명령어 집합 시뮬레이터를 이용한 임베디드 소프트웨어 디버거

정훈,손성훈,신동하,Jung, Hun,Son, Sung-Hoon,Shin, Dong-Ha 한국시뮬레이션학회 2006 한국시뮬레이션학회 논문지 Vol.15 No.4

임베디드 소프트웨어의 디버깅은 일반 소프트웨어의 디버깅과는 많이 다르다. 예를 들어 임베디드 소프트웨어 디버깅에는 일반 소프트웨어의 디버깅에는 필요하지 않는 전력 소비량에 대한 정보, 실행된 명령어 분포에 대한 정보, 사용된 레지스터 분포에 대한 정보, 프로그램 수행 시 소요된 클럭 수에 대한 정보 등이 추가적으로 더 필요하다. 본 논문은 임베디드 소프트웨어가 수행되는 마이크로프로세서의 명령어 집합 시뮬레이터를 이용하여 임베디드 소프트웨어를 효과적으로 디버깅하는 새로운 방법을 제안한다. 본 연구에서는 국산 임베디드 마이크로프로세서인 SE1608의 명령어 집합 시뮬레이터를 기반으로 디버거를 개발하고 이를 사용하여 임베디드 소프트웨어 벤치마크 프로그램으로 많이 이용되는 MiBench 프로그램을 사용하여 임베디드 소프트웨어를 효과적으로 디버깅하는 보기를 제시한다. 본 연구에서 제시한 디버깅 방법은 기존의 디버깅 방법에 비하여 비교적 구현하기도 쉬우면서 많은 장점이 있는 것으로 판단된다. Debugging embedded softwares is very different from debugging general softwares. For examples, debugging embedded software requires more information, such as information on power consumption, information on the distribution of executed instructions, information on the distribution of used registers, and information on the amount of clocks consumed during the execution of a program, that is not needed in debugging general softwares. In this paper, we propose more effective method fer debugging embedded softwares using an instruction set simulator for the microprocessor that is executing embedded softwares. In this research, we develop a debugger based on an instruction set simulator for a domestic embedded microprocessor called SE1608 and we shows an effective debugging method using a MiBench program which is widely used to benchmark embedded softwares. The debugging method proposed in this paper is relatively easy to implement and shows many advantages compared with existing debugging methods.

Analytical Structural Integrity for Welding Part at Piping Penetration under Seismic Loads

Hun-Oh Choi(최헌오),Hoon-Hyung Jung(정훈형),Chae-sil Kim(김재실) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.1

The purpose of this paper is to assess the structural integrity of piping penetrations for nuclear power plants. A piping qualification analysis describes loads due to deadweight, pressure difference acts normal to the plate, thermal transients, and earthquakes, among other events, on piping penetrations that have been modeled as an anchor. Amodel was analyzed using a commercial finite element program. Apiping penetration analysis model was constructed with an assembly of pipe, head fittings and sleeves. Normally, the design load, thus obtained, will consist of three moments and three forces, referred to a Cartesian coordinate system. When comparing the stress analysis results from each required cutting position, the general membrane stress intensities and local membrane plus bending stress intensities during a structural evaluation cannot exceedthe allowable amount of stress for the design loads. Therefore, the piping penetration design satisfies the code requirements.

추력실 길이변화가 70 N급 하이드라진 추력기의 펄스모드 성능에 미치는 영향

정훈(Hun Jung),김종현(Jong Hyun Kim),김정수(Jeong Soo Kim),배대석(Dae Seok Bae) 한국추진공학회 2013 한국추진공학회 학술대회논문집 Vol.2013 No.12

우주비행체의 주 엔진 및 자세제어용 엔진으로 적용 가능한 70 N급 하이드라진 추력기의 추력실 최적설계형상 도출을 위한 지상연소시험을 수행하였다. 추력실 압력 및 온도, 하이드라진 분해반응률, 임펄스 비트, 그리고 비추력 등이 추력실 길이변화에 따라 고찰되고, 시험모델의 응답특성이 제시된다. 개발모델은 매우 우수한 펄스 응답성능과 재현성을 보였고, 시험조건 내에서의 촉매대 길이증가는 추력기의 성능저하를 야기하는 것이 확인되었다. A ground hot-firing test was conducted to take out the optimal design configuration for the thrust chamber of 70 N-class hydrazine thruster, which could be used for primary engine or reaction control engine of space vehicles. Performance characteristics with the variation of thrust-chamber length are examined in terms of chamber pressure and temperature, hydrazine decomposition rate, impulse bit, and specific impulse. In addition to that, response characteristics of test models are scrutinized, oo. It is revealed through the test and evaluation that pulse response and repeatability of the development model show excellent characteristics, and the increase of catalyst-bed length leads to a performance degradation in the test condition specified.

