• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.4
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• pp.40-49
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• 2001

The basic research on AKM(Apogee Kick Motor) for space launch vehicle was carried out. AKM which will be used as 3rd stage solid rocket motor in 3-stage Korean Sounding Rocket(III) has been developing. KM is a solid rocket motor using composite propellant based on HTPB and is composed of composite motor case and submerged nozzle. To develop KM rocket motor satisfing a given set of requirement, firstly the full-scale KM with diameter 520mm was designed, then sub-scale motors reduced about 60% were manufactured and tested. Full-scale ground firing test is accomplished two times.

• Bulletin of the Korean Space Science Society
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• 1993.10a
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• pp.11-11
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• 1993

The Korean sounding rockets(KSR) 1, 2 equigped with the UV optical detectors have been launched at An-heung, Chungchongnam-do, of June 4 and September 1, 1993,respectively. The UV detector is used to measure the attenuation of solar UV radiation for various frequency bards in the stratospgere. We obtained the profile of the ozone number density within the altitulde of 15 - 30 km by applying the Beer-Lambert law. It is found that the maHimum of the ozone distribution occurs near 2sht which is quite consistent with the mean value in the mid-latituderegions. We will also compare our results froiu KSR 1,2 with the other observational data from the Dobson speceo meter at Yonsei Univ. and the LIDAa which were performed simultaneously with the sounding rocket experiments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.364.2-364
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• 2002

Thermoacoustic oscillation, which stems from phase correlation between unsteady heat release and acoustic fluctuation, can cause severe vibration and incite the excessive local heat transfer inside the rocket engine. It is very important to understand and prevent this phenomenon in the way of rocket engine development. In this study, the propulsion test facility of KSR-III, which is the first liquid propellant rocket developed by KARI, will be introduced. and the characteristics of thermoacoustic ocillation occurred at the facility will be examined.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.171-181
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• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.

• Korean Journal of Radiology
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• v.25 no.7
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• pp.613-622
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• 2024

Objective: In Korea, radiology has been positioned towards the early adoption of artificial intelligence-based software as medical devices (AI-SaMDs); however, little is known about the current usage, implementation, and future needs of AI-SaMDs. We surveyed the current trends and expectations for AI-SaMDs among members of the Korean Society of Radiology (KSR). Materials and Methods: An anonymous and voluntary online survey was open to all KSR members between April 17 and May 15, 2023. The survey was focused on the experiences of using AI-SaMDs, patterns of usage, levels of satisfaction, and expectations regarding the use of AI-SaMDs, including the roles of the industry, government, and KSR regarding the clinical use of AI-SaMDs. Results: Among the 370 respondents (response rate: 7.7% [370/4792]; 340 board-certified radiologists; 210 from academic institutions), 60.3% (223/370) had experience using AI-SaMDs. The two most common use-case of AI-SaMDs among the respondents were lesion detection (82.1%, 183/223), lesion diagnosis/classification (55.2%, 123/223), with the target imaging modalities being plain radiography (62.3%, 139/223), CT (42.6%, 95/223), mammography (29.1%, 65/223), and MRI (28.7%, 64/223). Most users were satisfied with AI-SaMDs (67.6% [115/170, for improvement of patient management] to 85.1% [189/222, for performance]). Regarding the expansion of clinical applications, most respondents expressed a preference for AI-SaMDs to assist in detection/diagnosis (77.0%, 285/370) and to perform automated measurement/quantification (63.5%, 235/370). Most respondents indicated that future development of AI-SaMDs should focus on improving practice efficiency (81.9%, 303/370) and quality (71.4%, 264/370). Overall, 91.9% of the respondents (340/370) agreed that there is a need for education or guidelines driven by the KSR regarding the use of AI-SaMDs. Conclusion: The penetration rate of AI-SaMDs in clinical practice and the corresponding satisfaction levels were high among members of the KSR. Most AI-SaMDs have been used for lesion detection, diagnosis, and classification. Most respondents requested KSR-driven education or guidelines on the use of AI-SaMDs.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.39-45
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• 2000

Hypersonic analysis on the KSR-III payload configuration has been performed using an axisymmetric Navier-Stokes code. A numerical code based on the Harten and Yee's upwind TVD scheme with simplified curve fits in the equilibrium chemically reacting air was developed. The carbuncle phenomenon on detached shock in front of the payload is controlled by using pressure gradients to tune the dissipation. Equilibrium chemically reacting computations for reentry flight conditions of Mach no. 10.2, 8, 4.9 are presented and compared with the results of calorically perfect gas.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1343-1346
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• 2008

$KSrPO_4$ and $Sr_3(Al_2O_5)Cl_2$ phosphors doped with $Eu^{2+}$ emit a blue and orange-yellow luminescence under ultraviolet (UV) excitation at ~ 400 nm, respectivel, which can be used for making white light emitting diodes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.384.1-384
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• 2002

Rocket propulsion systems generate very high level noise (acoustic loads), which is due to supersonic jet of rocket propulsion system. In practice, the sound power level of rocket propulsion systems is over 180 ㏈. This high level noise excites rocket structures and payloads, so that it causes the structural failure and electronic malfunctioning of payloads. Prediction method of acoustic loads of rocket enables us to determine the safety of payloads. (omitted)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.5-5
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• 1999

3단형 과학로켓(KSR-III)의 기본형 및 응용형에 공통으로 사용되는 주엔진은 액체산소를 산화제로, 케로신을 연료로 사용하는 액체추진기관이다. 엔진 기본설계를 통하여 로켓 임무 요구사항에 부합되도록 엔진 각 부분의 기본제원을 설정하였고, 엔진의 형상을 결정하였다. 설계된 엔진의 성능검증 작업은 분사시험용 엔진, 축소형 엔진, 엔지니어링 모델 및 비행시험모델의 설계/제작/시험을 통하여 순차적으로 수행할 계획이다. 본 연구는 3단형 과학로켓 엔진의 기본설계 및 성능검증 계획에 관한 것이다.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2656-2658
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• 2002

로켓과 지상장비의 각 모듈 사이에서 교환되는 데이터와 제어 정보, 상호작용 등을 정확하게 기술하기 위해 UML 객체 지향 방법을 이용해서 로켓 발사시스템을 모델링한다. 이렇게 만들어진 상위레벨 객체 모델을 기반으로 해서 발사통제 시스템에서 지시하는 명령들의 시퀀스로서 발사 시나리오를 구성한다. 본 논문의 UML 객체 다이어그램과 발사 시퀀스 다이어그램은 로켓과 지상장비를 운영하고 통제하는 다양한 작업에 유용하게 사용될 수 있다.