• 제목/요약/키워드: Percentile Change-point

검색결과 6건 처리시간 0.019초

백분위수 변화점을 고려한 NHPP 소프트웨어 신뢰성장모형에 관한 연구 (The Study for NHPP Software Reliability Growth Model of Percentile Change-point)

  • 김희철;신현철
    • 융합보안논문지
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    • 제8권4호
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    • pp.115-120
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    • 2008
  • 소프트웨어 제품의 정확한 인도시기를 예측하거나 효용성 및 신뢰성을 예측하기 위해서는 소프트웨어 테스팅 과정에서 중요한 요소인 테스트 변화점를 이용하면 보다 효율적인 테스팅 작업을 할 수 있다. 본 논문에서는 기존의 소프트웨어 신뢰성 모형인 지수 모형(Goel-Okumoto 모형)을 적용하여 변화점이 백분위수를 가질 경우를 고려하였다. 고장 간격시간으로 구성된 자료를 이용한 모수추정 방법은 최우추정법과 일반적인 수치해석 방법인 이분법을 사용하여 모수 추정을 실시하고 효율적인 모형 선택은 편차자승합(SSE) 을 적용하여 모형들에 대한 효율적인 모형선택을 시도하였다. 수치적인 예에서는 NTDS 자료를 사용하여 백분위수 변화점을 고려한 결과를 나열하였다.

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여성 승객을 고려한 동승자석 안전벨트의 설계 최적화 (The Optimization of Passenger Seat Belt Design for Female Passenger)

  • 김윤배;김형준;한재녕;김형일;채수원
    • 한국자동차공학회논문집
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    • 제20권4호
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    • pp.10-15
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    • 2012
  • The design of automobile occupant seat belt system has been studied by using MADYMO. Based on the FMVSS 208 (Federal Motor Vehicle Safety Standards 208) and the USNCAP (United States New Car Assessment Program) regulations, seat belt design parameters were chosen for the design improvement to the 5th percentile female dummy: limit force of load limiter, time to fire of shoulder belt, inlet length of shoulder belt, inlet length of lap belt. The design of experiment method was employed to optimize the design parameters of passenger seat belt. Range of injury probability due to the change of H-point position was estimated by the simulation.

여성정책적 측면에서 본 가정노동 지원 (The Needs of Support for Household Labor: Perspective of Women's Policy)

  • 정영금
    • 대한가정학회지
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    • 제36권10호
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    • pp.161-178
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    • 1998
  • This study attemps to identify the factors related to dealing withy work-family conflict of employed women, and to investigate the needs and the methods of support for household labor. Especially, the results of this study aims to be reflected in women's policy from a political point of view. For these purposes, 477 married women those being employed (more than 30 hours per week) and having nuclear family were selected. Statistics were frequencies, means, percentile, and two-way ANOVA. The results were as follows. First, employed mother's housework time is 5 hours 16 minutes on a weekday and 9 hours 32 minutes on Sunday with the exception of market work time. And 84.5% of total housework was performed by housewife. Thus they take chage of work burden(market work and housework), and make a difficulties of cooking and family care. Seconds, the highest needs of support was the change of thought on division of labor, responsibility on housework, and status of women. The next were the needs of the social organization(flex-time, a special holiday for woman workers, home-based work) and the public institution(day-care center, school feeding). Thirds, contributing factors to the needs of support were housewife's age and occupation. So, this two factors were crossed in order to analyze family type by factors.

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기후변화적응을 위한 기상특보 인지도 및 활용도 분석: 건조특보를 중심으로 (Analysis of Utilization and Perception of Special Weather Reports for Climate Change Adaptation: Focus on Dryness Advisory and Warning)

  • 최수진;김은별;정우식;김백조;박종길
    • 한국환경과학회지
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    • 제23권6호
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    • pp.1121-1130
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    • 2014
  • This study aims to find the perception and utilization of the citizen about the dryness watch warning (DWW) among special weather reports. For this we have made up a descriptive questionnaire including the perception, utilization of special weather reports. Using the SPSS 17.0 program, descriptive statistics, t-test, ANOVA and Scheffe test were used to analyze the collected data. The results are as follows; The perception of DWW is measured by 4 point Likert scale and the average is $15.97{\pm}3.70$ (percentile=57.0). This value shows that the awareness level is not that high and according to the occupation, college students show the lowest awareness and housewives show the highest awareness. According to the age, the teens and twenties show the lowest awareness and fifties and sixties show the highest awareness. Although the perception of the teens and college students are rather poor, there were many positive answers that it is necessary to establish the advanced disaster prevention plan according to the questionnaire about the utilization of DWW. Therefore, if we come up with an effective plan to improve the perception than we can expect a large-effect in terms of fire and forest fire prevention. The perception of DWW can be improved by providing weather information and weather related education program on TV or internet which have the high level of preference. Also, it is necessary to provide online and offline program of advertising education and disaster management education through the weather forecast bureau which is the host organization of delivering weather information.

