In this paper, a numerical method for transient dynamic and acoustic analyses of the railway structure with moving loads applied is given. Based on the present method, a computer program to solve the problem has been developed. Numerical examples including the application to a floating ladder track are demonstrated.

View full abstract

A visualization system VIS has been developed to visualize simulation results of a Shinkansen train running at high speed on the railway structure. The VIS is based on an object-oriented approach to create and visualize components of the railway structure including Shinkansen train, the railway structure, and the surrounding environment effectively. Examples including the visualization of a Shinkansen train running on a cable stayed long-spanned concrete bridge in Nagano Shinkansen line are demonstrated.

View full abstract

The new structure optimum design method is presented. It deal with the large-scale structure vibration characteristic problem; divide all structure into the no-change substructure and the design substructure. Make reduction analytical model for the no-change substructure with GDR reduction method; to the design substructure create some basis-vector to adapt to designers needs. Assemble two substructures to the structure, and solve its optimal vibration characteristic result.

View full abstract

In the area of vibration performance analysis using numerical simulation, the mode tracking is a big issue since an order of target mode is varied when numerical model or boundary conditions is changed. In this paper, a new approach is proposed by applying the concept of Mode Assurance Criterion (MAC) to automatic mode tracking and optimization of vibration performance simulation with FEM. An automatic analysis system is integrated by process integration of iSIGHT with an application of Msc. Nastran. A sensitivity study with 81 parameters and 5 levers for each parameter is conducted for a bus model. As a result, the approach proposed here is very effective and total working day is reduced from 20 days by manual to 8 hours by using an automatic system.

View full abstract

Reverse engineering is the solution of engineering to gain digital data from existing objects, and which applied CAD, CAM, CAE, and CAT. And surface reconstruction is the technique for making surfaces from existing objects, and is integral to reverse engineering. When we reconstruct surface, scanned points are gained from existing objects with 3D-coordinate measuring machines, then surface is reconstructed from scanned points. But scanned points sometimes have problems. Surface reconstruction from incomplete points, such as points including noise, is hard. So, we suggest a method of surface reconstruction using implicit function based on Multi-level Partition of Unity Implicits, which is robust to incomplete points.

View full abstract

We proposed Tubes using Origami structure, which has advantages for pedestrian and/or low speed Vehicle collision problem, and examined the crashworthiness of it by finite element method simulation. But these examinations didn't include the Oblique Offset Impact case, although, in real world, many frontal collisions are oblique offset impact. So then, in this report, we examined the crashworthiness of Origami structure in case of Oblique Offset Impact.

View full abstract

It is necessary to model the contact surface of wheel and rail accurately for understanding the behavior of the running train. This paper presents the usefulness to evaluate and examinate of train body behavior on curve rail using explicit FEM code. Authors will show effective model of explicit FE code LS-DYNA for the simulation of train running

View full abstract

This paper describes how economic agents behave under incomplete information in product market with network externality. We have analyzed information cascades, the relation between information and satisfaction, and the effect of individual consumer's decision making to the others using economics theory, simulation and subject experiment.

View full abstract

This paper describes a new approach for work assignment among operators using reinforcement learning. The work assignment is self-organized as the result of local interaction between machines and operators that have a reinforcement learning unit to decide their operational machines. A case study is presented for a semiconductor manufacturing in which it is difficult to find a proper work assignment plan because of large scale of the system and complex process flow. The effectiveness of the proposed method is discussed in the computer simulations results.

View full abstract

In this paper, we proposed the Co-creative Composition in which the musical note agent decides the next position on the musical sheet-like environment, interacting with other agents. The agent decides its action with reinforced learning according to Sensory Consonance Theory. We verified the generated cords, compared with music theory and using psychological experiment. Results showed that the generated chords had similarity to the music theory, and showed that the subjects felt clarity of sound to them.

View full abstract

This paper presents a recycling system model in which economic agents such as producers, consumers and dismantlers make decision in durable goods market. Comparison of theoretical equilibrium and experiments with human subjects shows some characteristics of recycling markets. Especially, we analyze the experimental results with respect to diffusion of recycled products, and reveal relationship between costs and sales.

