• 항공우주시스템공학회지
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• 제8권4호
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• pp.7-17
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• 2014

Objective of this paper is to introduce a new technology known as prognostics and health management (PHM) which enables a real-time life prediction for safety critical systems under extreme loading conditions. In the PHM, Bayesian framework is employed to account for uncertainties and probabilities arising in the overall process including condition monitoring, fault severity estimation and failure predictions. Three applications - aircraft fuselage crack, gearbox spall and battery capacity degradation are taken to illustrate the approach, in which the life is predicted and validated by end-of-life results. The PHM technology may allow new maintenance strategy that achieves higher degree of safety while reducing the cost in effective manner.

• 한국건설관리학회논문집
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• 제3권4호
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• pp.123-131
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• 2002

공공 시설물별 특성을 반영하기 힘든 Incremental Budgeting 모델에 근거한 유지관리예산의 산정 및 배정은 유지관리 요구와 투자예산간의 관련성을 더욱 격리시켜, 시설물의 조기 노후화를 발생시키고 있다. Incremental Budgeting 모델의 문제점을 개선하기 위한 노력이 일부에서 진행되고 있으나, 기존 모델의 테두리에서 이루어져 근본적인 처방이라 보기 힘들다. 공공 시설물 유지관리예산모델의 해결방안은 새로운 시각에서 바라보아야 한다 이러한 관점에서 $50\%$ 이상이 80년대 이전에 축조되었으며, 최근 대형화$\cdot$현대화되는 추세인 국방시설을 대상으로 문헌연구와 전문가 면담조사를 통해 적합한 유지관리예산모델을 선정하고, 이에 따른 현행 업무프로세스를 개선하였다.

• 패션비즈니스
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• 제11권1호
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• pp.86-96
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• 2007

The purpose of this study was to examine which variables affect customer relationship management in discount store focusing on satisfaction, trust and commitment. A total of 360 participants who had purchased fashion products in discount store were used in this study. The data was analyzed by factor analysis, correlation analysis and regression analysis using SPSS program. As the result, benefits, information, reputation, product, location, salesperson and price factor were extracted. The price, information, reputation, product and location variables had the effects on satisfaction, especially, price had the major effects on satisfaction. The satisfaction, information, salesperson, price and location had the effects on trust. The satisfaction, trust, information, benefits and product had the effects on commitment. The reputation variable had direct effect on relationship maintenance. Also, satisfaction, trust and commitment had the effects on relationship maintenance. Specifically commitment had higher effect on relationship maintenance than satisfaction and trust did. The results of this study would provide CRM marketing strategy for fashion marketers of discount store.

• 디지털융복합연구
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• 제15권9호
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• pp.211-221
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• 2017

반도체 산업은 임베디드 소프트웨어를 통해 운영 통제되는 자동화설비를 통해 첨단상품을 생산한다. 반도체를 생산하는 로봇과 각종 설비의 임베디드 소프트웨어 유지보수는 제품의 품질과 신뢰성 제고를 위한 필수적인 과정으로 반도체 장비의 라이프 사이클을 고려할 때 상당히 높은 비중을 차지하는 활동영역이다. 그러나 이 분야에 대한 학술적 관심사는 그리 높지 않는데, 본 연구에서는 반도체 웨이퍼 생산장비를 구동하는 소프트웨어 관련 문제로 보고된 사건을 대상으로 502개의 데이터를 무작위 추출방식으로 수집하여 임베디드 소프트웨어의 유지보수 노력에 영향을 미치는 요인들을 분석해 보았다. 결론으로 실무적인 시사점도 제시하였다.

• 품질경영학회지
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• 제41권2호
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• pp.301-322
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• 2013

Purpose: This study aims to determine the needs of customers who use railroads as a mode of transportation and propose customer-oriented improvements in railroad technology by making connections between customer needs and railroad technology. Methods: We primarily used two methods for this study, AHP and QFD. First, AHP was used to evaluate the relative importance among the different components of railroad technology. Second, the QFD was applied to make a link between customer needs and railroad technology. Results: Railroad technology is largely divided into development, maintenance, and support. Empirical results showed the following improvement priorities in development, vehicle, system, line, signal/communication, power, and structure, in maintenance, vehicle, signal/communication, line, process, power, and structure, and in support, safety/precaution, management, environmental energy, operations/logistics, and station. Conclusion: Recognizing limitations in measuring the level of railroad technology when using the existing 'Technology Growth Model,' we used AHP and QFD to explore improvement directions for customer-oriented railroad technology. By offering customer-oriented services based on this study, railroad service providers will be able to acquire competitive advantage in the market.

