• Title/Summary/Keyword: Boundary Preservation

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Mesh Simplification for Volume and Boundary Preservation (볼륨과 경계보존을 고려한 메쉬 간략화)

  • 조진화;김성수;김영택
    • Proceedings of the Korean Information Science Society Conference
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    • 1999.10b
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    • pp.583-585
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    • 1999
  • 대부분의 3차원 모델을 가시화해주기 위한 시스템들은 삼각 메쉬를 기반으로 한 모델 표현법을 사용하고 있다. 이러한 시스템들은 복잡한 3차원 모델을 원격 엑세스할 때에는 모델을 가공하지 않으면 전송 및 랜더링시에 많은 제약이 따른다. 이러한 전송 시간과 랜더링 시간, 저장공간을 줄이기 위해 모델을 간략화하거나 압축하는 많은 기법들이 소개되어져 왔다. 본 논문에서는 메쉬 간략화를 위해 소개되어진 많은 다른 방법에서 사용한 에지 축약(Edge Collapse) 기반의 간략화 알고리즘을 제시한다. 기본적인 접근 방법으로는 기하학적인 메쉬 구성요소들 중에서 에지의 특성에 따라 제거 기준을 설정한 후 간략화해 나간다. 에지 축약을 위한 우선순위와 축약 이후 새로운 정점의 위치는 원본 모델을 참조하지 않고 간략화 단계의 모델에서 삼각형의 연결성(connectivity)과 정점의 위치만을 이용하여 계산하였다. 실제 이 방법은 방대한 다각형 메쉬를 간략화할 경우 메모리를 효율적으로 이용할 수 있으며, 처리 속도를 개선할 수 있다. 또한, 간략화이후에도 원본 모델의 위상(topology)을 유지할 수 있는 기법을 제시하고 있다. 세가지 모델에 대한 실험 결과에서 기하학적 에러(geometric error)를 최소화하였고, Heckbert가 제안한 방법(QSlim V2.0)과의 비교에서는 처리 속도가 개선되었다.

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Analysis of Mechanical Behavior of Nanowire by $Nos\acute{e}-Poincar\acute{e}$ Molecular Dynamics Simulation ($Nos\acute{e}-Poincar\acute{e}$ 분자 동역학 알고리즘을 이용한 나노 와이어의 역학적 거동 해석)

  • Lee, Byeong-Yong;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.506-511
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    • 2007
  • Mechanical behavior of copper nanowire is investigated. An FCC nanowire model composed of 1,408 atoms is used for MD simulation. Simulations are performed within NVT ensemble setting without periodic boundary conditions. $Nos\acute{e}-Poincar\acute{e}$ MD algorithm is employed to guarantee preservation of Hamiltonian and temperature. Numerical tensile tests of Nanowire are carried out with constant strain rate. Additionally, temperature and strain rate effects are considered. Stress-strain curve is constructed from the calculated Cauchy stresses and specified strain values. In (22,4,4) Copper nanowire, non-linear behavior appears around ${\epsilon}\simeq0.09.$ At this instance, starting of structural reorientations are observed. At the onset of reorientation, the modulus characteristics are also investigated.

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Analysis of Mechanical Behavior of Nanowire by Molecular Dynamics Simulation (분자동역학을 이용한 나노 와이어의 역학적 거동 해석)

  • Lee, Byeong-Yong;Cho, Maeng-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.433-438
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    • 2007
  • Mechanical behavior of copper Nanowire is investigated, An FCC Nanowire model composed of 1,408 atoms is used for NID simulation, Simulations are performed within NVT ensemble setting without periodic boundary conditions, Nose-Poincare MD algorithm is employed to guarantee preservation of Hamiltonian. Numerical tensile tests are carried out with constant strain rate, Stress-strain curve is constructed from the calculated Cauchy stresses and specified strain values, Non-linear behavior appears around $\varepsilon$=0.064, At this instance, starting of structural reorientations are observed.

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An Eedge-Based Adaptive Morphology Algorithm for Image Nosie Reduction (에지 정보를 이용한 잡음 제겅용 적응적 수리 형태론 알고리즘)

  • 김상희;문영식
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.3
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    • pp.84-96
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    • 1997
  • In this paper an efficient morphologica algorithm for reducing gaussian and impulse noise in gray-scale image is presented. Based on the edge information the input image is partitioned into a flat region and an edge region, then different algorithms are selectively applied to each region. in case of impulse noise, MGR (morphologica grayscale reconstruction) algorithm with directional SE (structuring element) is applied to the flat region. For theedge region opening-closing (closing-opening) is used instead of dialation (erosion), so that the remaining noise around large objects can be removed. In case of gaussian noise, 5*5 OCCO(opening closing closing opening) and 3*3 DMF(directional morphological filter ) are used for the flat region and the edgeregion, respectively. In order to remove discontinuity at the edge boundary, the algorithm uses 3*3 OCCO around the edge region to reconstruct the final image. Experimetnal results have shown that the proposed algorithm achieves a high performance in terms of noise removal, detail preservation, and NMSE.

