• Structural Engineering and Mechanics
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• 제70권5호
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• pp.563-570
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• 2019

To analyze the seismic reliability of concrete rectangular liquid storage structures (CRLSSs), assuming that the wall thickness and internal liquid depth of CRLSSs are random variables, calculation models of CRLSSs are established by using the Monte Carlo finite element method (FEM). The principal stresses of the over-ground and buried CRLSSs are calculated under three rare fortification intensities, and the failure probabilities of CRLSSs are obtained. The results show that the seismic reliability increases with the increase of wall thickness, whereas it decreases with the increase of liquid depth. Between the two random factors, the seismic reliability of CRLSSs is more sensitive to the change in wall thickness. Compared with the over-ground CRLSS, the buried CRLSS has better reliability.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권1호
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• pp.32-40
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• 2016

Purpose: The purpose of this study is to analyze the effect of sampling points on accuracy of storage reliability estimation for one-shot systems by assuming a weibull distribution as a storage reliability distribution. Also propose method for determining of sampling points for increase the accuracy of reliability estimation. Methods: Weibull distribution was divided into three sections for confirming the possible to estimate the parameters of the weibull distribution only some section's sample. Generate quantal response data for failure data. And performed parameter estimation with quantal response data. Results: If reduce sample point interval of 1 section, increase the accuracy of reliability estimation although sampling only section 1. Even reduce total number of sampling point, reducing sampling time interval of the 1 zone improve the accuracy of reliability estimation. Conclusion: Method to increase the accuracy of reliability estimation is increasing number of sampling and the sampling points. But apply this method to One-shot system is difficult because test cost of one-shot system is expensive. So propose method of accuracy of storage reliability estimation of one-shot system by adjustment of the sampling point. And by dividing the section it could reduce the total sampling point.

• 한국군사과학기술학회지
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• 제18권3호
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• pp.267-274
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• 2015

It is necessary to both analyze root-cause of non-conformance of effective illumination time to the specification, and estimate the storage lifetime for 81 mm illuminating projectile stockpiled over 10 years. In this paper, aging mechanism of magnesium flare material due to long-term storage was supposed, and two-stage tests, pre-test and main test based on accelerated degradation tests were performed. Field storage environment of moistureproof was set up, and illumination times in the accelerated degradation tests for temperatures 60 and $70^{\circ}C$ were measured. Then, storage reliability of the projectile was estimated through analyzing the measured data and applying distribution-based degradation models to the data. The $B_{10}$ life by which 10 % of a population of the projectiles will have failed at storage temperature of $25^{\circ}C$ was estimated about 7 years.

• 품질경영학회지
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• 제41권3호
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• pp.381-394
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• 2013

Purpose: Nowadays, Mobile Cloud Storage services are used widely. For sustainable use of this service, we need to determine what factors affect satisfaction. Therefore, the purpose of this study is to identify the factors that influence satisfaction. Methods: To analyze factors that influence satisfaction, this study sets the factors into three dimensions such as service quality, perceived risk, and individual characteristics and analyze the causal relationship between influence factors and satisfaction through Structural Equation Model. Results: The results of this study are as follows; among service quality, user interface and reliability influenced satisfaction, but adaptability did not have any influence. Perceived risk of illegal access had a negative influence on satisfaction, while perceived risk of privacy leakage did not have significant influence on satisfaction in perceived risk. At last, self-efficacy had a significant influence on satisfaction. Conclusion: We identified the influence factors that influence satisfaction. Our findings will be necessary for Mobile Cloud Storage service providers to strengthen their service.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.51-58
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• 1998

This study is to define the Automated Container Terminal(ACT) and container terminal system. Also, we analyze the present condition of the container terminal system in Pusan port and its automation level by systems approach. And this paper aims at evaluating on the priority of R&D investment until the beginning of the second stage of New Pusan Port Project(2006). In this process we have considered 8 factors (cost, labor, area, time volume, reliability, safety, convenience) to analyze 6 subsystems. The priority order of R&D until target year by sub-systems is as follow : Cargo Handling System〉Transfer System〉Port Entry System〉Storage System(Distribution&Manufacturing System included)〉Inland Transport System〉Port Information System.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1072-1079
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• 2014

This paper introduces a coordinated droop control for the stand-alone DC micro-grid, which is composed of photo-voltaic generator, wind power generator, engine generator, and battery storage with SOC (state of charge) management system. The operation of stand-alone DC micro-grid with the coordinated droop control was analyzed with computer simulation. Based on simulation results, a hardware simulator was built and tested to analyze the performance of proposed system. The developed simulation model and hardware simulator can be utilized to design the actual stand-alone DC micro-grid and to analyze its performance. The coordinated droop control can improve the reliability and efficiency of the stand-alone DC micro-grid.

