• 제목/요약/키워드: Irregular Shaped

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Seismic behavior of steel truss reinforced concrete L-shaped columns under combined loading

  • Ning, Fan;Chen, Zongping;Zhou, Ji;Xu, Dingyi
    • Steel and Composite Structures
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    • 제43권2호
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    • pp.139-152
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    • 2022
  • Steel-reinforced concrete (SRC) L-shaped column is the vertical load-bearing member with high spatial adaptability. The seismic behavior of SRC L-shaped column is complex because of their irregular cross sections. In this study, the hysteretic performance of six steel truss reinforced concrete L-shaped columns specimens under the combined loading of compression, bending, shear, and torsion was tested. There were two parameters, i.e., the moment ratio of torsion to bending (γ) and the aspect ratio (column length-to-depth ratio (φ)). The failure process, torsion-displacement hysteresis curves, and bending-displacement hysteresis curves of specimens were obtained, and the failure patterns, hysteresis curves, rigidity degradation, ductility, and energy dissipation were analyzed. The experimental research indicates that the failure mode of the specimen changes from bending failure to bending-shear failure and finally bending-torsion failure with the increase of γ. The torsion-displacement hysteresis curves were pinched in the middle, formed a slip platform, and the phenomenon of "load drop" occurred after the peak load. The bending-displacement hysteresis curves were plump, which shows that the bending capacity of the specimen is better than torsion capacity. The results show that the steel truss reinforced concrete L-shaped columns have good collapse resistance, and the ultimate interstory drift ratio more than that of the Chinese Code of Seismic Design of Building (GB50011-2014), which is sufficient. The average value of displacement ductility coefficient is larger than rotation angle ductility coefficient, indicating that the specimen has a better bending deformation resistance. The specimen that has a more regular section with a small φ has better potential to bear bending moment and torsion evenly and consume more energy under a combined action.

단순화 이선원 모델을 이용한 전자선 선량율 계산 알고리듬에 관한 예비적 연구 (A Feasibility study on the Simplified Two Source Model for Relative Electron Output Factor of Irregular Block Shape)

  • 고영은;이병용;조병철;안승도;김종훈;이상욱;최은경
    • 한국의학물리학회지:의학물리
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    • 제13권1호
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    • pp.21-26
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    • 2002
  • 블록을 사용한 부정형 전자선 조사면에서의 선량율(relative output factor, ROF)을 계산하는 전자선 알고리듬을 개발하고, 측정값과 계산값을 비교하여 알고리듬을 평가하였다. 전자선의 선량은 산란판, 전자선 cone 등 모든 요소를 고려한 1차선 부분과 블럭에 의한 2차선의 합으로 표시할 수 있다고 가정하였으며, 1차선은 가우스 분포를, 2차선은 거리역제곱 법칙만을 따른다고 가정하였다. 2차선 블럭 산란에 의한 각 분포는 고려하지 않았다. 이런 방법으로 전자선의 ROF를 유효 SSD, 1차선 분포 표준편차, 2차선 발생율 등 3가지의 인자만을 이용하여 선량율을 계산할 수 있는 단순한 방식을 고안하였다. 6, 9, 12, 16, 20 MeV의 전자선을 사용하여 이 모델을 검증하였다. 측정은 항상 개방 조사면의 선량 최대지점 깊이에서 실시하였으며 다양한 정사각형 치료면 측정으로 3개의 인자를 구할 수 있었다 직사각형 조사면과 부정형 조사면에 대하여 이 모델을 이용한 계산값과 측정값의 차이는 평균 1.0%이내였으며, 최대 2.1%를 넘지 않았다. 본 연구에서 개발한 알고리듬은 필요한 인자가 3개이면서 매 전자선 콘마다 5∼6회 측정으로 구할 수 있어서 임상 적용에 편리하며, 계산 결과가 정확하여 특이 오차를 보이는 유형에 관한 보완 연구를 수행하면 임상에 사용할 수 있음을 보였다.

