• 제목/요약/키워드: global reliability

검색결과 690건 처리시간 0.032초

국내.외 위성항법시스템 모듈의 비교 평가 (Comparison of Global Positioning System Module Made by Domestic Products and Foreign Advanced Products)

  • 황순미;김철희;이관훈
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제8권3호
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    • pp.125-134
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    • 2008
  • Global Positioning System(GPS) is prospects item of information infrastructure with internet. Global Positioning System module made by domestic have high technology, but its international competitive power is very weak because of reliability. In this paper, we compare domestic products with foreign advanced products exactly, and confirm excellence of domestic products.

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크리깅 모델을 이용한 곱분해 기법에서 정확하고 강건한 통계적 모멘트 계산을 위한 전역모델의 비교 분석 (Comparison of global models for calculation of accurate and robust statistical moments in MD method based Kriging metamodel)

  • 김태균;이태희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.678-683
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    • 2008
  • Moment-based reliability analysis is the method to calculate reliability using Pearson System with first-four raw moments obtained from simulation model. But it is too expensive to calculate first four moments from complicate simulation model. To overcome this drawback the MD(multiplicative decomposition) method which approximates simulation model to kriging metamodel and calculates first four raw moments explicitly with multiplicative decomposition techniques. In general, kriging metamodel is an interpolation model that is decomposed of global model and local model. The global model, in general, can be used as the constant global model, the 1st order global model, or the 2nd order global model. In this paper, the influences of global models on the accuracy and robustness of raw moments are examined and compared. Finally, we suggest the best global model which can provide exact and robust raw moments using MD method.

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태양전지 신뢰성 정보은행 (Solar Cell Reliability Data Bank)

  • 소원섭;오수영
    • Current Photovoltaic Research
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    • 제2권3호
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    • pp.140-145
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    • 2014
  • The globally used PV qualification tests and reports the pass/fail only. Therefore, the reliability of new PV materials and parts can't be compared quantitatively with the reliability of the PV parts and materials in the market. Global PV materials and parts companies test and compare their materials, parts, and modules using the failure-to-test (FTT). However, it takes a long accelerated stress test (AST) until failure. It also needs to test the new and existing materials and parts. Therefore, it requires excessive equipment time and cost. In order to reduce the time and cost, a new reliability enhancement methodology has been developed. It tests the PV materials, parts, and modules in the global market and stores them in the PV reliability database. It reduces the time and cost of the comparison and enhancement of PV reliability. An example of the reliability enhancement of the PV encapsulant, EVA is presented.

도어스위치의 가속수명시험 (Accelerated Life Test for Door Switch)

  • 김상욱;장영기;문철희
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2005년도 학술발표대회 논문집
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    • pp.327-337
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    • 2005
  • Accelerated life test models and procedure are developed to assess the reliability of Door switch. The main function of door switch is to operate bulb lamp and fan motor. The accelerated life test method and test equipments are developed using the relationship between stresses and life characteristics of the products. Using the developed accelerated life test method, the parameters of the ALT model and life time distribution are estimated and the reliability of the Door S/W at use condition if assessed. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test time and costs of the tests remarkably.

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냉장고 도어스위치의 가속수명시험 (Accelerated Life Test for Door Switch of Refrigerator)

  • 유동수;김상욱;장영기;문철희
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제5권2호
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    • pp.273-287
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    • 2005
  • Accelerated life test models and procedure are developed to assess the reliability of Refrigerator door switch. The main function of door switch is to operate bulb lamp and fan motor in the refrigerating room. The accelerated life test method and test equipments are developed using the relationship between stresses and life characteristics of the products. Using the developed accelerated life test method, the parameters of the ALT model and life time distribution are estimated and the reliability of the Door S/W at use condition if assessed. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test time and costs of the tests remarkably.

