• 제목/요약/키워드: Screening Procedure

검색결과 276건 처리시간 0.025초

Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings

  • Moseley, V.J.;Dritsos, S.E.;Kolaksis, D.L.
    • Structural Engineering and Mechanics
    • /
    • 제27권1호
    • /
    • pp.77-97
    • /
    • 2007
  • When assessing buildings that may collapse during a large earthquake, conventional rapid visual screening procedures generally provide good results when identifying buildings for further investigation. Unfortunately, their accuracy at identify buildings at risk is not so good. In addition, there appears to be little room for improvement. This paper investigates an alternative screening procedure based on fuzzy logic and artificial neural networks. Two databases of buildings damaged during the Athens earthquake of 1999 are used for training purposes. Extremely good results are obtained from one database and not so good results are obtained from the second database. This finding illustrates the importance of specifically collecting data tailored to the requirements of the fuzzy logic based rapid visual screening procedure. In general, results demonstrate that the trained fuzzy logic based rapid visual screening procedure represents a marked improvement when identifying buildings at risk. In particular, when smaller percentages of the buildings with high damage scores are extracted for further investigation, the proposed fuzzy screening procedure becomes more efficient. This paper shows that the proposed procedure has a significant optimisation potential, is worth pursuing and, to this end, a strategy that outlines the future development of the fuzzy logic based rapid visual screening procedure is proposed.

다 결정 대안을 갖는 대용특성을 이용한 경제적 양측 선별검사방식 (An Economic Two-Sided Screening Procedure Using a Correlated Variable with Multi-Decision Alternatives)

  • 홍성훈
    • 대한산업공학회지
    • /
    • 제21권3호
    • /
    • pp.387-396
    • /
    • 1995
  • For situations where there are several markets with different profit/cost structures, an economic two-sided screening procedure using a correlated variable is developed. It is assumed that the performance variable and the screening variable are jointly normally distributed. A profit model is constructed which involves selling price, cost incurred by imperfect quality, and screening inspection cost. Methods of finding the optimal screening procedure are presented and numerical examples are given.

  • PDF

생산공정의 최적공정평균 및 검사기준값의 결정기법 연구 (Determination of Optimal Process Mean and Screening specification Limits for a Production Process)

  • 이민구;최용선
    • 품질경영학회지
    • /
    • 제28권2호
    • /
    • pp.1-16
    • /
    • 2000
  • This paper considers the problem of determining the optimal process mean and screening specification limits of a surrogate variable associated with product quality under two-stage screening procedure. In two-stage screening, the surrogate variable is inspected first to decide whether an item should be accepted, rejected or additional observations should be taken. If additional observations are required, the performance variable of interest is then observed to classify the undecided items. Assuming that the performance variable and the surrogate variable are jointly normally distributed, the optimal process mean and the screening limits are obtained by maximizing the expected profit which includes selling price, production, reprocessing, inspection and penalty costs. A numerical example is presented and numerical studies are performed to compare the proposed two-stage screening procedure with single-stage screening procedures.

  • PDF

검사 오류를 고려한 다단계 선별절차에 관한 연구 (A Study on the Multistage Screening Procedure when Inspection Errors are Present)

  • 권혁무;김영진
    • 품질경영학회지
    • /
    • 제33권4호
    • /
    • pp.88-95
    • /
    • 2005
  • Multistage screening is a common practice when a component has a critical effect on the function of the assembly. A defect in a component might incur malfunction of an electronic device, resulting in a great amount of loss. Multistage screening, including duplicated screening inspections, may provide a good solution for this problem when inspection errors are present. In the company studied here, the manufacturing process of the multiple layer chip capacitor includes two-stage screening. In the first stage, screening inspection is performed repeatedly until no defects are found in the lot. In the second stage, sampling inspection is performed by a group of experts prior to shipment. In this article, we review the procedure used in the field and suggest a revised model of the multiple screening procedure and solution method for this situation. The usefulness of the proposed model is discussed through a practical example.

선별후 양품의 비율에 대한 제약조건을 갖는 선별검사방식의 경제적 설계 (Economic Design of Screening Procedures under the Constraint on the Proportion of Conforming Items after Screening)

  • 홍성훈
    • 대한산업공학회지
    • /
    • 제19권3호
    • /
    • pp.25-35
    • /
    • 1993
  • Economic screening procedures using a correlated variable are proposed to assure that the proportion of conforming items is above a desired level after screening. It is assumed that the performance variable and the screening variable are jointly normally distributed. Two screening procedures are considered. In the first screening procedure, all of the items are inspected on the screening variable. If an item fails to meet the screening specifications, it is rejected and excluded from shipment without inspection of the performance variable. In the second screening procedure, the item which fails to meet the screening specifications is inspected on the performance variable. If the value of the performance variable is within specifications the item is accepted, and the item is rejected otherwise. Cost models are constructed which involve cast from an accepted nonconforming item, cost from a rejected item, and quality inspection cost. Methods of finding optimal cutoff value on a screening variable are presented and numerical examples are given.