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상피모양육종의 압착도말 세포학적 소견 -1예 보고- (Imprint Cytologic Features of Epithelioid Sarcoma -A Case Report-)

  • 최준혁;심영란
    • 대한세포병리학회지
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    • 제15권1호
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    • pp.65-69
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    • 2004
  • Epithelioid sarcoma is a malignant soft tissue neoplasm with an uncertain histogenesis. We report the imprint cytologic features of epithelioid sarcoma in the left shoulder of a 29-year-old male patient. Imprint cytologic findings showed dissociated and loose aggregates of anaplastic epithelioid cells on the necrotic, bloody, and inflammatory background. Tumor cells were round to polygonal shaped. Tumor cells had vesicular nuclei with abundant cytoplasm. The nuclei were irregular in shape and often eccentrically located. Some tumor cells were oval to spindle shaped. Binucleated and multinucleated cells were found. Intracytoplasmic vacuoles were present. On immunohistochemical stain, the tumor cells were positive for epithelial membrane antigen, vimentin, and CD34.

시츄견에서 다발성 피지선종과 항문주위선종의 혼합 발생 (Multiple Sebaceous Gland Adenoma and Perianal Gland Adenoma in a Shih Tzu Dog)

  • 강상철;양형석;정종태;한동균;배종희;김재훈
    • 한국임상수의학회지
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    • 제21권2호
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    • pp.187-190
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    • 2004
  • A mixed case of multiple sebaceous gland adenoma and perianal gland adenoma was found in a 11-year-old male Shih Tzu dog. Grossly, many masses less than 1 cm in diameter of back skin and single red-brown mass about 0.5 cm in diameter of inner ear were noted. In addition one of light-pink mass 5 cm in diameter was presented in the anus. All of the masses were well demarcated and dome-shaped or papillated nodules. Histologically, the mass from back and ear were composed with multiple irregular shaped or sized lobules of sebaceous glands. Masses were containing mostly mature sebaceous cells and multifocal cystic degeneration with acellular and bright eosinophilic materials. And the mass from peri-anal area was well-circumscribed and composed of broad, anastomosing trabeculae of well-differentiated hepatoid cells. There were very low mitotic figures in all masses. Based on these results, this case was diagnosed as the multiple sebaceous gland adenoma and perianal gland adenoma.

급속응고 분말법으로 제조한 Al-Zn-Mg-Zr-Mn-Cu합금의 시효특성 (The Aging Characteristics of an RS-P/M Al-Zn-Mg- Zr-Mn-Cu Alloy)

  • 이갑호
    • 한국분말재료학회지
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    • 제4권2호
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    • pp.100-105
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    • 1997
  • In this study the changes of the hardness and microstructures during aging at 120$^{\cire}C$ of an RS-P/M Al-5.6wt%Zn-2.0wt%Mg-1.3wt%Zr-1.0wt%Mn-0.25wt%Cu alloy were studied using a transmission electron microscopy. The hardness increased rapidly at early stage of aging and reached the maximun when the specimen was aged for 24 hr. The many irregular-shaped $Al_4Mn$ and rod-shaped $Al_6Mn$ dispersoids with 0.1-0.4 $\mu$m in length were observed in the as-extruded alloy. The dark particles with 2-3 nm in size were observed in aged specimen for 5hr and those are thought to be G.P.zones or precursor of $\eta'$ precipitates. In aged specimen for 24 hr, the $\eta'$ phases were distributed homogeneously within the matrix and the PFZ with 30-40 nm in width was observed along the grain boundary. With further aging, the width of PFZ increased and $\eta$ phases were also detected within the matrix.

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사각재 인발 공정의 코너채움에 관한 연구 (A Study on the Corner Filling in the Drawing of the Rectangular Rod)

  • 김용철;김영식;김병민
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 압출 및 인발 심포지엄
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    • pp.56-59
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    • 1999
  • In the present study, in order to investigate the effect of the corner filling in the drawing of the rectangular rod from a round bar, the drawing of the square rod from a round bar has been simulated by using rigid-plastic finite element method and artificial neural network has been introduced to reduce the number of simulation. The experimental investigation has been also implemented to verify the efficiency of the application of results of present and previous study. According to the results of present and pervious study, the combination of semi-die angle gives a great effect on the corner filling in case of the irregular shaped drawing process, but, in case of the regular shaped drawing process, the main process variable on the corner filling is reduction in area.

