• 대한기계학회논문집A
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• 제22권3호
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• pp.504-518
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• 1998

Degree-Of-Freedom(DOF) for most power transmission system varies according to the operation status which consists of friction elements to change the power flow or to adjust the speed ratio such as clutches, brakes or one-way clutches. To simulate the dynamic characteristics of automatic power transmission system which is a typical example of such a variable DOF systems, many sets of governing equations and complicated phase decision routines are necessary. In this paper dynamic constraint theorem is derived explaining the torque transmission characteristics during the clutch engagement process and a robust stable algorithm is developed describing this phase transition phenomenon effectively by introducing the concept of direct torque and virtual damping. Finally, applying this algorithm to a passenger car automatic transmission gear consisting of several friction elements, an efficient simulation methods for such a complex system will be suggested that is very simple and systematic.

• 한국군사과학기술학회지
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• 제21권4호
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• pp.551-561
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• 2018

Footprint is defined as ground area that is projected from the outer edges of the battle space protected by a defence system. This concept can be effectively used for making decisions on site selection of anti missile systems to defend against enemy's ballistic missiles. In this paper, simulations of ballistic missile trajectories based on various launch conditions are performed first and then the footprint is derived with engagement zone set as a boundary condition. Results of the simulation with various relative positions between the defense system and defended asset are also presented. The proposed method, in which the trajectories are generated based on launch point of the ballistic missile, has an advantage of approximating the defended area close to reality. Two applications are introduced in the present paper to describe how the derivation of defended area could be utilized in deployment decision of defense systems.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.577-585
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• 2012

Modeling & simulation-based battle experiments(BEx) is being used extensively as an efficient, scientific and rational verification methodology for maritime weapon system acquisition. However, research of definition and concept of BEx and standardized rules and process for the BEx are insufficient in recent military field of BEx. In this study, we discussed the definition and process of BEx based on the role of MND(including JCS), Navy and ADD and proposed the standardized process of BEx for maritime weapon system. Secondly suggested a evaluation methods of modeling and simulation-based BEx with MOP, MOF, MOE in linkage of engineering, engagement, mission and constructive model. Finally presented validate result that applied to the Torpedo using standardized process based on our proposed methodology.

• 한국시뮬레이션학회논문지
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• 제27권3호
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• pp.89-97
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• 2018

미래전에서는 무기체계의 상당부분이 무인체계로 대체될 것이며 이들은 상호 통신으로 연결되어 네트워크중심전으로 변화하고 있다. 이에 따라 무인체계 효과분석이 중요한 이슈가 될 것이다. 하지만 무인체계의 주요통제 수단인 통신장애 상황에서 UGV에 대한 효과분석 연구는 매우 미흡한 실정이다. 본 논문에서는 지형을 고려한 통신장애 상황에서 무인체계의 운용효과분석을 위한 새로운 에이전트기반 모델링 절차를 제시하였다. 추가적으로, 통신장애 상황을 극복할 수 있는 통신중계기를 추가하였을 경우 UGV운용효과의 변화에 대한 분석결과도 제시하였다.

• East Asian Economic Review
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• 제26권4호
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• pp.305-336
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• 2022

This study applied the macro-micro simulation model (i.e., what-if analysis) to investigate the impact of transport related to the Belt and Road Initiative (BRI) on poverty and income inequality in Laos. We selected Laos as a case study of a developing country. We used the standard GTAP model with the GTAP database (version 10) for the macrosimulation, whereas we used the household model with the latest Lao household data from 2019 for the microsimulation. Our findings revealed that the output of the Lao economy was anticipated to increase by up to 0.3%, while the poverty rate was anticipated to decline from 17.0% to 15.7%. However, there would be winners and losers in industries and groups of households in different areas. In particular, rich households with a comparative socioeconomic advantage, such as in education, engagement in nonfarm business, and infrastructure access, would mostly gain benefits; consequently, this would lead to higher inequality in Laos. Therefore, the inequality index (i.e., the Gini coefficient) would increase from 41.2 to 60.1. After a simulation of BRI transport, we also found that some nonpoor households, which are mainly associated with farm activities and lower educational levels, would fall into poverty.

