• Structural Engineering and Mechanics
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• v.23 no.4
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• pp.325-337
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• 2006

A hybrid structural design and optimization methodology that combines the strengths of genetic algorithms, local search techniques, and parallel computing is developed to evolve optimal truss systems in this research effort. The primary objective that is met in evolving near-optimal or optimal structural systems using this approach is the capability of satisfying user-defined design criteria while minimizing the computational time required. The application of genetic algorithms to the design and optimization of truss systems supports conceptual design by facilitating the exploration of new design alternatives. In addition, final shape optimization of the evolved designs is supported through the refinement of member sizes using local search techniques for further improvement. The use of the hybrid approach, therefore, enhances the overall process of structural design. Parallel computing is implemented to reduce the total computation time required to obtain near-optimal designs. The support of human-computer interaction during layout optimization and local optimization is also discussed since it assists in evolving optimal truss systems that better satisfy a user's design requirements and design preferences.

• The Journal of Industrial Distribution & Business
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• v.5 no.1
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• pp.17-25
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• 2014

Purpose - Nowadays, the innovative design concept is being implemented in product design. In order to satisfy market trends and the demand for quality, designers should employ customer satisfaction questionnaires and analyze them with various experimental processes. Research design, data, and methodology - These methodologies would help designers have a better understanding of their customers and judge the market size and clustering validity, by diverse product strategies, for dealing with the rapid change prevailing in the market today. Results - By considering the innovative design with regard to telephones as an experimental case, the study investigates and demonstrates how the product can benefit from market-oriented and customized management concepts, when creative design ability is utilized for developing the product. Conclusions - Along with the benefit of having an innovative product value, the product can stimulate progress inthe development of the enterprise management, which has emerged as the main issue in the area of social and economic development in every developed country.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.578-585
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• 1998

A multi-purpose code MAGMA was employed for mold design and process control in producing Al wheel by lowpressure die casting. Three-dimensional solid modeling was followed by mesh generation of casting and molds(top, bottom and side). The simulation of stability of casting cycle time, mold filling simulation with pressure variation from P1 to P2, solidification simulation by solidification time and feeding criteria, and temperature distribution of molds during processes were studied in this research. The thermal stability of molds was attained after 5 cycles when molds were preheated at $400^{\circ}C$. The pressure increase from P1 to P2 for mold filling was evaluated as slightly higher, and 6 seconds were taken for the mold filling. The cycle time was believed to be designed properly judged from the solidification time of casting and open/close time of molds.

• Journal of Navigation and Port Research
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• v.28 no.9
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• pp.775-781
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• 2004

This study aims at helping Chinese container liners keep constant competitiveness in the heated competition Analytic Hierarchy Process (AHP), a mathematics-based, multi-criteria decision analysis methodology is applied in the study to the performance evaluation on the three biggest Chinese container liners: COSCON, CSCL, and Sinolines. Through the final results of AHP model, we completely learn the current situation of Chinese liners, therefore they are able to enhance the competitive advantage from modifying operation strategy and competition strategy in accordance with the shipping market.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1287-1289
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• 2001

This paper presents the logic based islanding protection algorithm for distributed resources(DR) which are interconnected with distribution network. Due to the negative impacts from islanding operations of DR on protection, operation and management of distribution system, it is necessary to effectively detect the islanding operations of DR and disconnect it from distribution network rapidly. Generally, it is difficult to detect islanding operation by monitoring only one system parameter. The proposed islanding protection algorithm utilizes multi-criteria, voltage variation, phase displacement frequency variation, the variation of total harmonic distortion(THD) of current; therefore it effectively detects island operation of DR unit. We also verified the efficiency of the proposed algorithm using the radial distribution network of IEEE 34 bus model.

• Korean Journal of Computational Design and Engineering
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• v.4 no.2
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• pp.100-109
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• 1999

The bearing design includes the steps of selection bering type, selection bearing subtype, and determining the peripheral equipments. In this paper decision making methodologies are compared to propose a stepwise decision methodology to the bearing selection problem. An artificial neural network trained with design cases is used for selecting a bearing type in the first step. Then the subtype of the bearing is selected using the weighting method, high is a kind of multi-criteria decision making method. Finally, the types of peripheral equipments such as lubrication devices, seals and bearing housings are determined using a rule-based expert system.

• Journal of Information Technology Applications and Management
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• v.10 no.2
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• pp.61-71
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• 2003

Ad-hoc networks are characterized by multi-hop wireless links, frequently changing network topology and the need for efficient dynamic routing protocols. In an Ad-hoc network, each host assumes the role of a router and relays packets toward final destinations Because a packet is broadcast to all neighboring nodes, the optimality criteria of wireless network routing is different from that of wired network routing. tn this paper 1 point out the more important cost factor than the number of links in the Ad-hoc network. A class routing protocols called on-demand protocols has recently found attention because of their low routing overhead since it performs a blind flooding to look for a path. In this paper, 1 propose the method which reduces overhead by using the information of neighboring nodes and doing a selective flooding. Simulation results demonstrate better reduction of routing overheads with this scheme.

• Journal of Information Technology Applications and Management
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• v.15 no.1
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• pp.203-224
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• 2008

The purpose of this study is to investigate the evaluation perspectives of IT business value and empirically analyze the differences of evaluation perspectives between ex ante evaluation and post implementation evaluation, and among various information system types. 4 evaluation perspectives which have been used in the previous studies and in the field of industry practices are financial, customer, internal process, and growth, which are based on the BSC model. Data of 98 information systems have been collected from 89 companies including manufacturers, banks, insurances, and stock trading companies. As results of multi-way MANOVA test, 3 out of 8 hypothesis have been accepted statistically. While the order of importance of 4 perspectives in ex ante evaluation is customer, financial, internal process, and growth, the order of post implementation evaluation appears to be much different : that is, internal process, customer, financial, and growth. These findings provide insights for both IT practitioners and researchers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3183-3195
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• 1996

As a method for effective utilization of the limited power and frequency resources in satellite communications, this paper develops software which can assigns the optimal power of input carrier groups inthe multi-level SCPC systems and performs evaluation to a various satellite link environment. Using the developed software, the paper presents performance according to the frequency plan of carrier groups and suggest a frequency play method for performance improvement of satellite link. A various interference and noise caused by satellite link are analyzed for reliable performance evaluation. The performance criteria for evaluation is classified into 2 categories according to the CNR of destination receiver earth station.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.89.2-89
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• 2002

In this paper, we modeled a virtual life (VL) that react to the user's action according to its own behavioral characteristics and grows itself. We established some conditions with which such a VL is designed. Genetic Algorithm is used for the growth process that changes the VL's properties. In this process, the parameter values of the VL's properties are encoded as ore chromosome, and the GA operations change this chromosome. The VL's reaction to the user's action is determined by these properties as well as the general expectation of each reaction. These properties are evaluated through 5 fitness measures so as to deal with multi-objective criteria. Here, we pr...