• 한국철도학회논문집
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• 제14권4호
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• pp.376-382
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• 2011

오늘날 웹사이트의 서비스 품질은 기업의 효율적인 업무수행과 고객의 소비행동에 중요한 영향을 미치는 핵심요인으로 인식되고 있다. 본 연구는 현재 한국철도공사에 의해 제공되고 있는 철도물류정보서비스에 대한 서비스품질(신뢰성, 유용성, 외형성, 편리성)과 해당 정보서비스를 이용하는 화주의 만족도와의 관계를 검증하기 위한 연구이다. 회귀분석 결과, 신뢰성과 유용성은 화주의 만족도에는 유의한 정(+)의 효과를 미치는 것으로 검증되었으나, 편리성과 외형성은 영향을 미치지 않는 것으로 나타났다. 본 연구의 목적은 화주의 만족도를 향상시키기 위한 철도물류정보서비스의 제공 전략을 제시하는데 있다.

• 한국생산제조학회지
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• 제24권5호
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• pp.521-529
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• 2015

Owing to a reliance on imported products from Europe and Japan, the use of logistics equipment with poor energy efficiency coupled with high maintenance costs can lead to high operating costs for some domestic logistic centers. To lower their operating costs, the logistic centers use motorized roller conveyors. In order to commercialize this process, it is necessary to establish the test criteria and assess the reliability of the process. Currently, there exists no standard verification method to test the reliability of motorized roller conveyors. In this study, we propose reliability assessment criteria for a: i) reliability test, ii) environmental test, iii) safety test, and iv) lifetime test.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.256-257
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• 2015

시장의 세계화와 정보통신의 발전에 의해, 운송망의 길이가 길어지고, 복잡화되었다. 이 때문에 운송신뢰성에 대한 연구의 필요성이 높아졌다. 본 연구에서는 트럭운송 시에 발생할 수 있는 예상치 못한 위험 사건의 결함나무분석(FTA)를 통해 정의하며, 각 위험사건간의 관계를 표현하여 실패율을 사례를 이용하여 구한다. 이를 통해 중간 위험사건 4가지에 대한 페트리네트를 통해, 인과관계를 고려한 순서와 시간에 따른 위험사건의 발생을 고려한 신뢰성을 신뢰도 함수를 이용하여 도출한다. 물류 운송시스템에 대한 신뢰성을 공학적인 방법론을 사용하여 수리적으로 도출한다는 점에서 연구의 의의가 있다.

• Journal of Korea Trade
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• 제27권5호
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• pp.63-90
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• 2023

Purpose - This study aims to identify the relationship between logistics companies' Logistics 4.0 technology adoption with logistics innovation capability and logistics performance, and analyze the mediating effect of logistics innovation capability and the mediated moderation effect of firm size through logistics innovation capability. Design/methodology - Research models and hypotheses were established based on prior research related to Industry 4.0, Logistics 4.0, logistics technology, logistics performance, and firm size. The survey was conducted on the employees of logistics companies, and exploratory factor analysis, reliability analysis, confirmatory factor analysis, discriminant validity analysis, structural equation model analysis, mediation effect, moderation effect, and the mediated moderation effect analysis were performed. Findings - The adoption of Logistics 4.0 technology was found to significantly affect logistics innovation capability and logistics performance. Logistics innovation capability was found to significantly affect logistics performance. Moreover, logistics innovation capability was found to have a significant mediation effect on the relationship between Logistics 4.0 technology adoption and logistics performance. The moderation effect based on firm size was found to have a partial effect on logistics innovation capability and logistics performance, but the mediated moderation effect was not significant. Originality/value - This study is meaningful in that it empirically analyzed the relationship of Logistics 4.0 technology adoption with logistics innovation capability and logistics performance, the mediating effect of logistics innovation capability, the moderation effect of firm size, and the mediated moderation effect of firm size, which were not addressed in previous studies.

• 산업공학
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• 제25권2호
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• pp.153-162
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• 2012

The reliability is defined as a probability that a system will operate properly for a specified period of time under the design operating conditions without failure and it has been considered as one of the major design parameters in the field of industries. Reliability-Redundancy Optimization Problem(RROP) involves selec tion of components with multiple choices and redundancy levels for maximizing system reliability with constraints such as cost, weight, etc. However, in practice both active and cold standby redundancies may be used within a particular system design. Therefore, a redundancy strategy(active, cold standby) for each subsystem in order to maximize system reliability is considered in this study. Due to the nature of RROP, i.e. NP-hard problem, A Parallel Particle Swarm Optimization(PPSO) algorithm is proposed to solve the mathematical programming model and it gives consistently better quality solutions than existing studies for benchmark problems.

