This study has attained three two-objective optimum designs of constellation orbit with three satellites specialized for regional coverage observation on the Earth’s ground. Space transportation is becoming more frequent and less expensive due to actively participating by numerous venture companies. Besides, improvements in manufacturing technology and onboard electronics have rendered it possible to promptly and economically fabricate small satellites. Hence, the market in individual cases by multiple small satellites surges from national projects using a single large satellite. However, the design method of constellation orbit specialized for particular local realm observation, which is the purpose of small-scale projects, has not been established. This study describes the six orbital elements of the satellites as design variables; we express the mission as objective functions coinciding with system performance and operation cost, which we perceive as a multi-/many-objective optimization problem. Consequently, the result indicated the correlation between the objective functions and elucidated the profitable operation principle of the three-satellite constellation quantitatively. Furthermore, we accumulated the improvement perspectives regarding the objective-function definition to represent the mission, which the conclusion would procure the knowledge to conduct sophisticating the next-step problem definition.

When mathematical optimization is applied to a multi-objective design problem, it is the common practice of decision support to generate Pareto optimal solutions as alternatives and clarify their trade-offs. The decision-maker selects any design solution according to his or her preferences. Although any comparison of alternatives is beneficial for its selection, in the case of combinatorial design problems, a simple comparison study cannot find the significant relationships between alternatives because of their discrete nature. This paper proposes a decision-making support method based on the dendrogram of hierarchical clustering. It is assumed that an optimal solution can be represented as a piling-up of smaller pieces, which correspond to building blocks, in the combinatorial solution space. The distance of alternatives is surveyed using schema representation defined in various levels. The structure of the solution space is reconstructed into a dendrogram through hierarchical clustering. When essential parts of schemas are identified as building blocks, they are organized into a tree-shaped graph. It is expected to help the designer's exploration into the solution space.

DESTINY⁺ (Demonstration and Experiment of Space Technology for INterplanetary voYage, Phaethon fLyby and dUSt analysis) is a small-sized high-performance deep space vehicle proposed by ISAS/JAXA. The mission of DESTINY⁺ is “Acquisition of small deep space exploration technology, fly-by observation of the asteroid Phaethon and in-situ analysis of interplanetary dust”. To accomplish the mission, it is necessary to optimize the spiral trajectory of DESTINY⁺ to minimize the time of flight, to minimize the fuel consumption and to minimize the maximum eclipse period. In the previous work, when the spiral trajectory design of DESTINY⁺ is optimized, the launch date and time of Epsilon rocket are limited. In this study, multiobjective design optimization of the spiral trajectory is conducted by using multiobjective Evolutionary Algorithms to improve the performance while extending the launch date and time. The present results reveal that the launch date and time can be extended by changing Evolutionary Algorithms parameter.

For the exploration of pit craters, a unique terrain on Mars, the Helicopter is an expected exploration method. In this paper, a multi-objective design optimization is performed in the design range including sharp leading edge and trailing edge shapes to design a rotor blade with higher flight performance on Mars. A combination of blade element theory and two-dimensional computational fluid dynamics was used to evaluate the objective function. The flow fields of the obtained optimal solutions were compared with the flow field of an airfoil with good performance under low Reynolds number, and the characteristics of the airfoil were investigated.

Although it is important to apply thickness constraints to topology optimization problems, it is generally difficult to provide geometric features such as thickness as constraints. In this study, we attempted to formulate topology optimization with local thicknesses by extracting geometric features using partial differential equations and defining new thicknesses from the state field of each point in the object domain. The topological derivative is obtained by setting the constraint function so that the defined local thickness is constant and calculating the associated field based on the adjoint variable method. We conducted a basic study to apply the local thickness constraint to the topological optimization problem, by using this topological derivative for shape updating.

Many methodologies have been proposed to apply the level set method to the representation of multiple phases. In this study, we apply the extended level set method (X-LSM), which is a new multi-phase representation method, to the design problem of compliant mechanisms. The X-LSM is characterized by defining an independent level set function for each combination of two phases, and indicating each domain interface by its zero isosurface. First, we formulate the multi-phase representation by X-LSM and apply it to the multi-material topology optimization problem. Then, it is applied to the design problem of multi-material compliant mechanisms. Finally, the validity of the method is confermed by numerical examples.

Topology optimization is an advanced design method that is used to generate lightweight and high-performance structures by determining the material distribution. However, one of important drawbacks of the topology optimization, especially performed by the density approach, is that distinct and smooth boundaries cannot be directly obtained owing to checkerboard patterns, grayscales and irregular shapes. This drawback make it difficult manufacture the results of topology optimization. In this paper, a novel methodology is proposed to automatically obtain optimal smooth boundaries of topology optimization results using an efficient boundary smoothing technique and H¹ gradient method, which is a node-based parameter-free optimization method. With this methodology, distinct and smooth optimal boundaries can be determined without any shape design parameterization. Moreover, re-mesh is not necessary in the shape updating process and the process is fully automatic. The validity and practical utility of this method is verified through two numerical examples with respect to a mean compliance minimization problem.

