• 한국화재소방학회논문지
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• 제24권2호
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• pp.178-184
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• 2010

본 연구에서는 화재로 인하여 발생되는 연기 또는 열을 무선화재감지기에서 감지하여, 유선이 아닌 무선장치를 이용하여 수신장치까지 전송하고, 이 감지신호를 유선을 통하여 메인서버로 전송하는 유무선통합감지시스템을 제안한다. 또한 무선 열/연감지기, 무선모듈, 펌웨어, 유무선통합수신반 등을 개발하였으며, 유무선장치의 성능과 실용성에 관한 검증을 위하여 송신탑, 주상복합건물, 지하철역사 등에서 실제 현장적용 실험을 수행하였다. 실험결과, 제안한 시스템은 모든 실험대상물에서 정상적으로 동작하였으며 향후 현장적용이 가능함을 확인할 수 있었다.

• 전기학회논문지
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• 제64권11호
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• pp.1651-1657
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• 2015

In MHz operating wireless power transfer systems, skin- and proximity-effect losses in the transmitter and the receiver coils dominate the coil-to-coil efficiency of the system. A Litz-wire was regarded as a common solution for minimizing such Ohmic losses in high frequencies. In this paper, equivalent series resistances of 12 different cables including Litz-wire and copper tubing have been calculated and measured for a 6.78 MHz, 100W, 30 cm wireless power transfer system. It has been shown that the copper tubing has lower resistances compared to the Litz-wire in that frequency and a wireless power transfer system with the copper tubing was able to achieve much higher efficiency than a system using the Litz-wire. Calculations of the resistances and efficiencies were accomplished with analytical equations and those calculations were evaluated by experimental results.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.227-230
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• 2000

Chuas circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chuas circuits are proposed and synchronizations of a equivalent wire and wireless power line are investigated. Since the synchronization of the equivalent wire and wireless system is impossible by coupled synchronization, theory having both the drive-response and the coupled synchronization is proposed. As a result, the chaos synchronization has delay characteristics in the equivalent wire and wireless transmission system caused by the line parameters L and C.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.599-603
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• 2006

한국정보보호진흥원은 2002년부터 정보보호관리체계 인증제도를 시행해, IDC 업체들에 대한 기술적 물리적 보호조치를 포함한 종합적 관리체계가 해당 서비스에 적합한지를 심사하여 인증을 해주고 있다. 하지만 이 인증제도는 유선과 무선으로 각각 분리된 IDC 환경에 대한 독립된 기준으로, 유 무선 통합 환경에서의 평가기준은 아직까지 마련되어 있지 못한 상태이다. 본 논문에서는 집적정보통신시설보호지침 및 무선랜 보안 운영 권고지침, 국내 외 정보보호 관련 지침 및 권고사항, IDC 환경을 분석한 자료를 바탕으로 유선과 무선이 통합된 IDC 네트워크 모델을 제시하고, IDC 평가기준을 제안하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.231-234
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• 2000

In this paper, we formed a transmitter and receiver by using three identical Chuas circuits and then formed wire and wireless transmission line from the channel which was between those three circuits. We proposed a secure communication method in which the desired information signal was synthesized with the chaos signal created in a Chuas circuit and sent to the transmitter through channel. Then the signal was demodulated receiver of Chuas circuit. The method we used to accomplish the secure communication was synthesizing the desired information with the chaos circuit by parallel connection in a wireless transmission line. After transmitting the synthesized signal to the wire and wireless transmission line, we confirmed the actuality of the secure communication by separating the information signal and the chaos signal in the receiver.

• 소성∙가공
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• 제32권6호
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• pp.303-310
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• 2023

Electrohydraulic forming(EHF), one of the high-speed forming method, can supplement the weak point of previous forming process such as deep-drawing and electromagnetic forming. Indeed, EHF is time-consuming process during installing wire before experiment that hard to apply to industry. In this research, applying wireless electrode, the formability of SUS430 sheet was compared through EHF experiments using wire-installed electrode and the other, wireless. Although the power was a little lacking, the advantages of the experiment using wireless electrode could be confirmed with checking the optimal location of electrodes where the plasma is generated and comparing free-bulging height depending on former and later condition of electrodes with performing several single and multistage experiments for same voltage, 6 kV.

