• Title/Summary/Keyword: Roof-Top Basis

Search Result 9, Processing Time 0.023 seconds

Edge-Effect Reduction Technique to Compute the Backscattering from Randomly Rough Conducting Surfaces (거친 도체 표면 후방 산란 계산을 위한 모서리 효과 저감 기법)

  • Hwang, Ji-Hwan;Kweon, Soon-Koo;Oh, Yisok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.25 no.5
    • /
    • pp.585-591
    • /
    • 2014
  • An improved numerical scattering model with the 2-dimensional moment method including roof-top basis and a modified window-function to reduce edge-effect is presented in this study. The roof-top basis function is used to depict randomly positioned surface currents and increase an efficiency of the moment method. To reduce the edge-effect which occurs at the end of numerically generated surfaces, an enhanced window-function which is weighted by incident angle variable is proposed. To validate an proposed 2-dimensional scattering model and numerical analysis techniques for randomly rough surfaces, computational results are compared and analyzed to SPM(Small Perturbation Model) as well.

Selection of Green Roof Initiative Zone for Improving Adaptation Capability against Urban Heat Island (도시열섬 적응능력 제고를 위한 옥상녹화 중점지역 선정 방안)

  • Park, Eun-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.17 no.1
    • /
    • pp.135-146
    • /
    • 2014
  • The improvement of adaptation capability against heat island (ACHI) by greening buildings is considered as an important measure to cope with a climate change. This study aimed to select the most appropriate zones for green roof initiative in case study sites, Bucheon, Anyang, and Suwon Cities and to investigate the characteristics of buildings for greening to improve ACHI. Relative ACHI for each lot was estimated from 0 to -9, assuming that it decreases with the distance from green space and waterbody. Low adaptation capabilities were mostly shown in the old urban blocks with dense low-rise buildings and lack of green space. Three blocks with the lowest ACHIs were chosen as a green roof initiative zone in each city. They are largely residential areas including low-rise buildings such as single, multi-household houses, townhouses, 5 or lower story apartments and few are industrial areas crowded with small factory buildings. The areas of building roof available for greening are 8.8% within the selected zones in Bucheon City, 5.3% in Anyang City, and 4.9% in Suwon City. As it were, 25.2~41.7% of the roof top areas are available for greening in these zones. It means that roof top areas of $25,000{\sim}120,000m^2$ can be used for greening within the selected zones of $0.64{\sim}1.65km^2$ to improve ACHI. The approach and results of the study are significant to provide a logical basis and information on location, scale, effect, and target figure of greening as a measure to cope with climate change.

Frequency selective surface with gridded square-loop elements (격자 사각 루프 형태를 갖는 주파수 선택 반사기)

  • 고지환;음만석
    • Journal of the Korean Institute of Telematics and Electronics D
    • /
    • v.34D no.9
    • /
    • pp.7-14
    • /
    • 1997
  • A rigorous analysis method of electromagentic scattering from frequency selective surface with gridded square loop elements in case of oblique incident and arbitrary polarization is presented, which uses the roof-top subdomain basis function. The frequency response and polarization characteristics of the reflected wave and the transmitted wave for various widths of the grid and the conductor square loop, and for the various gaps between the grid and the conductor square loop, and for the various gaps between the grid and square loop is investigated. To confirm the validity of presented method, frequency selective surfaces with gridded square loop elements are fabricated with honeycomb structures, calculate dvalues for the frequency response of the reflected wave and the transmitted wave for arbitrary incident angle and polarization are compared with measured values.

  • PDF

Moment method analysis of the moreno directional coupler (모멘트법을 이용한 moreno 방향성 결합기 해석)

  • 박면주;전대인;안병철;남상욱
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.7
    • /
    • pp.1842-1849
    • /
    • 1996
  • This paper presents a full-wave, moment method analysis of a Moreno directional coupler with tow crossed-slots between two crossed rectangular waveguides. the overall structure is divided into several rectangular waveguides and cavities by the use of the equivalence principle to the complex slot regions. this enables a simple and efficient analysis involving the well-known retangular waveguide/cavity Green's functions. For a numerically efficient simulation, the roof-top basis expansion and line testing is used and an acceleration technique is applied to the series summation in the Green's functions. The numerical results are compared with the measurements to verify the correctness of the present analysis.

