• 제목/요약/키워드: Roofs

검색결과 329건 처리시간 0.027초

항공영상에서 건물지붕 검출을 위한 선소의 그룹화 기법 (Line segment grouping method for building roof detection in aerial images)

  • 예철수;임영재;양영규
    • 한국지형공간정보학회:학술대회논문집
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    • 한국지형공간정보학회 2002년도 추계학술대회
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    • pp.133-140
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    • 2002
  • 본 논문에서는 다양한 건물 지붕의 검출에 사용될 수 있는 선소의 그룹화 기법을 제안한다. 먼저 에지 보존 필터를 사용하여 영상에 포함된 잡음을 제거한 후에 watershed 기법을 이용하여 에지의 위치를 보존하고 영상 분할을 수행한다. 분할된 영역의 경계선에 위치한 화소들의 곡률을 계산하여 control point를 검출하고 control point 사이의 선소를 추출한다. 추출된 선소들의 방향과 길이를 고려하여 선소의 연결을 수행하고 최종적으로 화소의 그레디언트 크기를 이용하여 선소의 위치를 조정한다. 항공 영상에 제안한 방법을 적용하여 건물 지붕을 정확하게 검출할 수 있음을 보였다.

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건축물 외장재 열화현상에 영향을 미치는 자외선 발생량 추정 및 기후 맵 작성 (Assumption and Climate-Map Drawing of Ultra Violet Rays Influencing to the Deterioration of Building Exterior Materials)

  • 이정재
    • KIEAE Journal
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    • 제6권2호
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    • pp.19-26
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    • 2006
  • Recently, building requirements have been saturated and residents are demanding a variety of building exterior materials faced with roofs, walls, windows and doors. On the other hand, when building exterior materials are exposed with ultra violet rays during some periods, these will be influenced deterioration effects like discolorations, exfoliations and cracks and will be needed exchange of materials. In this study, main 17-provinces of Korea were collated climate data and counted the computation results with an assumption formula for calculating ultra violet rays amounts. Lastly, ultra violet rays map of Korea was made by the counted data and was considered tendencies. Accordingly, in the phase of design the designer can select the appropriate exterior materials which have durabilities and resistances of ultra violet rays. So hereafter this study can be a foundation study to sustain building exterior materials with ultra violet rays damages. Below is the summary of Korean ultra violet rays tendency. 1. Ultra violet rays during 1 year is from about $180MJ/m^2$ to about $210MJ/m^2$. 2. Southern province ultra violet rays is higher than northern province. 3. Annually counted rays is higher and higher.

식물뿌리의 생장특성을 고려한 패널형 방수공법의 조인트부 방근설계에 관한 실험적 연구 (A Experimental Study on the Root Barrier Design of Joint of Panel Type Waterproofing Method by Considering the Growth Diagnosis of Root)

  • 최성민;최수경;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2009년도 추계 학술논문 발표대회
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    • pp.183-189
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    • 2009
  • In this study, the growth diagnosis of root is analyzed through plant's auxanology point of view, and the inductive root barrier ability of panel type waterproofing method which is designed to deal with it, is confirmed positively through long term(2 years) mock-up test. Moreover, basic ideas for inductive root barrier design in joint is presented through this study. The experiment result for the root barrier of sealed A-type during 24 months, there were no damages found on the waterproofing layer. -urethane sealing material was used to apply for waterproofing of joint- for roots. As the result, it was confirmed that it is possible to maintain the root barrier of method through applying inductive root barrier design such as the installation of decreasing space of bearing power which considers the growth diagnosis of root, even if the root barrier was not secured.

