• 제목/요약/키워드: Variable Step

검색결과 806건 처리시간 0.027초

가정폭력 노출 경험이 남녀 대학생의 정신건강에 미치는 영향 - 사회적 지지 자원의 조절효과를 중심으로 - (The Impact of Domestic-Violence Exposure Experience on Mental Health among Male and Female College Students: - Focused on the Moderating Effects of Social Support Resources -)

  • 박주희
    • 가족자원경영과 정책
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    • 제20권3호
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    • pp.131-149
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    • 2016
  • The aims of this study are to investigate the impact of the experience of exposure to domestic violence(witnessed interparental conjugal violence and child abuse) on mental health among college students, and to explore whether social support acts as a moderator between domestic violence and mental health. Through this process, I intended to provide a reference base to suggest substantial interventions for family welfare by helping students to overcome negative domestic violence exposure experiences and adapt as healthy members of society. To achieve this goal, the study established a conceptual framework by considering the mental health of adolescents with domestic-violence exposure experience as a dependent variable, domestic violence exposure experience (witnessed interparental conjugal violence and child abuse) as an independent variable, and social support as a moderator of the relationship between these two variables. The subjects composed 747 college students in 8 colleges in Seoul. The main summary of this study is as follows: First, according to the analysis of domestic-violence exposure experience, all the subjects of this study had substantial experience of violence at home and witnessed interparental conjugal violence. These students scored 3.83 points in social support, higher than the median of 3, implying that these students had a higher awareness of social support. Moreover, their mental health score was 3.50 points, which is higher than the median of 3, indicating a somewhat positive tendency toward mental health. Second, to explore the moderating effects of social support between child violence experience and mental health, gender, age, financial status, academic-performance, child abuse and social support were input in the first step, and then buffering effects were examined by entering an interaction term to the first step in the second step. There was a significant interaction between social support and mental health. Therefore, social support was identified as having moderating effects on the relationship between child violence and mental health. Third, the analysis of moderating effects of social support between witnessed interparental conjugal violence and mental health revealed that social support had a positive influence on mental health in the first step. By contrast, the interaction term of witnessed interparental conjugal violence and social support showed no significance, indicating no moderating effect of social support in the second step. To sum up, social support served as a moderator for mental health among college students with child abuse experience, but had no moderating effect on witnessed interparental conjugal violence experience.

부식을 고려한 판형교의 LCC 분석 데이터구조 설계 (Data Structure Modeling for the LCC Analysis of the Plate Girder Bridge Considering Corrosion)

  • 김동현;김봉근;이상호
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.497-500
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    • 2007
  • Data structure was designed not only to estimate LCC but also to analyze time-variant reliability index of plate girder bridges. Information model for data structure was categorized into cost information, cost variable information, user cost information, and reliability analysis information according to the characteristic of data. EXPRESS language of STEP was adopted to describe the data structure for the electronic representation of LCC information. The suitability of the developed data structure was verified by estimating LCC and analyzing time-variant reliability index of a plate girder bridge considering corrosion on the basis of the constructed test database.

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Brushless DC Motor의 제어 파라미터 추정과 안정도향상 (The Parameter Estimation and Stability Improvement of the Brushless DC Motor)

  • 김철진;임태빈
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제48권3호
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    • pp.131-138
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    • 1999
  • Generally, the digital controller has many advantages such as high precision, robustness to electrical noise, capability of flexible programming and fast response to the load variation. In this study, we have established proper mathematical equivalent model of Brushless DC (BLDC) motor and estimated the motor parameter by means of the back-emf measurement as being the step input to the controlled target BLDC motor. And the validity of proposed estimation method is confirmed by the test result of step response. As well, we have designed the reasonable digital controller as a consequence of the root locus method which is obtained from the open-loop transfer function of BLDC motor with hall sensor, and the determination of control gain for variable speed control. Here, revised Ziegler-Nichols tuning method is applied for the proper digital gain establishment, and the system stability is verified by the frequency domain analysis with Bode-plot and experimentation.

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FEM을 이용한 외부고정구 영향에 의한 골-재형성에 대한 해석 (Analysis of bone-remodeling by the influence of external fixator with FEM)

  • 김영은;이원식
    • 대한기계학회논문집
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    • 제15권2호
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    • pp.436-444
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    • 1991
  • A computational method has been developed to analyze the bone-remodeling induced by external fixator. The method was based on the Finite Element Method (FEM) in combination with numerical formulation of adaptive bone-remodeling theories. As a feed-back control variable, compressive strain and effective stress were used to determine the surface remodeling and internal (density) remodeling respectively. Surface remodeling and internal remodeling were combined at each time step to predict the rel situation. A noticeable shape and density change were detected at the region between two pins and density change was decreased with time increment. At final time step, the shape and density distribution were converged closely to its original intact bone model. Similar change was detected in stress distribution. The altered stress distribution due to the pin and external fixator converged to the intact stress distribution with time.

