• Journal of the Korean Society of Propulsion Engineers
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• 제17권6호
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• pp.38-47
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• 2013

Traditional propellants release toxic gases during combustion that are harmful to the environment. This study describes a novel synthetic process of two high nitrogen containing tetrazines, TATTz and BTATz, which can be adapted as solid fuels for a solution to environmental concerns. The compounds were characterized by NMR, IR spectroscopy, and differential scanning calorimetry(DSC). Detonation properties were calculated with the EXPLO5 program based on calculated heats of formation and measured densities.

• Journal of the Korean Society of Propulsion Engineers
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• 제23권1호
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• pp.9-14
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• 2019

Hydroxy-terminated polybutadiene (HTPB) propellants of solid rocket motors age differently under different storage temperatures. The shelf life of a solid rocket motor depends on the aging ratio of the HTPB propellant; it can be estimated through the viscoelastic properties by an aging test. This study analyzed the initial and natural aging properties during long-term storage. The initial properties were obtained from characterization and accelerated test results. The test results were obtained by analyzing the strain on cylindrical grains when a thermal load was applied.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.574-581
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• 2011

A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2- DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.

• Journal of the military operations research society of Korea
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• 제34권1호
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• pp.47-59
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• 2008

This paper deals with an empirical study to statistically analyse various business performance on research and development(R&D) as an independent variables. The major results of statistical analyses have come up with the followings : First, the regression analyses between the growth rate and the opportunity of education showed the positive relationship. Second, the regression analyses between the productivity and the expenses of R&D showed the positive relationship. Third, the regression analyses between the profit and the mutual cooperation showed the positive relationship.

• Journal of the Korean Society of Systems Engineering
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• 제17권1호
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• pp.35-42
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• 2021

Recent defense R&D projects have been required as weapons systems applied with advanced technology considering exports. As a result, the complexity of the applied technology increases, and the risk of system development increases. Under these circumstances, an effectives method of performing evolutionary development for economical and timely deployment is presented. To this end, we hope that this study, which proposed the maintenance of related laws and measures for realistic and active evolutionary development, will help the R&D of the weapons systems.

• Journal of the Korea Institute of Military Science and Technology
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• 제20권6호
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• pp.844-852
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• 2017

Since guided weapon is high-cost and one-shot device which is non-reusable, it requires a lot of resources to prove required accuracy as a part of reliability demonstration. Once a test for proving accuracy rate of guided missile fails, it causes an additional cost and delay of schedule. This study introduces an equation for proper sample size and plan for guided-missile accuracy rate test in order to minimize the risk of test failure. Proper sample size for the test is derived by considering the reliability growth. Furthermore, each task for accuracy rate test is defined according to the development step. Therefore, this study can contribute to reduce sample size for accuracy rate test in order to meet the reliability requirement and assure transparency in the test process.

• Journal of Information Technology Services
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• 제14권4호
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• pp.45-60
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• 2015

Governments around the world invest in research and development (R&D) for different purposes : national economy, defence, environment, health, etc. as a means of national survival beyond the means of national competitiveness. These are usually programs with high social impact but low short-term economic impact or large scientific programs that are too expensive and risky for private sector investment alone. The Republic of Korea has also shown a very successful model of economic progress and social development through government R&D programs. However, there have been many corruption scandals behind it while selecting awardees for government R&D programs in Korea. So, the Republic of Korea focused on reforming appraisal system for government R&D and began preparation for "Clean Appraisal System" last year. In this study, first we analyzed the related appraisal tasks through the review of laws and administrative rules and typed appraisal tasks according to the flow of the actors and time. Thus securing the information infrastructure and finally we drew the conceptual model of the system according to an open appraisal tasks by introducing an element of the OECD on open government typed appraisal tasks.

• Journal of the Korean Data and Information Science Society
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• 제23권5호
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• pp.961-970
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• 2012

To evaluate companies that participated in the defense R&D project, 27 variables are chosen through literature survey, feature analysis of defense R&D and interviews with military experts. 17 variables are selected after factor analysis which is applied to reduce the number of variables and to detect structure in the relationships among variables, that is to classify variables using Likert-type scales. And then 17 variables are prioritized by AHP (analytic hierarchy process) method. It is shown that communication skill & cooperation strategy, level of technology, possession of needs technology have high priorities. However, protection plan of technology leakage, expertise of subcontractors, software development plan have low priorities.

• Journal of the Korean Society of Propulsion Engineers
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• 제19권4호
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• pp.69-76
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• 2015

Recently, environmental sustainability of the transitional explosives and propellants is an issue of growing importance in energetic materials. For examples, ammonium perchlorate(AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, hydrazinium nitroformate(HNF) is an effective candidate substance for eco-friendly oxidizer, which has high density, pressure index, and less smog generating property during combustion for the Divert and Attitude Control System(DACS). This study was confirmed a synthesis through various conditions, was performed for the essential data of solubility the crystallization process. Also, crystallization process such as cooling, drowning-out and sonication were performed.

• Journal of the Korean Society of Propulsion Engineers
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• 제22권3호
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• pp.119-127
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• 2018

A test stand for an altitude test of reciprocating engine was designed, manufactured and validated by preliminary tests and simple calculations. The test stand was designed to interface with the altitude turbo-shaft engine test facility of Korea Aerospace Research Institute. Many limiting conditions for altitude test of reciprocating engine were assumed and the test stand was developed to satisfy these limitations. The test stand design was focused especially on the altitude, Mach number and fuel temperature control for reciprocating engine altitude tests with smaller air and fuel flow than those of turbo shaft engines.