• 제목/요약/키워드: Key player

검색결과 106건 처리시간 0.029초

Endothelial Cell Products as a Key Player in Hypoxia-Induced Nerve Cell Injury after Stroke

  • Cho, Chul-Min;Ha, Se-Un;Bae, Hae-Rahn;Huh, Jae-Taeck
    • Journal of Korean Neurosurgical Society
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    • 제40권2호
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    • pp.103-109
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    • 2006
  • Objective : Activated endothelial cells mediate the cascade of reactions in response to hypoxia for adaptation to the stress. It has been suggested that hypoxia, by itself, without reperfusion, can activate the endothelial cells and initiate complex responses. In this study, we investigated whether hypoxia-induced endothelial products alter the endothelial permeability and have a direct cytotoxic effect on nerve cells. Methods : Hypoxic condition of primary human umbilical vein endothelial cells[HUVEC] was induced by $CoCl_2$ treatment in culture medium. Cell growth was evaluated by 3,4,5-dimethyl thiazole-3,5-diphenyl tetrazolium bromide [MTT] assay Hypoxia-induced products [$IL-1{\beta},\;TGF-{\beta}1,\;IFN-{\gamma},\;TNF-{\alpha}$, IL-10, IL-6, IL-8, MCP-l and VEGF] were assessed by enzyme-linked immunosorbent assay. Endothelial permeability was evaluated by Western blotting. Results : Prolonged hypoxia caused endothelial cells to secrete IL -6, IL -8, MCP-1 and VEGF. However, the levels of IL -1, IL -10, $TNF-{\alpha},\;TGF-{\beta},\;IFN-{\gamma}$ and nitric oxide remained unchanged over 48 h hypoxia. Hypoxic exposure to endothelial cells induced the time-dependent down regulation of the expression of cadherin and catenin protein. The conditioned medium taken from hypoxic HUVECs had the cytotoxic effect selectively on neuroblastoma cells, but not on astroglioma cells. Conclusion : These results suggest the possibility that endothelial cell derived cytokines or other secreted products with the increased endothelial permeability might directly contribute to nerve cell injury followed by hypoxia.

Radiosity model과 AI 알고리즘을 이용한 모바일 게임 구현 (Implementation of 3D mobile game using radiosity model and AI algorithm)

  • 김성동;진성아;조데레샤
    • 한국게임학회 논문지
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    • 제17권1호
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    • pp.7-16
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    • 2017
  • 3D 게임그래픽 표현기술은 게임콘텐츠발전과 함께 콘텐츠 분야에서 중요한 요소가 되었다. 특히 게임 캐릭터 표현 기술은 사실적인 그래픽 기술과 시각적인 즐거움을 주는 것 이외에 게임을 진행하는 게임에 대한 몰입도의 중간 단계역할을 하며 플레이어가 마치 게임 속에서 영웅적인 모험을 즐길 수 있도록 착각을 만들어 낸다. 3D 게임에 있어서 게임캐릭터의 높은 완성도는 개발과정 가운데 캐릭터 설정작업의 세심한 디테일작업과 신중함이 주요요인으로 작용한다[3]. 본 논문에서는 게임구현을 위하여 인지적 AI 알고리즘이 적용된 3D 유니티 게임 엔진을 사용하여 radiosity의 수학적인 모델과 기본적인 radiosity 모델, 점진적 개선 radiosity 모델 기법을 방법론을 소개하고, 모바일 게임에 적용한 캐릭터 표현기법을 제안하려고 한다. 게임엔진에 실제적으로 적용하여보니 렌더링과정과 모의실험에서 표면의 투영도는 게임콘텐츠 환경의 조명도에 따라 변화됨을 발견 할 수 있어서, 전체적으로 질 높은 게임캐릭터가 완성되었음이 확인 되었다.

