participatory workshops involving citizens, municipal government, and researchers. Additionally, we attempt to create imaginary future generations as participants in the workshops in order to reflect the needs of future generations in energy visions. A case study of Suita City is carried out in which backcasting scenarios are developed to describe sustainable energy visions both on demand and supply sides in 2050, followed by drawing potential policy options to achieve the visions.

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Because of the diversification of customer needs, value creation process with goods-dominant logic (i.e., supply chain) is limited to fulfil customer satisfaction. The purpose of this paper is to elaborate the mutual value exchange between company and customer under the service-dominant logic (i.e., value co-creation). Using the concept of value constellation and a method of goal-oriented requirements engineering called i∗ (i star), value co-creation process is refined by modelling value proposition and integration of resources by each company and customer.

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In the service design and provision, the value-in-context is co-created under the influence of the stakeholder context. In order to enhance the value, it is necessary to clarify and share the context, then we can realize value co-creation utilizing the result. However, in current manufacturing industry, universal value proposition is being made by providers due to the establishment of manufacturing methods that emphasize efficiency improvement and cost reduction by mass production in recent years. As a result, products and services that do not match their respective values have been provided. This makes it impossible for stakeholders to take appropriate actions (application of skills, knowledge, etc.) at the phase of using / consuming their products / services. Therefore, this study aims to establish a method to support the service design that can continue to perceive value over the long term by taking appropriate action by each stakeholder involved in the service. In order to achieve this purpose, this paper proposes a context modelling method to understand and share information on each stakeholder (request, know-how, knowledge on technology, design intention, etc.) necessary for service design.

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In manufacturing field, the concept of Product Service Systems (PSS) has begun to attract attention as create value of manufacturers’ products and build up strong relationships with their customers. Comparing traditional business model, the PSS designers need to consider more the value of all stakeholder in which involved. Moreover, they are also required to analyze all cost related to product and service in all life cycle phases of their PSS. In PSS design research field, some researches have proposed a method to design PSS based on perspective of life cycle cost (LCC). However, they analyzed LCC only from the perspective of producer or customer and in order to design PSS, it is necessary to consider the values of multiple stakeholders involved in PSS simultaneously because of above mentioned reasons. From this background, this study aims to establish a method to design PSS considering value of multiple stakeholders. Specifically, this paper proposes method to structure needs of multiple stakeholders, functions and entities that realize their needs. Further, the authors analyze the dependency relationship between these PSS building blocks, and associates them with each life cycle phase of target PSS using a life cycle cost model.

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In order to investigate how low-carbon products, such as photovoltaic (PV) panels will reduce regional CO₂ emissions over a longer period of time (e.g., 30 years), we describe scenarios to analyze the relationship among various social changes in the future (e.g., energy policy), the amount of low-carbon products diffused in a region, and the resulting CO₂ emissions throughout the life cycle of the products. In this paper, we develop an integrated model for estimating the diffusion of low-carbon products and the CO₂ emissions due to the diffusion of low-carbon products using life cycle simulation. In a case study, we described several PV diffusion scenarios toward 2045 for the Tokyo area, in which we evaluated PV installation capacity and the CO₂ emissions caused by PV diffusion. The results showed that the ownership rate of PV in 2045 would account for 36.8-53.6 %. In addition, it was revealed that the extension of product lifetime provides the potential opportunity to reuse secondhand PV, causing less CO₂ emissions than other scenarios.

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When designing a structure of a rotor of interior permanent magnet synchronous motor (IPMSM), optimization for layouts of permanent magnets (PM) and a structure of yoke is concurrently required. Since the optimization problem becomes large and complicated, it is appropriate to decompose the original problem into sub problems. That is, the IPMSM rotor optimization problem is decomposed into an optimization problem of the structure of yoke under a fixed PM layout condition and an optimization problem of the layout of PM under a fixed yoke structure condition. However, a solution obtained from the decomposed problems is not necessarily optimal at the level of the original rotor optimization problem. In order to obtain an optimized solution at the original problem level, it is necessary to appropriately determine what conditions to be set for variables that are not designed. Therefore, we construct a meta-model relating the solution of topology optimization of yoke structure and the layouts of PM by using response surface methodology. Then, by determining the optimized layout of the PM using the meta-model, an optimized solution is obtained at the original problem level. Numerical example of optimization of the IPMSM rotor is shown. By the proposed method, high performance of average torque is realized.

