바이스태틱 레이더의 시스템 불안정 요소들에 대한 분석

양진모,이민준,윤재룡,김환우,Yang, Jin-Mo,Lee, Min-Joon,Yun, Jae-Ryong,Kim, Whan-Woo 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.1

In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a method to efficiently scan a restricted search area within the limited transmitter power and time in a bistatic radar and to track a series of transmitted pulses using the receiver beam which has ideally matched to the pulse propagation rate. In this paper, we have discussed the interrelationship between the pulse chasing and time and frequency/phase synchronization and described the effects of the identified system instability factors on two kinds of MTI filter configuration, single delay-line and double delay-line, in the bistatic radar. And also, we have confirmed that the overall system improvement is restricted by a lower improvement factor among identified them, and discussed the allowable tolerance of the time and frequency/phase synchronization in the bistatic system.

슬관절전치환술 후 연속수동운동(CPM)과 연속능동운동(CAM) 적용이 관절 고유수용감각에 미치는 영향

양진모,김선엽,Yang, Jin-Mo,Kim, Suhn-Yeop 대한물리치료과학회 2010 대한물리치료과학회지 Vol.17 No.1

Purpose: The purpose of this study was to compare the effects of continuous passive motion(CPM) and continuous active motion(CAM) on proprioception of the knee after total knee replacement(TKR). Methods: Twenty patients with TKR were randomly allocated into two groups, the CPM group(n=10) and the CAM group(n=10). All subjects were evaluated for levels of pain, passive range of motion and angle reproduction of the knee. An angle reproduction test was used to assess the proprioceptive deficit. Two types of angle reproduction test were used: a passive angle reproduction(PAR) test and an active angle reproduction(AAR) test. The relevant examinations were performed before and after intervention(on the 5th day and the 10th day). The statistical significance were calculated using a t-test and a one-way repeated ANOVA. Results: A pre-intervention significant difference was not found between the two groups. Significantly better results were before and after the intervention at 10 days, for the PAR(flexion direction) test; however, only in the CAM group. There were no significant difference, either before or after the intervention, for the AAR test(flexion and extension direction) in both group. Both groups experienced similar levels of pain and passive range of knee motion before and after the intervention. Conclusion: This study revealed that CAM was a better effect to restore position sense of the knee joint after TKR.

레이더 파형 연구 - 다위상 시퀀스

양진모,김환우,Yang, Jin-Mo,Kim, Whan-Woo 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.4

This paper describes and analyzes a various generation methods of the mutually orthogonal polyphase sequences with low cross-correlation peak sidelobe and low autocorrelation peak sidelobe levels. The mutual orthogonality is the key requirement of multi-static or MIMO(Multi-Input Multi-Output) radar systems which provides the good target detection and tracking performance. The polyphase sequences, which are generated by SA(Simulated Annealing) and GA(Genetic Algorithm), have been analyzed with ACF(Autocorrelation Function) PSL(Peak Sidelobe Level) and CCF(Crosscorrelation Function) level at the matched filter output. Also, the ambiguity function has been introduced and simulated for comparing Doppler properties of each sequence. We have suggested the phase selection rule for applying multi-static or MIMO systems.

레이더 시스템 성능평가용 가상 레이더 표적신호 발생장치

양진모,이민준,김환우,Yang, Jin-Mo,Lee, Min-Joon,Kim, Whan-Woo 한국군사과학기술학회 2008 한국군사과학기술학회지 Vol.11 No.3

In this paper, we have described a Simulated Radar Target Generation Equipment(SRTGE) for evaluating the performance of a developed radar system. In order to change a simulated target range(or time delay), the variable optical delay line structure is used in SRTGE, In addition, SRTGE is required to generate a target return signal which is composed of variable amplitude and Doppler velocity. The interference such as noise jamming and clutter is also produced from SRTGE for evaluating ECCM(Electronic-Counter-Counter Measure) capability of radar.

