• Title/Summary/Keyword: Spreading Characteristic

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The Role of Slits and Swirl Vanes on the Turbulent Flow Fields in Cone Type Gas Burner (콘형 가스버너의 난류유동장에 대한 슬릿과 스월베인의 역할)

  • Kim, Jang-Kweon;Jeong, Kyu-Jo
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.341-346
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    • 2001
  • The gun-type gas burner adopted in this study is generally composed of some slits and swirl vanes. Therefore, this paper is studied to investigate the effect of slits and swirl vanes on the turbulent flow fields in the horizontal plane of gas swirl burner with a cone type baffle plate measured by using X-probe from hot-wire anemometer system. This experiment is carried out at flow rate $450\;{\ell}/min$, which is equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of subsonic wind tunnel. When the burner has only swirl vanes, the axial mean velocity component shows the characteristic that spreads more remarkably toward radial direction than axial one, but when it has only slits, that is developed spreading more toward axial direction than radial one. Therefore, because the biggest speed is spurted in slits and it derive main flow toward axial direction encircling rotational flow that comes out from swirl vane that is situated on the inside of slits, both slits and swirl vanes composing of cone type gas burner act role that decreases the speed near slits and increases the flow speed in the central part of a burner. Moreover, because rotational flow by swirl vanes and fast jet flow by slits increase turbulent intensities effectively coexisting, the turbulent kinetic energy is distributed with a bigger size fairly near slits than burner models which have only slit or swirl vanes within X/R<0.6410.

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Analysis of Fake News in the 2017 Korean Presidential Election

  • Go, Seon-gyu;Lee, Mi-ran
    • Asian Journal for Public Opinion Research
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    • v.8 no.2
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    • pp.105-125
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    • 2020
  • The purpose of this paper is to analyze 1) who created and distributed fake news, 2) the distribution channels of fake news, 3) who fake news has targeted, and 4) the effects on voting and the impact of fake news on Korean politics. In South Korea, fake news was mainly created by candidates or election campaigns. The reason is that in the wake of the impeachment of President Park Guen Hye, all the political parties in Korea used fake news as a means of mobilizing supporters for each of their candidates or parties to gain an advantage in situations involving political divisions and confrontations between the pro-impeachment, progressive young generation and anti-impeachment, conservative senior generation. Voters' media usage patterns were polarized through social network services (SNS) media and television. Fake news was mostly received through these two media outlets. According to the spreading structure of fake news in Korea, the younger generation generally uses SNS posts intended for unspecified individuals, and the older generation uses closed SNS like KakaoTalk or Naver's BAND. In the end, it is typically characteristic of the older generation to spread fake news through existing offline human networks. In the 2017 presidential election, fake news has been confirmed to have the effect of mobilizing supporters for each political party. In the presidential election, an increase in voter turnout was confirmed among those in their 20s and those in their 60s or older. Evidently, fake news influenced the election of Moon Jae-In. The influence of fake news is expected to grow further as ideological polarization and consequent political polarization continues to intensify in South Korea.

Theoretical Basis and Application of the Neurac Technique Which Uses the Sling Exercise Therapy (슬링운동치료를 이 용한 Neurac 기법의 이론적 근거와 적용방법)

  • Kim, Suhn-Yeop;Kim, Taek-Yean
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.12 no.2
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    • pp.52-65
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    • 2006
  • Sling exercises therapy can speak as appliable comprehensive exercises therapy technique efficiently in general exercise field for injured worker's rehabilitation process and health improvement patient or athlete, injury or disease that have pain or dysfunction to neuromuscular system using that shake. At 1990 an early stage, because physical therapist and doctors of medical treatment developed country norway of north europe cooperate sling exercises therapy's concept trend spreading worldwide establishing theory newly based on scientific basic be. Musculoskeletal system, old man and young child's nervous system injurer's treatment and exercise and industry worker's rehabilitation process, athlete's rehabilitation etc. several fields introduced in early 2000s to Korea apply. Sling exercises therapy neuromuscular system disease continuous abatement as general concept of active exercise and treatment that use sling exercises equipment by purpose know can. This review article wishes to introduce about neuromuscular activation, "Neurac" technique that can speak as step developed more concept based on application principle etc, of basic sling exercises effort's change by suspension point's change that is concept, stability exercises principle, open kinetic chain exercises and closed kinetic chain exercises. Arranged about Plateau potential's characteristic and working mechanism and Neurac technique's application method that can say as Neurac technique's neuro-physiologic base, and presented treatment method of lumbar part disease and cervical part, shoulder joint part disease to application example. Because plateau potential forward player that induce using Neurac technique in part muscles that act role that keep spine surrounding stability in this article keeps muscle's contraction continuously, between global and local muscles, presented several study findings that can cause affirmative change in insufficient muscle adjustment state such as imbalance of muscles' action order. Expect that case studies that use this Neurac technique here after consist continuously.

