• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1084-1093
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• 2017

As the survivability of an aircraft in the battlefield becomes a critical issue, there is a growing need to improve the survivability of the aircraft. In this study, the survivability of an UCAV associated with plume IR signature was investigated. In order to analyze the survivability of the aircraft, the lock-on range and the lethal envelope, defined as the IR detection distance of the aircraft and the range of shooting down by the missile, respectively, were first introduced. Further, a method to calculate the lethal envelope for the scenario of surface-to-air missiles including the vertical plane was developed. The study confirmed that the red zone of an UCAV shows a substantial difference in the zone size as well as the characteristics in the upward and downward directions.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.8
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• pp.580-587
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• 2003

In this paper, we introduce a novel model to analyze the linearity of a TW-EAM (traveling-wave electroabsorption modulator). The device length, microwave loss (ML), and internal reflection (IR) due to impedance mismatch have effect on the linearity of a TW-EAM. The longer devices have characteristics of lower biases with minimum IMDS (intermodulation distortions). ML decreases the output power as well as the IMD value. Internal reflection has different nonlinear characteristics according to the wavelength of the input frequency and the device length. There is little change in SFDR (spurious-free dynamic range) due to ML or IR. As a result, for a 50 GHz band RF-optical communication system, a 0.8 mm-long TW-EAM with the lowest ML would have better properties by using n, which is caused by impedance, mismatch at the output port.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1672-1681
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• 2000

초광대역 시간 도약 이전 임펄스 무전 전송 시스템의 성능 평가 1672 최근 들어 실내 무선 LAN(local area network)이나 군용 무선 통신 시스템을 위한 새로운 대역 확산 전송방식으로서 초광대역 시간 도약 임펄스 무선 전송(ultra wideband time hopping impulse radio; 이하 IR) 기술이 큰 관심을 모으고 있다. 신호 전송을 위해 연속적인 정현파를 이용하는 기존의 무선 전송 시스템과는 달리 IR 시스템은 1 nese 이하의 매우 짧은 펄스폭의 펄스 위치 변조(pulse position modulation)된 가우시안 모노사이클 멀스 열을 이용하므로서 매우 작은 크기의 수 GHz에 이르는 초광대역 스펙트럼을 가지며 기존의 통신 시스템에 거의 간섭을 미치지 않으며 사용 가능하다. 본 논문에서는 동기식 이진 (synchronous binary) IR 시스템의 성능 분석 및 평가 결과를 제시하고자 한다.이를 위해 의사 잡음 부호 발생기와 decimator로 구성된 시간 도약 패턴을 사용 하여 다원 접속 간섭 이 배제되는 동기식 이진 IR 시스템의 비트 오율에 대한 closed form 결과를 유도하고, 유도된 이론적인 성능 결과를 부가성 백색 가우시안 잡음 채널에 대한 모의 실험을 통해 확인하였다. 또한 모의 실험을 통해 상관 복조기에서 발행한 렌덤 타이밍 지터에 대해 IR 시스템의 강인한 특성을 확인하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.174-174
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• 2017

농지의 구성물을 인식하는 기술은 농작업 기계를 로봇으로 전환하는데 필요한 기술 중 하나이다. 하지만 실외에서는 태양광과 날씨 변화에 따른 광 조건의 변화가 매우 커서 기존의 영상처리 방법으로 구성물을 인지하는데 한계가 있었다. 본 연구에서는 광 조건의 변화에 따른 영향을 줄이는 방안으로 IR 이미지를 이용한 농지 구성물의 인지를 수행하였다. 농지 구성물로는 토양, 식물, 멀칭비닐, 자갈을 선정하였다. 농지의 IR 이미지에서 농지 구성물을 구별하기 위한 픽셀값을 작게 적용하면 미세한 구분은 가능하지만 토양, 식물, 멀칭 비닐 등을 구성물 단위로 구별할 대는 후처리가 필요로 해지는 문제가 발생하였다. 본 연구에서는 IR 영상의 픽셀값을 평균 처리하여 농지 구성물의 인지를 수행 때의 효과를 확인 하였다. 평균 처리하는 픽셀값이 많을수록 처리속도가 빠르고, 작은 노이즈를 제어하는 효과가 있었지만, 픽셀값이 너무 커지면 구조물의 구별 정확도가 떨어졌다. 이 결과를 바탕으로 농지 구성물 인지를 위한 효율적인 IR 이미지 평균 처리 수준을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1371-1379
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• 2010

This paper presents an analysis of impulse dispersion for impulse radio ultra-wide band(IR-UWB) antenna. A set of antenna structure configurations are highlighted with verification based on the STFT(Short Time Fourier Transform) in 3.1~5.1 GHz: first, a taper-slotted antenna allowing the optimal impulse transmission, and second, 4 types of the omni-directional IR-UWB antenna using different feed structures(microstrip line, and CPW(Coplanar Waveguide)). The proposed STFT allows the analysis of the IR-UWB antenna's dispersion characteristic.

• Proceedings of the KWS Conference
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• 1999.10a
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• pp.117-121
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• 1999

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.185-190
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• 2020

The rapid aging is increasing as the shortage of medical facilities and the resulting of decline in the quality of public health. In order to ease the burden of rising medical expenses, advanced medical institutions are expanding their remote medical care to lower the cost of services. U-healthcare detects the changes in physical and chemical phenomena occurring in the human body and converts them into electrical signals that can be processed and feeds back to the results through analytical and visualization processes to select only the desired information from the measured signals. The service is provided through a process of providing an alarm to a user. However, traditional biometric methods of attaching sensors directly to the body can be annoying and rejected in daily life. Therefore, there is a need for a method of continuously measuring biometric information without causing inconvenience to daily life. In this paper, we propose an IR-UWB-based non-contact and non-responsive respiratory measurement system that can continuously monitor biological information without any inconveniences to daily life.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.71-78
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• 2004

An infrared remote control-type transcutaneous control device using a $\mu$-processor is design for the totally implantable middle ear system. An infrared light transmission model for the tissue of skin was introduced and then a radiant intensity and the required current of the infrared light emitting diode(IR LED) driving circuit at transmission part were calculated for the external control device. And the transmission part generates IR signal by the system's own data protocol which prevents interferences from other infrared remote controls of the household appliances. The control part of the implanted device was designed to analyze functions of the received infrared(IR) signal that indicate the power ON/OFF and volume UP/DOWN. After the system is implemented, a data transmission experiments using 4 mm thickness of porcine skin were carried out. From the experiment, it was verified that the infrared control signal was transmitted to receiving module of the implemented system without any error.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.1
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• pp.63-72
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• 2020

As the design complexity and performances are increased in satellite electronic board, noise related problems are also increased. To minimize the noise issues, various design improvements are performed by power integrity and signal integrity analysis in this research. Static power and dynamic power design are reviewed and improved by DC IR drop and power impedance analysis. Signal integrity design is reviewed and improved by time domain signal wave analysis and PCB(Printed Circuit Board) design modifications. And also power planes resonance modes are checked and mitigation measures are verified by simulation. Finally, it is checked that radiated noise is reduced after design improvements by EMC(Electro Magnetic Compatibility) RE(Radiated Emission) measurement results.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.31-37
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• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.