• 제목/요약/키워드: stepwise analysis

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한국형 기동무기체계 양산비 비용추정관계식 개발에 관한 연구 (A Study on Developing a CER Using Production Cost Data in Korean Maneuver Weapon System)

  • 이두현;김각규
    • 한국경영과학회지
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    • 제39권3호
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    • pp.51-61
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    • 2014
  • In this paper, we deal with developing a cost estimation relationships (CER) for Korean maneuverable weapons systems using historical production cost. To develop the CER, we collected the historical data of the production cost of four tanks and five armored vehicles. We also analyzed the Required Operational Capability (ROC) of the weapons systems and chose cost drivers that can compare operational capabilities of the weapons systems We used Forward selection, Backward selection, Stepwise Regression and $R^2$ selection as the cost drivers which have the greatest influence with the dependent variables. And we used Principle Component Regression, Robust Regression and Weighted Regression to deal with multicollinearity and outlier among the data to develop a more appropriate CER. As a result, we were able to develop a production cost CER for Korean maneuverable weapons systems that have the lowest cost errors. Thus, this research is meaningful in terms of developing a CER based on Korean original cost data without foreign data and these methods will contribute to developing a Korean cost analysis program in the future.

기혼여성이 지각한 가정생활상의 Stress 수준 및 관련 변인 고찰 (A Study on the Stress Level Percepted by the married Women during Family Life and it's Related Variables.)

  • 김경아;이정우
    • 가정과삶의질연구
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    • 제8권2호
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    • pp.101-118
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    • 1990
  • The purpose of this study is to examine the stress level and factors percepted by the married women during family life, and to identify the related variables influencing on stress level. For this purpose, questionnaires were distributed to the 650 married women who have been living in seoul. Among them 463 data were selected. For data analysis, the statistical method such as the factor analysis frequency distribution percentile , t-test, ANOVA, Duncan's Multiple Range Test and Stepwise Regression Analysis were used. the major findings were summarized as follows; 1) The general tendancy of the stress level percepted by the married women during family life was relatively low. 2) The household background variables(age, level of education, income, type of family, number of children, status of employment ) have turned out to be significant on the stress level of married women except family type. 3) All the social-psychological variables(socio-economic status, communication interaction, resources perception, psychological satisfaction) showed significant differences according to the stress level percepted by the married women during family life. 4) The level of work identity was the important factor on the stress level percepted by the married women during family life. 5) In Stepwise Multiple Regression Analysis, the married women's stress level during family life was greatly influenced by variables such as the resource perception and the psychological satisfaction.

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Relationship between Aiming Patterns and Scores in Archery Shooting

  • Quan, ChengHao;Lee, Sangmin
    • 한국운동역학회지
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    • 제26권4호
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    • pp.353-360
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    • 2016
  • Objective: The aim of this study was to investigate the relationship between aiming patterns and scores in archery shooting. Method: Four (N = 4) elementary-level archers from middle school participated in this study. Aiming pattern was defined by averaged acceleration data measured from accelerometers attached on the body during the aiming phase in archery shooting. Stepwise multiple regression analysis was used to test whether a model incorporating aiming patterns from all nine accelerometers could predict the scores. In order to extract period of interest (POI) data from raw data, a Dynamic Time Warping (DTW)-based extraction method was presented. Results: Regression models for all four subjects are conducted with different significance levels and variables. The significance levels of the regression models are 0.12%, 1.61%, 0.55%, and 0.4% respectively; the $R^2$ of the regression models is 64.04%, 27.93%, 72.02%, and 45.62% respectively; and the maximum significance levels of parameters in the regression models are 1.26%, 4.58%, 5.1%, and 4.98% respectively. Conclusion: Our results indicated that the relationship between aiming patterns and scores was described by a regression model. Analysis of the significance levels, variables, and parameters of the regression model showed that our approach - regression analysis with DTW - is an effective way to raise scores in archery shooting.

