• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.168-169
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• 2013

In this study, the chemical resistance of polyurea resin waterproofing and anti-corrosion materials that is applied to the social infrastructure was analyzed. The result in this study will be utilizing as a basic data for establishing the quality standards which are able to judge the chemically resistant characteristic of polyurea resin waterproofing and anti-corrosion materials.

• Tribology and Lubricants
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• v.13 no.3
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• pp.1-9
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• 1997

인류가 지구상에 존재하기 이전에도 바다 속에는 오징어와 같이 자신의 힘만으로 분사 추진을 하여 움직이는 생물이 존재하였음에도 불구하고 인류는 이러한 반작용 원리를 이용한 항공용 가스터빈 엔진을 고안하는데 1900년 이상의 세월을 보내야 하였으며, 이 긴 세월 동안 많은 장치들이 고안되었다. 그러나, 실제로 이러한 원리를 사용한 현재와 같은 가스터빈 엔진의 개발은 1940년대 중반에야 가능하게 되었다. 이후 소형이면서 높은 추력을 발생시키기 위하여 많은 노력이 이루어져 왔으며, 이를 위하여 가스터빈 엔진의 주축 베어링, gearbox, seal 및 윤활 시스템 등은 더욱 큰 부담을 가질 수 밖에 없었다. 따라서, 이러한 어려움을 해결하고 보다 높은 추력을 발생시키는 가스터빈을 개발하는데 트라이볼로지의 역할이 중요하다고 할 수 있다. 가스터빈에서의 트라이볼로지의 적용 분야는 main-shift bearing, lubrication system, gearbox 및 seal등을 들 수 있으나, bearing과 lubrication을 중심으로 기술하고자 한다.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.32.4-33
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• 2016

활동성은하핵(AGN)의 거대 블랙홀 주변에 존재하는 플라스마 디스크의 구조나 물리적인 상태를 관측으로 직접 찾는 것은 AGN 중심부분에서의 제트 형성, 방출과정이나 에너지 수송과정을 조사하기 위해 중요한다. 지금껏 주로 센치미터파장 영역의 다주파 VLBI 관측으로 우리은하에서 가까운 AGN 속에 존재하는 10 pc 정도의 플라스마 디스크가 발견되어 있다만, AGN의 활동성을 정하고 있는 1 pc 이하의 스케일에서의 디스크 구조를 직접 관측한 결과는 아직 없다. 우리는 2015년8월부터 KVN 및 KVN과 일본 VERA로 구성되는 한일공동 VLBI 관측망(KaVA)을 이용해서 전파 은하 3C 84(z = 0.0176, 1 mas = 0.36 pc)의 밀리미터파장 모니터링을 진행하고 있다. KVN과 KaVA를 이용하면 1 pc 이하의 스케일로 3C 84의 중심구조를 고감도에서 분해할 수 있다. 이번 발표에서는 KVN 및 KaVA로 거의 동시에 실시한 관측결과를 중심으로 보고한다. 관측은 2016년2월22일(KaVA 43 GHz) 및 23일(KVN 86 GHz)에 실시되었다. 양 주파수의 이미지에서 종래의 센치미터 ~ 밀리미터파장 VLBI관측으로도 검출되어 있는 중심핵(C1) 및 남쪽에 약 3 mas 떨어져서 위치하는 로브(C3) 성분 뿐만 아니라 C1으로부터 북쪽에 약 2.5 mas 떨어져서 위치하는 새로운 성분(N1)을 검출하였다. N1의 검출 수준은 43, 86 GHz 모두 $6{\sigma}$이며, 양 주파수 사이에서 광학적으로 두꺼운 스펙트럼을 가지고 있다. 과거의 관측으로 측정된 C3의 겉보기 속도는 빛의 속도의 약 23%이며, 남북 로브의 구조와 운동의 대칭을 가정하면 N1이 도플러 분사출 효과 때문에 어두워지고 있는 가능성은 낮다. 따라서 C3에 대응하는 북쪽 N1로브로부터의 복사가 블랙홀 주변의 플라스마 디스크로 인해 저주파수에서 강한 흡수를 받고 있는 결과고 생각된다.