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Preliminary Study for Tidal Flat Detection in Yeongjong-do according to Tide Level using Landsat Images (Landsat 위성을 이용한 조위에 따른 영종도 갯벌의 면적 탐지에 관한 선행 연구)

  • Lee, Seulki;Kim, Gyuyeon;Lee, Changwook
    • Korean Journal of Remote Sensing
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    • v.32 no.6
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    • pp.639-645
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    • 2016
  • Yeongjong-do is seventh largest island in the west coast of Korea which is 4.8 km away in the direction of south-west from Incheon. The mudflat area around the Yeongjong-do has variable dimension according to tide level. In addition, Yeongjong-do is important area with high environmental value as wintering sites for migratory birds. The mudflat of Yeongjong-do is also meaningful region because it is used as place of education and tourist attraction. But, there are increasing concerns about preservation of mudflat area caused by artificial development such as land reclamation project and Incheon airport construction. In this paper, mudflat area was detected using Landsat 7 ETM+ images that United States Geological Survey (USGS) is providing the data in 16 days period. The false color composite was made from band 7, 5, and 3 that could dividing boundary between water and land for the purpose of appearance of boundary line in mudflat region. This area was calculated using results of classification based on false color composite images and was digitized through repetitive algorithm during research of period. Therefore, the change of northeastern area in Yeongjong-do was detected according to tide level during 16 years from 2000 to 2015 on the basis of providing period at tide station. This paper will expect as indicator for range of area in same tide level prior to the start of the research for preservation of mudflat. It will be also scientific grounds about change of mudflat area caused by artificial development.

Research Trends Regarding Fisheries' Biological Resources in Korean Coastal Areas (우리나라 수산생명자원 연구동향)

  • Oh, Hyun Taik;Youn, Seok-Hyun;Chung, Mi Hee;Lee, Won Chan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.1
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    • pp.1-9
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    • 2013
  • Fisheries' biological resources were considered public resources before the 1990s. Every country could access and use these resources without regulation. However, the United Nations adopted the Convention on Biological Diversity and the privileges and rights to these resources were attributed to countries. This research starts with the research background and social and academic value of "The Jasan Eobo (or Report on Marine Organisms in the Coastal Waters near Heuksan Island)" by Jeong Yak-Jeon, who pioneered the new field of Fisheries Science and Marine Biology in Korea in the early 1800s. We also searched for recent results from the Marine Bio-Diversity Research Activities of the Korean National Council for Conservation of Nature (KNCCN) and the Ministry of Maritime Affairs and Fisheries (MOMAF). KNCCN reported that marine bio-diversity comprised approximately 6,500 species in 1996, and the Ministry of Maritime Affairs and Fisheries reported there were about 10,000 species in 2007. Among these marine species, plankton account for about 25%, seaweeds 11%, invertebrates 52%, and vertebrates 12% in Korean Coastal Areas. The Ministry for Food, Agriculture, Forestry, and Fisheries (MIFAFF) enacted a law for Agriculture and Fisheries Resources Management in 2012; this law includes the preservation of marine ecosystems, the conservation of wetlands and the preservation of fisheries resources, and describes the boundary of taxonomy for new species and unknown species that could be identified in the near future. To follow the new regulation for Access to General Resources and Benefit-Sharing, this research suggests (1) the importance of taxonomy for new species and unknown species as a goal of "No Name = No Information", (2) integrated research on bio-diversity, species distributions and the abundance of fisheries resources, both in local areas and in Korean Coastal Areas, and (3) the observance of international regulations or agreements for benefit-sharing without additional damage in the future.

Quality Characteristics of Naengmyon Added with Persimmon (Diospyos kaki L. folium) Leaf Powder (감잎분말을 첨가한 냉면의 품질 특성)

  • Nam Seng-Goo;Lee Bo-Su;Park Ju-Sek;Lee Won-Young
    • Food Science and Preservation
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    • v.13 no.3
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    • pp.337-343
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    • 2006
  • This study was conducted to develop naengmyon added with persimmon leaf powder. To find out the proper mixing ratio, physicochemical properties were investigated. There was a little difference in water binding capacity between control and naengmyon added with persimmon leaf powder. Amylogram showed that initial pasting temperature and peak point value were increased as increment of adding amount of persimmon leaf powder. After cooking, the weight of a naengmyon was increased but cooking loss and turbidity were decreased with increment of persimmon leaf powder. At a glance of color difference values, there was a distinctive boundary near at 6%. But similar at over 6% as increasing adding amount of persimon leaf powder texture characteristics such as hardness, adhesiveness, cohesiveness, springness and gumminess were declined. From overall experimental result, the proper mixing ratio of persimmon leaf powder for naengmyon was 4%.