• 전기학회논문지
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• 제63권2호
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• pp.306-312
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• 2014

The ZigBee communication method, which is the most frequently applied to the LED lighting control system, has drawbacks of low-speed and low-capacity, and the communication failure possibility due to environmental influences is on the rise. Therefore, it is important to secure the communication reliability by applying an integrated interface with a wire-wireless dual-network. This paper developed a communication module, which has a platform converging and combining the ZigBee of USN environments with the PLC of power line communication environments, to implement a dualized communication interface system supporting the wire-wireless integrated protocol, and implemented a wire-wireless networking device and a control system software technology. As a result, it was automatically switched into the PLC communication within 4.4 seconds on average when there was an access failure in the ZigBee communication network, so a reliable communication network was built.

• 한국음향학회지
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• 제22권3호
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• pp.182-187
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• 2003

본 논문에서는 방사 기저함수 (RBF: Radial Basis Function) 신경망을 이용하여 특징 파라미터를 사상시켜 화자인식의 성능을 개선하기 위한 알고리즘을 제안하였다. 동일한 화자의 유무선 전화의 백터 영역이 서로 다르므로 제안한 화자확인시스템은 유무선 학습모델을 생성하기 위해서 먼저 음성인식을 통해 유무선 채널을 판별하고, 학습하지 않은 채널의 모델은 방사 기저함수 신경망을 이용하여 학습된 모델의 특징 벡터 (LPC-켑스트럼)를 사상하는 방법이다. 모의 실험 결과 기존의 켑스트럼 평균 차감법을 사용할 때보다 제안한 알고리즘을 적용했을 때의 인식율이 약 0.6%∼10.5%의 성능 향상을 보여주었다.

• 한국컴퓨터정보학회논문지
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• 제7권2호
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• pp.46-52
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• 2002

모바일의 확산, 이동성, 그리고 휴대성은 유선 인터넷의 추세를 점차 무선 인터넷으로 전이시키고 있다. 이에, 기업의 일선 업무 담당자들과 일반인들은 모두 모바일 폰. PDA를 활용하여 지역에 관계없이 이동을 하면서 기업정보와 국가정보에 접근할 수 있게 되었다. 이에 따라 기업정보 도용과 개인정보를 악용하는 경우가 자주 등장함에 따라 정보보호가 사회전반에 큰 이슈화되고 있다. 본 논문에서는 정보보호를 위한 침입탐지 시스템을 설계하고자, 유선 인터넷의 침입 유형과 침입탐지 기법을 살펴보았다. 본 논문은 모바일 무선 인터넷에 의한 시스템 접근 시에 침입을 탐지, 분리하며, 정상으로 가장하여 시스템 내부에 침입한 경우를 탐지하고자 circuit patrol을 시스템 내부에 위치시켜 정상적인 것처럼 시스템에 들어온 침입에 대한 공격을 탐지하는 모델을 제시하였다.

• Journal of Power Electronics
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• 제18권4호
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• pp.1268-1277
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• 2018

A relatively high operating frequency is required for efficient wireless power transfer (WPT). However, the alternating current (AC) resistance of coils increases sharply with operating frequency, which possibly degrades overall efficiency. Hence, the evaluation of coil AC resistance is critical in selecting operating frequency to achieve good efficiency. For a Litz wire coil, AC resistance is attributed to the magnetic field, which leads to the skin effect, the proximity effect, and the corresponding conductive resistance and inductive resistance in the coil. A numerical calculation method based on the Biot-Savart law is proposed to calculate magnetic field strength over strands in Litz wire planar spiral coils to evaluate their AC resistance. An optimized frequency can be found to achieve the maximum efficiency of a WPT system based on the predicted resistance. Sample coils are manufactured to verify the resistance analysis method. A prototype WPT system is set up to conduct the experiments. The experiments show that the proposed method can accurately predict the AC resistance of Litz wire planar spiral coils and the optimized operating frequency for maximum efficiency.