Recently, in the aerospace and automotive industries, there has been a growing interest in fiber-reinforced composites, such as CFRP (Carbon Fiber Reinforced Plastic), due to their outstanding specific strength. However, such materials have anisotropic properties that their strength depend on the orientation of fibers. Therefore, handling this anisotropy into topology optimization can bring new possibilities to the use of fibrous materials. In the present work, we propose a topology optimization method that maximizes the dynamic stability of fiber-reinforced composite structures by simultaneously optimizing the density distribution and the fiber orientation.

In this paper, we present a basic study on multiscale optimization for electromagnetic metamaterials using high contrast homogenization method. High contrast homogenization method can evaluate the behavior of waves at resonance, but high contrast homogenization method is not effective for structures that have unconnected matrix materials. In this study, we introduce a geometric constraint such that the matrix materials are connected in order to obtain an optimal structure within the range where the high contrast homogenization method is effective. In numerical examples, we demonstrate the effectiveness of the geometric constraint.

In this paper, we present a shape optimization method for periodic microstructures to maximize a specified vibration eigenvalue of a porous macrostructure. The homogenized elastic moduli calculated by the homogenization method are applied to the macrostructure to connect the microstructures with the macro structure. The KS function is introduced to solve the repeated eigenvalue problem hidden in vibration eigenvalue optimization. The shape optimization problem subject to the volume constraint considering the microstructures is formulated as a distributed-parameter optimization problem, and the shape gradient function is derived by the Lagrange multiplier method and the adjoint variable method. The shape gradient function is applied as a distributed force to update the design boundaries of the unit cells of the microstructures by the H1 gradient method. The smooth boundary shapes obtained by the H1 gradient method are suitable for manufacturing with a 3D printer. In the numerical examples, the eigenvalues and the optimum shapes were compared changing the number of the domains of the microstructures in the macrostructure. As a result, the effectiveness of shape optimization method for microstructures aimed at maximizing the vibration eigenvalue of a macrostructure was confirmed.

In this study, we propose a concurrent shape optimization method for stiffness design of porous multiscale structures. The macrostructure is divided into several arbitrary domains, which have independent periodic microstructures. We optimize the shape of the macrostructure, the shapes of the voids distributed in the microstructures periodically and the boundary shapes of the interfaces between the domains. In order to bridge the macrostructure and the microstructures, the homogenized elastic moduli are calculated using the homogenization method, and applied to the elastic modulus of each domain in the macrostructure. The compliance of the macrostructure is minimized under the constraint conditions of the whole area of the macrostructure including the microstructures, the area of domains, the state equation of the macrostructure, and the homogenization equation of the microstructures. The sensitivity functions distributed on the design boundaries are derived using the material derivative of the Lagrange function. We use the H¹ gradient method to obtain the clear and smooth boundaries.

In this paper, I proposed an educational support design method that enables learners to agentic aware skill information when learning skills that involve physical movements. First, skill information is collected by the skill information structuring method proposed by the author, and structuring is performed in consideration of the effect on the quality of the deliverable. Next, I proposed a new method for designing a learning program by selecting presentation information and evaluation items according to the learning process of physical skills. Here, the presentation information and the evaluation information are fed back so that the learner can agentic aware the important physical control factors and somatosensory factors in the skill movement. In the future, I will develop a system for extracting information and creating learning programs, and study learning efficiency and learning process.

The nature of design is progressive reduction of uncertainty that arises in its process. Designers drive design activities to reduce uncertainty, aiming to derive a design solution that is considered appropriate for requirements through trial and error. However, in co-design, where heterogeneous designers with different backgrounds, beliefs and knowledge participate, uncertainty can be non-monotonically variable due to the differences in nature and degree of uncertainty each designer perceives. Therefore, it is necessary to proceed with design activities under a converges the differences in their uncertainty perception through sharing the contents of uncertainty and its rationale that explains why the designer perceives that uncertainty. This study aims to develop a practical method to support the consensus-building of design activities considering the uncertainty in co-design. As an initial stage of this study, this paper firstly defines uncertainty under the context of co-design through literature review of extant researches related to uncertainty in design. Then, we discuss about the matter that should be shared among designers for consensus-building of design activities.

