• Title/Summary/Keyword: and system dynamics

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Incorporating Social & Economic Factors for the Pasture Project in Kum River (금강 참게목장화 사업의 사회-경제 통합모델링)

  • Jeon, Dae-Uk
    • Korean System Dynamics Review
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    • v.12 no.1
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    • pp.59-74
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    • 2011
  • This article deals with an economic evalutation of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs in a stream of it. An augmented model of social capital is based on the past ecological-economic system dynamics model and elaborated further with suggestions of social capital literature. During the modeling process a chain diagram of causal relations and its relevant mathematical equations are presented for simulating the project performance, and the simulation results are provided to contrast the dynamic behaviors of the former ecological-economic model with ones of the new model incorporating social capital. The results indicate that an increase in the economic benefit of the project could happen in case of considering the process of social capital accumulation around the case area, which can be regarded as a remarkable trial to approve the common confidence in the role of social capital to enhance an economic achievement.

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Development of Competitive Port Model Using the Hybrid Mechanism of System Dynamic Method and Hierarchical Fuzzy Process Method (SD법과 HFP법의 융합을 이용한 항만경쟁모델의 개발)

  • 여기태;이철영
    • Korean System Dynamics Review
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    • v.1 no.1
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    • pp.103-131
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    • 2000
  • If a system such as a port has a large boundary and complexity, and the system's substance is considered as a black box, forecast accuracy will be very low. Futhermore various components in a port exert significant influence on each other. To copy with these problem the form of structure models were introduced by using SD method. The Competitive Ports Model had several sub-systems consisting of each Unit Port models, and each Unit Port model was made by quantitative, qualitative factors and their feedback loops. The fact that all components of one port have influence on the components of the other ports should be taken into account to construct Competitive Port Models. However, with the current approach that is impossible, and in this paper therefore, models were simplified by HFP adapted to integrate level variables of unit port models. Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, a new algorithm called ESD(Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia.

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Application of System Dynamics Methodology for Comprehensive Analysis of the Water Business System (수도시스템 사업성과의 통합적 분석을 위한 시스템 다이나믹스 방법론 적용)

  • Lee, Sangeun;Park, Hyeyeon;Park, Heekyung
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.1
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    • pp.65-73
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    • 2007
  • To consider business-based requirements beyond the existing roles of water supply, water utilities need enough methodology to integrate lots of related issues and to introduce effective decision-makings. On these grounds, this study modeled and simulated water business system using system dynamics approach. It is expected that formalised model can describe the actual system structurally and statistically, help utilities to predict their business performance and make decisions to solve chronic issues. Moreover, the case study of Y city gave political measures objectively and practically.

Robust Adaptive Control for the System with Unmodelled Dynamics (비모형화 특성을 갖는 시스템의 견고성 적응제어)

  • 김성덕;양해원
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.9
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    • pp.670-677
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    • 1987
  • The robustness and stability properties for a model reference adaptive control system with plant uncertainty are considered in this paper, using input-output stability theory. An error model for a typical adaptive control structure is extended to unmodelled dynamics in the plant model and then, the strictly positive real condition for global stability is examined. In general, since this condition can be easily violated due to unmodelled dynamics, a modified compensator which can be guaranteed Hev e SPR is introduced in the plant model and the effectiveness for the given structure is also given.

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Dynamic Analysis of the Latch Needle of the Circular Knitting Machine (환편기 편직바늘의 동역학해석)

  • Jeong, K.Y.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.584-589
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    • 2001
  • The latch needle cam system of circular knitting machines is analysed using multibody dynamics. A formulation is made to obtain the vertical stiffness between the needle and the cam. By implementing this formulation into data of the multibody dynamics program, the motion and the force between the needle and the cam are obtained.