고스트들의 협력전술에 의한 팩맨게임 난이도 제고 (Making Levels More Challenging with a Cooperative Strategy of Ghosts in Pac-Man)

  • 최태영;나현숙
    • 한국게임학회 논문지
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    • 제15권5호
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    • pp.89-98
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    • 2015
  • NPC, 특히 적 캐릭터들의 인공지능은 게임의 설계 단계에 있어 난이도를 조절하기 위해 핵심적인 요소이다. 지능적인 적들은 게임을 보다 도전적으로 만들 뿐 아니라, 동일한 게임 환경에서도 유저들에게 다양한 경험을 제공할 수 있다. 오늘날 대부분의 게임 유저들은 다수의 적들과 상호작용을 하기 때문에, 적 캐릭터들의 협업을 제어하는 것은 이전 어느 때보다 그 중요성이 크다고 할 수 있다. 본 연구는 팩맨 게임의 적 인공지능에 구현될 수 있는 A* 알고리즘 기반의 협력전술을 제안한다. 17명의 피실험자로부터 얻은 설문 결과는 제안된 협력전술을 따르는 적으로 구성된 레벨이, 기존 팩맨게임에서의 적들 또는 비협력적인 적들로 구성된 레벨들보다 더 어렵고 흥미로웠음을 보여준다.

Water, Energy, Cooperation, and Conflict inthe Kura-Araks Basin of the South Caucasus

  • Campana, Michael E.
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2011년도 학술발표회
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    • pp.3-3
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    • 2011
  • After the dissolution of the Soviet Union, the Kra-Araks Basin (KAB) became an international river basin with respect to the South Caucasus states of Armenia, Azerbaijan, and Georgia. However, there are no agreements regarding water allocation, water quality, or ecosystem maintenance among the aforementioned riparians. The main water problems in the basin include not only water quantity and quality, but also the lack of joint management. The aforementioned countries share many similar circumstances: location in a politically unstable but strategic region bureaucratic and structural issues; and more importantly, ongoing ethnic and related conflicts. Despite these obstacles, the countries recognize that they depend greatly on the basin, whose waters they must share. To that end, they proposed and participated in the joint NATO-OSCE South Caucasus River Monitoring (SCRMP) project between 2002 and 2009.The SCRMP sought to investigate and characterize the surface water quality in the KAB by providing equipment and training to all three countries. Several years' worth of water quality data were collected in the KAB: major ions; heavy metals; POPs (persistent organic pollutants); and radionuclides; The North Atlantic Treaty Organization (primary funder) and the Organization for Security and Co-operation in Europesupported the SCRMP not only to build capacity but also to promote cooperation and minimize conflict over water and other resources, thus providing a measure of security for Europe and other regions. The South Caucasus is a strategically-important region, functioning as a bridge between Asia and Europe. Energy-rich Azerbaijan seeks to become a key player in trade by serving as a transportation and energy hub between the energy and mineral-rich Central Asian KUT countries (Kazakhstan, Uzbekistan, and Turkmenistan) and Western Asia, Europe, and other areas. The presentation will summarize the scientific results of the SCRMP, elucidate the regional water-energy-security nexus, discuss future work in the region, and explain why the world needs to be concerned about the KAB and the entire South Caucasus.

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The Application of Make-up through Optical Illusion - Focused on Lineal Illusion -

  • Cho, Ko-Mi;Cho, Jin-A
    • 패션비즈니스
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    • 제7권6호
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    • pp.57-66
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    • 2003
  • With the occurrence of interest in image-presentation that helps express one's individuality in several place in our society, it has affected make-up field. Now, make-up is getting to be recognized as a key role player that reflects our social and cultural concerns not only by presenting a appropriate one that is proper when to use and what for, but also presenting individualistic images that are able to express one's attractiveness free from a last plain concept that meant merely applying cosmetics to one's face is makeup. Like above, the reason that a change for consciousness of the function of make-up was possible is a noticeable outcome that results from the difference before and after make-up. In other word, with the help of Corrective Make-up that makes use of optical illusion, the analytic research for features could have been carried out systematically, therefore, women get to present their beauty of innate facial shape and features at their pleasure. The basic principles of the Corrective Make-up, which was introduced to satisfy the purpose of the existing make-up take advantage of lines and colors that are part of the optical illusion. The nature of direction and movement was expressed by the direction and angle of lines and the colors are also able to induce the variation of images depend on the whole color around them or contrastive color around. This thesis is mainly about optical illusion through lines that are part of elements that induce the optical illusion and deals with phenomena that occur when we apply lines that are part of design into the make-up. And this is written for the purpose of establishing the last basis of make-up more scientifically and systematically through the research for the variation when we apply the nature of lines into our features and deriving facial image variation from it. This is also for study into the role of make-up as for psychological effect that is able to make facial images look different when the optical illusion with possible visual errors is applied into it. In conclusion, we can say "Make-up is optical illusion through visual elements such as lines, surfaces, books, touch and so on."