Due to the recent improvement in the social living standard, products/services are required to realize a high value for users. Because the value of them are subjectively evaluated based on the perceived function of users, the designers should improve their value through the circular design process, in which designers repeatedly reflect on and redefine designers' provided functions by referring to users' received functions. However, previous functional modelling methods have not addressed the comprehensive structure of functions that clarifies the relationship between provided functions and received functions. This gap causes the difficulty to capture the consistency between these functions, thus, the designers struggle to practice reflection and redefinition of provided function logically. Based on aforementioned background, this research clarifies the comprehensive structure that enables phenomenological understanding of the relationship between provided functions and received functions. Then, this research develops a method to identify the inconsistency between received and provided functions by modelling the comprehensive structure of their functions in a formal procedure. The proposed method consists of a receive-provide structure modelling framework and its usage process. This study refers to previous studies on the view model and the function-behaviour-state diagram as the theoretical basis for building the framework and enabling designers to capture the integrative of designers and users. The proposed method was applied to a closed water district environment improvement service, and this result demonstrated that the proposed method can describe the process by which designers reflect and redefine their provided functions from their users' perspectives.

In order to reduce CO₂ emissions from multimodal transportation systems consisting of automobiles and public transportation, it is desirable to realize modal shift from automobiles to public transportation. Conventional life-cycle CO₂ assessments of a multimodal transportation system has not sufficiently considered the modal shift of transportation demand. In this study, the distribution of travel demand to public transportation was calculated by macro traffic simulation in which the traffic flow was regarded as continuous fluid, and its calculation results were reflected to the life cycle simulation. The CO₂ emissions of transportation system in Suita, Osaka was calculated by the developed models and evaluated by four modal shift scenarios including two extreme scenarios. In the results of a case study, promotion of bus use, reduce about 6% of CO₂ emissions.

This paper aims to develop a planning support method for sustainable woody biomass energy business. The problem is that current practices are done by professional consultants and knowledge used for planning of woody biomass energy business tends to be implicit and less systematized. To formalize the planning process, we conducted interviews with business practitioners and field surveys. Based on the results, we developed the list of planning items that need to be considered. Moreover, because future uncertainties are critically influential on the sustainability of the business, we applied scenario analysis to business planning. To demonstrate the proposed method, we carried out a case study in a mountain forest area in Japan.

In industrialised countries, the competitiveness of the products/services of the manufacturing industries in the global market is declining due to many factors, including products commoditization and rapid technological growth in developing countries. For this reason, engineering designers in industrialised countries are required to enhance their creativity in design with redefining customer value and redesigning advanced solutions. In recent years, the design thinking, which is known as a practical method for user centered creative design, is attracting attention as a practical strategy to accelerate creative innovations in engineering design. However, the logical details in designers’ cognitive process are still not clear, which hinders the practice and dissemination of design thinking. Based on above background, this paper proposes a prescriptive cognitive process model that leads highly creative engineering design. The proposed model is constructed based on the analysis of characteristics of exist engineering design process models and findings from creative thinking processes derived in cognitive science domain. The proposed model comprises following five steps: requirements finding, design solution finding, verification, validation, documentation, and implementation. The proposed model was applied to analyze a bicycle design case, which is a past actual example that achieved highly innovative design. As a result, the application result demonstrates that the proposed model can explain the mechanism of creative engineering design process and be expected to promote creative engineering design.

Abandoned babies and baby dumping cases are one of the most crucial problem in Malaysian communities. Despite the existence of the 24-hour helpline and the baby-hatch, the baby dumping cases remained increasing yearly. One of the reasons is the unwillingness of the baby’s parents for their identities might be discovered if they used the helpline or the baby-hatch. Therefore, in this paper, a team consisted of Japanese and Malaysian students in Model Based Creative Design project suggested a solution for this problem by initiating the idea to create an autonomous carrier for saving abandoned babies. This autonomous carrier will move autonomously once the baby was placed safely at one drop point to the closest hospital/orphanage. The idea was then validated by identifying needs and awareness thru survey, searching for similar idea/invention in research paper, journal and patent, designing the concept and prototyping the design of the autonomous carrier. The prototype of the autonomous carrier was named “Keep the Baby Safe. It is hoped that this idea will be utilized and the parents that wished their identity to be remained unknown will be benefitted and will reduce the number of baby-dumping cases in Malaysia.