Step 가변형 MPPT 제어기법과 DVR을 적용한 계통연계형 태양광 발전 시스템 (Grid-Connected Photovoltaic System Applying the Step Variable MPPT Control and DVR)

  • 이용식;정성원;김재현
    • 조명전기설비학회논문지
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    • 제26권8호
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    • pp.42-49
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    • 2012
  • Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

모형시험을 통한 Smart 양방향말뚝 재하시험에 관한 연구 (Study of Smart Bi-directional Pile Load Test by Model Test)

  • 김낙경;김웅진;주용선;김성규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.1088-1093
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    • 2010
  • The Smart bi-directional pile load test with variable end plate overcomes the shortcoming of the Osterberg cell test. It is possible that the ultimate bearing capacity of piles can be known by using two different end plates. The first step is to measure end bearing capacity with smaller end plate and the second step is similar to the conventional O-cell test. In this study, model test was performed to evaluate the smart bi-directional pile load test in sand. Vertical displacement of the model pile were messured at the axial loading condition.

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단단 축류압축기 유동해석에 대한 k-w 난류모델의 응용 (Application of k-w turbulence model to the analysis of the flow through a single stage axial-flow compressor)

  • 이준석;김광용
    • 한국유체기계학회 논문집
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    • 제3권3호
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    • pp.7-11
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    • 2000
  • A numerical study based on the three-dimensional thin-layer Navier-Stokes solver is carried out to analyze the flowfield through a single stage transonic compressor. Explicit fout-step Runge-Kutta scheme with spatially variable time step and implicit residual smoothing is used. The governing equations we discretized with explcit finite difference method. Mired-out average method is used at the interface between rotor and stator. And, an artificial dissipation model is used to assure the stability of solution. The results with k-w turbulence model were compared to the results with Baldwin-Lomax model, and physical phenomena of transonic compressor are presented. The two turbulence models give the results that show reasonably good agreements with experimental data.

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Soldering 방식에 따른 결정질 셀의 물리적 특성변화 (The Physical characteristic of Crystalline Solar Cell by Soldering Type)

  • 신준오;정태희;김태범;강기환;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.72-72
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    • 2010
  • The PV module company use variable process step and type. Especially soldering process is important, because crystalline cell can be bow by beating temperature. Most PV module company use hot air soldering type in the tabbing & string process. Although hot air type is used widely but this type is bound to influence on cell damage. So recently new way is introducing like a high current way. In this paper, we compare with characteristics of each soldering type and then conform a method to minimize solar cell deformation. Actually solar cell deformation show many difference by fix position and cooling time after soldering step.

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크리프 회복식을 이용한 철근콘크리트 및 프리스트레이트 콘크리트 부재의 크리프 해석에 고나한연구 (A Study on the Creep Analysis of Reinforced and Prestressed Concrete Structures Using Creep Recovery Function)

  • 오병환;김세훈;양인환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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    • pp.339-345
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    • 1998
  • The creep of concrete structures caused by variable stresses is mostly calculated by step-by-step method based on the superposition of creep function. Although most practical application is carried out by this linear assumption, significant deviations between predictions and experiments have been observed when unloading takes place, that is, stress is reduced. The recovery is overestimated. The main purpose of this study is to present the application method of the creep analysis model which is expressed with both creep function and creep recovery function to concrete structures where is expressed with both creep function and creep recovery function to concrete structures where increase or decrease of stress is repeated . To apply two function method to time analysis of concrete structures, this study presents the calculation method of creep strain increment for stress variation. Then, this paper executes the time analysis for an example using suggested method, and compares theses results with the previous analysis values and experimental results.

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비장착 엔진/나셀 형상에 대한 3차원 Euler 유동 해석 (Calculations of 3D Euler Flows around an Isolated Engine/Nacelle)

  • 김수미;양수석;이대성
    • 한국전산유체공학회지
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    • 제2권2호
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    • pp.51-58
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    • 1997
  • A reliable computational solver has been developed for the analysis of three-dimensional inviscid compressible flows around a nacelle of a high bypass ratio turbofan engine, The numerical algorithm is based on the modified Godunov scheme to allow the second order accuracy for space variables, while keeping the monotone features. Two step time integration is used not only to remove time step limitation but also to provide the second order accuracy in a time variable. The multi-block approach is employed to calculate the complex flow field, using an algebraic, conformal, and elliptic method. The exact solution of Riemann problem is used to define boundary conditions. The accuracy of the developed solver is validated by comparing its results around the isolated nacelle in the cruise flight regime with the solution obtained using a commercial code "RAMPANT. "

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