• Title/Summary/Keyword: Air Movement

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Analysis of Atmospheric Sulfur Compounds in Cheju (제주지역을 중심으로 한 대기 중 황화합물의 관측)

  • Hilton, Swan;Yang, Gyu-Seung;Kim, Ji-Young;Shon, Zang-Ho;Lee, Gang-woong;Kang, Chang-Hee;Kim, Ki-Hyun
    • Journal of the Korean earth science society
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    • v.23 no.5
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    • pp.416-423
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    • 2002
  • The concentrations of dimethylsulfide (DMS) and carbon disulfide (CS$_2$) were measured concurrently with relevant environmental parameters at Kosan, Cheju during Apr 2001. Results of our analysis indicate that the combined temporal variations of both DMS and CS$_2$ record three distinctible patterns that are separable from each other. For instance, DMS behaved very similarly to CS$_2$ during the 1st (5${\sim}$18 Apr) and 3rd period (23${\sim}$26 Apr). The pronouncingly high concentration of CS$_2$ was maintained during the first period, but DMS values peaked mostly during the third period. It was furthermore striking to find that changes in DMS levels occurred in an opposite direction relative to CS$_2$ during the 2nd period. Although most of these variabilities appear to be associated with the interaction of source/sink processes and the air parcel movement, certain aspects of their behavior are found to be highly complicated enough to account for.

Effects of Some Soil Conditioners on Soil Physical Properties and Lettuce Growth (토양구조개선제(土壤構造改善劑) 처리(處理)가 토양물리성(土壤物理性)과 상추생육(生育)에 미치는 영향(影響))

  • Ryu, In-Soo;Han, Jeung-Lim;Jo, In-Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.28 no.3
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    • pp.249-255
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    • 1995
  • This study was conducted to investigate the effects of some soil conditioners, such as polyacrylamide(PAM), polyvinylalcohol(PVA) and Bitumen emulsion, on aggregate formation and stability, wetting angle, sorptivity and penetrability of the soil with different textures : sand, sandy loam, loam and clay loam. A pot experiment was carried out to find out the effect of treatment on the germination and growth of lettuce with three textures : sand, sandy loam and silt loam. Soil aggregates larger than 2mm in untreated soils at dry condition were naught in sand, 45% in sandy loam, 80% in loam and 90% in clay loam. Treatments of soil conditioners tended to increase the occurrence of soil aggregate larger than 2mm, which were 20~25% in sand, 55~75% sandy loam, but not affected greatly aggragate occurence in loam and clay loam. The aggregate instability was decreased by the soil conditioner treatment. The wetting angles of the soils were greatly changed by hydrophobic of Bitumen, but those were changed slightly by PVA and PAM application. The sorptivity and penetrability data indicated that the effects of different materials on these parameters differed depending upon soil texture. Application of PVA and PAM were no effect exceptive in sand. Application of Bitumen revealed that water movement was not showed in all soils. The germination rate, root weight and top plant weight of lettuce were increased in all soils by PAM treatment as compared to untreated soils. Particularly the greater effect was occurred in sand soil than in sandy loam and silt loam. PAM increased greatly the moisture content and air phase of soils.

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Smoke Control Experiment of a Very Deep Underground Station Where Platform Screens Doors are Installed - Analysis on Smoke Control Performance by Fans equipped in Tunnel (스크린도어가 설치된 대심도 지하역사의 제연 실험 - 터널 송풍기에 의한 제연의 효과 분석)

  • Park, Won-Hee;Kim, Chang-Yong;Cho, Youngmin
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.9
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    • pp.721-736
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    • 2019
  • In this paper, the behavior of the fire smoke due to the operation of the ventilation systems when the fire occurred in the underground station (6 basement floors) and the tunnel at the great depth was measured. Fire smoke was generated by using a smoke generator which realized heat buoyancy effect by using hot air blower. The two locations of the fire were selected on the platform and on the platform of the tunnel located outside the screen door. A ventilation mode is generally used in which smoke is exhausted through a vent hole provided in a platform when a platform fire occurs. The tests were performed by operating the exhaust through the ventilation holes of the tunnel part located at both ends of the platform. The smoke density and the wind speed/velocity were measured at various positions, and the videos were taken to analyze the movement and smoke of the smoke. In both cases for fire inside the platform and in the railway tunnel, due to the ventilation mode operation of the fan for the platform and the exhaust of the fans in the tunnel smoke were well exhausted and the smoke propagation to the area near the smoke zone was suppressed. The smoke-control mode, which is applied to both fans for the platform and fans for in the tunnel at both ends of the platform, can provide a safer evacuation environment to the passengers from the fire smoke when the platform fire or fire train stops.