The lean experts have defined 7 types of wastes in an industry, i.e., inventory, overproduction, process, rework, waiting, transport, and unnecessary motion. In this study, the researchers have focused primarily on 2 kinds of wastes, i.e., inventory and transport wastes. A company can face 2 major issues, where they have an insufficient storing capacity and possess a higher moving time of their sub-assembly components. Lean Manufacturing (LM) is used as a common solution for eliminating wastes in industries. The researchers have presented an example of a door hardware casting company, operating in Malaysia, which used the First In First Out (FIFO) design as a solution for improving their storage capacity and decreasing the moving time of their sub-assembly components. They implemented the PDCA (Plan-Do-Check-Action) approach, and used LM tools like the Ishikawa diagram and 5S, for further assisting the FIFO system. The researchers aimed to investigate the existing system implemented in the company warehouse, and thereafter design and implement an effective FIFO system for solving the issues affecting the warehouse. Here, the researchers primarily investigated the sub-assembly components that were used in the indoor warehouse. Before they implemented the FIFO design, they studied the actual situation in the company warehouse using methodologies like brainstorming sessions, observation, semi-structured interviews, and referencing secondary sources. They proposed the new FIFO system and redesigned the warehouse. The design tools that were included were the Morphological Charts, concept screening and concept scoring. A new Standard Operating Procedure (SOP) was proposed. Thereafter, the FIFO system was verified and validated by comparing the results before and after its implementation. The use of the FIFO system helps in increasing the storage capacity and decreasing the moving time of the sub-assembly components. This further helps in decreasing the inventory and transportation wastes.

The trade-off relationship between speed and accuracy has been well known in many types of motor tasks. An error of a movement increases as the speed of the movement. Previous investigation by computer simulation suggested that negative viscous blocks the trade-off relationship. In this study, actual human movements on viscous fields were measured to investigate the effect of viscous on the relationship between speed and accuracy. A reciprocal hand movement specified some accuracy and amplitude of the movement was examined. Main findings of this study were as follows: (1) The speed accuracy trade-off is also applied to the reciprocal movement on the negative viscous field, (2) movement variability of the non-dominant hand is larger than the other hand, (3) the dominant hand well exploits the dynamics condition according to a motor task than the other hand, (4) participants can produce faster movements on the positive viscous force field, and (5) the slope of the regression line based on the Fitts’ law implies adaptation and prehension to the dynamics of the current working space.

Although the teleconferencing system is widely used today, fundamental problems such as the inability to share the mood of the place have been pointed out. Therefore, further technological innovation is required. Previous studies of the authors showed that the active display of a tablet using the head-motion of a subject was recognized as generally positive. However, motion parameters settings for appropriate active display is an open issue. This study focuses on the sensitivity evaluation using a virtual active display system to obtain the appropriate motion parameter. This paper describes the development of the virtual display system prototype and reports the on-going evaluation experiments.

This study proposes an IoT-based health management system using an AI speaker integrated with a desk-side projected avatar for general users including those who are not familiar with information devices operation. The user interface of the health management system integrates an AI speaker for voice operation to manage daily personal activity data obtained from a wearable device. The avatar integrated to this system makes an interactive motion based on the analysis of the sentences spoken by the user in inquiry talk and the AI speaker in response answer. This paper covers the research background of this study, followed by the overview of the system concept proposed in this study, development of a prototype system based on the concept, preliminary test of the prototype developed in this study, and the future work of this study.

This study proposes an evaluation method based on Kansei Engineering to clarify the primary factors that could affect to the impression of bottle shape and label design of PET bottle. Focused on the PET bottles of natural waters only, this paper classifies them based on a clustering method using physical shape and label design features, evaluates them using Kansei engineering techniques, and determines the design parameters using Preference Set-Based Design (PSD) analysis to clarify the primary factors of impression. First, PET bottle samples and their derivative bottles are prepared/generated to cover diversity of PET bottle design, and cluster analysis is performed them to classified them to representative categories. Kansei evaluation to these samples in each category is performed by a variety of subjects online/offline and its Kansei evaluation is performed to clarify the impression of PET bottles. In order to eliminate the bias of the subjects, cluster analysis is performed to classify the subjects into representative categories with similar preferences to PET bottles. Finally, PSD analysis is performed on each classified cluster to clarifies the primary factors that could affect to the impression of bottle shape and label design.

The technology-oriented strategy of the manufacturing industry, which supported Japan's international competitiveness in the 1990s, lost its competitive advantage due to the expansion of market globalization and the rapid technological improvement of emerging countries. What has emerged since the beginning of the 21st century has been the information technology industry, which has succeeded through market-pull innovation strategy represented by Big Tech or Big Four (GAFA). In order for products and services to have novelty and superiority in the market, it is important to grasp the latent needs obtained from users. Latent needs are defined as "those that many customers recognize as important but cannot be clearly stated in advance." Various surveys in the discovery of ideas aim to uncover latent needs, but the conditions and factors that can obtain the latent needs are unspecified. Therefore, in our research, prototype-based interviews were conducted to a focus group of men and women who had childcare experience. The interviews were regarding the effect of the covid-19 pandemic to their daily life including childcare and housework. The non-prototype interviews were also conducted to compare and elucidate latent needs. In the interview results and their interpretations, it was found that while the information presented in the prototype-based interview leads to eliciting new needs, but it may narrow the range of thoughts and opinions on the user side. In the future, it will be necessary to further verify and improve the effectiveness of the method through the overall execution of the innovative design methodology.

