• 제목/요약/키워드: Research variable

검색결과 6,598건 처리시간 0.042초

누설전류 예측을 위한 동적 시뮬레이션에 관한 연구 (A study on dynamic simulation for estimation of leakage current)

  • 정호성;한문섭;박영;정상기;권삼영;이재봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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    • pp.250-252
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    • 2008
  • DC traction system generates leakage current because running rails are used in return circuit. And it is very important to estimate the leakage current to the train operation situation. Therefore this paper presents dynamic simulation technique that is very similar to the real operation situation using TPS and PSCAD/EMTDC. For this we model DC traction system included in DC substation, variable feeding circuit model and variable train model. And we extract train location and power using TPS program and use these data for dynamic simulation. Finally we can estimate leakage current to the various operation condition using dynamic simulation.

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가변탭 변압기를 사용한 급전용량 증가 검토 (Examination of Increasing Power Delivery Capacity with variable Tab Autotransformer)

  • 이장무;한문섭;이한민;김주락;김길동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1163_1164
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    • 2009
  • AC AT feeding method consists return circuits of electric train inserting in parallel between trolly line and feeding line and connecting neutral line to rail and FPW. Due to increasing train number, electric load at feeding system are increasing and collecting voltage of train are going down. To increase electric load and collecting voltage between trolly line and rail, the usefulness of new autotransformer are considered which variation of short impedance and change of line voltage is simulated with modified winding ratio of autotransformer from 1:1 to variable tab.

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한국 경영정보학 연구 경향 분석 : 1974-1993 (An Analysis of the MIS Research in Korea : 1974-1993)

  • 백상용;박경수
    • Asia pacific journal of information systems
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    • 제5권2호
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    • pp.37-50
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    • 1995
  • This study analyzed 89 MIS published in Korea since 1974. The keyword classification scheme proposed by Barki et al. [1993] was employed to classify researched themes of the papers. Research methods and research variables were also examined. The results showed that (1) the Korean MIS research focused on DSS/ES, IS evaluation, IS development and operations, (2) nonempirical studies took 46% of the 89 papers while survey method was frequently used in empirical studies, (3) in empical studies, user-related variables were most frequently included as dependent variable while organization-related variables were most frequently selected as independent variable. Some recommendations for the future MIS research in Korea were suggested.

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Axial Shape Index Calculation for the 3-Level Excore Detector

  • Kim, Han-Gon;Kim, Yong-Hee;Kim, Byung-Sop;Lee, Sang-Hee;Cho, Sung-Jae
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 추계학술발표회논문집(1)
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    • pp.97-102
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    • 1997
  • A new method based on the alternating conditional expectation (ACE) algorithm is developed to calculate axial shape index (ASI) for the 3-level excore detector. The ACE algorithm, a type of non-parametric regression algorithms, yields an optimal relationship between a dependent variable and multiple independent variables. In this study, the simple correlation between ASI and excore detector signals is developed using the Younggwang nuclear power plant unit 3 (YGN-3) data without any preprocessing on the relationships between independent variables and dependent variable. The numerical results show that simple correlations exist between the three excore signals and ASI of the core. The accuracy of the new method is much better than those of the current CPC and COLSS algorithms.

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임파워먼트(Empowerment)가 호텔주방조직 구성원의 직무만족과 몰입에 미치는 영향에 관한 연구 (The Effects of Empowerment on Job Satisfaction, Commitment, Culinary Staff in the Hotel)

  • 김기영;염진철
    • 한국조리학회지
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    • 제9권4호
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    • pp.136-151
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    • 2003
  • The summarized analysis result of this research is as follows. First, regarding the difference of preceding variable and dependent variable, statistically considerable difference did not appear between self determination and personal relations in educational background and between groups of self determination in hotel type, and statistically considerable difference appeared among other groups. Second, regression analysis result between empowerment and job satisfaction turned out that statistically considerable influence is exerted in the order of personal relations ability, influence power, role performance ability and self-decision nature. Third, regression analysis result between empowerment and job devotion turned out that statistically considerable influence is exerted in the order of personal relations ability, role performance ability and influence power. Fourth, regression analysis result between empowerment and organization devotion turned out that statistically considerable result is exerted in the order of influence power and personal relations ability. Fifth, it turned out that statistically relative high correlation existed among correlation of empowerment and result variable such as job satisfaction, job devotion and organization devotion. The above-mentioned matters considered, this research proposes following points. This research examines the effect of empowerment on job satisfaction and organizational commitment of culinary staff in the hotel. the effect of the variable of empowerment on result variable shows that role performance ability, influence power and personal relations ability are important variables. Therefore, to improve the role performance ability of members of kitchen, it is essential for each individual to improve their ability and to have confidence at the time of business performance. So, this research implies that consistent and systematic training is necessary for increasing the ability and confidence. In order to improve influence power, it is necessary for members of an organization to have strong faith that their jobs determine the success of the company, and to increase the sense of self-control by letting them have the right of self determination, so that all members may have strong desire to transact business. This research implies that in order to improve personal relations ability, it is necessary for members of an organization to discover the best method of decision-making and solve problems through members' developing mutual action, and for managers to take personal characteristics into account so that members may have belief and confidence in their job and realize the value of their job. In conclusion, the person in charge of personnel affairs and the manager in charge of kitchen need to realize the importance of empowerment and especially have an much interest in all parts including self determination, influence power and role performance ability and personal relations ability etc.