A Study on the Fine Dust Removal Equipment of Pressurized Water type for the Removal of Exhaust Gas Fine Dust and Volatile Organic Compounds from the Non-industrial combustion plant (비산업 연소 사업장 배출 가스상 미세먼지와 휘발성 유기 화합물 제거를 위한 가압수식 미세먼지 제거 장치 연구)

  • Youn, Jae-Seo;Kim, Sang-Min;Lee, Ye-Ji;Noh, Seong-Yeo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.506-512
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    • 2018
  • The fine dust generated in the home and restaurant business occupies a low ratio of about 4% of the total fine dust emissions. However, at the foodservice business, the rate of change of the pollutant concentration is very high, so that the temporary fine dust concentration can be measured up to 60 times. The pollutants generated from non-industrial combustion plants consist of particulate fine dust and gaseous organic compounds. To remove these pollutants, cleaning dust collection system, which is an effective system for simultaneous removal of gaseous and particulate matter, is applied. This is a method of increasing the probability of diffusion capture of the Brownian motion by pressurized liquid injection method using the atomizing nozzle. The dust removal efficiency of the fine dust collecting system was analyzed by nozzle spraying air pressure condition and angle using the manufactured fine dust removing system. As a result, it was confirmed that the efficiency of removal of fine dust and gaseous organic compounds was more than 90%. The developed system is expected to be highly usable in the future because it can remove particulate dust from the existing plant hood system without any installation cost.

A Survey on Awareness and Availability on Items of 2018 Assistive Devices Distribution Program for the Disabled in the Occupational Therapists (2018년도 장애인 보조기기 교부사업 품목에 대한 작업치료사의 인식도와 활용도 조사)

  • Kim, Jeong-Eun;Park, Je-Min;Bae, Su-Yeong;Jung, Nam-hae
    • Korean Journal of Occupational Therapy
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    • v.26 no.4
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    • pp.85-95
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    • 2018
  • Objective : The purpose of this study was to investigate the awareness and availability on items of 2018 assistive devices distribution program for the disabled in the occupational therapists. Methods : A total of 132 occupational therapists participated in the survey from May 1 to May 31. Results : 96.2% of the occupational therapists responded that assistive device is helpful in lives of the disabled people. Especially, they responded that assistive device is the most helpful in 'movement and mobility'. Awareness on an angle spoon/fork with built-up handle and universal cuff was the highest, while a visual signaling indicator was the lowest. Availability on an air cushion was the highest, while a visual signaling indicator and a voice guidance system were the lowest. 67.4% responded that 'sometimes' they use the assistive device and 77.3% responded they will utilize the assistive device. To improve awareness and availability, 43.2% needed financial support, 32.6% needed to add insurance bill and 22.7% needed related education. Conclusion : In the future, this result will be available as a basic data for the education about assistive device for the occupational therapists.

Development of Robot Platform for Autonomous Underwater Intervention (수중 자율작업용 로봇 플랫폼 개발)

  • Yeu, Taekyeong;Choi, Hyun Taek;Lee, Yoongeon;Chae, Junbo;Lee, Yeongjun;Kim, Seong Soon;Park, Sanghyun;Lee, Tae Hee
    • Journal of Ocean Engineering and Technology
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    • v.33 no.2
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    • pp.168-177
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    • 2019
  • KRISO (Korea Research Institute of Ship & Ocean Engineering) started a project to develop the core algorithms for autonomous intervention using an underwater robot in 2017. This paper introduces the development of the robot platform for the core algorithms, which is an ROV (Remotely Operated Vehicle) type with one 7-function manipulator. Before the detailed design of the robot platform, the 7E-MINI arm of the ECA Group was selected as the manipulator. It is an electrical type, with a weight of 51 kg in air (30 kg in water) and a full reach of 1.4 m. To design a platform with a small size and light weight to fit in a water tank, the medium-size manipulator was placed on the center of platform, and the structural analysis of the body frame was conducted by ABAQUS. The robot had an IMU (Inertial Measurement Unit), a DVL (Doppler Velocity Log), and a depth sensor for measuring the underwater position and attitude. To control the robot motion, eight thrusters were installed, four for vertical and the rest for horizontal motion. The operation system was composed of an on-board control station and operation S/W. The former included devices such as a 300 VDC power supplier, Fiber-Optic (F/O) to Ethernet communication converter, and main control PC. The latter was developed using an ROS (Robot Operation System) based on Linux. The basic performance of the manufactured robot platform was verified through a water tank test, where the robot was manually operated using a joystick, and the robot motion and attitude variation that resulted from the manipulator movement were closely observed.

The Comparative Study on the Cosmic Life as the Inter-Relational Metaphor of the Ultimate Reality in East and West (서양의 영(Spirit)과 동양의 기철학과의 대화 : 내적 관계성의 메타포와 우주적 생명을 중심으로)

