• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.5
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• pp.29-38
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• 1998

This paper proposes the neural network self-tuning PID controller for the load frequency control of 2- areas power system, namely, the prompt convergence of frequency and tie-line power flow deviation. The neural network applied to computer simulation consists of neurons of two inputs, ten hiddens and tliree outputs layer. Neurons of two inputs layer receive the error and its change rate of the system and cutputs layer consists of three neurons for the parameters of the PID controller. The simulation results shows that the proposed neural network self-tuning PID controller is superior to conventional control t~:chniques(Optimal, PID) in dynamic response and control performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.101-105
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• 2002

In this paper, the coupling windows of the dielectric resonator filter have been analyzed. The coupling factor which has been used to characterize the coupling window is represented by closed form expressions. The deviation of the coupling factor as the size of coupling window has been compared between calculated by presented method and measured ones. There are very closed agreements. The presented method can be applied not only to design dielectric resonator but also to design varactor tuned dielectric resonator filter so as that the passband bandwidth is constant within tuned ranges.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.3
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• pp.378-385
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• 1998

A three-dimensional finite difference time domain (3-D FDTD) algorithm of calculation for the characteristics of coaxial-to-cavity filter including a discended probe and a tuning post is presented. In the arrangement the inner coaxial conductor protrudes into the cavity and operates as a probe radiator. And the height of the rectangular tuning post determines the resonant frequency. The validation of this method is confirmed by comparing the calculated values with experimental results for the designed filter.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.19-24
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• 2007

In this paper, we propose a tuning method of PID-PD controller to satisfy design specifications in frequency domain as well as time domain. The proposed tuning method of PID-PD controller consists of the convex set of PID and PI-PD controller. PID-PD controller controls the closed-loop response to be located between the step responses, and Bode magnitudes of closed-loop transfer functions controlled by PID and PI-PD controller. The controller is designed by the optimum tuning method to minimize the proposed specific cost function subject to sensor noise insensitivity and robust stability. Its effectiveness is examined by the case study and analysis.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1925-1926
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• 2008

본 논문에서는 UHF TV방송 전 대역 Ch.14(473MHz)$\sim$Ch.69(803MHz)까지의 모든 채널에서 동작하는 유도결합구조의 RF동조회로를 설계하였다. 기존 자기결합구조의 RF동조회로는 PCB 양면을 사용하여야 하고 수작업으로 Air Coil 간격을 조절해야만 한다. 부품의 집적화와 양산 효율성 측면에서 자기결합구조의 단점을 해결할 수 있도록 하기 위해 본 논문에서 제안한 유도결합구조는 수동부품인 칩인덕터와 칩커패시터 및 가변용량 다이오드만을 사용하여 RF동조회로를 설계하였다. 칩인덕터는 Air Coil에 비해 낮은 소자 Q값을 가진다. 상대적으로 낮은 Q값을 갖는 칩인덕터를 사용하기 때문에 이를 보완하기 위해 Peaking용 칩인덕터를 설계 디자인에 적용하였다. 가변형 대역통과필터로 동작하기 위해 자기결합구조와 동일하게 가변용량 다이오드를 이용하였다. UHF TV방송 전 대역(470$\sim$806MHz)에서 -2.88 $\sim$ -3.97dB의 삽입손실 특성 및 -8dB 이상의 반사손실 특성과 330MHz의 중심주파수 변화 범위를 갖는다. 현재 상용중인 지상파 튜너에 적용되고 있는 자기결합구조의 RF동조회로를 대치하여 적용될 수 있을 것이다.

• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.80-87
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• 2002

In this papers, It was researched Automatic frequency detection which need using ultrasonic utmost effort. As far as ultrasonic Automatic frequency detection, It was analog method, In more dedicated field, to solve a limit. It was needed a new method detection instrument.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.5
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• pp.20-25
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• 1982

A realization method of the microwave oscillator is proposed by the inherently stable transistor with a cavily resonator feedback loop. The real Part of the output impedance of the inherently stable bipolar transistor can be made to be negative at the resonance frequency by the high-Q cavity feedback loop, and the oscillation condition can be obtained with the matching section of the load. In this work the microwave transistor oscillator is realized with a silicon bipolar transistor HXTR 2101 and a reentrani cavity, and characteristic of the output power 10m Watts at 2.33 GHz osc. frequency can be verified experimentally.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.271-272
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• 2011

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.211-220
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• 2001

This paper proposes a 2-D texture segmentation algorithm which is in close analogy to amplitude demodulation in communication systems. First, we show that it is theoretically possible to segment a multitexture image using an ideal filter followed by an amplitude demodulation block. However, in practice, the Gabor filter is used instead of the ideal filter because it has many desirable properties and especially it gives optimum space-bandwidth product. Our algorithm recovers all the texture regions containing the sinusoid with frequency to which the Gabor filter is tuned. We have demonstrated the discriminating power of our method in using a synthetic multitexture image. It is clear mathematically and easy to implement. Our method can be a good alternative to avoid many problems encountered in classifying the feature vectors in feature-based texture segmentation approaches.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.234-236
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• 2009

종래의 음향기기에서 소리 크기는 각 주파수별로 다른 감도를 갖는 개인의 주파수 청력 특성을 고려하지 않고 모든 주파수에 대하여 동일하게 선형으로 소리 크기를 조절한다. 따라서 감도가 높은 주파수대에서 청력 손상을 일으킨다. 이를 개선하기 위한 표준 청력특성, ISO266:2003 표준을 이용한 평활화 방법이 있지만, 이 표준에 따른 등청감곡선은 여러 사람에 대해 평균한 청력특성이기 때문에 다양한 환경에 의해 변형된 개인별 청력특성에 맞지 않아 청력 손상을 감소시키는 실질적인 효과가 저하되는 문제점이 있다. 본 연구는 사람마다 다른 최소가청한계 특성을 갖는 청각특성과 최대가청한계를 고려하여 소리 크기를 조절함으로써 음향기기에 의한 청각 손상을 감소시키는 방법에 관한 것이다. 컴퓨터 시뮬레이션을 통해 청력 특성이 좋은 대역에서 기존 방법에 비해 보다 낮은 소리 크기에서 불편없이 인지 가능하다는 것을 확인할 수 있었으며, 동시에 과도한 대역별 소리 에너지를 줄여 청각 손상도 방지할 수 있다는 것을 확인할 수 있었다.