• 한국가시화정보학회지
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• 제21권2호
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• pp.34-45
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• 2023

When lithium-ion batteries operate out of the proper temperature range, their performance can be significantly degraded and safety issues such as thermal runaway can occur. Therefore, battery thermal management systems are widely researched to maintain the temperature of Li-ion battery cells within the proper temperature range during the charging and discharging process. This study investigates the cooling performance and isothermal maintenance of cooling materials by measuring the surface temperature of a battery cell with or without cooling materials, such as silicone oil, thermal adhesive, and phase change materials during discharge process of battery by the experimental and numerical analysis. As a result of the experiment, the battery pack filled with phase change material showed a temperature reduction of 47.4 ℃ compared to the case of natural convection. It proves the advanced utility of the cooling unit using phase change material that is suitable for use in battery thermal management systems.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권4호
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• pp.280-286
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• 2016

Purpose: Recently, Jiang defines the tradeoff B life to minimize a sum of life lost by preventive maintenance (PM) and corrective maintenance (CM) contribution parts and sets up an optimal replacement age of age replacement policy as this tradeoff life. In this paper, Jiang's model only considering the known lifetime distribution is extended by assigning different weights to two parts of PM and CM in order to reflect the practical maintenance situations in application. Methods: The new age replacement model is formulated and the meaning of a weight factor is expressed with the implied cost of failure under asymptotic expected cost model and also discussed with one-cycle expected cost criterion. Results: The proposed model is applied to Weibull and lognormal lifetime distributions and optimum PM replacement ages are derived with corresponding implied cost of failure. Conclusion: The new age replacement policy to escape the estimation of cost of failure in classical asymptotic expected cost criterion based on the renewal process is provided.

• 한국인터넷방송통신학회논문지
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• 제13권1호
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• pp.191-197
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• 2013

최근 스마트폰의 폭발적인 수요 확대와 모바일 관련 기술이 발전함에 따라 오프라인 현장에서 언제 어디서나 온라인 정보를 활용하여 실시간적으로 의사소통 및 업무처리를 할 수 있는 시스템의 요구가 증대되고 있다. 본 논문은 공동주택 및 각종 시설물 하자 관리와 유지보수 관리 업무에 적용될 수 있는 안드로이드 기반의 모바일 어플리케이션을 개발하여 스마트폰을 이용한 실시간 시설물 유지관리 시스템을 구현하는 방안을 제시한다. 제안하는 시스템은 시설물 유지관리를 위하 제반 데이터의 분류 및 표준화를 통해 웹 기반 시스템과 모바일 시스템간의 상호유기적인 통합관리 시스템 개발을 목표로 한다.

• 한국인공지능학회지
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• 제6권1호
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• pp.1-10
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• 2018

Compressed Air is an important energy source used in most factories nowadays. The automation trend using air compressor has been gradually increasing with the interest of the 4th industry in recent years. With the air compressor system, it is possible to construct the device at low cost and easily achieve automation and energy saving. In addition, With trend of FA, miniaturation and light weight manufacturing trend expand their use in the electronics, medical, and food sectors. Research method is to design the technology for the remote control of the following information as USN base. Development of flexible sensing module from real time observation module for fusion of IT technology in compressed air systems, design and manufacture of flexible sensing module, and realiability assessment. Design of real-time integrated management system for observation data of compressed air system - Ability to process observation data measured in real time into pre-processing and analysis data. This study expects unconventionally decreasing effect of energy cost that takes up 60~70% of air compressor layout and operation and maintenance management cost through USN(Ubiquitous Sensor Network) technology by using optimum operational condition from real time observation module. In addition, by preventing maintenance cost from malfunction of air compressor beforehand, maintenance cost is anticipated to cut back.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.269-269
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• 2001

Maintainability refers to the ease with which maintenance work can be done. It involves the process of ensuring that products can be easily and safely maintained and that the maintenance support requirement is minimized. When a product has a reasonably long life, the cost of operation and support during that life can greatly exceed the initial capital cost. The value to the customer of optimizing maintainability should be evident. Some effort and expense applied to achieving a product which can be easily and cheaply maintained will make very significant savings in the life cycle costs. In this paper, the International Standard IEC 60300-3-10, which is the application guide for maintainability, is considered. This standard can be used to implement a maintainability program covering the initiation, development and in-service phases of a product. It provides guidance on how the maintenance aspects of the tasks should be considered in order to achieve optimum maintainability. The elements of a maintainability program, which are maintenance policy and concept, maintainability studies, project management, design for maintainability, analysis and prediction methods, maintenance verification and validation, analysis of life cycle cost, maintenance support planning, and collection and analysis of maintenance data, are fully discussed in this paper.