  • Shin, Eun Hee
    • (The)Study of the Eastern Classic
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    • no.32
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    • pp.245-278
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    • 2008
  • The purpose of this paper is to create an inter-religious dialogue between the Western Christian concept of the spirit and Eastern ch'i philosophy within the category of panentheism. The Hebrew term ruah means 'moving air' and 'wind' which derive from the particular experience of the ancient Hebrew people living in the desert. The Greek pnuema also means 'life' and 'wind' which denote the natural power. Both ruah and pneuma consist of the main idea of the spirit exploring the symbol of relationality of the divine in Western tradition. Eastern ch'i philosophy indicates a vital force for keeping the body and soul alive, which is unconscious and spontaneous. Ch'i as a vital force constitutes cosmogony and cosmology with the constant movement of yin and yang. Yin and Yang as representing earth and heaven are dynamic breaths, blending harmoniously to become all existence. The ethical implication of the inter-religious dialogue between the spirit and ch'i would be the integration and interconnection of heaven, earth, and human beings. The dialogue suggests becoming one body with nature and human community through embodying the non-dualistic spirit of life. The inter-relationality means that since all modalities of existence are made of the cosmic life, human beings are part of the divine cosmic process. This is related to degree of spirituality in the entire chain of being: rocks, trees, animals, humans, and goods represent different levels of spirituality based on the varying composition of the spirit and ch'i. All beings that internally embody with the spirit and ch'i are organically inter-connected, and they are integral part of a continuous process of transformation of life towards holistic liberation of human and nature community.

Analysis of the Manpyeong of the KyungHyang Shinmun and JoongAng Ilbo based on the May 18 Democratic Uprising (5·18민주화운동을 소재로 하는 경향신문과 중앙일보의 만평 분석)

  • Park, Kyung-Pyo
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.466-479
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    • 2021
  • Fake news is flooded with fake news that mixes untrue falsehoods in whole or in part. In order to create a frame for political and social purposes, news is mainly created by combining facts with fakes, or news is created for the purpose of incitement to encourage distortion and hatred. In particular, some media, including over-the-air broadcasting, are expressing their political bias in a specific direction without hesitation. Even if the press has political bias, if it is based on the delivery of facts, a trusted media environment can be achieved under the mutual checks of conservatives and progressives. The May 18 Democratic Uprising is a painful history and fact of modern history, leaving remuneration and progress. Nevertheless, there is still a view that the May 18 Democratic Uprising is regarded as 'democracy movement' and 'violence'. This study analyzed how the conservative JoongAng Ilbo and the progressive Kyunghyang Shinmun Manpyeong deal with the May 18 Democratic Uprising. The Manpyeong of the two newspapers differs greatly from the viewpoint of the May 18 Democratic Uprising. The liberal tendency of the Kyunghyang Shinmun Manpyeong has great significance in that it reveals the essence of the event and satirizes the subject. On the other hand, the conservative JoongAng Ilbo Manpyeong cannot approach the nature of the case or the object of satire due to ambiguity.

Ground Separation Test to Verify Separation Stability of External Fuel Tank (외부연료탱크의 분리 안정성 검증을 위한 지상 분리시험)

  • Kim, Hyun-gi;Hong, Seung-ho;Ha, Byung-geun;Kim, Sung-chan;Lee, Jun-won
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.99-104
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    • 2022
  • Aircraft pylon connects the engine or external stores to the main wing, and transfers the load acting on the pylon to the main structure of the aircraft. In particular, it should perform the function of separating the external store mounted on the pylon in case of emergency or mission performance. At this time, if the separation of the external store is not performed properly due to peripheral air flow or functional problems during the separation process of the external store, it may seriously impact the survivability of the aircraft. For this reason, to apply an external attachment to an aircraft, it is necessary to prove the stability of the external attachment in the separation situation in advance. In this paper, we present the result of the ground separation test performed to confirm that the external fuel tank, which is an external attachment, can be safely separated from the pylon. As a result of the test, the separation movement of the external fuel tank was measured with a high-speed camera, and the stability of the separation of the external fuel tank from the pylon were confirmed through the ground separation test. Additionally, the test result provides basic data for the stability evaluation of the separation of external attachments in actual aircraft.

Analysis of Research Trends in Relation to the Yellow Sea using Text Mining (텍스트 마이닝을 활용한 황해 관련 연구동향 분석연구)

  • Kyu Won Hwang;Kim Jinkyung;Kang Seung-Koo;Kang Gil Mo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.724-739
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    • 2023
  • Located in the sea area between South Korea, North Korea, and China, the Yellow Sea plays an important role from a geopolitical perspective, and recently, as the use of marine space in the Yellow Sea is expanding, its social and economic values have been increasing further. In addition, owing to rapid climate changes, the need for joint response and cooperation between Korea and China is increasing in various fields, including changes in the marine environment and marine ecosystem and generation and movement of air pollutants. Accordingly, in this study, core topics were derived from research papers with the Yellow Sea as a keyword, and research trends to date were explored through author network analysis. As a specific research method, research papers related to the Yellow Sea published between 1984 and 2021 were extracted from the Web of Science database and were classified into four periods to derive core topics using topic modeling, a type of text mining. Furthermore, the influences of major research communities, researchers, and research institutes in the appropriate fields were identified through analyzing the author network, and their implications were presented. The analysis results indicated that the core topics of research papers on the Yellow Sea had changed over time, and differences existed in the influence (centrality) of key researchers. Finally, based on the results of this study, this study aims to identify research trends related to the Yellow Sea, major researchers, and research institutes and contribute to research cooperation between Korea and China regarding the Yellow Sea in the future.