컨셉추얼 아트의 조형적 특징이 반영된 현대패션에 관한 연구 (A Study on the Contemporary Fashion based on Characteristics of Conceptual Art)

  • 권자영;금기숙
    • 복식
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    • 제57권7호
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    • pp.70-83
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    • 2007
  • Contemporary fashion design has been made a new attempt to extend restricted expressions through fusion with other genres in art. The recognition of fashion has recently been changed not only product but as a piece of work in specific value, concept and meaning created by fashion designer. It is observed that the contemporary fashion design has a notion to persue formative intentions and manners of Conceptual Art in Post-modern era. This study is to define this region of fashion design represented in cultural phenomena as 'Conceptual Fashion', also analyze the formative feature of this from a point of view in Conceptual art. The results which are analyzed according to outward techniques and forms, meanings and elements immanent in aesthetic contemplation of conceptual fashion lead to four distinctive things in such as anti-form, intervention and appropriation, metaphor and detour, process and series. The intrinsic values in conceptual fashion through aesthetic contemplation are indicated the four significant values in the following: the pluralistic interpretation, the parody and amusement, the pursuit of essence and truth and the participation and interaction. Conceptual fashion design is appeared complex not doing separate through classified formative features previously. And It has been evolved as a indeterminate concept which is able to variable elucidation by a non-player, as a instrument for communication on fashion culture which is aggrandized. The purpose of this study is to present of theoretical foundation about Conceptual fashion design and also to make proper understanding about interrelationship between contemporary fashion and art.

The influence of anthropogenic disturbances and watershed morphological characteristics on Hg dynamics in Northern Quebec large boreal lakes

  • Moingt, M.;Lucotte, M.;Paquet, S.;Beaulne, J.S.
    • Advances in environmental research
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    • 제2권2호
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    • pp.81-98
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    • 2013
  • Mercury (Hg) dynamics in the boreal environment have been a subject of concern in recent decades, due to the exposure of local populations to the contaminant. Land use, because of its impact on mercury inputs, has been highlighted as a key player in the sources and eventual concentrations of the heavy metal. In order to evaluate the impact of watershed disturbances on Hg dynamics in frequently fished, large boreal lakes, we studied sediment cores retrieved at the focal point of eight large lakes of Qu$\acute{e}$bec (Canada), six with watersheds affected by land uses such as logging and/or mining, and two with pristine watersheds, considered as reference lakes. Using a Geographical Information System (GIS), we correlated the recent evolution of land uses (e.g., logging and mining activities) and morphological characteristics of the watershed (e.g., mean slope of the drainage area, vegetation cover) to total Hg concentrations (THg) in sedimentary records. In each core, THg gradually increased over recent years with maximum values between 70 and 370 ng/g, the lowest mercury concentrations corresponding to the pristine lake cores. The Hg Anthropogenic Sedimentary Enrichment Factor (ASEF) values range from 2 to 15. Surprisingly, we noticed that the presence of intense land uses in the watershed does not necessarily correspond to noticeable increases of THg in lake sediments, beyond the normal increment that can be attributed to Hg atmospheric deposition since the beginning of the industrial era. Rather, the terrestrial Hg inputs of boreal lakes appear to be influenced by watershed characteristics such as mean slopes and vegetation cover.

폐기물매립장 침출수내 미생물군집 구조 해석을 위한 T-RFLP의 활용 (T-RFLP Analysis of Microbial Community Structure in Leachate from Landfill Sites)

  • 유재철;;;이태호
    • 대한환경공학회지
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    • 제32권4호
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    • pp.369-378
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    • 2010
  • 폐기물매립장의 안정화에는 미생물이 중요한 역할을 수행한다. 폐기물매립장에서 미생물군집 변화 모니터링에 말단 제한절편다형성(Terminal Restriction Fragment Length Polymorphism; T-RFLP)법의 활용 가능성을 평가하고자 박테리아의 16S rDNA 서열에 기초한 T-RFLP법으로 4개의 폐기물매립장 내부에서 채취한 침출수의 미생물군집 구조를 조사하였다. T-RFLP법을 사용하여 해석한 침출수 내 우점 미생물군집 구조와 일반적으로 널리 사용되고 있는 16S rDNA 클론 해석법에 의한 우점 미생물군집구조는 유사하였다. 또한, T-RFLP법을 이용하여 폐기물매립장의 구조, 매립 폐기물 종류, 운영기간이 다른 폐기물매립장 침출수의 우점 미생물군집 구조가 서로 다르게 나타나는 것을 확인 할 수 있었다. 따라서 T-RFLP법을 사용하여 폐기물매립장 침출수내 미생물군집 구조를 장기적으로 모니터링 한다면 많은 비용과 시간이 소요되는 클론해석법의 반복적인 수행 없이도 비교적 간단하게 폐기물매립장의 안정화 정도를 평가할 수 있을 것으로 기대한다.

