• International Journal of Aeronautical and Space Sciences
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• 제8권2호
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• pp.126-131
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• 2007

In this paper, Monte Carlo Simulation (MCS) method was used as an uncertainty assessment tool for air flow, net thrust measurement. Uuncertainty sources of the net thrust measurement were analyzed, and the probability distribution characteristics of each source were discussed. Detailed MCS methodology was described including the effect of the number of simulation. Compared to the conventional sensitivity coefficient method, the MCS method has advantage in the uncertainty assessment. The MCS is comparatively simple, convenient and accurate, especially for complex or nonlinear measurement modeling equations. The uncertainty assessment result by MCS was compared with that of the conventional sensitivity coefficient method, and each method gave different result. The uncertainties in the net thrust measurement by the MCS and the conventional sensitivity coefficient method were 0.906% and 1.209%, respectively. It was concluded that the first order Taylor expansion in the conventional sensitivity coefficient method and the nonlinearity of model equation caused the difference. It was noted that the uncertainty assessment method should be selected carefully according to the mathematical characteristics of the model equation of the measurement.

• 한국안전학회지
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• 제23권2호
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• pp.37-44
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• 2008

The safety assessment for facility industry is now being periodically performed. For the purpose of scientific safety management, QRA(Quantitative Risk Assessment) is also being performed, and reliability data of the facilities is essential to perform the assessment. Generally, the existing safety assessment is performed by using the values announced in other industry processes, which result in the drop of reliability. In order to solve this problem, there is an urgent need to establish reliability database for the facilities. The most appropriate method is to perform a direct reliability analysis towards the facilities undergoing safety assessment. In this study, in compliance with the assessment method and procedure of OREDA-2002 handbook, the facility reliability data are collected, which include the calendar time and operational time in terms of different facility items, the number of failures in terms of different failure mode, the mean, standard deviation, lower limit and upper limit of failure rate, and the failure rate. And the data process method for this special occasion is also proposed when the number of failure is 0.

• 방송공학회논문지
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• 제14권2호
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• pp.197-209
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• 2009

스테레오 영상은 기존의 영상과는 달리 사용자에게 깊이감을 제공한다. 따라서 스테레오 영상을 평가하기 위해서는 새로운 화질평가 모델이 필요하다. 본 논문에서는 스테레오 영상을 위한 객관적 화질평가 방법을 제안한다. 제안된 화질평가 방법은 기존의 화질평가 모델을 기반으로 하여 블로킹 현상과 경계 영역에서의 열화 현상을 검출하였으며, 깊이 정보를 고려하여 시점 간 화질 격차 검출을 통해 알고리즘의 성능을 높이고자 하였다. 제안된 알고리즘의 성능 확인을 위해 스테레오 영상의 주관적 화질평가를 수행하였으며 주관적 화질평가와의 상관성 측면에서 제안 알고리즘이 PSNR에 비해 우수함을 확인하였다.

• 한국정밀공학회지
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• 제22권10호
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• pp.137-143
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• 2005

The integrity of steam generator tubes in nuclear power plant should be maintained sufficiently during operation. For sake of this, complicated assessment procedures are required such as fracture mechanics analysis, etc. The integrity assessment of tubes has been performed by using conventional deterministic approaches while there are many uncertainties to carry out a rational evaluation. In this respect, probabilistic integrity assessment is considered as an alternative method for integrity assessment. The objectives of this study are to develop an integrity assessment system based on probabilistic fracture mechanics and to predict the failure probability of steam generator tubes containing an axial through-wall crack. The developed integrity assessment system consists of three evaluation modules, which apply first order reliability method, second order reliability method and Monte Carlo simulation method, respectively. The system has been applied to predict failure probability of steam generator tubes and the estimation results showed a promising applicability of the probabilistic integrity assessment system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.418-419
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• 2006

After electricity power industry restructuring, "Long term power development plan", setting up by government, is replaced by "Basic plan of electricity supply and demand". In this basic plan, one of the most important factors is assessment of appropriate capacity margin. The benefit of GENCO is decided by the market price, and the price is largely affected by the level of reserve margin. As a consequence, appropriate reserve margin is determined by market power. However, Cost Based Pool(CBP) is a limited competitive market, and government policy for supply and demand is very important factor or reserve margin determination. This paper points out issues about existing reserve margin assessment method which is used in basic plan and suggests improved assessment method. In the case study, capacity margin is calculated by proposed assessment method and result shows the advantages of suggested method.

