• Safety and Health at Work
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• 제1권2호
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• pp.175-182
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• 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group ($HOCH_2CH_2$), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from $0.19\;mg/m^2{\cdot}min$ at $23.5^{\circ}C$ to $8.04\;mg/m^2{\cdot}min$ at $60^{\circ}C$. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was $0.45\;mg/m^3$ in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

• Toxicological Research
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• 제32권4호
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• pp.337-343
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• 2016

We determined the toxicity of mixtures of ethyl acetate (EA), isopropyl alcohol (IPA), methyl ethyl ketone (MEK), toluene (TOL) and xylene (XYL) with half-maximal effective concentration ($EC_{50}$) values obtained using human hepatocytes cells. According to these data, quantitative property-activity relationships (QPAR) models were successfully proposed to predict the toxicity of mixtures by multiple linear regressions (MLR). The leave-one-out cross validation method was used to find the best subsets of descriptors in the learning methods. Significant differences in physico-chemical properties such as boiling point (BP), specific gravity (SG), Reid vapor pressure (rVP) and flash point (FP) were observed between the single substances and the mixtures. The $EC_{50}$ of the mixture of EA and IPA was significantly lower than that of contained TOL and XYL. The mixture toxicity was related to the mixing ratio of MEK, TOL and XYL (MLR equation $EC_{50}=3.3081-2.5018{\times}TOL-3.2595{\times}XYL-12.6596{\times}MEK{\times}XYL$), as well as to BP, SG, VP and FP (MLR equation $EC_{50}=1.3424+6.2250{\times}FP-7.1198{\times}SG{\times}FP-0.03013{\times}rVP{\times}FP$). These results suggest that QPAR-based models could accurately predict the toxicity of polar and nonpolar mixtures used in rotogravure printing industries.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2008년도 한국컴퓨터종합학술대회논문집 Vol.35 No.1 (B)
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• pp.91-95
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• 2008

2005년 MND-AF v1.0의 제정으로 시작된 국방 아키텍처 활동은 2007년 범 정부 아키텍처 프레임워크와의 산출물 연계를 위한 v1.2 발표와 함께 새로운 전기를 맞고 있다. 본 논문에서는 국방 아키텍처 활동 소개와 국방 아키텍처 변화에 따른 국방기술품질원의 자체 아키텍팅 활동 정리 그리고 v1.2의 도입과 함께 최근 관심 사항이 되고 있는 ITA/EA 툴의 제품 동향과 도입 사업 추진 시의 평가기준 등을 제시한다.

• Journal of Pharmaceutical Investigation
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• 제24권4호
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• pp.273-279
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• 1994

The stability of three oximes, Hl-6 [(4-carbamoyl-2'[(hydroxyimino)-methyl]- 1,1'-oxydimethylenedi-(pyridinium chloride)], Hl-CN [(4 cyano-2'-[(hydroxyimino)-methyl] -1,1'-oxydimethylene-di-(pyridinium chloride)], and 2-PAM [pralidoxime chloride] in aqueous solutions was evaluated by HPLC assay. The rate of degradation is dependent on the pH as well as the temperature at which the solution is stored. The optimum pH for the stability of these oximes was pH 2 to 3. The degradation rate constant for 2-PAM ($k\;at\;70^{\circ}C$, $2.07{\times}10^{-4}/hr;\;E_a\;value$, 27.2 kcal/mol) was smaller than those for bis-pyridiniumoximes, Hl-6 ($k\;at\;70^{\circ}C$, $3.38{\times}10^{-3}/hr$) and Hl-CN ($k\;at\;70^{\circ}C$, $8.66{\times}10^{-3}/hr;\;Ea\;value$, 20.7 kcal/mol). In mechanistic analyses, it was found that Hl-CN was decomposed through not only the hydrolysis of nitrile group but also the cleavage of methylene ether bridge, in contrast to Hl-6 which was degraded mainly through the cleavage of methylene ether bridge.

• 한국군사과학기술학회지
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• 제22권2호
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• pp.215-223
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• 2019

A high temperature adhesive development which is crosslinked in low temperature is necessary for aerospace application because of thermal expansion mismatches of various substrates. For this purpose, we have designed and fabricated several formulations with high temperature epoxy resins, crosslinkers and additives considering various working conditions and high service temperature. As a result, some formulations showed higher adhesive strengths than Hysol EA 9394/C2 which is widely used for aerospace applications. We also have studied and summarized the mechanical properties of the best development adhesive in both room and high temperatures.

• 정보화연구
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• 제9권2호
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• pp.187-197
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• 2012

정보화 투자의 증가는 정보기술자원의 복잡성을 증대시켰으며, 이로 인해 중복투자 및 정보시스템 관리의 비효율성이 대두 되었다. 이에 정보기술 자원에 대한 효율적 도입과 관리를 위하여 EA(Enterprise Architecture) 사상이 발전하였다. 하지만, 데이터 영역에 대해서는 EA 사상이 발전한 이후에도 한동안 체계적인 지침의 제공이 미흡하였다. 따라서, 이제는 프로세스에 숨어있는 데이터를 도출, 관리하여 공공부문 각 기관 간 데이터의 공유성 및 재활용성을 높이기 위한 데이터 참조모형(DRM : Data Reference Model)의 활용이 필요하다. 이에 본 연구에서는 데이터 참조모형 중 가장 활용도가 높은 데이터 분류체계에 대한 개선의 필요성을 인식하고, 분류체계 재정립을 위한 방향성 및 연구 방법을 제시해 보려 한다.