능동위상배열레이다용 레이다모듈 연구

양진모(Jin-Mo Yang),최준호(Jun-Ho Choi),권민상(Min-Sang Kwon),김태완(Tae-Wan Kim),한일탁(Il-Tak Han),임재혁(Jae-Hyuk Im),심국보(Kuk-Bo Sim),박영규(Young-Kyu Park),이희민(Hui-Min Yi),권호상(Ho-Sang Kwon),오선진(Seon-Jin Oh) 한국전자파학회 2024 한국전자파학회논문지 Vol.35 No.1

본 논문에서는 X-대역 능동위상배열 레이다에 적용되는 레이다모듈을 제안한다. 하드웨어적 확장성과 소프트웨어적 융통성을 갖는 레이다모듈은 레이다 요구성능에 따라 자유자재로 구성이 가능한 기본 블록이다. 레이다모듈은 DAC(digital-to-analog converter)를 이용한 레이다 파형생성, 주파수 상하향변환/증폭 및 ADC(analog-to-digital converter)/DDC(digital down converter)를 통한 I/Q생성과 1차 디지털 빔형성 및 전단 신호처리 기능들을 가진다. 또한, 레이다 모듈은 동일한 전기적 성능과 기능등을 갖기 때문에 개발 기간 단축, 예산 절감 및 공용화에 따른 이점을 가진다. 본 연구에서는 X-대역 능동위상배열 레이다에 적용할 수 있는 레이다 모듈의 개발결과와 시험결과들을 제시하였고 3×3 성능 검증배열안테나의 근접전계 시험결과를 통해 제안한 연구의 하드웨어적 확장성 및 소프트웨어적 융통성을 검증하였다. In this paper, we propose a radar module that can be applied to an X-band active phased-array radar. The radar module, with hardware scalability and software flexibility, is a basic block that can be freely configured according to system requirements. It generates radar waveforms using a digital-to-analog converter, frequency up-down conversion/amplification, baseband I/Q generation through an analog-to-digital converter or digital down converter, primary digital beamforming, and pre-signal processing functions. Because it has the same electrical performance and function, it has advantages such as reducing the development period, reducing the development budget, and improving maintenance and serviceability. This paper presents the radar module design and fabrication/test results applicable to X-band active phased-array radars. The hardware scalability and software flexibility of the proposed design were verified through a near-field test of a 3×3 array antenna.

표적 도플러 속도와 클러터 스펙트럼 특성에 따른 레이더 신호 처리기의 탐지 성능 분석

양진모(Jin-Mo Yang),신상진(Sang-Jin Shin),이민준(Min-Joon Lee),김환우(Whan-Woo Kim) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.1

MTI 필터는 대부분의 레이더 신호 처리에서 클러터로부터 표적을 분리하는데 이용된다. CFAR 검파 전 클러터를 제거됨으로써 탐지 성능이 개선될 수 있다. 레이더 시스템을 설계할 때, 일반적으로 설계자는 평균 SNR과 CNR을 고려하고 MTI 필터의 주파수 응답에 의한 영향은 포함되지 않는다. 실제의 경우, 클러터를 포함한 신호들이 필터를 통과할 때, SNR은 표적 속도에 따라 크게 변화하고, CNR 역시 클러터 중심 속도와 스펙트럼 퍼짐에 따라 변화하게 된다. 본 논문에서는 MTI 필터의 주파수 응답과 표적의 속도와 클러터의 스펙트럼 특성 간의 관계를 유도하였다. 필터 출력의 SNR과 CNR의 변화에 의한 CFAR 탐지 성능을 시뮬레이션을 통해 분석하였고, 성능에 미치는 영향을 확인하였다. MTI filter is used to separate target signal from clutter in many radar signal processing. By suppressing clutter before CFAR detection, the detection performance can be improved. As a radar system designed, a design engineer generally takes averaged SNR and CNR into account and does not include the effect of MTI filter's frequency response. In practice, when the signals including clutter are pass through the filter, SNR is widely varying according to target velocity and CNR is also varying according to clutter center frequency and spectrum spreading. In this paper, we have derived the relationship between the MTI filter's frequency response and a target's velocity and a clutter's spectrum characteristics. With the variation of SNR and CNR at the filter output, the detection performance of CFAR has been analyzed by the simulation and has made certain of their influences on the performance.

