• Proceedings of the KIEE Conference
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• summer
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• pp.563-565
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• 2004

It is expected to reduce stresses to components of high voltage circuit breaker and transferred switching surge from power system by applying controlled switching technique to high voltage system. This technique has at ready been applied in advanced countries. In this paper, basic principle of controlled switching technique is set up and a device to realize this technique is under developing. Controlled switching device will be improved by applying a method minimizing errors of operating time and by adopting compensation function relative to changes of ambient/operating condition.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.270-276
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• 2002

An integrated robust fault diagnosis and fault accommodation strategy for a class of linear stochastic systems subjected to unknown disturbances is presented under the assumption that only a single fault may occur at a given time. The strategy is based on the fault isolation and estimation using a bank of robust two-stage Kalman filters and introduction of the additive compensation input for cancelling out the fault's effect on the system. Each filter is set up such that the residual is decoupled from unknown disturbances and fault with the influence vector designed in the filter. Simulation results for the simplified longitudinal flight control system with parameter uncertainties, process and sensor noises demonstrate the effectiveness of the present approach.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.9
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• pp.361-367
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• 1985

A new injection method is proposed for active power filters to eliminate AC harmonics in ac input current of nonlinear loads such as rectifiers. By injecting the PWM current determined by the proposed injection method, all the harmonics up to order nn can be eliminated to exactly zero. This PWM injection current can be generated by sampling total harmonic wave at the rate of M and the sampled values are converted into the proposed PWM wave with N pulse-width variables and adjustable current magnitude Im. These variables are deetermined by solving a set of N nonlinear harmonic equations and the harmonic-elimination characteristics of the new injection are investigated through digital computer sinmulation. Also by comparing between the simulated results and the ones synthesized by data stored in EPROM, the possibility of the suggested injection method can be shown.

• Journal of Digital Convergence
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• v.2 no.1
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• pp.113-126
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• 2004

In this paper we would like to provide a help to implementing KMS(Knowledge Management System) in public sector. For this purpose, we set up five contingency environmental factors and three process factors of knowledge management. And then investigates affecting factors effect on the performance of KMS in public sector by empirical study, A field survey of public officers in Korea local government was conducted. Complete data for 333 KMS users was analyzed to determine relationship of the research constructs. The system of evaluation and compensation is the most important factor effects on the process of KM and the performance of KMS. These results provide empirical evidence that supports the necessity of rational motivation systems does lead to effective implementation of KMS in public sector.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.596-599
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• 2000

A natural admittance control system design is presented for a particular type of interaction controller that achieve high-performance and guarantees stability. The admittance control Significantly improves performance when Coulomb friction is present in the one link robot system. The technique requires a careful choice of the target impedance. Experimental performance results are presented for a two-mass system with internal Coulomb friction. Results demonstrate that the admittance control law is successful in rejecting internal Coulomb friction force disturbances. The controller was designed and implemented on our system that we set up one link robot system and hardware configuration system, and performance results are presented.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2146-2148
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• 2003

This paper present a modified repetitive control scheme for an optical storage system to track a periodic reference signal with dynamic change in period. Periodic disturbances can be adequately attenuated using the concept of repetitive control, provided the period is know. An optical storage system supports various speeds. To deal with time varying periodic disturbances, an proposed repetitive controller is turned based on repetitive control to change sampling frequency to follow the change of reference Period. A modified repetitive control scheme is proposed and implement on experimental set up of a optical disk driver.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.31-36
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• 2011

Smart Door(SD) is a human friendly power-assisted door system for passenger car doors. It offers comfort and safety to passengers and drivers by supplying additional power. In this study, dynamic system model and the equation of motion derivation are derived. And we propose the disturbance observer based collision detection algorithm for safety when opening the door. A disturbance caused by collision has a fast response compared to a friction, uncertainties and so on. The main idea this study is to estimate a variation of disturbance for stably and effectively detecting a collision. In order to evaluate a performance of collision detection, an experiment set up is constructed. The experimental results validate the usefulness of the proposed collision detection algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.1
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• pp.11-19
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• 2011

This paper describe development of a hardware simulator for the DFIG wind power system, which was designed considering wind characteristic, blade characteristic, and blade inertia compensation. The simulator consists of three major parts, such as wind turbine model using induction motor, doubly-fed induction generator, converter-inverter set. and control system. The turbine simulator generates torque and speed signals for a specific wind turbine with respect to the given wind speed which is detected by Anemometer. This torque and speed signals are scaled down to fit the input of 3.5kW DFIG. The MSC operates to track the maximum power point, and the GSC controls the active and reactive power supplied to the grid. The operational feasibility was verified through computer simulations with PSCAD/EMTDC. And the implementation feasibility was confirmed through experimental works with a hardware set-up.

• 한국항공우주법학회:학술대회논문집
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• 2008.05a
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• pp.121-140
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• 2008

Most compensation issues are regulated under domestic law where third parties are suffered damage from crushes of aircrafts or their falling objects. This issue was internationally recognized. A Convention to unify the rules of the law concerning damage caused by aircraft to the third parties on the surface was signed in May,1933( the 1933 Rome Convention) and it became effective in 1942. Later, modernization was carried out through the 1952 Rome Convention and the 1978 Montreal Protocol amending the 1933 Rome Convention. Ratifying States either to the Convention or to the Protocol is not as many as those States to the Warsaw Convention concerning air transport. In 1999, which was a turning point of changes of centuries from the twentieth century to the twenty first century, the Montreal Convention was passed to modernize the Warsaw Convention, and was quickly widespread. On September 11 2001, the coordinated simultaneous terror attacks occurred. In the circumstances, the issue modernizing the Rome Convention came up. Thus, workout under the initiatives of the Legal Committee of the ICAO is under operation to adopt new Rome Convention. In Japan, a study on the draft of the treaty was operated by which a working study group composed of experts from academy, industry and government was set up. This article, being based on that study, clarifies issues and gives future perspectives. This article presents author's individual views.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.1
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• pp.55-81
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• 2008

Most compensation issues are regulated under domestic law where third parties are suffered damage from crushes of aircrafts or their falling objects. This issue was internationally recognized. A Convention to unify the rules of the law concerning damage caused by aircraft to the third parties on the surface was signed in May, 1933( the 1933 Rome Convention) and it became effective in 1942. Later, modernization was carried out through the 1952 Rome Convention and the 1978 Montreal Protocol amending the 1933 Rome Convention. Ratifying States either to the Convention or to the Protocol is not as many as those States to the Warsaw Convention concerning air-transport. In 1999, which was a turning point of changes of centuries from the twentieth century to the twenty first century, the Montreal Convention was passed to modernize the Warsaw Convention, and was quickly widespread. On September 11 2001, the coordinated simultaneous terror attacks occurred. In the circumstances, the issue modernizing the Rome Convention came up. Thus, workout under the initiatives of the Legal Committee of the ICAO is under operation to adopt new Rome Convention. In Japan, a study on the ICAO Draft Convention was operated by which a working study group composed of experts from academy, industry and government was set up. This article, being based on that study, clarifies issues and gives future perspectives. This article presents author's individual views.