• 제목/요약/키워드: Quality Inspections

검색결과 102건 처리시간 0.029초

이변량 정규분포 하에서 선별형 스크리닝 검사의 설계 (Design of Rectifying Screening Inspections under a Bivariate Normal Distribution)

  • 홍성훈;최익준;이윤동;이민구;권혁무
    • 품질경영학회지
    • /
    • 제35권4호
    • /
    • pp.147-158
    • /
    • 2007
  • Owing to the rapid growth in automated manufacturing systems, screening inspection becomes an attractive practice for removing nonconforming items, and it has been suggested that inspection will essentially become an inherent part of modem manufacturing processes. In this paper, we propose rectifying screening inspections which allow quality practitioners to use performance and surrogate variables interchangeably in real-time applications. Two screening inspections are considered; a statistically-based screening inspection to reduce the current proportion of nonconforming items to a specified AOQ(average outgoing quality) after screening, and an economically-based screening inspection where the tolerance limit is determined so that the expected total cost is minimized. It is assumed that the performance variable and the surrogate variable are jointly normally distributed. For two screening inspections, methods of finding the optimal solutions are presented and numerical examples are also given.

건설공사 현장점검 개선방안 마련을 위한 기초연구(설문조사 중심) (Improvement Direction of Construction Field Inspections : A Survey-Based)

  • 한재구;이수경
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
    • /
    • pp.188-189
    • /
    • 2015
  • This study was conducted a survey for suggesting direction of improvement of on­site inspections in Korean construction industry. The survey is limited perspective of owners, contractors and construction managers (including supervisors) about existing 'construction field inspection manual' with field inspections (eg. central inspection, central quality safety unit inspection etc.): focusing on stakeholder's perception and actual state of inspections.

  • PDF

모의비행훈련장치용 조종반력시스템의 자동-QTG 구현 (Auto Qualification Test Guide of Control Loading System for Flight Simulation Training Device)

  • 홍천한;신원석;정상진;김병수
    • 한국항공운항학회지
    • /
    • 제32권2호
    • /
    • pp.11-19
    • /
    • 2024
  • Flight simulators are crucial devices for aircraft piloting training and simulation, requiring regular inspections to maintain performance and operational quality. This study explores the development of an automated inspection system for flight simulators to automate quality inspections of control loading systems (CLS). While quality inspection of the control loading system (CLS) is essential for flight simulators, manual inspections are common practice. To address this, we developed an Auto Qualification Test Guide (Auto QTG) using artificial control logic and sensor data and applied it to the militarily simulator. Experimental results demonstrate that Auto QTG successfully automates quality inspections of CLS, enhancing accuracy and efficiency. This automated inspection system is expected to contribute to improving the operation and maintenance of flight simulators.

P-PIE 프로그램을 이용한 배관에서의 누설확률 평가 (Evaluation of Leak Probability in Pipes using P-PIE Program)

  • 박재학;신창현
    • 한국안전학회지
    • /
    • 제32권6호
    • /
    • pp.1-8
    • /
    • 2017
  • P-PIE is a program developed to estimate failure probability of pipes and pressure vessels considering fatigue and stress corrosion crack growth. Using the program, crack growth simulation was performed with an initially existing crack in order to examine the effects of initial crack depth distribution on the leak probability of pipes. In the simulation stress corrosion crack growth was considered and several crack depth distribution models were used. From the results it was found that the initial crack depth distribution gives great effect on the leak probability of pipes. The log-normal distribution proposed by Khaleel and Simonen gives lower leak probability compared other exponential distribution models. The effects of the number and the quality of pre-service and in-service inspections on the leak probability were also examined and it was recognized that the number and the quality of pre-service and in-service inspections are also give great effect on the leak probability. In order to reduce the leak probability of pipes in plants it is very important to improve the quality of inspections. When in-service inspection is performed every 10 years and the quality of inspection is above the very good level, the leak probability shows nearly constant value after the first inspection for an initially existing crack.

품질경영학회지 50주년 특별호: 통계적품질관리 분야 연구 리뷰 (Literature Review on the Statistical Quality Control in Journal of the KSQM for 50 Years)

  • 권혁무;홍성훈;이민구;임성욱
    • 품질경영학회지
    • /
    • 제44권1호
    • /
    • pp.1-16
    • /
    • 2016
  • Purpose: This paper reviews the papers on statistical quality control issues which are published in Journal of the Korean Society for Quality Management (KSQM) since 1965. The literature review is purposed to survey a variety of statistical quality control issues. Methods: By grouping all of statistical quality control issues into 3 categories:; quality inspections, control charts, and process capability analysis. Results: Grouping all of papers on statistical quality control published in journal of the KSQM for 50 years into 3 categories, we provide a chronological roadmap for individual categories, and summarize the contents and contributions of surveyed papers. Conclusion: The review paper is expected to provide future direction to improve statistical quality control theories and applications in manufacturing and service industries.

항공기용 임무 통제 컴퓨터(General Avionic Computer)의 품질인증시험절차 수립에 관한 연구 (Study of the Qualification Test Procedure for the General Avionic Computer for Aircraft)

  • 조장현
    • 한국산업융합학회 논문집
    • /
    • 제4권2호
    • /
    • pp.119-125
    • /
    • 2001
  • This paper discuss the Qualification Test Procedure which is composed of main functional and environmental tests for the localizing avionics and subsystems, especially the detail test approaches of General Avionics Computed(GAC) through the analysis of related technical data packages for the purpose of performance proof of final products. Quality assurance procedures are properly established with the several kinds of inspections and functional test items. They are called as process inspections, functional test, acceptance test procedure and qualification test procedure. The Qualification test procedure are composed of the analysis of original engineering design concept and shall be performed for the acquisition of the certification of the GAC's quality as well as the aquisition of the related techniques and engineering know-how items.

