• 제목/요약/키워드: Connected surface

검색결과 627건 처리시간 0.025초

연결 정보가 없는 포인트 데이타로부터 특징선 추출 알고리즘 (Extraction of Feature Curves from Unorganized Points)

  • 김수균;김선정;김창헌
    • 한국정보과학회논문지:시스템및이론
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    • 제33권10호
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    • pp.768-776
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    • 2006
  • 연결 정보가 없는 포인트 데이타가 주어졌을 때, 본 논문은 MLS(moving least-squares) 근사화 기법을 이용하여 포인트 데이타에 대해 근사화된 표면을 생성한다. 근사화된 표면에서의 각 포인트에 대해 지역적인 곡률과 곡률 미분 값을 측정 한 후, 딜러니 삼각화(Delaunay tessellation)를 통해 이웃간의 정보를 생성하게 되고, 연결된 포인트들 간의 제로-클로싱(zero-crossing)을 측정하여 특징 포인트들을 추출하고, 곡률 방향으로 추출 된 포인트들을 연결한다. 본 방법은 기존의 메쉬 데이타에서 특징 선을 찾는 방법과 비슷한 복잡도를 갖는다. 몇 개의 포인트-샘플 된 모델에 대해 특징 선 추출을 수행하며, 곡률의 크기에 따라 특징선의 두께를 조절하고 포인트-스플릿팅 방법에 의해 렌더링 한다.

지열원 열펌프 시스템의 냉${\cdot}$난방 성능 평가 (Cooling and Heating Performance Evaluation of a GSHP System)

  • 손병후;조정식;신현준;안형준
    • 설비공학논문집
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    • 제17권1호
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    • pp.71-81
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    • 2005
  • The main objective of the present study is to investigate the performance characteristics of a ground-source heat pump(GSHP) system with a 130 m vertical and 62 mm nominal diameter U-tube ground heat exchanger. In order to evaluate the performance analysis, the ground-source heat pump connected to a test room with $90\;m^2$ floor area in the Korea Institute of Construction $Technology(37^{\circ}39'N,\;126^{\circ}48'E)$ was designed and constructed. This ground-source heat pump system mainly consisted of ground heat exchanger, indoor heat pumps and measuring devices. The cooling and heating loads of the test room were 5.5 and 7.2 kW at design conditions, respectively. The experimental results were obtained from July 2, 2003 to July 1, 2004. The cooling and heating performance coefficients of the system were determined from the measured data. The average cooling and heating COPs for the system were obtained to be 4.90 and 3.96, respectively. The temperature variations in ground and the ground heat exchanger pipe surface at different depths were also measured.

ANALYSIS OF THE OCEAN' AND ATMOSPHERE ROLES IN THEIR HEAT INTERACTION WITH USE OF SATELLITE AND VESSEL

  • Grankov, Alexander Georgievich;Mil'shin, Alexander Alexeevich;Krapivin, Vladimir Fedorovich;Golovachev, Sergey Petrovich
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.1001-1002
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    • 2006
  • Special problem emphasized by specialists in the field of analyzing the heat interchanges in the system ocean-atmosphere (SOA) is a necessity of determination of the near-surface atmospheric temperature, which can be only indirectly connected with characteristics of the SOA natural microwave radiation measured from satellites. That is why, the following dilemma is not obvious, but interesting and promised: what is better - to use the satellite methods for retrieving the partial parameters of the SOA or for analysis its state as a whole. To our opinion, this task is similar to the idea recognized by specialists engaged in the heat infrared region (8-12 mcm) of electromagnetic spectrum and its applications, where an intensity of natural infrared radiation (effective radiation) is used as the inherent property (the attribute) of the SOA heat balance. Here we studied important aspects of this problem: a) what medium initiates a heat transfer in the SOA and disturbs its heat balance - the ocean or the atmosphere b) what SOA parameters directly influence on its natural microwave radiation intensity (brightness temperature) measured from satellites? We relate these processes mainly to the synoptic range of time scales enriched by various events in the SOA interface such as the mid-latitude and tropical cyclones.

