• Structural Engineering and Mechanics
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• 제77권6호
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• pp.705-720
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• 2021

Reinforced concrete (RC) columns are the primary type of vertical support used in building structures that sustain vertical loads. However, their strength may be insufficient due to fire, earthquake or volatile environments. The load demand may be increased due to new functional usages of the structure. The deformability of concrete columns can be greatly reduced under high axial load conditions. In response, a novel steel encasement that distinguishes from the traditional steel jacketing that is assembled by welding or bolt is developed. This novel strengthening method features easy installation and quick strengthening because direct fastening is used to connect the four steel plates surrounding the column. This new connection method is usually used to quickly and stably connect two steel components by driving high strength fastener into the steel components. The connections together with the steel plates behave like transverse reinforcement, which can provide passive confinement to the concrete. The confined column along with the steel plates resist the axial load. By this way, the axial load capacity and deformability of the column can be enhanced. Eight columns are tested to examine the reliability and effectiveness of the proposed method. The effects of the vertical spacing between adjacent connections, thickness of the steel plate and number of fasteners in each connection are studied to identify the critical parameters which affect the load bearing performance and deformation behavior. Lastly, a theoretical model is proposed for predicting the axial load capacity of the strengthened RC columns.

• 대한건축학회논문집:계획계
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• 제34권4호
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• pp.133-140
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• 2018

This study is change of the street space of the port city of Yokohama and the transformation process of the canal. modern port city Yokohama is a region that was responsible for the development of East-West maritime transport routes in Japan in the 17th century and the inland transportation through fishing villages and ports. it has also grown rapidly as a regional port and new port. In particular, through the revitalization of trade between foreign settlements and Japanese residents in the port area, the existing fishing area became a modern port city space. Yokohama went through the following process and grew into a modern port city. The construction of the port harbor and the maintenance of existing logistics functions, the formation of the central horizontal axis through maintenance of the fishing village, the construction of the logistics movement route to the inland area through the construction of the canal, the expansion of the horizon for fire prevention and fire restoration, The formation of a new settlement space according to the movement, the transformation of the existing religious axis by the combination of the elaboration and the introduction of modern transportation, and the spatial connection between the inland cities.

• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.63-66
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• 2017

All passenger ships aboard more than 36 passengers are to be able to easily find escape routes when the escape way by fire with flame spread were onboard vessel (incl. Ferry, Passenger, Ro-pax, Inland Ferry) It should be impossible by ordinary emergency lights. The international Maritime Organization (IMO) gives special requirement for luminescent evaluation onboard test procedure and applicable location of low location lighting. In order to maintain the residual light source for a certain time in the low location lighting with a strip-shaped light source, the light source material must be sufficiently exposed to the light due to the proper placement of the escape route. The lighting arrangement influence how maintain low location lighting strip luminescent which measured onboard in connection with what elements are mainly sustain luminescent.

• 대한공간정보학회지
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• 제22권4호
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• pp.63-69
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• 2014

건설 기술의 발달과 도시지역의 인구증가로 인하여 생활공간은 지상과 지하로 확대되었고 도시 교통난이 증가함에 따라 대중교통수단으로서 지하철건설이 확대 되었다. 이로 인하여 지하상가가 발달하였고 지하도시공간은 생활공간과 문화공간의 중심이 되었다. 그러나 지하도시공간은 지상공간과는 달리 화재가 발생 했을 때 조도가 낮아 연기로 인한 시야확보의 어려움, 순간적인 판단오류로 인한 방위감 상실, 열기의 급격한 확산과 외기 획득 제한성으로 인한 산소 결핍 등으로 막대한 인명피해와 재산손실을 초래한다. 이에 본 연구에서는 기존의 지하상가의 주소체계에 대하여 분석하고 도로명주소와 연계하여 직선의 지하상가와 원형의 지하상가에 대한 주소체계를 제시하고자 한다. 또한 지하상가 주소체계표준화를 통하여 화재 발생 시 지하상가 내부에 있는 시민들이 주소만으로 자신의 위치를 알고 대피할 수 있으며, 소방서에서는 정확한 위치 파악이 가능할 것이라 판단된다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권1호
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• pp.99-104
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• 2014

본 논문에서는 탄화수소화재 조건에 따른 방화 댐퍼의 내화성능 평가에 대한 선행논문 실험체 -1(126 mm, $136^{\circ}C$)에 대하여 H-120 등급 방열성 확보가 가능한 최적의 코밍 방열 조건을 도출 하고자 노출면 코밍 방열 두께와 비 노출면 코밍 방열 길이 변화를 변수로 하여 내화실험을 수행 하였다. 내화실험 결과 실험체-2(88 mm, $171^{\circ}C$)는 H-120 방열성 허용기준을 만족하였으나, 실험체-3(50 mm, $185^{\circ}C$)은 110분에 방열성능 허용기준을 초과하는 것으로 나타나 실험체-2의 방열 조건이 실험체-1로부터 경량화가 가능한 최적의 방열 조건으로 확인 되었으며, 온도상승에 대한 비교결과 노출면 코밍 방열두께가 감소될 경우 방열재 표면온도는 격벽을 통한 전도열에 의한 영향 크며, 코밍 표면온도는 블레이드와 노출면 코밍으로부터 방사되는 복사열에 의한 영향이 큰 것으로 판단된다.

