• 제목/요약/키워드: Research dynamics

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Implementation and Test of the Automatic Flight Dynamics Operations for Geostationary Satellite Mission

  • Park, Sang-Wook;Lee, Young-Ran;Lee, Byoung-Sun;Hwang, Yoo-La;Galilea, Javier Santiago Noguero
    • Journal of Astronomy and Space Sciences
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    • 제26권4호
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    • pp.635-642
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    • 2009
  • This paper describes the Flight Dynamics Automation (FDA) system for COMS Flight Dynamics System (FDS) and its test result in terms of the performance of the automation jobs. FDA controls the flight dynamics functions such as orbit determination, orbit prediction, event prediction, and fuel accounting. The designed FDA is independent from the specific characteristics which are defined by spacecraft manufacturer or specific satellite missions. Therefore, FDA could easily links its autonomous job control functions to any satellite mission control system with some interface modification. By adding autonomous system along with flight dynamics system, it decreases the operator's tedious and repeated jobs but increase the usability and reliability of the system. Therefore, FDA is used to improve the completeness of whole mission control system's quality. The FDA is applied to the real flight dynamics system of a geostationary satellite, COMS and the experimental test is performed. The experimental result shows the stability and reliability of the mission control operations through the automatic job control.

회전 차축 및 유기압 현가장치를 장착한 대용량 세미 트레일러의 주행 동특성 해석 (Analysis for the Driving Dynamic Characteristics of Large Scale Semi-Trailer Equipped with Swivel Axle and Hydropneumatic Suspension Unit)

  • 하태완;박정수
    • 한국군사과학기술학회지
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    • 제25권2호
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    • pp.196-209
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    • 2022
  • Driving dynamic characteristics of semi-trailer loaded with precise equipments are very important to protect them from vibration, impact or other disturbances. In this paper, in order to identify the driving dynamic characteristics of the large scale semi-trailer equipped with swivel axle and hydropneumatic suspension unit, Dynamics Modeling & Simulation(M&S) were performed using general Dynamics Analysis Program(RecurDyn V9R2). The semi-trailer was modeled as two types - one is Multi Rigid Body Dynamics(MRBD) model, and the other Rigid-Flexible Body Dynamics(RFlex) one. The natural vibration mode and frequencies of semi-trailer body, acceleration of dummy-weight, pitch, roll and yaw of dummy-weight, swivel axle and hydropneumatic suspension cylinder support structure, and acting force of hydropneumatic suspensions etc. were obtained from the M&S. Additionally frequency analysis were performed using the data of behavior obtained from above M&S. Generally the quantitative results of RFlex are larger than them of MRBD in view of magnitude of the comparable parametric values.

등가답면구배를 목적함수로 하는 차륜답면형상 설계기법 (Design Method of Railway Wheel Profile with Objective Function of Eqivalent Conicity)

  • 허현무;유원희;박준혁;김민수
    • 한국정밀공학회지
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    • 제27권8호
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    • pp.13-19
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    • 2010
  • A design method of railway wheel profile with objective function of equivalent conicity considering wheel dimension constraint, two points contact problem between wheel and rail was proposed. New design method shows good results. New wheel profile generated from optimization process shows better dynamic performance compared with initial profile as the purpose of wheel profile design. And to verify the design method with testing the stability of new wheel profile, we conducted a critical speed test for new wheel profile using scale model applied scaling method of railway vehicle dynamics. The result of critical speed test show good agreement with that of numerical analysis. From the above results, it is seen that the design method with objective function of equivalent conicity is feasible and it could be applied to design new wheel profile efficiently.

시스템다이내믹스를 활용한 마음챙김과 치료관계 간의 동태적 분석 (Dynamic Analysis of Mindfulness and Therapeutic Relationship using System Dynamics)

  • 최연희
    • 한국시스템다이내믹스연구
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    • 제17권3호
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    • pp.121-143
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    • 2016
  • The purpose of this study to analyze the effect of Mindfulness on the Therapeutic Relationship using System Dynamics. The biggest factor in psychotherapy's treatment outcome is the Therapeutic Relationship including the quality of the therapist (empathy, therapeutic presence) and therapy alliance. Mindfulness practice can facilitate the therapeutic relationship. In order to analyze the therapeutic relationship, I measure FFMQ(Five Facet Mindfulness Questionnaire), Empathy, Therapeutic presence and Therapy alliance. Participants consist of 55 mental health professionals (doctor, psychologist, psychiatrist, counselor, social worker). The result of the study will be explained. First, with the causal loop diagram research, I analyze how mindfulness can influence the quality of therapist and therapy alliance. The result of literature research indicate that mindfulness increase therapist's empathy, congruence, therapeutic presence, flow, therapy alliance. And then mindfulness reinforces the ability of therapeutic relationship. Secondly, through the real data research and simulation analysis, mindfulness practicing period (year and hour a day) of therapist is studied. The result of the therapist experiencing mindfulness practice period is over 5 years and the daily hours of practice is 2 - 2.5 hours in order to enhance the therapeutic relationship. After reviewing the result of the research it is important to understand the practicing period and daily practice of mindfulness. With daily practice and time, the level of mindfulness will increase and influence positively the therapeutic relationship between therapist and client.

