• Title/Summary/Keyword: cross sectional shape

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Experimental Study on Deformation Resistance Capacity of SY Permanent Steel Form for RC Beam and Girder under Casting Concrete (SY 비탈형 보 거푸집의 콘크리트 타설시 변형저항성능에 관한 실험적 연구)

  • Bae, Kyu-Woong;Shin, Sang-Min
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.605-615
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    • 2021
  • Recently, to shorten construction periods and reduce labor costs, the need for a corrugated beam form in the RC structure is being emphasized. The purpose of this study is to evaluate the deformation performance of SY Beam, a newly developed corrugated beam form work, during concrete casting. The standard cross-sectional shape of SY Beam was determined by modeling the deck structure of various thicknesses using the MIDAS GEN program. As a result, the cross-sectional dimensions of the SY Beam were determined to be 400mm and 450mm in width and height, respectively. A total of three SY Beam specimens were fabricated using steel plate thicknesses of 0.8, 1.0, and 1.2mm. The load conditions applied during casting concrete at the actual site are reflected. The vertical and horizontal displacements of the SY beam were measured during concrete casting. As a result, the vertical displacement showed a tendency to decrease as the thickness increased. Considering both vertical and horizontal displacement, the case with steel plate thickness of 1.2mm is the safest and most immediately applicable to the field. In the future, to secure manufacturability, constructability, and economics, the optimum steel plate thickness should be derived, and additional analysis and experimental studies for 1.05, 1.1, and 1.15mm are required.

A study of incisive canal using a cone beam computed tomography (cone beam형 전산화 단층촬영장치를 이용한 절치관의 연구)

  • Kim Gyu-Tae;Hwang Eui-Hwan;Lee Sang-Rae
    • Imaging Science in Dentistry
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    • v.34 no.1
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    • pp.7-12
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    • 2004
  • Purpose: To investigate the anatomical structure of the incisive canal radiographically by a cone beam computed tomography. Materials and Methods: 38 persons (male 26, female 12) were chosen to take images of maxillary anterior region in dental CT mode using a cone beam computed tomography. The tube voltage were 65, 67, and 70kVp, the tube current was 7 mA, and the exposure time was 13.3 seconds. The FH plane of each person was parallel to the floor. The images were analysed on the CRT display. Results: The mean length of incisive canal was 15.87 mm±2.92. The mean diameter at the side of palate and nasal fossa were 3.49 mm±0.76 and 3.89 mm± 1.06, respectively. In the cross-sectional shape of incisive canal, 50% were round, 34.2% were ovoid, and 15.8% were lobulated. 87% of incisive canal at the side of nasal fossa have one canal, 10.4% have two canals, and 2.6% have three canals, but these canals were merged into one canal in the middle portion of palate. The mean angles of the long axis of incisive canal and central incisor to the FH plane were 110.3°±6.96 and 117.45°±7.41, respectively. The angles of the long axis of incisive canal and central incisor to the FH plane were least correlated (r= 0.258). Conclusion : This experiment suggests that a cone beam computed radiography will be helpful in surgery or implantation on the maxillary incisive area.

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Infinite Elements for Analysis of Diffraction and Radiation Problems in the Vertical Plane (연직 2차원 회절 및 방사문제 해석을 위한 무한요소)

  • 박우선;이달수;오영민;정원무
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.4
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    • pp.235-243
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    • 1991
  • This paper is concerned with developing infinite elements which are applicable to wave diffraction and radiation problems in the vertical plane. The near need region surrounding the solid body is modeled using conventional finite elements. but the far fold region is represented using the infinite elements developed in this study. The shape functions for the infinite elements are derived from the analytical eigenseries solution of the scattered waves in the far field region. The system matrices of the elements are constructed by performing the integration in the infinite direction analytically to achieve computational efficiency. Numerical analysis is carried out for two floating bodies with different cross-sectional shapes to prove the efficiency and validity of the elements. Numerical experiments are also performed to determine the suitable location of the infinite elements which directly affect accuracy and efficiency of the solution.

