• 한국농공학회논문집
• /
• 제56권6호
• /
• pp.45-53
• /
• 2014

This study presents a system dynamics modeling approach to simulate daily streamflow in a watershed including wastewater treatment plant which contributes to irrigation water supply. The conceptual system dynamics model considering the complex and dynamic hydrological processes in the watershed was developed. The model was calibrated and validated each for two years based on observed flow data. Model performances in terms of $E_{NS}$, RSR, PBIAS, and $R^2$ were 0.64, 0.60, -3.6 %, and 0.64 for calibration period, and 0.66, 0.58, -2.6 %, and 0.66 for validation period, respectively, showing an applicability on generating the daily streamflow. System dynamics modeling approach could help better understand the hydrological behavior of the watershed being reused wastewater for agriculture, by providing graphical dynamics of the hydrological processes as well as conventional rainfall-runoff model results.

• 대한조선학회논문집
• /
• 제61권4호
• /
• pp.247-257
• /
• 2024

The present study suggests a data-driven multivariate identification method based on principal component analysis and shows an application to ship dynamics modeling in maneuver. A reduced order model of ship dynamics is built by linear combination of three principal components acquired from large angle zigzag maneuver test. For a given kinematic state with three variables, a proper span is found by least square method, therefore accompanying hydrodynamic force and moment is determined. Suggested dynamics model correctly estimates hydrodynamic force and moment, thus it showed good agreement in maneuver simulation with that of conventional ship dynamics model obtained by system identification of captive model tests.

• 한국자동차공학회논문집
• /
• 제7권9호
• /
• pp.212-219
• /
• 1999

This paper describes the NANDO VDC (Vehicle Dynamics Control) system for the vehicle stability enhancement and consists of the control strategies , computer simulation and tests on the various road surface. This VDC system controls the dynamic vehicle motion in the emergency situation such as the final oversteer/understeer andallows the vehicle to follow the course as desired by the driver. The system is based on an active yaw control and its performance verified by the test is shown. Also the comparison between the MANDO VDC System and a competitor is carried out.

• 소음진동
• /
• 제10권1호
• /
• pp.117-122
• /
• 2000

The dynamics of train has recently been analysed in many cases and very complex nonlinear creep theories have been developed by many engineers. But much calculation time is spent and latest complex creep theories cannot be adapted in train analysis. In this study efficient and fast train analysis method was suggested. Many of degree of freedom were reduced in multi-vehicle system using equivalent system and fast calculation time was achieved. And the accuracy of equivalent system method was proved by linear and nonlinear dynamic analysis.

• Smart Structures and Systems
• /
• 제8권2호
• /
• pp.205-217
• /
• 2011

This article describes the research work involving the implementation of an Active Bracing System aimed at the modification of the initial dynamics of a laboratorial building structure to a new desired dynamics. By means of an adequate control force it is possible to assign an entirely new dynamics to a system by moving its natural frequencies and damping ratios to different values with the purpose of achieving a better overall structural response to external loads. In Civil Engineering applications, the most common procedures for controlling vibrations in structures include changing natural frequencies in order to avoid resonance phenomena and increasing the damping ratios of the critical vibration modes. In this study, the actual implementation of an active system is demonstrated, which is able to perform such modifications in a wide frequency range; to this end, a plane frame physical model with 4 degrees-of-freedom is used. The Active Bracing System developed is actuated by a linear motor controlled by an algorithm based on pole assignment strategy. The efficiency of this control system is verified experimentally by analyzing the control effect obtained with the modification of the initial dynamic parameters of the plane frame and observing the subsequent structural response.

• 한국시스템다이내믹스연구
• /
• 제5권2호
• /
• pp.89-123
• /
• 2004

Using materials recovered from the waste stream instead of virgin resources as a raw material in manufacturing has great environmental and economic benefits. However, there is lack of public interest in needs for integrated waste management and its relevant facilities, because of NIMBY syndrome, This article has proposed a system dynamics model for the study of the potential and systemic consequences of resource circulation management system(RCMS) policy for a Sudokwon landfill site in Korea. The results of the study indicate that the effects of RCMS are seen continuously to increase in term with both the community welfare level and the resource and energy level. Moreover the effects of RCMS appear sharply in the first half of the simulation period.

