• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.81-85
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• 2010

This paper deals with the issue of motion control of a single rod cylinder-load system using simple adaptive control (SAC) method. Prior to controller design, the experiment of open-loop response has been performed. Based on it, design parameters of transfer function are obtained. The effect of parallel feedforward compensator has been investigated by computer simulation, suppressing the oscillatory motion. Through experiments it is conformed that the SAC method gives good tracking performance compared to the PD control method.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.185-189
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• 1998

This paper addresses analysis and design of a fuzzy model-based-controller for the control of uncertain SISO nonlinear systems. In the design procedure, we represent the nonlinear system by using a Takagi-Sugeno fuzzy model and construct a global fuzzy logic controller via parallel distributed compensation and sliding mode control. Unlike other parallel distributed controllers, this globally stable fuzzy controller is designed without finding a common positive definite matrix for a set of Lyapunov equations, and has good tracking performance. The stability analysis is conducted not for the fuzzy model but for the real underlying nonlinear system. Furthermore, the proposed method can be applied to partially known uncertain nonlinear systems. A numerical simulation is performed for the control of an inverted pendulum, to show the effectiveness and feasibility of the proposed fuzzy control method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.7
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• pp.619-625
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• 2004

Direct velocity feedback (DVFB) control is known that it offers an unconditional stability with very high performance when the control strategy is applied at a point collocated sensor and actuator pair. because the sensor-actuator pair has strictly positive real (SPR) property In this paper, two types of collocated sensor-actuator pairs are considered for practical active vibration control of a structure. They are a Point collocated sensor-actuator pair and a point sensor-distributed actuator pair. Both pairs with DVFB show robust stability and performance. It is noted that the collocated point sensor-actuator ultimately acts as a “skyhook” damper, hut the point sensor-distributed actuator pair with DVFB acts as a “skyhook” rotational damper pair.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.239-242
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• 1996

A model following control system(MFCS) can give general output signals following desired ones. In previous studies, a method of nonlinear MFCS was proposed by S.Okubo[1]. In this paper, the method of nonlinear MFCS will be extended to discrete time nonlinear systems. It is easy to extend the method to discrete time systems. But in the case .gamma.=1 discrete time systems, the proof becomes difficult, because the transfer function from f(v(k)) to v(k) can't be a positive real function. In this case, to ensure that internal states are stable, a new criterion is proposed.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.2
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• pp.23-28
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• 2011

This paper investigates the motion control of a hydraulic motor-load system using the Simple Adaptive Control (SAC) method. The plant transfer function has been modelled mathematically. The open-loop responses have been obtained experimentally in order to identify the design parameters of transfer function. The hydraulic motor-load system has been modelled using the 3D CAD and imbedded in the hydraulic circuit simulation program to verify the overall performance. The experimental results confirm that the SAC method gives a good tracking performance compared to the PID control.

• Journal of Korean Institute of Industrial Engineers
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• v.38 no.2
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• pp.144-156
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• 2012

In recent years, advanced countries in energy sector are emphasizing the importance of the development and deployment of renewable energy to cope with the global environmental crisis such as depletion of fossil energy, climate convention to control emissions of greenhouse gases. In this paper, we evaluate the economic value of the investment in new and renewable energy R&D in Korea and optimal deployment timing of new and renewable energy by using the real option approach. The real option model adopted in this paper assumes that a decision maker has a compound option to abandon, deployment, or continue the R&D. As a result by using empirical data of Korea, it is found that there exists a considerable amount of positive real option value (ROV) in the investment of new and renewable energy R&D while its net present value (NPV) calculated by traditional discounted cash flow (DCF) model shows negative value.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.569-573
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• 2010

A quantitative detection method for Salmonella in seafood was developed using a SYBR Green-based real-time PCR assay. The assay was developed using pure Salmonella DNA at different dilution levels [i.e., 1,000 to 2 genome equivalents (GE)]. The sensitivity of the real-time assay for Salmonella in seeded seafood samples was determined, and the minimum detection level was 20 CFU/g, whereas a detection level of 2 CFU/ml was obtained for pure culture in water with an efficiency of ${\geq}85%$. The real-time assay was evaluated in repeated experiments with seeded seafood samples and the regression coefficient ($R^2$) values were calculated. The performance of the real-time assay was further assessed with naturally contaminated seafood samples, where 4 out of 9 seafood samples tested positive for Salmonella and harbored cells <100 GE/g, which were not detected by direct plating on Salmonella Chromagar media. Thus, the method developed here will be useful for the rapid quantification of Salmonella in seafood, as the assay can be completed within 2-3 h. In addition, with the ability to detect a low number of Salmonella cells in seafood, this proposed method can be used to generate quantitative data on Salmonella in seafood, facilitating the implementation of control measures for Salmonella contamination in seafood at harvest and post-harvest levels.

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.27-32
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• 1997

This paper presents an H\ulcorner controller design method for linear time-invariant systems with delayed state and control. Using the second method of Lyapunov, the stability for delayed systems is discussed. For delayed systems, we derive a sufficient condition of the bounded real lemma(BRL) which is similar to GBRL for nondelayed systems. And the sufficent conditions for the existence of an H\ulcorner controller of any order are given in terms of three linear matrix inequalities(LMIs). Further, we briefly explain how to construct such controllers from the positive definite solutions of their LMIs and gie a simple example to illustrate the validity of the proposed design procedure.

• Journal of the Korean Data and Information Science Society
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• v.7 no.1
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• pp.69-78
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• 1996

Consider a natural model for stochastic flow systems is Brownian motion, which is Brownian motion on the positive real line with constant drift and constant diffusion coefficient, modified by an impenetrable reflecting barrier at $x_{0}$. In this paper, we investigate the joint distribution functions and study on the distribution of the first-passage time. Also we find out the distribution of ${\mu}-RBMPx_{0}$.

• The Journal of Industrial Distribution & Business
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• v.9 no.9
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• pp.7-14
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• 2018

Purpose - Social welfare is a social insurance system that provides funds and services for all citizens to maximize their life quality. Its ultimate goal is to alleviate social contradictions. Therefore, this paper explores the determinants of social welfare in terms of macroeconomics. Research design, data, and methodology - Based on the vector error correction model, the annual time series from 1990 to 2017 will be used to conduct an empirical analysis. The real GDP, the real income, the inflation and the degree of openness will be treated as independent variables. The input of social welfare will be treated as a dependent variable. These variables will be used to perform the cointegration test and the vector error correction model to explore how the macroeconomic variables affect social welfare both in long run and short run. Result - Via the empirical analysis, it can be summarized that the real GDP, the real income and the degree of openness are the driving determinants to enlarge the social welfare. Conversely, the inflation is the obstructive determinant to reduce the social welfare. Conclusion - The positive and negative determinants of social welfare exist simultaneously, China's government should take macroeconomic regulation and control to balance them to enlarge social welfare.