[in Japanese]

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Supersonic aircrafts experience intense flow-characteristic changes because of shock waves while they are passing through the transonic flow region. These anomalous changes can cause dangerous aeroelastic problems, such as flutter. Hence, it is very important to design an aircraft to be able to avoid the aeroelastic instability. In this study, a nonlinear aeroelastic analysis system is developed using coupled numerical techniques of computational fluid dynamics (CFD) and computational structural dynamics (CSD). For efficient computation, the structural dynamic solver of the developed system is based on the modal approach, and aerodynamic solver is based on the modified transonic small-disturbance (TSD) equation. Detailed aeroelastic simulation results in transonic and supersonic regimes are provided to show the aeroelastic characteristics of several aircraft models. In addition, a discussion of how to apply this technology to the actual design process of high-performance aircraft is presented.

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Anisotropy of wood and wood-based materials are summarized. Wood has characteristic anisotropy arisen from its fibrous structure approximately regarded as three-dimensional orthotropy. Commercial structural lumber is assumed more simply as a two-dimensional orthotropic material for convenience of practical structural design. Anisotropy of wood is a good property for structural members to bear stresses parallel to the wood grain. However, it is undesirable in some other cases. One effective way to modify the anisotropy of wood is to reconstitute wood veneers, pieces, particles or fibers with adhesives. Anisotropic wood, on the other hand, is a satisfactory structural material with no serious trouble, if the structural designers understand its anisotropy and utilize it appropriately. An essential element of using wood as a structural material is appropriate design of structural joints considering anisotropic mechanical behavior of wood.

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This paper proposes a new design optimization by integrating an evolutionary search and a cumulative function approximation. While an evolutionary search has an ability of global search even under multi-peaks, rugged natures, etc., it requires much computational cost. While a response surface technique can save computational cost for complicated design problems, the fidelity of solution is affected by density of samples. The proposed method simultaneously performs these two methods. In its early phase, it searches roughly but globally approximated surfaces with relatively small number of samples, and in its later phase, it searches intensively around promising regions over response surfaces enhanced with additional samples. It is implemented with a real-coded genetic algorithm and a Voronoi diagram based cumulative approximation, and it is applied to several numerical example problems.

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This paper discusses global approximation in the context of multidisciplinary design optimization and proposes a response surface method with third-order polynomial with optimal selection of interaction terms. After the necessity and role of global approximation are reviewed, the indices of approximation model, computational cost, width of design region and fidelity of approximation model, are described. The discussion brings a potential of high-order polynomial approximation among their tradeoffs. Following them, a method for establishing third-order polynomial regression model is formulated. The method consists of design of experiments, Chebyshev's orthogonal polynomial, optimal selection of interactive terms with a genetic algorithm under the criterion of 95% confidence limit. Its application to some test functions demonstrates the effectiveness of high-order and interaction terms.

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Distributed Probabilistic Model-building Genetic Algorithm (DPMBGA) is new model of Genetic Algorithm. In the DPMBGA, when the offspring is generated, Principal Component Analysis (PCA) considers the correlation among the design variables. Moreover this model applies island model to maintain the population diversity. The effectiveness of DPMBGA has been demonstrated by using continuous functions. However parameters of DPMBGA such as Amp or Sampling rate has not been considered yet. Therefore this paper shows consideration of the parameters in the DPMBGA.

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This paper discuses the performance of parallel genetic algorithms. Master-slave model is one of implementation models of GAs. In the most cases, the significant scale up is derived by using a master-slave model. However, the optimum number of process is existed and this number is decided by the relation of computational time and communicational time. In this paper, this optimum number of process is analyzed. At the same time, this analysis is confirmed through the experiments using PC cluster system.

