• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1788-1791
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• 1997

In this paper constant-level luffing and time optimal control of a JIB crane is investigated. The crane is assumed to have only the derricking motion. the analysis of plance kinematics provides the relationship between the boom angle and the main hosit motor angle for constant-level luffing. The dynamic equations for the crane are very nonlimear, and therefore they are linearized for the application of the linear control theory. The time optimal control in the perspective of no-sway at the end of boom stroke is investigated.

• 한국시스템다이내믹스연구
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• 제15권4호
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• pp.129-159
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• 2014

This Study discuss exploring normative-prescriptive factors after the themes on Organizational learning categorize two descriptive/explanatory-perspectives, prescriptive/normative dimension. The former would contain information processing model, theory of action, organizing in organization, while Senge's suggestion on Learning Organization may compose the latter. Each perspective is reconstructed and reinterpreted into the causal mapping relationship founded on system thinking and SD. Underlying on the former try to discovery validities of the latter. But this study only put forward the integral-dynamic model of organizational learning without empirical simulation.

• 한국시스템다이내믹스연구
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• 제3권1호
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• pp.61-77
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• 2002

This paper reviews issues and methodological status of system dynamics and suggest some research agenda for its development in Korea. After reviewing some characteristics of system dynamics approach, including dynamic feedback perspective and endogenous point of view, the paper pointed out methodological characteristics of system dynamics. It seems to be the most notable characteristics of System Dynamics that it use both quantitative and qualitative approach in explaining and modelling reality. Besides, System Dynamicists rely more heavily on refutationism than instrumentalism and this allows System Dynamicists follow more strict way of scientific inquiry. For the development of System Dynamics in Korean academic circle, developing training program and curriculum, networking scattered System Dynamicist all over the country, would be the most important task.

• Communications for Statistical Applications and Methods
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• 제21권5호
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• pp.445-459
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• 2014

This paper investigates the dependence structure of Korean financial markets (stock, foreign exchange (FX) rates and bond) using copula-GARCH and dynamic conditional correlation (DCC) models. We examine GJR-GARCH with skewed elliptical distributions and four copulas (Gaussian, Student's t, Clayton and Gumbel) to model dependence among returns, and then employ DCC model to describe system-wide correlation dynamics. We analyze the daily returns of KOSPI, FX (WON/USD) and KRX bond index (Gross Price Index) from $2^{nd}$ May 2006 to $30^{th}$ June 2014 with 2,063 observations. Empirical result shows that there is significant asymmetry and fat-tail of individual return, and strong tail-dependence among returns, especially between KOSPI and FX returns, during the 2008 Global Financial Crisis period. Focused only on recent 30 months, we find that the correlation between stock and bond markets shows dramatic increase, and system-wide correlation wanders around zero, which possibly indicates market tranquility from a systemic perspective.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.49-52
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• 1996

In this article, we develop a 'dynamic' approach to manufacturing improvement, based on perspectives of manufacturing learning and decision theory. First, we present an alternative definition of production system consistent with a decision-theoretic perspective: the system consists of structural, infra-structural, and decision making constructs. A primary proposition is that learning capability possessed by a manufacturing system be prerequisite for the system to improve its manufacturing performance through optimal controlling of the three constructs. To support the proposition, we elaborate on a mathematical representation of "learning" as defined in an applied setting. We show how the learning capability acts as an integrating force ameliorating the trade-off between two key manufacturing capabilities, i.e., process controllability and process flexibility.exibility.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.379-386
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• 2007

Recently the concrete slab tracks are being constructed on roadbed in the Kyong-bu 2nd stage high speed railways. In responding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides the design standards and the maintenance system. The proposed standards and the maintenance system are based on the track theory and the track-train interaction program developed, where the roadbed displacement and train speed are utilized as mediating variables. In the analysis, the dynamic response of track-train interaction apply to various speeds and displacements. the roadbed displacement is shown in a sine curve, the scope of the displacement occurrence, presented in its wavelenths, include 6meters, 10meters, 15meters, 20meters, 30meters. the train speeds involved are 50,100, 150,200,250,300,350,400 kilometers per hour.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권1호
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• pp.51-62
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• 2008

This paper proposes a second-order implicit constraint enforcement method which yields enhanced controllability compared to a first-order implicit constraints enforcement method. Although the proposed method requires solving a linear system twice, it yields superior accuracy from the constraints error perspective and guarantees the precise and natural movement of objects, in contrast to the first-order method. Thus, the proposed method is the most suitable for exact prediction simulations. This paper describes the numerical formulation of second-order implicit constraints enforcement. To prove its superiority, the proposed method is compared with the firstorder method using a simple two-link simulation. In this paper, there is a reasonable discussion about the comparison of constraints error and the analysis of dynamic behavior using kinetic energy and potential energy.

• Asian Journal of Business Environment
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• 제5권4호
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• pp.67-72
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• 2015

Purpose - This aim of this study is to examine how conglomerates in Korea have evolved from the perspective of institutional economics. The growth of the economy, dominated by large conglomerates, is projected in light of the dynamic equilibrium between government and capitalists. Research design, data, and methodology - The historical formation of big business groups is examined in chronological order. For the analysis, we divide the assessment into three different eras: Japanese colonial rule, liberation up to the civil war, and the fast growing period since the military coup. Each period is viewed as a dynamic equilibrium that is shaped by economic agents. Results and Conclusion - Despite the rise of modern commerce during the colonial era, contemporary conglomerates came into being with the "enemy property" allotted by the government. Around the civil war, the government coexisted with prototype conglomerates through foreign aid. As the external aid decreased, the system could not be sustained anymore, thus the military coup took place. The reinstated strong bond between government and the conglomerates has shaped the forms of the modern conglomerates thereafter.

• Interaction and multiscale mechanics
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• 제3권2호
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• pp.111-121
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• 2010

Dynamic analysis of nano/micro bio-sensors based on a multiscale atomistic/continuum theory is introduced. We use a generalized atomistic finite element method (GAFEM) to analyze a bio-sensor which has $3{\times}N_a{\times}N_p$ degrees of freedom, where $N_p$ is the number of representative unit cells and $N_a$ is the number of atoms per unit cell. The stiffness matrix is derived from interatomic potential between pairs of atoms. This work contains two studies: (1) the resonance analysis of nano bio-sensors with different amount of target analyte and (2) the dependence of resonance frequency on finite element mesh. We also examine the Courant-Friedrichs-Lewy (CFL) condition based on the highest resonance frequency. The CFL condition is the criterion for the time step used in the dynamic analysis by GAFEM. Our studies can be utilized to predict the performance of micro/nano bio-sensors from atomistic perspective.

• 드라이브 ㆍ 컨트롤
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• 제20권1호
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• pp.27-33
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• 2023

From the perspective of dental chair manufacturers, it is important to of localizing hydraulic system in order to secure market competitiveness. This study aims to develop the analysis model of a dental chair which overseas companies secure core technologies. The study follows the steps below. First, the component parts of the solenoid valve unit of a foreign leading company are analyzed and implemented in virtual environment. Second, dynamic behavior scenario is established based on solenoid valve signal chart provided by a foreign leading company. The analysis model is verified and its performance is analyzed using dynamic behavior according to each scenario. Third, a simulation is carried out to determine whether the cylinder velocity of designed hydraulic system surpasses 1cm/s as required by the design.