• Title/Summary/Keyword: Dome part

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Enlargement of Extraspinal Cysts in Spinal Dysraphism : A Reason for Early Untethering

  • Kim, Kyung Hyun;Wang, Kyu-Chang;Lee, Ji Yeoun
    • Journal of Korean Neurosurgical Society
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    • v.63 no.3
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    • pp.342-345
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    • 2020
  • Some types of spinal dysraphism can be accompanied by extraspinal cysts, including myelomeningocele, myelocystocele, myelocele, meningocele, limited dorsal myeloschisis, lipomyelomeningocele, and terminal myelocystocele. Each disease is classified according to the developmental mechanism, embryologic process, site of occurrence, or internal structure of the extraspinal cyst. In most cystic spinal dysraphisms except meningocele, part of the spinal cord is attached to the cyst dome. Most open spinal dysraphisms pose a risk of infection and require urgent surgical intervention, but when the cyst is accompanied by closed spinal dysraphism, the timing of surgery may vary. However, if the extraspinal cyst grows, it aggravates tethering by pulling the tip of the cord, which is attached to the dome of the cyst. This causes neurological deficits, so urgent surgery is required to release the tethered cord.

Further Development of Vision-Based Strain Measurement Methods to Verify Finite Element Analyses

  • Kim, Hyung jong;Lee, Daeyong
    • Transactions of Materials Processing
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    • v.5 no.4
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    • pp.343-352
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    • 1996
  • One of the preferred methods that can be used to verify the results of finite element analysis is to measure surface strains of the deformed part for purpose of direct comparison with simulation results. Instead of using the usual manual method the vision-based measurement method is capable of determining surface geometry and strain from the deformed grid pattern automatically with the help of a computer. To obtain strain distribution over an area, the coordinates of such a surface grid are determined from the multiple video images by applying the photogrammetry principle. Methods to improve the overall accuracy of the vision-based strain measurement system are explored and the possible accuracies that can be attained by such a measurement method are discussed. A major emphasis is placed on the initial grid application method its accuracy and ease of subsequent image processing. Finite element analyses of limiting dome height(LDH) test are carried out and the results of them are compared with exsperimen-tal data.

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Study of Size Optimization for Skirt Structure of Composite Pressure Vessel (복합재 압력용기의 스커트 치수 최적화 설계 연구)

  • Kim, Jun Hwan;Shin, Kwang Bok;Hwang, Tae Kyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.1
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    • pp.31-37
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    • 2013
  • This study aims to find the optimal skirt dimensions for a composite pressure vessel with a separated dome part. The size optimization for the skirt structure of the composite pressure vessel was conducted using a sub-problem approximation method and batch processing codes programmed using ANSYS Parametric Design Language (APDL). The thickness and length of the skirt part were selected as design variables for the optimum analysis. The objective function and constraints were chosen as the weight and the displacement of the skirt part, respectively. The numerical results showed that the weight of the skirt of a composite pressure vessel with a separated dome part could be reduced by a maximum of 4.38% through size optimization analysis of the skirt structure.

Volcanisms and Volcanic Processes of the Wondong Caldera, Korea (원동 칼데라의 화산작용과 화산과정)

  • 황상구;이기동;김상욱;이재영;이윤종
    • The Journal of the Petrological Society of Korea
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    • v.6 no.2
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    • pp.96-110
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    • 1997
  • The Wondong Caldera, formed by the voluminous eruption of the rhyolitic ashflows of the Wondong Tuff which is about 1,550 m thick at the intracaldera and 550 m at the outflow, is a resurgent caldera which shows a dome structure on the central exposure of the caldera. The Wondong caldera volcanism eviscerated the magma chamber by a series of explosive eruptions during which rhyolitic magma was ejected, as small fallouts and voluminous ash-flows, to form the Wondong Tuff. The explosive eruptions began with ash-falls, progressed through pumice-falls and transmitted ash-flows. During the ash-flow phase the initial central vent eruption transmitted into late ring-fissure eruption which accompanied with caldera collapse. Contemporaneous collapse of the roop of the chamber resulted in the formation of the Wondong Caldera, a subcircular depression subsiding about 1,930 deep. Following the collapse, quartz porphyry was intruded as ring dykes along the ring fracture near the southwestern caldera rim. Subsequently the central part of the caldera floor began to be uplifted into a circular resurgent dome by the rising of residual magma. Concurrent with the resurgent doming, the volcaniclastic sediments of Hwajeri Formation were accumulated in the caldera moat and then rhyodacite lava erupted from the initial central resurgent dome and another ash-flow tuff from the northern ring fracture. After the sedimentation, the find-grained granodiorite was intruded as an arc along the eastern ring fracture of the caldera. Finally in the central part, the resurgent magma was emplaced as a hornblende biotite granite stock that formed the central dome.