말더듬인의 후두 행동 및 음향학적 특성 연구

정훈(Hun Jung) 한국언어치료학회 2014 言語治療硏究 Vol.23 No.2

Purpose: The abnormal laryngeal behaviors observed in the utterances of people who stutter (PWS) are believed to be directly associated with stuttering. The objectives of this study were to find laryngeal behaviors of PWS, acoustic characteristics of PWS, and provide the basic information necessary to develop a stuttering treatment method. Methods: To investigate the laryngeal behaviors of PWS and acoustic characteristics, we sampled 25 PWS, 26 people with muscle tension dysphonia (PMTD), which is a representative communication disorder causing speech production through excessive tension in the larynx, and 28 people who do not stutter (NS), and compared the groups. Laryngeal behavior characteristics were compared among the groups in terms of supraglottis movement and vocal fold vibration, and acoustic characteristics were compared in terms of fundamental frequency (F0), jitter, shimmer, and noise to harmonic ratio (NHR). Results: First, in the comparison of supraglottis movement among groups, significant difference was observed in false vocal compression. Second, in the comparison of vocal fold vibration among the groups, significant difference was observed in the glottical attack before phonation, the regularity of vocal cords, vocal fold contact quotient, and vocal fold vibratory start time. Third, in the comparison of acoustic characteristics among the groups, significant difference was observed in jitter, shimmer, and NHR. Among acoustic characteristics related to PSW however, only shimmer was significantly different. Conclusions: In conclusion, major laryngeal behaviors of PWS and acoustic characteristics include false vocal compression resulting from excessive tension on the supraglottical level, and excessive tension in glottical attack before utterance, vocal fold contact quotient, and vocal fold vibratory start time on the glottical level. Such glottical level tension may be explained with irregular vocal tension related to acoustic intensity and delayed vocal fold vibratory start time.

액체추진제 추력기 인젝터 분무액적의 2차원 공간분포

정훈(Hun Jung),김진석(Jin Seok Kim),김정수(Jeong Soo Kim),김성초(Sungcho Kim),박정(Jeong Park),장기원(Ki-Won Jang),서혁(Hyuk Su) 한국추진공학회 2007 한국추진공학회 학술대회논문집 Vol.2007 No.11

하이드라진 추력기의 촉매대 길이직경비에 따른 압력 불안정 특성

정훈(Hun Jung),김종현(Jong Hyun Kim),김정수(Jeong Soo Kim) 한국추진공학회 2014 한국추진공학회지 Vol.18 No.6

A ground hot-firing test (HFT) was carried out to make a close examination into the pressure instability for the 70 N-class hydrazine thruster under development. Monopropellant grade hydrazine was adopted as a propellant for the HFT, and catalyst-bed was filled with Ir/Al₂O₃ catalyst. In order to investigate the effects of thrust-chamber diameter on combustion stability, evaluation tests for the development models were performed on three kinds of lower thrust chambers having the length-to-diameter ratio (L/D) of 1.03, 1.13, and 1.26. As results, it was found that low frequency instability (~ 50 Hz) was inherent in the models, and in addition, increase of the L/D and decrease of the operating pressure led to an amplification of pressure oscillation in the test condition specified.

