• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.77-83
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• 2021

In the current study, the numerical method was established to predict the performance of a solid rocket motor with two kinds of propellants. On the basis of a numerical study, an internal ballistics analysis code was developed. To verify the internal ballistics analysis code two solid rocket motors were manufactured and tested. The accuracy and applicability of the internal ballistics code for dual-propellant solid rocket motor were verified by comparing the experimental results with the numerical calculation.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.171-172
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• 2013

본 연구에서는 국내 화재시험기관에 3개소에 설치되어 있는 룸코너 시험기에 대하여 시험소간 비교시험을 수행하고 결과를 정리하였다. 비교시험에 사용된 표준시료의 제작 절차, 비교시험 수행 방법 및 각 평가결과에 대하여 소개하고자 한다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.339-345
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• 1996

배관 및 기기 등의 지지부 정착에 사용되는 확장형 앵커는 여러 종류의 진동하중을 받게 되므로 그러한 하중에 대한 동적저항능력이 시험에 의하여 확인되어야 한다. 확장형 앵커의 동적시험 요건이 ASTM E488에 기술되어 있으나 내진시험 입력, 피로전단시험 입력 등 일부 요건이 구체적으로 명시되어 있지 않아 시험기관에 따라 시험조건이 자의적으로 결정될 수 있다. 따라서, 본고에서는 코드 시험요건이 구체적이지 못한 사항을 조사하여 적정 요구수준을 제시하였다. 또한, 국내에서 수행된 동적시험내용 검토결과, 현행 동적설계방안의 일부보완이 필요함을 확인하였다.

• Tribology and Lubricants
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• v.2 no.1
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• pp.18-29
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• 1986

한국철도에서는 현재 약 450냥에 가까운 Diesel 기관차를 보유하고 있으며 기관의 정밀검사를 위한 Enginer의 Overhaul은 2Y검사로 2년마다 실시하고 있다. 원래 Engine의 Overhaul 주기간격은 Liner Bore와 Piston Ring 등 동력장치 조립체의 구성부품의 체험적인 마모율을 감안하여 결정되며 가장 경제적이면서도 무장애운행을 가능케 하는 것은 마모율이 최저로 유지되고 있을 때이다. 따라서 기관의 마모를 최대로 억제하는 것이 바람직하다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.492-500
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• 2018

The performance evaluation of cold weather clothing is mainly carried out with thermal resistance. However, the results of the revised test method regarding the same specimen were decreased compare to previous one. In addition, there were deviations of the results among the authorized testing institutes according to the different interpretation of the KS test method. This makes it a considerable difficulty to the quality assurance of combat supplies. The purpose of this study is to minimize the variation of the results before and after the revision by analyzing the cause of the decrease in the heat insulation rate according to the revised test method. For this purpose, the difference between the test conditions before and after the revision of KS is analyzed and the possible results are reviewed. In addition, we want to minimize the result deviation between testing laboratories by analyzing the cause of the result deviation between test laboratories according to arbitrary interpretation of the standard. Based on this, we propose a standardized test method to prevent the decrease of the heat insulation rate by checking the pre-revision test method and the condition with the least deviation.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.401-409
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• 2012

Ultrasonic testing are far superior to other nondestructive tests for detecting the disbond interface which occurred in adhesive interface. However, a solid rocket motor consisting of a steel case, rubber insulation, liner, and propellant poses many difficulties for analyzing ultrasonic waves because of the superposition of reflected waves and large differences in acoustic impedance of various materials. Therefore, ultrasonic tests for detecting the disbond interface in solid rocket motor have been applied in very limited areas between the steel case and rubber insulation using an automatic C-scan system. The existing ultrasonic test cannot detect the disbond interface between the liner and propellant of a solid rocket motor because most of the ultrasonic waves are absorbed in the rubber material which has low acoustic impedance. This problem could be overcome by analyzing the resonance frequency from the frequency spectrum using the ultrasonic resonance method. In this paper, a new technique to detect the disbond interface between the liner and propellant using ultrasonic resonance characteristics is discussed in detail.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.24-25
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• 2000

