• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.10
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• pp.48-53
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• 1994

The problem of a plane wave impinging upon a semi-infinite paralle-plate waveguide is investigated. The interior fields can be analyzed by converting the initial field into vaveguide modes. Kirchhoff approximation is usually made at the waveguide aperture in the literature. In this paper, a modified approximation is made using the Uniform Gemetrical Theory of Diffraction(UTD). Numerical results show excellent agreement between UTD-supplemented mode-matching solution and UTD solution.

• Speech Sciences
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• v.8 no.2
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• pp.83-90
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• 2001

We proposed a probabilistic approach of using syllable bigrams to the word-spacing problem. Syllable bigrams are extracted and the frequencies are calculated for the large corpus of 12 million words. Based on the syllable bigrams, we performed three experiments: (1) automatic word-spacing, (2) detection and correction of word-spacing errors for spelling checker, and (3) automatic insertion of a space at the end of line in the character recognition system. Experimental results show that the accuracy ratios are 97.7 percent, 82.1 percent, and 90.5%, respectively.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.355-359
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• 1989

An inverted pendulum is made practically and controlled by optimal controller and pole placement controller. An IBM PC/XT plays a part of the controller. The control algorithm is implemented with C language. An integrator is added to the controller to solve the high frequency problem. Experiment is performed according to the results of simulation.

• 전기의세계
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• v.29 no.5
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• pp.329-335
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• 1980

This paper presents the reliability calculation method in power supply for a part of the power system reliability control. This method involves assuming several systems that can meet the demands, accidents on the transmission facilities and power source and performing the load flow calculation which will lead to the demands which are not served, frequency of the not-served demands and mean value of the not-served demands. In this study the simplified method for reliability calculation by using the maximal flow problem was developed. The results demonstrate the remarkable advantages and more useful than any other methods for the practical applications.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1195-1196
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• 2008

It is difficult to solve PCB(Printed Circuit Board) Noise problem. Because Electronic circuit system operates very high frequency. Resonance analysis of PCB layout by PI(Power Integrity) Simulation method visualizes distribution of Switching noise between VDD and GND. By using de-cap, we reduce impedance and solve the EMI problems.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.753-758
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• 1988

In this paper, we propose a new method of designing a reduced-order controller for a linear discrete-time system. Firstly, we study a design problem for a two-degree-of-freedom control system with a feedforward controller. Secondly, in order to obtain a reduced-order controller, frequency-weighted least squares approximation problems are considered. Thirdly, we propose a synthesis procedure of a reduced-order controller. Finally, an example is given to illustrate the effectiveness of this proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.385.1-385
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• 2002

Operational Modal Analysis also known as Ambient Modal Analysis has an increasing interest in mechanical cngineering. Especially on big structures where the excitation and not less important the determination of the forces is most often a problem. In a structure like a wind turbine wing where the modes occur both close in frequency and bi-directional the Ambient excitation has big advantages. (omitted)

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.435-444
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• 2001

In the Korea, railroad accidents result in about 5.4 railroad run-off crashes every year and account for approximately 93 percent of all railroad accident frequency. Despite the number, quantification of the possible countermeasure has been limited and also railroad safety control after private management for railroad has not been established. Therefore, this study provides some initial insight into the important safety problem by introducing some example, including some detailed safety regulations in both British and U.S. to develop appropriate railroad safety management system.

• Journal of KSNVE
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• v.2 no.3
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• pp.223-230
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• 1992

Vibration problems in the Hard Disk Drive which is magnetic recording device have been raised gradually while HDD is required high density and low access time. As a typical thing, lateral bending or sway mode of supension causes tracking error, and therefore it is necessary to identify the accurate vibration characteristics of that mode. In this study, as the solution of vibration problem, decoupling sway mode and vicinity mode is dealt with. Shifting sway mode to high frequency region is studied.

• Journal of the Korean housing association
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• v.4 no.1
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• pp.39-46
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• 1993

The purpose of this study is to find the problem of housing management through the investigation of agent of apartment house management. Therefore this study to providing reasonable information that can help the Government and management stafft deal with the provlems in apartement house. For the purpose of this study, qusetionaire consists of the contents for works of management and attitude of management staff about it. Qusetionaires were administered to 120 management staff in Ulsan, Pusan. 120 data was analized by the SPSS+ PC. The statistics used were frequency, mean, corelation.