• 한국산학기술학회논문지
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• 제21권3호
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• pp.585-593
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• 2020

현재까지 총 29건의 전기저장장치의 화재가 발생되었는데, 이 중 22건이 신재생에너지 연계용이며, 완전충전 이후, 운전대기 상태인 휴지기간 동안에 계절과 무관하게 화재사고가 발생되었다. 이것은 병렬로 연결된 셀들의 SOC 상태가 서로 다른 경우, 의도하지 않게 SOC가 높은 셀에서 낮은 셀로 전류가 이동하는 셀프에너지 밸런싱 현상으로, 일부 셀이 과충전되어 열폭주로 인한 화재의 원인으로 평가되고 있다. 따라서, 본 논문에서는 전기저장장치의 셀프에너지 밸런싱을 방지하는 새로운 BMS의 회로구성과 운용 알고리즘 그리고 SOC 평가알고리즘을 제안한다. 제안한 알고리즘과 구현한 BMS를 바탕으로 리튬이온전지의 열화 특성과 열화 및 정상 셀 간의 셀프에너지 밸런싱 특성을 분석한 결과, 정상 셀 대비 열화 셀의 방전 용량 비율은 91.75[%]이며, 열화율이 8.25[%]임을 알 수 있었고, SOC가 높은 정상 셀에서 SOC 낮은 열화 셀로 전류가 이동하는 셀프에너지 밸런싱 현상이 발생함을 확인하였다. 또한, 셀프에너지 밸런싱 전류가 과도하게 높아지는 경우, BMS가 확실하게 셀들의 병렬연결을 분리하여, 리튬이온전지의 안전성을 향상시킬 수 있어, 본 논문에서 제안한 BMS의 유용성을 확인하였다.

• 한국안전학회지
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• 제29권2호
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• pp.12-17
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• 2014

This paper is aimed to analyze the characteristics of simultaneous voltage, current and temperature signals for poor connection on electrical connector. In order to attain this purpose, detected were the current and voltage signals on electric wire with series arc, named arc signals, and also monitored were the changes of RMS, instantaneous value of waveform in time domain and temperature value with video. Two states are made normal state over $5kgf{\cdot}cm$ and poor connections state below $0.5kgf{\cdot}cm$ by screw gage. In the voltage signal case, the voltage drop was increased with which the current was increased. In the current signal case, poor connections at the time interval 1~4A all showed "shoulder", as distinct difference from the normal state shown waveform pattern. In the temperature signal case, poor connections are twice at 1A and five times at 4A in the normal state. The temperature continues insulation of electrical wiring and connector can be carbonized. The results of this study will be effectively used in developing the preventive devices and system for electric fire by poor connections.

• 한국위험물학회지
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• 제2권1호
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• pp.31-37
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• 2014

Since the unprecedented hydrogen fluoride leak accident in 2012, there has been growing demand for customized technical information for rapid response and chemical accident management agencies including the Ministry of Environment, the National Emergency Management Agency, and the National Police Agency need more information on chemicals and accident management. In this regard, this study aims to provide reliable technical data and guidelines to initial response agencies, similar to accident management technical reports of the US and Canada. In this study, we conducted a questionnaire survey and interviews on initial response agencies like fire stations, police stations, and local governments to identify new information items for appropriate initial response and improvements of current guidelines. We also collected and reviewed the Canada's TIPS, US EPA's hydrogen fluoride documents, domestic and foreign literature on applicability tests of control chemicals, and interview data, and then produced items to be listed in the technical guidelines. In addition, to establish database of on-site technical information, we carried out applicability tests for accident control data including ① emergency shut down devide, safety guard, shut down valve, ground connection, dyke, transfer pipe, scrubber, and sensor; ② literature and field survey on distribution type and transportation/storage characteristics (container identification, valve, ground connection, etc.); ③ classification and identification of storage/transportation facilities and emergency management methodslike leak prevention, chemicals control, and cutoff or bypass of rain drainage; ④ domestic/foreign analysis methods and environmental standards including portable detection methods, test standards, and exposure limits; and ⑤ comparison/evaluation of neutralization efficiency of control chemicals on toxic substances.

• 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.

• 동의생리병리학회지
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• 제17권4호
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• pp.861-878
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• 2003

In the ancient time wind is considered as the life . soul and the human's breath which represents essence of universal creation and the absolute power and also the messenger of the god or god's state. Greek's 'pneuma' , India's 'Brahman' and the Old Testament's 'ruach' are used to signify the wind. Also Wind(風) in traditional culture, it is related to 玄妙之道 of 花郞, the flower of youth in Shilla dynasty and sexual intercourse in shaman's dream which can be thought as Freud's libido. In this aspect we can see the connection between the wind and the libido which can be meaning of sexual desire. Ancient Chinese wrote word ‘風’ as phoenix, the god's bird, the phoenix in inscriptions on bones and tortoise carapace(甲骨文) because one can feel the wind but can’t see it. The word Ki(氣) origins from 風 therefore 風 is 氣's fundamental notion. The wind can be understood by ki which travels around the world to create all nature. And the Wind is associated with 風化, 玄鳥, 八僧舞, which are related with reproduction. In the book of change (周易) the 震巽卦 ; 雷風 come under wind which means the function of ki and also menas the 精(essence of life) of 恒久(eternity) means the reprodution ; that performs succession of life. In the Oriental Medicine 氣 is a phenomenon that appears by movement of Ki by 相火(Ministerial fire). 相火 is core of the succession of life which means preservation of descendants; therefore 風 has very similar concept with sexual desire. 風 is the beginning ki of universe and in human body aspect 風 belong to the Liver Meridian. If 風 makes movement then the Pericardium Meridian of Hand Kwolum responds and the genital organs which belongs to Liver Meridian of Leg Kwolum reproductive function by contraction and expansion. Generally 風 understood as movement and origination and this is recognized as meaning of 氣. Therefore as studied above the present writer believe m. participates closely to reproductive function.