• 한국항공우주학회지
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• 제40권1호
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• pp.61-68
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• 2012

항공기용 블랙박스의 자료보호모듈(CPM)은 항공사고와 같은 극한 환경후에도 저장된 정보(비행데이터 및 조종석음성)를 안전하게 보호하는 것을 목적으로 한다. 본 연구에서는 CPM에 대하여 관통저항력과 고온 및 저온내화의 극한환경시험에 대한 구조 및 방열측면의 해석 및 시험을 통한 검증에 대하여 기술하였다. 특히 관통저항력해석에서는 하우징의 두께에 따른 영향성을 LS-DYNA를 이용하여 검토하였으며, 고온 및 저온내화해석에서는 상변화물질과 단열재의 체적비에 따른 영향성을 Icepak을 이용하여 수행하였다. 또한 실험을 통하여 CPM의 구조 및 열적 신뢰성을 검증하였다.

• 한국대기환경학회지
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• 제27권6호
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• pp.650-662
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• 2011

The statistical tools such as empirical orthogonal function (EOF), and singular value decomposition (SVD) have been applied to analyze the characteristic of air pollutant over southeast Asia as well as to evaluate Zimeke's tropospheric column ozone (ZTO) determined by tropospheric residual method. In this study, we found that the EOF and SVD analyses are useful methods to extract the most significant temporal and spatial pattern from enormous amounts of satellite data. The EOF analyses with OMI $NO_2$ and OMI HCHO over southeast Asia revealed that the spatial pattern showed high correlation with fire count (r=0.8) and the EOF analysis of CO (r=0.7). This suggests that biomass burning influences a major seasonal variability on $NO_2$ and HCHO over this region. The EOF analysis of ZTO has indicated that the location of maximum ZTO was considerably shifted westward from the location of maximum of fire count and maximum month of ZTO occurred a month later than maximum month (March) of $NO_2$, HCHO and CO. For further analyses, we have performed the SVD analyses between ZTO and ozone precursor to examine their correlation and to check temporal and spatial consistency between two variables. The spatial pattern of ZTO showed latitudinal gradient that could result from latitudinal gradient of stratospheric ozone and temporal maximum of ZTO in March appears to be associated with stratospheric ozone variability that shows maximum in March. These results suggest that there are some sources of error in the tropospheric residual method associated with cloud height error, low efficiency of tropospheric ozone, and low accuracy in lower stratospheric ozone.

• 품질경영학회지
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• 제48권1호
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• pp.13-27
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• 2020

Purpose: The purpose of this study is to present a recoil measurement and analysis of K2 rifle for the development of a virtual reality marksmanship training in the Republic of Korea Army. Methods: For the recoil measurement, a test-bed is built by a barrel that has exact dimensions of K2 rifle and three piezoelectric pressure sensors mounted on the barrel. Data of over 200 rounds of 5.56mm M193 and K100 bullets are collected and analyzed from live fire experiments. For the recoil analysis, both the free recoil method and the gas exhaust aftereffect method are used to calculate a recoil velocity, momentum and kinetic energy of K2 rifle by applying the law of conservation of momentum. In addition, a new method is proposed that uses the third law of motion and the chamber pressure model for the recoil measurement Results: The results show how different between the previous and proposed methods with respect to M193 and K100 bullets of K2 rifle. In M193, the free recoil method demonstrates 1.113, 4.197, and 2.335, the gas exhaust aftereffect method computes 1.698, 6.407, and 5.441, and the proposed method calculates 0.990, 3.734, and 1.848 in recoil velocity, momentum and kinetic energy, respectively. In K100, the free recoil method demonstrates 1.190, 4.487, and 2.669, the gas exhaust aftereffect method computes 1.776, 6.699, and 5.949, and the proposed method calculates 1.060, 3.998, and 2.119 in recoil velocity, momentum and kinetic energy, respectively. Conclusion: This study implements live fire experiments to provide recoil velocity, momentum, and kinetic energy of K2 rifle using both M193 and K100 bullets. For the development of the army virtual reality marksmanship, the results in this paper would be useful to design and produce a gun and/or a rifle of virtual reality.

