• 제목/요약/키워드: section shape

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The external and internal morphological standard of original plants and herbal states in 2 kind of Arisaematis Rhizoma (2종 천남성(天南星)의 외부(外部) 및 내부형태(內部形態)에 대한 연구)

  • Kim, Hong-Jun;Yun, Ju-Bong;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
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    • 제12권2호통권17호
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    • pp.63-73
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    • 2006
  • In the original plant of Arisaematis Rhizomas, the features of external and internal shape of Arisaema amurense var. serratum $N_{AKAI}$ and A. amurense $_{MAXIM}$. are as follows. 1. In the external shape of original plant, Arisaema amurense var. serratum $N_{AKAI}$ has high stem, an oval-elliptic leaflet and a serrate leaf margin. But A. amurense $M_{AXIM}$ has a relatively low stem, an upside oval leaflet and no serrate leaf margin. 2. On the herbs character of original plant, Ansaema amurense var. serratum $N_{AKAI}$ is small in height and diameter, but A. amurense $M_{AXIM}$ is relatively large in height and diameter. 3. On the gathered herbs character of original plant, the section of Arisaema amurense var. serratum $N_{AKAI}$ is brightly white, easily spilt and strong scent. But the section of A. amurense $M_{AXIM}$ is thin yellowish brown, not easily spilt and weak scent. Also the grade of gathered herbs, both can be classified by diameter and external scent. 4. In the current herbs character, Korean and Sichuan Province products are irregullar shape and have no scent, Jilin Province products are regular shape. Also, Guangxi Province products are small size and concave in one side, Hebei Province products are irregular size and shape. 5. In internal shape of original plant, epidermal cell of Arisaema amurense var. serratum is very tight. With the except of micro difference in parenchyma cell of cortex, on the whole there are nearly no differences with A. amurense $M_{AXIM}$. Also, samely in the internal shape, according to collecting sites, epidermis exhibits a lot layer in curving state and secreting duct is developed and vascular bundle and exists between parenchyma cell of cortex. In the future, additional study is needed to distinguish herb and effect between same genus-degree of relatedness.

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Blank Design in Sheet Metal forming Process Using the Rollback Method (롤백방법을 이용한 박판금속성형공정에서의 블랭크 설계)

  • 김종엽;김낙수;허만성
    • Transactions of Materials Processing
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    • 제8권5호
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    • pp.454-464
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    • 1999
  • A new blank design method is proposed to predict the optimum initial blank shape in the sheet metal forming process. The rollback method for blank shape design takes the difference between the deformed blank contour and the target contour shape into account. the minimization object function R is proposed. Based on the method, a computer program composed of blank design module, FE-analysis module and mesh generation module is developed. The rollback method is applied to square cup, reentrant cross section, L-shaped cup drawing process with the flange of uniform size around its periphery to confirm its validity. The optimum initial blank shape is obtained from an arbitrary blank shape after several modifications. Good agreements are recognized between the numerical results and the published experimental results for initial blank shape and thickness strain distribution. It is concluded that the rollback method is an effective and convenient method for an optimum blank shape design.

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Evaluation of Axial Behavior of Columns Strengthened with Different Transverse Reinforcements in Jacket Section (확대단면에서의 띠철근 배근 방법에 따른 보강 기둥의 중심 축하중 거동 평가)

  • Hwang, Yong-Ha;Yang, Keun-Hyeok;Sim, Jae-Il;Choi, Yong-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • 제22권6호
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    • pp.81-88
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    • 2018
  • The present study evaluated the effective arrangement approach of transverse reinforcement in the jacket section for seismic strengthening of reinforced concrete columns. To simulate the full-scale columns, the section dimensions were determined as $450{\times}450mm$ for non-seismic existing columns and $750{\times}750mm$ for section enlargement strengthening columns. Over-lapped channel-shape bars and prefabricated bar units were proposed for closed-hoops in the jacket section, and conventional cross-ties anchored into existing columns and V-ties were considered for the supplementary ties. Test results showed that the axial capacity of the existing column and section enlargement columns with over-lapped channel-shape hoops was similar to the nominal strength calculated using ACI 318-14 procedure whereas the section enlargement column with prefabricated bar units possessed 1.25 times higher axial capacity than the nominal prediction. Furthermore, the axial ductility ratio of the section enlargement column with prefabricated bar unit was 139% higher than that of the existing column despite the potential size effect on ductility of concrete. Thus, it can be concluded that the developed prefabricated bar unit technique is practically useful for preventing the premature buckling of longitudinal reinforcement and confining core concrete in the section enlargement strengthening columns.

