• 제목/요약/키워드: screening conditions

검색결과 602건 처리시간 0.023초

접합 온도를 고려한 TO-CAN 레이저 다이오드의 Screening 조건 연구 (Study on junction temperature characteristics of TO-CAN laser diode for optimized screening tests)

  • 이동수
    • 조명전기설비학회논문지
    • /
    • 제16권6호
    • /
    • pp.126-129
    • /
    • 2002
  • 레이저 다이오드의 동작 수명을 예측하고 안정화된 성능과 신뢰도를 만족하기 위해서는 검증된 시스템으로 광부품의 신뢰성 테스트를 수행하는 것이 중요하다. 본 연구에서는 온도와 인가 전류에 따른 접합 온도(junction temperature) 특성을 관찰하여 실제 주위 온도 ( $T_{A}$)와 광소자의 온도( $T_{j}$) 차이를 이론 및 실험 적으로 도출하였고, 이를 토대로 정밀한 burn-in 테스트를 위한 screening 조건을 설정해 제시하였다.하였다.

발전소용 분산제어시스템의 스크리닝 시험에 관한 고찰 (An Investigation of ESS(Environmental Stress Screening) Test of the DCS to be used for a thermal power plant.)

  • 이주현;마복렬;오영일;정문식
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1999년도 하계학술대회 논문집 B
    • /
    • pp.871-873
    • /
    • 1999
  • According to the reports about the failure mode analysis of modules and systems, It is said that there are many early failure of system. To remove latent defects which causes early failures like that, It is necessary that screening test is performed. ESS is often used fur screening electronic equipments, and is proposed by the most powerful tool for removing latent defects of electronic equipments. [1][2] In this report, the procedure of the environmental stress screening which uses the temperature cycling stress is proposed. It is considered about environmental conditions of distributed control system(DCS) to be tested, design specifications of the system, recommended conditions of relative IEC-STD and applied conditions of similar company. ESS test was applied at the DCS to be installed in power plant. As the results of analyzing discovered problems. It was found that almost latent defects of electronic control systems was discovered early.

  • PDF

A Simple Method of Seedling Screening for Drought Tolerance in Soybean

  • Kim, Young-Jin;S. Shanmungasundaram;Yun, Song-Joong;Park, Ho-Ki;Park, Moon-Soo
    • 한국작물학회지
    • /
    • 제46권4호
    • /
    • pp.284-288
    • /
    • 2001
  • Water deficit is a serious constraint to soybean [Glycine max L. (Merr.)] production in rainfed regions of Asia, Africa, and America. This study was conducted to develop a simple and effective screening method for drought tolerance in soybean. Fifteen soybean cultivars, eight identified to be drought-tolerant and seven drought-sensitive in previous studies, were used for the evaluation of drought tolerance under the new screening conditions. The seedling screening method was consisted of a treatment in a PEG solution and drought treatment in parafilm-layered pots. 5-day-old seedlings were treated in a 18% PEG solution for 4 days and their wilting and hypocotyl browning were recorded. Three seedlings grown in a parafilm-layered pot containing peat moss were drought-stressed by withholding water from the third day after seedling emergence, and root and seedling growth were examined. Degree of drought tolerance were rated based on seedling vigor in the PEG solution and drought-stressed parafilm-layered pots, and also on the penetration ability of roots through parafilm layer. Most of seedlings of the drought-tolerant cultivars showed higher vigour and root penetration than those of the drought-sensitive cultivars under the new screening conditions. Our results indicate that the new method can be used as a simple and effective screening procedure for drought tolerance in soybean breeding programs.

  • PDF

Free Spanning of Offshore Pipelines by DNV

  • CHOI HAN SUK
    • 한국해양공학회지
    • /
    • 제19권2호
    • /
    • pp.47-52
    • /
    • 2005
  • This paper introduces a procedure for free span and fatigue analysis of offshore pipelines per DNV-RP-F105, 2002. The new method includes the axial force and deflection load in pipelines. The screening criteria were established to calculate the allowable span lengths in the new design codes. The screening criteria allows a certain amount of vortex-induced vibration due to wave and current loading. However, the induced pipe stresses are very small and usually below the limit stresess of typical S-N curves. In contrast, the conventional criteria did not allow any vortex-induced vibration in the free span of pipelines. Thus, the screening criteria yields reduced allowable span lengths. A simplified procedure was established to calculate the fatigue damage due to long-term current distribution. The long-term current statistics was assumed with a 3-parameter Weibull distribution. The fatigue damage was estimated for the span lengths obtained from the screening criteria for various conditions. Sample calculations show the effect of axial force for various boundary conditions. Comparisons with conventional criteria are included.

