주파수 공유기법을 적용한 RF 송수신기에 대한 연구

김기중,김종성,배문관,Kim, Ki-Jung,Kim, Jong-Sung,Bae, Moon-Kwan 한국전자통신학회 2015 한국전자통신학회 논문지 Vol.10 No.12

In this paper Communication data link equipment on a high speed-hopping method to use the frequency resources efficiently for the frequency environment is introduced such as sensing techniques, using the same frequency band by using the received two-channel technique and the receive filter bank unit applied to be shared with other equipment such as radar and so on. The real-time measurement and analysis were operated for measurement the frequency environment of the operating band in advance. and primarily equipment to develop is analyzed how the interference effect to the radar minimize the operation of radar equipment. In reverse, to use the same frequency band the methods such as frequency sharing techniques are presented in this paper. Finally, by design of the main items of the RF transceiver NF, transmission output, and a simulation of the IMD, such as whether the key is verified prior to meet specifications.

GaAs MMIC를 이용한 X대역용 25W급 전력증폭모듈의 설계 및 구현에 대한 연구

김기중,김봉수,Kim, Ki-Jung,Kim, Bong-Soo 한국전자통신학회 2014 한국전자통신학회 논문지 Vol.9 No.11

To be used in a transmitter of a satellite transponder of this paper, X band 25W power amplifier module, a part constituting of high-power amplifier is transmitted to the equipment for transmitting to geostationary communications satellites(36,000Km distance). PAM consisted a total of four power amplifier module has a high output characteristic of the high-output amplifier is used in the ground station. Used in conjunction with the structured type power amplifier module is composed of Serial Combining Structure. This PAM(Power Amplifier Module) configured by combining the circuit with the power amplifier, 10 MMIC chips and the Al2O3 thin film substrate using a Hybrid Technique of power amplifier module, was implemented at X band PAM(Power Amplifier Module) of 25W grade.

디지털위성중계기 시스템 성능 분석 및 구현

김기중,서학금,Kim, Ki-Jung,Seo, Hak Geum 한국전자통신학회 2014 한국전자통신학회 논문지 Vol.9 No.4

This study introduces about the analysis, verification and implementation of Digital Communication Satellite transponder. Through the pre-performance analysis of each component by the circuit level simulation, each component's performance was checked whether satisfying the specifications. When each of the components was connected in order, System's performances were evaluated through system harmonic balanced simulation whether satisfying the specifications. Through pre-analysis of the system performance, specification of each component was defined. On the basis of that specification, Components which comprise the Digital Communication Satellite repeater were manufactured, and finally, the overall system performance check was made by integrating the components of Digital Communication Satellite transponder.

다중포인트 통신 프로토콜을 지원하는 디지털 화재 방지 모니터링 시스템 구현에 관한 연구

김기중,Kim, Ki-Jung 한국전자통신학회 2012 한국전자통신학회 논문지 Vol.7 No.6

In this paper, we investigated an implementation of anti-fire monitoring system based on the RS-485 communication to support local area coverage within a range of 1 Km range. We developed a Multi Point Communication Protocol supporting input/output information processing and control up to 8128 terminal check points, which provides an interface between the anti-fire monitoring system receiver and multiplex transponders. Additionally, a multiplex transponders controller has been designed for the implemented system to comply with the government regulation on fire protection, especially to monitor, report and control 1016 terminal check points within the time limit.

정원줄기세포의 이종간 이식을 위한 효율적인 수여(Recipient) 생쥐 생산 기법 개발

김기중 ( Ki Jung Kim ),임한 ( Han Lim ),왕종현 ( Jong Hyun Wang ),김병각 ( Byung Gak Kim ),이용안 ( Yong An Lee ),김방진 ( Bang Jin Kim ),김용희 ( Yong Hee Kim ),홍영호 ( Yeong Ho Hong ),김근배 ( Geun Bae Kim ),류범용 ( Buom Yong 한국조직공학·재생의학회 2013 조직공학과 재생의학 Vol.10 No.1s

Spermatogonial xenotransplantation assay provides access to the several species germline and has been used in experimental animal models to study stem cell biology and germline development. To make the xenotransplantation technology more extensively accessible, it is require development of recipient preparation protocols. Therefore, we propose an optimal method for preparation of athymic nude recipient with busulfan treatment. To investigate the optimal concentration of busulfan treatment, athymic nude mice (6~8 weeks old) were intraperitoneally injected with different concentrations of busulfan (0, 15, 25, 35 and 45 mg/kg). 6~8 weeks after busulfan treatment, testicular weight was significantly lower in 45 mg/kg treated group than the other groups. And the percentage of spermatogenic tubule was significantly reduced in 45 mg/kg of busulfan treated recipient testis. Also we compared the gene expression level of sertoli-cell-derived growth factor, glial-cell-line-derived neurotrophic factor (GDNF) as a potential measure of niche function. Relative to the other experimental groups, 45 mg/kg busulfan treated recipient testis showed higher GDNF expression. Next, to find out the appropriate time to transplantation after treated with busulfan (45 mg/kg), the rat testicular donor cells were transplanted into recipient testis at 2, 4, 6 and 8 weeks after treated with busulfan. Analysis of recipient mice revealed that transplantation of donor cells on 6 weeks after busulfan treatment was the most effective time to support high level of donor stem cell engraftment. In this study, we provide an optimum experimental condition for preparation of recipient mouse model system for xenotransplantation. Also, our data could contribute to recipient preparation in other species.