70 N급 하이드라진 추력기의 연소실 압력진동 강도와 추력 응답특성의 상관관계

정훈(Hun Jung),김정수(Jeong Soo Kim) 한국추진공학회 2015 한국추진공학회지 Vol.19 No.3

A ground hot-firing test(HFT) was accomplished to draw a correlation between the pressure oscillation intensity of combustion chamber and thrust response characteristics in a 70 N-class hydrazine thruster which has been developed recently. Monopropellant grade hydrazine was adopted as a propellant for the HFT, and combustion-chamber characteristic length, propellant injection pressure were applied as test parameters. It was confirmed that the decrease of thrust-chamber diameter and injection pressure augmented the pressure oscillation of stagnation chamber in the test condition specified, and the oscillation hampered the pulse response performance of test models.

우주발사체의 비행자세 3축 정밀제어를 위한 소형 액체로켓엔진의 펄스모드 응답특성

정훈(Hun Jung),김종현(Jong Hyun Kim),김정수(Jeong Soo Kim),배대석(Dae Seok Bae) 한국추진공학회 2013 한국추진공학회지 Vol.17 No.1

A liquid-monopropellant hydrazine thruster has several outstanding advantages such as relatively-simple structure, long/stable propellant storability, clean exhaust products, and so on. Therefore hydrazine thruster has such a wide application as orbit and attitude control system (ACS) for space vehicles. A hydrazine thruster with the medium-level thrust to be used in the ACS of space launch vehicles (SLV) has been developed, and its ground firing test result is presented in terms of thrust, impulse bit, temperature, and chamber pressure. It is verified through the performance test that the response and repeatability of thrust are very excellent, and the thrust efficiencies compared to its ideal requirement are larger than 93%.

추력실 길이에 따른 하이드라진 추력기의 저주파 연소불안정 특성

정훈(Hun Jung),김종현(Jong Hyun Kim),박재문(Jae Moon Park),배성훈(Seong Hun Bae),김정수(Jeong Soo Kim) 한국추진공학회 2014 한국추진공학회 학술대회논문집 Vol.2014 No.12

70 N급 하이드라진 추력기 개발모델의 압력 불안정 특성 고찰을 위한 시험평가가 수행되었다. 개발모델의 추력실 형상이 연소 안정성에 미치는 영향을 규명하기 위해, 하단 촉매대의 길이 변화에 따른 지상연소시험이 수행되었다. 성능평가 결과, 시험모델에서 저주파 압력 불안정 특성이 관찰되었으며 불안정성은 추력실 압력과 추진제 공급특성이 연계되어 발현되는 추진제 분무의 동적특성에 지배적인 영향을 받는 사실이 확인되었다. A test and evaluation was carried out to make a close examination into the combustion instability for the 70 N-class hydrazine thruster under development. In order to investigate the effects of thrust chamber configuration on combustion stability, ground hot-firing tests for the development models were performed with variation of lower catalyst-bed length. As a result, it was identified that low-frequency pressure instability appears in the test models. This instability was primarily affected by the dynamic nature of propellant spray which is consequence of coupling between thrust chamber pressure and propellant supply characteristic.

연소실 압력진동이 70 N급 하이드라진 추력기의 추력상승시간에 미치는 영향

정훈(Hun Jung),김정수(Jeong Soo Kim),김민성(Min Sung Kim),배성훈(Seong Hun Bae),배대석(Dae Seok Bae) 한국추진공학회 2015 한국추진공학회 학술대회논문집 Vol.2015 No.5

70 N급 단일액체추진제 추력기 개발모델의 연소실 압력진동 강도와 추력상승시간이 갖는 상관도 도출을 위해 지상연소시험을 수행하였다. 단일추진제급 하이드라진이 연소시험용 추진제로 선정되었고, 연소실의 특성길이와 추진제 분사압력이 시험변수로 적용되었다. 시험조건 내에서의 추진제 분사압력의 감소는 정체실의 압력진동을 증대시키고, 압력진동은 추력기의 응답성능을 저해하는 요소로 작용하는 것이 확인되었다. A ground hot-firing test (HFT) was accomplished to draw a correlation between the pressure oscillation intensity of combustion chamber and thrust rise time in a 70 N-class hydrazine thruster. Monopropellant grade hydrazine was adopted as a propellant for the HFT, and combustion-chamber characteristic length, propellant injection pressure were applied as test parameters. It was confirmed that the decrease of propellant injection pressure augmented the pressure oscillation in the test condition specified, and the oscillation hampered the response performance of the thruster.