• 한국시스템다이내믹스연구
• /
• 제14권1호
• /
• pp.55-68
• /
• 2013

It is necessary to evaluate the greenhouse gases (GHGs) reduction policy by central and regional governments to set up the suitable GHG emissions measures. Quantitative, qualitative and synthetic methods have been adopted by previous researches to estimate GHG reduction policy. However, these methods mostly focused on the results of the reduction policy, rather than understanding and fixing the integrated structures of GHG emissions. In this research, System Dynamics(SD) was applied to 1 million green homes program, self-carfree-day system and carbon point program. The results showed that SD analyses could be appliable for the estimation of GHG reduction policy by developing the feedback loops and dynamic simulation model. SD can be consider as a supplementary tool to estimate the GHG reduction policies through the recognition of the structure in complex real system.

• 한국시스템다이내믹스학회:학술대회논문집
• /
• 한국시스템다이내믹스학회 2000년도 학술대회발표논문집
• /
• pp.29-37
• /
• 2000

In this paper an attempt is made to understand contribution factors in the field of electronic commerce(EC). To do that, we adopt and modify an existing commerce model. The following two major conclusions are drawn from our simulation. Most of all, the diminution of information delay introduce monotonous growth rather than fluctuation of EC market. The stable increase of revenue or market scale makes us decide the employment or capacity scale quickly. Second, for favorable and continuous evolution of EC, utilization system of electronic money should be established steadily. The following findings strongly support our claim: We found full oscillation of EC market when electronic money system didn't established well. On the contrary, if electronic money system could provide fast cash flow and fully trustful function, decisions of company or consumer would be executed promptly.

• 한국습지학회지
• /
• 제20권2호
• /
• pp.124-130
• /
• 2018

본 연구는 무인모니터링 시스템을 활용하여 논에 도래하는 조류의 현황과 개체군 변동 특성을 확인하기 위해 수행되었다. 무인모니터링 시스템을 이용한 조사와 전문가에 의한 현장 조사를 비교하여 개체군 변동 특성의 유사성을 파악하였고, 무인모니터링 시스템 조사를 통해 확인된 조류의 개체군 변동을 시공간적으로 평가하였다. 무인모니터링 시스템을 활용한 조사는 철원, 당진, 부안, 해남 4곳에서 2014년 1월 1일부터 2016년 12월 31일까지 06:00부터 20:00까지 14시간 동안 10분 단위로 촬영하였다. 전문가에 의한 현장 조사는 2016년 1월부터 12월까지 당진에서 월 1회 수행되었다. 무인모니터링 시스템을 활용하여 조사기간 동안 한 대의 무인모니터링 시스템에서 총 91,980장의 이미지를 획득하였다. 획득한 이미지 자료를 분석하여 백로류, 도요물떼새류, 오리기러기류의 동정 및 개체군 변동을 확인하였다. 무인모니터링 시스템과 현장 조사를 비교해보면 수조류 군집 변동 패턴이 현장 조사 결과와 유사한 것을 확인 할 수 있었다. 특히 백로류의 개체군 변동의 유사성이 가장 높게 나타났다. 무인모니터링 시스템을 이용하여 지역별 백로류의 개체군 변동 특성을 확인한 결과 지역에 따라 개체군 변동 특성이 다르게 나타나는 것을 확인할 수 있었다. 또한 무인모니터링 시스템은 월 단위, 일 단위, 분 단위와 같이 다양한 시간 스케일에서 개체군 변동 특성을 확인 할 수 있는 장점을 가지는 것으로 나타났다. 무인모니터링 시스템을 이용한 장기적인 자료 축적은 논습지를 활용하는 수조류 군집의 세부적인 장기변동 특성뿐만 아니라 미래 예측에도 유용하게 이용될 것으로 기대된다.

• International Journal of Contents
• /
• 제14권4호
• /
• pp.86-91
• /
• 2018

Text has evolved along with the history of art as a means of communicating human intentions and emotions. In addition, text visualization artworks have been combined with the social form and contents of new media to produce social messages and related meanings. Recently, in text visualization artworks combined with digital media, communication forms with viewers are changing instantly and interactively, and viewers are actively participating in creating artworks by direct engagement. Interactive text visualization with additional viewer's interaction, generates external dynamics from text shapes and internal dynamics from embedded meanings of text. The purpose of this study is to propose a visual dynamics model to express the dynamics of text and to implement a text visualization system based on the model. It uses the deconstruction of the imaged text to create an interactive text visualization system that reacts to the gestures of the viewer in real time. Visual Transformation synchronized with the intentions of the viewer prevent the text from remaining in the interpretation of language symbols and extend the various meanings of the text. The visualized text in various forms shows visual dynamics that interpret the meaning according to the cultural background of the viewer.