• Title/Summary/Keyword: Edge Cluster

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X-ray Absorption Spectra Analysis for the Investigation of the Retardation Mechanism of Iodine Migration by the Silver Ion Added to Bentonite (벤토나이트에 첨가한 은 이온에 의한 아이오딘 이동 저지 메커니즘 규명을 위한 X-선 흡수 스펙트라 분석)

  • Kim, Seung-Soo;Kim, Min-Gue;Baik, Min-Hoon;Choi, Jong-Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.3
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    • pp.201-205
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    • 2010
  • Most of iodine was captured by the block when NaI solution flowed through a bentonite block sorbed silver to retard the migration of iodine released from high-level radioactive wastes. In order to understand in detail the mechanism for the retardation of the iodine by the silver ion, X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) spectra of the silver sorbed bentonite before and after the contact with iodide were compared with those of AgO, $Ag_2O$ and AgI as references. This examination suggests that the silver ion sorbed on the bentonite is desorbed, and then it retards the migration of iodine by forming the cluster of AgI precipitate.

Optical properties of epitaxial $Gd_2$O_3:EU^{3+}$luminescent thin films depending on crystallinity ($Gd_2$O_3:EU^{3+}$ 형광체 박막의 결정성에 따른 발광특성 연구)

  • 장문형;최윤기;정권범;황보상우;장홍규;노명근;조만호;손기선;김창해
    • Journal of the Korean Vacuum Society
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    • v.12 no.4
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    • pp.275-280
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    • 2003
  • Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

An Empirical Study on the Distribution Park Strategy for Logistics-Hub in Northeast Asia (동북아 물류거점화를 위한 항만배후부지 구축전략에 관한 실증연구)

  • Yoon Byeong-Goo;Kwak Kyu-Seok;Ahn Ki-Myung;Kim Myung-Jae
    • Journal of Navigation and Port Research
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    • v.29 no.10 s.106
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    • pp.897-906
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    • 2005
  • The purpose of this research is to verify the strategic fitness and relevance of the distribution park for a hub port in Northeast Asia and to find a method to be a hub-port with a competitive edge. The strategic factor of distribution park development are policy, methodology and promotion method So these factors are analysed by structural equation model. The essential results of the research show that distribution park should be actually developed to produce value-added and to be port cluster.

Sportswear Purchase Decision Factors and Brand Preference among College Students (대학생의 스포츠웨어 구매결정요인과 브랜드 선호도)

  • Kim, Ki-Han
    • Fashion & Textile Research Journal
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    • v.11 no.4
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    • pp.583-591
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    • 2009
  • The purpose of this study was to examine the sportswear purchase decision factors and brand preference of college students. The subjects in this study were 614 college students who were selected by cluster random sampling from Daegu and North Gyeongsang Province. The collected data were analyzed by crosstab analysis, and the findings of the study were as follows: If a sportswear company has college students as a target market, first, the company needs to consider design and utility. Second, the company needs to expand internet sale while maintaining a strategy for centering on speciality shop and department store as for a sale of sportswear. Third, the college students themselves have a right of choice according to purchasing sportswear. Thus, a distribution company requires a direct marketing strategy targeting college students. Fourth, simple design of adding a fashion trend is needed. Fifth, the sportswear company needs to expand production and sale in jumpers and trousers based on T-shirts. Sixth, color in sportswear needs to be composed of design based on gray or black color. In order for a sportswear company to be adjusted to the global market environment here after, it requires an effort to continuously grasp consumers' trend and to apply new design and color. Also, the company will be able to be equipped with competitive edge by producing diversely functional products that are demanded by the segmented market.

Recognition of Lanes, Stop Lines and Speed Bumps using Top-view Images (탑뷰 영상을 이용한 차선, 정지선 및 과속방지턱 인식)

  • Ahn, Young-Sun;Kwak, Seong Woo;Yang, Jung-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.11
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    • pp.1879-1886
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    • 2016
  • In this paper, we propose a real-time recognition algorithm of lanes, stop lines and speed bumps on roads for autonomous vehicles. First, we generate a top-view using the image transmitted from a camera that is installed to see the front of a vehicle. To speed up the processing, we simplify the mapping algorithm in constructing a top-view wherein the region of interest (ROI) is concerned. The features of lanes, stop lines and speed bumps, which are composed of lines, are searched in the edge image of the top-view, then followed by labeling and clustering specialized to detect straight lines. The width of lines, distances from the center of a vehicle, and curvature of each cluster are considered to select final candidates. We verify the proposed algorithm on real roads using the commercial car (KIA K7) which is converted into an autonomous vehicle.

An Empirical Study on the Distribution Park Strategy for Northeast Asia Logistics-Hub (동북아(東北亞) 물류거점화(物流據點化)를 위한 항만배후부지(港灣背後敷地) 구축전략(構築戰略)에 관(關)한 실증연구(實證硏究))

  • Yun, Byeong-Goo;Kwak, Kyu-Seok;Ahn, Ki-Myung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.465-470
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    • 2005
  • The purpose of this research is to verify the strategic fitness and relevance of the distribution park for hub port in Northeast Asia and to find a method to be a hub-port with a competitive edge. The Strategic factor of distribution park development are policy, methodology and promotion method. So these factors are analysed by structural equation model. The essential results of the research show that distribution park should be actually developed to product value-added and connected to industry park to be port cluster.

