• 제목/요약/키워드: Reliability demonstration

검색결과 118건 처리시간 0.023초

와이블 분포를 이용한 플랩구동장치의 무고장 가속수명시험 (No-Failure Accelerated Life Test of Flap Actuating System using Weibull Distribution)

  • 조현준;이인호;김상범;박상준;양명석
    • 항공우주시스템공학회지
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    • 제10권1호
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    • pp.51-58
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    • 2016
  • In this paper, we present some results on No-failure accelerated life test of aerial vehicle for reliability demonstration. The design of general accelerated life test consists of the three phases: 1) Estimating normal life test time of a single product from Weibull distribution model; 2) Determining the acceleration factor (AF) by utilizing the relation between the life of mechanical components and the applied torque; 3) Calculating the accelerated life test time, which comes from dividing the estimated normal life test time into AF. Then, we applied the calculated life test time to the real reliability test of the flap actuating system, while considering the requirement specification for mechanical components and operating environment of the actuation system. Real experimental processes and results are presented to validate the theory.

극값 분포 특성을 가진 소프트웨어 신뢰성 보증 모형에 관한 비교연구 (The Comparative Study of the Warranty Cost Model for Software Reliability Time Based on Extreme Value Distribution)

  • 김희철
    • 한국통신학회논문지
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    • 제34권6B호
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    • pp.623-629
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    • 2009
  • 본 연구에서는 소프트웨어 제품을 개발하는 과정에서 보증기간을 고려하여 사용자에게 인도하는 시기를 결정하는 방출시기에 관한 모형의 비교 연구이다. 실증 비교 결과 지수화 소프트웨어 신뢰성장모형에서는 보증기간이 증가함에 따라 초기에는 최적방출시기가 증가했으나 점차 거의 유사한 방출시기를 나타내고 있으며 이와 반대로 불완전한 디버깅 소프트웨어 신뢰성장 모형에서는 초기에는 최적방출시기가 감소하였으나 보증기간이 길수록 소폭 증가하는 패턴을 보이고 있으며 제안된 극값모형은 점차적으로 증가하는 형태를 가진다는 결론을 도출 할 수 있다. 이러한 연구결과를 통하여 소프트웨어 개발자들은 보증기간과 방출최적시기의 관계를 파악함으로서 소프트웨어 개발 시 사전정보로 활용 할 수 있으리라 사료된다.

설계 민감도와 신뢰도 분석에 근거한 전자기기의 다목적 최적화 (Multi-Objective Optimization of Electromagnetic Device Based on Design Sensitivity Analysis and Reliability Analysis)

  • 렌지얀;장전해;박찬혁;고창섭
    • 전기학회논문지
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    • 제62권1호
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    • pp.49-56
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    • 2013
  • In this paper, for constrained optimization problem, one multi-objective optimization algorithm that ensures both performance robustness and constraint feasibility is proposed when uncertainties are involved in design variables. In the proposed algorithm, the gradient index of objective function assisted by design sensitivity with the help of finite element method is applied to evaluate robustness; the reliability calculated by the sensitivity-assisted Monte Carlo simulation method is used to assess the feasibility of constraint function. As a demonstration, the performance and numerical efficiency of the proposed method is investigated through application to the optimal design of TEAM problem 22--a superconducting magnetic energy storage system.

Marketing Strategies for Improving Customer Attitude Using Airline Advertising Model: Focusing on Corporate Image and Brand Loyalty