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A New Reliability-Based Optimal Design Algorithm of Electromagnetic Problems with Uncertain Variables: Multi-objective Approach

  • Ren, Ziyan;Peng, Baoyang;Liu, Yang;Zhao, Guoxin;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • 제13권2호
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    • pp.704-710
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    • 2018
  • For the optimal design of electromagnetic device involving uncertainties in design variables, this paper proposes a new reliability-based optimal design algorithm for multiple constraints problems. Through optimizing the nominal objective function and maximizing the minimum reliability, a set of global optimal reliable solutions representing different reliability levels are obtained by the multi-objective particle swarm optimization algorithm. Applying the sensitivity-assisted Monte Carlo simulation method, the numerical efficiency of optimization procedure is guaranteed. The proposed reliability-based algorithm supplying multi-reliable solutions is investigated through applications to analytic examples and the optimal design of two electromagnetic problems.

Design of web-stiffened lipped channel beams experiencing distortional global interaction by direct strength method

  • Hashmi S.S. Ahmed;G. Khushbu;M. Anbarasu;Ather Khan
    • Structural Engineering and Mechanics
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    • 제90권2호
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    • pp.117-125
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    • 2024
  • This article presents the behaviour and design of cold-formed steel (CFS) web-stiffened lipped channel beams that primarily fail owing to the buckling interaction of distortional and global buckling modes. The incorporation of an intermediate stiffener in the web of the lipped channel improved the buckling performance leads to distortional buckling at intermediate length beams. The prediction of the strength of members that fail in individual buckling modes can be easily determined using the current DSM equations. However, it is difficult to estimate the strength of members undergoing buckling interactions. Special attention is required to predict the strength of the members undergoing strong buckling interactions. In the present study, the geometric dimensions of the web stiffened lipped channel beam sections were chosen such that they have almost equal distortional and global buckling stresses to have strong interactions. A validated numerical model was used to perform a parametric study and obtain design strength data for CFS web-stiffened lipped channel beams. Based on the obtained numerical data, an assessment of the current DSM equations and the equations proposed in the literature (for lipped channel CFS sections) is performed. Suitable modifications were also proposed in this work, which resulted in a higher level of design accuracy to predict the flexural strength of CFS web stiffened lipped channel beams undergoing distortional and global mode interaction. Furthermore, reliability analysis was performed to confirm the reliability of the proposed modification.

The Impact of the Competitiveness of Intermediate Software on Enterprise Results : a Case Study of Chinese Intermediate Software

  • Liu, Zi-Yang;Chen, Yi;Li, Hao
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2018년도 제58차 하계학술대회논문집 26권2호
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    • pp.258-261
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    • 2018
  • The purpose of this paper is to draw a conclusion on the impact of intermediate software on enterprise results. In this paper, product innovation and product reliability are especially used as analytical factors. An exploratory analytical study is conducted on the competitiveness of intermediate software, in the hope of gaining a new understanding of the competitiveness of intermediate software. Data are analyzed using such quantitative analytical tools as SPSS and AMOS. Using reliability analysis, validity analysis and structural equation model analysis, the final results are achieved. According to the analysis results, we can draw the following conclusions: the competitiveness of intermediate software has a positive impact on the innovation of software products. The competitiveness of intermediate software doesn't have a positive impact on the reliability of software products. Product innovation has a positive impact on enterprise results. Product reliability also has a positive impact on enterprise results. By analyzing the conclusions, we can make certain suggestions and draw implications on the competitiveness of China's software industry.

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신뢰성 국제 표준규격에 대한 연구 (The Study of International Reliability Standards Specifications)

  • 남경현
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제15권2호
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    • pp.101-107
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    • 2015
  • In this paper, we review the domestic reliability standards and its global counterparts IEC/TC 56 international reliability standards. Recently private transfers of reliability certification control tower has established in Korea. Some check points to consider regarding the control tower transfer process to the non-government organization are suggested. Also the IEC/TC 56 and its relevant reliability standards are introduced. Understanding of the IEC/TC56 system will be helpful for the time of non-government organization control tower transfer in the reliability certificate specification