H형강 교량의 성능개선을 위한 다단계 온도프리스트레싱 효과 분석 (Effects of Multi-stepwise TPSM on Improving the Behavior of H-beam bridge)

  • 안진희;김준환;정치영;김상효
    • 한국강구조학회 논문집
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    • 제19권5호
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    • pp.527-537
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    • 2007
  • H형강 교량은 공장에서 압연 제작한 H형강을 주형과 가로보로 사용함에 따라 품질 및 관리가 용이하고 공장제작으로 현장작업 및 공사기간의 단축과 보강재의 설치량이 적은 단순하고 경제적인 교량형식이다. 본 연구는 기존 H형강 교량의 지간 및 단면 효율 개선을 위한 방법으로 다단계 온도프리스트레싱(Multi-Stepwise TPSM) 공법을 H형강 교량에 적용하여 도입효과 및 적용지간을 분석하였다. 구조해석결과 H형강교의 다단계 온도프리스트레싱 효과는 H-$900{\times}300$형강을 이용한 30m 5주형 H형강교량을 기준으로 기존 플레이트 거더 교량의 높이를 50.7~55.1%, 중량을 24.1~26.2% 수준으로 감소시킬 수 있는 것으로 평가되었다. 또한 7주형 H형강교량의 주형수를 5주형으로 감소시켜 경제적인 교량건설이 가능한 것으로 나타나 온도프리스트레싱이 도입된 H형강 교량은 기존 H형강과 비교하여 중소지간용 교량으로 충분한 경제성을 가질 수 있을 것으로 판단된다.

활성오니공법에 있어서 수온이 처리효율에 미치는 영향에 관한 분석 -청계천 하수종말처리장에 대하여- (Analysis of Temperature Effect on Activated Sludge Process at Cheong-Gye Cheon Sewage Treatment Plant)

  • 이은경
    • 한국환경보건학회지
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    • 제7권1호
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    • pp.9-20
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    • 1981
  • This study was performed to determine the correlationship between temperature and overall removals of BOD, SS and to demonstrate the effect of temperature on treatment performance. These data for a period from February 1, 1977 to January 31, 1980 were obtained from the Cheong-Gye Cheon Sewage Treatment plant. The results of correlation and stepwise multiple regression analysis were as follows. 1) Secondary effluent BOD and SS showed negative correlationship with water temperature, with correlation coefficient of -0.1710, and -0.1654 respectively. 2) Correlation coefficient of BOD, SS removal rate and water temperature were 0.1823 and 0.0429 respectively. 3) Regresion equation for estimate of BOD removal rate was as follows $\widehat{Y}_1$ (BOD removal rate)=63.9994+0.5442X(water temperature). And BOD removal rate showed non significant change according to the water temperature. 4) Regression equation for estimate of SS removal rate was as follows $\widehat{Y}_2$ (SS removal rate)=61.6881+0.1514X(Water temperature). And SS removal rate showed non significant change according to the water temperature. 5) According to the Stepwise Multiple Regression analysis, water temperature ranked second order in the BOD removal rate estimation and the equation was as follows $\widehat{Y}_1$ (BOD removal rate)=69.7398+0.2665 $X_1$ (Primary effluent BOD)+0.3562 $X_2$ (Water temperature)-0.0122 $X_3(Flow)+4413.271X_4$ (Organic Loading).

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The Effect of Vitamin D and Calcium on Cognitive Function and Depression in the Elderly Living in a City

  • Lee, Yu-Jin;Kim, Yun-Su
    • 지역사회간호학회지
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    • 제28권3호
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    • pp.251-259
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    • 2017
  • Purpose: This study aims to examine the influence of vitamin D and calcium on depression and cognitive function of the elderly living alone in a city. Methods: The participants were registered in eight senior centers in S city and they had lived alone. Data were collected between November 28, 2014 and March 7, 2015. A total of 155 people participated in data collection to measure the serum vitamin D, the serum calcium, depression, and cognitive function. The data were analyzed with t-test, ANOVA, Pearson's correlation and multiple regression analysis. Results: There were significant differences in depression according to gender and perceptions of health status. Depression correlated significantly with the serum calcium and perceptions of health status, and a stepwise regression analysis showed that the perceptions of health status were significant. There were significant differences in cognitive function according to education level and age. Cognitive function correlated significantly with the serum vitamin D and a stepwise regression analysis showed that education level and age were significant. Conclusion: Consequently, elderly people with poor perceptions of their health status need a depressive intervention program and those with a higher age and lower level of education need a cognitive function intervention program.

