• 제목/요약/키워드: Study variable

검색결과 13,619건 처리시간 0.042초

건설장비의 탄소배출량 산정에 미치는 유휴시간의 영향 분석 (Analysis of the Impact of Idle Time on the Estimation of Carbon Emissions of Construction Equipment)

  • 오상민;이동윤;강고운;조훈희;강경인
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.193-194
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    • 2017
  • Effect of variable factors on carbon emissions in construction industry is hard to analysis. Therefore this study analyzies effect of variable factors on carbon emissions. This study shows importance of variable factors and emphasizes need of estimation of carbon emissions considering variable factors.

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Pre-Adjustment of Incomplete Group Variable via K-Means Clustering

  • Hwang, S.Y.;Hahn, H.E.
    • Journal of the Korean Data and Information Science Society
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    • 제15권3호
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    • pp.555-563
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    • 2004
  • In classification and discrimination, we often face with incomplete group variable arising typically from many missing values and/or incredible cases. This paper suggests the use of K-means clustering for pre-adjusting incompleteness and in turn classification based on generalized statistical distance is performed. For illustrating the proposed procedure, simulation study is conducted comparatively with CART in data mining and traditional techniques which are ignoring incompleteness of group variable. Simulation study manifests that our methodology out-performs.

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결혼이주여성의 아동학대 발생위험성에 영향을 미치는 요인 -양육스트레스, 문화적응스트레스, 사회적지지의 구조적 관계- (Social Support, Acculturative Stress, and Parenting Stress as Factors Influencing Child Abuse Among Married Immigrant Women in Korea)

  • 박명숙;이재경
    • 한국사회복지학
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    • 제66권2호
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    • pp.179-202
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    • 2014
  • 본 연구는 결혼이주여성의 아동학대 발생위험에 영향을 미치는 요인으로 양육스트레스, 문화적응스트레스, 사회적지지의 구조적관계를 검증하는데 목적이 있다. 선행연구들을 바탕으로 가설모형을 설정한 후, 전국을 표본으로 결혼이주여성 195명에 대한 설문결과를 분석하였다. 분석결과 아동학대에 직접효과를 갖는 변수는 양육스트레스였고, 문화적응스트레스는 양육스트레스를 매개로 간접효과를 갖는 것으로 나타났다. 이와 함께 사회적지지는 아동학대에 영향을 미치는 양육스트레스에 대해 문화적응스트레스를 매개로 간접효과를 갖는 것으로 나타났다. 사회적지지는 아동학대에 직접적인 영향을 미치지 않았으나, 아동학대에 영향을 미치는 위험요인들을 상쇄시키는 보호요인으로 기능하였다. 이와 같은 연구결과에 근거하여 사회복지에 대한 실천적, 정책적 함의를 제안하였다.

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스마트폰을 대상으로 한 휴리스틱 및 프로스펙트 효과 분석: 프레이밍, 보유효과 및 조절초점 이론을 중심으로 (Analysis of the Heuristic Theory and the Prospect Theory for Smartphones: Focusing on Framing, Endowment Effect and Regulatory Focus Theory)

  • 김순홍
    • 유통과학연구
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    • 제14권12호
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    • pp.99-105
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    • 2016
  • Purpose - In the present study, it has become the most important necessity in our daily lives that consumers' psychological factors affect the use of smartphones, and it has been analyzed through behavioral economic approaches. In this respect, the present study is intended to apply the heuristic theory and the prospect theory among behavioral economics theories to examine how psychological factors affect consumers' product selection. Research design, data, and methodology - In the present study, using smartphone repurchase as a dependent variable, whether regulatory focus effects have interaction effects on behavioral economic theories and behavioral economic effects such as possession (ownership) effects, framing effects, and brand recollection. As an analysis method, questionnaire surveys conducted with university students in Incheon were examined through Two-Way ANOVAs using the SPSS23 package. Results - The analysis from the results are as follows. Using smartphone repurchase as a dependent variable, the main effects and interaction effects on two variables; satisfaction difference with product functions and positive framing variable were statistically significant. Using repurchase as a dependent variable was statistically significant, there was no interaction effect between the two variables; satisfaction difference with product functions and the difference of brands in possession. Using smartphone repurchase as a dependent variable, interaction effects on two variables; satisfaction difference with product functions and the lengths of product possession periods were not statistically significant. The results from the analyses of interaction effects of brand recollection and brands type were statistically significant in possession using repurchase as a dependent variable. The results from the analyses of the main effect of the brands type were statistically significant in possession using repurchase as a dependent variable. Conclusions - The implication of the present study is that it suggests the factors that became important for customers' smartphone purchase following the change in the meaning of smartphones from practical products in the past to hedonic products. Limitations of the present study are first, the study subjects are limited to students and the number of copies in questionnaires is only approximately 130, which is insufficient, so that the present study is not sufficient as a study for entire smartphone users.