A Case-Based New Financial Product Screening System

  • Lee, Hoon-Young
    • 한국경영과학회지
    • /
    • 제19권3호
    • /
    • pp.151-167
    • /
    • 1994
  • Initial screening is one of the most important and difficult processes in new product development. Many new product screening models have been developed in management and marketing. However practical applications of these models have been limited in part due to their complexity and inflexibility, and in part due to their excessive data requirements. Thus simple judgment models have been popular in practice. However, these models suffer from inaccuracy and inconsistency originating form human cognitive limitations. In light of the problem swith traditional screening methods, we propose a new approach for screening based on managers' past experience and intuitive judgments-screening by analogy, and develop a computerized case-based system for screening new financial service concepts. Using the system, managers can predict the potential performance of a new product concept based on the performance of past products that are similar to it in terms of product characteristics, firm's resources, and market conditions. Based on this prediction, managers make a screening decision.

  • PDF

Improving Participation in Colorectal Cancer Screening: a Randomised Controlled Trial of Sequential Offers of Faecal then Blood Based Non-Invasive Tests

  • Symonds, Erin L;Pedersen, Susanne;Cole, Stephen R;Massolino, Joseph;Byrne, Daniel;Guy, John;Backhouse, Patricia;Fraser, Robert J;LaPointe, Lawrence;Young, Graeme P
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제16권18호
    • /
    • pp.8455-8460
    • /
    • 2016
  • Background: Poor participation rates are often observed in colorectal cancer (CRC) screening programs utilising faecal occult blood tests. This may be from dislike of faecal sampling, or having benign bleeding conditions that can interfere with test results. These barriers may be circumvented by offering a blood-based DNA test for screening. The aim was to determine if program participation could be increased by offering a blood test following faecal immunochemical test (FIT) non-participation. Materials and Methods: People were invited into a CRC screening study through their General Practice and randomised into control or intervention (n=600/group). Both groups were mailed a FIT (matching conventional screening programs). Participation was defined as FIT completion within 12wk. Intervention group non-participants were offered a screening blood test (methylated BCAT1/IKZF1). Overall participation was compared between the groups. Results: After 12wk, FIT participation was 82% and 81% in the control and intervention groups. In the intervention 96 FIT nonparticipants were offered the blood test - 22 completed this test and 19 completed the FIT instead. Total screening in the intervention group was greater than the control (88% vs 82%, p<0.01). Of 12 invitees who indicated that FIT was inappropriate for them (mainly due to bleeding conditions), 10 completed the blood test (83%). Conclusions: Offering a blood test to FIT non-participants increased overall screening participation compared to a conventional FIT program. Blood test participation was particularly high in invitees who considered FIT to be inappropriate for them. A blood test may be a useful adjunct test within a FIT program.

근로자 일반건강진단에 대한 태도 조사연구 -건강진단기관과 대상 사업체를 중심으로- (A Study on the Attitude Toward the Periodic Health Screening for Workers in Korea -Attitude of Personnels in Health Screening Institutions and Enterprises-)

  • 서동윤;송동빈
    • Journal of Preventive Medicine and Public Health
    • /
    • 제20권2호
    • /
    • pp.270-279
    • /
    • 1987
  • In all enterprises of Korea employing workers more than five, employeers have a duty of conducting a periodic health screening for improvement and maintaining healthful living and working conditions of employees. The health screening is performed annually in line workers and biennially in table workers under the supervision of the government. But there are some argument to the health screening programme in view of effectiveness, efficiency, reliability and etc. In order to obtain basic reference materials for increasing the efficiency of peridoic health screening programme for workers and understand the attitude of health screening institutions and enterprises toward the periodic health screening, mail questionnaire survey was conducted in July 1987. The questionnaire sent to 950 health screening institutions. and 700 enterprises in whole land but they were returned from 254 health istitutions and 187 enterprises, which were analyzed. The results were as follows: 1) The attitude of the respondents toward the necessity and benefit of the periodic health screening was showed highly positive responses in both of screening institutions and enterprises, and it was more positive in screening institutions. The attitude toward the affirmative and the contentment was showed less positive than that of the necessity and benefit. 2) The respondent recognized may problems on regard to the screening programme. The health screening institutions lie in the state of competition with other institutions for undertaking the screening programme. 3) One of major complaints from enterprises was the lack of sincerity in performing the screening programme. They wanted more practical and reliable health screening examination rather than showy one. 4) Health screening institutions and enterprises showed some mutual contradictions in the matter of screening fee, and so the screening fee should be adjusted to the appropriate cost.