  • PDF

Analysis on the Generation Characteristics of the 1MW PV Plant in the Jeju Island (제주지역에 설치된 1MW 태양광발전소의 발전특성 분석)

  • Lee, Gae-Myoung;Hwang, Choong-Gu
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.64 no.5
    • /
    • pp.726-731
    • /
    • 2015
  • An 1 MW PV plant constructed at the Ara campus of Jeju National University in May 2012, which was the biggest roof-top PV plant in Korea and the biggest PV plant in Jeju Island at the time. In this paper the generation characteristics of the plant was analyzed on the basis of the data obtained during 2 years.

A Study on the Architectural Design Characteristics of the Plan and the Structure in Sudeok Temple's Daeung-Jean (건축설계 측면에서 본 수덕사 대웅전의 평면과 가구 특성에 관한 연구)

  • Kim, Do-Kyoung
    • Journal of architectural history
    • /
    • v.17 no.4
    • /
    • pp.97-112
    • /
    • 2008
  • In this study, I attempted to the architectural design characteristics of Daeung-Jeon in Sudeok Temple. For this purpose, After I set up several assumptions in the basis of the general characteristics of Korean wood architecture, and then, analyzed floor plan, structural formation and section sizes of structure and bracket members in relation to module and unit. As the results, the characteristics of the design process of plan and structure are follows. (1) 1 ja(尺), the unit applied to this building is measured $307.6{\sim}318.3mm$) and the average is 312.9mm (2) It is estimated that the floor plan designed on the basis of the top of columns. By the applied unit, every bay of the front side and the side is each designed by 15 ja and 8.5 ja. (3) The section is composed of piled members which have same section size. As basic module of section size called 'jae(재;材)', it is estimated at width 0.45 ja by height 0.75 ja. And as the secondary module, height between jae and is called 'gyoe(계;)' and it wes designed by three height size of 0.25 ja, 0.27 ja and 0.30 ja, (4) It is estimated that the section plan was designed by the order as follows. Firstly, the horizontal position of purlins wes decided on the basis of the intersection point of long and short rafters, and then the position and the section size of purlins and jangheyo(長舌) wes decided on the basis of the slope of roof and rafters. Secondly, going down from purlins, the members of structure composed of 'jae' and 'gyoe' was repeated. Lastly, for the purpose of linking the structure members located on the center line of adjacent purlins organically, the height of whaban(화반) was controlled.

  • PDF

A Study on the Fabrication and Characteristics of Snow Removal PV Module & System using Heating Film (발열 필름을 이용한 제설 기능 PV module & system 제작 및 특성평가)

  • Park, Eun Bee;Cho, Geun Yuoung;Cho, Sung Bae;Kim, Hyun Jun;Yu, Jeong Jae;Park, Chi Hong
    • Current Photovoltaic Research
    • /
    • v.4 no.4
    • /
    • pp.159-163
    • /
    • 2016
  • Piled snow upon PV module interferes with Photoelectric Effect process through photovoltaic directly. As a result of this phenomenon, its generation efficiencies keep decreasing or are stuck at zero power generating status. In addition, PV facilities have been installed on those places such as water surface, roof-top, and other isolated places, dealing with conditions of "Securing high REC weighted value", "Difficulty of securing land" and so forth. Through this study, we are able to actualize the function of heating over PV modules when it snows. We adopted laminating method through heating film and modules, guaranteeing warranty more than for 25 years. Also we are trying remote control systemically, not by hardware control, to run parallel with automatic driving and monitoring system which enable to control operation time, insolation, amount of snowfall automatically. We applied analysis of actual proof to both snow removal PV system and general PV power system, and these led to bear power consumption analysis while snow-removing, and its comparison after finishing the task as "One stone, two birds." In the long run, we could carry out economic analysis against snow removal system, and this helps to verify the most maximized control method for snow removal conditons on a basis of weather information. this study shall let prevent people from negligent accidents, and improve power generation problems as mentioned from the top. Ultimately, we expect to apply this system to heavy snowfall regions in winter season in spite of its limited system installaion in Korean territory, initially.