View full abstract

It is important to unify different knowledge groups, which exist independently, and to extend knowledge gradually in order to obtain creative design solutions that are not obtained only with the existing design knowledge. With the aim of development of "Universal Abduction Studio", which is a system supporting creative design, a knowledge representation and a matching algorithm for creating hypothetic knowledge is proposed in this paper.

View full abstract

Service Engineering is a new engineering idea which aims at increasing service and knowledge contents of added value generated in product life cycle. This paper focuses on service CAD (Computer Aided Design) system, which supports designers to design a service. Firstly, we rearrange the specification of service CAD. Secondly, we propose a definite architecture of our service CAD system and describe the details of each component on the architecture.

View full abstract

Today, environmental issues, such as global warming caused by greenhouse gases, has been emerged as globally emergent issues and governments are expected to take measures to solve these issues. Greening of the automobile tax system, environmental tax, and changes in car tax rate are examples of these measures studied recently. In this study, we propose Co-Creative Institutional Design that creates effective institution resulting from interaction between the institutional designer and the whole system. The emergence of car tax rates considering the reduction of carbon-dioxide emissions by applying Co-Creative Institutional Design to the car tax system is confirmed from the result of computer simulation.

View full abstract

This paper proposes a co-creative decision-making method of artifactual systems to create effective solutions under incomplete conditions. It does so by using bounded rationality as a characteristic of agents. This paper clarifies our concept of "co-creation" and describes difference between co-creative decision-making system and emergent system: emergence multiplex is the most important characteristic of co-creative decision-making systems and the source of their complexity and difficulty. We have classified problems of emergent synthesis into four classes based on level of difficulty. The problems this research deals with is Class-IV: problems with environmental uncertainty, ambiguity of purpose, and agents' bounded rationality. We describe the definition of bounded rational agents and also describe a computer simulation for ascertaining the effectiveness of introducing such agents.

View full abstract

Varying user's sense of value, it is getting more important to deal with users' individual needs and value standard, when designing a product or a service. Such needs or value standard would be not only formed by their own attributes, but also affected by an interaction with other users. To analyze such interaction among users and emergence of needs and value standard, and to build a model of user which could imply such interaction and emergence, we observed a complex network structure which is composed of users. This paper reports an outline and a structure of real network instances, Weblog network and social networking service, applying complex network analysis. Then we propose an information diffusion/spreading model on the complex network, and experiment it by computer simulation on the real users' network.

View full abstract

In this paper, we introduce an on-going experiment of information service based of human feature detection with camera sensors. In the experiment, surveillance cameras in the museum detect customer's height, moving velocity and direction. And his approximate age and needs are estimated. Using the information, pan-tilt projector displays the good information that suits each customer.

View full abstract

An application of the ISM (Interpretive Structural Modeling) approach is proposed to develop the structural model on teaching materials of solid mechanics. It is widely accepted that the common knowledge of solid mechanics in engineering mechanics, strength of materials and so on is the basis in the design engineering. Since the system of knowledge in solid mechanics has long historical background, the teaching method and style of textbooks have shown only slightest changes in recent years. When we consider the trend and capability of recent engineering students, it is increasingly important to reorganize the teaching materials in mechanics to foster the global view of the knowledge. The present report describes the approach to make structural model of the knowledge for efficient understanding by the students.

View full abstract

Set-based design approach is a methodology for conceptual design support and its availability for the application to real design problem, such as the automobile body structure, has been shown. On the other hand, the systematic approach is proposed for a design methodology. In the present study, a computer support system for the education of conceptual design, based on the introduction of the set-based design approach to the systematic approach of design, is proposed.

View full abstract

Lecture of mechanical design is composed of a lot of technical elements, and is complicated. Moreover, the lecture method is different according to student's ability. Therefore, we have developed a teaching material support system for mechanical design. This paper describes the developed teaching material "Reducer" by using the support system. Especially, it is explained as a result that a system was used by a lecture.

View full abstract

An educational approach of design methods at the University of Tokyo is presented in this paper. Design methods taken up in this approach include Semantic differential (SD) method, Quality Functional Deployment (QFD), Design Structure Matrix (DSM), Theory of Inventive Problem Solving (TRIZ), Taguchi Method, Value Engineering (VE), etc. Those methods are well used in the real design work but are not often taught in the design education at a mechanical engineering school of Japan. In order to deepen students understanding of these methods, exercise style is introduced. Students apply those methods to a problem and discuss about the result. They also discuss about characteristics of those methods. It is important to understand that these design methods do not automatically solve a problem but the result may be different depends on an application, a design strategy, a target customer etc. An experience of applying them helps students to understand these characteristics. Advantages of this approach are shown by a result of questionnaire survey.