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Hydraulic System Modeling far Dynamic Track Tensioning System in Tracked Vehicles (궤도차량의 동적 궤도장력 조절시스템을 위한 유압시스템의 동적 모델링)

  • 허건수;임훈기;서문석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.04a
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    • pp.282-287
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    • 2003
  • DTTS(Dynamic Track Tensioning System) system requires robust control performance for the various maneuvering tasks. However, it is very difficult to tune the controller gains in experiments. In this paper, the hydraulic unit is modeled and constructed into the DTTS control module in Matlab/Simulink The control module is interfaced to the vehicle dynamics module so that the control performance of the DTTS system can be evaluated in simulations. The dynamics data and control input data are exchanged between two modules at each control time-step. The gains in the fuzzy-logic controller are varied and the control performance is evaluated in simulations. The proposed simulation tool can be very useful for the gain tuning of track tension controller in bucked vehicles

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A Study on Dynamic Models for Ports and Regional Economy (항만과 지역 경제간의 동태적 모델에 관한 연구)

  • 오세웅;여기태;이철영
    • Korean System Dynamics Review
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    • v.2 no.1
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    • pp.29-50
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    • 2001
  • A System such as a port and regional economy has a large boundary and complexity. So, not only the system's state is considered as a black box but system's forecast accuracy is very low. Futhermore various components in a port and regional economy influence significantly on each other. To copy with these problem the form of structure models were introduced by suing SD model. This study has the issue of simplifying the regional economic effects of the port as contributng to raising the regional income. The regional economic effects of port have various indirect ones except for this. So, SD(System Dynamics) was presented, and applied to simulate port and regional economy.

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Construction of New Administrative Capital and Urban Dynamics Analyses (신행정수도의 건설과 도시동태성 분석)

  • 이만형;최남희
    • Korean System Dynamics Review
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    • v.4 no.1
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    • pp.69-91
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    • 2003
  • Using qualitative methods hinged on urban dynamics models, the paper addresses major issues concerned with new administrative capital construction. It tries to summarize the existing debates on new administrative capital construction and reinterpret diverse interacting factors in terms of reinforcing or balancing feedback structure. The paper suggests that understanding up on the dynamic mechanism imbedded in circular causal loop diagrams is the key to set up appropriate proposals and action plans for the new administrative capital, as they would reveal complicated linkages between the Capital Region and the rest, in addition to the urban dynamic of new administrative capital. In the same context, the paper can confirm similar features reflected in the relocation of capital functions at Canberra, Australia and Berlin, Germany. It has paid special attention to the fact that both Australian and German governments altogether stress the positive feedback loops as they have overcome unprecedented political confrontation among rival cities: Basically, they have encouraged gives-and-takes among major stake-holders. These research findings indicate that the future of new administrative capital construction depends on consensus buildings that can accommodate socio-economic and territorial changes between pros and cons. Although further researches and validations are needed, the system approach presented in this paper could assist Korean decision-makers in developing robust and responsive policy initiatives under uncertainties.

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Application of the fault detection filter to detect the dynamic faults of a two-motor driven electric vehicle system (Detection Filter를 적용한 two-motor구동방식 전기자동차의 고장감지에 관한 연구)

  • 김병기;장태규;박정우
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.341-344
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    • 1997
  • This paper presents a dynamics failure detection algorithm developed for the two-motor-driven electric vehicle system. The algorithm is based on the application of the fault detection filter. The fault detection includes the identification of sudden pressure drops of the two rear tires in driving axis and dynamics faults of the two inverter-motor-paired actuators An E.V. dynamics simulator is developed, which includes the modeling of the E.V. dynamics as well as the driving dynamics. The simulator, which allows the generation of various fault situations, is utilized in the verification of the developed fault detection algorithm. The results of the simulations are also presented.

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DQ Synchronous Reference Frame Model of a Series-Parallel Tuned Inductive Power Transfer System (직렬-병렬 공진 무선전력전송 시스템의 동기 좌표계 모델)

  • Noh, Eun-Chong;Lee, Sang-Min;Lee, Seung-Hwan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.6
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    • pp.477-483
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    • 2020
  • This study proposes a DQ synchronous reference frame model of a series-parallel tuned inductive power transfer (SP-IPT) system. The wireless power transmission system experiences control difficulty because the transmitter-side controller cannot directly measure the receiver-side load voltages and currents. Therefore, a control-oriented circuit model that shows the dynamics of the IPT system is required to achieve a well-behaved controller. In this study, an equivalent circuit model of the SP-IPT system in a synchronously rotating reference frame is proposed using the single-phase DQ transformation technique. The proposed circuit model is helpful in modeling the dynamics of the voltages and currents of the transmitter- and receiver-side resonant tanks and loads. The proposed circuit model is evaluated using frequency- and time-domain simulation results.