• Industrial Engineering and Management Systems
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• 제7권1호
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• pp.51-56
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• 2008

With growing demand for zero defects, predicting reliability of software systems is gaining importance. Software reliability models are used to estimate the reliability or the number of latent defects in a software product. Most reliability models to estimate the reliability of software in the literature are based on the development lifecycle stages. However, in the maintenance phase, the software needs to be corrected for errors and to be enhanced for the requests from users. These decrease the reliability of software. Software Reliability Growth Models (SRGMs) have been applied successfully to model software reliability in development phase. The software reliability in maintenance phase exhibits many types of systematic or irregular behaviors. These may include cyclic behavior as well as long-term evolutionary trends. The cyclic behavior may involve multiple periodicities and may be asymmetric in nature. In this paper, SGRM has been adapted to develop a reliability prediction model for the software in maintenance phase. The model is established using maintenance data from a commercial shop floor control system. The model is accepted to be used for resource planning and assuring the quality of the maintenance work to the user.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.101-103
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• 2021

전 세계적으로 수출입 화물이 급격하게 늘어나면서 기업들은 창고의 효율성 증가와 창고 인력 감소로 인해 무인 자동화창고에 대한 관심과 연구개발이 증가하고 있다. 소규모 창고에서는 재고의 흐름을 유동적으로 할 수 있는 셔틀랙 기반의 레이아웃이 빈번하게 존재한다. 그러나 셔틀랙 기반의 물류센터는 비상상황(고장, 정전 등)에서 셔틀이 작동하지 않아 물류센터 효율성과 재고관리에 심각한 영향을 미치고 있다. 이에 셔틀랙 기반의 물류센터에서 다양한 셔틀의 통로와 RTV의 통로를 레이아웃별로 분류하고 특성과 유형을 분석하여 각 레이아웃별로 신뢰성을 도출하였다. 통로의 개수에 따라 적재율도 다르게 도출되어 각 레이아웃별로 신뢰성과 적재율을 비교 분석하였다.

• 무역학회지
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• 제45권1호
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• pp.259-277
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• 2020

The purpose of this study is to analyze the relationship between logistics safety climate, logistics safety behavior, and logistics safety performance and the mediating effects of safety knowledge and safety motivation, and to suggest its strategic implications for the improvement of the logistics safety performance. Based on previous researches related to logistics safety, safety climate, safety knowledge, safety motivation, safety behavior and safety performance, research models and hypotheses were set up and questionnaires were conducted. For the hypothesis test, reliability analysis and validity analysis, confirmatory factor analysis, structural equation model analysis, and bootstrapping were applied. As a result of the empirical analysis, the logistics safety climate had a significant positive effect on logistics safety knowledge, logistics safety motivation, and logistics safety behavior, whereas logistics safety knowledge and logistics safety motivation had a meaningful positive effect on logistics safety behavior. Further, logistics safety behavior was found to have a significant positive effect on logistics safety performance. Safety behavior had a significant mediating effect, but safety knowledge and safety motivation did not. However, logistics safety climate, logistics safety knowledge, and logistics safety motivation did not have a significant effect on logistics safety performance.

• 대한산업공학회지
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• 제37권4호
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• pp.390-399
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• 2011

Generally the life-cycle cost of complex systems composed of several sub systems or equipments such as train, aircraft weapon systems is spent much more during operation and maintenance phase than development phase. The maintenance cost for maintaining the availability and extending the life span of systems comprise a large proportion of systems operation cost. The cycle of preventive maintenance affects operation and maintenance cost a lot. In this study we introduce a way minimizing life-cycle cost of systems by calculating more reliable preventive maintenance period than the results of previous study using systems reliability data considered the reliability and failure effect ratio of sub-systems or components. We can solve the preventive maintenance period problem known as NP-Hard as quick as possible by using modified genetic algorithm than using other models introduced in previous study.

• 대한산업공학회지
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• 제40권1호
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• pp.118-127
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• 2014

The configuration such as series, parallel and k-out-of-n of a repairable system directly affects its reliability. The maintenance strategy can also affect the overall performance of the system. The objective of this work is to investigate the possible trade-off between the configuration of a repairable k-out-of-n system and its maintenance strategy. The redundancy is considered to be the design decision variables, whereas the preventive maintenance period is considered to be the maintenance decision variables. The optimization model is used to minimize the overall life cycle cost associated with the system, considering constraint on reliability. Finally, genetic algorithm is used to find the optimal values for the decision variables. The result is compared with optimal values for considering redundancy and maintenance respectively.