View full abstract

It is pointed out that market economy observed in the 20^<th> century will no longer be effective and new one to one market will appear in the 21^<st> century, i.e. in an age of wisdom. Products will no longer be evaluated by their final performances alone because diversification will grow so quickly that each product will be evaluated based upon its individual characteristics such as how it is produced. The processes will be an important factor for value in the age of wisdom.

View full abstract

As the diversification of products grow with the increasing diversification of customer's requirements, products will be picking up its personalities, which is characterized by its history of how it is produced, etc. Up until now, product values are determined based upon their performances as a final product, but with this increasing personalization of products, engineers have to consider how the customers really understand the importance of the process in personalizing their products. Engineers should not only visualize the importance of their processes and their roles, but also attempt to provide satisfaction to the customers for doing that. In the 20^<th> century, we have been discussing based upon the current market, but in the 21^<st> century, engineers have to create a new market this way where the customers share the value created by them.

View full abstract

It is pointed out that PBL or Project Based Learning is not only useful for providing students with motivation, problem solving capabilities, strategic thinking, etc, but also for creating a new market. To achieve this goal, team members should be not only from students, but also from customers as well as industrial people. Then how the products are personalized using what kind of technologies could be made visible and the customers and the producers can share the common view toward created values.

View full abstract

Technology development up to now has been focused upon how more advanced technology can be developed. But from the standpoint of creating a new market, new technology development are not necessarily called for. A new product with a new value may be created with combinations of presently available technologies. In this sense, we have to know what is the bottom line level for using the technology rather than to pursue its best level.

View full abstract

We are swamped in innumerable audio & visual contents such as TV, web-site, etc every day. Contents that provide good impressions or good feelings are often good combinations of audio and visual contents. This paper attempted to produce a good combination of audio and visual contents by drawing colored mosaic pictures which match personal impressions or feelings given by music, and evaluated the effects of combination.

View full abstract

Names are not merely "symbols". They represent values and charms of products. Therefore, name impressions were analyzed and the relevance between name impressions and kansei images were investigated.

View full abstract

Electric equipments such as home appliances have become efficient and multifunctional, so that our life is convenient now. On the other hand, the manuals become so complex with the growing complexity and diversification of operations of products that the manuals easy to refer, and to understand are called for. The issues in present manuals are extracted by paying attention to the beginner user, and a manual prototype is developed and its usability is examined.

View full abstract

It is pointed out that our industries have been too much product-based and that more process-oriented industries should be explored. Maslow pointed out that the highest level of human needs is the desire to actualize self, or art. In this sense, the fusion of technology and art should be more advanced. Then, the joy in working or in manufacturing will be reevaluated. Such technologies as remote laboratories may be re-examined from the angle of visualizing manufacturing

View full abstract

The 20th century had been the age of products and the age of mass production and the heavy consumption. Engineers had been focusing their attention to produce better quality products in less time, with less cost and less resources. But such a business model of the 20th century is collapsing because of the change in the environment such as diversification of needs and intensification of an international competition. The 21st century is said the age of wisdom, and the creation of new value is requested. The accumulation of the technology and the skill for many years is indispensable to create new value. But hollowing out of industry and skill technician's aging, and lack of an heir caused a serious problem to the skill tradition. Then it paid attention to the distance learning for help of the skill traditional problem. The distance learning has the characteristics which can provide education for more talents beyond the time and the place. In this paper, it proposed the remote skill tradition system corresponding to the knowledge conversion process of the knowledge management as a method of skill tradition between remote places, and it constructed it.

View full abstract

Internet is increasingly becoming popular and market creation using this technology is getting wide attention. Yet, most of them just replay the role of the traditional Japanese "shosha" and there are very few which provides the user with the joy of participating in the process. Process value is nothing less than product value. Rather sometimes process values are more important than product values. So to explore the possibilities of creating process values by introducing remote laboratory technology, remote laboratory system was developed. The remote student designs a connecting rod, which is then machined by a milling machine in the laboratory at a distance. The instructor in the laboratory installs the connecting rod thus designed on the engine and conducts a trial run, which is viewed by the remote student via internet video. The experiments demonstrate rich possibility of using remote laboratory technology for such a purpose.