• 한국안전학회지
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• 제26권4호
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• pp.41-46
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• 2011

The purpose of this paper is to analyze the causes of accidents related to the 3 phase 170 kV gas insulated switchgear of a power system collected from accident sites to secure data for the prevention of similar accidents and provide important points of view regarding diagnosis for the prevention of accidents involving gas insulated switchgears. The analysis results of the causes of accidents involving gas insulated switchgears showed deformation of the manipulation lever installed at the S-phase, disconnection of the insulation rod connection, melting of the upper conductor, a damaged tulip, damage to the lower spacer and the spacer at the breaker, etc. It is believed from this result that the potential for accidents has expanded due to accumulated energy as a result of repeated deterioration. The carbonization depth of a GIS was formed near the screw (T2, T3) used to secure the lower pole of the S-phase tulip. It is not known what has caused the screws to be extruded and melted. However, it is thought that an unbalanced electromagnetic force, micro-discharge, surface discharge, etc., have occurred at that point. In addition, even though 16 years have passed since its installation, there was no installation defect, act of arson, accidental fire, etc. General periodical inspection and diagnosis failed to find the factors causing the accidents. As a system contained in a closed metal container, it has a high risk factor. Therefore, it is necessary to design, install and operate a GIS in accordance with the standard operational procedure (SOP). In addition, it is necessary to apply conversion technology for periodical SF6 gas analysis and precision safety diagnosis. It is expected that tracking and managing these changes in characteristics by recording the results on the history card will provide a significant accident prevention effect.

• 한국정보통신학회논문지
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• 제22권11호
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• pp.1474-1480
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• 2018

고층 빌딩에서 화재가 발생하는 경우 복잡한 구조로 인해 다양한 대피 통로가 존재하며 각 대피 통로의 안전성 여부를 파악하는 것이 어렵다. 고층 빌딩 화재 시 거주자들에게 신속히 탈출 경로를 제공하는 것이 필요하며 이를 위해서 대피 통로의 안정성 여부를 파악할 필요가 있다. 본 논문에서는 대피 통로의 안정성 여부 파악을 위해 영상을 분석하여 화재 시 발생하는 연기로 인한 대피 통로의 가시도를 측정하는 방법을 제안한다. 입력 영상에서 연기를 검출한 후 검출된 연기의 밀도를 알 수 있다면 가시도를 쉽게 측정할 수 있지만, 연기 검출이나 연기 밀도 측정에 관한 적절한 방법이 없어 이러한 접근법을 사용하기는 어렵다. 본 논문에서는 입력 영상에서 배경 영상을 추출하고 이를 학습 데이터로 하여 주성분 분석 학습을 한다. 이후 입력으로 주어지는 영상에서 배경 영상과 연기 영상을 추출하고 학습된 주성분 분석을 적용하여 새로운 특징 공간으로 사상한 후 변화량을 계산하여 연기로 인한 가시도를 측정한다.

• 문화기술의 융합
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• 제5권1호
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• pp.185-191
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• 2019

스마트폰의 이용은 현대인의 생활에 편리함과 효율성을 증진시키나, 스마트폰이 없으면 일상생활을 하기 어려운 사용현상도 나타남으로써 개인의 정신건강을 위협한다. 특히 재난 및 화재에 노출되는 근무환경으로 인해 직무스트레스가 매우 높은 소방공무원의 스마트폰 사용현상은 이들의 개인적 안녕 및 직무수행에 매우 부정적인 영향을 미친다고 추측되어진다. 따라서 소방공무원들의 스마트폰 사용과 스트레스간의 관계에 대한 분석은 이들의 스트레스관리에 대한 문제점들을 살펴본다는 점에서 의미가 있다. 이 연구는 소방공무원의 스마트폰 사용 그리고 스트레스간의 관계 및 영향을 분석한다. 연구대상자는 총 230명이고 통계방법은 SPSS 20.2에 의한 집단별 분석(t-test와 ANOVA) 그리고 위계적 회귀분석을 사용하였다. 주요연구결과로는 소방공무원의 가구형태와 월수입이 스트레스에 유의미한 영향을 미쳤으며, 스마트폰 사용 하위요인 중 금단경험이 통계적으로 유의미한 영향을 미쳤다. 연구결과는 소방공무원의 스마트폰 사용에 대한 실증적 자료로 제공될 것이다.