SRM형 BLDC 모터의 소음 제어 문제 및 저소음 초기 구동 구현에 관한 연구

김기중(Ki-Jung Kim),임형규(Hyung-Kyu Im),이창기(Chang-Ki Lee) 한국엔터테인먼트산업학회 2014 한국엔터테인먼트산업학회논문지 Vol.8 No.3

Blushes are known to generate unwanted nano particles of dust and harm elements in various electro-mechanical home appliances. Subsequently, the blushless type is proposed as an eco-friendly alternative to replace the brushes, and the expensive magnetized rotor of the Blush-less DC (BLDC) is to be replaced in SRM, which requires complex control not to overflow the switching current the system within a budget. A know weak point of the SRM-BLDC is that there is a strong starting noise due to the initial slipping of the rotator and subsequent mechanical vibration. This paper introduces an approach to implement an cost-effective starting noise controller for high-speed rotation control, employing Switched Reluctance Motor (SRM) BLDC motor.

공동구용 수직구 접속부 보강/차수 장치 시제품 개발

김기중 ( Kim Ki-jung ),강지훈 ( Kang Ji-hoon ) 한국구조물진단유지관리공학회 2019 한국구조물진단유지관리공학회 학술발표회 논문집 Vol.23 No.2

공동구용 수직구 접속부는 부등침하 발생, 지하수위 저감, 지진 등 동하중에 의한 상대변위 발생 등의 문제점이 야기되고 있다. 현재 국내에서는 수직구 접속부 시공 시 지반안정화를 위한 각종 공법을 적용하고 있으나, 접속부에 대해 직접적인 보강/차수 기술 적용은 전무한 실정이다. 따라서 본 연구에서는 공동구용 수직구 접속부에서 야기되고 있는 문제점을 상쇄할 수 있는 공동구용 수직구 접속부 보강/차수 장치 시제품을 개발하였다.

손금과 정맥혈관 패턴매칭을 이용한 비접촉 출입 보안시스템 설계

김기중(Ki-Jung Kim) 한국전자통신학회 2024 한국전자통신학회 논문지 Vol.19 No.1

본 논문에서는 라즈베리파이 기반으로 손바닥 정맥혈관 이미지를 획득하기 위하여 950nm파장을 가지는 근적외선 LED 광원 장치와 손금을 획득하기 위한 백색 LED 광원 장치를 가지는 시스템을 개발하였다. 또한 획득한 정맥 및 손금 이미지에 대하여 영상 전처리 과정(흑백화, 평활화, 이진화, 블러링, 세선화 등)을 통하여 정맥과 손금이 혼합된 위조 방지 및 보안이 강화된 고유 패턴이 추출 가능한 영상처리 기술을 구현하여 보안성이 강화된 시스템에서 활용할 수 있는 원천 기술을 확보하였다. In this paper, we developed a system with a near-infrared LED light source with a wavelength of 950nm to acquire palm vein images and a white LED light source to acquire palm creases based on Raspberry Pi. In addition, we implemented a unique pattern-extractable image processing technology that can prevent counterfeiting and enhance security of mixed creases and palm prints through image pre-processing (Gray scaling, Histogram Equalization, Blurring, Thresholding, Thinning) for the acquired vein and palm images, and secured a source technology that can be used in a security-enhanced system.

쉴드터널-수직구 접속부 보강/차수 장치 개발

김기중 ( Kim Ki Jung ),강지훈 ( Kang Ji Hoon ) 한국구조물진단유지관리공학회 2017 한국구조물진단유지관리공학회 학술발표회 논문집 Vol.21 No.2

Shield tunnel-shaft joint has caused problems in use which has different soil condition and boundary condition according to structure type. For solving this problems we developed joint reinforcing and inflow water cut-off system which can ensure stability of shield tunnel-shaft and reduce costs of maintenance.

수중 양식어류 계수 추정을 위한 Echo-Sounder 개발에 관한 연구

김기중(Ki-Jung Kim),선휘준(Hwi-Joon Seon),이영석(Yeong-Seok Lee) 산업기술교육훈련학회 2020 산업기술연구논문지 (JITR) Vol.25 No.4

An acoustic echo-sounder is an effective piece of equipment used to detect underwater targets by emitting ultrasonic waves and receiving reflections from the targets. In this study, we present a new compact echo-sounder and implement a new signal processing algorithm to estimate fish populations. Experimental results demonstrate that our device has comparable scattering strength and signal patterns to those of a popular acoustic echo-sounder (Simrad, EK-15). Because our method accurately estimates fish abundance, the method is reliable for making fish-management decisions.