• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.252-259
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• 1994

The method of calculating overlap dispersion caused by group velocity mismatch between uv and visible pulses in ultrafast pump-probe experiments is presented to discuss limitations of the time resolution and signal intensity. The calculations show arrangements using a single focusing lens shall result in undesirable time resolution and low signal intensity. Achromatic doublets result in unrealistic solutions. However, dramatic improvement in the time resolution and signal intensity is expected in the optical arrangements using separate lens for each pulse and in the arrangements using a cutoff secondary lens with a main lens. lens.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1843-1845
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• 2000

GIS(Gas insulated switchgear)내부에서 발생한 부분방전 신호를 검출 할 수 있는 UHF(Ultra-high frequency) 부분방전 검출 센서를 345 kV GIS의 AC 내전압 시험에 적용하였다. 부분방전 센서를 적용한 상태에서 각 상별로, bus별로 나누어 계통 최고전압의 1.0 p.u, 1.5 p.u, 1.73 p.u 전압을 단계적으로 인가하였으며 간헐적으로 부분방전 신호가 검출됨을 확인하였다. 간헐적인 부분방전 신호는 GIS 내부에 있던 이물질에서 약한 방전이 시작되고 인가전압을 높임에 따라 방전의 강도가 증가하다 소멸되었다. 방전을 일으킨 이물질이 모두 증발되었거나 위치 변화에 의해 방전이 소멸된 것으로 판단된다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.315-320
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• 2003

최근 산업용 기계·기구 및 설비는 과거 아날로그 제어방식에서 전자회로를 이용한 디지털 제어방식으로 전환됨에 따라 제어장치가 소형화퇴고, 기능의 다양화 및 초정밀 제어가 가능해 졌다. 그러나 각종 전자파 잡음 발생원이 많아지고 기계장치의 제어에 약한 신호가 이용되고 있기 때문에 전자파 장해로 인한 산업재해와 생산차질, 불량품생산 등 여러 부작용의 원인이 되고 있다. 이에 선진국의 경우 전자파 적합성(EMC)에 대한 규제대상과 안전기준을 점점 강화하는 추세에 있으며, 우리나라의 경우도 가전제품, 통신장비 등은 전파법, 전기용품안전관리법 등으로 오래 전부터 전자파 안전대책을 의무 규정화하여 규제하교 있다.(중략)

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.209-209
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• 2004

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.231-232
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• 2013

몽골은 중국과 러시아에 의해 바다를 접할 수 없는 내륙국가로서, 지정학적의 한계를 가지고 있어 해운산업의 역할이 매우 약한 나라이다. 하지만 해상운송의 중요성과 내륙 복합운송의 증대로 인하여 몽골에서도 해운의 중요성이 부각되고 있다. 이러한 상황에 중요한 것이 해운 인적 자원 양성이라고 판단된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.375-382
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• 2018

To eliminate strong jamming signals, a radar acquires a relatively weak target signal by using a side-lobe canceller (SLC) algorithm. This paper presents a novel adaptive SLC algorithm that is applicable to a fully digital active array radar. First, a covariance matrix is obtained from the SLC beam. Then, an adaptive SLC coefficient is extracted after calculating the correlation matrix between the main beam signal and the SLC beam signal. Finally, the target signal is estimated and the jamming signal is removed through the operation with the main beam signal. The application results from simulated radar signals demonstrated that the proposed algorithm is effective in an SLC system. Moreover, we analyzed various considerations and improved systematic usability.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.823-834
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• 2013

In this paper, we propose a detection method for Digital Radio Mondiale (DRM) Plus suitable for hybrid mode broadcasting which services both DRM Plus and analog FM within the same frequency band. The guard-interval correlation method of Orthogonal Frequency Division Multiplexing (OFDM) is good for DRM Plus signal detection, but the possibility for false alarm increases when FM signal is received. The proposed method includes a reference block in the guard-interval correlation which increases the identification rate of weak DRM Plus signals and decreases the possibility of false alarm when analog FM is received. The performance of the proposed method is verified through simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1175-1183
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• 2001

In this paper, we use hyper chaos circuit which is made through the phase differences which is generated during the process of weak-coupling of CNN between two and more chaos attractors. Notwithstanding the complexity of the hyper chaos, we could do the synchronization and according to it, Secure communication through this method coo]d be accomplished. On this research, we configurated 2-double scroll and 3-double scroll circuit ,not using Chua circuit, but SC-CNN(State-Controlled CNN) which is more flexible to configure the system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.3
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• pp.219-231
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• 1991

In this paper, various results on Iocally optimum detection of signals are reviewed concisely, which are easlily apphcable to weak signal detection problems. In addition, locally optmum rank detection schemes for weak signals are reviewed, which are nonparametric counterparts of the locally optimum detecturs. Examples of practical applications, problems in implementation dnd performance characteristecs of the locally optimum detectors are also discussed, Finally, a fuzzy extension of the generalized Neyman Pearson lemma is briefly discussd.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1824-1830
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• 1998

In this paper, we investigate a noise reduction scheme, based on the inherent characteristic of an orthogonal sequence. The modulated orthogonal code generates sequences of length $N^{2}$ from N information symbols. Using the amplitudes of the received symbols, we first estimate the location of the smallest amplitude noise. Then the noise is reduced by the suggested system. The performance of the scheme is confirmed by computer simulation results.