• 한국산학기술학회논문지
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• 제16권5호
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• pp.3525-3534
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• 2015

하수시설 자산관리체계 구축에서 가장 중요한 요건중의 하나는 하수 서비스 공급을 위한 관리 수준을 결정하는 것이다. 하수관련 시설이 건설되고 나면 운영단계에서 발생하는 개 대체 항목의 많은 부분들이 민원이나 사용자의 요구에 의해 이루어지게 된다. 이러한 서비스 수준을 관리하기 위해서 어느 지역에 어떤 민원이 주로 발생하고 있으며 어떤 부분을 개선시킬 것인지를 찾아 서비스 관리 목표를 설정하는 것이다. 본 연구에서는 이러한 점을 반영하여 국내 자산관리 수행이 진행되고 있는 S지역의 하수 민원대장을 분석하였으며 이를 토대로 지역 특성별로 민원발생 대상 시설과 민원 발생 유형을 분석하여 서비스 제공 관리기준을 개발하였다. 이를 선진 하수시설 자산관리 밴치마킹 대상지역과 비교하여 S지역만의 Best Practice 구현을 위한 기준을 설정하였다.

• 한국건축시공학회지
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• 제10권2호
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• pp.81-88
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• 2010

우리나라는 공동주택 관리에 관한 규칙에 의거하여 하자보수 보증금을 예치하고 이를 기반으로 공동주택 입주자들의 하자보수 요구에 대응하고 있다. 현재 민간주택사업자들의 경우 막대한 시간과 비용을 들여 구축한 자사의 브랜드 이미지 고수를 위하여 자신들이 건설한 주택의 품질확보 및 A/S에 큰 노력을 기울이고 있다. 그러나 현재 하자보수에 투입되는 비용중에는 순수한 하자보수에 투입되는 비용이외에 단지내 미화 등 입주민들의 비합리적인 요구사항에 투입되는 비용 또한 있는 것이 사실이다. 따라서 본 연구에서는 39개단 단지를 대상으로 하자보수에 투입되었던 실적자료를 근거로 실제로 하자보수에 투입된 하자성비용과 단지내 미화 등 하자보수와 연관성이 적은 기타비용인 민원성 비용의 사용실태를 분석하였다. 분석결과 하자성비용과 민원성 비용이 거의 비슷한 비율을 차지하고 있으며, 민원성비용이 오히려 높은 결과를 보였다. 이러한 분석결과는 입주자들의 비합리적인 요구 및 주택사업자들의 근시안적인 대처에 기안하는 것으로 사료된다.

• 정보교육학회논문지
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• 제7권1호
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• pp.48-56
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• 2003

본 연구에서는 교사가 교육용 홈페이지를 손쉽게 유지 보수할 수 있도록 템플릿 시스템을 구현하였다. 이것은 회원과 학교 정보를 관리하는 정보 관리 시스템, 이러한 기본 정보과 ASP로 이루어진 템플릿 파일을 이용하여 인터페이스를 구성하는 템플릿 관리 시스템, 사용자에게 보여질 메뉴를 손쉽게 추가하고 수정할 수 있는 메뉴 관리 시스템으로 구성되어진다. 시스템을 운영해본 결과 학교 홈페이지의 활용도를 크게 향상시켰으며, 교사와 학생의 ICT 활용 능력 향상과 교육 정보화에 기여할 것으로 기대된다.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.276-290
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• 2020

연구목적: 국내 항만시설의 건설역사는 100년 이상 되었으며 최근 까지 현대적 시설이 지속적으로 건설되어 확장되고 있다. 그러나, 해양환경의 변화 및 물동량의 증가 등으로 초기 건설당시의 요구 성능조건을 유지하기는 쉽지 않다. 특히, 사용년수가 오래된 항만구조물의 경우, 선박의 대형화와 사용빈도 증가, 자연재해의 규모 증가등으로 안전성능과 기능관리가 매우 중요해져 가고 있다. 연구방법: 이에 본 연구는 항만시설의 구조형식별 상태변화를 조사하고 이를 기반으로 성능개선 및 수명연장활동에 기여하는 보수보강활동과 그 이력을 분석하였다. 연구결과: 항만시설 유지관리전략수립에 활용 가능한 성능개선비용(CAPEX)과 수선유지활동(OPEX)을 구별하고 이를 통한 유지관리전략수립에 활용 가능한 비용모델을 제시하였다. 결론: 이러한연구는 향후 시설물 중장기 투자의사결정에 큰 기여를 할 것으로 기대된다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.96-104
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• 2017

A one-shot system (device) refers to a system that is stored for a long period of time and is then disposed of after a single mission because it is accompanied by a chemical reaction or physical destruction when it operates, such as shells, munitions in a defense weapon system and automobile airbags. Because these systems are primarily related with safety and life, it is required to maintain a high level of storage reliability. Storage reliability is the probability that the system will operate at a particular point in time after storage. Since the stored one-shot system can be confirmed only through inspection, periodic inspection and maintenance should be performed to maintain a high level of storage reliability. Since the one-shot system is characterized by a large loss in the event of a failure, it is necessary to determine an appropriate inspection period to maintain the storage reliability above the reliability goal. In this study, we propose an optimal inspection policy that minimizes the total cost while exceeding the reliability goal that the storage reliability is set in advance for the one-shot system in which periodic inspections are performed. We assume that the failure time is the Weibull distribution. And the cost model is presented considering the existing storage reliability model by Martinez and Kim et al. The cost components to be included in the cost model are the cost of inspection $c_1$, the cost of loss per unit time between failure and detection $c_2$, the cost of minimum repair of the detected breakdown of units $c_3$, and the overhaul cost $c_4$ of $R_s{\leq}R_g$. And in this paper, we will determine the optimal inspection policy to find the inspection period and number of tests that minimize the expected cost per unit time from the finite lifetime to the overhaul. Compare them through numerical examples.