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The pervasiveness of micro processor units (MPUs) in mostly controlled system coupled with recent rapid advances in MPU technology have created both benefits and problems. One of the problems is that it takes more man-hours to develop a program of a automatically controlled system. Our research group has developed and offered the method to support to design such a control program, thus requiring fewer man-hours, using evolutionary computation such as genetic algorithm (GA) and genetic programming (GP). However, there is no clear policy how to select the gene expression and how to design a fitness function in order to apply evolutionary computation to air conditioning system. In this paper, the method of selecting fitness function when the evolutionary optimization is applied to air conditioning is described.

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The robust structural optimization algorithms of a plate whig is proposed considering the bifurcation hi higher mode flutter, which affects the robustness of an optimum design and the convergence of an optimization. To improve the critical dynamic pressure of supersonic flutter under the constant total mass, the thickness distribution of a delta whig is considered as design variables. The constraints are proposed of keeping eigenvalues between adjacent modes apart by the specified distance which is composed of the sensitivity of the distance of eigenvalues. The numerical results indicate that the robustness of the optimum design is quantitatively obtained with the constraints.

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This paper examines stacking-sequence optimization design for improving the transonic flutter limit To reduce the required computational cost, application of the Fractal Branch and Bound Method is attempted This method is proposed by the authors for the stacking-sequences optimization of laminated composites in order to maximize the buckling load, and it demands approximation of a design space with a response surface comprising quadratic polynomials for pruning branches of stacking sequences. To approximate with appropriate accuracy the discontinuities of the design space of transonic flutter due to flutter mechanism change between the classical flutter and the Limit Cycle Oscillation, a combinatorial approximation method using the modified response surface method is proposed The applicability of the proposed stacking-sequence optimization procedure using the Fractal Branch and Bound Method is demonstrated by applying it to the stacking-sequence optimization design of an AGARD 445.6 standard wing. The results indicated that the method was applied successfully and that therefore a practical optimal stacking sequence could be obtained with significantly low computational cost

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Fractal branch-and-bound method has been developed by the authors for the optimization of stacking sequences of symmetric and balanced composite laminates that has two in-plane and two out-of-plane lamination parameters. In the present study, a stacking sequence optimization of an unsymmetrical composite laminate is examined. In the unsymmetrical laminates, nine lamination parameters including three coupling lamination parameters are not zero. Using tetrahedral fractal patterns of feasible laminates of in in-plane and out-of-plane lamination parameter coordinates, and a tetradecahedron fractal pattern of a coupling lamination parameter coordinates, fractal branch-and-bound method is applied to optimize the stacking sequence of unsymmetrical laminates. This new method is applied to a stacking sequence optimization problem of a maximization of buckling load of cylindrical shell structure. As a result, the method is successfully applied, and the practical optimal stacking sequence is obtained.

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This paper studies the topology optimization for inner ribs of aluminum hollow extruded shell structures by using genetic algorithm. In the optimization, total mass of the structure is minimized under the constraint conditions with respect to maximum deflections of the structure. The deformation of the structure is evaluated numerically by using the finite element analysis developed for two-dimensional elasticity in the present study. In numerical calculations optimal design solutions are obtained for the structures by specifying the allowable maximum deflections of the structure, and the effect of topology of the ribs are studied from the numerical results obtained.

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This paper studies the topology optimization of cantilevered beam-type, extruded aluminum structures subjected to multiple loadings by genetic algorithm. In optimization, maximum deformation of the structure is minimized under a constraint condition, where total number of inner ribs within the structure is kept to be constant, by selecting the locations of the ribs. The deformation of the structure is evaluated numerically by using the finite element analysis developed for two-dimensional elasticity in this study, In numerical calculations optimal design solutions are obtained for the structures subjected to multiple loadings of bending, shearing and stretching.

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For diesel engine combustion, nitrogen oxide (NOx) and soot emissions are major problems. These emissions are mainly controlled by piston geometry. In this work, we conduct multi-objective optimization of piston geometry. Objective functions are related to NOx, soot and CO emissions, as well as indicated thermal efficiency. Theses values are evaluated by GTT code that takes into account the fluid, fuel spray and combustion. Genetic Algorithm using Kriging approximation model is applied as optimization tool. The result shows that optimized shape reduces emissions as well as maintains thermal efficiency.