Traditional design course in Japan has been based on knowledge and efforts have been paid to educate students. As the current computer processes cardinal numbers, engineering today processes knowledge in Euclidean Space. But Euclidean Space requires datasets to be orthonormal and interval scale (with units)-base. These courses worked very good, because changes were smooth yesterday and we could predict the future. But today, environments and situations change not only frequently and extensively, but in an unpredictable manner. So, design education based on past experience does not work anymore. We need to develop a new framework for design. The greatest change is experience used to be a thing of the past, but today we need to create experience. We need to design or plan what we should do and search how we can perform it by trial and error. So, design will be truly creating the future. It is to make our dreams come true. Design courses yesterday were tactics. You learn how to use these tools, because the goal was fixed from the first. But design tomorrow will be exploring the new frontiers. We need to find a new market, a new product. But the resources are limited. So, as American President and explorer Theodore Roosevelt told us, we need to “do what we can, with what you have, where you are”. Design tomorrow will be nothing other than exploration. We need to find new horizons. Thus, design will be design engineering and we create a new society. And this new society is not only self-sustaining, but also self-satisfying. The new design will focus on humans instead of machines.

Online lectures on system design, mechatronics, CAE, AI, IoT, telemetry/control, and programming techniques necessary for the design and development of robots for new lifestyles were given to engineers, researchers, and managers of small and medium-sized companies, and exercises, practical training, and discussions were conducted. In addition, we organized groups of seminar participants from different industries. Each group was assigned a task of robotics, and practiced robotics design and manufacturing in a comprehensive practical training. The students acquired knowledge and practical skills related to robot development through presentations of the results of the tasks and discussions.

In Japan, design education is focused on product design. In short, the goal is given and how we solve the problem is taught. It is tactics. But today the environments and situations change drastically. Changes yesterday were smooth, so we could predict the future. But today changes are sharp, so we cannot predict the future. Yesterday, our world was closed with boundary so we could easily identify parameters and could apply mathematical approaches. But today, our world is open world without boundary, and it is expanding rapidly. Further, materials are getting softer and softer, so direct interaction becomes critical. Therefore, we need to develop processes to cope with these changes. Therefore, planning and process development become increasingly important. To describe it another way, strategy and decision making become critical. We need to find our goal by trial and error. To achieve this, we need to develop creativity capabilities, and there is no other way but self-learning.

The Real World is changing rapidly and extensively. Yesterday, changes were smooth, so we could differentiate them and predict the future. But today changes are sharp, so we cannot predict the future. Yesterday our world was closed with boundary, but today it is an open world. Thus, yesterday we could apply mathematical approaches in a straightforward manner in a Euclidean Space, which requires datasets to be orthonormal and cardinal scale based with units. But we cannot satisfy these requirements today. The Real World becomes too much complicated, and datasets are now composed of wide varieties of information. Therefore, traditional Euclidean Space approaches do not work anymore. Furthermore, materials are getting softer and softer. Until now, objects were hard, so we could easily understand how we should handle them, with vision alone, even from a distance. But with the remarkable progress of material engineering, objects are getting softer and we need to directly interact with them to find out how we should deal with them. In short, we have been paying efforts to solve the problem, with the goal fixed from the first. It was tactics. But now to cope with the rapidly and unpredictably changing the Real World, we need to find the goal. Strategic decision making becomes important. And although mind accommodates body and brain, it is the body that directly interact with the Real World. And the brain processes these accumulated pieces of past experiences. Thus, mind, or to put it short, instinct becomes crucially important. Mahalanobis Distance-Pattern (MDP) Approach is proposed as a new Non-Euclidean Space approach to tackle the problems which cannot be solved with the traditional Euclidean Space approaches. The uniqueness of MDP is Ordinal number based and pattern is used for nonverbal communication.

Bimetal composi te structures have potential applications as parts or components in automobile, aircraft, marine engineering to satisfy specific requirements because of the combination of different material properties of metals. In the present work, to control the vibration behavior of bimetal composite structures, we propose a free-form optimization method based on the H¹ gradient method to optimize the interface shapes of initial stressed composite structures composed of dissimilar materials. External forces are acted on the structures to generate the initial stresses, and the bandgap between different order of eigenvalues using weighting coefficients are set as the objective function, which is maximized under the volume constraint. From the design example, the developed shape optimization method has efficiency and validity to design bimetal composite structures with large bandgap for vibration control.