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This paper presents a reliability-based topology optimization method considering the uncertainty of geometrical variations. Geometrical variations are modeled as an advection of shape, i.e. normalized density, by a random velocity field, represented by a finite number of independent normal random variables, based on the Karhunen-Loève (K-L) expansion. First, the topology optimization method used in this study, i.e. a Heaviside projection method with a partial differential equation (PDE) filter, is briefly discussed. Next, the method for modeling geometrical variations using an advection equation and a K-L expansion is described, and a reliability index for the geometrical variations is defined. The reliability-based topology optimization problem is then formulated using the reliability index, based on the concept of the performance measure approach (PMA), and the design sensitivity is obtained based on the method of Lagrange multipliers and the adjoint variable method. Finally, a numerical example is provided to confirm the validity and effectiveness of the proposed method.

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This paper presents a topology optimization method for unsteady incompressible flow problems using the lattice Boltzmann method (LBM) and level set boundary expressions. In this research, the optimization problem was formulated, the adjoint function and design sensitivety were derived based on the lattice Boltzmann equation. The level set function, a scalar function, was employed to express the material distribution in the design domain. The optimal structure of flow field was obtained with the updating of level set function during the optimization process. Numerical examples to maximize the dissipation kinetic energy were implemented to confirm the validity of the presented method.

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In this paper, we propose a topology optimisation method of sound-absorbing material in two-dimensional acoustics. The sound-absorbing material is modelled with a viscoelastic material, i.e., sound absorption is expressed by the attenuation of the elastic wave (which is excited by the sound wave) due to the viscosity of the viscoelastic material. When dealing with such a model, it is necessary to consider a acoustic-elastic coupled wave problem. Since the problem is categorised in a wave problem in an unbounded domain, the finite element method which is typically utilised in the community of topology optimisation is not the best choice for such a problem, and the boundary element method is employed in this study. In this paper, the optimum design problem of the sound-absorbing material is formulated as to maximise the energy flux on the surface of the sound absorber. After rigorously deriving the topological derivative for the energy flux, we show an example of topology optimisation of a sound-absorbing material. We show that the obtained optimal design has better performance than other con- figurations of equivalent volume with the optimal one, from which we confirm the effectiveness of the proposed method.

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This research proposes a multi-material level set topology optimization method for the design of acoustic devices composed of acoustic media and a multi-elastic-material. First, we explain the two-phase material model that models the acoustic-elastic coupled system without imposing coupling boundary conditions. Next, the level set topology optimization method that can express multi-material distributions, the so-called Multi-Material Level Set (MM-LS) method, is introduced, in which we use two types of level set function. To incorporate the MM-LS method into the two-phase material model, the material parameters used in the two-phase material model are expressed using these two types of level set function. The proposed method is applied to a design problem for an acoustic structure that reduces the sound pressure level. The topological derivatives are computed using the adjoint variable method, and are used to update the level set functions. We construct an optimization algorithm, and numerical examples based on finite element analysis are provided to validate our proposed method.

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In this paper, a topology optimisation method of geometry-independent cloaking devices with several dielectric materials is proposed. In our previous researches, it is shown that cloaking effect of cloaking devices with single dielectric material is highly dependent on the shape of hidden objects and frequency of the incident field. To avoid these problems, it is firstly considered to modify the definition of the objective function in a way that obtained cloaking devices work independently on the shape of hidden objects. Secondly, a multi material topology optimisation method is applied to the design problem of cloaking devices to improve the frequency dependency by extending the solution space. Through a numerical example, it is shown that the proposed method effectively obtain a cloaking device with two materials which works independently on the shape of hidden objects.

