• Title/Summary/Keyword: dynamics

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A Review of Solid Waste Management using System Dynamics Modeling

  • Popli, Kanchan;Sudibya, Gamal Luckman;Kim, Seungdo
    • Journal of Environmental Science International
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    • v.26 no.10
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    • pp.1185-1200
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    • 2017
  • Solid waste management is currently a topic of concern, particularly in the protection of humans and the environment from toxic pollutants and hazardous materials. The importance of solid waste management is recognized at international, national, and community levels. Different agendas have been prioritized and assigned to improve quality of life, productivity, and health, and reduce the burden of pollution. Suitable management of solid waste requires appropriate technology that is affordable, socially accepted, and environmentally friendly. The use of a smart management system involving system dynamics can save energy, money, and labor. System dynamics is a computer-based approach that aids in predicting the behavioral patterns of variables, and correlating dependent and independent variables. The inclusion of system dynamics-based models in solid waste management has recently become more common. In this review, we used system dynamics to determine methods to disentangle solid waste management systems and analyzed different studies on solid waste management using system dynamics in different countries in detail. We also discussed the various software packages that are available for system dynamics and their usefulness for waste management. This review may help in understanding current solid waste management practices using system dynamics.

Research Progress of the Structure Vibration-Attitude Coordinated Control of Spacecraft

  • Yang, Jingyu;Qu, Shiying;Lin, Jiahui;Liu, Zhiqi;Cui, Xuanming;Wang, Chu;Zhang, Dujiang;gu, Mingcheng;Sun, Zhongrui;Yang, Kang;Zhou, Lanwei;Chen, Guoping
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.4
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    • pp.590-601
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    • 2015
  • This paper gives an overview of research on the field of structure vibration-attitude coordinated control of spacecraft. First of all, the importance of the technology has been given an introduction, and then later the research progress of space structure dynamics modeling, research progress of structure vibration-attitude coordinated control of flexible spacecraft have been discussed respectively. Finally, future research on application of structure vibration-attitude coordinated control of spacecraft has been recommended.

System Dynamics Approach for the Forecasting KOSPI (시스템다이내믹스를 활용한 종합 주가지수 예측 모델 연구)

  • Cho, Kang-Rae;Jeong, Kwan-Yong
    • Korean System Dynamics Review
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    • v.8 no.2
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    • pp.175-190
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    • 2007
  • Stock market volatility largely depends on firms' value and growth opportunities. However, with the globalization of world economy, the effect of the synchronization in major countries is gaining its importance. Also, domestically, the business cycle and cash market of the country are additional factors needed to be considered. The main purpose of this research is to attest the application and usefulness of System Dynamics as a general stock market forecasting tool. Throughout this research, System Dynamics suggests a conceptual model for forecasting a KOSPI(Korea Composite Stock Price Index), taking the factors of the composite stock price indexes in traditional researches. In conclusion of this research, System Dynamics was proved to bean appropriate model for forecasting the volatility and direction of a stock market as a whole. With its timely adaptability, System Dynamic overcomes the limit of traditional statistic models.

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Population Ageing Crisis and Causal loop Analysis on the It's Dynamics in Rural County Regions (우리나라 군지역의 고령화 위기와 동태성의 인과순환적 구조분석)

  • Choi, Nam Hee;Lee, Jong Kun;Kim, Keun Sei;Lee, Myung Suk
    • Korean System Dynamics Review
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    • v.15 no.1
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    • pp.75-96
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    • 2014
  • This research primarily aims at analyzing major crises originating from marginalizing population, especially in counties. In addition, based on the system dynamics approaches, it pays attention to divulging causal loop structure which has been rather strengthened by diverse interactions among key variables. Judging from simulation works, even though Korea is exposed to unprecedented aging trends over decades, its counter response seems inadequate and insufficient, mostly dismissing a series of impact embedded in the aging dynamics. This research statistically confirms that demographic marginalization trends have already begun in the villages within Eup and Myon counties. Furthermore, this research pinpoints out the fact that it would be almost impossible for majority of villages within Eup and Myon counties to escape from going out of existence in the course of time, as they tend to be entrapped vicious cycle of marginalization or extinction.

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Wind Turbine Simulation Program Development using an Aerodynamics Code and a Multi-Body Dynamics Code (풍력발전시스템의 유연체 다물체 동역학 시뮬레이션 프로그램 개발)

  • Song, Jin-Seop;Rim, Chae-Whan;Nam, Yong-Yun;Bae, Dae-Sung
    • New & Renewable Energy
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    • v.7 no.4
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    • pp.50-57
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    • 2011
  • A wind turbine simulation program for the coupled dynamics of aerodynamics, elasticity, multi-body dynamics and controls of turbine is newly developed by combining an aero-elastic code and a multi-body dynamics code. The aero-elastic code, based on the blade momentum theory and generalized dynamic wake theory, is developed by NREL(National Renewable Energy Laboratory, USA). The multi-body dynamics code is commercial one which is capable of accounting for geometric nonlinearity and twist deflection. A turbulent wind load case is simulated for the NREL 5-MW baseline wind turbine model by the developed program and FAST. As a result, the two results agree well enough to verify the reliability of the developed program.

