• 제목/요약/키워드: Half-open angle

검색결과 14건 처리시간 0.018초

Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator

  • Zabihzadeh, Mansour;Birgani, Mohammad Javad Tahmasebi;Hoseini-Ghahfarokhi, Mojtaba;Arvandi, Sholeh;Hoseini, Seyed Mohammad;Fadaei, Mahbube
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.1685-1689
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    • 2016
  • Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended.

단위부재 모델화에 따른 단층 래티스 돔의 탄소성 좌골하중의 산정에 관한 연구 (A Study on the Estimation of Elasto-Plastic Buckling Loads for Sing1e Layer Latticed Domes by Unit Member Modeling Technique.)

  • 한상을;이상주;유용주;이경수
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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    • pp.290-297
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    • 1998
  • In this paper, we propose to a method to estimate the elasto-plastic buckling for single layer latticed domes. First, we assume that each member consists of the rigid zone and elastic spring at both end joint, the elastic element and three elasto-plastic spring to judge for yeilding the member. Next, the member which has most influence on buckling for structures is determined by a distributed pattern of the strain energy which is calculated through linear eigenvalue analysis. And then, normalized slenderness ratio of the element is derived considering the axial force at elastic buckling load. Later, we execute elasto-plastic nonlinear analysis that based on loading increasement method and displacement increasement method. From this results, we discusses the effect of the joint rigidity and the half open angle $\theta$$_{0}$ on the buckling strength of single layer lattice domes ; (1) how the joint rigidity contributes to the reduction of buckling loads, (2) how the reduction can be interrelated to compressive strength curves in terms of the generalized slenderness for the member most relevant to the overall buckling of domes.s.

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단층 래티스돔의 안정해석기법 및 좌굴특성에 관한 연구 (A Study on the Analytical Technique of Stability and Buckling Characteristics of the Single Layer Latticed Domes)

  • 한상을
    • 전산구조공학
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    • 제9권3호
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    • pp.209-216
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    • 1996
  • 본 논문의 목적은 단층래티스 돔의 안정해석 기법을 제안하고, 다양한 조건하에서 단층 래티스 돔이 갖는 좌굴특성을 규명하는데 있다. 기하학적 비선형 평형경로의 탐색 및 좌굴점 그리고 분기경로의 방향 등을 수직적으로 계산하기 위하여 호장법(Arc-Length Method)을 이용하였으며, 부재의 좌굴가능성을 판단하기 위하여 에너지밀도함수를 제안하였다. 강절점을 갖는 구조물의 거동 특성을 규명하기 위하여 3종류의 비선형 강성행렬을 유도하여 해석하였으며, semi-rigid절점을 갖는 구조물을 해석하기 위하여 스프링모델을 제안하고, 부재의 세장비, 반개각, 경계조건 및 다양한 하중조건을 파라메터로하여 좌굴특성을 규명하였다.

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고려시대 인물관련 제작물을 통해서 본 복식제도에 관한 연구(2)-고려시대 인물관련 제작 불화(佛畵)중 '경판화'를 통해서 본 복식제도에 관한 연구(2)-$\cicled3$- (A Study On the costume of the Koryo Dynasty (2)-$\cicled3$-See Through by the Human being, on the Buddist Painting of Koryo Dynasty Engraved Painting on the wood.-)

  • 임명미
    • 복식
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    • 제26권
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    • pp.221-232
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    • 1995
  • It was aimed to study the costume of Koryo dynasty based upon the one hundred and thirty four pictures of the engraved painting on the wood. The costume to study were made about 400 years during the King Mok-jong(1006) to the forth year of the king Wu based upon the Avatamaka Sutra and Pulsul-Yaesu 가) Men's wear 1. Hair style and hair dress ; Man tied up a top knot and they put on the hat such as a Kuan, Kun, and Mo. The young boys binds his hair up one, two, and three knots. 2. Clothes : 1) King wore an uniform of Mien-lu Kuan system. 2) The Crown Prince and high rank officials wore Yuan-yu-Kuan Won-jung-po-ju-Kuan, Sa-bang-Kuan, Yun-wha-Kuan and montain shape Po-ju-Kuan as a court dress. 3) Officials put on the Pok-du as an official dress and Won-jung-ip-mo, Kun and Mo as an everyday dress, the monk put on the diamond shape Do-kuan and Du-kun and the soldier put on the Helmet. Costume system of man was as follows ; They wore exchanged shape collar, big sleeve jacket, long skirt, apron, hanging precious stone big belt as a Mien-pok. 4) The soldiers wore helmet, Keun-Kap, Scarf, Pee-Bak, Hung-Kap, Pok-Kap, Yang-Dang-Kap, We-Yo-Kap, Kum-Kap, and caries arms. Lower-level officials wore Pe-Bal, Kun-Mo, gae, won-leung, very small sleve jacket, a long coat reaching up to the knee length, slacks, belt, loin cloth and apron. 5) Children's bind their hair up angle shape and wore a half long jacket raching up to the hip and slacks. 나) Women's wear; 1. hair style and hair dress; 1) High rank women's hair style was very extravaganceful. They made their hair top knot (one, two, or more knots) and decoraed precious stone, pan shape head dress, wheel shape head dress, and flower shape precious stone decorated head dress. 2. Clothes ; 1) High rank ladi's wore Kun-Kyun attached jacket, and jacket sleeves decorated pleats, and pleats decorated long skirt, apron, back apron, knot belt, scarf, this type is the same with Dang Dynasty, five dynasty of china, Song, Kum, Won, Myung Dynasty, and our costume of Poe-hae, and Shilla Dyansty. 2) Official ladies wore exchange shape collor, big sleeve jacket, long pleats skirt, apron, and back apron, scarf. 3) Women wore top knot hair style and decorated by ribbons. Shoulder scarf attached small sleeve jacket and wore reaching up to the knee length. Side seam is open and under wear was long skirt. 4) High knot hair style and exchanged shape collor jacket, under wear wore long skirt. They wore under skirts and the jackets. 5) High knot hair style, exchange shape collor jacket reaching up to the knee length small sleeve under wear wore long skirt, belt. 6) High knot hair style, big sleeve jacket and long skirt. 7) Foot wear wore boots, mokasin type shoes, sandal.

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