  • PDF

Screening panoramic radiographs in a group of patients visiting a Health Promotion Center

  • Lee Jae-Seo;Kang Byung-Cheol
    • Imaging Science in Dentistry
    • /
    • 제35권4호
    • /
    • pp.199-202
    • /
    • 2005
  • Purpose : To report the incidence of radiological findings from screening panoramic radiographs and verify the validity of the panoramic radiography for screening purposes. Materials and Methods : Six thousand one hundred and sixty panoramic radiographs taken from the patients visiting the Health Promotion Center of CNUH were selected for this retrospective study. Panoramic radiographs were examined into the following pathologic conditions : the presence of periodontal bone loss, dental caries, periapical radiolucencies, retained roots, impacted supernumerary teeth, impacted third molars, odontoma, cystic lesions other than radicular cyst, sialoliths, and mixed radiolucent-radiopaque lesions. Number of pathologic conditions and Prevalence values were recorded. Results: The prevalences of pathologic conditions were $72.9\%$ of periodontal bone loss, $32.2\%$ of dental caries, $11.9\%$ of periapical radiolucencies, $10.8\%$ of retained roots, $0.4\%$ of root fracture, $1.0\%$ of impacted supernumerary teeth, $1.0\%$ of impacted third molars, $0.06\%$ of odontoma, $0.08\%$ of cystic lesion other than radicular cyst, $0.2\%$ of prolonged retention of deciduous tooth, $0.1\%$ of sialolith, and $0.04\%$ of mixed radiopaque and radiolucent lesion. Conclusion : Although the panoramic radiograph should not be used to replace intraoral radiographic and clinical examinations, this study showed that many dental pathologic conditions could be detected on panoramic radiographs. The panoramic radiograph might serve as a diagnostic aid in dental health evaluation programs.

  • PDF

복합방진벽에 의한 Rayleigh파의 차단 (Screening of Rayleigh Waves by Composite Barriers)

  • 이종세
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
    • /
    • pp.133-140
    • /
    • 1997
  • Based on the Green's function technique, an analytical approach is developed to examine the surface wave screening effectiveness of composite wave barriers. The composite barrier consists of a high velocity layer sandwiched between two thin layers of low shear velocity materials. The high velocity layer is represented by differential matrix operators which relate the wave fields on each side of the layer. The low velocity layers are modeled by non-rigid contact conditions which allow partial sliding at the interfaces. Screening ratio of barriers with various combination of material, geometric, and non-rigidness parameters are compared and discussed in some detail.

  • PDF

고효율 효소를 분비하는 균주의 선발 및 신문고지의 효소탈묵 특성(제2보) -Cellulase와 Xylanase를 생산하는 Fungi의 분리 및 선발- (Screening of Microorganisms Secreted High Efficient Enzymes and Properties of Enzymatic Deinking for Old Newsprint(II) - Isolation and screening of fungi producing cellulase and xylanase-)

  • 박성철;강진하;이양수
    • 펄프종이기술
    • /
    • 제36권3호
    • /
    • pp.9-14
    • /
    • 2004
  • The useful fungi which secret extracellular enzymes was selected for deinking agent of old newsprint. Five fungal strains were isolated from a paper mill soil ground. The CMCase, FPase and xylanase activities of fungi on the liquid culture were investigated at optimal growth conditions. The results of this study were as follow: The optimal pH and temperature for culture growth were 4~8 and 27~$35^{\circ}C$, respectively. For screening of extracellular enzymes at optimal culture conditions the optimal culture period were less than 6-7 days. Fusarium pallidoroseum and Aspergiilus niger which shows relatively higher CMCase, FPase and xylanase activities than the other species were selected for further enzymatic deinking research.