By placing special periodic structures called acoustic metamaterials or acoustic metasurfaces in the sound propagation path, it is possible to control the acoustic properties. However, the shape of the periodic structure with the desired acoustic properties is complex and not easy to design. In this study, a topology optimization method using the level set method is used to design a structure that guides sound waves propagating parallel to a flat wall into a specific space. A structure with better acoustic properties than the aperiodic structure was obtained. The obtained structure has multiple projection shapes, and it was confirmed that the direction of travel can be controlled for sound waves with a wide range of frequencies.

In this research, we present a level set-based topology optimization method for acoustic structures considering the boundary layer effects. It is widely known that acoustic waves propagating through narrow channels are affected by the viscous and thermal boundary layers. To consider such effects, we introduce a sequential linear Navier-Stokes (SLNS) model. First, the SLNS model is briefly introduced. Next, an optimization problem is formulated, where we set the absorption coefficient as an objective function. Based on the concept of the topological derivative and adjoint variable method, we derived a design sensitivity. A two-dimensional numerical example is provided, which supports the validity of the proposed method.

Biphysical cloaks that can manipulate both electromagnetic and acoustic waves are optimally designed by a topology optimization based on covariance matrix adaptation evolution strategy. The presented method explores optimum sets of level set functions which express the structures of biphysical cloaks for minimizing three objective functions on the scattering of E and H polarized electromagnetic and acoustic waves. We solve two Helmholtz equations derived from Maxwell’s equations evaluating the performances of electromagnetic cloaks and solve an acoustic-elastic coupled problem for evaluating the performance of acoustic cloak.

There are several problems such as noise and performance degradation in industrial transformers. In transformers, coils and iron core are distorted by magnetostriction and induce vibration. The vibration generates the noise on the boundary surface of them. And the vibration causes deterioration of the performance of the transformers. In order to reduce the noise and avoid the deterioration, we need to estimate the vibration characteristics of transformers at the design phase. The natural frequency analysis using finite element method is an essential process to estimate the vibration characteristics. However, it is very difficult to identify the material constants of the iron core because this material is composed of many thin plates. And although a laminated material made of thin plates can be regarded as a linear anisotropic material, its material constant cannot be theoretically estimated. In this paper, we verified the accuracy of the first derivative calculated based on adjoint variable method. The first derivative of a natural frequency with respect to material constant is derived based on the adjoint variable method. In this method, the first derivatives can be calculated by using the result of a finite element analysis and some additional operations. And we believe that the material constant identification problem can be solved efficiency by using the first derivatives. It is necessary to check the accuracy of the first derivatives when we solve the problem by using the first derivatives. So, we verified the accuracy of the first derivatives by comparing the amount of change in the natural frequency of the target equipment estimated based on first derivatives and the amount of change in the natural frequency of the target equipment calculated by the results of finite element method analysis.

Shape and topology optimization of the structure subjected to pressure load requires maintaining the smoothness of the boundary at which the pressure load is applied during the optimization process, and the direction of the load position changes with the variation of the boundary. Therefore, it is a difficult structure optimization problem. In this paper, we present the simultaneous shape and topology optimization method for the pressure load problem. In this method, optimization of the boundary subjected to the pressure load is set as a shape optimization problem by the H¹ gradient method, and the optimization of the other design region is set as a topology optimization problem by the level set method. With the proposed method, the light-weight structure can be obtained while maintaining the smooth of the boundary shape to deal with the pressure load problem. Two design problem is presented to confirm the validity and the practical utility of the proposed method.

Thermal metastructures designed by topology optimization are demonstrated in experiments for invisibility cloaking and invisible heat flux focusing. Our demonstrations exhibit the capabilities of two topology-optimized metastructures, specifically, a thermal invisibility cloak that makes an obstacle thermally invisible and a thermal cloak-concentrator that focuses heat flux without disturbing the outer temperature, as well as their performances. These metastructures are composed simply of steel and copper and their spatial arrangements are optimized through topology optimization without any meta-materials. Moreover, both metastructures were easy to fabricate. Their promising performances in the steady states are verified in not only numerical simulations but also experiments.

Header in the heat exchanger has an important role in industry, which pressure drop as well as flow distribution be simultaneously improved. In this paper, a multi-objective design optimization for minimizing the standard deviation of liquid flow and the pressure drop is performed using numerical simulation. Numerical simulation in computational fluid dynamics (CFD) is so intensive that sequential approximate optimization using radial basis function is adopted for the design optimization with a small number of simulations. Through the numerical result, the pareto-frontier between the standard deviation of liquid flow and the pressure drop is clarified. In addition, it is confirmed that the angle of perforated plate reduces vortex which have a significant influence on the flow maldistribution.