Determination of Structural Member Section based on Nonlinear Behaviors of Steel Cable-Stayed Bridges and Harmony Search Algorithm (강사장교 비선형거동과 하모니 서치 알고리즘에 기반한 사장교 구성 단면 결정)

  • Sang-Soo Ma;Tae-Yun Kwon;Won-Hong Lee;Jin-Hee Ahn
    • Journal of the Korea institute for structural maintenance and inspection
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    • 제28권4호
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    • pp.1-12
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    • 2024
  • In this study, a determination method of structural member section based on Nonlinear behaviors of steel cable-stayed bridges and the Harmony Search algorithm was presented. The Harmony Search algorithm determines the structural member section of cable-stayed bridges by repeating the process of setting the initial value, initializing the harmony memory, configuring the new harmony memory, and updating the harmony memory to search for the optimal value. The nonlinear initial shape analysis of a three-dimensional steel cable-stayed bridge was performed with the cross-section of the main member selected by the Harmony Search algorithm, and the optimal cross-section of the main members of the cable-stayed bridge, such as pylons, girders, cross-beams, and cables, reflecting the complex behavior characteristics and the nonlinearity of each member was determined in consideration of the initial tension and shape. The total weight was used as the objective function for determining the cross-section of the main member of the cable-stayed bridges, and the load resistance ability and serviceability based on the ultimate state design method were used as the restraint conditions. The width and height ratio of the girder and cross-section were considered additional restraint conditions. The optimal sections of the main members were made possible to be determined by considering the geometry and material nonlinearity of the pylons, girders, and cross-sections and the nonlinearity of the cable members. As a result of determining the optimal cross-section, it was confirmed that the proposed analysis method can determine the optimal cross-section according to the various constraint conditions of the cable-stayed bridge, and the structural member section of the cable-stayed bridge considering the nonlinearity can be determined through the Harmony Search algorithm.

Fundamental Studies on the Net-Shape of the Drag Net-II On the Section Shape of the Simplified Model of the Bag Net in Four-Point Suspension (저예망의 어구형상에 관한 기초적 연구-II 단순화모형에 의한 4폭짜리 자루그물의 단면형상)

  • Lee, Ju-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • 제20권2호
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    • pp.65-71
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    • 1984
  • As a primary step in studying the relationship between the arrangement of netting and the section shape of the bag net in the four-seam trawling net, a series of experiments were performed with the simplified model of the bag net made of vinyl film. This model was suspended horizontally in circularly flowing water, with two pairs of suspending threads to four points of symetry at the border of the bag mouth in place of both wing nets. And then, the area distribution of each panel in the bag net was arranged by the portion of the length of the side panel, q to that of the lower or upper panel, p at the border of bag mouth. In the experiments, the section shape of the bag mouth photographed and the tensions on both pairs of suspending threads were measured with two loadcells in circularly flowing water. From the results that the section shape of the bag mouth in circularly flowing water is controlled by the area distribution of panels in the bag net, the author estimated an experimental equation. h/w=k sub(1) e super(k) 2 super(q/p)+C, where h is the central height of the bag mouth, and w is the lateral width of that.

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The Standardization of Developing Method of 3-D Upper Front Shell of Men in Twenties (20대 성인 남성 상반신앞판현상의 평면 전개를 위한 표준화 연구)

  • Cui, Ming-Hai;Choi, Young-Lim;Nam, Yun-Ja;Choi, Kueng-Mi
    • Fashion & Textile Research Journal
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    • 제9권4호
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    • pp.418-424
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    • 2007
  • The purpose of this study is to propose a standard of converting 3D shape of men in twenties to 2D patterns. This can be a basis for scientific and automatic pattern making for high quality custom clothes. Firstly, representative 3D body shape of men was modeled. Then the 3D model was divided into 3 shells, front, side and back. Among them, the front shell was divided into 4 blocks by bust line and princess line. Secondly, curves are generated on each block according to matrix combination by grid method. Then triangles were developed into 2D pieces by reflecting the 3D curve length. The grid was arranged to maintain outer curve length. Next, the area of developed pieces and block were calculated and difference ratio between the block area and the developed pieces' area is calculated. Also, area difference ratio by the number of triangles is calculated. The difference ratio was represented as graphs and optimal section is selected by the shape of graphs. The optimal matrix was set considering connection with other blocks. Curves of torso upper front shell were regenerated by the optimal matrix and developed into pieces. We validated it's suitability by comparing difference ratio between the block area and the developed pieces' area of optimal section. The results showed that there was no significant difference between block area and the pieces' area developed by optimal matrix. The optimal matrix for 2D developing could be characterized as two types according to block's shape characteristics, one is affected by triangle number, the other is affected by number of raws more than columns. Through this study, both the 2D pattern developing from 3D body shape and 3D modeling from 2D pattern is possible, so it's standardization also possible.