• International Journal of Control, Automation, and Systems
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• 제3권3호
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• pp.486-492
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• 2005

A practical recursive WLS (weighted least squares) algorithm is proposed to estimate relative range using LOS (line-of-sight) information for ASM (anti-ship missile) application. Apart from the previous approaches based on the EKF (extended Kalman filter), to ensure good convergence properties in long range engagement situations, the proposed scheme utilizes LOS rate measurements instead of conventionally used LOS angle measurements. The estimation error property for the proposed filter is investigated and a simple error compensator is devised to enhance its estimation error performances. Simulation results indicate that the proposed filter produces very accurate range estimates with extremely small computations.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.175-186
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• 1996

In Advanced Vehicle Control System(AVCS), Autonomous Intelligent Cruise Control(AICC) is generally understood to be a system that can be achieved in the near future without the demanding infrastructure components and technoloties. AICC is an automatic vehicle following system with no human engagement in the longitudinal vehicle direction. This paper presents a fuzzy control algorithm to develop the AICC system. The control performance was studied information of vehicles using computer simulations. The most improtant aspects of the work reported here are the adoption of the fuzzy adaptive control law, and the use of filtering concept to reduce the slinky effects that may appear in a formation of vehicles equipped with AICC systems. The simulation results demonstrate the effectiveness of the fuzzy adaptive AICC system and its beneficial effects on traffic flow.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.469-474
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• 1990

The implementation of modern guidance law derived from optimal control theory requires accurate current states of target, for example, position, velocity and acceleration etc. But there is no sensors that measure the target states directly. So they are estimated from measurable data. For atmospheric missile engagement, direct application of the modern guidance laws may result In deterioration of Intercept performance because of poor observability associated with angles only-measurements by passive seeker and homing geometry. In this paper, a trajectory modulation method called "adaptive Intermittent maneuvers" is added to the modern guidance law, so the observability is enhanced and, consequently, improved the intercept performance. The estimation algorithm called "modified gain pseudo-measurement filter" is used for tracking filter. It is assumed that the passive seeker measure the angles between line of sight and Inertial frame. The Monte-Carlo simulation for realistic air-to-air Intercept scenario are conducted to demonstrate the effectiveness of intermittent maneuvers.ermittent maneuvers.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.106-116
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• 1997

In this paper, using MATLAB SIMULINK, a generalized design methodology was suggested for multi pass transmission(MPT) by classifying the vehicle power train as prime mover, MPT and vehicle dynamics. This approach enables a designer to investigate the influence of each transmission component by simple combination of system components without changes of overall program. Using the design methodology, a MPT consisting of CVT, 2, clutches and reduction gears was designed for a braking energy regenerative flywheel hybrid vehicle. The CVT is essential in order to connect the engine and flywheel speed with the vehicle speed. For the purpose of smooth clutch operation, control algorithm was suggested by introducing dead zone for the clutch engagement. Using the SIMULINK model, performance of the flywheel hybrid vehicle with MPT was investigated. It was observed from the simulation results that the MPT vehicle showed better fuel economy, 47% than that of AT vehicle, 27% than that of CVT vehicle for ECE-15 driving cycle. Especially destinct fuel efficiency improvement was obtained for city driving cycle requiring more frequent stop and start.

• 한국국방경영분석학회지
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• 제25권1호
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• pp.55-74
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• 1999

In this study, a nonsymmetric model of directional probability variation (dpv), which is fundamental and conforms well to various moving situations of attacking tanks, is obtained based on the Whittaker's theory. It is shown that it produces the same expression of the probability density function as the Whittaker's under the special moving condition of an attacking tank. Using the derived dpvs, the probability densities for the various cases of some examples are calculated numerically to verify the derived formulas, and compared with other existing symmetrical distributions widely used to grasp characteristics of them. As a result, it is noted that the plots of the probability density function for various cases selected exhibit very different and useful behavioral features. Applying the results with respect to the every tank in the computer simulation of engagement between two tank forces, it is expected that more reasonable shot distributions can be given comparing with other existing symmetrical ones. The derived dpvs may be utilized to decide shot distribution of other weapon systems through small modification.