FXRα Down-Regulates LXRα Signaling at the CETP Promoter via a Common Element

  • Park, Sung-Soo;Choi, Hojung;Kim, Seung-Jin;Kim, Ok Jin;Chae, Kwon-Seok;Kim, Eungseok
    • Molecules and Cells
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    • 제26권4호
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    • pp.409-414
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    • 2008
  • The cholesteryl ester transfer protein (CETP), a key player in cholesterol metabolism, has been shown to promote the transfer of triglycerides from very low density lipoprotein (VLDL) and low density lipoprotein (LDL) to high density lipoprotein (HDL) in exchange for cholesterol ester. Here we demonstrate that farnesoid X receptor ${\alpha}$ ($FXR{\alpha}$; NR1H4) down-regulates CETP expression in HepG2 cells. A $FXR{\alpha}$ ligand, chenodeoxycholic acid (CDCA), suppressed basal mRNA levels of the CETP gene in HepG2 cells in a dose-dependent manner. Using gel shift and chromatin immunoprecipitation (ChIP) assays, we found that $FXR{\alpha}$ could bind to the liver X receptor ${\alpha}$ ( $LXR{\alpha}$; NR1H3) binding site (LXRE; DR4RE) located within the CETP 5' promoter region. $FXR{\alpha}$ suppressed $LXR{\alpha}$-induced DR4RE-luciferase activity and this effect was mediated by a binding competition between $FXR{\alpha}$ and $LXR{\alpha}$ for DR4RE. Furthermore, the addition of CDCA together with a $LXR{\alpha}$ ligand, GW3965, to HepG2 cells was shown to substantially decrease mRNA levels of hepatic CETP gene, which is typically induced by GW3965. Together, our data demonstrate that $FXR{\alpha}$ down-regulates CETP gene expression via binding to the DR4RE sequence within the CETP 5' promoter and this $FXR{\alpha}$ binding is essential for $FXR{\alpha}$ inhibition of $LXR{\alpha}$-induced CETP expression.

PCIe Non-Transparent Bridge 인터페이스 기반 링 네트워크 인터커넥트 시스템 구현 (Implementation of Ring Topology Interconnection Network with PCIe Non-Transparent Bridge Interface)

  • 김상겸;이양우;임승호
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제8권3호
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    • pp.65-72
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    • 2019
  • HPC(High Performance Computer)은 다수의 계산노드를 초고성능 상호연결망으로 연결하여 클러스터 시스템으로 구성된 시스템이다. 이러한 HPC 시스템에서 사용하는 계산 노드 간의 연결 네트워크 기술로는 Infiniband, Ethernet 등의 기술이 많이 사용된다. 최근 PCIe 표준의 발전으로 인해서 컴퓨터 호스트는 고속의 주변 장치 디바이스를 주로 PCIe Bridge 인터페이스에 연결하여 사용한다. PCIe 표준 기술 중 컴퓨터 노드 간의 직접 연결하는 방식으로 Non-Transparent Bridge(NTB) 기반의 인터콘넥션 표준이 존재한다. 그러나 NTB의 기본 표준은 두 노드 간에 분리된 메모리를 제공하는 방식이기 때문에 다중 노드를 직접 연결하기 위해서는 추가된 구성 방법이 필요하다. 본 논문에서는 다중 NTB 포트에 직접 연결된 다수의 호스트들 간에 무스위치 네트워크를 구성하여 NTB 통신을 이용한 데이터 공유 방법의 설계와 구현에 대해서 다룬다. 각 호스트에 연결된 두 개의 NTB포트를 이용해서 링 네트워크를 구성하고, 링 네트워크 상에서 NTB 인터컨넥션을 이용한 데이터 공유 방식의 구현을 하였다. 이와 같이 PCIe NTB 기반 무스위치 네트워크를 통해서 기존의 인터커넥트 네트워크에 비해서 Cost-Effective한 HPC 상호연결망을 구성할 수 있다.