표적의 자세 변화를 고려한 계측 레이더의 비콘 추적 성능 분석

류충호,예성혁,황규환,서일환,Ryu, Chung-Ho,Ye, Sung-Hyuck,Hwang, Gyu-Hwan,Seo, Il-Hwan 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.4

Instrumentation radar in a test range has an important role to measure target's TSPI(time, space, position, information). It is well known that it tracks a target stably using a beacon mode. But it may fail to track a target in a certain region using a beacon mode. In this paper, we modeled a simple missile shape similar to ATCMS with two beacon antenna and analyzed an antenna radiation pattern using MLFMM(Multi Level Fast Multipole Method) method. Using the analyzed result of the radiation pattern of the antenna and the attitude data of target, we simulated beacon tracking performance of an instrumentation radar. As a result of simulation, we showed that an instrumentation radar may lose the target because it tracks a area of the beacon antenna pattern.

시선속도 변환과 불확도 전파에 관한 연구

류충호,황규환,장용식,김문기,최익환,Ryu, Chung-Ho,Hwang, Gyu-Hwan,Jang, Yong-Sik,Kim, Moon-Ki,Choi, Ik-Hwan 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.2

In general, radial velocity of a target can be obtained by acquiring doppler frequency shift in case of a doppler radar, or can be obtained by acquiring range rate in case of a pulse radar. Then radial velocity can be converted to tangential velocity using aspect angle or position variation per unit time. These two ways have the same meaning in physically, but result in different uncertainty finally. In this paper, it is described not only the two transformation procedures to calculate tangential velocity from radar measurement data, but also the result of combined uncertainty comparison between these two procedures.

3단계 발효에 의한 콩 알레르기성의 저하

류충호(Chung-Ho Ryu),이정옥(Jeong-Ok Lee),손대열(Dae-Yeul Son) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.8

In this study we investigated the change in antigenicity and allergenicity of Meju, a traditional Korean soybean product, by fermentation via 3 different microorganisms. The steamed soybeans were fermented with Lactococcus lactis subsp. lactis and/or Aspergillus oryzae and/or Bacillus subtilis. Proteins in soybean were degraded after fermentation. Antigenicity or allergenicity were analysed by immunoblotting and ELISA using soybean protein-specific polyclonal antibodies or soybean allergic patient sera. The best degradation was achieved by three step fermentation using nisin-producing Lactococcus lactis subsp. lactis IFO12007, A. oryzae and B. subtilis. Allergenicity and antigenicity were also starkly reduced after three step fermentation. The three-step fermentation method developed in our lab suggests an excellent alternative to reduce the allergenicity of soybeans.

CW 도플러 레이더의 시각 분해능과 시선 속도 정확도의 관계

류충호(Chung-Ho Ryu),장용식(Yong-Sik Jang),최익환(Ik-Hwan Choi) 한국전자파학회 2012 한국전자파학회논문지 Vol.23 No.7

CW 도플러 레이더는 움직이는 물체의 속도에 비례하는 도플러 주파수 편이를 검출함으로써 속도를 계측한다. 도플러 주파수 편이를 검출하기 위해서 시간영역에서 획득한 수신 신호를 주파수 영역으로 변환하기 위한 FFT(Fast Fourier Transform)를 수행한다. 이때 FFT 개수에 의해 도플러 레이더의 시각 분해능이 달라진다. 또한, FFT 개수는 수신 신호의 신호 대 잡음비에도 영향을 미치므로, 결국 시선 속도의 정확도와도 관련 있다. 따라서 본 논문에서는 FFT 개수에 따라 달라지는 시각 분해능과 시선 속도 정확도의 관계를 제시하였다. A CW Doppler radar can measure radial velocity of an object. It detects a Doppler frequency shift that is proportioned to radial velocity of a moving object. To detect a Doppler frequency shift, FFT(Fast Fourier Transform) is conducted. In this process, the time domain received signal is transformed to a frequency domain. A number of FFT affects not only the time resolution but also signal to noise ratio of received signal. So finally it is related with a radial velocity accuracy. Therefore in this paper, it is described the relation of time resolution and the radial velocity accuracy.

시험업무에 대한 CMMI 공학 프로세스 분야 모델링 연구

최주호,류충호,장용식,김흥범,Choi, Ju-Ho,Ryu, Chung-Ho,Jang, Young-Sik,Kim, Heung-Bum 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.2

DSTC(Defense Systems Test Center) in ADD(Agency for Defense Development) performs a test for various kinds of weapon system. In order to provide accurate test measurement data relating to the weapon system's performance with customer, A reliable test process and an objective analysis of the measurement data are required. DSTC is trying to apply CMMI(Capability Maturity Model Integration) Ver 1.2 in a test process. In this paper, we present the result of CMMI Engineering Process Area Modelling of Test Process.

