• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.11
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• pp.56-64
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• 1992

The sum-of-product type MVL (Multiple-valued logic) functions can be directly transformed into the exclusive-sum-of-literal-product(ESOLP) type MVL functions with a substitution of the OR operator with the exclusive-OR(XOR) operator. This paper presents an algorithm that can reduce the number of minterms for the purpose of minimizing the hardware size and the complexity of the circuit in the realization of ESOLP-type MVL functions. In Boolean algebra, the joinable true minterms can form the cube, and if some cubes form a cube-chain with adjacent cubes by the insertion of false cubes(or, false minterms), then the created cube-chain can become a large cube which includes previous cubes. As a result of the cube grouping, the number of minterms can be reduced artificially. Since ESOLP-type MVL functions take the MIN/XOR structure, a XOR circuit and a four-valued MIN/XOR dynamic-CMOS PLA circuit is designed for the realization of the minimized functions, and PSPICE simulation results have been also presented for the validation of the proposed algorithm.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.4
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• pp.754-763
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• 2001

The purpose of this study was to examine: 1) the differences in the automation level by company characteristics(i.e., product category, product type, firm size); 2) the effects of company context(i.e., environmental uncertainty, task uncertainty) on the automation level; and 3) the effect of the automation level on manufacturing performance(i.e., quality, flexibility, time, cost). Data were collected from a mail survey. Four hundred eighty two questionaries were mailed to apparel manufacturers nationwide, and 60 responses were analyzed. The results revealed that: 1) mens and womens wear manufacturers and large manufacturers(i.e., the number of employees, sales volume) showed higher automation level; 2) environmental complexity positively affected the automation level; and 3) the automation level had a positive effect only on quality performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.139-155
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• 2006

The facility location problem of this paper is distinguished from the maximal covering location problem and the flxed-charge facility location problem. We propose the maximal profiting location problem (MPLP) that is the facility location problem maximizing profit with multi-product. We apply to the simulated annealing algorithm, the stochastic evolution algorithm and the accelerated simulated annealing algorithm to solve this problem. Through a scale-down and extension experiment, the MPLP was validated and all the three algorithm enable the near optimal solution to produce. As the computational complexity is increased, it is shown that the simulated annealing algorithm' is able to find the best solution than the other two algorithms in a relatively short computational time.

• IE interfaces
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• v.20 no.3
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• pp.395-406
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• 2007

In the telecommunication industry, estimation of the cost of network facilities is very important since depreciation cost of the facilities accounts for a large portion of the product cost. Moreover, cost estimation in the industry becomes more difficult because of increasing indirect cost upon digital convergence, expanding multi-purpose facilities, complexity of service product, etc. Nevertheless, not much seem to have been done in improving estimation methodology of the cost of network facilities. As a result, the quality of cost information on network facilities has deteriorated, and now even decision-makers in the industry dismiss the information. Recently, two major telecommunication companies adopted a new network cost estimation method to deal with the issue. In this paper, we study the concept of new cost estimation method and the procedure to develop and apply it. We also suggest the method to carry out the cost allocation using Matlab which is more efficient and time-saving than other commercial cost calculation packages.

• Korean Management Science Review
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• v.17 no.3
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• pp.73-95
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• 2000

In Korea, the distribution channel for agricultural products is notorious for its complexity and ineffectiveness. In this sense, the Agricultural Cooperative has tried to clarify the distribution channel and reduce its length. However, there still exist much room for improvements. The Internet shopping mall specific for agricultural product, therefore, is drawing much attention because it can reduce the length of distribution channel drastically and improve effectiveness from the distribution perspective. To test the validity of such Internet-driven shopping mall, we gathered questionnaire data from the Internet based Hannaro Shopping Mall which is run directly by the Agricultural Cooperative. We performed experiments respectively for the two groups of operating personnel and consumers. Experimental results showed that several important factors can be identified which are significant statistically and deemed to have meaningful relationship with performance variables. Our results also showed that the Internet shopping mall has a great potential for improving the effectiveness of the distribution channel of the agricultural products.

• IE interfaces
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• v.25 no.4
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• pp.376-381
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• 2012

As the number, complexity and interaction of electrical, electronic and programmable electronic (E/E/PE) systems increase, a growing emphasis has been placed on the concept of functional safety during product development. IEC 61508 provides guidelines and standardized procedures in the development of reliable and dependable E/E/PE systems to assure functional safety. Determining risk classes (i.e., safety integrity levels, SILs) associated to a specific E/E/PE item may be recognized as one of the most crucial activities in the product development per IEC 61508 since SILs are used to specify necessary safety requirements for achieving an acceptable residual risk. This article presents a case study on the assessment of SILs applying failure modes, effects and diagnostic analysis (FMEDA) from which failure rates may be derived for each important failure category by combining a standard FMEA with online diagnostic techniques.

• Journal of Korea Society of Industrial Information Systems
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• v.3 no.1
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• pp.67-77
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• 1998

Reliability growth testing used to evaluate reliability in the automobile industry have not always been able to correctly address reliability concerns with increased confidence. The demand to confirm to all product performance requirements under various operating environments has added to the complexity of accurately assessin theproduct's reliability in the required development time. In addition, it is often desired to determine the relationship of a product's reliability to cost, development time, design, manufacturability and assembly. This paper presents the methods for reliability growth modeling to evaluate and interpret reliability concerns to support the reliability analysis of automobile assemblies and systems. This reliability growth modeling process is a mechanism to help "build in" reliability during early phases in the vehicle devleopment stage.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.526-532
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• 2005

Representation of product data for exchanging and sharing a plant information was established the International Standard by ISO 10303 (STEP) and ISO 15926, but is not used widely in industrial circles by massiveness of standard and complexity of plant itself Specially, they are embodied to STEP data file(ISO 10303 Parts 21), but STEP file is uncomfortable that a person recognizes, and needs specification creation tool. In this paper, we made the integration schema for control valve through related standards, Also, we suggest the practical use framework for electronic commerce to utilize the XML schema that can represents integrate schema of control valve to use XML that is becoming the latest issue.

• Korean Management Science Review
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• v.10 no.1
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• pp.193-205
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• 1993

This paper presents a mathematical model for a class of vertical integration decisions. The problem structure of interest consists of raw material vendors, components suppliers, components processing plants, final product (assembly) plants and external components buyers. Economic feasibility of operating components plants instead of keeping outside suppliers is our major concern. The model also determines assignment of product lines and production volumes to each open plant considering the cost impacts of economies of scale and plant complexity. The problem formulation leads to a concave, mixed integer mathematical program. Given the state of the art of nonlinear programming techniques, it is often not possible to find global optima for reasonably sized such problems. We developed an optimization solution algorithm within the framework of Benders decomposition for the case of a piecewise linear concave cost function. It is shown that our algorithm generates optimal solutions efficiently.

• KSCI Review
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• v.2 no.1
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• pp.109-120
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• 1995

The purposes of this paper are to construct the author tools that have influence on system package in EXSYS professional, to design the objects and the roles of development members on the phases of development life cycle, to study on the increase of efficiency in the main phases that have much influence on the efficiency of authoring tool development. The major factors which affect authoring tool are as follow : the size of the product, the individual capability of project personnel, the project period, the complexity of the product, the required level of reliability and the level of technologies utilized.