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A Study on Body Silhouette Change by Wearing English Women's Upper Garments of the Late $19^{th}$ Century (19세기 후반 영국 여성복 상의 착용에 따른 인체 실루엣 변화)

  • Cha, Joo-Eun;Chun, Jong-Suk
    • The Research Journal of the Costume Culture
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    • v.19 no.6
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    • pp.1205-1220
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    • 2011
  • The purpose of this study is to verify the change of body posture by putting on the late $19^{th}$ century English women's bodice or waistcoat. This study analyzed the female somatotype which puts on upper garments of Victorian era with using 3D body scan technology. Two sets of $19^{th}$ century women's bodice and waistcoat patterns were developed with the $19^{th}$ century model size and those patterns were used for making the experimental garments. The fit of experimental garments was evaluated by the degree of change with posture and waist measurements. Three women with the same waist girth measurements with the model size were participated to the fitting test. The postural change was measured from cross-sectional body diagrams. The result of this study showed that the waist measurement of the late $19^{th}$ century English women's bodice and waistcoat pattern was smaller than the waist girth measurement. These garments compressed the midriff of the body and it made women's distinct body silhouette. The waist girth measurement of 1876 bodice pattern was 9.2cm smaller than presented model size. The subjects' waist girth measurements were shortened by 5.0~6.1cm after wearing the 1876 bodice garment. The waist girth measurement of 1880 waistcoat pattern was 7.1cm smaller than presented model size. The subjects' waist girth measurements were shortened by 2.7~3.7cm after wearing the 1880 waistcoat garment. The back side parts of their waist were compressed and their postures were changed. The neck and shoulders were moved forward after wearing the experimental garments. These results showed that body posture could be changed to "S" shape silhouette as wearing the late $19^{th}$ century English women's bodice or waistcoat.

Experimental Study on Failure Behavior of Steel Members and Elements under Very Low Load-Cycles (극저하중(極低荷重)사이클을 받는 강부재(鋼部材) 및 요소(要素)의 파괴거동(破壞擧動)에 관한 실험적(實驗的) 연구(硏究))

  • Park, Yeon Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.2
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    • pp.257-268
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    • 1994
  • An experimental study was carried out to elicit important factors causing cracks and rupture of steel members and their elements under imposed large repeated deformations, and of the quantitative relationships among the important physical factors leading to failure. Each of twenty-eight angles and nine thin-plates served as the specimen and was subjected to repeated axial load after undergoing inelastic buckling. Particular attention was paid to the effects of loading pattern, failure mode and cross-sectional shape on the very-low-cycle failure behavior under loading repetitions of the order of a few to twenty. The experimental results show that energy dissipation capacity depends heavily on the entire history of loading, the failure mode, the slenderness ratio and the width-to-thickness ratio. No simple quantitative relations were observed between the initiation of the visible cracks or rupture and the energy dissipation capacity. The maximum values of residual "net" strains are found to range from 25% to 40%, independent of the test parameters.

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Awareness of Breast Cancer Warning Signs and Screening Methods among Female Residents of Pokhara Valley, Nepal

  • Sathian, Brijesh;Nagaraja, Sharath Burugina;Banerjee, Indrajit;Sreedharan, Jayadevan;De, Asis;Roy, Bedanta;Rajesh, Elayedath;Senthilkumaran, Subramanian;Hussain, Syed Ather;Menezes, Ritesh George
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4723-4726
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    • 2014
  • Background: Breast cancer is the second most common cancer in the world and by far the most frequent cancer among women. Objective: The present study was undertaken to assess the awareness of breast cancer warning signs and screening methods among the women of Pokhara valley, Nepal. Materials and Methods: A cross-sectional questionnaire survey was carried out in a community setting with the female population. The questionnaire was administered in face-to-face interviews by trained research assistants. Results: Nepalese women demonstrated poor awareness of warning signs like a breast lump, lump under the armpit, bleeding or discharge from the nipple, pulling of the nipple, changes in the position of the nipple, nipple rash, redness of the breast skin, changes in the size of the breast or nipple, changes in the shape of the breast or nipple, pain in the breast or armpit, and dimpling of the breast skin. While 100% of nurses were aware about breast self-examination(BSE), mammography and warning signs of breast cancer. Levels of knowledge were significantly poorer in women with other occupations. Graduates were more aware about BSE, mammogram and warning signs of breast cancer compared to those with other educational levels. Conclusions: The findings indicated that the level of awareness of breast cancer, including knowledge of warning signs and BSE, is sub-optimal among Nepalese women.