의사결정나무에서 분리 변수 선택에 관한 연구 (A Study on Selection of Split Variable in Constructing Classification Tree)

  • 정성석;김순영;임한필
    • 응용통계연구
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    • 제17권2호
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    • pp.347-357
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    • 2004
  • 의사결정나무에서 분리 변수를 선택하는 것은 매우 중요한 일이다. C4.5는 변수 선택에 있어 연속형 변수로의 변수 선택 편의가 심각하고, QUEST는 연속형 변수와 관련해서 정규성 가정이 위반될 경우 변수 선택력이 떨어진다. 본 논문에서는 통계적 로버스트 검정 알고리즘을 제안하고, 모의 실험을 통하여 C4.5, QUEST그러고 제안된 알고리즘의 효율성을 비교하였다. 실험 결과 제안된 알고리즘이 변수 선택 편의와 변수 선택력 측면에서 로버스트함을 알 수 있었다.

자동차 엔진용 2단 가변밸브 기구의 스위칭 시스템 동적 거동에 관한 연구 (A Study on the Dynamic Behavior of a 2-step Variable Valve Switching System for Automotive Engines)

  • 김동일;김도중
    • 한국자동차공학회논문집
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    • 제22권6호
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    • pp.39-48
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    • 2014
  • Variable valve actuation system is one of the widely used techniques to improve the fuel efficiency and power of automotive engines. 2-step variable valve actuation systems are also paid attention for the application to direct acting type valve train systems. Besides its advantages in size, weight, relatively simple structure, ets, however, 2-step variable valve actuation system has inherent disadvantages in dynamic instability of switching system to alter discontinuous lift modes. In this study, both experimental and analytical studies are performed to understand the dynamic behavior of a switching mechanism of a 2-step variable valve actuation system, and present a design method to improve its dynamic instability.

일차 Dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The Design of Variable Structure Controller for the Systems Having the First Order Dynamic)

  • 박귀태;최종경;김동식
    • 대한전기학회논문지
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    • 제41권4호
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    • pp.392-399
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    • 1992
  • This paper will describe the application of variable structure control theory to the first order dynamic system and verify its robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC,DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which is regarded as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

일차 dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The design of variable structure controller for the systems having the first order dynamic)

  • 박귀태;최중경;강윤관
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.179-184
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    • 1991
  • This paper will describe the application for variable structure control theory to the first order dynamic system and verify it's robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC, DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which regards as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

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가변형 임계노즐 유동에 관한 실험/수치해석적 연구 (Experimental / Computational Study of a variable Critical Nozzle Flow)

  • 김재형;김희동;박경암
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.167-173
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    • 2003
  • For the measurement of mass flow rate at a wide range of operation conditions, it is required that the critical nozzle gas different diameters, since the mass flow rate through the critical nozzle depends on the nozzle supply conditions and the nozzle throat diameter. In the present study, both computational and experimental investigations are performed to explore the variable critical nozzle. Computational work using the 2-dimensional, axisymmetric, compressible Navier-Stokes equations are carried out to simulate the gas flow through variable critical nozzle. In experimnet, a cylinder with several different diameters is inserted into the critical nozzle to vary the nozzle throat diameter. Computational results are compared with the experimented ones. The computed results are in close agreement with experiment. It is found that the displacement and momentum thickness of variable critical nozzle are given as a function of Reynolds numbers. The discharge coefficient of the variable critical nozzle is predicted using an empirical equation.

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The Effects of Korean Wave and Heuristic on Shopping Behavioral Intention of Chinese Consumers

  • Kim, Soon-Hong;Yoo, Byong-Kook
    • 유통과학연구
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    • 제15권9호
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    • pp.53-62
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    • 2017
  • Purpose - This study aims to analyze the effects of preference for Korean Wave and heuristic on shopping satisfaction and switching barriers of Chinese people visiting Korea, and also their positive effects on consumers' behavioral intention with these variables as mediating variables by using the structural equation model. Research design, data, and Methodology - For this study, we collected 264 questionnaires of Chinese consumers' who have experienced tourism and shopping in Korea after excluding questionnaires that were not proper to be analyzed. The residence of Chinese visiter was Shandong Province, Beijing, Shanghai, Shenyang. The data of this study was analyzed using SPSS 23 statistics to verify the reliability and discriminant validity. Structural equation method was used to test the hypotheses in this study. Results - The effects of heuristic variable on shopping satisfaction and the switching barriers variable were statistically significant. The effects variables of Korean Wave effect variable were statistically significant only on the switching barriers variable. However, the Korean Wave effect variable did not have a statistically significant effect on the shopping satisfaction. Conclusions - The shopping satisfaction and Korean Wave effect variables had statistically significant effects on the behavioral intention variable. In the result of indirect analysis, only the heuristic effect had indirect effects on consumers' behavior intention.