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Study on Buckling-Characteristics of Single-Layer Latticed Domes subject to Initial Imperfection (I) (Part I In the case of Rigid-Joint) (단층래티스돔의 좌굴특성에 미치는 형상초기부정에 관한 연구 (I) (제I보 강접합의 경우))

  • 박정우;정환목;권영환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.68-73
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    • 1993
  • The geometrical initial imperfection is generally described that a dome digeresses from ideal shape. In actual domes the mode and amplitude for initial imperfection appear variously and affect buckling-strength sensitively. This study investigates the buckling characteristics of single-layer latticed domes with triangular network subjected to initial imperfection. Additionally, this study is to get the data that are to formulate the general equation taking initial imperfection into consideration.

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A study on the molding of dome shaped plastic parts embedded with electronic circuits (전자회로 일체형 돔 형상의 플라스틱 부품 성형에 관한 연구)

  • Seong, Gyeom-Son;Lee, Ho-Sang
    • Design & Manufacturing
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    • v.14 no.1
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    • pp.15-21
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    • 2020
  • Smart systems in different application areas such as automotive, medical and consumer electronics require a novel manufacturing method of electronic, optical and mechanical functions into products. Traditional methods including mechanical assembly, bonding of plastic and electronic circuit cause the problems in large size of products and complicated manufacturing processes. In this study, thermoforming and film insert molding were applied to fabricate a dome shaped plastic part embedded with electronic circuits. The deformation of patterns printed on PET film was predicted by thermoforming simulation using T-SIM, and the results were compared with those by experiment. In order to decrease spring-back after thermoforming, the Taguchi method of design of experiment was used. Through ANOVA analysis, it was found that mold temperature was the most dominant parameter for spring-back. By using flow analysis, gate design was performed to decrease injection pressure. During film insert molding, the wash-out of ink printed on film occurred for Polycarbonate. When the resin was changed to PMMA, the wash-out disappeared due to low melt temperature.

The Elasto-Plastic Buckling Analysis of Ball-Jointed Single Layer Latticed Domes considering the Characteristics of a Connector (적합부 특성을 고려한 볼 접합 단층 래터스 돔의 탄소성 좌굴해석)

  • Han, Sang-Eul;Kwon, Hyun-Jae;Kim, Jong-Bum
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2 s.8
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    • pp.91-99
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    • 2003
  • The purpose of this study is to analyze the characteristics of the connector having an influence on the elasto-plastic buckling load of ball-jointed single layer latticed domes. As an analytic model, domes are composed of tubular member elements, balls and connectors. The joint system of members in single layer latticed domes has influence on the buckling load. Therefore, in this paper, the variation of the elasto-plastic buckling load by effects of the connectors characteristics is analyzed. The structural behavior of the connector is investigated by following points: (1) the length of rigid zone, (2) looseness of screw and (3) the diameter of connector. In addition, the elasto-plastic buckling analysis is carried out through the variation of the connectors section of yielding part, and then the buckling mode of the dome is examined. As a result, it is emphasized that the characteristics of the connector have significant effects on the buckling load of latticed domes.

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A Study on the Geometrical Expression Shown in the Architecture of Guarino Guarini - Focusing on the Analysis of Spatial Form in Guarino Guarini's Church of San Lorenzo- (구아리노 구아리니 건축에 나타난 기하학적 표현에 관한 연구 - 그의 산 로렌쪼 성당의 공간형태 분석을 중심으로 -)

  • Han Myoung-Sik
    • Korean Institute of Interior Design Journal
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    • v.14 no.3 s.50
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    • pp.95-102
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    • 2005
  • Guarini's architectural contribution has simply focused on the dome structure that has been known to us; however, his geometric and spatial construction has been overlooked so far Through this study, it has been demonstrated that the dome structure was simply part of geometrical forms that Guarini wanted to express ultimately and it functioned as a geometrical element such as the network combined with the entire spatial structure. The purpose of this study is to reevaluate Guarini's architectural thought by means of investigating the ultimate principles of spatial composition appeared in the late Baroque architecture through the analysis of the principles of spatial composition and organized formal Idioms by Guarini's geometrical concepts. Besides, it has been assumed that such geometrical concepts by Guarini's mathematical proportion and his reiteration and change of diagrams could be clearly distinguished from the Classical geometry in the Renaissance and Guarini. suggested a way to create a new space through more active and amusing application and transformation. In this aspect, Guarini's principles of geometric composition will be one of the role models that need to be seriously reconsidered in chaotic reality of modern architecture.

Finite Element Analysis for Performance Evaluation of Type III Hydrogen Pressure Vessel for the Clean Tech Fuel Cell Vehicles (친환경 연료전지 자동차용 Type III 수소 압력용기의 구조성능 평가를 위한 유한 요소 해석)

  • Son, Dae-Sung;Chang, Seung-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.9
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    • pp.938-945
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    • 2012
  • To design and estimate material failures of Type III pressure vessels, which have excellent stability and performance, various modeling techniques have been introduced. This paper provided a hybrid modeling technique composed of ply-based modeling for a cylinder part and laminate-base modeling technique for a dome part for enhancing modeling efficiency. The ply-based modeling technique provided accurate ply stresses directly for predicting material failure, on the other hand, additional manipulations in stress calculations, which may cause some errors, were needed for the case of the laminate-based modeling technique. The ply stresses in fiber, transverse and in-plane shear directions were compared with the corresponding material strengths to predict material failure.