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Analysis of the Molecular Event of ICAM-1 Interaction with LFA-1 During Leukocyte Adhesion Using a Reconstituted Mammalian Cell Expression Model

  • Han, Weon-Cheol;Kim, Kwon-Seop;Park, Jae-Seung;Hwang, Sung-Yeoun;Moon, Hyung-Bae;Chung, Hun-Taeg;Jun, Chang-Duk
    • Animal cells and systems
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    • v.5 no.3
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    • pp.253-262
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    • 2001
  • Ligand-receptor clustering event is the most important step in leukocyte adhesion and spreading on endothelial cells. Intercellular adhesion molecule-1 (ICAM-1) has been shown to enhance leukocyte adhesion, but the molecular event during the process of adhesion is unclear. To visualize the dynamics of ICAM-1 movement during adhesion, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 fused to a green fluorescent protein (IC1_GFP/CHO) and examined them under the fluorescence microscopy. The transfection of IC1_GFP alone in these cells was sufficient to support the adhesion of K562 cells that express $\alpha$L$\beta$2 (LFA-1) integrin stimulated by CBR LFA-1/2 mAb. This phenomenon was mediated by ICAM-1-LFA-1 interactions, as an mAb that specifically inhibits ICAM-1-LFA-1 interaction (RRl/l) completely abolished the adhesion of LFA-1* cells to IC1_ GFP/CHO cells. We found that the characteristic of adhesion was followed almost immediately (~10 min) by the rapid accumulation of ICAM-1 on CHO cells at a tight interface between the two cells. Interestingly, ICI_GFP/CHO cells projected plasma membrane and encircled approximately half surface of LFA-1+ cells, as defined by confocal microscopy. This unusual phenomenon was also confirmed on HUVEC after adhesion of LFA-1* cells. Neither cytochalasin D nor 2,3-butanedione 2-monoxime an inhibitor of myosin light chain kinase blocked LFA-1-mediated ICAM-1 clustering, indicating that actin cytoskeleton and myosin-dependent contractility are not necessary for ICAM-1 clustering. Taken together, we suggest that leukocyte adhesion to endothelial cells induces specialized form of ICAM-1 clustering that is distinct from immunological synapse mediated by T cell interaction with antigen presenting cells.

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Interfacial Durability and Acoustic Properties of Transparent xGnP/PVDF/xGnP Graphite Composites Film for Acoustic Actuator (음향 작동기를 위한 투명한 xGnP/PVDF/xGnP 그래핀 복합재료 필름의 계면 내구성 및 음향 특성)

  • Gu, Ga-Young;Wang, Zuo-Jia;Kwon, Dong-Jun;Park, Joung-Man
    • Composites Research
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    • v.25 no.3
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    • pp.70-75
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    • 2012
  • Interfacial durability and electrical properties of CNT, ITO or xGnP coated PVDF nanocomposites were investigated for acoustic actuator applications. The xGnP coated PVDF nanocomposite exhibited better electrical conductivity than CNT and ITO case due to the unique electrical property of xGnP, and this nanocomposite also showed good sound characteristics. Interfacial adhesion durability between either neat CNT or plasma treated CNT and plasma treated PVDF were measured by static contact angle, surface energy, work of adhesion, and spreading coefficient tests. The optimum acoustic actuation performance of xGnP coated PVDF nanocomposite was measured using sound level meter with changing radius of curvature and coating conditions. As compared to CNT and ITO, the xGnP was known as more appropriate acoustic actuator due to the characteristic electrical property. It is the most appropriate condition when the radius of curvature is 15 degree. Although sound characteristics were different with various coating thicknesses, it is possible to manufacture transparent actuator with good sound quality.

Study on Epidemic Warm Diseases with dampness of "OnByeongJoByeon" ("온병조변(溫病條辨)" 습류온병(濕類溫病)에 대한 고찰)

  • Park, Mi Sun;Kim, Yeong Mok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.803-811
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    • 2012
  • Oriental Medicine always attach great importance to the damp diseases. Dampness is related with many organs and many clinical diseases. The cause and the location of the damp disease, nature of the symptoms, combination with other pathogenic factors are very diverse. This article analyzed the concept, cause of disease, pathogenesis, characteristic of symptoms, treatment method and prescriptions of Epidemic Warm Diseases of dampness syndrome and cases of dampness-heat diseases based on the theories of Epidemic Warm Diseases and found that theories of Epidemic Warm Diseases have very wide area of application. Dampness is classified into cold-dampness and dampness-heat by combination of heat or cold. The dampness syndrome is related with organs such as lung, spleen, kidney, triple energizers and bladder, and affects liver and heart. The basic treatment methods are dispelling dampness turbidity and diffusing qi movement. The detail treatment methods are spreading lung qi with lightness and resolving dampness and excreting turbidity in upper energizer, opening and dipping down with pungent-bitter and diffusing qi movement and strengthening the spleen and stomach in the middle energizer, draining dampness with bland in the lower energizer. Warming Yang is the main method of treatment for cold-dampness and clearing heat is for dampness-heat with the assistant methods such as resolving dampness and promoting the flow of qi. 5. Acute fever, virus diseases, epidemic diseases among modern diseases are much related with the dampness-heat syndrome.