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일사열 배제를 위한 통기벽체 적정 길이에 대한 검토 (A Study on the optimal length of air cavity for Solar heat removal with Air-Vent System)

  • 김상진;금종수;최광환;신병환;정용현
    • 한국태양에너지학회 논문집
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    • 제24권2호
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    • pp.33-38
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    • 2004
  • Outside wall systems we lost much energy from the dew of thermal bridge and unsuitable adiabatic construction. The air vent wall system can make reduce cooling loads from the outside wall in summer. The basic concept is connected with buoyant force by the difference of density. An external surface of a wall absorbs solar radiation, and transfers it to the air in the cavity. The warmed air gets buoyant force. So the warmed air is released through the top opening and cooler outside air replaces the space in the cavity. So because of the cavity and the openings, the cooling load reduction by natural ventilation is believed to be considerable. The purpose of this study is finding optimal length of air cavity by numerical analyses.

PV모듈에서 그림자에 의한 전기적 특성 (The Electrical Characteristics of Shading Effect in Photovoltaic Module)

  • 김승태;강기환;박지홍;안형근;유권종;한득영
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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    • pp.257-262
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    • 2008
  • In this paper, we study the electric characteristics of shading effects in photovoltaic module in case of outdoor operation. When fabricating PV module, solar cells are connected serially to obtain the high voltage because of its low open circuit voltage. And total current is determined by lowest current among solar cells. When the shading happens on PV module's surface, the current of shaded solar cell determine the total current flow. Because of this, generally by-pass diode is installed on junction box. The bypass diode operate when revered and shaded solar cell's voltage is over 0.6 voltage. The reverse-biased solar cell gives reduced maximum power of PV module and might give negative effect on durability. So, adequate by-pass installation and selection is needed.

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유도탄 성능분석을 위한 실시간 병렬처리 시뮬레이터 연구 (Study on Real-time Parallel Processing Simulator for Performance Analysis of Missiles)

  • 김병문;정순기
    • 제어로봇시스템학회논문지
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    • 제11권1호
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    • pp.84-91
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    • 2005
  • In this paper, we describe the real-time parallel processing simulator developed for the use of performance analysis of rolling missiles. The real-time parallel processing simulator developed here consists of seeker emulator generating infrared image signal on aircraft, real-time computer, host computer, system unit, and actual equipments such as auto-pilot processor and seeker processor. Software is developed from mathematic models, 6 degree-of-freedom module, aerodynamic module which are resided in real-time computer, and graphic user interface program resided in host computer. The real-time computer consists of six TIC-40 processors connected in parallel. The seeker emulator is designed by using analog circuits coupled with mechanical equipments. The system unit provides interface function to match impedance between the components and processes very small electrical signals. Also real launch unit of missiles is interfaced to simulator through system unit. In order to apply the real-time parallel processing simulator to performance analysis equipment of rolling missiles it is essential to perform the performance verification test of simulator.

Laser-induced Damage to Polysilicon Microbridge Component

  • Zhou, Bing;He, Xuan;Li, Bingxuan;Liu, Hexiong;Peng, Kaifei
    • Current Optics and Photonics
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    • 제3권6호
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    • pp.502-509
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    • 2019
  • Based on the typical pixel structure and parameters of a polysilicon uncooled bolometer, the absorption rate of a polysilicon microbridge infrared detector for 10.6 ㎛ laser energy was calculated through the optical admittance method, and the thermal coupling model of a polysilicon microbridge component irradiated by far infrared laser was established based on theoretical formulas. Then a numerical simulation study was carried out by means of finite element analysis for the actual working environment. It was found that the maximum temperature and maximum stress of the microbridge component are approximately exponentially changing with the laser power of the irradiation respectively and that they increase monotonically. The highest temperature zone of the model is gradually spread by the two corners of the bridge surface that are not connected to the bridge legs, and the maximum stress acts on both sides of the junction of the microbridge legs and the substrate. The mechanism of laser-induced hard damage to polysilicon detectors is the melting damage caused by high temperature. This paper lays the foundation for the subsequent study of the interference mechanism of the laser on working state polysilicon detectors.