표적 특성에 따른 모노펄스 레이더 불확도 연구

장용식,류충호,김환우,Jang, Yong-sik,Ryu, Chung-ho,Kim, Whan-woo 한국정보통신학회 2017 한국정보통신학회논문지 Vol.21 No.1

일반적으로 모노펄스 레이더의 오차 수준은 다중경로 간섭, 글린트, 동적 지연오차 등의 환경적 오차 요인이 제거된 이상적인 경우를 가정하고 있다. 따라서 지금까지는 외부 환경적 오차 요인이 포함된 모노펄스 레이더의 계측 불확도를 추정하여 왔다. 본 연구에서는 각기 다른 특성의 표적에 대해서 어떤 종류의 오차 요인이 모노펄스 레이더 계측 불확도 에 영향을 미치는지 살펴보았다. 이를 실험적으로 증명하기 위해서 먼저 환경적 오차 요인이 완벽히 제거된 이상적인 환경에서의 모의 실험 결과를 기술하였다. 이 결과와 함께 지상에 고정된 교정장치, 저속으로 기동하는 교정구, 고속으로 기동하는 비행표적에 대한 불확도를 추정함으로써 오차 요인이 포함된 각기 다른 특성의 표적에 대한 모노펄스 레이더 계측 불확도를 정량적으로 비교 고찰하였다. In general, an error budget of monopulse radar is proposed by manufacturer who assuming that all of external enviromental error resources such as multipath, glint, dynamic lag variation are removed. So until now, a measurement uncertainty of monopulse radar can be discussed including external enviromental error resources. In this paper, it is described that which kinds of error resource can effect on monopulse radar measurement uncertainty for different target property. To prove it experimentally, at first a simulation result is described assuming that all of external enviromental error resources are removed. It only includes receiver thermal noise. And then, monopulse radar measurement uncertainty estimation results tracking on calibration target which is fixed on specific position, calibration sphere which is moving slowly, weapon systems firing test which is moving fast are described quantitativly. All of these targets have different dynamic property.

계측레이더 추적 시뮬레이터 개발

예성혁,류충호,황규환,서일환,김형섭,Ye, Sung-Hyuck,Ryu, Chung-Ho,Hwang, Gyu-Hwan,Seo, Il-Hwan,Kim, Hyung-Sup 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.3

Defense Systems Test Center in ADD supports increasingly various missile test requirements such as higher altitude event, multi target operation and low-altitude, high velocity target tracking. In this paper, we have proposed the development of instrumentation radar tracking status simulator based on virtual reality. This simulator can predict the tracking status and risk of failure using several modeling algorithms. It consists of target model, radar model, environment model and several algorithms includes the multipath interference effects. Simulation results show that the predict tracking status and signal are similar to the test results of the live flight test. This simulator predicts and analyze all of the status and critical parameters such as the optimal site location, servo response, optimal flight trajectory, LOS(Line of Sight). This simulator provides the mission plan with a powerful M&S tool to rehearse and analyze instrumentation tracking radar measurement plan for live flight test at DSTC(Defense Systems Test Center).

무기체계 실사격 시험의 시스템공학 적용

유병직,황규환,류충호,김문기,예성혁,한욱상,Yoo, Byung-Jik,Hwang, Gyu-Hwan,Ryu, Chung-Ho,Kim, Moon-Ki,Ye, Sung-Hyuck,Han, Uk-Sang 한국군사과학기술학회 2012 한국군사과학기술학회지 Vol.15 No.1

We propose the live fire test process model based on systems engineering which consists of 4 phases i.e., review, setup, conduct and result. We also suggest the 4 phases acquisition model consisting of planning, execution, evaluation and disposal for test infrastructure. CMMI, TMMi and PMBOK are referred and hierarchial analysis method are adopted in developing the models. Thus, the detailed sub-processes are designed after defining higher level processes first. The higher level processes are defined by extracting common areas of all the test types. The low level processes for each specific test are designed by tailoring the higher level processes. By applying the proposed test process models into collaboration tool and information system, effective and systematic test processes for weapon systems are established.

자탄 분산에 대한 도플러 레이다 신호 시뮬레이션

서진배(Jinbae Suh),류충호(Chungho Ryu),양재원(Jaewon Yang),정용인(Yong-In Jung),유경우(Kyungwoo Yoo),전주환(Joohwan Chun) 한국전자파학회 2021 한국전자파학회논문지 Vol.32 No.7

다수 표적군에 대한 도플러 레이다 수신신호를 시뮬레이션하기 위해서는 표적군을 이루는 개별 표적의 공기역학적 운동에 대한 모델링이 필요하다. 자탄이 탑재된 무기체계는 자탄이 방출되면서 다수 표적군을 형성한다. 본 논문에서는 자탄을 가지고 있는 무기체계 중에서 모탄에 탑재된 자탄 형상이 기하학적으로 표현하기에 쉽고, 개수가 작으며, 그리고 상대적으로 근거리에서 도플러 신호 측정이 가능한 다수의 대전차 지뢰들의 운동을 모델링하여 이들의 위치와 속도를 찾고, 이로부터 도플러 레이다 신호를 모사하였다. To accurately simulate signals scattered by multiple targets and received by Doppler radar, target motion under aerodynamic forces has to be modeled. We present a new technique for computing aerodynamic forces acting on flying mines of remote anti-armor mine systems (RAAMS). This weapon system is particularly attractive for detailed analysis of multiple clustered sub-munition systems, owing to their simple shape and relatively small number. The generated positions and velocities of multiple mines are then used to generate the radar echo signal received by the Doppler radar.