실제 추진기관에서 비추력 성능에 미치는 열/유동현상은 이상 유동(ideal flow)과는 달리, 추진기관의 특성에 따라 다양한 열/유동손실이 나타나며, 연소시험 시에는 이러한 성능 손실 인자들이 복합적으로 작용하여 나타나는 추력이 측정된다. 따라서 임의의 추진기관을 새롭게 성능 설계할 때에 부딪히는 문제중의 하나는 추력 손실 양을 정량화 시키는 일이다. 그런데 고체 추진기관은 복잡한 물리적인 현상들이 복합되어 작동되기 때문에 lump parameter로 간단히 추력 손실을 예측하는 것은 매우 어려운 일이다.(중략)

• Journal of Radiation Protection and Research
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• v.21 no.3
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• pp.147-153
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• 1996

The Korea Atomic Energy Research Institute(KAERI) conducted a intercomparison study for personnel dosimetry services in Korea to enhance the accuracy and precision of the dosimetry system. Nine types of dosimeters(6 TLD, 3 film badge) from 7 institutions took part in this intercomparison study. Each participant submitted 30 dosimeters including transit control for irradiations. Both TLDs and film badges were irradiated with Cs-137 gamma, Sr/Y-90 beta and 4 X-ray beams in ISO wide series. Four dosimeters were irradiated on phantom with same dose equivalent for each field category. The delivered dose equivalent was in the range of $0.1{\sim}10mSv$. The participants assessed the results of their dosimeter readings in terms of the ICRU operational quantities for personal monitoring, Hp(10) and Hp(0.07). Most participants except 1 dosimeter estimated the delivered dose equivalent with biases less than ${\pm}25%$ for Cs-137 and Sr/Y-90. But for X-rays, the biases exceeded ${\pm}35%$ in some cases bacause the dose evaluation algorithm was based on the ANSI N13.11 X-ray fields which are different from those given by ISO.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.429-432
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• 2014

국내 제약산업의 경쟁력을 제고시키기 위해서는 신약의 심사/허가 기간을 단축시켜 급변하게 변하는 글로벌 제약시장에서 경쟁 우위적 위치를 선점할 수 있도록 기회를 제공할 수 있도록 체계 개선이 시급하다. 신약허가를 위해서는 임상시험 결과에 대한 안전성과 유효성 등에 대한 심사가 수행되게 된다. 하지만 현재 신약허가를 위해서 제약사와 임상시험수탁기관(Contract Research Organization, CRO)에서 데이터 정보체계인 Domain, Variable 및 Parameter 등의 표준을 따르지 않고 다양한 유형의 임상정보데이터를 심사기관에 제출하고 있어 이로 인한 심사기간 증가와 심사업무 비효율성을 야기시키고 있다. 따라서 본 연구에서는 국제민간기구인 CDISC (Clinical Data Interchange Standards Consortium)에서 제정한 글로벌 임상데이터 표준인 CDISC 표준을 준용한 국내 임상시험정보관리 체계 (eCTD 시스템)및 의약품 전주기적 관리체계를 제시하고자 하며, 본 연구를 통한 기대효과로는 국제표준의 임상정보관리 인프라 구축으로 인한 국내 신약개발 및 해외 진출 환경을 마련하여 글로벌 시장선점의 기회를 제공할 수 있고, 규제기관 차원에서는 의약품 허가, 심사업무의 효율성 증가는 물론 전주기적 의약품 안전관리체계를 마련할 수 있을 것으로 사료된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.144-147
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• 2017

A hybrid rocket engine capable of thrust throttling and underwater-working was developed for the underwater high-speed vehicle propulsion system. The hybrid rocket engine was designed and made by two types of ground test motor and underwater working motors. An engine performance was verified by the ground tests with the ground test motor and in the case of underwater motors the ground tests and underwater tests were performed. For the underwater operation a two-stage ignition system was adopted and a rupture disc was installed at the end of nozzle for a water-tight just before an ignition. Successful ignition and propulsion were confirmed in the underwater test with the final selected double rupture disc.