• 제목/요약/키워드: Pattern repair

검색결과 163건 처리시간 0.028초

개선지수를 고려한 주기적 예방보전의 최적화에 관한 연구 (Optimal Periodic Preventive Maintenance with Improvement Factor)

  • Jae-Hak Lim
    • 품질경영학회지
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    • 제31권3호
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    • pp.193-204
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    • 2003
  • In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.

BAYESIAN APPROACH TO MEAN TIME BETWEEN FAILURE USING THE MODULATED POWER LAW PROCESS

  • Na, Myung-Hwa;Kim, Moon-Ju;Ma, Lin
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제10권2호
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    • pp.41-47
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    • 2006
  • The Renewal process and the Non-homogeneous Poisson process (NHPP) process are probably the most popular models for describing the failure pattern of repairable systems. But both these models are based on too restrictive assumptions on the effect of the repair action. For these reasons, several authors have recently proposed point process models which incorporate both renewal type behavior and time trend. One of these models is the Modulated Power Law Process (MPLP). The Modulated Power Law Process is a suitable model for describing the failure pattern of repairable systems when both renewal-type behavior and time trend are present. In this paper we propose Bayes estimation of the next failure time after the system has experienced some failures, that is, Mean Time Between Failure for the MPLP model. Numerical examples illustrate the estimation procedure.

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Carbon Fibers for the Repair of External Abdominal Hernias in Bovines, Caprines and Canines: A Review of 18 Clinical Cases

  • Kumar, Naveen;Sharma, A.K.;Gangwar, A.K.;Maiti, S.K.;Gupta, O.P.;Kumar, N.;Mathur, R.B.
    • Carbon letters
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    • 제7권2호
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    • pp.81-86
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    • 2006
  • During a 3-year period (2001-2004) 18 animals were surgically treated because of abdominal wall defects (hernia). Out of 18 animals 8 were bovines, 5 caprines and 5 canines. In each case the defect was bridged with carbon fibres. Carbon fibres were placed either in simple interrupted pattern or as mattress overlapping pattern. All the cases were successfully treated and no complication was observed up to six months postoperatively.

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집속이온빔의 가공 공정 메카니즘 연구 (Manufacturing Mechanism of FIB-CVD using Focused Ion Beam)

  • 강은구;최병열;이석우;홍원표;최헌종
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.925-928
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    • 2004
  • The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. This paper was carried out some experiments and verifications of mechanism on FIB-CVD using SMI8800 made by Seiko. FIB-CVD has in fact proved to be commercially useful for repair processes because the beam can be focused down to 0.05$\mu\textrm{m}$ dimensions and below and because the same tool can be used to sputter off material with sub-micrometer precision simply by turning off the gas ambient. Recently the chemical vapour deposition induced ion beam has been required more deposition rate and accurate pattern because of trying to manufacture many micro and nano parts. Therefore this paper suggested the optimization parameters and discussed some mechanism of chemical vapour deposition induced ion beam on FIB-CVD for simple pattern.

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고압전동기 고정자 권선의 운전중 부분방전 분석 (Analysis of On-Line Partial Discharge in High Voltage Motor Stator Windings)

  • 이상길;김희동;김광헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.152-155
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    • 2002
  • During normal operation, partial discharge(PD) tests were performed using turbine generator analyzer(TGA) in high voltage motor. Epoxy-mica couplers are installed at motor terminal and analyzed PD signal using TGA. #A motor stator insulation is good because small partial discharges are detected PD pattern show that PD occurs in insulation. PD of #B motor is larger than that of #A motor and PD pattern show that positive PD larger than negative PD. It means that PD occurs between insulation and slot. And A phase PD magnitude of #B motor is large and high compare with any other phase. Therefore wedge, core and slot of #B motor need to check and repair.