  • PDF

상관변수에 의한 공정관리 절차 (A Process Control Procedure Based on the Correlated Variable)

  • 권혁무
    • 대한산업공학회지
    • /
    • 제27권2호
    • /
    • pp.135-139
    • /
    • 2001
  • A process control procedure is suggested when screening inspection is performed with a surrogate variable correlated with the performance variable. Assuming bivariate normal distribution for the performance and screening variable, the procedure is designed on the basis of the time required for detecting process shift.

  • PDF

대용특성을 이용한 선별형 스크리닝 절차의 설계 (Design of Rectifying Screening Procedures Using a Surrogate Variable)

  • 홍성훈
    • 대한산업공학회지
    • /
    • 제32권1호
    • /
    • pp.51-60
    • /
    • 2006
  • When the nature of measuring a performance variable is destructive or very expensive, it is attractive to use a surrogate variable which is highly correlated with the performance variable and less expensive to measure. In this paper, we propose rectifying screening procedures using the performance and surrogate variables. Two screening procedures are considered; a statistically-based screening procedure to reduce the current proportion of nonconforming items to a specified lower value after screening, and an economically-based screening procedure where the screening limit is determined so that the expected cost is minimized. It is assumed that the surrogate variable given the performance variable is normally distributed with known mean and standard deviation. For two screening procedures, methods of finding the optimal solutions are presented and numerical examples are also given.

선별형 스크리닝 절차의 설계 (Design of Rectifying Screening Procedures)

  • 홍성훈;최익준
    • 한국경영과학회:학술대회논문집
    • /
    • 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
    • /
    • pp.70-77
    • /
    • 2006
  • When the nature of measuring a performance variable is destructive or very expensive, it is attractive to use a surrogate variable which is highly correlated with the performance variable and less expensive to measure. In this paper, we propose rectifying screening procedures using the performance and surrogate variables. Two screening procedures are considered; a statistically-based screening procedure to reduce the current proportion of nonconforming items to a specified lower value after screening, and a economically-based screening procedure where the screening limit is determined so that the expected cost is minimized. It is assumed that the surrogate variable given the performance variable is normally distributed with known mean and standard deviation. For two screening procedures, methods of finding the optimal solutions are presented and numerical examples are also given.

  • PDF

승객보안업무 성과 개선과 서비스 수준 향상을 위한 업무 책임 주체에 관한 연구 (A Study on Weight of the Factors for Improvement of Air Passenger Security Screening Performance and Service)

  • 신현삼;유광의
    • 한국항공운항학회지
    • /
    • 제13권4호
    • /
    • pp.29-42
    • /
    • 2005
  • The passenger security screening is a mandatory procedure for boarding the aircraft according to ICAO standard as well as national law of each country. The enhanced threat of terrorism have had the security procedure strengthened since 9/11 events. However the effectiveness of passenger screening is not satisfactory and the service level for passenger is getting worse because of tightened security measurements. This research studied the responsibility issue for the enhancement of the effectiveness and service quality in passenger security screening. The study concluded that a desirable responsibility assignment for passenger screening is to the airport authority at normal time and to the government authority at the time of high threat.

  • PDF

Knowledge, Attitude and Practice of the Pap Smear as a Screening Procedure Among Nurses in a Tertiary Hospital in North Eastern India

  • Thippeveeranna, Chamaraja;Mohan, Surekha Sadhana;Singh, Laiphrakpam Ranjit;Singh, Naorem Nabakishore
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제14권2호
    • /
    • pp.849-852
    • /
    • 2013
  • Background: Cancer of the uterine cervix is one of the most common cancers among women worldwide. Industrialized countries have dramatically reduced the incidence of mortality from cervical carcinoma in the last 50 years through aggressive screening programs utilizing pelvic examinations and Papanicolaou (Pap) smears but it still remains a major problem in the developing world. Objectives: This study was performed to determine knowledge, attitude and practice of Pap smear as a screening procedure among nurses in a tertiary hospital in north eastern India. Material and Methods: This cross sectional study was carried out with a questionnaire survey covering the socio demographic factors, knowledge, attitude and practices about Pap smear screening among 224 nurses in Regional Institute of Medical Sciences, Imphal, Manipur, India during December 2011. Results: Two hundred and twenty one participants (98.6%) had heard about cervical carcinoma but 18.3% lacked adequate knowledge regarding risk factors. Knowledge about the Pap smear was adequate in 88.8% of the respondents. Out of these, only 11.6% had Pap smear at least once previously. The most common reasons for non-participation in screening were lack of any symptoms (58.4%), lack of counselling (42.8%), physician does not request (29.9%) and fear of vaginal examination (20.5%). Conclusion: Although knowledge of Pap smear as a screening procedure for cervical cancer is high, practice is still low. The nurses who should be responsible for opportunistic screening of women they care for are not keen on getting screened themselves. If we can improve the practice of Pap smear screening in such experts, they should be able to readily provide appropriate and accurate information and motivate the general population to join screening programs.