• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.351-361
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• 2001

In this paper, a generalized framework called as robust internal-loop compensator(RIC) is presented, and by using this, a structural design method of sliding of sliding mode controller is proposed. First, a general sliding mode controller is derived and a stabilizing control input is designed based on Lyapunov redesign for the system in the presence of uncertainty and disturbance. And adopting the internal model following control, RIC is proposed. Next, using the structural characteristics of the proposed RIC, disturbance attenuation characteristics are analyzed and the performance of the closed-loop system is predicted. Through this analysis, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. the proposed method is verified through experiments using a high-precision positioning system and the performance is evaluated.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.795-802
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• 2020

This study seeks to determine the effect of the application of accounting information system (AIS), internal control system, and human resource (HR) competency on the quality of local government financial statements (FS). This study uses agency theory and compliance theory. Agency theory is used to explain that there is a link between the society as the principal and the government as the agent. Compliance theory is a theory, which states that every agency is obliged to comply with regulations because the law-drafting authority has the right to dictate behavior. The population in this study were employees of the financial division of local government organizations in one of the districts in Central Java, Indonesia. The total samples in this study was 106 respondents. The data used are primary data taken from distributing questionnaires to respondents. The method of analysis used to test the hypothesis was multiple linear regression analysis. The results of hypothesis testing indicate that HR competency has an effect on the quality of FS; however, the application of AIS and internal control system has no effect on the quality of FS. The implication of this research underlines the importance of HR competency to improve the quality of local government FS.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1077-1082
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• 2005

In this paper, it is proposed that the method for constituting pressure control system controlled by Direct Drive Valve (DDV). The DDV has a pressure-feedback-loop itself. It can eliminate non-linearity and uncertainty oi hydraulic system such as uncertain discharge coefficient and change of bulk-modulus. However, the internal feedback-loop can not compensate them perfectly. And fixed gain of the DDV's internal feedback-loop is not proper to apply it through wide pressure range. The steady state error and nonlinear characteristic of transient behaviour is observed in the experiment. So another controller is needed for the desirable performance of the system. To compose the controller, the pressure control system controlled by DDV is modeled mathematically and the parameters of the model are identified using signal-compression method. Then sliding mode controller is designed based on mathematical model. Desirable performance of the pressure control system controlled by DDV is obtained.

• Convergence Security Journal
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• v.12 no.3
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• pp.53-58
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• 2012

Network Access Control System that is one of the efforts to protect the information of internal applies to effectively control of insider and automatic network management and security. However, it has some problems : spoofing the authorized PC or mobile devices, connect to the internal network using a system that authorized users are away. In addition, information leakage due to malicious code in the same system. So in this paper, Network 2-Factor Access Control System based on RFID security control system is proposed for safety communication environment that performing a two-factor authentication using authorized user and devices to connect to the internal network.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.79-83
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• 2001

A cone-shaped active magnetic bearing spindle system for high speed internal grinding is designed and tested. The cone-shaped AMB system consists of only 4 couples of magnet, it can be smaller and lighter than conventional radial-axial-type AMB system. In this paper, the cone-shaped electromagnets are designed by magnetic circuit theory, and de-coupled direct feedback PID controller is applied to control the coupled magnetic bearings. The designed cone-shaped AMB spindle system is built and constructed with a digital control system, and tested its stbility and dynamic performances. As the results of the tests, this spindle runs up to 40,000 rpm with about 5 ${\mu}{\textrm}{m}$ of runout, and the AMB system provides high damping ratio eliminating overshoot and resonance speed.

• Management & Information Systems Review
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• v.30 no.3
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• pp.169-190
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• 2011

Recent academic studies have investigated book-tax differences as an indicator of earnings management. Tax accounting texts claim that the differences between pre-tax financial reporting earnings and taxable income can provide information about current earnings, and the large differences between book and taxable incomes are an indicator of low-quality financial reporting earnings. This study investigates the effect of internal control system over book and tax difference using the KOSPI and KOSDAQ firms from 2006 to 2008. The empirical findings are consistent with a weakness of internal control system being associated with higher book-tax difference. That means a firm which has material weakness in the internal control system allows for more malpractice. In addition to this, If the managers tries to the efficient tax decrease strategy, book-tax difference can be large. Which in turn leads us to observe a positive relation between the weakness of internal control system and intensity of book-tax difference. Overall, we interpret this evidence as indicating that the failure of the internal control system can effect not only investors and creditors but also tax authorities. And It emphasizes that a more effective internal control system linked with sound corporate governance.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.509-515
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• 2023

As the trend towards expanding the functions of modern governments continues, there are also problems such as misconduct and waste that arise as government activities and operations increase. To solve these issues, countries are establishing and developing internal control mechanisms. In this process, the U.S. Inspector General system has been operating for over 40 years with the aim of balancing and overseeing the government and the legislature. Accordingly, this study analyzed in detail the development process of the inspector system, one of the internal control systems promoted by U.S. government agencies, the formation of an inspector community, and the deployment, cooperation, and supervision of inspectors. As a result, the internal control system of domestic government agencies also needs to continue research so that the government and parliament can maintain close relations and introduce the inspector system according to the domestic situation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.175-185
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• 2002

In this paper, a new fully digital current control method of UPS inverter, which is based on an internal model control, is proposed. In the proposed control system, overshoots and oscillations due to the computation time-delay are compensated by explicit incorporation of the time-delay in the current control loop transfer function. The internal model controller is adopted to a second order deadbeat reference-to-output response which means that its response reaches the reference in two sampling time including computational time-delays. That is, the average current of filter capacitor is been exactly equal to the reference current with a time lag of two sampling intervals. Therefore, this method has an essentially overshoot free reference-to-output response with a minimum possible rise time. The effectiveness of the proposed control system has been verified by the simulation and experimental respectively. From the simulation and experimental results, the proposed system is achieved the robust characteristics to the calculation time delay and parameter variation as well as very fast dynamic performance, thus it can be effectively applied to the power supply for the critical load.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1944-1946
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• 1998

This paper presents a novel current control system to eliminate the steady state control error for PWM AC-DC converter. A general mathematical model of the converter which is represented as a state-space model is established. The state-space model is used for the simulation of converter with the proposed tracking control system of sinusoidal current. In this system, a novel current control which do not require coordinate transformations using internal principle of PI controller is described. It is proved that the steady state deviation reduce to zero through a transfer function of source current control system. Finally, simulations show good source current control characteristics by means of a simplified control system which do not require coordinate transformations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.281-284
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• 2004

This paper presents studies on the development of an internal measurement system for the footwear using laser sensor. The measurement system gains to the height of the profile at internal footwear. It accomplishes the 3-axises control which uses ball screws, L-M guides and stepping motors. It is used a laser sensor at the measurement of the distance, and Labview is used for the control and the measurement. We can get the profile through reverse engineering for the LAST. The data of profile is fixed a heigh of the LAST. Then, we try to verify as compare the profile with one which is collected by Internal measurement system..