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NUMERICAL ANALYSIS OF TWO- AND THREE-DIMENSIONAL SUBSONIC TURBULENT CAVITY FLOWS (2차원과 3차원 아음속 공동 유동 특성에 대한 수치적 연구)

  • Choi, Hong-Il;Kim, Jae-Soo
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.187-193
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    • 2007
  • The flight vehicles have cavities such as wheel wells and bomb bays. The flow around a cavity is characterized as unsteady flow because of the formation and dissipation of vortices due to the interaction between the freestream shear layer and cavity internal flow, the generation of shock and expansion waves. Resonance phenomena can damage the structures around the cavity and negatively affect aerodynamic performance and stability. In the present study, numerical analysis was performed for cavity flows by the unsteady compressible three dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with Wilcox's ${\kappa}\;-\;{\omega}$ turbulence model. The cavity has the aspect ratios of 2.5, 3.5 and 4.5 for two-dimensional case, same aspect ratios with the W/D ratio of 2 for three-dimensional case. The Mach and Reynolds numbers are 0.53 and 1,600,000 respectively. The flow field is observed to oscillate in the "shear layer mode" with a feedback mechanism. Based on the SPL(Sound Pressure Level) analysis of the pressure variation at the cavity trailing edge, the dominant frequency was analyzed and compared with the results of Rossiter's formula. The MPI(Message Passing Interface) parallelized code was used for calculations by PC-cluster.

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Load Balancing for Parallel Finite Element Analysis in Computing GRID Environment (컴퓨팅 그리드 시스템에서의 병렬 유한요소 해석을 위한 로드 밸런싱)

  • Lee,Chang-Seong;Im,Sang-Yeong;Kim,Seung-Jo;Jo,Geum-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.10
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    • pp.1-9
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    • 2003
  • In GRID environments, an efficient load balancing algorithm should be adopted since the system performances of GRID system are not homogeneous. In this work, a new two-step mesh-partitioning scheme based on the graph-partitioning scheme was introduced to consider the difference of system performance. In the two-step mesh-partitioning scheme, the system performance weights were calculated to reflect the effect of heterogeneous system performances and WEVM(Weighted Edge and vertex Method) was adopted to minimize the increase' of communications. Numerical experiments were carried out in multi-cluster environment and WAN (Wide Area Network) environment to investigate the effectiveness of the two-step mesh-partitioning scheme.

Robust Recognition of 3D Object Using Attributed Relation Graph of Silhouette's (실루엣 기반의 관계그래프 이용한 강인한 3차원 물체 인식)

  • Kim, Dae-Woong;Baek, Kyung-Hwan;Hahn, Hern-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.7
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    • pp.103-110
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    • 2008
  • This paper presents a new approach of recognizing a 3D object using a single camera, based on the extended convex hull of its silhouette. It aims at minimizing the DB size and simplifying the processes for matching and feature extraction. For this purpose, two concepts are introduced: extended convex hull and measurable region. Extended convex hull consists of convex curved edges as well as convex polygons. Measurable region is the cluster of the viewing vectors of a camera represented as the points on the orientation sphere from which a specific set of surfaces can be measured. A measurable region is represented by the extended convex hull of the silhouette which can be obtained by viewing the object from the center of the measurable region. Each silhouette is represented by a relation graph where a node describes an edge using its type, length, reality, and components. Experimental results are included to show that the proposed algorithm works efficiently even when the objects are overlapped and partially occluded. The time complexity for searching the object model in the database is O(N) where N is the number of silhouette models.

Flow Characteristics of Neutrally Buoyant Particles in 2-Dimensional Poiseuille Flow through Circular Capillaries

  • Kim, Young-Won;Jin, Song-Wan;Yoo, Jung-Yul
    • 한국가시화정보학회:학술대회논문집
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    • 2006.12a
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    • pp.7-10
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    • 2006
  • An experimental study has been conducted to quantitatively characterize the motion of neutrally buoyant particles in 2-dimensional Poiseuille flow through the micron-sized circular capillaries in the range of Re (Reynolds number) $\approx0.1\sim100$. $A{\mu}-PTV$ (Particle Tracking Velocimetry) system is adopted, which consists of a double-headed Nd:YAG laser, an epi-fluorescence microscope and a cooled CCD camera. Since high shear rate can be induced due to the scale effect even at low Re, it is shown that in micro scale neutrally buoyant particles in Poiseuille flow drift away from the wall and away from the center of the capillary. Consequently, particles accumulate at the equilibrium position of $0.52\sim0.64R$ with R being the radius of the capillary, which is analogous to that of tube flow in macro scale. There is a plateau in equilibrium position at small Re, while equilibrium position starts increasing at $Re\approx30$. The outermost edge of particle cluster is closer to the center of the capillary than that in previous studies due to low Re effect. The present study quantitatively presents characteristics of particle motion in circular capillaries. Furthermore, it is expected to give optimum factors for designing microfluidic systems that are to be used fur plasma separation from the blood.

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