  • OH, Ah-Hyun;PARK, Hye-Yoon
    • 유통과학연구
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    • 제18권4호
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    • pp.13-26
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    • 2020
  • Purpose: In this study, we will explore how the attributes of the airline's advertising model affect the corporate image and brand loyalty and the medium effect of the corporate image. Research design, data and methodology: Data collection for empirical analysis of this study was conducted online for about seven months from Jan. 2 to July 12, 2019, and was confirmed as part 292 of the final effective sample and used for demonstration analysis. Results: The property of the advertising model shown to have a significant impact in corporate image and brand loyalty. The property of the advertising, reliability and professionalism shown to have an impact in the social responsibility, but attractiveness is its responsibility and brand loyalty. Corporate images have been shown to play a meaningful role in the impact of advertising models on brand loyalty. Conclusions: The attributes of the airline's advertising model are divided into four categories, and reliability has the most influence on the image of a company and the formation of brand loyalty. The impact of the attributes of the advertising model on the relationship between corporate image and brand loyalty was investigated through an empirical analysis, and several implications were derived.

ACT를 이용한 AMI 보안 분석 (Security Analysis of AMI Using ACT)

  • 위미선;김동성;박종서
    • 정보보호학회논문지
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    • 제23권4호
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    • pp.639-653
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    • 2013
  • 스마트 그리드는 기존 전력망에 IT 기술을 접목하여 에너지 효율을 최적화하는 차세대 지능형 전력망으로 미국, 유럽, 일본 등 전 세계적으로 기술개발이 이루어지고 있으며 실증사업을 추진하고 있다. 최근 스마트 그리드에 대한 공격 사례가 증가되고 있으며 개인정보의 사용 및 유출의 피해가 높아지고 있다. 전력망이 더욱 복잡해지고 상호 연결됨에 따라 보안 분석과 평가에 대한 노력이 점차 중요해지고 있다. 본 논문에서는 스마트 그리드의 핵심 기술인 AMI(Advanced Metering Infrastructure)의 공격과 공격에 대한 대응책을 ACT(Attack Countermeasure Tree)를 이용하여 모델링 하였다. 보안 분석은 확률이 있는 경우와 확률이 없는 경우로 나누어서 수행하였다. 이러한 모델을 가지고 SHARPE(Symbolic Hierarchical Automated Reliability and Performance Evaluator)로 구현하여 다양한 경우의 확률과 ROA, ROI, Structure Importance, Birnbaum Importance에 대해 계산하였다.

A Study on HMR Selection Attributes and Health Values of College Students

  • CHA, Seong-Soo;NOH, Eun-Jeong
    • 산경연구논집
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    • 제11권10호
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    • pp.17-25
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    • 2020
  • Purpose: The purpose of this study is to narrow the target down to college students representing single-person households to identify the main attributes of their choice of Home Meal Replacement(HMR) and to look at the impact on satisfaction and repurchase intentions. Research design, data and methodology: An online survey was conducted for consumers who purchased HMR products at least once and a total of 264 questionnaires were used for demonstration analysis. The collected data have verified for validity and reliability between measurement variables through exploratory factor analysis and reliability analysis. Results: As a result, curiosity, economy, safety, and brand, which are HMR selection attributes that university students' value, have a significant impact on satisfaction, and satisfaction has a significant impact on the intention of repurchase, a variable of behavior. In addition, the adjustment effect of health value pursuit was significant only in safety attributes. Conclusions: This study divided the target group to examine what the HMR selection attributes of single-person college students are, the main consumer of HMR, and how selective attributes affect satisfaction and willingness to repurchase. In the process, we wanted to find out if there was a moderating effect on the health-oriented values in the dietary lifestyle.

태양열 온수기 실증연구를 통한 성능 평가 (Performance Evaluation of Solar Water Heating System Using Proof Test)

  • 김재열;곽이구;양동조;최철준;김홍건
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.597-601
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    • 2006
  • The advantages of solar energy are that it is renewable, infinite supplied and environmentally safe energy source. However, solar energy related products have the problems such as the limitation for installation, problems in maintenance and insufficient reliability which have been the barrier to consumers to satisfy the purchase need for solar heat related products. In this regard, in order to support the solar energy related companies the necessity for various technical information required for the commercialization of new products such as various performance test necessary for the certification of solar energy system, standardization for facilities and products, performance evaluation method and the measurement of performance is suggested. The purpose of this paper is to design the monitoring system for positive tests of system linked household hot water system using solar heat out of various solar energy systems, to establish an analysis and monitoring system for performance maintenance and operation technique, and to configure the centralized detection network by utilizing remote monitoring system. This research also aims at conducting monitoring for operation and performance evaluation in relation to database establishment and analytical evaluation and at describing the method of enhancing the reliability of solar energy system through the development of performance evaluation program.