• 디지털융복합연구
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• 제9권6호
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• pp.355-368
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• 2011

네트워크중심전(NCW: Network Centric Warfare) 환경 하에서 효과적인 전쟁수행을 위해서는 각종 시스템 간 데이터 공유가 필수적이며, 이를 위해서는 국방아키텍처(MND-EA) 고도화 및 국방 통합정보관리소 구축 등과 연계한 데이터 공동 활용을 위한 표준화와 통합관리 등이 필요하다. 본 연구의 목적은 현재 각 기관에서 주요 이슈로 등장하고 있는 데이터 공동 활용을 위한 마스터 데이터관리(Master Data Management: MDM)를 국방 분야에 도입하기 위해 기술수용모델을 활용하여 사용자의 이용의도에 영향을 미치는 요인들을 분석하고자 하였다. 또한 현재 총괄적인 기업 형태에 따라 보편적으로 적용되고 있는 가트너사(社)의 MDM 구현아키텍처를 대상으로 국방 업무환경과 특성을 고려한 선호아키텍처를 선정하고 이용의도에 미치는 영향을 분석함으로서 효과적인 국방 MDM(MND-MDM) 구축 방안을 제안하고자 한다. 자료조사는 국방정보화 시스템의 개발 및 유지보수와 자료를 관리하는 정 보화분야 담당자들과 국방정보시스템 개발 사업경험을 가진 주요 SI업체의 국방사업팀 담당자들을 대상으로 2011년 9월 19부터 10월 7일까지 3주간에 걸쳐 실시하였다.

• 공업화학
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• 제23권3호
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• pp.352-357
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• 2012

1,3,5-trinitro-1,3,5-triazacylohexane (RDX)와 octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)의 입자크기에 대한 열적 특성을 알아보기 위해서 DSC (Differential Scanning Calorimetry)와 TGA (Thermo-Gravimetric Analysis)를 사용하였다. 활성화 에너지와 빈도인자는 Kissinger 방법과 Vyazovkin 방법으로 계산하였다. DSC를 이용할 경우 RDX의 경우에는 고에너지 분자화약의 높은 분해열에 의하여 입자크기에 따른 활성화에너지의 경향성이 없었으나, TGA를 이용할 경우 입자크기가 클수록 활성화에너지가 커짐을 알 수 있었다. 그러나 HMX의 경우에는 DSC와 TGA의 방법 모두 입자 크기에 따라 활성화 에너지가 커지는 경향성을 보였다. 또한, Vyazovkin 방법을 이용하여 RDX와 HMX의 분해정도에 따른 활성화 에너지의 변화로 분해반응의 메커니즘을 이해할 수 있었다.

• 한국IT서비스학회지
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• 제5권1호
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• pp.111-128
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• 2006

It was on the rise importantly to provide the efficient management process of the organization for dealing with the change about information and business management quickly and consistently. It was suggested with the architectural model on information technology to provide it in theoretically. The Federal Government and budget organization of the USA used it on actual business and the terms of EA (Enterprise Architecture) and are raising the efficiency of management. NCA (National Computerization Agency) of Korea published the book - "The Research about establishing ITA (Information Technology Architecture) and appling the standards". After being applied the model on MOGAHA (Ministry of Government Administration and Home Affairs) and MIC(Minisstry of Information and Communication), the concrete case was made. MOMAF (Ministry of Maritime Affairs and Fisheries) drove the leading model. The report ascertained the basic contents of ITA and researched the case of USA, MOGAHA, MIC, and tried to analyze the contents of appling maritime and fisheries area. The report contained the definition of purpose through analyzing environment and establishing the vision and the principles based on them. The report also contained the contents of architecture based on the standard of NCA - "The Government Standard Meta Model version 2.0" - and researched the MOMAF's Reference model using Government Reference model. The report established the investment architecture and the process of information technology asset management. It ascertained the characteristic of maritime & fisheries area and the subject of developing the MOMAF's ITA sustainably.

• 한국군사과학기술학회지
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• 제18권2호
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• pp.131-138
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• 2015

Energetic monomers with new design concept were synthesized for energetic prepolymers. Novel energetic monomers consisted of ring-opening polymerizable oxirane and a molecular explosive moiety instead of small explosophores as energetic functional groups. According to the design concept, glycidyl dinitroazetidine (GDNAZ) and glycidyl nitroazetidinol(GNAZO) energetic monomers were synthesized, respectively, and characterized by NMR, EA and GC MS. Heat of formation and detonation performance were calculated by theoretical method to evaluate energy performance of these novel energetic monomers. The result revealed that GDANZ and GNAZO possessed high potential as new energetic monomers for synthesizing energetic prepolymers and binders in PBXs.