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In supersonic flights, we face "sonic boom" problem. Sonic boom is a byproduct of shock waves. Busemann's Biplane has been proposed for a significant reduction of shock wave. The interaction of shock wave between the two wings cancels out or reduces the shock wave created by individual wings. In this research, reflection of shock wave is determined by the non-linear theory. Simple extension of Busemann's Biplane for three-dimensional wing causes three-dimensional effect near wing tip. Therefore, winglet is attached to reduce this effect. CFD (Computational Fluid Dynamics) code is used to simulate flow around Busemann's Biplane to investigate the effect of winglet.

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In this paper, Multidisciplinary Design Optimization (MDO) system for practical aircraft design is developed. The MDO system is based on the integration of low and high fidelity computational fluid dynamics (CFD) codes into the NASTRAN based structural/aeroelastic codes. Multi-Objective Genetic Algorithm (MOGA) based on Kriging model is employed as an optimizer to reduce the computational cost. As a result of optimization, several non-dominated solutions, indicating the trade-off among the cruise drag, the structural weight, the drag divergence and the pitching moment, have been generated.

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For the process of product design and development, a technological tool, which quantitatively evaluates the usability of human for the product in advance, has been investigated and developed in the field of design engineering. The computer manikin is expected in order to design welfare products considering the physical performance of the human user. The JACK of a software package was developed as a computer manikin by the Center for Human Modeling and Simulation (HMS) of Pennsylvania University, which is available for the computer simulation of body motion and working based in anatomic structure. This paper introduces the application of JACK to some design of welfare equipments; a wheelchair driving snowy roads, a furniture beside a bed and kitchen system for handicapped. Because the computer manikin can express not all human-performance, knowledge of the human factors engineering and biomechanics is much important for an engineering designer to judge the output of the simulation. When the design is carried out without using the mock-up, thus software is effective as a supporting tool for the evaluation of the usability.

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In this study the method which generates the working plan of a dual manipulator system for robotic sheet metal bending is proposed. In work planning for robotic sheet metal bending, grasping position and reposition timing must be determined and co-operative movement between left- and right-side manipulator is required in order to realize the efficient operation. In the proposed method, the best grasping positions and the reposition timings are determined based on the single manipulator operation and human observation. Computer simulation is carried out based on the proposed method and illustrative examples and results of simulation are given. The effectiveness of this method is discussed.

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The spine consists of vertebrae separated by flexible intervertebral disks. The intervertebral disks act as the flexible spacer between vertebrae and carry significant compressive loads from gravitational and muscle forces. The spine fixation surgery apply to many spinal disorders. The rigid fixation, however, might cause the damage of intervertebral disks. Therefore, it is important to develop the spinal fixation device with the biological intervertebral stiffness. In this study, the flexion, extension, lateral bending and axial rotation stiffness of bovine lumber spine were measured experimentally. And, the finite element based optimization technique was used to design the posterior fixation device with measured stiffness. As a result, optimal design of posterior fixation device was obtained using the proposed method.

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A purpose of this study is to obtain design indices for stiffness of Ankle-foot orthosis (AFO) by measuring ankle joint functions of a hemiplegic patient in order to manufacture and prescribe a more suitable AFO for each of hemiplegic patients. The ankle joint functions of 17 hemiplegic patients and stiffness characteristics of their each AFO are measured and correlations between ankle joint functions and stiffness characteristics of AFO are examined. Then, it is found that planter stiffness of AFO has correlations with passive resistive moment of ankle joints in an ankle-neutral and a knee-extended posture and with passive dorsal stiffness of ankle joint in a knee-flexed posture, respectively. Furthermore, in order to examine meanings of these correlations, analyses for gait of a hemiplegic patient with two different AFOs are performed. Results suggest that these two indices for passive properties of ankle joint are possibly valid for estimating stiffness of AFO suitable for each of hemilplegic patients.