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고압전동기 고정자 권선의 운전중 부분방전 분석 (Analysis of On-Line Partial Discharge in High Voltage Motor Stator Windings)

  • 이상길;김희동;김광헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.199-202
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    • 2002
  • During normal operation, partial discharge(PD) tests were performed using turbine generator analyzer(TGA) in high voltage motor. Epoxy-mica couplers are installed at motor terminal and analyzed PD signal using TGA. #A motor stator insulation is good because small partial discharges are detected. PD pattern show that PD occurs in insulation. PD of #B motor is larger than that of #A motor and PD pattern show that positive PD larger than negative PD. It means that PD occurs between insulation and slot. And A phase PD magnitude of #B motor is large and high compare with any other phase. Therefore wedge, core and slot of #B motor need to check and repair.

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Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

  • Kim, Young-Hoi;Lee, Jong-Hyuk
    • The Journal of Advanced Prosthodontics
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    • 제4권1호
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    • pp.37-42
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    • 2012
  • PURPOSE. The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS. Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Lightpost) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (${\alpha}$= .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS. The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION. The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

단일 이미지 패턴을 이용한 다수의 전력설비 데이터를 증강하기 위한 패턴 배열화 기법 설계 (Design of Pattern Array Method for Multi Data Augmentation of Power Equipment uisng Single Image Pattern)

  • 김석수
    • 융합정보논문지
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    • 제10권11호
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    • pp.1-8
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    • 2020
  • 전력 소비량이 극대화 되면서 개인 전력 중개사업자 및 전력 생산설비의 증가에 따라 전력 설비를 유지, 보수하기 위한 현장 설비 담당자들을 위한 증강현실 기반 모니터링 시스템들에 대한 연구가 활발하게 진행되고 있다. 그러나 기존 증강현실 기반 모니터링 시스템들의 경우 외부 환경, 설비의 복잡성, 조명환경에 대한 간섭 등의 문제로 인하여 정확한 패턴 검출이 어려우며, 전력 설비에 대한 다양한 센싱 정보 및 서비스 정보를 하나의 패턴에 매칭하지 못하는 문제가 있다. 이로 인하여 전력 설비의 센서별로 단일 이미지의 패턴을 이용하여 센서 정보를 매칭하기 때문에 모든 정보를 증강하여 제공하기 위해 다수의 이미지 패턴이 필요하다. 본 논문에서는 다수의 특징 패턴들로 구성된 단일 이미지에서 특징 패턴들의 배열조합을 통해 다수의 정보를 매칭하여 제공하는 단일 이미지 패턴 배열화 기법을 제안한다.

활로4징증의 완전한 교정술에 있어서 경심방-경폐동맥교정술과 경심교정술의 비교 (Comparison of Tranatrial-transpulmonary and Transventricular Repair of Tetralogy of Fallot)

  • 김덕실
    • Journal of Chest Surgery
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    • 제27권3호
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    • pp.202-208
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    • 1994
  • We reviewed 30 patients with tetralogy of Fallot who had underwent transannular patch reconstruction of the right ventricular outflow tract from January 1990 to May 1993. The patients were divided into two groups according to the approaching pattern for the corrective surgery: 12 patients[aged 11 months to 4 years; mean age, 2.3 years] in transatrial group who were repaired by transatrial-transpulmonary approach; 18 patients[aged 13 months to 6 years; mean age, 3.2 years] in transventricular group who were repaired by transventricular approach. The incidence of postoperative right bundle branch block was not statistically different between two groups. With follow up from 3 months to 32 months after operation, none in transatrial group revealed a remnant RVOT stenosis over 50mmHg or tricuspid regurgitation more than grade II with 2D-echocardiography, but two cases[7.7%] in transventricular group revealed these complications. Early postoperative death was 4 cases[13.3%] which all belonged to transventricular group. In conclusion successful repair of tetralogy of Fallot can be accomplished in most patients by transatrial-transpulmonary approach and we can anticipate better results by this approach in terms of postoperative right ventricular function and arrhythmia than conventional transventricular approach.

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