The Effects of Multiple Recycling on Deinkability and Properties of Recycled Paper

  • Shin, Jun-Seop;Cho, Hern-Joung
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
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    • pp.361-365
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    • 1999
  • This study examined the effects of multiple recycling on deinkability and properties of recycled paper from laser computer printout (LCPO). First, alkaline paper with a 20% printed area was disintegrated by TAPPI standard disintegrator at room temperature. After dewatering, the pulp was flotated and dried in oven at80$^{\circ}C$ for 24 hrs. A sequence of wetting, disintegrating, flotating and drying was one recycling cycle and this cyclic treatment was repeated from zero to five times. The recycled handsheet dropped to 90% of the original brightness after five cycles, and lost the most brightness after five cycles, and lost the most brightness in the first two cycles. However, it had a gain of 10% in opacity after five cycles as the same as the case of nonprinting. And, in this study, the method for determining residual ink(toner) content in recycled handsheets ere established by means of SEM-EDX and Py-GC. The change of residual ink percentage on recycled paper showed the effect of recycling numbers on deinkability of waste paper. A slight decrease in deinkability was noted for the recycled handsheets, which may be due to the change of fiber surface free energy connected with fiber swelling.

근대건축 형성기 영국과 독일의 건축이론 비교 연구 -러스킨과 무테지우스의 이론을 중심으로- (John Ruskin and Herman Muthesius - A Comparative Study on the Architectural Theories of the Early Modern Movements in Britain and Germany -)

  • 김봉열
    • 건축역사연구
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    • 제1권2호
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    • pp.116-136
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    • 1992
  • Architectural essence of John Ruskin's discourse can resolve itself into natural beauty, craftmanship, and truth in structure, surface, and process. His theories became disciplines of modern English school, Art and Craft and Free architecture, in aspects of organic architecture, morality, and rationality. These concepts disseminated continental Art Nouveau and also became it's basic principles. But his empirical theories hated use of machine, and should find a ideal model in medieval romanticism of Gothic. Anti-machine, as a instictive guideline of English modern architecture, couldn't cope with the industrialization of 20th century, and Gothic revival interfered with creating a new style. Muthesius' discourses were taught by the power of group movements and modern concept of form in English school, originally by Ruskin. But he accepted the potentiality of machine and mass production, and stressed creating the new German style suitable with machine. With the progress of Deutscher Werkbund, his theories were advanced to 'quality' connected with craftmanship, to discourse on mechanical 'form', and lastly to 'standardization and type' for mass production. Mechanical functionalism of Muthesius and DWB were sophiscated and handed down to Bauhaus, and then finally helped establishment of the Modern Architecture and Internationalism. Both English and German modern architecture owed their contribution as well as limitation to Ruskin and Muthesius as theorists. Through this comparative study, we can see the priority of theory to practice, the theoretical justification based on insight for its society and future, and the practical character of theory itself.

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조석효과에 의한 항구 모델 주위의 유동 및 물질전달에 관한 실험적 연구 (Experimental study on the fluid flow and material transport around a harbor driven by the tidal effect)

  • 서용권;문종춘;강종대
    • 한국해양공학회지
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    • 제10권1호
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    • pp.100-107
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    • 1996
  • In this paper, we report the results of the experimental study on the flow and the mass transport around a square harbor driven by a tidal effect. The model harbor is composed of a uniform water-depth with a straight breakwater. The harbor is connected to the outer ocean by an entrance region having the same shape as the harbor. We investigated two cases, one having another breakwater in the place between the entrance region and the outer ocean, and the other without it, The surface and bottom flow patterns of the model container are visualized by using light particles and dye, respectively. It was shown that the inner harbor and the entrance region have well-organized, large vortical residual flows, and the material transport between the entrance and outer region is however significantly different for two cases; when the breakwater is built between the two regions, the transport is far better than that without it, which is clearly contrary to our common sense that the breakwater would block the dispersion of the materials between the harbor and the outer ocean.

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