• Cross-Cultural Studies
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• v.53
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• pp.131-161
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• 2018

Emotional expressions are expressions that show the internal condition of mind or consciousness. Types of emotional expressions include vocabulary that describes emotion, the composition of sentences that expresses emotion such as an exclamatory sentence and rhetorical question, expressions of interjection, appellation, causative, passive, adverbs of attitude for an idea, and a style of writing. This study focuses on vocabulary that describes emotion and analyzes the aspect of translation when emotional expressions of 'Hu(怖)' is shown on "Kokoro". The aspect of translation was analyzed by three categories as follows; a part of speech, handling of subjects, and classification of meanings. As a result, the aspect of translation for expressions of Hu(怖)' showed that they were translated to vocabulary as they were suggested in the dictionary in some cases. However, they were not always translated as they were suggested in the dictionary. Vocabulary that described the emotion of 'Hu(怖)' in Japanese sentences were mostly translated to their corresponding parts of speech in Korean. Some adverbs needed to add 'verbs' when they were translated. Also, different vocabulary was added or used to maximize emotion. However, the correspondence of a part of speech in English was different from Korean. Examples of Japanese sentences that expressed 'Hu(怖)' by verbs were translated to expression of participles for passive verbs such as 'fear', 'dread', 'worry', and 'terrify' in many cases. Also, idioms were translated with focus on the function of sentences rather than the form of sentences. Examples, what was expressed in adverbs did not accompany verbs of 'Hu (怖)'. Instead, it was translated to the expression of participles for passive verbs and adjectives such as 'dread', 'worry', and 'terrify' in many cases. The main agents of emotion were shown in the first person and the third person in simple sentences. The translation on emotional expressions when a main agent was the first person showed that the fundamental word order of Japanese was translated as it was in Korean. However, adverbs of time and adverbs of degree tended to be added. Also, the first person as the main agent of emotion was positioned at the place of subject when it was translated in English. However, things or the cause of events were positioned at the place of subject in some cases to show the degree of 'Hu(怖)' which the main agent experienced. The expression of conjecture and supposition or a certain visual and auditory basis was added to translate the expression of emotion when the main agent of emotion was the third person. Simple sentences without a main agent of emotion showed that their subjects could be omitted even if they were essential components because they could be known through context in Korean. These omitted subjects were found and translated in English. Those subjects were not necessarily humans who were the main agents of emotion. They could be things or causes of events that specified the expression of emotion.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.120-127
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• 2021

Purpose: In this study, the effect of changes in the variables related to water droplets on the spray density on the floor in the analysis of the water mist fire protection system using FDS was analyzed. Method: When the spray of the water mist nozzle was analyzed in FDS, Particles Per Seconds, Particle Velocity, Size Distribution, and Spray Pattern Shape that can be set in relation to droplets were input to review the analyzed results. Result: In the analysis results, when the number of particles per second was set above a certain value, the spray density of the floor was similar. In the case of Particle Velocity, as the velocity decreases, the spray density of the central portion increases but decreases at a distance of 0.15m or more. From the analysis of the change in the size distribution function, it was found that an increase in the 𝛾 value increases the spray density of the central part, but the value at a remote location decreases. Compared to the result of applying the Gaussian distribution, the median value decreases dramatically when the uniform distribution is applied, but the value at the adjacent position increases. Conclusion: Variables related to the droplet properties of the FDS affect the spray density of the floor. Therefore, in order to increase the reliability of results before performing analyses such as fire suppression or cooling, a sufficient review of input variables is required.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.4
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• pp.61-68
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• 2015

Reactive sprays of two propellant combinations(GOx/kerosene and $GN_2O$/ethanol) were observed and compared with each other as a basic research of visualizing supercritical combustion. A shadowgraph imaging method was used to visualize the reactive sprays, and shadowgraph images were converted to density gradient magnitude images to analyse the structure of reactive sprays. The gas-liquid interface of GOx/kerosene spray showed rougher boundary and steeper density gradient near the injector face than the $N_2O$/ethanol at similar combustion chamber pressure. Spray core length was calculated from averaged density gradient magnitude images and it was revealed that spray core length of GOx/kerosene was shorter than that of $GN_2O$/ethanol, although momentum flux ratio of GOx/kerosene propellant combination was lower.