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안전한 고객수송서비스를 위한 KTX-II RAMS 적용기준 (KTX-II RAMS Application Standard for Safety of Passenger Transportation Service)

  • 차재환;정인수;조광우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1525-1538
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    • 2008
  • Currently, it has been a fashion to include RAMS of rolling stock in the order for purchasing the rolling stock. However, it's only to suggest a qualitative value or an ideal target without giving or demonstrating actual RAMS target, with only demonstrating passive RAMS by the data provided by the manufacturer. In the case of KTX project of 100 cars of KTX-II contracted in June 2006, their target has been suggested from the previous RAMS application standard and it aimed to achieve the reliability level of equivalent high speed rolling stock. Afterward, as actual KTX-II RAMS Plan and RAMS Demonstration Plan has been prepared and approved, it has been the first problem to secure the reliability and safety in order to introduce the new high speed rolling stock(KTX-II) successfully and we actually tried to apply overseas RAMS standard, KTX samples, electric railcar MTRC and rolling stock samples. This Report was dealt world trends of Railway RAMS standard, KTX-II RAMS Specifications, the present condition of KTX-II RAMS performance and development a way of KTX-II RAMS, We hope the "KTX-II RAMS Application Standard for Safety of Passenger Transportation Service" is served as an opportunity for the basic research for establishing and demonstrating RAMS target of components or parts composing the rolling stock system.

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Designing an Evaluation Method for the in-situ Impact Strength of Rollable Devices

  • Hyojung Son;Ki-Yong Lee;Byoung-Seong Jeong
    • 공업화학
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    • 제35권2호
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    • pp.148-153
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    • 2024
  • In this study, a methodology for evaluating impact strength in rollable devices was developed, focusing on measuring impact strength and evaluating rolling and unrolling durability simultaneously, with findings reported from tests on a real demonstration unit. The study utilized a flexible and rollable polyimide (PI) substrate for the evaluations. The chosen parameters for this methodology were a flat-type impactor, weights of 300 g, 500 g, and 1000 g, a rolling shaft ranging from 30 R to 5 R, and the positioning of the impactor. The results revealed that the difference in defect rates when comparing the 300 g and 500 g weights was minimal. However, the adoption of a 1000 g weight markedly increased the defect count due to damage to the PI film's surface. Furthermore, an uptick in rolling and unrolling cycles led to more pronounced surface scratches on the PI film. These methods and findings are poised to make a substantial contribution towards refining reliability testing for a wide array of rollable device applications, including smartphones, watches, pads, and wearable technology.

전압플리커 저감과 역률 보상 기능을 갖는 배전용 STATCOM의 실계통연계 운전결과 분석 (Analysis of the Distribution STATCOM for Improving the power factor and Mitigation of Voltage Flicker in Real System)

  • 오관일;전영수;박상태;추진부
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.245-248
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    • 2000
  • This paper presents the test and operation results of the domestic demonstration of the reactive power compensation device called STATCOM (STATic COMpensator). The object of the paper is to describe the reliability of the unit based on the extensive operation databases. By controlling reactive power, the technology offers utilities the opportunity for increased efficiency and their capabilities will permit transmission planners make the best use of their existing transmission resources STATCOM is a custom power device in a way and can be used in a similar way for the dynamic compensation of power transmission systems, mitigation of voltage flicker and improving the power factor. It is shown that the STATCOM has clear advantages in areas such as: mitigation of voltage flicker and improving power factor.

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