• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.43-53
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• 1990

Mechanical components and structures are a major part of complex systems and the conseguences of their failure can be extremely costly. The ultimate goal of design engineers is to optimize these mechanical and structural design from the point of view of cost, reliability, weight, volume, maintainability and safety. An essential requirement of design optimization is to develop mathematical models for reliability at design stage. This paper is to minimize the cost of resources subject to the constraint that the reliability of the system must meet a specified level. The lagrange multiplier method is used to optimize the lognormal stress-lognormal strength problem. This optimization problem can be reduced to a search problem in one variable. A numerical example is presented to illustrate the optimization problem.

• Journal of Information Technology Applications and Management
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• v.11 no.4
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• pp.121-132
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• 2004

This paper surveyed 30 system designers and developers who had been participating in a project for five months to examine the usefulness of design artifacts for object-oriented system development. A set of nine requirement and design documents was selected in consideration of the IEEE guidelines. Overall the respondents appeared to agree that the artifacts were useful for system development. On the other hand, the contribution of design artifacts to maintenance was rated lower due to the frequent changes over the iterative process. Of the artifacts, considered more useful were use case specifications, UI design and operation specifications. The respondents were the most reluctant to write test cases. Designers did not like to document more details in the design artifacts than did developers. A future study is required to determine the economics end change management of documentation.

• Knowledge Management Research
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• v.14 no.1
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• pp.1-19
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• 2013

Consumers have collected information and sought advices from other consumer through Internet. They could collect information in virtual space (online) not real world, that is Electronic Word of Mouth (eWOM). This study focused on research the factors on effect in Electronic Word-of-Mouth (eWOM) in the open market which is mediate between individuals and online stores. This is an exploratory study for research on finding factors of effect in eWOM. First of all, 5factors are selected from interview with 31 consumers. Then online surveys are conducted and 5 factors are significantly supported. This study is academically new approach on an exploratory study and it could suggest marketers to strategically manage eWOM.

• Journal of Korean Society for Quality Management
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• v.17 no.2
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• pp.27-35
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• 1989

Software developers often allocate a significant amount of effort to software testing. But for most business-related software system it is natural to expect the continued discovery of defects after the software system is released into field. Such defects are usually very expensive to fix and have the potential to cause great damages to the users. It is important to stop testing the software and release it to the users at the correct time. In this paper, we propose the determination of the optimal number of software test oy minimizing a total expected software cost. A numerical example is used when the criterion is the expected profit. The result indicates that the proposed software release policy based on the number of software test can be a good alternative to the existing policy.

• Journal of Korean Society for Quality Management
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• v.16 no.2
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• pp.82-91
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• 1988

This study is concerned with the development of the economic sampling inspection plan when it is possible to carry out a nondestructive screening inspection for the rejected lots by substitutive characteristics closely related to the original quality characteristic. It is assumed that the probabilities of those errors depend linearly on the fraction defective of the process. The inspection policies considered are as follows: take a random sample of size n from the lot of size N and perform a destructive test on the sample. If the number of the defective items is not greater than a critical number C, accept the lot. Expected cost functions are obtained when the process average can be considered to follow a beta distribution and the way of finding the optimal values of (n, c) is to be explored.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.17-25
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• 2009

세계의 모든 나라가 화석연료를 대체하는 태양광, 풍력 등의 그린에너지 기술개발에 주력하고 있으며, 한편으로는 에너지의 효율제고 및 재생을 위하여 폐기물로부터의 자원순환을 이룩하는 폐기에너지 회수에도 많은 노력을 기울이고 있다. 그 하나의 방편이 버려지는 쓰레기에서 에너지를 회수하는 고형재생연료인 RDF(생활폐기물 고형연료 제품, Refuse Derived Fuel) 생산이다. 우리나라에서는 유일하게 강원도 원주시에서 하루 80톤을 생산하고 있으며 아직은 기술도입 초기단계에 있는 가연성폐기물의 연료화 기술이다. RDF의 특성은 불연성 성분이 제거된 일반 가연물을 분쇄하여 압출성형 가공한 펠릿형상의 고체연료로서의 열적 특성이 우수하나 화재안전 측면에서는 제조 및 취급공정에서의 일반적인 가연물 화재위험성을 가지고 있고, 저장과정에서는 축열발열에 의한 자연발화 위험성이 상존하며, 저장형태, 특히 사이로의 경우 구조특성으로 인하여 화재진압도 쉽지않다. 본 논문에서는 일본의 RDF 화재사례를 중심으로 그 화재 위험 특성과 안전대책을 고찰하고자 한다.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.411-417
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• 2010

캠퍼스 중심의 정규 대학 연구가 급격히 감소될 것으로 예상되면서 대학도 매우 치열한 경쟁 체계를 벗어 날 수 없게 되었다. 이에 다양한 매체를 적용하는 학습방법과 학생의 개념을 다양화하려는 대학들의 노력이 강화됨에 따라 대학 서비스의 핵심인 교육서비스와 행정서비스에 대한 품질 향상은 매우 중요한 과제가 되었다. 본 연구는 대학 서비스의 핵심 중 하나인 행정 서비스를 중심으로 서비스 제공자가 인식한 서비스 품질과 서비스 이용자가 인식한 서비스 품질의 수준이 직무 만족도에 어떠한 영향을 미치는 가를 분석하였다 또한 서비스 제공자가 인식하는 서비스 제공 품질과 서비스 이용자가 인식한 서비스 사용 품질에 관한 두 인식의 차이를 고찰하였다.

• Journal of Korean Society for Quality Management
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• v.8 no.2
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• pp.15-22
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• 1980

This paper deals with the problem of determining a minimum cost sampling inspection plan for a single destructive testing by attribute. The cost for inspection lot is constructed by following three cost factors: (1) cost of inspection, (2) cost of accepted defective, (3) cost of rejected lot Using Hald's Bayesian approach in a single non-destructive testing, procedure's for finding the minimum cost single destructive sampling inspection plan by attribute are given. Assuming the uniform distribution as a prior-distribution and using numerical analysis by computer, a minimum cost single destructive sampling inspection plan by attribute for several lot sizes, unit cost, destructive testing cost, and salvage cost is given.

• Journal of Korean Society for Quality Management
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• v.19 no.2
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• pp.117-124
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• 1991

In this paper, it is assumed that a system is composed of an essential unit and a nonessential unit. During the running of the system, an essential unit is replaced at periodic replacement time T or at nth failure of essential unit whichever occurs first. Nonessential unit is replaced at its failure and at the replacement of essential unit. This paper derive optimal replacement period which minmises the total expected cost for replacement. The unimodality of totoal maintenance cost function is proved under the assumption that hazard rate of each component is continuous and monotone increasing failure rate(IFR). Based on this condition, it is shown that the optimal replacement period is finite and unique.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.1-8
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• 1990

In this paper we present a procedure to determine the quantity of incoming materials when the nonconforming materials appear in the production process. We determined the total loss of materials $D_2$ due to fraction defectives in process and added this $D_2$ to the quantity of incoming materials $Q_0$ considered ingoing-outgoing quality level. The quantity of materials $Q_1$ as a result of this procedure should be an economic purchasing quantity and is a rectifying quantity of the EOQ determined in classical inventory model.