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The paulownia wood is a very special material in wood. Especially, it has excellent flame retardancy. For this reason, it has been often used as drawer for a long time. So in this experiment, such property was verified with a combustion experiment of paulownia wood and a measurement of thermal conductivity. Moreover the structure of the material was analyzed by scanner electron microscope. As a result, in paulownia wood, the cell tissue is very porous like a honeycomb construction, when heated it is easily to carbonized, but hardly ignited. In general, the thermal conductivity of carbonization layer is lower than that of the wood material.

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The suitable airfoil for a micro air vehicle has been studied experimentally. A flapping airfoil is one of solutions for small sized flyers, but the flapping motion similar to insects is not easy to realize because of its complicate mechanism and requirement for light and flexible materials. It is known that insects yield the lift force by a large vortex trapped near the flapping airfoil. Since I noticed that the similar vortex structure is observed near a rotating airfoil around its spanwise axis, the characteristics of the rotating airfoil are studied as an alternative flapping airfoil. The lift force is measured by falling a piece of paper that rotates naturally derived from a well known phenomenon as an auto rotation. Several shapes of airfoil are tested in relation to variety of insect's airfoil. The difference between airfoils of a dragonfly and butterfly is described in this paper.

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Micromechanical characterization of the bony fish scale has been carried out. Composite structure of the scale was analyzed using scanning electron microscope and crystallization of its mineral element was measured by X-ray diffraction. It was found that the scale has two major layers which are the outer layer, consisting of hydroxyapatite and collagen, and inner layer, consisting of only collagen. Elastic modulus and density distributions of the scale were analyzed via distributions of surface wave velocity and acoustic impedance of micro area of the scale measured using a scanning acoustic microscope. The scale of bony fish exhibits Young's modulus of about 7GPa in outer layer and about 5GPa in inner layer.

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In this research, the folding and unfolding manner of small-type petunia flowers was observed by using CCD video camera with timing control. The tensile tests for petals and petal cylinders were carried out. The change of the strain energy absorbed in petal ribs during unfolding of flower was also examined by using the paper model of flowers. It was found that the Young's modulus of petal ribs is much greater than that of petals. Petunia flower deploys quickly for 3〜4 hours following the first slow deployment for 16〜19 hours. And then, it deploys with relatively high speed after the stagnation of 12〜14 hours. The release of strain energy absorbed in the reinforcement axes in a petal cylinder may contribute unfolding of the flower.

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Recently, hip pads have been developed to prevent the femur fracture by falling for aged persons. It is necessary for hip pads that the material and the structure select and design to realize the higher performance of impact absorption. In this work, an experimental system was made to test the impact absorbing properties of hip pad with cellular cushion and commercial hip pad. Using an artificial femur with composite materials that consist of cortical and cancellous region, impact load was applied to greater trochanter of the femoral model. Impact absorbing performance was evaluated by the impulsive force, collision time and impact strain. As a result, significant differences were not showed about absorbing performance in hip pad with cellular cushion except 12mm thickness.

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A numerical method is proposed for deformation analysis of the balloon-expandable stents. An inelastic constitutive model is made from the experimental data of tension-compression tests and is incorporated into the commercial FEM code (MSC Marc/Mentat) to realize accurate prediction. Simulation study is made for the expanding behaviors of the stent made of SUS316L or pure titanium with a balloon mounted inside, and the effects of using different materials are discussed on the mechanical characteristics of the stents.

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In order to simulate the dynamical behavior of red blood cell (RBC) in flowing blood, we developed a spring network model of RBC based on the minimum energy principle. The RBC membrane was divided into small triangular elements consisting of the spring which resists to the stretch, compression and bending of the membrane. The shape of the red blood cell was obtained by solving the motion equation of the mass point assigned at each node in the membrane so that the elastic energy stored in the membrane becomes minimum. The simulation results showed the shape change of RBC passing through a capillary as well as various shapes of RBC obtained by decreasing its volume.