Explosion Characteristics by Different Sizes in the Wall Surface Shape of a Water Gel Barrier (Water Gel Barrier 표면형상의 크기에 따른 폭발특성)

  • Park, Dal-Jae;Kim, Nam-Il
    • Journal of the Korean Institute of Gas
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    • 제16권3호
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    • pp.65-70
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    • 2012
  • Experimental investigations were carried out to examine the explosion characteristics by different sizes in the wall surface shape of a water gel barrier in an explosion chamber, 1,600 mm in length with a square cross-section of $100{\times}100\;mm^2$. The sizes in the wall surface shape were varied by using water gel barriers with a cross-section of $100{\times}200\;mm^2$ and its were varied in the bottom of the chamber away 300, 700 and 1,100 mm, respectively from the closed end of the chamber. The flame propagation images were photographed with a high speed camera and the pressure was recorded using a pressure transducer and a data acquisition system. It was found that as the size of the wall surface shape increased, the flame propagation process and the time taken to reach the maximum pressure were found to be faster. As a result, both the flame speed and the explosion overpressure increased as the size of the wall surface shape increased.

Study on Prediction of Compressive Strength of Concrete based on Aggregate Shape Features and Artificial Neural Network (골재의 형상 특성과 인공신경망에 기반한 콘크리트 압축강도 예측 연구)

  • Jeon, Jun-Seo;Kim, Hong-Seop;Kim, Chang-Hyuk
    • Journal of the Korea institute for structural maintenance and inspection
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    • 제25권5호
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    • pp.135-140
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    • 2021
  • In this study, the concrete aggregate shape features were extracted from the cross-section of a normal concrete strength cylinder, and the compressive strength of the cylinder was predicted using artificial neural networks and image processing technology. The distance-angle features of aggregates, along with general aggregate shape features such as area, perimeter, major/minor axis lengths, etc., were numerically expressed and utilized for the compressive strength prediction. The results showed that compressive strength can be predicted using only the aggregate shape features of the cross-section without using major variables. The artificial neural network algorithm was able to predict concrete compressive strength within a range of 4.43% relative error between the predicted strength and test results. This experimental study indicates that various material properties such as rheology, and tensile strength of concrete can be predicted by utilizing aggregate shape features.

Optimum Shape Design of Bumper Beam Section using Intermediate Response Surface Models (중간매개반응표면모델을 이용한 범퍼 빔 형상의 최적 설계)

  • Park, Dong-Kyou
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제12권3호
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    • pp.1122-1127
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    • 2011
  • A bumper beam plays the important role of absorbing the bulk of bumper impact energy, so it is extremely important to determine the bumper beam section during the initial stage of car development process. This paper uses the Intermediate Response Surface Models (IRSM) technique for the bumper beam section optimization. By using this method, the nonlinear impact force-deflection curve is changed to an approximated curve. This can avoid the excessive 3D nonlinear FEM analysis during the optimization process. Then, the accuracy of the IRSM models is examined by comparing their results with those of the 3D nonlinear FEM. Finally it is shown that the proposed approach is effective to design the 2.5mph vehicle bumper section.

Newly recorded species of the genus Synura (Synurophyceae) from Korea

  • Jo, Bok Yeon;Kim, Han Soon
    • Journal of Ecology and Environment
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    • 제41권1호
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    • pp.9-18
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    • 2017
  • Background: Species in the heterokont genus Synura are colonial and have silica scales whose ultrastructural characteristics are used for classification. We examined the ultrastructure of silica scales and molecular data (nuclear SSU rDNA and LSU rDNA, and plastid rbcL sequences) to better understand the taxonomy and phylogeny within the section Petersenianae of genus Synura. In addition, we report the first finding of newly recorded Synura species from Korea. Results: We identified all species by examination of scale ultrastructure using scanning and transmission electron microscopy (SEM and TEM). Three newly recorded species from Korea, Synura americana, Synura conopea, and Synura truttae were described based on morphological characters, such as cell size, scale shape, scale size, keel shape, number of struts, distance between struts, degree of interconnections between struts, size of base plate pores, keel pores, base plate hole, and posterior rim. The scales of the newly recorded species, which belong to the section Petersenianae, have a well-developed keel and a characteristic number of struts on the base plate. We performed molecular phylogenetic analyses based on sequence data from three genes in 32 strains (including three outgroup species). The results provided strong statistical support that the section Petersenianae was monophyletic, and that all taxa within this section had well-developed keels and a defined number of struts on the base plate. Conclusions: The phylogenetic tree based on sequence data of three genes was congruent with the data on scale ultrastructure. The resulting phylogenetic tree strongly supported the existence of the section Petersenianae. In addition, we propose newly recorded Synura species from Korea based on phylogenetic analyses and morphological characters: S. americana, S. conopea, and S. truttae.