Nisin 생성 유산균을 이용한 저염 된장의 제조

이정옥(Jeong-Ok Lee),류충호(Chung-Ho Ryu) 한국식품영양과학회 2002 한국식품영양과학회지 Vol.31 No.1

된장 제조과정 중 불쾌취와 점질물을 생성하는 부패균인 B. subtilis의 생육억제를 위해 nisin을 생성하는 L. lactis subsp. lactis ATCC 7962, ATCC 11454, IFO 12007을 이용하여 유산발효를 수행하여 pH변화, B. subtilis의 생육저해도 등을 검토하였다. 증자콩에서 nisin 생성유산균들의 생육특성을 살펴본 결과, 세 가지의 균주 모두가 증자대두 1 g 당 10^6 CFU 접종하여 24시간 이내에 10^9 CFU로 급격하게 자라므로 영양요구성이 복잡한 유산균이 증자대두에서 다른 영양소의 첨가없이도 잘 생육함을 확인하였다. 증자콩에서 7962와 11454는 생육에 따라 pH가 급격히 저하되어 된장발효용 종균으로 사용할 수 없었다. 증자한 콩 중에 잘 증식하고 유산발효 후 pH 변화가 완만한 12007을 된장발효의 종균으로 전혀 문제점이 없어 사용시 부패균인 B. subtilis의 생육이 효과적으로 저해됨이 확인되었다. 생성된 nisin은 황국균이 생성하는 protease에 의해 분해되며 콩 속에 다량으로 존재하던 유산균은 사입시 첨가되는 식염으로 불활성화되거나 사멸하여 된장의 산패를 막아준다. 그리고 8% 식염을 첨가하여 된장 제조시, 즉 저염 된장 제조시 B. subtilis의 생육이 효과적으로 억제되고 다수로 존재하던 유산균은 담금 후 점차 줄어들어 시간경과 후에는 관찰되지 않았다. 8%함유 식염된장의 숙성 중 pH 변화 역시 12% 함유 식염된장과 유사한 값을 나타내었다. The growth inhibition by nisin-producing lactococci against Bacillus subtilis and its application to doenjang fermentation were investigated. Lactococcus lactis subsp. lactis IFO 12007, L. lactis subsp. lactis ATCC 7962 and L. lactis subsp. lactis ATCC 11454 were used as nisin-producing lactococci. All of three strain rapidly proliferated to more than 10^9 CFU/g in steamed soybeans. Only L. lactis subsp. lactis IFO 12007 was in steamed soybeans without any pH decrease. In spite of the mild decrease in pH, the growth of B. subtilis was completely inhibited; no living cells were detected in a soybean sample inoculated with 10^6 CFU/g and incubated for 24 to 72 h. The L. lactis subsp. lactis IFO 12007 was applied to doenjang fermentation as a starter culture. It produced high nisin activity in steamed soybean, resulting in the complete growth inhibition of B. subtilis, which had been inoculated at the beginning of the meju fermentation, throughout the process of doenjang production. Over-acidification, which is undesirable for doenjang quality, was successfully prevented simply by adding salt which killed the salt-intolerant L. lactis subsp. lactis IFO 12007. Furthermore, the nisin activity in doenjang disappeared with aging. The growth inhibition by nisin-producing lactococci against Bacillus subtilis and its application to doenjang fermentation were investigated. Lactococcus lactis subsp. lactis IFO 12007, L. lactis subsp. lactis ATCC 7962 and L. lactis subsp. lactis ATCC 11454 were used as nisin-producing lactococci. All of three strain rapidly proliferated to more than 10^9 CFU/g in steamed soybeans. Only L. lactis subsp. lactis IFO 12007 was in steamed soybeans without any pH decrease. In spite of the mild decrease in pH, the growth of B. subtilis was completely inhibited; no living cells were detected in a soybean sample inoculated with 10^6 CFU/g and incubated for 24 to 72 h. The L. lactis subsp. lactis IFO 12007 was applied to doenjang fermentation as a starter culture. It produced high nisin activity in steamed soybean, resulting in the complete growth inhibition of B. subtilis, which had been inoculated at the beginning of the meju fermentation, throughout the process of doenjang production. Over-acidification, which is undesirable for doenjang quality, was successfully prevented simply by adding salt which killed the salt-intolerant L. lactis subsp. lactis IFO 12007. Furthermore, the nisin activity in doenjang disappeared with aging