View full abstract

This study deals with the fire spreading of general urban districts composed by cell coordinate system. Although there were some works about special plants or structures with large risks until now, it might be investigated about the viewpoint for safety or risk assessment of general urban districts. In this study, we attempt to use Bernoulli sequence as quantity for counting of fire scale and to use the center fire points on cell global coordinate system. In addition, we examine the characteristics of its expansion with fire spreading probability throughout numerical calculation for around cells of disaster points after first fire source by using same conditions.

View full abstract

Structural design of electrical discharge machines (EDM) was investigated to minimize the effect of ambient temperature variances on the thermal deformation. The temperature distribution and the thermal deformation of EDM were simulated with finite element methods (FEM), and these results were seemed to be in good agreement with experimental data The optimization of structural design in EDM was discussed in the use of these FEM simulations

View full abstract

The diversity of the user and use environment are increasing due to the rapid changes in popular taste and in the market which is caused by the internationalization recently. In artifacts design, therefore, we consider the qualitative factors such as user preference and usage. These qualitative factors could be discontinuity, so distribution pattern of fluctuation of functionality could become not normal distribution but nonnormal distribution. In this study, robustness of functionality was assumed as feasibility of which objective characteristic value is in tolerance. And, the way to calculate the robustness based on Monte Carlo method was proposed. We apply our proposal to the railway vehicle seat design and discuss the effectiveness of our proposal.

View full abstract

Conceptual design support techniques are practically mandatory if the most efficient realization of optimal designs is desired. This paper presents a new topology optimization method that considers multiple reliability criteria to obtain, at the conceptual design phase, the most reliable designs of mechanical structures for both static and dynamic problems. This optimization method is constructed based on frame elements. For each frame element, a circular cross-section is assumed as the simplest case, and the normalized cross-section area is treated as design variable. As the multiple reliability criteria, the system reliability is evaluated by modeling the stiffness and eigen-frequency criteria as a series system. Finally, several numerical examples confirm the validity and utility of proposed method, and the importance of considering uncertainties is demonstrated by comparing with deterministic topology optimization.

View full abstract

An efficient and useful robust optimization approach, design for multi-objective six sigma (DFMOSS), has been developed. The DFMOSS couples the ideas of design for six sigma (DFSS) and multi-objective genetic algorithm (MOGA) to solve drawbacks of DFSS. DFMOSS obtains trade-off solutions between optimality and robustness in one optimization. In addition, it does not need careful parameter tuning. Robust optimizations of a test function and welded beam design problem demonstrated that DFMOSS is more effective and more useful than DFSS.

View full abstract

The uncertainties of structural system parameters given by the intervals are studied within the finite element formulation to determine the sharp bounds of the displacement response. Direct approach in which the ordinary real arithmetic is simply replaced with the corresponding interval arithmetic gives extremely overestimated solution of intervals. This problem is called independent problem of interval arithmetic. In order to avoid the overestimation, an approach based on the bracketing of the solution set by subdivided interval boxes is proposed. Validation of this method is tested to the analysis of truss structural systems with uncertainties in nodal coordinates.

View full abstract

This paper discusses a method to determine the optimal direction of the principal moment of inertia in frames element cross-sections for the design of mechanical structures at the conceptual design phase. The direction in each frame element is determined based on the KKT-conditions and the complementary energy concept. This method is implemented as an application in a structural topology optimization that maximizes multiple eigenfrequencies to obtain the most stable designs of mechanical structures for dynamic problems. Finally, several numerical examples confirm the validity and utility of the proposed method, which should be useful for mechanical design engineers at the conceptual design phase.

View full abstract

Typological structural optimization contributes to the optimum design of structures with the minimum weight maintaining a high stiffness. This paper presents a method for achieving topological optimization involving the optimum layout of plural materials for maximizing structural buckling strength. This method is formulated based on both the constraint condition concerning the layout of materials with different strength in the topological optimization and the stability theory of an elastic body with initial stresses. Then, an asteroid-type virtual element is developed based on a substructuring method for the purposes of maintaining a high level of accuracy in a relatively short CPU time. This method is applied to the two-dimensional model of a column, and the validity of this method is confirmed from both the geometrical shape and the material layout regarding the obtained optimization structures. Various optimization shapes and material layouts are illustrated on the column supporting the compressive load in the eccentric axial directions of those.