적절한 정맥 재혈류 시점의 판단을 위한 조직산소분압의 유효성 (The Usefulness of Transcutaneous Tissue Oxygen Pressure ($TcpO_2$) for Determination of the Point of Time at Venous Revascularization)

  • 이은상;정종필;박승하;이병일
    • Archives of Plastic Surgery
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    • 제37권5호
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    • pp.547-554
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    • 2010
  • Purpose: The purpose of this study is to delineate the optimal time of venous revascularization for preventing the flap necrosis due to venous occlusion, and to clarify the usefulness of tissue oxygen pressure ($TcpO_2$) in the determination of the point of time for venous revascularization. Methods: Thirty-six, $3{\times}3\;cm$ sized epigastric island flap was elevated in left abdomen of male Sprague-Dawley rat weighing 250 gram. Flaps were randomly assigned to six groups of six flaps according to the duration of venous occlusion with microvascular clamp; 10 minutes in the group I as the control, 60 minutes in the group II, 2 hours in the group III, 3 hours in the group IV, 4 hours in the group V, and 6 hours in the group VI, respectively. Just before removal of clamp after flap was reposed in situ, the ratio of $TcpO_2$ (tissue oxygen pressure) of the island flap to that of right abdomen was calculated in each group, and tissue specimen was harvested from the distal area of the flap for histological evaluation of vascular change. Five days later, survival area of the flap was estimated, and evaluated the correlation between the tissue oxygen pressure and the rate of flap survival. Results: The $TcpO_2$ and the survival rate of flap were decreased proportionally with the duration of venous occlusion. The ratio of the $TcpO_2$ of the flap is decreased abruptly to below sixty percentile compared to the $TcpO_2$ of normal tissue, and the survived area of the flap is decreased to nine-tenth of the designed size after three hours of total venous occlusion. Histologically, the number of congested vessels was increased according to venous occluded time, and proportionally increased after 3-hours of occlusion significantly. Conclusion: There is a close correlation between the $TcpO_2$ and the survival rate of flaps according to the duration of venous occlusion. Therefore, the $TcpO_2$ represents the hemodynamic changes within the flap, and thought to be an alternative effective tool in the flap monitoring for venous revascularization.

복합운동이 과체중 및 비만 남자 초등학생의 대사적지표에 미치는 영향 (Effect of combined exercise on metabolic bio-marker in overweight and obese children)

  • 김현준;김태운;이상엽;신군수;김영주;김수영
    • Clinical and Experimental Pediatrics
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    • 제49권9호
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    • pp.946-951
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    • 2006
  • 목 적 : 본 연구는 복합운동이 비만 아동의 에너지 대사를 긍정적으로 개선시킬 수 있는지를 알아보고자 복합운동 프로그램 12주 동안 아디포넥틴과 비만관련 변수와의 변화를 분석하였다. 방 법 : 일개 초등학교 5학년 남학생 중 체질량지수가 85백분위수 이상인 과체중 및 비만 아동을 대상으로 본 연구를 시행하였다. 대상자들은 12주 동안 걷기운동과 밴드저항운동을 조합한 복합운동프로그램을 시행하였다. 신장, 체중, 체지방량, 공복 혈당, 인슐린 및 아디포넥틴 측정은 복합운동프로그램 시작 전 및 프로그램 시행 1주, 4주, 12주째에 측정하였다. 인슐린 저항성 및 민감도는 HOMA 지수와 QUICKI 지수를 사용하였다. 결 과 : 아디포넥틴은 운동 4주 후에는 유의하게 감소하였으며, 이후 증가하는 양상을 보여 운동 12주 후에는 운동 전과 유사한 수준으로 운동 프로그램이 지속됨에 따라 증가하는 경향을 보였다. 체중, 체질량지수 및 인슐린 저항성은 복합운동 1주, 4주, 12주 후에 운동군이 대조군에 비해 유의한 감소를 보였다. 체지방률은 복합운동 12주에 운동군에서 대조군에 비해 유의한 감소가 관찰되었다. 운동이 진행됨에 따라 체중 및 체질량지수 변화량과 인슐린 변화량 간에는 유의한 관련성이 있었으며, 아디 포넥틴 변화량과 인슐린 변화량 간에는 유의한 관련성이 없었다. 결 론 : 본 연구 결과 인슐린저항성은 복합운동 1주 후부터 개선되기 시작하였다. 아디포넥틴은 운동 초기에 감소하다 특정시기 이상의 지속적인 운동에서 증가하는 경향을 보였다. 따라서 운동이 아디포넥틴 농도 변화에 영향을 미친다는 것을 제시할 수 있지만, 장기간의 지속적인 운동에 따른 아디포넥틴 농도의 변화에 대해서는 후속 연구가 이루어져야 할 것이다.