• Structural Engineering and Mechanics
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• v.3 no.4
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• pp.373-382
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• 1995

The weighting strategy has received a great attention and has been widely applied to multicriterion optimization. This gaper examines a global criterion method (GCM) with the weighting objectives strategy in fuzzy structural engineering problems. Fuzziness of those problems are in their design goals, constraints and variables. Most of the constraints are originated from analysis of engineering mechanics. The GCM is verified to be equivalent to fuzzy goal programming via a truss design. Continued and mixed discrete variable spaces are presented and examined using a fuzzy global criterion method (FGCM). In the design process a weighting parameter with fuzzy information is introduced into the design and decision making. We use a uniform machine-tool spindle as an illustrative example in continuous design space. Fuzzy multicriterion optimization in mixed design space is illustrated by the design of mechanical spring stacks. Results show that weighting strategy in FGCM can generate both the best compromise solution and a set of Pareto solutions in fuzzy environment. Weighting technique with fuzziness provides a more relaxed design domain, which increases the satisfying degree of a compromise solution or improves the final design.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.3 s.153
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• pp.332-339
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• 2007

Integration of engineering information through the IT (Information Technology) is very important key during the collaboration design process. How can we realize the data efficiently in real-time at the early design stage? How can we manage to integrate the separate information made by each designer or department effectively in real time? IT global trend is the unique way of handling these complicated problems from the information inundation. This paper suggests the design process management system deduced from the analytical results considering BPM (Business Process Management) solution workflow. Workflow based design process management system can help user share and integrate the needed information at the right time through Internet. It is found that the proposed tool works well for a beam design case, and this framework can be thus further expanded for an engineering design environment smoothly.

• Transactions of Materials Processing
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• v.23 no.4
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• pp.206-210
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• 2014

The metal lead frame, a semiconductor component, has product tolerances in micro units as compared to products made with a larger size mold. Therefore, small deflections of the mold and of the press as well as the press molding process itself have a strong influence on accuracy of the product. Hence, it is necessary for the process design to consider the structural response of the mold and the press during deformation. In the current study, the mold deflection and pressure on the punch is examined using the finite element modeling (FEM) program ABAQUS. The results from the simulation were verified with the dynamic deformation measurement equipment using digital image correlation (DIC).

• Journal of Mechanical Science and Technology
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• v.18 no.7
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• pp.1121-1130
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• 2004

The Genetic Algorithm (GA), an optimization technique based on the theory of natural selection, has proven to be a relatively robust means of searching for global optimum. It converges to the global optimum point without auxiliary information such as differentiation of function. In the case of a complex problem, the GA involves a large population number and requires a lot of computing time. To improve the process, this research used parallel processing with several personal computers. Parallel process technique is classified into two methods according to subpopulation's size and number. One is the fine-grained method (FGM), and the other is the coarse-grained method (CGM). This study selected the CGM as a parallel process technique because the load is equally divided among several computers. The given design domain should be reduced according to the degree of feasibility, because mechanical system problems have constraints. The reduced domain is used as an initial design domain. It is consistent with the feasible domain and the infeasible domain around feasible domain boundary. This parallel process used the Message Passing Interface library.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.662-674
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• 2017

This paper describes the multidisciplinary design optimization (MDO) process of a tailless unmanned combat aerial vehicle (UCAV) using global variable fidelity aerodynamic analysis. The developed tailless UAV design framework combines multiple disciplines that are based on low-fidelity and empirical analysis methods. An automated high-fidelity aerodynamic analysis is efficiently integrated into the MDO framework. Global variable fidelity modeling algorithm manages the use of the high-fidelity analysis to enhance the overall accuracy of the MDO by providing the initial sampling of the design space with iterative refinement of the approximation model in the neighborhood of the optimum solution. A design formulation was established considering a specific aerodynamic, stability and control design features of a tailless aircraft configuration with a UCAV specific mission profile. Design optimization problems with low-fidelity and variable fidelity analyses were successfully solved. The objective function improvement is 14.5% and 15.9% with low and variable fidelity optimization respectively. Results also indicate that low-fidelity analysis overestimates the value of lift-to-drag ratio by 3-5%, while the variable fidelity results are equal to the high-fidelity analysis results by algorithm definition.