• 한국국방경영분석학회지
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• 제37권1호
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• pp.71-85
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• 2011

전장관리체계의 전자결재시스템은 가용성과 신뢰성이 최우선이기 때문에 서버와 스토리지를 가장 신뢰성 있게 구축하지 위해 SAN(Storage Area Network)을 이용하고 있다. 본 논문에서는 전장관리체계 내 전자결재 시스템에서 중요한 군사자료가 저장되는 SAN을 대상으로 보안취약점을 분석하고, 분석된 결과를 바탕으로 가상 공격 시나리오를 작성하여 내부자에 의한 자료 유출이 가능할 수 있음을 실험을 통해 검증한 후, 내부자에 의한 자료 유출 위협을 방지할 수 있는 새로운 개념의 사용자 역할 기반 스토리지 암호화 기법을 제안한다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제1권2호
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• pp.71-78
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• 2012

디지털 자동차운행기록계는 교통안전법에 따라 자동차의 운행상황과 교통사고 상황과 함께 자동차의 속도, 거리, 브레이크 상황, 가속도, GPS 위치 등을 자동적으로 저장장치에 기록하는 장치이다. 유럽에서는 디지털 자동차운행기록계 장착이 2005년부터 모든 트럭에게 의무화되어 있고, 대한민국은 2011년부터 신규로 등록되는 사업용 차량은 의무적으로 장착해야 하며, 해가 지날수록 의무적으로 장착해야하는 자동차의 범위가 확대되어가고 있다. 이 장치는 운전자의 일일 운행 현황 분석 및 사고 분석을 위하여 사용된다. 자동차 사고는 장치의 안정성을 예측불가능하게 한다. 그래서 불확실한 상황아래에서 최대한 안정적으로 데이터를 저장할 수 있는 기술은 매우 중요하다. 우리는 실제 디지털 자동차 운행기록계를 설계하고 구현하였다. 본 논문은 이 장치의 설계와 구현에 있어서 저비용의 하드웨어 자원으로 안전하게 대용량 데이터를 저장하기 위해서 저용량이지만 안정적인 1차 저장장치와 대용량을 저비용으로 구현한 2차 저장장치로 구성된 계층적 저장 기법을 제안한다. 1차 저장장치는 용량이 SLC 낸드 플래시 메모리를 사용하여 로그 구조 형식으로 데이터를 저장한다. 로그 구조의 단점인 느린 부팅 문제를 해결하기 위해 역방향 부분 검색 기법을 제시한다. 이 방법은 1차 저장장치의 부팅 시간을 50분의 1로 감소시킨다. 추가적으로 사고 순간의 데이터를 신속하게 데이터를 저장하는 기법도 제시한다. 이 방법으로 저비용의 내장형 시스템에서 사고순간의 운행기록 시간을 일반적인 방법의 저장시간의 1/20만큼 단축하였다.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.592-598
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• 2017

유도무기(정확히 유도탄)는 고가의 장비로서 발당 0억을 호가하며, 납품 후 장기간 저장되는 특성을 반영하여 설계되므로 내부 구성품은 물론 유도탄 자체도 매우 높은 신뢰도를 가지게 된다. 이러한 유도탄의 신뢰도는 샘플링 검사결과를 바탕으로 전체 모집단의 신뢰도를 추정하여야 하나, 개발 간에는 개발기간이나 일정, 비용 등의 현실적인 문제로 실제 검사보다 수학적 분석이나 가속수명시험 등을 이용하여 저장신뢰도를 예측한다. 그러나 개발 시 제시되는 저장신뢰도는 예측값으로 실제 저장신뢰도와는 차이가 있을 것임에도 불구하고, 현재 우리 군(軍)은 유도탄 개발시 예측된 저장신뢰도를 기준으로 저장관리(주기검사)를 실시하고 있다. 이에 본 연구는 우리나라에서 10년 이상 저장되어 데이터가 축척된 ${\triangle}{\triangle}$유도탄의 야전점검 데이터를 수집하여 실제 저장신뢰도를 분석하고 현재 실시되고 있는 검사주기의 타당성 검토와 실질적인 저장신뢰도 확인방법을 제시하고자 작성되었다. 최근 실시된 특별검사결과를 토대로 저장신뢰도를 분석한 바 검사주기는 18년 이상으로 연장 가능함이 확인 되었고, 이에 따라 검사주기의 재 설정 및 실질적인 저장신뢰도 확인 방법을 제안한다.

• 한국농공학회논문집
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• 제61권6호
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• pp.93-101
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• 2019

This study aims to analyze the influences of applications of two different evapotranspiration (ET) estimation methods on the irrigation water requirements (IWR) for paddy rice and water supply reliability of agricultural reservoirs. The modified Penman (MP), traditional method, and the Penman-Monteith (PM), the new adopted method, were applied on 149 reservoirs located in Honam province for this study. The weather date was used from 1987 to 2016, and analysed the trends of temperature and rainfall during rice growing season between past and current 10 years respectively. The increased average temperature and rainfall were observed from the current 10 years compared to the past years. This phenomena impacts on the results of ET and IWR estimations with decreased IWR obtained from high rainfall regions and increased ET obtained high temperature regions. For the comparisons of application results of two ET approaches, the PM method showed lower ET and IWR, and hence more reliable storage capacity of the reservoirs respect to water supply to paddy fields. The results also showed that the influences of different ET methods applications on the water supply reliability of reservoirs are negligible for the cases of over 3.7 watershed ratio and 670 mm unit reservoir storage, while significant variations of the results obtain from the applications between two ET approaches for the opposite cases. Further studies are necessary to consider various field conditions for practical applications of the PM method estimating ET in the fields of paddy farming.