Institutional political dynamics: political cycles between the liberal and the conservative

  • Kim, Dong-Hwan;Saeed, Khalid
    • Korean System Dynamics Review
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    • v.13 no.3
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    • pp.5-22
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    • 2012
  • Although many system dynamists point out the close relationship between institutional economics and system dynamics, the relationship between institutional political theory and system dynamics approach is not explicitly appreciated yet. We developed a system dynamics model to investigate theoretical propositions of institutional politics. Our system dynamics model showed how the endogenous mechanism can explain the political changes as well as orders. Although simple in the causal structure, our model could show a complex behavior of political competition. Several simulation results imply that some unexpected changes in election and power competition may come from the endogenous system rather than from exogenous factors such as economic and environmental shocks.

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Recent Trends in Multibody Dynamics Researches reviewed from the papers presented in the Multibody2003 and in the 2003 ASME DETC (Multibody2003와 2003 ASME DETC의 논문들을 통해본 다물체동역학 연구의 세계적 연구추세)

  • Yoo, Wan-Suk
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1714-1717
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    • 2003
  • ECCOMAS Thematic Conference Multibody 2003 was held at IST (Instituto Superior Technico), Lisbon, Portugal from July 1 to July 4. 2003. And MBDV(Multibody Dynamics and Vibration) in the 2003 ASME DETC was held at Chicago, U.S.A. from September 2 to September 6. In this paper, the presented papers in these conferences were reviewed and the trends in the multibody dynamics are summarized. The session titles in these conferences include Flexible Multibody Dynamics, Vehicle Dynamics, Contact, Biomechanics, Real-time Challenges, Spatial manipulator and Control, Multidisciplinary Applications, and Advanced Education. The poster session was also organized for more discussions in the Multibody2003 conference.

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A System Dynamics Model for Basic Material Price and Fare Analysis and Forecasting (시스템 시뮬레이션을 통한 원자재 가격 및 운송 운임 모델)

  • Jung, Jae-Heon
    • Korean System Dynamics Review
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    • v.10 no.1
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    • pp.61-76
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    • 2009
  • We try to use system dynamics to forecast the demand/supply and price, also transportation fare for iron ore. Iron ore is very important mineral resource for industrial production. The structure for this system dynamics shows non-linear pattern and we anticipated the system dynamic method will catch this non-linear reality better than the regression analysis. Our model is calibrated and tested for the past 6 year monthly data (2003-2008) and used for next 6 year monthly data(2008-2013) forecasting. The test results show that our system dynamics approach fits the real data with higher accuracy than the regression one. And we have run the simulations for scenarios made by possible future changes in demand or supply and fare related variables. This simulations imply some meaningful price and fare change patterns.

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Design of new sliding mode control system using discrete-time switching dynamics and its stability analysis (이산 시간 스위칭 다이나믹을 이용한 새로운 슬라이딩 모드 제어 시스템의 설계 및 안정도 해석)

  • 김동식;서호준;서삼준;박귀태
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.407-414
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    • 1996
  • In this paper we consider the variable structure control for a class of discrete-time uncertain multivariable systems where the nominal system is linear. Discrete-time switching dynamics are introduced so that a new type of state trajectories called sliding mode may exist on the sliding surface by state feedback. The quantitative analysis for the matched uncertainties will show that every response of the system with the proposed switching dynamics is bounded within small neighborhoods of the state-space origin. Also, by the similarity transformation it will be shown that the eigenvalues of the closed-loop systems are composed of those of the subsystems which govern the range-space dynamics and null-space dynamics. It will be also shown that ideal sliding mode can be obtained in the absence of uncertainties due to one-step attraction to the sliding surface regardless of initial position of states. (author). 12 refs., 2 figs.

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Study on the Role of Hospital Coordinators with System Dynamics Approach (병원 코디네이터도입이 병원경영성과에 미치는 영향분석)

  • Chung, Hee-Tae
    • Korean System Dynamics Review
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    • v.11 no.4
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    • pp.5-23
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    • 2010
  • The competition between hospitals has become an issue for many hospitals because of the sudden increased number of health providers. As the marketing or customer management have become important factors as means of competition, a number of hospital have been considered or already adopted the coordination system. A system dynamics model is developed to see the effect of the hospital coordination system. This paper after briefly explaining the structure of the system dynamics model, discusses the roles of the hospital coordination system with examples. The system dynamics model quantifies through simulations the process of effects of coordination system on the number of customers, productivities of employees (nurses and doctors), and finally the financial status. As a conclusions of the simulations and their analysis, it is concluded that coordination system could be more effective than the investment to the facilities. Since the study is based on only one hospital case, it is limited. However, it explains the mechanism of the coordination system quantitatively as well as qualitatively.

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