펄스 체이싱을 이용한 바이스태틱 레이더에서 수신 빔 조향 오차와 MTI(Moving Target Indication) 성능에 대한 연구

양진모(Jin-Mo Yang),이민준(Min-Joon Lee),김환우(Whan-Woo Kim) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.12

펄스 체이싱을 이용한 바이스태틱 레이더는 탐지 영역을 효과적으로 스캔하기 위해 수신 빔을 이용하여 송신 펄스를 추적함으로써 표적을 탐지한다. 수신 빔을 이용한 펄스 추적시 펄스-펄스간 빔 포인팅 오차에 의해 수신 펄스의 타이밍 오차와 신호 세기의 변화가 발생할 수 있다. 본 논문에서는 수신 빔 포인팅 오차에 의해 발생된 에러가 MTI 필터의 성능을 제한할 수 있음을 제안하였고, 바이스태틱 구조만의 고유한 특성인 기하학적 요소와 MTI 성능의 관계식을 유도하였다. 시뮬레이션을 통해 수신 빔 조향 오차에 의한 개선 성능 제한을 고찰하였고, 수신 빔의 조향 오차를 0.5도 이하로 유지함으로써 성능 개선에 기여할 수 있음을 확인하였다. A bistatic radar using the pulse chasing can detect a target to track successive transmitted pulses using a receive beam for effectively scanning the cosite search area. When tracking a transmitted pulse with the receive beam, some beam pointing errors within pulse-to-pulse can cause the timing error in received pulse and the variation of the signal strength. In this paper, we have proposed that some errors due to the receive beam pointing error could limit the MTI filter's performance and derived that the relationship between the MTI performance and the geometric factors which are the inherent properties in bistatic configuration. Through the simulation, we have considered the limitations of the improvement performance restricted by the receiving beam pointing error and confirmed the contribution to the performance improvement in maintaining the receiving beam pointing error of under 0.5 degrees.

흉추 관절가동술이 만성요통환자의 통증, 고유수용감각 및 균형수준에 미치는 효과

양진모(Jin mo Yang),김선엽(Suhn yeop Kim) 한국전문물리치료학회 2015 한국전문물리치료학회지 Vol.22 No.3

The purpose of this study was to investigate the effect of lumbar stabilization training and additional thoracic mobilization on pain, proprioception and static balance in patients with chronic low back pain. The subjects of this study were 48 chronic low back pain patients who were randomly allocated to an experimental group 1 (n1=16, lumbar stabilization and thoracic mobilization, thoracic hypomobility), experimental group 2 (n2=16, lumbar stabilization and thoracic mobilization, thoracic normal mobility), and a control group (n3=16, lumbar stabilization, thoracic hypomobility) after a thoracic mobility test. Both experimental groups underwent lumbar stabilization training and additional thoracic mobilization. The control group underwent only lumbar stabilization training. The intervention was performed 3 times per week, 30 minutes each time, for a total of 6 weeks. Thoraco-lumbar joint reposition error was measured using an electrogoniometer and static balance ability was measured using the Tetrax posture analysis system. Subjects' pain level was measured using a 100 ㎜ visual analogue scale. Statistical analyses were performed using a one-way analysis of variance and a paired t-test. Post-hoc testing was carried out with a Bonferroni test. The pain level was significantly lower in both experimental groups compared to the control group. Both experimental groups showed significant reductions in joint reposition error angle (flexion, extension, and side bending) compared to the control group. The static balance level was significantly lower in both experimental groups than in the control group. In summary, lumbar stabilization exercises and additional thoracic mobilization significantly improved the pain level, proprioception, and static balance in patients with chronic low back pain.

C-V2X Mode4 에서 전송 파워 컨트롤이 PRR 에 미치는 영향에 관한 연구

양진모(Jin Mo Yang),강병준(Byungjun Kang),박세웅(Saewoong Bahk) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.1

모바일 음성 언어 처리에서의 연산 오프로딩의 기작 및 효율성 분석

양진모(Jin Mo Yang ),박세웅(Saewoong Bahk) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.6