• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06b
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• pp.45-50
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• 1999

이진 영상의 압축은 디지털 도서관, 팩시밀리 전송, 문서 입출력 시스템과 같이 한정된 대역폭과 저장 공간을 가진 응용 분야에서 절실히 요구되고 있다. 현재 많은 영상 압축 알고리즘이 채택하고 있는 대역분할 기법을 문서와 같은 이진 영상의 압축에 적용한다면, 점진적 전송, 축소영상을 통한 빠른 검색 등의 장점을 얻을 수 있다. 그러나, 이진 영상 신호가 두 단계의 휘도 값을 가지므로, 이에 적합한 대역분할 방법과 산술부호기를 선택하여야 한다. 본 논문에서는 표본화-XOR 대역분할 기법을 선택하여, 알파벳 수의 증가를 막고 공간영역에서 국부적인 성질을 얻을 수 있다 또한, 넓은 단일-색 영역을 Zerotree로 대표하여 부호화 되는 신호의 수를 줄이고, 대역분할 구조에서 예측성의 저하를 막기 위한 적절한 조건화문맥과 새로운 부호를 선택한다. 이진 영상에 적합한 대역분할 방법과 산술부호기를 선택하여, 대역분할의 장점과 우수한 압축 성능을 달성할 수 있다.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.224-229
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• 2003

We realized a depolarizer based on two 2$\times$2 directional couplers and single mode optical fiber. A reduction method for the degree of polarization is demonstrated by using computer simulation, which is verified experimentally. The degree of polarization is -20 dB for the polarized input beam of spectral width less than 0.05 nm. The experimental results verify that the polarization noise, which is due to the change of the input polarization state, can be reduced by making the fiber-ring delay-line length greater thanthecoherencelengthofthesource.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.906-911
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• 2004

In this paper, a VCDRO(Voltage Control Dielectric Resonator Oscillator) applied to FMCW(Frequency Modulated Continuous Wave)Radar as stable source is implemented and constructed with a MESFET(Metal-semiconductor Field-Effect Transistor) for low noise, a dielectric resonate. of high frequency selectivity, and high Q varator diode to obtain a good phase noise performance and stable sweep characteristics. The designed circuits is simulated thrash harmonic balance simulation technique to provide the optimum performance. The measured result of a fabricated VCDRO shows that output is 2.22㏈m at 12.05GHz, harmonic suppression -30㏈c, phase noise -130㏈c at 100KHz offset, and sweep range of varator diode $\pm$18.7MHz, respectively. This oscillator will be available to FMCW Radar.

• Fire Science and Engineering
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• v.23 no.2
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• pp.1-5
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• 2009

We studies wish to investigated establishment form of cabinet board, and confirm possibility of electrical disaster prevention through reappearance experiment of odor detection system. Established breaker consists of MCCB, RCD order in cabinet board for house, but industry is used together with. When imposed shock using shaker to terminal block that contact becomes in appropriate, flame was made sure. According to result that experiment attaching odor capsule in terminal block, capsule commissioned exactly by occurred heat. According to establishment position of sensor, difference of inspection time was about 10 seconds. Estimate odor inspection system by thing which electrical device accident prevention is available. When there is abnormal generated heat in connection of electric wire, accident prevention estimates that is possible by giving an alarm state of overheat to administrator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.6
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• pp.485-493
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• 1990

Timing recovery for recently proposed nonlinear minimum-bandwidth systems is of concern since most conventional methods fail for these systems. As a method to surmount this retiming difficulty, this paper proposes the fourth-power-law method. The feasibility of the proposed method for minimum-bandwidth systems is shown through a rigorous analysis. Furthermore, extensive computer simulations are used to determine the best configurational strategy for various filters around the fourth-power nonlinear process. It is found that no intermediate filtering is necessary in general and even the pre-filtering can be omitted for systems having symmetric power spectral densities.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.327-336
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• 2007