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In the environment such as outer space where we cannot maintain the artifacts, it is the robustness that is important for artifacts. Thus the system, which has the information processing circuit realizing self-maintenance function is desirable. So far some approach is tried to realize self-maintenance function using the qualitative reasoning technique. In this study, we try to apply distributed information processing technique to this qualitative reasoning information processor, by arranging many operating homogeneous units onto an application specific integrated circuit (ASIC). Now we are analyzing the self-maintenance logic by simulation, how the entire system works when frequency of sensors failure change.

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In the present work, the energy recovery and the mechanical recycling of the plastic wastes from the discarded TV sets have been assessed and compared in the context of the life cycle assessment methodology (LCA), in order select the preferred option. The environmental impact of each option has been assessed by calculating abiotic depletion potential (ADP) and global warming potential (GWP), followed by total environmental burden (TEB).

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Modular design methods have been studied for ease of, mainly, manufacturing or assembling. However, modular design methods to reduce environmental loads considering whole product life cycles such as reuse or upgrading have hardly been studied enough. This paper proposes a method for determining modular structure of a product by aggregating various parameters related to a whole product life cycle by using SOM (Self-Organizing Map). This paper also illustrates our prototype system that implements the proposed method and a case study of modular design of a printer. The case study revealed that the proposed method succeeded in modularizing the target product with considering several kinds of parameters including material kinds, lifetimes, and life cycle options..

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In order to realize closed-loop product life cycles, life cycle strategies should be determined appropriately at the early stage of product life cycle design. As an approach for supporting decision of the life cycle strategy, to describe "life cycle scenario" is proposed, which outlines a product life cycle. However, there are no methods to formalize such life cycle scenarios in a computer. In order to solve this problem, this paper proposes a representational framework of life cycle scenarios, which consist of objectives, basic approaches, life cycle options, life cycle flows, and scenes, and a decision support process of life cycle strategy with the life cycle scenario. This paper also illustrates a prototype system developed based on the proposed methodology and a case study of determining a life cycle strategy of a cellular phone.

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We have developed a virtual arm wrestling system for the affect display and interaction of virtual human on the base of human nonverbal behavior and physiological measurement in arm wrestling. In this paper, we examine force display of human arm wrestling under neutral, aiming at including evaluation system into the virtual arm wrestling system for the analysis and understanding of human force display.

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There's likely to problem not to inherit the skills and knowledge about manufacturing and designing. Annotation function in CAD software could embed such informations, however it requires extra operations and the locations depends on the CAD system. So we develop a universal representation method that indicates regions on the 3-D model. This method uses the expression of 3-D locations called as Discrete Direction Expression and extends it. Forthermore we made a user-interface device to indicate 3-D regions on the 3-D model intuitively by the use of mixed reality. Therefore, we suggests a universal representation method for three dimensional partial regions throughout the model lifecycle and suitable interface device.

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Presently, information devices such as cell phones, PDA's (Personal Digital Assistance), and electronic organizers have been changing drastically. Multifunctionality is increasing, sizes have been reduced, and popularity continues to grow. Therefore, usability is becoming important. It has been effective to improve the usability to run the usability testing in the early stages of product development. In usability testing, various prototypes have been made and used. However, in developing prototypes there have always been several problems. For example, a functional prototype is expensive and takes a long time to produce. On the other hand, a design prototype is cheap, but it does not have any functions. In this paper, we propose a method that can create a functional prototype that reduces production time and cost. Furthermore, the functional prototype incorporates input operations and has the ability to record input data. This is done by first creating a quick and cheap model using stereolithography. Then a small camera is inserted to implement user interface functions such as buttons. With this, real time motion images can be processed and recorded.