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소화물 일관수송업(택배업)의 경쟁력 강화 (Competitiveness of the Small Package Express Service)

  • 송계의
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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    • pp.223-238
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    • 1998
  • In this study, to investigate the effect of process variables such as reduction in area, semi-die angle and the rectangular ratio to the corner filling which influences the dimensional accuracy of the final product in the drawing of the cluadrangle rod from a round bar, it has been simulated by three dimensional rigid-plastic finite element method. In order to reduce the number of simulation artificial neural network has been introduced. Also, through the experimental investigation, the present results have been implemented on the industrial product. In results, the main process variable is the combination of the semi-die angle in case of the irregular shaped drawing process and reduction in area in the event of regular shaped drawing process, respectively.

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인삼배유세포에 존재하는 단백질체의 분해양상 (The Degrading Patterns of Protein Bodies in the Ginseng Endosperm Cells)

  • 이창섭;김우갑
    • Applied Microscopy
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    • 제24권4호
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    • pp.86-97
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    • 1994
  • Protein bodies in the endosperm cells of mature red ginseng (Panax ginseng C.A. Meyer) were distributed evenly in the cytoplasm and their size varied from 1 to $8{\mu}m$. Three types of protein bodies were detected and they are spherical or egg-shaped ones containing homogeneous matrix only, spherical ones containing globoids, and irregular shaped ones. Protein bodies degraded in two patterns, one is to start the degration of the body from the surface toward the center, while the other is that the body was broken evenly and then degraded gradually. After degradation, only the limiting membrane remained, that causes the body to be empty. The limiting membranes fused with each other to form a large vacuole. Vicilin and legumin decreased in the endosperm cells as the protein bodies degraded gradually whereas they increased in the umbiliform layers.

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사각재 인발 공정에서 코너 채움에 관한 유한 요소 해석 및 실험 (Finite Element Simulation and Experimental Investigation on the Corner Filling in the Drawing of Quadrangle Rod from a Round Bar)

  • 김용철
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.99-102
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    • 1999
  • In this study, to investigate the effect of process variables such as reduction in area, semi-die angle and the rectangular ratio to the corner filling which influences the dimensional accuracy of the final product in the drawing of the cluadrangle rod from a round bar, it has been simulated by three dimensional rigid-plastic finite element method. In order to reduce the number of simulation artificial neural network has been introduced. Also, through the experimental investigation, the present results have been implemented on the industrial product. In results, the main process variable is the combination of the semi-die angle in case of the irregular shaped drawing process and reduction in area in the event of regular shaped drawing process, respectively.

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Grovesinia moricola occurring on Parthenocissus tricuspidata

  • Shin, Hyeon-Dong;Choi, Young-Joon;Hong, Sun-Hee;Lee, Yong-Ho
    • 한국균학회지
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    • 제47권3호
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    • pp.271-274
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    • 2019
  • Between August and September 2017, zonate leaf spots with severe defoliation were observed on Parthenocissus tricuspidata in Gimcheon, Korea. The initial symptoms included water-soaked, gray to grayish brown, circular or irregular-shaped leaf spots. As the disease progressed, the spots enlarged, coalesced, and became cream-colored with characteristic target-shaped rings, leading to leaf blight and premature defoliation. Based on cultural and morphological characteristics, the fungus associated with the symptoms was identified as Grovesinia moricola. The identity of this fungus was confirmed by analyzing sequences of the internal transcribed spacer region of ribosomal DNA. The pathogenicity of the isolate was demonstrated by artificial inoculation. To our knowledge, this is the first report of G. moricola occurring on P. tricuspidata globally as well as in Korea.