Numerical Study on Heat Transfer Performance of PCHE With Supercritical CO2 as Working Fluid (초임계 이산화탄소를 작동유체로 하는 인쇄기판형 열교환기의 형상변수에 따른 전열성능 수치모사)

  • Jeon, Sang Woo;Ngo, Ich-long;Byon, Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.11
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    • pp.737-744
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    • 2016
  • The printed circuit heat exchanger (PCHE) is regarded as a promising candidate for advanced heat exchangers for the next-generation supercritical $CO_2$ power generation owing to its high compactness and rigid structure. In this study, an innovative type of PCHE, in which the channel sizes for the heat source fluid and heat sink fluid are different, is considered for analysis. The thermal performance of the PCHE, with supercritical $CO_2$ as the working fluid, is numerically analyzed. The results have shown that the thermal performance of the PCHE decreases monotonically when the channel size of either the heat source channel or the heat sink channel, because of the decreased flow velocity. On the other hand, the thermal performance of the PCHE is found to be almost independent of the spacing between the channels. In addition, it was found that the channel cross sectional shape has little effect on the thermal performance when the hydraulic diameter of the channel remains constant.

A Study on Flexural Rigidity of Two-row Overlap Pile Wall for Deep Excavation Support (대심도 굴착면 지지를 위한 2열 겹침말뚝의 휨 강성에 관한 연구)

  • Choi, Won-Hyuk;La, You-Sung;Kim, Bum-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.33-43
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    • 2018
  • Two-row Overlap Pile wall is a novel retaining wall system with high flexural rigidity and waterproofing for deep excavation support currently being developed in Korea. The Two-row Overlap Pile wall is constructed by making an overlap between consecutive four-axis (or two-axis) auger piles which themselves are overlapped and arranged in zigzag manner. In this study, the flexural rigidity of the Two-row Overlap Pile wall, including the effect of cross-sectional shape, was examined using both theoretical and numerical approaches. The results of investigation suggested that the Two-row Overlap Pile wall formed with two-row piles exhibit greatly higher flexural rigidity than conventional one-row pile walls such as Cast in place pile (CIP) and Secant pile wall (SPW), whereas the effect of overlap length between piles on the flexural rigidity is relatively minimal.

Sell-modeling of Cylindrical Object based on Generic Model for 3D Object Recognition (3 차원 물체 인식을 위한 보편적 지식기반 실린더형 물체 자가모델링 기법)

  • Baek, Kyeong-Keun;Park, Yeon-Chool;Park, Joon-Young;Lee, Suk-Han
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.210-214
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    • 2008
  • It is actually impossible to model and store all objects which exist in real home environment into robot's database in advance. To resolve this problem, this paper proposes new object modeling method that can be available for robot self-modeling, which is capable of estimating whole model's shape from partial surface data using Generic Model. And this whole produce is conducted to cylindrical objects like cup, bottles and cans which can be easily found at indoor environment. The detailed process is firstly we obtain cylinder's initial principle axis using points coordinates and normal vectors from object's surface after we separate cylindrical object from 3D image. This 3D image is obtained from 3D sensor. And second, we compensate errors in the principle axis repeatedly. Then finally, we do modeling whole cylindrical object using cross sectional principal axis and its radius To show the feasibility of the algorithm, We implemented it and evaluated its accuracy.

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The Determination of Critical Buckling Load Applied to Tapered Columns (일정변단면(一定變斷面) 장주(長柱)의 임계좌굴하중(臨界挫屈荷重)의 결정(決定))

  • Yu, Chul Soo;Sohn, Sung Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.1
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    • pp.93-101
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    • 1984
  • New formulas to determine the critical elastic buckling load of long tapered columns are given. This study is restricted to solid round or rectangular columns with fixed-free ends as often used in highway design. The exact solution of the differential equation of the deflection curve is expressed in terms of Bessel Function and the solution is numerically evaluated using Bisection method by computer. In the F.E.M analysis of columns under their own weight, the stability problem can be resulted in a eigen value problem of conservative system. Approximate solution by the F.E.M is evaluted numerically using Jacobi method and compared with exact solution of the prismatic column to increase the precision. In addition, critical buckling load of the tapered column for every shape factor and ratio of cross-sectional change (Diameter of bottom end/Diameter of upper end) was converted into a comparable expression to critical buckling load of the prismatic column.

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