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탄성콘크리트 댐의 모양최적설계 (Shape Optimal Design of Elastic Concrete Dam)

  • 유영면
    • 대한토목학회논문집
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    • 제5권4호
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    • pp.9-14
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    • 1985
  • 본 연구에서는 평면 변형도상태 하에서 정수압을 받는 2차원 탄성 콘크리트 댐의 단면 모양을 최적화함으로써 댐의 질량을 최소화하였다. 최적화 문제의 목적함수로는 댐의 단면적이, 제약조건으로는 주응력 제약조건과 두께 제약조건들이, 설계변수로는 모델 경계의 모양이 채택되었다. 모델 영역의 변화에 따른 설계감도해석을 위해 최적화 문제를 범함수 형태로 변환한 후 연속체 역학의 물질미분 개념과 Adjoint Variable Technique 을 활용하였고, 최적화를 위해서는 Gradient Projection Method 를 사용하였다. 연구 결과 본 연구에 적용된 이론이 효율적이고 실제 탄성구조물 설계에 광범위하게 응용될 수 있음이 밝혀졌다.

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Higher order flutter analysis of doubly curved sandwich panels with variable thickness under aerothermoelastic loading

  • livani, Mostafa;MalekzadehFard, Keramat;Shokrollahi, Saeed
    • Structural Engineering and Mechanics
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    • 제60권1호
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    • pp.1-19
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    • 2016
  • In this study, the supersonic panel flutter of doubly curved composite sandwich panels with variable thickness is considered under aerothermoelastic loading. Considering different radii of curvatures of the face sheets in this paper, the thickness of the core is a function of plane coordinates (x,y), which is unique. For the first time in the current model, the continuity conditions of the transverse shear stress, transverse normal stress and transverse normal stress gradient at the layer interfaces, as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of the sandwich panel are satisfied. The formulation is based on an enhanced higher order sandwich panel theory and the vertical displacement component of the face sheets is assumed as a quadratic one, while a cubic pattern is used for the in-plane displacement components of the face sheets and the all displacement components of the core. The formulation is based on the von $K{\acute{a}}rm{\acute{a}}n$ nonlinear approximation, the one-dimensional Fourier equation of the heat conduction along the thickness direction, and the first-order piston theory. The equations of motion and boundary conditions are derived using the Hamilton principle and the results are validated by the latest results published in the literature.

학습자 개인특성이 6시그마 활용에 미치는 영향과 조직의 학습문화 및 조직지원의 구조적 역할 (The Influence of Learner's Individual Characteristics on Using Six Sigma and the Structural Role of an Organization's Learning Culture and its Support)

  • 최승은;김민선;강소라
    • Journal of Information Technology Applications and Management
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    • 제17권2호
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    • pp.19-45
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    • 2010
  • This research has analyzed the differentiated influence of organizational variables(an organization's learning culture and organizational support networks) and personal variables(the individual's motivation to learn and self-efficacy) on the process of gaining and using of knowledge. These two variables have been regarded as the major variables for the successful learning of 6Sigma, according to Social Cognitive Theory. In addition, this research has proven the role structure of the abovementioned two variables through a suitable methodology(Hierarchical Linear Model). In regard to this methodology, the different hierarchical level of the personal variable and organizational variable was especially focused on, and the effect of interaction between the high level and the low level was considered in detail. Considering the current situation, in that the importance of organizational factor and personal factor has been emphasized but the accurate role of each variable has not been verified, the research model is thought to help to establish an effective strategy to implement 6 Sigma.

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