  • PDF

해상송전철탑 구조물의 주기점검을 통한 경년열화 변화특성 (Aging Deterioration for Electric Power Transmission Tower on Offshore Through Periodic Inspections)

  • 이호범;장일영
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제16권4호
    • /
    • pp.25-33
    • /
    • 2012
  • 해상송전철탑 구조물에 있어서 구조 및 재료 손상에 대해 주기적으로 안전점검을 실시하고, 그 결과를 이용한 수명관리(life management)의 시행은 적극 추천되는 일이다. 본 연구에서는 영흥도 시화호 내에 있는 총 6개의 해상송전철탑에 대해서 강재부재에 대해 3가지, 콘크리트 기초에 대해 5가지, 해수 중 강관파일 및 해수 자체에 대해 4가지 형태의 열화점검을 각각 수행하였다. 강재에 대한 점검 항목들은 외관조사, 부재두께, 도막상태 등에 대한 것이고, 콘크리트 기초에 있어서는 균열형상, 압축강도, 중성화깊이, 염화물 함유량 등에 대한 항목, 그리고 해중 강관파일에 있어서의 전위 및 양극조사에 따른 부식정도, 동영상 촬영 및 해수의 수질환경성 평가 등에 대한 항목이다. 이와 같은 정기적 열화점검은 연속 3년 동안 매년 10월경에 동일위치에 대해 평가하였다. 결과적으로 본 연구에서는 이러한 자료를 체계적으로 활용함으로써 해상송전철탑 안전성 유지관리에 유익하게 적용될 수 있는 새로운 열화지표를 개발하였다.

고속철도차량기술개발 표준 모니터링 절차에 대한 고찰 (A Study on Standard Monitoring Process in Development of High Speed Railway Vehicle)

  • 박민흥;김범진;김철수;최덕호
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 춘계학술대회 논문집
    • /
    • pp.528-535
    • /
    • 2011
  • According to railway safety regulations for securing the railway vehicle's quality and performance, it can be partly exempted that the performance tests and production inspections on the railway vehicles which are produced and assembled for the purpose of test and research. The reasons of this exemption are for ensuring maximum autonomy and for saving time considered the development period of railway vehicle. However, it was continuously demanded the necessity of supplementation on the confirmation about railway vehicle's quality & performance. Therefore, we added "The monitoring step" which is for securing the quality and performance in high speed railway vehicle's subsystem & compartment to supplement those tests & inspections in development. In this paper, based on a standard ABS(Activity Breakdown Structure) of railway vehicle and a WBS(Work Breakdown Structure) of the railway vehicle system, we investigate the necessity of monitoring in the High speed railway vehicle development. And by comparing and analyzing the essential requirements of international standard, IRIS(International Railway Industry Standard) & TSI(Technical Specification for Interoperability), we try to examine a standard monitoring procedure.

  • PDF

샘플링 검사가 수행되는 폐쇄형 생산 시스템의 성능분석 (Performance Evaluation of Closed Manufacturing Systems with Sampling Inspections)

  • 이효성
    • 한국경영과학회지
    • /
    • 제22권1호
    • /
    • pp.123-140
    • /
    • 1997
  • In this paper we consider closed flow line systems with samploing inspections. The total number of parts in the system is assumed to be N. The processings carried out of each station do not always meet the requirement of quality. Therefore, upon completion of its processing at each station, a part is inspected to determine whether the processings meet the requirement of quality or not. We assume that inspection are done on a random basis. If a part is found to be defective by an inspection, it is fed back to the apropriate station. Two different cases will be considered in this study : a three-station flow line system with infinite buffers and a two-station flow line system with finite buffers. For each case, we will develop an exact method to obtain the performance measures such as throughput, machinen utilization, average outgoing quality and manufacturing lead time. For the case of the two-station flow line system ith finite buffers, we will also develop an approximation method using a stage-aggregation technique. Then using buffers, we will also develop an approximation method using a stage-aggregation technique. Then using these results, we will try to find an optimal inspection policy which maximizes the expected net profit under a certain cost structure. Although we present the results only for the two or three station flow line system in this paper, the results obtained in this paper can be extended easily to the system which consists of more than two or three stations.

  • PDF

서비스 고정비용을 고려한 복수제품 품질시스템의 설계 (Design of A Quality System for Multi-Products with the Fixed Costs for Products Servicing)

  • 김성철
    • 한국경영과학회지
    • /
    • 제29권4호
    • /
    • pp.61-72
    • /
    • 2004
  • In this paper, we design sampling inspections and service capacities simultaneously for multi-products. Particularly, we extend Kim(2003) by introducing the fixed cost of providing services. We show that, due to the fixed cost considered, the cost function of a product is no longer linear or convex in terms of the level of service provision, and the total inspection is prefered to the small level of service capacity which results in high burden of the fixed cost. And we develop a simple framework to deal with this joint design problem for a product. Also we consider the problem of allocating the given number of the total service capacities among products. A dynamic programming algorithm is developed to determine the optimal allocation which minimizes the overall total cost of the system and the optimal allocation can be obtained with the considerably smaller computations than the total number of possible allocations. The results can be used to support planning decisions and to aid the joint design of inspections and service capacities for products.