View full abstract

For a both-ends-clamped beam that is subjected to a concentrated load, it had been shown that the actual most suitable form within the same volume exists only under a certain specific condition that a load was in a limited central region of the span. However, the most suitable form is supposed to exist at a condition except for the above. In this paper, we reconsider the optimization problem of a both-ends-clamped beam that is subjected to a concentrated load under the condition of volume constancy as minimization of functions related to displacement and as uniformity of the strain energy density by GA.

View full abstract

This paper proposes an innovative two-step approach to the design of practical and sophisticated compliant mechanisms. The approach consists of two optimization methods; topology and shape optimizations and a scheme to implement designer input of ideas. In the first step, a designer explores the most fruitful design concepts by combining several compliant mechanisms generated by the topology optimization with additional mechanisms based on his or her ideas. In the second step, the shape optimization procedure yields a detailed optimal shape based on the design concept.

View full abstract

A new optimization method for the design of axial turbine stages is described, which can search for the global optimum solution and realize the robust design. The feature of the new method include creating orthogonal arrays, changing the level values of design factors, and evaluating standard deviation of the objective function for every search step. As a result of applying the method to the optimum design of turbine stages, it is shown that the method can search the global optimum solution and the tolerances of design factors greatly affect the robustness of turbine efficiency.

View full abstract

This paper has tried to apply structural optimization techniques to develop a new aluminum beverage can end. Geometrical parameters of the end shell are selected as design variables. The analysis points in the design space are assigned using an orthogonal array in the design-of-experiment technique. Finite element analysis code is used to simulate the deforming behavior and to calculate buckling strength and central panel displacement of the end shell under internal pressure. On the basis of the numerical analysis results, the response surface of the buckling strength and panel growth are approximated in terms of the design variables. Using Design Optimization Tools (DOT), the weight of the end shell is minimized subject to constraints of the buckling strength, panel growth suppression and other design requirements. A numerical example has been shown on the end shell in a new shape.

View full abstract

The structure of a railway vehicle was designed from viewpoints of weight and margin of safety by using the new optimum structural design method that is using HyperSizer and NASTRAN. By this method, the form and material of structure of railway vehicle were investigated widely and the efficiency of a design process was increased.

View full abstract

In this paper consider the problem of lens distortion calibration of semiconductor lithography equipment. The target of calibration is to minimize the maximum absolute value of the distortion. Formerly, approximate solution used to be calculated by the least-squares method. Recently, iterating the least-squares method with weight was proposed. However, calculation time may often become long and a better solution was desired. In this paper we propose application of "the maximum absolute value minimization by linear programming." With this method, we have been successful in decreasing 15 data of experimental distortion about 40% smaller than the calibration with least-squares method. In addition, this solution is assured to be the exact optimal solution, and the calculation time is very small.

View full abstract

In this paper, we present a method to create draw-beads for improving the strength of sheet metal structures. We define a mechanically natural creation law such that local curvatures are created in proportion to the amount of local stresses in the perpendicular direction of the principal stress direction for resisting distributed bending moments. The local curvature is created by self-equilibrium bending moment. Owing to the law, the draw-beads are created without any artificial operations such as basis vectors. The thickness is assumed to be constant and the volume is constrained to a specified value. By repeating the stress analysis and the bead creation analysis alternately, the maximum stress is reduced, while creating the draw-beads. Orthogonal material property is defined only in the bead creation analysis. A threshold value is introduced to avoid a meaningless disturbance of the shape, and its effect is investigated. The validity of this numerical method to create the draw-beads for improving the strength of sheet metal structures is verified through some examples.

View full abstract

It is said that branch systems in nature is optimum structures for many purposes. If reproduction method of branch system in nature is developed, it is expected the control law of branch system in nature will be found out. In this paper, reproduction algorithm of root branch system in nature is developed and optimality of generated branch system morphology is discussed. Influence of the parameters used in reproduction algorithm of branch system in nature is studied numerically, which can avoid overlapping each branches.

View full abstract