In plastic injection molding (PIM), weldline affects the strength and surface quality of products, and it is then important to determine the optimal process parameters for the weldline reduction. Rapid heat cycle molding (RHCM) that actively controls the mold temperatures is an effective PIM technology to weldline reduction, but requires long cycle time. In this paper, variable pressure profile that packing pressure varies during the PIM process is incorporated in the RHCM in order to shorten the cycle time. To determine the process parameters including the mold temperature profile in the RHCM, a multi-objective design optimization is performed. The mold temperature is maximized for the weldline reduction, whereas the cycle time is minimized for high productivity. Numerical simulation in the proposed RHCM is computationally so expensive that sequential approximate optimization that response surface is repeatedly constructed and optimized is used to identify the pareto-frontier. Based on the numerical result, the experiment using PIM machine (MS100, Sodick) is also conducted to examine the validity of the proposed RHCM.

It has been a long time since the food industry has been required to comply with HACCP and FSSC 22000 standards, but various devices are required to have appropriate qualifications based on critical control points. Rare earth magnets used in magnetic separators are demagnetized due to deterioration over time and the environment in which they are used, so it is necessary to confirm performance qualification. Therefore, in this study, we performed static magnetic field analysis on the relationship between the desired surface magnetic flux density and demagnetization using Maxwell's equations, calculated the surface magnetic flux density and permeance coefficient from multiple patterns of magnetic arrangement, and depended on aging deterioration and operating temperature. Made it possible to predict demagnetization. As a result, Operation Qualification becomes possible, and quality assurance of products and danger avoidance can be realized.

We have developed the interactive design support technology in order to efficiently obtain finding of lightweight-car-body structure with high performance. The challenge with this technology is nonlinear contribution analysis with a small number of samples, a large number of variables and strong nonlinearity. In addition, complex results by nonlinear contribution analysis makes it difficult to provide engineers knowledge in weight reduction. To solve these problems, we propose the nonlinear contribution analysis method that combines the technique to derive non-linear basis functions using the evolutionary computation and sparse modelling using selection probability of factors. Additionally, we also apply the post processing that excludes factors difficult to interpret based on engineering viewpoint to analysis result. This method indicates high accuracy and robustness with a small number of samples, and the post processing decreases the number of terms in the model while maintaining high accuracy and improves interpretability. As the application result to car body structure problem, this method is shown to be effective in discovering bottlenecks and knowledge in weight reduction.

We propose the dynamic visualization method using load transfer analysis (U*).It is important to find an effective countermeasure structure by analyzing the causes of the bottleneck about car body stiffness for weight reduction. Important parts of car body stiffness are bottlenecks for weight reduction in automotive product development. As a method to predict the load transfer, load transfer analysis (U*) has been proposed. However, it is difficult to predict the load path only from the contour lines of U* values for complex structures such as car body structures. Therefore, we propose the dynamic visualization method that divides the U* value evenly and visualizes it continuously and dynamically from 1.0 to 0.0 in U*. This method expresses artificially the load transfer flow and make designers and engineers find weak structures based on the difference from the designer's concept or hypothesis in automotive body design. As a result of applying this method to car body structure for body stiffness, it was found that the weak points were concentrated in the parts on the side of the vehicle structure. Furthermore, by changing the joining method of the side parts of car body structure, we were able to improve the load transfer flow of U* and found the structure that was 9kg lighter than the base structure, subject to body stiffness, side crash and low frequency eigenvalue.

In this research, a product family design concept is addressed from the product conceptual stage. For this reason, a product family design system and method is proposed to serve as a tool to represent entire product functions．The product family design method is to improve the efficiency of development and production while responding to diversifying market needs．The existing major components are shared and their combinations are considered. n this way, it is possible to respond to various needs with a lump-sum design by both reducing the number of parts and increasing the variety of products．In order to verify the effectiveness of the proposed method，a model lineup is generated and its performance is evaluated by the product family design system based on customer requirements for an autonomous exterior wall repairing device. In this paper, detailed structures of the design system are presented and its performance is compared with that of the conventional design results. As a result, the proposed product family design system contributes to achieve the performance to cover a wide range of customer requirements and reduce the number of component types compared with the conventional design.

Spacecraft automatic docking systems need to achieve high level of reliability, robustness, and safety. On the other hand, it is difficult to realize comprehensive evaluation and verification only by ground test due to issues with reproducibility of actual operation condition in the space environment. Therefore, model-based development method and framework targeting the spacecraft automatic docking system to realize efficient and reasonable analysis and evaluation regarding feasibility and safety have been constructed in Japan Aerospace Exploration Agency. This model-based development framework consists of off-nominal scenario identification based on model-based systems engineering method from safety point of view and evaluation of dynamic behavior with multi-physics and system-level integrated modeling and numerical simulation.

