• Journal of Computational Design and Engineering
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• 제2권1호
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• pp.16-25
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• 2015

Since construction projects are large and complex, it is especially important to provide concurrent construction process to BIM models with construction automation. In particular, the schematic Quantity Take-Off (QTO) estimation on the BIM models is a strategy, which can be used to assist decision making in just minutes, because 70-80% of construction costs are determined by designers' decisions in the early design stage. This paper suggests a QTO process and a QTO prototype system within the building frame of Open BIM to improve the low reliability of estimation in the early design stage. The research consists of the following four steps: (1) analyzing Level of Detail (LOD) at the early design stage to apply to the QTO process and system, (2) BIM modeling for Open BIM based QTO, (3) checking the quality of the BIM model based on the checklist for applying to QTO and improving constructability, and (4) developing and verifying a QTO prototype system. The proposed QTO system is useful for improving the reliability of schematic estimation through decreasing risk factors and shortening time required.

• 공학기술논문지
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• 제11권4호
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• pp.259-265
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• 2018

In this paper, we propose a test method to evaluate the reliability of the recliner sofa in the early stage of production. In order to develop the test method, we analyzed the failure mechanism occurring in the field and designed the performance test, environmental test, accelerated life test methods based on the analysis of failure mechanism. The failure mechanism is reproduced by applying the designed test. The reliability of the recliner sofa can be verified at the production stage through the proposed test method.

• 대한토목학회논문집
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• 제29권3A호
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• pp.181-188
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• 2009

본 연구에서는 현수교의 합리적인 시공방안 결정 및 구조안전성 평가에 대한 기초자료를 제시하였다. 기 연구된 현수교의 해석모델 및 신뢰성이론을 바탕으로 초기형상해석, 자유진동해석, 시공변수를 고려한 시공단계해석 및 신뢰성해석 등을 수행 할 수 있는 수치해석프로그램을 개발하였다. 현수교의 시공방안은 보강형의 시공순서, 시공방향 및 주경간과 측경간의 동시 시공성 등의 다양한 시공변수를 고려하여 설정하였다. 시공방안에 따른 동적시공단계해석은 작성된 해석프로그램에 의해 수행하였으며 주요부재의 응답특성을 검토하여 각각의 시공방안에 대한 장 단점을 제시하였다. 시공단계별 구조신뢰성해석은 자연적 불확실성을 고려하여 신뢰성지수 및 파괴확률을 산정함으로써, 설정된 시공방안에 따른 현수교의 안전성을 정량적으로 평가하였다. 아울러, 인위적 불확실성을 고려하여 산정된 해석결과에 대해 재평가하였으며, 시공단계 위험성의 주요 퍼센트 분포를 빈도수 히스토그램을 이용하여 제시하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권2호
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• pp.109-114
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• 2007

Fingerprints have been widely used in the biometric authentication because of its performance, uniqueness and universality. Lately, the speed of identification has become a very important aspect in the fingerprint-based security applications. Also, the reliability still remains the main issue in the fingerprint identification. A fast and reliable fingerprint matching algorithm based on the process of the 'self-nonself' discrimination in the biological immune system was proposed. The proposed algorithm is organized by two-matching stages. The 1st matching stage utilized the self-space and MHC detector string set that are generated from the information of the minutiae and the values of the directional field. The 2nd matching stage was made based on the local-structure of the minutiae. The proposed matching algorithm reduces matching time while maintaining the reliability of the matching algorithm.

• Communications for Statistical Applications and Methods
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• 제17권1호
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• pp.89-98
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• 2010

In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1397-1405
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• 2017

As the introduction of wind power is steadily increasing, negative effects of wind power become more important. To operate a power system more reliable, the system operator needs to recognize the maximum required capacity of available generators for a certain period. For recognizing the maximum capacity, this paper proposes a methodology to determine an optimal reserve requirement considering wind power, for the certain period in the mid-term perspective. As wind speed is predicted earlier, the difference of the forecasted and the actual wind speed becomes greater. All possible forecast errors should be considered in determining optimal reserve, and they are represented explicitly by the proposed matrix form in this paper. In addition, impacts of the generator failure are also analyzed using the matrix form. Through three main stages which are the scheduling, contingency and evaluation stages, costs associated with power generation, reserve procurement and the usage, and the reliability cost are calculated. The optimal reserve requirement is determined so as to minimize the sum of these costs based on the cost/reliability analysis. In case study, it is performed to analyze the impact of wind power penetration on the reserve requirement, and how major factors affect it.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권7호
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• pp.357-363
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• 2002