xPlaneb: 3-Dimensional Bitmap Index for Index Document Retrieval (xPlaneb: XML문서 검색을 위한 3차원 비트맵 인덱스)

  • 이재민;황병연
    • Journal of KIISE:Databases
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    • v.31 no.3
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    • pp.331-339
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    • 2004
  • XML has got to be a new standard for data representation and exchanging by its many good points, and the core part of many new researches and emerging technologies. However, the self-describing characteristic, which is one of XML's good points, caused the spreading of XML documents with different structures, and so the need of the research for the effective XML-document search has been proposed. This paper is for the analysis of the problem in BitCube, which is a bitmap indexing that shows high performance grounded on its fast retrieval. In addition, to resolve the problem of BitCube, we did design and implement xPlaneb(XML Plane Web) which it a new 3-dimensional bitmap indexing made of linked lists. We propose an effective information retrieval technique by replacing BitCube operations with new ones and reconstructing 3-dimensional array index of BitCube with effective nodes. Performance evaluation shows that the proposed technique is better than BitCube, as the amount of document increases, in terms of memory consumptions and operation speed.

A Study on the Integrity Assessment of Bare Concrete Bridge Deck based on the Attenuation of Radar Signals (레이더 신호의 감쇠특성을 고려한 일체식 콘크리트 교량 바닥판의 상태평가 방법 고찰)

  • Rhee, Ji-Young;Choi, Jae-Jin;Kim, Hong-Sam;Park, Ko-Eun;Choi, Myeong-Jin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.84-93
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    • 2016
  • The signal characteristic of radar wave on concrete decks is determined by the attenuation of the radar due to the conversion of EM(Electromagnetic) energy to thermal energy through electrical conduction, dielectric relaxation, scattering, and geometric spreading. In this study, it is found that the attenuation of radar signal received on top rebars in bare deck concrete with 2 way travel time shows a general decreasing linear trend because of its same relative permittivity and conductivity. The radar signal after depth-normalization, can then be interpreted as being principally influenced by the content of chlorides penetrating cover concrete, which caused corrosion of rebars in bridge decks.

Robust Anti Reverse Engineering Technique for Protecting Android Applications using the AES Algorithm (AES 알고리즘을 사용하여 안드로이드 어플리케이션을 보호하기 위한 견고한 역공학 방지기법)

  • Kim, JungHyun;Lee, Kang Seung
    • Journal of KIISE
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    • v.42 no.9
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    • pp.1100-1108
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    • 2015
  • Classes.dex, which is the executable file for android operation system, has Java bite code format, so that anyone can analyze and modify its source codes by using reverse engineering. Due to this characteristic, many android applications using classes.dex as executable file have been illegally copied and distributed, causing damage to the developers and software industry. To tackle such ill-intended behavior, this paper proposes a technique to encrypt classes.dex file using an AES(Advanced Encryption Standard) encryption algorithm and decrypts the applications encrypted in such a manner in order to prevent reverse engineering of the applications. To reinforce the file against reverse engineering attack, hash values that are obtained from substituting a hash equation through the combination of salt values, are used for the keys for encrypting and decrypting classes.dex. The experiments demonstrated that the proposed technique is effective in preventing the illegal duplication of classes.dex-based android applications and reverse engineering attack. As a result, the proposed technique can protect the source of an application and also prevent the spreading of malicious codes due to repackaging attack.

Trend of Technology in Video Surveillance System

  • Song, Jaemin;Park, Arum;Lee, Sae Bom
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.6
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    • pp.57-64
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    • 2020
  • Video surveillance is consists of cameras, transmission devices, storage and playback devices, and is used for crime prevention and disaster monitoring. Recently, it has been spreading to a wide variety of fields, and has developed into an intelligent video surveillance system that can automatically recognize or track characteristic objects of people and things. The purpose of this study was to investigate the cases of video surveillance service applying the latest technology by dividing it into the home, public, and private sectors. also this study tried to investigate and research what advantage it brings from a business perspective. By looking at the cases introduced in this study, it was confirmed that the viedo security service is developing intelligently, such as excellent compatibility with CCTV, multiple video surveillance, CCTV screen motion detection, and alarm through automatic analysis.