Economic Analyses on the Satellite Broadband Internet Services for High Speed Trains (고속철도에서의 위성 광대역 인터넷서비스 경제성 분석)

  • Ahn, Jae-Kyoung;Song, Mi-Ja
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.11B
    • /
    • pp.997-1004
    • /
    • 2006
  • There is a growing demand to access the broadband internet while on the very fast move. In order to meet these users needs, much research has been made for providing the broadband internet and HDTV services via satellite broadband internet systems even at top train speeds above 200km/h. In this paper, economic analyses on the satellite broadband internet services for KTX are to be reviewed. Broadband internet to trains in Europe are investigated, and Boeing cases for planes are also examined. In the first step, system configuration which is composed of a hub, terminals, satellite, and gap fillers for the tunnel areas has been proposed. A terminal includes a ultra-fast high gain antenna installed on the roof of the train, and APs inside the coaches. Secondly, cost estimation on the capital expenditures as well as operating expenditures has been performed in the proposed configuration. From the european and Boeing cases, demand and tariff are postulated, consequently, service revenues are derived on the scenario basis. Thirdly, estimated costs and derived revenues make up net present value and internal rate of return in each scenario. Finally, conclusions and contribution of this study are presented.

Dispersion of Standing Stones at Noseongsan(Mt.Noseong) and Aspect of the Stone Decorated Garden(Soo-suk Jeongwon) at Chongsuk-Sa(Chongsuk Buddhist Temple) in Nonsan City (논산 노성산(魯城山)의 입석(立石) 분포와 총석사(叢石寺) 수석(樹石)의 정원적 면모)

  • Rho, Jae Hyun;Huh, Joon;Jang, Il Young
    • Korean Journal of Heritage: History & Science
    • /
    • v.43 no.1
    • /
    • pp.160-189
    • /
    • 2010
  • This study has been designed to grasp the present situation, shapes and meaning of the standing stones and rock pillars in the whole area of Noseong Mountain Fortress in Nonsan City which have never been academically reported yet. Accordingly, the research was carried out to grasp the spatial identity of Noseong Mt. and Noseong Mountain Fortress and the dispersion of standing stones scattered around inside and outside Noseong Mountain Fortress, while the shapes and structural characteristics of stones were investigated and analyzed focusing on Chongsuk Temple, which was considered to have the highest density of standing stones and greatest values for preservation as a cultural property. In consideration of the reference to the 'Top Sa' (tower temple) at the 'Bul Woo Jo' (Article about Buddhism Houses) of 'Shinjoong Dongguk Yeoji Seungram', theoretical existence of the temple according to surveying investigation, and the excavation records of roof tile pieces with the name of 'Gwan Eum Temple', it is presumed that there had been a Buddhist sanctum inside the fortress and it could be connected to the carved letters, 'Chongsuk Temple'. According the observation survey, the 6th place of standing stones among many other places inside the fortress shows that Chongsuk Temple appears to have the strong characteristics of artificially constructed space in consideration of the size of trees and stones, the composite trend of tree and stone composition, and trace of the adjacent well and strand and the construction of stairway leading to the stone gate. Along with the constellation of the Big Dipper carved on a rock at the same space, the stones, on which the letters of 'Shinseonam', 'Chilseongam' and 'Daejangam' were carved, including 'Chongsuksa', and the carved statue of Buddha, which was assumed to be Avalokitesvara Guan Yin, have offered clue which make it possible to infer that the space was a space for Chilseong and Mountain god(Folk Belief) that had originated from the combination of Buddhism, Taoism and folk religion. According to the actual measurement of standing stones at Chonsuk Temple, it was identified that there were big differences in height among 24 stones in total, ranging from 402~29cm and the averaged distance between each stone appeared to be 23.6cm. And the shape of stones appeared to be standing or flat, and various stones such as mountain-like stones and Buddha-like stones were placed in a special arrangement or assorted arrangement, but the direction of the stones had a consistency pointing to the west. And comparing to the trace of construction of ZEN Landscape Garden well known in the country, the three flat stones except for the standing and shaped stones appeared to have the shape of meditation statue, which is the typical formational factors of a ZEN Landscape Garden, on the basis of formational technique of stones. Among them, the flat stone facing the Buddhist saint statue, was formed by way of symbolization of three-mountain stone, which was assumed to be an offering stone for sacrificial food rather than carrying out ZEN Meditation. In consideration of the formation of standing stones at Chong-suk Temple, which was carried out in the composite stoning method based using the scalene triangle with ratio of 3:5:7 in order to seek the in-depth beauty based on the stone statues of three Buddhas where the three factors such as heaven, earth and humans are embodied in the elevated or flat formation, the stones at Chongsuk Temple and the space seemed to the trace of contracted garden construction that was formed with stones for a temple, so that could be used for ZEN meditation.