• Fire Science and Engineering
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• v.33 no.1
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• pp.92-98
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• 2019

To determine if water-jet nozzle moves and water jetting are effective according to the location of the fire, this study examined the automatic fire-tracking water cannon system and aan indoor hydrant system, such as water jet centered directivity, water jet range maintainability and water jet shape uniformity. First, an examination to find the center of fire accurately from this system design showed that the water jet centered test was accurate. Second, the water jet range test results showed that when water is jetted at the maximum water jet radius, the water jet shows an inaccurate result but within the allowable tolerance range. Finally, the water-jet shape test result confirmed that there are no problems in setting the block from the algorithm design.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.4
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• pp.302-307
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• 2001

The underwater background noise measured in Geoje and Tongyoung diving fishing ground from May to December, 2000 and analyzed to get optimum carrier frequency and transmitter power level for underwater wireless telephone design. The results obtained are summarized as follows: 1. At the Geoje and Tongyoung diving fishing ground, the lowest ambient noise band was 25~30kHz with 57dB and 52dB re 1$\mu$Pa, respectively. 2. At the Geoje and Tongyoung diving fishing ground, the lowest noise band during fishing activity was 67dB and 62dB re 1$\mu$Pa, respectively. 3. At the Geoje diving fishing ground, the noise of water jetter which is a digging machine for subbottom shells was 102dB re 1$\mu$Pa. 4. Considering the design parameters of underwater wireless telephone, it is found that the optimum carrier frequency band is around 30kHz and the transmitter source level should be at least 131dB re 1$\mu$Pa for 500m range telephone.

• Cross-Cultural Studies
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• v.51
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• pp.329-356
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• 2018

Types of emotional expressions are comprised of vocabulary that describes emotion and composition of sentences to express emotion such as an exclamatory sentence and a rhetorical question, expressions of interjection, adverbs of attitude for an idea, and a style of writing. This study is focused on vocabulary that describes emotion and analyzes the aspect of translation when emotional expression of 'Kyo(驚)' is shown in "Kokoro". As a result, the aspect of translation for expression of 'Kyo(驚)' showed that it was translated to vocabulary as suggested in the dictionary in some cases. However, it was not always translated as suggested in the dictionary. Vocabulary that describes the emotion of 'Kyo(驚)' in Japanese sentences is mostly translated to corresponding parts of speech in Korean. Some adverbs needed to add 'verbs' when they were translated. Different vocabulary was added or used to maximize emotion. However, the corresponding part of speech in English was different from Korean. Examples of Japanese sentences expressing 'Kyo(驚)' by verbs were translated to expression of participles for passive verbs such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Idioms were also translated with focus on the function of sentences rather than the form of sentences. Those expressed in adverbs did not accompany verbs of 'Kyo(驚)'. They were translated to expression of participles for passive verbs and adjectives such as 'surprise' 'astonish' 'amaze' 'shock' 'frighten' 'stun' in many cases. Main agents of emotion were showat the first person and the third person in simple sentences. Translation of emotional expressions when a main agent was the first person showed that the fundamental word order of Japanese was translated as in Korean. However, adverbs of time and adverbs of degree were ended to be added. The first person as the main agent of emotion was positioned at the place of subject when it was translated in English. However, things or causes of events were positioned at the place of subject in some cases to show the degree of 'Kyo(驚)' which the main agent experienced. The expression of conjecture and supposition or a certain visual and auditory basis was added to translate the expression of emotion when the main agent of emotion was the third person. Simple sentences without the main agent of emotion showed that their subjects could be omitted even if they were essential components because they could be known through context in Korean. These omitted subjects were found and translated in English. Those subjects were not necessarily human who was the main agent of emotion. They could be things or causes of events that specified the expression of emotion.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.139-143
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• 2005

Combustion Test Facility for Liquid Rocket Engine using kerosene and liquid oxygen has been developed for the purpose of cooling and performance study. Test engine of thrust 0.5 KN(design thrust) is tested to confirm the normal operation. Therefore, water-cooled firing tests using kerosene engine with injectors of fuel-centered coaxial type are conducted. With the viewpoint of characteristic velocity, and specific impulse at sea level, and chamber pressure on OF mixture ratio are analyzed.