시스템다이내믹스를 활용한 인력 수급 계획 모형설계 (Demand Plan of Manpower Model Design Using System Dynamics)

  • 정재림;전소연;곽미애;연승준
    • 한국시스템다이내믹스연구
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    • 제8권1호
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    • pp.49-66
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    • 2007
  • Due to criminal aspects spreading nation wide, their intelligence level increasing and becoming digitalized, the citizens' interest in and desire for crime security have increased. Until now, the preceding researches have been focused on finding the specific variables that have direct effects on the demand for police manpower through regression analysis and attempted to predict number of needs. However, there have never been any researches producing the accurate number of demands for crimes and human resources needed for each work load. Therefore, this research have analyzed each police station functions by interviewing the persons in charge and selected the main duty for each functions. From this, by using the method of system dynamics, this research was able to predict the standard number of manpower needed for each police station functions. Also, by making a model for each 235 police stations, the best efficient employment plan for police stations and district agencies have been further discussed based on the computer simulation results.

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제약산업에서 FDA규제 영향에 관한 시스템 다이내믹스 모델링: FDA규제가 R&D비용에 미치는 영향을 중심으로 (System Dynamics Modeling for FDA Regulation Effect of Pharmaceutical Industry)

  • 고성필;최정환;남동욱;이정동
    • 한국시스템다이내믹스연구
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    • 제13권4호
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    • pp.57-80
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    • 2012
  • This research studies effect of FDA regulations in pharmaceutical industry on new drug development. System dynamics is implemented to demonstrate dynamic relationship between FDA regulations and R&D costs, firm's profits, sales. This research is focused on clinical trials of new medical entity process 50~60% portion of total development cost. Simulation results say that firm's profit is more sensitive to increasing the regulation than alleviating the regulation and effect of regulation policy make different result depending on the intensity of regulation and policy direction. Our simulation model provides the instrumental means for the policy makers and strategic decision in pharmaceutical industry.

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도시교통과 환경간의 동태적 관계와 정책실험논리 (feedback approach for the dynamic interactions between urban transportation and air pollution)

  • 최남희;김선경
    • 한국시스템다이내믹스연구
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    • 제2권2호
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    • pp.97-118
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    • 2001
  • To solve the policy problem between transportation and environment in trade-offs, above all, it is necessary to understand the complicated relationship between transportation and environment clearly before selecting policy alternatives. From this point of view, this study will propose the logic structure to examine the complex interaction of transportation and environment and investigate theoretically what kinds of impact would appear by the air related polices. In this research, we used ’system-dynamics’ which investigates the complexity through the flow of information and materials and the interaction of elements, which constitutes systems. System Dynamics is an approach that the variables to decide structural relationship in a system affect one another not in only-way but in inter-way and the power of influence changes time by time. This research is trying to examine the complex interaction of transportation and air pollution. For achieving this purpose, causal maps in System Dynamics approach were used. The main issues are as follows; first, to investigate the dynamic relationship between transportation and air pollution caused by exhaust emission gas. Second, to structuralize the logic of simulation to experiment the impacts of policies to relieve air pollution.

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Model Reference Adaptive Control Using Non-Euclidean Gradient Descent

  • Lee, Sang-Heon;Robert Mahony;Kim, Il-Soo
    • Transactions on Control, Automation and Systems Engineering
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    • 제4권4호
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    • pp.330-340
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    • 2002
  • In this Paper. a non-linear approach to a design of model reference adaptive control is presented. The approach is demonstrated by a case study of a simple single-pole and no zero, linear, discrete-time plant. The essence of the idea is to generate a full non-linear model of the plant dynamics and the parameter adaptation dynamics as a gradient descent algorithm with respect to a Riemannian metric. It is shown how a Riemannian metric can be chosen so that the modelled plant dynamics do in fact match the true plant dynamics. The performance of the proposed scheme is compared to a traditional model reference adaptive control scheme using the classical sensitivity derivatives (Euclidean gradients) for the descent algorithm.