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3-D characteristics of conical vortex around large-span flat roof by PIV technique

  • Sun, Huyue;Ye, Jihong
    • Wind and Structures
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    • 제22권6호
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    • pp.663-684
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    • 2016
  • Conical vortices generated at the corner regions of large-span flat roofs have been investigated by using the Particle Image Velocimetry (PIV) technique. Mean and instantaneous vector fields for velocity, vorticity, and streamlines were measured at three visual planes and for two different flow angles of $15^{\circ}$. The results indicated that conical vortices occur when the wind is not perpendicular to the front edge. The location of the leading edge corresponding to the negative peak vorticity and maximum turbulent kinetic energy was found at the center of the conical vortex. The wind pressure reaches the maximum near the leading edge roof corner, and a triangle of severe suctions zone appears downstream. The mean pressure in uniform flow is greater than that under turbulent flow condition, while a significant increase in the fluctuating wind pressure occurs in turbulent streams. From its emergence to stability, the shape of the vortex cross-section is nearly elliptical, with increasing area. The angle that forms between the vortex axis and the leading edge is much smaller in turbulent streams. The detailed flow structures and characteristics obtained through FLUENT simulation are in agreement with the experimental results. The three dimensional (3-D) structure of the conical vortices is clearly observed from the comprehensive arrangement of several visual planes, and the inner link was established between the vortex evolution process, vortex core position and pressure distribution.

Effects of dead loads on the static analysis of plates

  • Takabatake, Hideo
    • Structural Engineering and Mechanics
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    • 제42권6호
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    • pp.761-781
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    • 2012
  • The collapse of structures due to snow loads on roofs occurs frequently for steel structures and rarely for reinforced concrete structures. Since the most significant difference between these structures is related to their ability to handle dead loads, dead loads are believed to play an important part in the collapse of structures by snow loads. As such, the effect of dead loads on displacements and stress couples produced by live loads is presented for plates with different edge conditions. The governing equation of plates that takes into account the effect of dead loads is formulated by means of Hamilton's principle. The existence and effect of dead loads are proven by numerical calculations based on the Galerkin method. In addition, a closed-form solution for simply supported plates is proposed by solving, in approximate terms, the governing equation that includes the effect of dead loads, and this solution is then examined. The effect of dead loads on static live loads can be explained explicitly by means of this closed-form solution. A method that reflects the effects of dead loads on live loads is presented as an example. The present study investigates an additional factor in lightweight roof structural elements, which should be considered due to their recent development.

Wind loading on trees integrated with a building envelope

  • Aly, Aly Mousaad;Fossati, Fabio;Muggiasca, Sara;Argentini, Tommaso;Bitsuamlak, Girma;Franchi, Alberto;Longarini, Nicola;Crespi, Pietro;Chowdhury, Arindam Gan
    • Wind and Structures
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    • 제17권1호
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    • pp.69-85
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    • 2013
  • With the sustainability movement, vegetated building envelopes are gaining more popularity. This requires special wind effect investigations, both from sustainability and resiliency perspectives. The current paper focuses on wind load estimation on small- and full-scale trees used as part of green roofs and balconies. Small-scale wind load assessment was carried out using a wind tunnel testing in a global-effect study to understand the interference effects from surrounding structures. Full-scale trees were investigated at a large open-jet facility in a local-effect study to account for the wind-tree interaction. The effect of Reynolds number combined with shape change on the overall loads measured at the base of the trees (near the roots) has been investigated by testing at different model-scales and wind speeds. In addition, high-speed tests were conducted to examine the security of the trees in soil and to assess the effectiveness of a proposed structural mitigation system. Results of the current research show that at relatively high wind speeds the load coefficients tend to be reduced, limiting the wind loads on trees. No resonance or vortex shedding was visually observed.

Vulnerability model of an Australian high-set house subjected to cyclonic wind loading

  • Henderson, D.J.;Ginger, J.D.
    • Wind and Structures
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    • 제10권3호
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    • pp.269-285
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    • 2007
  • This paper assesses the damage to high-set rectangular-plan houses with low-pitch gable roofs (built in the 1960 and 70s in the northern parts of Australia) to wind speeds experienced in tropical cyclones. The study estimates the likely failure mode and percentage of failure for a representative proportion of houses with increasing wind speed. Structural reliability concepts are used to determine the levels of damage. The wind load and the component connection strengths are treated as random variables with log-normal distributions. These variables are derived from experiments, structural analysis, damage investigations and experience. This study also incorporates progressive failures and considers the inter-dependency between the structural components in the house, when estimating the types and percentages of the overall failures in the population of these houses. The progressively increasing percentage of houses being subjected to high internal pressures resulting from damage to the envelope is considered. Results from this study also compare favourably with levels of damage and related modes of failure for high-set houses observed in post-cyclone damage surveys.