The target reliability values are defined for the train, signaling, rail track and electric power supply system of the LRT under development. The allocation of the reliability value is based on the failure rate and the failure type in the Korean subways. The reliability allocation in the train system is the made ore detail than others. The purpose of the allocation is to verify the reliability value of the results from each of the development stage, which could be the designing, manufacturing and purchasing work. The reliability of braking system, traction system, door system and other control system could be verified by establishing reliability models of these system. It could also enable us to estimate and analyse the reliability value and redo the work if necessary to achieve the shooting reliability value. A guide to the LRT reliability criteria is to be prepared after running test on the test track.

• 품질경영학회지
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• 제46권2호
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• pp.193-210
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• 2018

Purpose: The purpose of this study is to escape from the existing defense quality policy focused on government-led quality assurance for mass-produced items and to secure quality reliability of weapon systems through a defense quality policy paradigm shift based on designing a verification systems anchored on reliability through the enhancement of military supply quality control in the development stage, the enhancement of quality responsibility of the manufacturing contractor and other methods. Methods: For the shift to the quality-based defense quality policy, the status and the problems of the status quo are analyzed and the direction of future defense quality policy is suggested based on literature review of the concept of reliability and reliability in the field of defense, on case studies of global corporations and their quality policies, on the background on quality assurance in defense, and on case studies of quality policies in other government organizations, Results: Based on the case studies of quality policies in global corporations and other government agencies, the importance of preventive quality control from the early development stages, quality control based on the reliability of the materials and parts, and shift of the quality policy to a certification system to achieve these objectives were highlighted. Conclusion: To secure reliability of weapon system quality, the quality policy must be shifted to a system focused on reliability-based design and verification and there is a further need to enhance the operational efficiency and capacity of DTaQ based on studies and evaluation of weapon system reliability.

• 산업경영시스템학회지
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• 제43권2호
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• pp.65-71
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• 2020

Worldwide plant market keeps maintaining steady growth rate and along with this trend, domestic plant market and its contractors also maintain such growing tendency. However, in spite of its external growth, win-win growth of domestic material industry that occupies the biggest share in plant industry cost portion is extremely marginal in reality. Domestic plant material suppliers are required to increase awareness of domestic material brand by securing quality and reliability of international standard through improvement of design quality superior to that of overseas material suppliers. Improvement of design quality of plant material becomes an essential element, not an option, for survival of domestic plant industry and its suppliers. Under this background, in this study, priority and importance by each evaluation index was analyzed by materializing plant design stage through survey of experts and defining evaluation index by each design stage and based on this analysis result, evaluation index of stage-gate based decision-making process that may improve design quality of plant material was suggested. It is considered that by utilizing evaluation index of stage-gate based decision-making process being suggested in this study, effective and efficient decision-making of project decision-makers would be enabled and it would be contributory to improve design quality of plant material.

• 한국국방경영분석학회지
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• 제35권3호
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• pp.31-45
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• 2009

시스템의 성능과 안전성을 보장하기 위해서는 개발 초기부터 신뢰도에 대한 연구가 이루어져야 한다. 시스템의 목표 신뢰도를 수립하고, 이를 달성하기 위하여 하부시스템 및 부분품에 신뢰도를 할당해야 한다. 시스템의 획득 및 개발에 있어서 성능이 우수하고 비용이 저렴하더라도 고장이 빈번하게 발생한다면 원활한 임무 수행에 많은 영향을 미치고, 막대한 운영유지비용이 소요될 것이다. 본 연구에서는 신뢰도 할당 모형과 운영 유지비용과의 관계를 알아보기 위하여 기존의 알려진 신뢰도 할당 모형들을 검토 및 평가하였다. 신뢰도 할당모형의 평가는 차기 개발 함정용 디젤 엔진을 대상으로 하였으며, 다양한 신뢰도 할당 모형에 목표 신뢰도를 고려하여 신뢰도를 할당하고, 현재 운영하는 함정용 디젤 엔진의 자료를 바탕으로 시뮬레이션을 수행하여 운영유지비용을 최소화하는 신뢰도 할당 모형을 선정하였다.