Lots of effort toward design optimizations have been paid for a cost-effective system design in various ways from a transistor level to RTL designs. In this paper, we propose a bit level optimization of an adder design for expanding its design space. For the bit-level optimization, a heterogeneous adder organization utilizing a mixture of carry propagation schemes is proposed to design a delay-area efficient adder which were not available in an ordinary design space. Then, we develop an optimization method based on Integer Linear Programming to search the expanded design space of the heterogeneous adder. The novelty of the Proposed architecture and optimization method is introducing a bit level reconstruction/recombination of IPs which have same functionality but different speed and area characteristics for producing more find-grained delay-area optimization.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.6
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• pp.1-10
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• 2007

This paper presents a direct nonlinear multivariable self-tuning PID controller using neural network which adapts to the changing parameters of the nonlinear multivariable system with noises and time delays. The nonlinear multivariable system is divided linear part and nonlinear part. The linear controller are used the self-tuning PID controller that can combine the simple structure of a PID controllers with the characteristics of a self-tuning controller, which can adapt to changes in the environment. The linear controller parameters are obtained by the recursive least square. And the nonlinear controller parameters are achieved the through the Back-propagation neural network. In order to demonstrate the effectiveness of the proposed algorithm, the computer simulation results are presented to adapt the nonlinear multivariable system with noises and time delays and with changed system parameter after a constant time. The proposed PID type nonlinear multivariable self-tuning method using neural network is effective compared with the conventional direct multivariable adaptive controller using neural network.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.878-879
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• 1997

본 논문에서는 전자기 과도현상 해석을 위한 다단자 회로망 등가표현법을 제안한다. 이 방법은 M개의 경계모선을 가진 축약대상 계통의 과도특성을 시간 영역에서 분석하며 이를 이용해 M 개의 노톤형 이산시간 등가 어드미턴스 필터꼴의 등가시스템을 구현한다. 이 때 각각의 등가 어드미턴스 필터 모델들은 해당 경계모선에서의 구동점 어드미턴스 특성을 나타내는 부분과 나머지 M-1 개의 등가 종속전류원으로 구성된다. 또한 이 등가 종속전류원들은 각 경계모선을 연결하는 분포정수 회로요소들로 인한 시지연 효과를 명확하게 반영할 수 있는 구조를 갖는다. 완성된 M 단자쌍 모델을 해석대상 시스템에 대한 이산시간 표현형과 쉽게 결합하여 원하는 전자기 과도현상 모의해석을 수행할 수 있다. 축약대상 시스템과 2 개의 경계모선을 통해 연결된 시험계통을 대상으로 모선지락 사고시 과전압과 스위칭 써지를 모의해석한 결과 제안하는 방법이 타당함을 확인할 수 있었다.

• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.143-147
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• 2014

In this paper, a novel MDI(Multiplex Distribution Interface) analyzer is designed in Ethernet-mode for DRM(Digital Radio Mondiale), and DRM+(Digital Radio Mondiale Plus) systems. The proposed MDI analyzer can reduce the overload of MDI packets by using memory sharing techniques into a common module block. In consequence, it verifies the received MDI packets by composition information of IP(Internet Protocol) and FAC(Fast Access Channel)/SDC(Service Description Channel) in DRM/DRM+ systems for the next generation digital radio broadcasting systems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.94-103
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• 2016

For elevated railway station on which track is connected with superstructure of station, structural vibration level and structure-borne-noise level has exceeded the reference level due to structural characteristics which transmits vibration directly. Therefore, existing elevated railway station is in need of economical and effective vibration reduction method which enable train service without interruption. In this study, structural vibration non-transmissible system which is applied to vibroisolating material for column member is developed to reduce vibration. That system is cut covering material of the column section using water-jet method and is installed with vibroisolating material on cut section. To verify vibration reduction effect and structural performance for structural vibration non-transmissible system, impact hammer test and cyclic lateral load test are performed for 1/4 scale test specimens. It is observed that natural period which means vibration response characteristics is shifted, and damping ratio is increased about 15~30% which means that system is effective to reduce structural vibration through vibration test. Also load-displacement relation and stiffness change rate of the columns are examined, and it is shown that ductility and energy dissipation capacity is increased. From test results, it is found that vibration non-transmissible system which is applied to column member enable to maintains structural function.