고대(古代) 한국(韓國)·중국(中國) 건축관계사(建築關係史) 연구(硏究)(II) 백제(百濟)를 대상(對象)으로 (A Study on the History of Architectural Relationship in Ancient China and Korea (II) -On the Baegje Period-)

  • 이왕기
    • 건축역사연구
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    • 제3권1호
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    • pp.23-43
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    • 1994
  • In this study, it has compared and investigated the architecture of Six-Dynasty in China which was the same period of Baegje. There are no buildings to remain as a Baegje's architecture, but the architectural traces are remained. Especially, the architectural traces in Six-Dynasty are much left in cave temples. The reason to compare the architecture between China and Baegje intends to restore the Baegje's architectural style ultimately. The two countries, China and Baegje, were very close and they traded each other at that time. In the method of comparison, it has been investigated the form, the style and characteristics in each parts such as podium, column base, column, doors and windoors, brackets and roofs. As a result of the study, it has shown that the Baegje's architecture was not splendid compared to the architecture of Six-Dynasty. Baegje developed it's own architectural technique and used it only to the Baegje architecture. Since there was historical records that Baegje sent it's own architectural engineers to surrounding countries, Silla and Japan, it confirms that Baegje's architectural techniques were excellent. We need more time and constant research to restore the Baegje's architectural style ahead of time.

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Towards guidelines for design of loose-laid roof pavers for wind uplift

  • Mooneghi, Maryam Asghari;Irwin, Peter;Chowdhury, Arindam Gan
    • Wind and Structures
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    • 제22권2호
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    • pp.133-160
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    • 2016
  • Hurricanes are among the most costly natural hazards to impact buildings in coastal regions. Building roofs are designed using the wind load provisions of building codes and standards and, in the case of large buildings, wind tunnel tests. Wind permeable roof claddings like roof pavers are not well dealt with in many existing building codes and standards. The objective of this paper is to develop simple guidance in code format for design of loose-laid roof pavers. Large-scale experiments were performed to investigate the wind loading on concrete roof pavers on the flat roof of a low-rise building in Wall of Wind, a large-scale hurricane testing facility at Florida International University. They included wind blow-off tests and pressure measurements on the top and bottom surfaces of pavers. Based on the experimental results simplified guidelines are developed for design of loose-laid roof pavers against wind uplift. The guidelines are formatted so that use can be made of the existing information in codes and standards such as American Society of Civil Engineering (ASCE) 7-10 standard's pressure coefficients for components and cladding. The effects of the pavers' edge-gap to spacer height ratio and parapet height to building height ratio are included in the guidelines as adjustment factors.

초단열 슈퍼윈도우의 단열성능 실측과 시뮬레이션 비교 분석 (A Comparative strudy on the Insulation Performance of the Super Window by Actual Survey and Simulation)

  • 장철용;김치훈;안병립;홍원화
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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    • pp.231-235
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    • 2009
  • According to flow of energy, the loss occurs through walls, roofs, windows and so on. Among these case, most of the loss that is about 45% occurs through windows. windows's U-value is six times higher than wall's one according to Building code, so the loss through windows accounts for very much rates. Currently, Exterior wall's U-value about building envelope is 0.35~0.58W/ mK, but windows's one is 3.3W/ mK. It means that the loss through windows occupy very much amounts relatively. Therefore, the solution is required to reduce energy loss and increasing displeasure caused by excessive influx of solar energy through windows, to solve the problems Like decoloration on indoor furniture an clothes by harmful ultraviolet rays, air conditioning and increased cost. Therefore, on this paper, Thermal Performance was evaluated through actual test about high insulation Super Window which can improve thermal performance and the Simulation result was compared with actual resul by using Simulation program WINDOW and THERM.

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