• Title/Summary/Keyword: Percentile Change-point

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

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • Convergence Security Journal
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    • v.8 no.4
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    • pp.115-120
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    • 2008
  • Accurate predictions of software release times, and estimation of the reliability and availability of a software product require quantification of a critical element of the software testing process: Change-point problem. In this paper, exponential (Goel-Okumoto) model was reviewed, proposes the percentile change-point problem, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics, for the sake of efficient model, was employed. Using NTDS data, The numerical example of percentilechange-point problemi s presented.

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

  • Kim, Yun-Bae;Kim, Hyung-Jun;Han, Jae-Nyung;Kim, Hyung-Il;Chae, Soo-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.4
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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.

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

  • 정영금
    • Journal of the Korean Home Economics Association
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    • v.36 no.10
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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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Analysis of Utilization and Perception of Special Weather Reports for Climate Change Adaptation: Focus on Dryness Advisory and Warning (기후변화적응을 위한 기상특보 인지도 및 활용도 분석: 건조특보를 중심으로)

  • Choi, Su-Jin;Kim, Eun-Byul;Jung, Woo-Sik;Kim, Baek-Jo;Park, Jong-Kil
    • Journal of Environmental Science International
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    • v.23 no.6
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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.

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

  • Lee, Eun-Sang;Choung, Jong-Pil;Park, Seung-Ha;Lee, Byung-Il
    • Archives of Plastic Surgery
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    • v.37 no.5
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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.

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

  • Kim, Hyun-Jun;Kim, Tae-Un;Lee, Sangyeoup;Shin, Goon-Soo;Kim, Young-Joo;Kim, Su-Yung
    • Clinical and Experimental Pediatrics
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    • v.49 no.9
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    • pp.946-951
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    • 2006
  • Purpose : The purpose of this study was to demonstrate the effectiveness of combined exercise for 12 weeks on the adiponectin and obesity related variables in overweight and obese children. Methods : Eighteen children in 5th grade in a certain elementary school in Busan were recruited. They were all overweight or obese children(more than 85 percentile in body mass index). Nine children in the experimental group were given exercises consisting of walking and band resistant training for 12 weeks. Auxological data(including height, weight and body fat mass) and laboratory data (fasting blood sugar, insulin, adiponectin) were checked at baseline and at the 1 week, and at the 4 weeks and 12 weeks stages of their exercise program. Insulin resistance and sensitivity were evaluated indirectly using HOMA index and QUICKI index. Results : Adiponectin gradually decreased until the 4 weeks point and gradually increased thereafter to the starting level at the 12 weeks stage. Body weight, body mass index(BMI) and HOMA index significantly decreased more at the 1 week, 4 weeks, and 12 weeks stages in the experimental group than in the control group. Body fat mass significantly decreased at 12 weeks. The change of insulin was significantly correlated with changes of body weight and BMI. But there was no correlation between changes of adiponectin and changes of insulin. Conclusion : Exercise seems to effect the adiponectin concentration. And it might be assumed that exercise increases the adiponectin concentration if it is continued for long time(may be more than 12 weeks). More studies may be necessary to draw that conclusion.