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In the automotive industry, weight reduction of car body is demanded for improvement of fuel consumption, and multi-materialization, that is, placing materials such as iron, aluminum and resin in the right place is progressing. Therefore, the tool for implementing concept creation and verification concerning multi-material body quickly in consideration of traits of each materials is demanded. As an effective method, there is optimization of frame structure with ground structure method that enables simultaneous optimization of topology and property using beam element. However, there is currently no way that enables to design material layouts at the same time. Therefore, the objective of this research is to construct systems that enables simultaneous multi-objective optimization of material layouts in addition to topology and property based on the method. This time, basic algorithm was constructed in static rigidity analysis.

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Topology optimization is a powerful design tool for discovering novel and high performance solutions for a given objective, but the obtained optimal structures are often complex to a degree that prevents their manufacture using typical methods such as milling or casting. Due to the recent development of additive manufacturing (AM) technology, complex structures that are too difficult to be manufactured by traditional methods can now be manufactured. Thus, topology optimization has been attracting attention as a suitable design tool for integration with AM processes. However, when optimal solutions are to be applied in practical manufacturing scenarios, engineers must interpret and modify the results to satisfy various manufacturing conditions, even when using AM. During such modification processes, preserving the performances of the original results may be difficult. To solve this problem, manufacturability conditions must be introduced into the optimization process. This paper proposes a scheme for imposing AM-specific constraints, known as overhang constraints, so that optimal configurations that can be built without use of support materials such as struts become available. In the proposed method, the inclination angle of the structures is represented using a fictitious physical model described by a steady-state diffusion equation. Consequently, the overhang constraint can be imposed in the optimization procedure by constraining the value of the fictitious physical field. Several numerical examples are provided to demonstrate the validity and effectiveness of the proposed method.

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Gradient-based optimization algorithms are far more efficient than non-gradient-based optimization algorithms if differential coefficients of an objective function are available in continuous optimization problems. However, in many engineering optimization problems which seem to be continuous, use of differential coefficients are often problematic, because values of an objective function are given by results of simulation runs and it includes numerical errors. Differentiating such values expands the numerical errors further and normal behavior of optimization algorithms is spoiled. Due to the reason non-gradient-based algorithms have important roles in engineering optimization. In this report the author argues an expansion of existing well-known algorithm “Hooke-Jeeves pattern search”. It is discussed that, by introducing some intuitive and clear heuristic mechanisms into the original algorithm, significant performance improvements are easily achieved.

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This study develops the system which assists the unit placement decision of the automatic assembling equipments to assemble efficiently. The unit is a part supply or a robot hand constituting assembling equipment. Conventional research has used reinforcement learning to determine efficient unit placement but this research adopts Genetic Algorithm (GA) instead of Reinforcement Learning. First, as input data, information such as an arrangeable region of each unit is input, and the input region is divided into fixed sizes. Next, the unit is placed in the divided region. Prepare a group of individuals whose genes are the placement of each unit, and repeat selection, crossover, mutation, and evaluation to improve placement. This system introduces the concept of Big Mutation that changes the mutation rate of GA every certain generation. As a result, the possibility of searching for an optimal unit placement increased, and it is expected that the system simulation time is shortened.

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Structural optimization considering stiffener layout has continuous and discrete variables. It is difficult for GA to deal with continuous variable. In order to solve this problem, Hybrid GA made from GA and optimization method being strong in continuous variables is used. This study suggests the optimization method combined GA. The optimization method determines position of stiffener and plate thickness and reduces calculate cost. This structural optimization problem assumes plate thickness constraint. The objective function is minimization of the square of mass of the structure. Updating plate thickness uses displacement formula of plate bending. Updating span uses updating vector of span gotten by searching relation between a change of span and a change of objective function. The updating vector of span similar to gradient vector of steepest decent method. Suggested optimization method is verified by a sample problem. The result of optimization is satisfied the constraint condition. Stiffeners are allocated at regular intervals. As a result, attached stiffeners properly by this method are confirmed.

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When installing a large number of panels on a site with arbitrary shape, there is a panel arrangement that maximizes the amount of power generation per year because the angle and direction of the panel and the amount of received light are different for the installation of the panel. In this study, the optimization technique for the layout design of solar panels is proposed and discussed. The center coordinates and the tilt angle of the panel arrangement are taken as the optimization parameters. Optimization results for several shapes of site are shown and the effectiveness of the proposed method is discussed.

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