• 한국컴퓨터정보학회논문지
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• 제14권5호
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• pp.167-174
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• 2009

데이터베이스의 의미는 '논리적으로 연관된 레코드나 파일의 모임'으로 방대한 자료를 효율적으로 관리하기 위해 많은 양의 자료를 처리하는 곳에서 널리 사용되고 있다. 이러한 데이터베이스를 생성하고, 관리하고, 사용자의 요구(Request)에 따라 응답(Response)을 보내는 프로그램들을 데이터베이스 관리시스템이라고 부른다. 본 연구에서는, 이와 같이 중요한 데이터베이스 소프트웨어 제품의 품질 수준을 파악할 수 있는 지표를 도출하여 지표산식을 정의하였다. 또한, 지표의 결과를 산출하기 위해 필요한 수집항목을 선정하며 수집과 분석을 통해 실질적으로 어떤 결함유형들이 주로 발생하고 있는지를 확인하였으며 데이터베이스 소프트웨어에 대한 시험 평가모델을 개발하여 시험 사례를 분석하였다.

• 동의신경정신과학회지
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• 제28권4호
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• pp.349-358
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• 2017

Objectives: To analyze whether a concept similar to Korean 'Hwabyung' exists in China. We investigated the status of clinical studies conducted in China for relevant diseases and trends of the traditional Chinese medicinal (TCM) treatment adopted in clinical studies. Methods: To explore the concept of a condition similar to Korean Hwabyung in China, we searched for the existence of concept and pattern that were parallel or similar to those of Hwabyung in TCM text-books and diagnostic guidelines. We searched and analyzed clinical studies of TCM treatment for depression syndrome similar to Hwabyung from CNKI using terms 'depression' and 'qi stagnation transforming into fire'. Using extracted data, characteristics of clinical research, herbal medicine, and acupuncture treatment used in the clinical research and their effects were systematically reviewed. Results: Symptoms of 'qi stagnation transforming into fire' were most similar to those of Hwabyung. Nine articles were selected from a total 258 articles. Most of them used DSM-IV or CCMD-3 for depression diagnosis. They applied 'diagnostic and efficacy guidelines for TCM diseases and syndromes' for pattern diagnosis of 'qi stagnation transforming into fire'. Danzhixiaoyao-san and Jiaweixiaoyao-san were found to be effective when they were used alone or in combination with antidepressants. Acupuncture treatment also showed remarkable effect on LR3, HT7, LI4, PC6, GV20 when it was used alone or in combination with antidepressants. However, careful interpretation is required because a small number of studies are included.Conclusions: 'Qi stagnation transforming into fire' seemed to have symptoms similar to Hwabyung. However, further research is needed to determine its diseases and pattern types compared to Hwabyung. According to included studies of 'depression with Qi stagnation transforming into fire', herbal medicine and acupuncture treatment tended to be effective in relieving depressive symptoms. However, more discussion is required for future application of herbal medicine and acupuncture for treating Hwabyung.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1171-1176
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• 2011

According to the 'Rules on the Safety Standard of Railroad Facilities', the 'Detailed Safety Standards of Railroad Facilities' and 'the Standards for Railroad Design' unified of MLTM(Ministry of Land, Transport and Maritime Affairs), the risk analysis on the application of fire safety facilities should be quantitatively performed to ensure the safety in tunnels over 1km long. This paper aims at proposal of basic data for the safety facilities' planning with reasonable and appropriate scale through case studies on different model tunnels.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.718-723
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• 2007

A three dimensional multibody modeling of a launcher system was developed and dynamic characteristics of the system was carried out. All the components were modeled as rigid bodies, All the components of system, ie; chassis, turret, cage and suspension parts, are modeled as rigid. The force interaction between the ground and tire was modeled as a point contact model. The factors were selected as cause and effect diagram of the MINITAB. To see effect of the stiffness, damping, mass at the launcher system, several cases of suspension parameters were compared and optimal values were selected. The stiffness and the damping coefficient were selected as design variables to minimize the required time for the next fire. The dynamic simulation was carried out using the ADAMS, and the MINITAB was employed for data analysis.