• Proceedings of the Korean Association for Survey Research Conference
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• 2001.04a
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• pp.109.2-130
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• 2001

The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g., factor analysis), (2) to highlight the importance of the data analytic method considering group differences, and (3) to provide ways of incorporating group differences in data analysis. In study, 1, ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this, z-transform method and group analysis tool in covariance structure models were suggested. In study 2, the group differences effect was illustrated by using real data (IQ test data).

• Survey Research
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• v.2 no.2
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• pp.109-130
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• 2001

The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g.. factor analysis). (2) to highlight the importance of the data analytic method considering group differences. and (3) to provide ways of incorporating group differences in data analysis. In study 1. ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this. z-transform method and group analysis tool in covariance structure models were suggested. In study 2. the group differences effect was illustrated by using real data (IQ test data).

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.11-21
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• 2003

This paper deals with preliminary design results of autopilot for station keeping mode of airship. Linear equations of motion for the airship are derived. Basic architecture of the control laws for cruising and station keeping modes are proposed. Performance analysis results show that autopilot design for station keeping mode of airship is feasible.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.6
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• pp.1346-1360
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• 1989

본 연구에서는 기준 모델 적응제어 방식에서 직접 적응제어 방식을 사용하여 부하의 변동 및 외란이 발생할 경우에도 매니퓰레이터의 정확한 궤적의 추종 및 속도 의 실시간 제어가 가능한 적응제어시스템을 설계하고자 한다. 제2절에서는 로봇 매니퓰레이터의 기구학적 이론 및 동적 모델링에 대한 기본이론을 전개하고, 제3절 에서는 제어시스템의 설계를 위한 제어 알고리즘과 초안정(hyperstability)이론을 통한 안정성 해석을 다룬다. 그리고 제4절에서는 제안된 제어기의 성능 평가를 위해 6관절 로봇인 스탠포드 로봇 매니퓰레이터에 대한 시뮬레이션을 통한 결과를 토오크 계산법(computed torque method)에 의한 결과와 비교 검토함으로서 제안된 제어기의 성능을 예증한다.

• Journal of Korean Society of Rural Planning
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• v.11 no.2 s.27
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• pp.59-69
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• 2005

Because of increasing numbers of cars many highways are being constructed lively, and the noise of passing cars has influenced surrounding areas. In consideration of this, some alternatives and researches for soundproof facilities are proceeding, but aesthetic approach hasn't been considered. Therefore, this research is focused on soundproof effects for each types, effectual simulation methods, visual assessment and estimation between the landscape before simulation and the landscape after. Soundproof facilities are divided largely by the soundproof barrier, the soundproof mounding, the soundproof grove. The soundproof grove has three main function. First, leaves and branches absorbs sound vibrations. Second, leaves absorbs sound, and branches obstruct sounds. Third, by means of sounds of shaking leaves, forest can offset noises. This research was proceeded by means of classification of soundproof grove types and investigation of visual simulation methods. We made visual simulation for each types, and estimated the landscape for each types.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.40-48
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• 1987

In this paper strategic planning is applied for effective management to improve hospital income. Though community hospital has been set up for improving the health status of community, it must be trying to increase income for continuing with referral hospital in the community. The most useful tool of management to do this purpose is thought of strategic planning. Therefore this paper developed strategic planning a typical community hospital, which for it presenting the strategic planning process and developing the simulation model for evaluation of strategic alternatives. In the result it is represented that admission rate is the most sensitive to hospital operating income among the important variables in the model. And simulation by changing the parameter could estimate the yearly hospital income in the response of alternatives. This strategic planning simulation model has had constraints as number of date but also significance such as evaluating the alternatives by quantitative model and at first applying the hospital in our country.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.56-64
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• 1986

This paper describes a GPSS-based, multi-server queueing model that was developed to simulate the patient flow, and to analyze the effectiveness of the patient scheduling system under various conditions. Unpredictable and unacceptably long waits to receive the service at the outpatient department of a general hospital necessitated the study. Arrival and service time distribution needed for the simulation model were generated from actual arrival and service patterns observed during the peak hours. The simulation results show that a change in patient scheduling system (i.e. time interval between appointments, starting time. and the number of physicians) from a current system would significantly reduce the patient wait time. This study provides the hospital administrator with an analysis of patient scheduling system under several conditions, and will be used to plan future scheduling system and staffing. Studies such as this can demonstrate the value of simulation in providing information for use in future planning.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.341-343
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• 2012

This study introduces a method for computation of process and operation gap in the specific construction operation(i.e., RC frame construction applying a block-grouping scheme) using CYCLONE-based simulation modeling and analysis technique. Since uncertainty of construction environment exists, a thoughtful production planning is required to effectively deal with a risk resulting in schedule delay in advance. This study presents the concepts of a time delay occurred in a process level and operation level in a operation model, and a method of measuring gap-times in each level while the simulation progresses. It helps a site manager to decide how many segmentation in a construction block is suitable for eliminating unproductive time-delays under the constrained resources (e.g., laborer, equipment). A case study presents a network model representing a three segmented RC frame work, and result obtained from the simulation experiment.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.387-388
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• 2010

본 논문은 수십 MW용량의 풍력단지를 교류전력망에 연계하기 위한 다중펄스 컨버터와 PWM 컨버터로 구성된 Back-to-Back 컨버터를 제안하였다. 시뮬레이션 모델개발과 하드웨어 축소모형 실험을 통해 제안하는 Back-to-Back 컨버터의 시스템 구성 및 동작특성에 대해서 분석하고 3-레벨 24-펄스 컨버터를 영전압과 점호각을 제어할 경우와 점호각만을 제어할 경우 제어상의 장 단점과 제어성능을 비교분석하였다.

• Proceeding of EDISON Challenge
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• 2012.04a
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• pp.105-108
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• 2012

이차원 단면 Cylinder는 외부유동상태에서 후류에 Vortex를 생성한다. 또한 비정상 유동 상태에서는 후류에 카르만 Vortex열을 생성한다. 이런 이차원 Cylinder는 여러 분야에서 사용 된다. 이때 적절한 설계를 위해 수치적으로 유동을 해석할 필요가 있다. 이에 대한 수치적 해석 값을 얻기 위해 Edison CFD를 이용하여 여러 2차원 형상 Cylinder의 Reynolds number에 따른 Vortex shedding을 해석했다. Edison CFD를 통한 시뮬레이션 결과 값에 대한 검증을 얻기 위해 원형, 사각형의 Vortex shedding과 유동을 타 논문과 비교 검증했다. 형상마다 같은 조건의 Reynolds number라도 후류와 유동 등의 형상이 차이를 보인다. 상황마다 적절한 모형의 Cylinder를 Edison CFD를 통해 예측 할 수 있다.