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We propose a methodology of representing quantitative user diversity as intervals and conducting their calculations using interval arithmetic to evaluate, compare and optimize design ideas considering quantitative user diversity in a general and systematic manner. The proposed methodology and implemented software are applied to two simplified design problems considering quantitative user diversity: a design of a button height on a wall and a design of three dimensional layouts of cellular phone buttons. Through calculation results and a simple user test, we confirmed that the proposed methodology and implemented software can yield adequate information and hints for universal design.

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From the view point of universal design, a product and public sign should use colors which provide color distinguishability to some extent for all users of diverse color vision including color vision deficiencies and yellowing of a crystalline lens by age. At the same time, however, designers need to use colors which make a product or a public sign beautiful and aesthetic. In this research, we propose a systematic method of aiding designers to determine optimal n colors for a product and public sign which meet conditions both on color distinguishability for diverse users and on designer's aesthetic intentions. We confirmed the effectiveness of the proposed method by implementing it as a software, applying 13 colors representing 13 Tokyo subway lines in the route map, and obtaining the adjusted 13 colors of improved distinguishability for all of normal, protanope and deuteranope color vision.

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The present trend of power device packaging indicates that there is a high customer's demand in regarding high reliability. Cooling not only keeps the power device temperature to a specific value, but also affects the solder strain caused by the thermal expansion. Therefore, thermal deign strongly influences the mechanical reliability. In the present paper, the power unit design was completed utilizing the new six sigma approach called DFACE. The main purpose of DFACE is not cost reduction but sales increase, by designing products and business processes meeting customer requirements and generating new value. DFACE (Define, Focus, Analyze, Create, Evaluate) is the project management framework used to achieve these results, using several famous tools and concepts such as PDAC, CVCA, Scorecarding, QFD, Taguchi, AHP, TRIZ... in a systematic approach.

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This presentation shows a multi-objective optimization of a cam shape in a paper feeding mechanism by integrating a multi-objective optimization tool, the modeFRONTIER and a multi-body dynamics simulation tool, the RecurDyn. In order to reduce the feeding motors' load on driving the cam, two objective functions are defined, minimizing the driving torque and leveling the torque fluctuation. As the result, we design a cam shape of which the maximum driving torque was reduced 12% less than that of the initial design and which has stable torque fluctuation.

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Thermal design of electronic equipment in early design stage is the most effective way for reducing the material cost, product size and total developing time. To realize the frontloading thermal design, accurate estimation method of device power dissipation must be required. However, there is no way to measure the power dissipation of inverter due to the variation of device properties, test conditions and so on. We apply an identification method using response surface methodology (RSM) with CFD to estimate the power dissipation of multiple devices on printed wired board. As a verification result, identification error in total power is just 3.4%. This practical approach improves the accuracy of early thermal design quality dramatically.

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It is necessary to consider the flow around a vehicle in the outer parts design such as a sideview mirror and a windshield wiper. However, it takes much calculation time in the flow analysis with the whole vehicle. Furthermore, there is the problem that feedbacks to a design are late for. So we applied a zooming technique in the flow analysis around outer parts. As a result, it was clarified that about 80% calculation time could be reduced. This paper will describe the effectiveness of the flow zooming analysis to the outer parts design.

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In the development of 1BOX-car body structure with many various types, design change of one body type causes too much affection to other body types and causes too much effort to design again. So we tried to use FOA for design process of new car development. And we investigated body stiffness and eigenfrequency of new car body structure by using FOA. In this paper, we report the effectiveness of using FOA in the new car development process.

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In theses latter days, Customer's needs for vehicle performance is diversifying year after year. Under the circumstances, we have to innovate the car new development process due to corresponding to various customer needs. Besides purpose of new process is realization of reasonable price and high quality in short term. In this report, we show the one solution to realize the above- mentioned tasks. Key word is concept study process. Because we recognized concept study phase is very important term in whole development period. But we can't obtain the enough information for CAE analysis in early stage. So We studied new approach for concept study by CAE using simplified model. We introduce the capability of simplified model study for concept study.

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