• 대한안전경영과학회지
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• 제14권3호
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• pp.151-158
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• 2012

The objective of this paper is to propose a method of how to perform risk assessment in the early stage of defense research and development for the acquisition of weapon systems. An advanced method for risk assessment and its associated objective functions are developed first based on the concept of systems engineering. The developed method is then applied to carry out the analysis of alternatives in the trade-off environments. As a case study, the multi-purpose training ship is considered, where it is performed using the notions of technology readiness levels, degrees of difficulty, and technology need values to facilitate design space visualization and decision maker interaction. It is noted that decision makers can benefit from our approach as an improved risk assessment method in the context of multi-criteria decision making.

• Asia pacific journal of information systems
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• 제16권3호
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• pp.193-203
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• 2006

Software reliability prediction is a statistical method to put in place a timely software development practice useful for objective assessment of bidders. The current study suggests one research method that enables reliability assessment of such previous projects by studying user satisfaction and project management history. If incorporated into the existing acquisition process, the reliability assessment method will further enhance objectivity and accuracy in bidder selection process. The GQM(Goal Question Metric) paradigm was used to identify assessment metrics for bidder evaluation and questionnaires were collected from users to create user satisfaction indexes. In addition, 'weight of evidence', the most appropriate categorical method, was used to isolate attributes of each variable that may contribute to reliability assessment.

• 산업경영시스템학회지
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• 제35권1호
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• pp.16-23
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• 2012

Recently, as organizational systems have become larger and more complicated, the evaluation for their efficiency and effectiveness has become more difficult but important. It is essential to understand the current strength and weakness of the organizational process. It can be a starting point for improving the efficiency and effectiveness of the organizational systems, because the quality of system outputs depend greatly on the capability of system process. Particularly in such process-based industries as semiconductor, energy or software industries, an assessment of process capability is more highlighted to gain knowledge of the expected quality and reliability of system outputs. As a result, much attention has been given to the issues of process capability assessment in the process-based industries. However, most of the previous research in those industries is based on case studies, a more generalized method for process capability assessment is in need for help more companies improve their processes. Therefore, this study aims to propose a process capability assessment method and apply the proposed method to an energy company. This research argues that the process capability is composed of individual and organizational capabilities of the process. Then, the concept of Capability Maturity Model Integration, which was initially suggested to evaluate the software development process, was introduced to develop the assessment tools and process. Finally, the proposed method was applied to a Korean company in the energy industry sector to verify its utility. The research outputs are expected to help more firms assess their process capability and ultimately improve the process.

• 한국산업정보학회논문지
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• 제9권1호
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• pp.92-102
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• 2004

자기 주도적 학습능력의 수준별 교육을 위한 평가 방법으로서, 수행평가는 문제해결 능력과 높은 사고 능력평가에 대한 한계점을 극복하고 수업의 질과 학교 정상화를 위한 계획으로 선호되고 있다. 그러나 수행평가는 평가 오류, 채점 공정성 문제, 신뢰도 및 객관성 등의 확보에 어려움 있다. 이런 문제점을 해결하고 수행평가 만족을 높이기 위하여, 본 논문에서는 회계원리 과목을 대상으로 수행평가에 대한 각 영역에서 영향을 주는 인자를 분석하여 퍼지 소속 함수를 설계하고, 이를 적용한 객관적이고 신뢰성 높은 수행평가 방법을 제시하고자 한다.

• 환경영향평가
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• 제21권5호
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• pp.813-821
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• 2012

Environmental and public health concern for the emission of air pollutants from burn-up process in waste incineration plants located in the vicinity of living environment was increased during the past decade. The purpose of this study was to suggest of the simple and rapid method of priority setting model for the decision of full-scale public health assessment. This method was consists of total 5-step. Step 1 was "secure the satellite map" and we can use the satellite map which serves from the website such as NAVER Co. Step 2 was "drawing mesh on the map" for catch the point of occupation of environmental sensitivity facilities, and step 3 was "identification and sorting of the facilities", Step 4 was "setting of weight" using the "weighted linear combination (WLC) method". Finally, all facility was sorted by score. As a result, we can set a priority of 145 facilities based on 177 facilities which managed in local government. Facilities in Seoul metropolitan area was high rank in priority list. On the other side, Facilities located at the country or rural area was low rank because of low occupation of the house and the environmental sensitivity facilities such as kindergarten, elementary school, and hospital. In this study, we suggested simple and rapid method that using for screening procedure of public health assessment.