Exploring Discourse and Issue on the Policy of England Greenbelt - Delivering Opportunities for Housing Development and Recreation - (잉글랜드 그린벨트 정책 담론과 쟁점 분석 - 주택 개발과 여가 기회를 중심으로 -)

  • Nam, Jin-Vo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.24 no.3
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    • pp.1-18
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    • 2021
  • England's green belt policy as it delivered its framework to designating the development restriction zones(DRZ) in Korea is the key to address issues which try to change green belt boundary or/and housing development. Therefore it should necessarily be reviewed on the understanding of how England has been formulating a national policy to deal with the issues focusing on opportunities for housing development and recreation. This study explored the discourse and framework of England's green belt policy as well as driver changes of housing development and recreation. Results show several characteristics of England's green belt policy which are civil society consensus on conservation and management, limited small-scale housing development through management of release rates, a systematic procedure for application and approval, open-recreation space expansion and utilisation under the premise of conservation of natural green areas, and management structure by the involvement of NGO organisations. Therefore, five suggestions can be delivered to developing Korea's DRZ frameworks: first, preceding social consensus on the preservation value of development-restricted zones, second, addressing housing shortages in different alternatives e.g.) environmental-friendly small-scale housing, third, institutionalising the total proportion of release, fourth, establishing an open-recreation space, fifth, introducing expanded public-private partnerships. Ultimately securing the legitimacy of the nation's development-restricted zone system can contribute positively to the environment preservation and human health by promoting public leisure activities in terms of the recent increase in external activities caused by the Covid-19 crisis. Concluding remarks are here that the understanding of England's green belt policy can be delivered to and help formulate domestic policy addressing current issues.

Study on Heating Load Characteristics and Thermal Curtain Effects for Simple Silkworm Rearing Houses(II) -Effects of the Thermal Curtain on Energy Preservation and Review of its Application- (간역잠실(簡易蠶室)의 난방부하특성(暖房負荷特性) 및 보온(保溫)커튼 설치(設置)효과에 관한 연구(硏究)(II) -보온(保溫)커튼의 열(熱) 절감(節減) 효과(効果) 및 적응성(適應性) 검토(檢討)-)

  • Choe, K.J.;Jung, D.H.;Park, K.K.
    • Journal of Biosystems Engineering
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    • v.16 no.1
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    • pp.83-89
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    • 1991
  • One of the most serious problems in Korean sericulture farms is to improve the adiabatic conditions for the simple silkworm rearing houses which has been widely adapted since early 1980'. Thus, this study is aimed to solve the problems by selecting the thermal screen material and by finding the method of its instalation. For the study, 4 kinds of materials which are (1) TE005,(2) NW60, (3) NW300 and (4) AL110 are selected and 4 different types of methods which are surrounding boundary of rearing bed(type A), surrounding inside of wall and ceiling (type B), installing on inside of wal ony (type C) and installing on ceiling Inly (type D) are installed. Decision criteria of the best combination of screen material and installation methods is made by calculating the heating load coefficients and by testing the application at the simple silkworm rearing houses. The obtained results are summarized as follows ; 1. The effect of thermal screen on reducing the thermal energy is remarkable. It saves energy more 50% than unscreened simple silkworm rearing houses. 2. From a stand point of a good screed material on thermal energy reduction, the NW300, AL110 and PE005 are recommanded materials. However, NW60 and PE005 are regarded as desirable materials from the practical point view. 3. Also, the effect on thermal energy reduction is largely affected by the method of thermal screen installation. The surrounding boundary of the silkworm rearing bed(type A) is the most desirable method to reduce the energy, which saves 56.6% of it. 4. In the practical application, NW60 and type A is considered to be the best combination of material and installation method. By this combination, the level of maximum heating load can be reduced at the rate of 43% for spring season and 40% for autumn season. 5. Another heating method, comparted heating, can be recommended to save the energy.

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Wise Use through establishing Conservation Area in Nakdong River Estuary (낙동강하구의 보전지역 설정을 통한 현명한 이용방안 모색)

  • Cha, Min-Jun;Kim, Seung-Hwan;Yi, Gi-Chul
    • Journal of Wetlands Research
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    • v.12 no.1
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    • pp.83-94
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    • 2010
  • Purpose of this study is to define the wise use of Nakdong River estuary based on the expert's survey aiming to identify the core conservation area, the buffering area and the transition area of the estuary. The boundary of the each area is determined by overlaying the expert's opinion of the conservation area, the Biotop conservation value evaluation carried out by Busan Metropolitan city and the designated legal boundary of conservation such as Cultural Reserve area and Wetland Reserve area. Then the concept for wise use of the core preservation area, the buffering area and the transition area is set by the discussion, brainstorming and several workshops. We believe this research leads the sustainable development in the area of the Nakdong River estuary and helps to minimize the conflict among the stakeholders.