In this paper, we propose a defect cause analysis method that can automatically derive possible causes without relying on the experience of engineers, and can extract causes difficult to predict. First, events and their causal relationships are modeled with Petri nets. In addition, an assembly model is introduced to represent the propagation of events between parts. Next, a method to predict causes of product defects using the causal relationship model and the assembly model is proposed. In the method, a product model including not only its functions but also its manufacturing process is created at first. Then, past event causal data related to events in the product model are combined to the model. After that, a defect cause prediction model could be generated by reversing the relationship between cause and effect. By using this model, a cause event of a product defect can be traced step by step. Thus, possible underlying causes of the product defect is automatically derived. Finally, we confirmed the usefulness of our proposed method by implemented a system and predicting causes of a defect of an electric drill.

This study proposes a framework to acquire and manage knowledge about the modeling rationale for model-based development with a multi-domain modeling language. The proposed framework utilizes the three-layered process model, which integrates the representation of design states, design transitions and rationale, and records them as a by-product of operations on the representation of the design object. An ontology of design objects and design operations is a key of the framework. This study defines it based on the library of Modelica, which is a typical example of a multi-domain modeling language. The proposed method is applied to the modeling process of a vibration analysis of a hair dryer to verify its effectiveness.

Cellular automata calculation of mechanical fields was a major research objective of my studies for past five years, although it is not a whole goal of the study, which aims building a computational instantiation of emergence property in design. And in this report it has achieved successfully by Multiple-Layer Multiple-Frame (MLMF) scheme, jus. Before arguing MLMF scheme, I will summarize basic properties and achievements of preceding three cellular automata formulations : Single-Layer Single-Frame (SLSF), Single-Layer Multi-Frame(SLMF), Multiple-Layer Single Frame(MLSF), then the latest MLMF formulation will be stated as a conclusion of a series of evolutions of cellular automata formulations. Finally research plans of building emergence computation, which was originally considered, will be updated and posed briefly.

It is said that the relationship between “novelty” and “aesthetic liking” is expressed as an inverted U-shape. The latest studies about perception emphasize “novelty” as a factor of emotion and quantify “novelty” by assessing the difference in amount of information using Kullback-Leibler (KL) divergence. The previous research quantified “novelty” of curved surface shapes using KL divergence and carried out the sensory evaluation using shapes of an automobile. This research incorporated the concept of location information into KL divergence. The result indicates the correspondence of KL divergence to perceived “novelty” (the determination coefficient is 0.53). However, an inverted U-shape relation was not observed between “aesthetic liking” and KL divergence. This seems to be caused by the mere exposure effect occurs about the shapes with low KL divergence. Furthermore, the small range of KL divergence seems to result in less tendency of the theory in aesthetics.

This paper described the expression method using Multispace design model for emergent design, which is positioned as a design methodology in Design science. Specifically, we focused on the AGE thinking model, knowledge space, Value space, Meaning space, State space, and Attribute space in Multispace design model, and considered the details of emergent design due to the difference in thinking paths between spaces. As a result, multiple types of thinking paths were shown, which helped to construct a framework for design methodologies.

“Sharing Economy” has been attracting a lot of attention as an economic activity in which products and service are shared among the stakeholders. However, the standards and design methods for the sharing economy have not been established. Additionally, the sharing economy has a particular characteristic in which peer shares with other peers, called P2P service. In the P2P service, the design of the "sense of trust" which is considered to be an important. This study, therefore, analyzes the previous studies and existing sharing economy to clarify the patterns of actor's activity in the P2P services and to identify the differences in the trust that P2P services provide to Peers. The result shows that there are two types of services in the sharing economy: services where Peer trusts Peer and services where Peer trusts the system. Finally, based on the classification of trust factors, this study provides guidelines for identifying rules of design for the sharing economy, such as the different types of trust required for different objects to be shared.

In this paper, we propose a new unfolding method for a trimmed NURBS surface. We generalize our unfolding method by evaluating the geometric properties along the trim curves on the target NURBS surface. Even in the case of trimmed NURBS surfaces, we can properly compute two patterns of developments by treating the trim curves as like unfolding reference lines. We applied the proposed method to a complex free-form surface of an electric vertical take-off and landing and evaluated the effectiveness of the proposed method by assembling paper-craft scaled models. Using our method, we can compute developments of a complex topological shape represented by trimmed NURBS surface.

In the field of automotive style design, reverse eingineering technology that automatically generates CAD (Computer Aided Design) data from measurement data is gathering attention. In order to apply it for practical use, it is necessary to fit a suitable trimmed surface to the triangle mesh data given as measurement data. Especially in the design , it is important functionally and design-wise that the boundaries of the fitted trimmed surface are smoothly connected.

In this study, we propose a trimmed surface fitting method that G¹-continuity for the triangle mesh given as measurement data, and describe details and results of own method.