• Korean Journal of Computational Design and Engineering
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• v.17 no.5
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• pp.375-386
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• 2012

Most engineering design problems require analyses or simulations to evaluate objective functions. However, a single simulation can take many hours or even days to finish for many real world problems. As a result, design optimization becomes impossible since they require hundreds or thousands of simulation evaluations. The surrogate-based optimization (SBO) strategy became a remedy for such computationally expensive analyses and simulations. A surrogate-based optimization strategy has been developed in this study in order to improve global optimization performance. The strategy is a heuristic algorithm and it exploits not only multiple surrogates, but also multiple optimizers. Multiple optimizations of multiple surrogate models yield multiple candidate design points of optima. During the sequential sampling process, the algorithm ranks candidate design points, selects the points as many as specified, and builds the improved surrogate model. Various mathematical functions with different numbers of design variables are chosen to compare the proposed method with the other most recent algorithm, MSEGO. The proposed method shows superior performance to the other method.

• Architectural research
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• v.7 no.2
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• pp.23-33
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• 2005

The use of computers in architectural professions has grown with the power of easy data management, increased sophistication of standalone applications, inexpensive hardware, improved speed of processing, use of standard library and tools for communication and collaboration. Recently, there has been a growing interest in distributed CAAD (Computer-Aided Architectural Design) integration due to the needs of direct collaboration among project participants in different locations, and Internet is becoming the optimal tool for collaboration among participants in architectural design and construction projects. The aim of this research is to provide a new paradigm for a CAAD system by combining research on integrated CAAD applications with recent collaboration technologies. To accomplish this research objective, interactive three-dimensional (3D) design tools and applications running on the Web have been developed for an Internet-based distributed CAAD application system, specifically designed to meet the requirements of the architectural design process. To this end, two different scopes of implementation are evaluated: first, global architecture and the functionality of a distributed CAAD system; and, second, the association of an architectural application to the system.

• Journal of Engineering Education Research
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• v.21 no.6
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• pp.35-43
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• 2018

In many universities, the Capstone Design course aims to educate creativity, teamwork and leadership, and ultimately aims to cultivate practitioners with practical ability required in the industry. Since the introduction of capstone design as a regular course, it has spread not only to engineering but also to the humanities and social sciences. A typical capstone design is usually carried out within a limited range of schedules and budgets within the scope of a major and a subject. In the case of a special-purpose capstone design, it is necessary to find out excellent items aiming at start-up and commercialization at an early stage, It contributes to the achievement of international convention participation, start-up and commercialization. The teaching styles of capstone design such as multidisciplinary capstone design, fusion capstone design, and global capstone design are developed and operated in various ways. Depending on each type, objectives, curriculum, scope of participation, operation method, performance and so on. In the case of capstone design, it is contributing to increase the achievements such as participation in international conventions, establishment of business and commercialization by early detection of excellent items aiming at start-up and commercialization, development and establishment of support process. Technological and Humanities Convergence Capstone Design Moel is named as the process of designing a four-level idea called "Idea Factory-based Technology-Humannities Fusion Capstone Design Process", and it is used to generate ideas, elaborate ideas, advanced ideas, and commercialization.

• Journal of Korea Port Economic Association
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• v.29 no.4
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• pp.201-222
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• 2013

The purpose of the present study is to analyze how and to what degree multinational companies organize and operate their supply chains in accordance with the strategic resource of knowledge in their multinational management, and what kind of influence knowledge oriented global supply chain management has on the management performance of multinational corporations. For this purpose, the current research proposed a measurement model to provide specific shape to the concept of knowledge oriented global supply chain management by adopting the knowledge creation process proposed by Nonaka (1994), and conducted an empirical analysis of what kind of impact the knowledge management system and the knowledge creation process of companies have on the performance of their global supply chain management. The result of the empirical analysis of 113 multinational companies verified the validity and reliability of the measurement model proposed in this study. In addition, the comparative study of the sampled companies by grouping them according to the level of knowledge orientation in global supply chain management indicated that the enterprises that effectively manage the knowledge created within the global supply chain presented overall superiority on the performance of global supply chain management.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.832-835
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• 2003

The objective of this study is to investigate the possibility of chemical process synthesis purely based on mathematical programming when given an objective, feed conditions, product specifications, and model equations for available process units. A method based on a state space approach is proposed, and applied to an example problem with a reactor, a heat exchanger, and a separator. The results indicate that a computer can automatically synthesize an optimal process without any heuristics or expertise in process design provided that global optimization techniques are improved to be suitable for large problems.