신흥 기술의 단계적 벤치마킹을 위한 SOM, DEA와 AHP 방법의 순차 활용 (Sequential use of SOM, DEA and AHP method for the stepwise benchmarking of emerging technology)

  • Yu, Peng;Lee, Jang Hee
    • 지식경영연구
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    • 제13권5호
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    • pp.43-64
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    • 2012
  • Emerging technologies have significant implications in establishing competitive advantages and are characterized by continuous rapid development. Efficient benchmarking is more and more important in the development of emerging technologies. Similar input level and importance are two necessary criteria need to be considered for emerging technology's benchmarking. In this study, we proposed a sequential use of self-organizing map(SOM), data envelopment analysis(DEA) and analytical hierarchy process(AHP) method for the stepwise benchmarking of emerging technology. The proposed method uses two-level SOM to cluster the emerging technologies with similar required input levels together, then, in each cluster, uses DEA-BCC model to evaluate the efficiencies of the emerging technologies and do tier analysis to form tiers. On each tier, AHP rating method is used to calculate each emerging technology's importance priority. The optimal benchmarking path of each cluster is established by connecting the emerging technologies with the highest importance priority. In order to validate the proposed method, we apply it to a case of biotechnology. The result shows the proposed method can overcome difficulties in benchmarking, select suitable benchmarking targets and make the benchmarking process more efficient and reasonable.

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회귀분석에 기초한 균등화 방법에 관한 연구 (A study on equating method based on regression analysis)

  • 조장식
    • Journal of the Korean Data and Information Science Society
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    • 제21권3호
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    • pp.513-521
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    • 2010
  • 대부분의 대학들은 교수업적평가를 위해 강의평가제도를 실시하고 있다. 그러나 강의평가의 결과는 강좌규모, 강의형태, 개설학년, 이수구분, 평균평점 등과 같은 개설강좌의 특성에 많은 영향을 받게 된다. 따라서 이러한 각 강좌특성들이 강의평가 결과에 영향을 미치는 효과를 제거하지 않는다면, 담당교수가 강의평가 결과에 대한 공정성과 객관성을 신뢰할 수 없게 만들 정도로 심각한 편의를 갖게 된다. 따라서 강의평가의 공정성을 위해 강좌특성에 따른 편의를 제거하기 위한 사후조정된 점수가 요구된다. 따라서 본 연구에서는 단계적 변수선택법에 의한 회귀분석을 이용하여 강의평가 결과에 대한 균등화 방법을 이용하여 사후조정된 점수를 계산하는 방법을 제안한다. 그리고 제안된 방법은 기존의 방법과 비교를 하였다.

청소년의 스트레스, 사회적지지, 건강행위와의 관계 (This Study Investigated the Relationship of Stress Levels, Social Support, and Health Behaviors in the Adolescent Population)

  • 김영아
    • Child Health Nursing Research
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    • 제7권2호
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    • pp.203-212
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    • 2001
  • The subjects were 349 high school boys and girls who were 10th and 11th graders in Seoul, Korea. Statistical analysis included percentages, means, Pearson correlation coefficient, ANOVA, t-test, and stepwise multiple regression analysis. As a result, there were positive correlations between social support, stress reduction and increases in health behavior. Stepwise multiple regression analysis of social support, stress, and adolescents health behavior showed that social support explained 26.3% of the variance in health behavior, The more social support subjects experienced more health behavior level and the less the correlated stress level. In the area of demographic attributes, gender, height, weight, grade level, socioeconomic level of the parents, and stress were significantly correlated, grade levels, religion, socioeconomic level of parents and social support. sibling order, religion, socioeconomic level of the parents, parents education, occupation of father. and health behavior were statistically significant The findings indicated stress was a negative factor in health behavior, and social support was a positive factor in reducing stress and promoting health behavior. To reduce adolescents stress and to promote health behavior, we should endeavor to develop realistic social support programs.

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A Study on Transmission System Expansion Planning using Fuzzy Branch and Bound Method

  • Park, Jaeseok;Sungrok Kang;Kim, Hongsik;Seungpil Moon;Lee, Soonyoung;Roy Billinton
    • KIEE International Transactions on Power Engineering
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    • 제2A권3호
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    • pp.121-128
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    • 2002
  • This study proposes a new method for transmission system expansion planning using fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual system. A branch and bound method which includes the network flow method and the maximum flow - minimum cut set theorem has been used in order to carry out the stepwise cost characteristics analysis. Uncertainties of the permissibility of the construction cost and the lenient reserve rate and load forecasting of expansion planning have been included and also processed using the fuzzy set theory in this study. In order to carry out the latter analysis, the solving procedure is illustrated in detail by the branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on the 21- bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in the future.