• 제어로봇시스템학회논문지
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• 제5권5호
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• pp.614-621
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• 1999

In this paper, the analytical appproaches are presented for jointly determining the profit-miximizing configuration of the fault-tolerance real time modular cell manufacturing system. The transient(time-dependent) analysis of Markovian models is firstly applied to modular cell manufacturing system from a performability viewpoint whose modeling advantage lies in its ability to express the performance that truly matters - the user's perception of it - as well as various performance measures compositely in the context of application. The modular cells are modeled with hybrid decomposition method and then availability measures such as instantaneous availability, interval availability, expected cumulative operational time are evaluated as special cases of performability. In addition to this evaluation, sensitivity analysis of the entire manufacturing system as well as each machining cell is performed, from which the time of a major repair policy and the optimal configuration among the alternative configurations of the system can be determined. Secondly, the recovery policies from the machine failures by computing the minimal number of redundant machines and also from the task failures by computing the minimum number of tasks equipped with detection schemes of task failure and reworked upon failure detection, to meet the timing requirements are optimized. Some numerical examples are presented to demonstrate the effectiveness of the work.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.257-262
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• 2016

Recently, the subject of reliability attracts a great deal of domestic and international attentions and the extensive research activities are being conducted as well. Such trend exists mainly due to the fact that the research on the subject of reliability not only contributes to the theoretical developments, but also may find a wide range of applications in practice over several fields. In particular, the research regarding the maintenance policy incorporating certain types of warranty for repairable system and its application is being performed extensively by many researchers, and their efforts seem more concentrated on developing new maintenance policies which minimize the expected operating cost incurred for replacement and repair of the system, while keeping the system at high reliability. Effective maintenance policy may reduce the operating cost and decrease the downtime of the system during its mission period and consequently, increase the productivity of the system. In this article, the major areas of interest in the field of reliability and its historic perspectives are given briefly and the theoretical aspects in several fields of reliability including the maintenance and warranty policies is also discussed. Furthermore, the current domestic situation regarding the education and research on reliability is presented, along with the importance of reliability theory and the difficulty of training reliability personnel. Finally, the author's opinion for effective education system is proposed.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.224-230
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• 2016

Purpose: Military maintenance involves corrective and preventive actions carried out to keep a system in or restore it to a predetermined condition. This research develops an optimal maintenance cycle for aviation oil testing equipment with acceptable reliability level and minimum maintenance cost. Methods: The optimal maintenance policy in this research aims to satisfy the desired reliability level at the lowest cost. We assume that the failure process of equipment follows the power law non-homogeneous Poisson process model and the maintenance system is a minimal repair policy. Estimation and other statistical procedures (trend test and goodness of fit test) are given for this model. Results: With time varying failure rate, we developed reliability-based maintenance cost optimization model. This model will reduce the ownership cost through adopting a proactive reliability focused maintenance system. Conclusion: Based on the analysis, it is recommended to increase the current maintenance cycle by three times which is 0.5 year to 1.5 years. Because of the system's built-in self-checking features, it is not expected to have any problems of preventative maintenance cycle.

• Asian Journal of Innovation and Policy
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• 제7권1호
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• pp.207-234
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• 2018

A manufacturer of a durable good typically purchases supplies, including parts for assembly - that are also useful for repairs - from independent "original equipment suppliers" with which it contracts. The manufacturer is a branded monopolist of its final assembled product. To put into effect also a monopoly of the replacement parts, it must stipulate in its arrangements with independent suppliers of the parts that they not supply such patented parts to any other buyer. Durable good owners would then only be able to obtain their requirements of replacement parts from the same company that supplied the durable. This would amount to a tie-in of replacement parts to the direct purchase of new durables. And that describes the apparently widespread practice of automobile manufacturers in India, as exposed in a recent case before the Competition Commission of India (Samsher Kataria v Honda Siel Cars India Limited and others). Here, I will argue that such tie-in enabled automotive manufacturers to more fully appropriate consumer surplus, which induced them to lower the price of new cars, sell more cars and also sell more repair parts. The tie-in expanded the auto parts industry and promoted new entry. The main restraint on expansion of India's automotive manufacturing is not monopoly. It is government protection in the form of tariffs on automobiles and auto parts.

• 시스템엔지니어링학술지
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• 제12권2호
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• pp.47-57
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• 2016

As the inventory costs of repairable items in military logistics continue to increase, many studies for optimal inventory level of these items are being carried out in advanced countries, including the US, to reduce these costs. Research on inventory level optimization for repairable items aimed to achieve the availability goal of a system with a MIME(Multi Indenture Multi Echelon) repair policy structure first began with Sherbrooke's METRIC and developed into various types. This research is to analyze and compare recent V-METRIC related studies to search for another variation in this field. This paper mainly looks at how to determine optimum inventory level for each repairable item to achieve a specific availability target within a limited budget, and also how to minimize inventory cost while achieving its availability target by determining optimal inventory level of each repairable item.