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단일 안테나를 사용하는 W-대역 호모다인 FMCW 레이더의 누설신호에 의한 IF 잡음에 관한 연구
박정동,김완주,Park Jung-Dong,Kim Wan-Joo 대한전자공학회 2005 電子工學會論文誌-TC (Telecommunications) Vol.42 No.7
본 논문은 단일 안테나를 사용한 호모다인 방식의 W-대역 주파수 변조 연속파형 (FMCW) 레이더 송수신장치의 송수신단간의 신호 결합에 의해서 발생하는 누설에 의한 IF 잡음의 특성을 분석하여 이를 효과적으로 제거할 수 있는 방안을 제시한다. 송수신장치에서 발생하는 누설은 LO 신호의 지연시간을 안테나 입력단의 부정합으로 인해서 발생하는 반사전력의 지연시간과 일치시켜 그 크기를 줄일 수 있다. 또한, 중간주퐈수(IF) 잡음은 주기적인 특이점을 가진 신호로써 VCO의 삼각파변조신호와 매우 유사한 스펙트럼 형태를 가짐을 확인하였다. 분석된 결과를 바탕으로 W-대역 호모다인 FMCW레이더 센서를 구현 하였으며, 표적감지 및 비트신호 검출 시험을 성공적으로 수행하였다. 본 분석 결과는 단일 안테나를 사용하는 호모다인 FMCW 레이더의 설계에 유용하게 적용될 것이다. In this paper, we describe a solution to improve the effects of the transmitter leakage signals on the frequency modulated continuous wave (FMCW) radar with a single antenna configuration. We analyze characteristics of the IF noise caused by insufficient isolation between transmitter and receiver. The magnitude of the intermediate frequency (IF) noise from a front-end can be reduced by matching the LO signal delay time with that of the largest leakage source. Because the IF noise has periodic singularities at nT$_{m}$/2, t=0,1,2$\cdots$, we find that spectrum of the IF noise due to the leakage signals is very similar to that of the VCO moduation signal except low frequency elements in the vicinity of DC. Based on the studies, we fabricated a W-band homodyne FMCW radar sensor and verified the proposed solution. The results are applicable to design of the homodyne FMCW radar with a single antenna configuration.
박정동,김경희 한국동북아경제학회 2005 동북아경제연구 Vol.17 No.2
China with high potential of economic growth is in a bitter competition against Korea in most of the industries. China has been reorganizing the steel & metal industry through capital intensification strategy (고도화 전략) and changed to a strong competitor in this industry. The purpose of this study is to analyze competition status in the steel & metal industry between Korea and China, especially comparing this industry's competing areas before and after China's joining of WTO. HS 4 unit code in the steel & metal industry was used to analyze. The result of the study shows little difference before and after China's joining of WTO in competing degree. Korea still takes competitive advantage in most of the steel & metal industry areas. This status is expected to sustain for the time being. However, China‘s government will reform economic policies more intensively to meet WTO's standard. China's corporations will also be equipped to increase efficiency and compete in free economic market (시장경제). China's major industries will be transformed to heavy industries from labor intensified industries by the government's efforts and this will threaten Korea's competitive advantage in the steel & metal industry .
박정동,이현배,국태용 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1
In this paper, we present a nonlinear adaptive controller for position tracking of induction motors. In constructing the adaptive controller, a backstepping approach is used under the condition of full state information, while a nonlinear observer is adopted for rotor flux estimation. The adaptive controller is shown to drive the state variables of system to the desired ones asymptotically and whose effectiveness is also shown via computer simulation.
지면 클러터 환경에서 금속표적감지를 위한 W-대역 FMCW 레이더의 설계 및 제작
박정동,Park Jung-Dong 한국군사과학기술학회 2004 한국군사과학기술학회지 Vol.7 No.3
In this paper, we describe the design, fabrication, and test results of a W-band FMCW radar for the metal target detection under the ground clutter environment. In order to detect metal targets on the ground, we used a single cassegrain antenna with the beamwidth of $1.45^{\circ}$ which forms pencil-beam footprint on the ground. A log envelope detector was applied to improve radar performance in the severe ground clutter known as Weibull and log normal clutter. The designed FMCW radar can acquire altitude information from the ground clutter with $\sigma_0=-23dB$ at the height of 160m. The fabricated W-band FMCW radar transmits 11 dBm power and the dynamic range of the receiver is from -106dBm to -30dBm. The performances of the fabricated sensors were tested out in the fields and detected a car target of 200m apart on the grass.
박정동,김경희 한국동북아경제학회 2004 동북아경제연구 Vol.16 No.2
This study wishes to examine competition relation of whole industry to analyze competition degree by industry between Korea and China, and one of several items in competition relation among them searches for competition degree through the analysis. First, in this study after choose textile industry parts among industry of several items and examine the result through analysis of details item wish to. Textile industry of the Korea is high quality & high price competition, and the China may no be shrinkage that the China is enormous in korea economic even if competitive power rises sharply shortly because is taking price competition that use labor power that is inexpensive yet. But, through the 10th 5 year plan period(2001~2005) for long-term, industry structural reform and height, development raising of service part, national economy and information ․ acceleration of society in industrial structure reorganization more spur. IBRD is forecasting that textile export amount of materials that made in the China around 2005 may dominate 47.1% of all the world export amount of materials. The China government also has plan to solidify textile industry restructuring for competitive power raising and world market share raising of textile goods to do to convert from Chinese 'Enormity fiber department' to 'Great fiber department' during the 10th 5 year plan period. Therefore, inescapable competitorship may form as well as deepen competition relation with the Korea in several industries if item in competition relation may increase more in textile industry, and Chinese walking is decided according to such plan.
E . coli cryptic miniplasmid p 15A 에서 유래하는 플라스미드 pACYC 184 의 ssi 시그날에 관한 연구
박정동,Sakai Hiroshi,Tohru Komano ( Jeong Dong Bahk,Hiroshi Sakai,Tohru Komano ) 생화학분자생물학회 1990 BMB Reports Vol.23 No.1
Single-strand DNA initiation (ssi) signals are DNA requirements for initiation of DNA synthesis on the single-strand DNA templates. For primary screening of ssi signal function, we used plaque morphology method. Plasmid pACYCl84 derived from E. coli minicryptic plasmid p15A had only one ssi signal which consists of 119-nt stretch. This segment played critical roles in ss DNA phage growth activity and performed primase-dependent replication instead of RNA polymerase-dependent one. Three kinds of energetically stable stem and loop structures were expected. Especially, the orientation and location of this 119-nt stretch, when compared with those of the origin of p15A, favor that this ssi signal might be taken part in the lagging strand replication of plasmid pACYCl84.