• Title/Summary/Keyword: large width-to-thickness ratio

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The Study on the Structural Behavior of Concrete-filled Composite Piers (콘크리트충전 강합성 교각의 구조적 거동에 관한 연구)

  • 김유경
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.151-158
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    • 2000
  • In this paper, It is presented that concrete-filled composite piers have large energy-absorption capacity and high strength and stiffness on account of mutual confinement between the steel plate and filled-in concrete. Concrete-filled composite columns were tested to failure under axial compression and cyclic lateral loading. Displacement ductility index obtained by using the load-displacement relation has been increased with the increment of filled-in concrete length, while it has been decreased according to the incrementation of width-thickness ratio, slenderness ratio and the number of loading cycles. Structural behavior and ductility index estimated for the seismic design showed that composite piers could be used as a very efficient earthquake-resistant structural member. The response modification factor could be re-evaluated for concrete-filled composite piers.

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Inheritance of Grain Weight and Size of a High Yielding Japonica cultivar, Sobibyeo (자포니카 다수성 품종 소비벼의 입중과 입형의 유전)

  • Tae Hwan Noh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.3
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    • pp.142-146
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    • 2003
  • To obtain information on the inheritance of grain weight and grain size of japonica cultivar, Sobibyeo which has high yielding potential and large grain in rice, the genetic variation, heritability and phenotypic correlation of 1,000 grain weight, grain length, width and thickness were investigated in two crosses, Iksan 429/Sobibyeo and Iksan 430/Sobibyeo. The gram characteristics of $\textrm{F}_1$ hybrids exceeded mid-parental values, while grain length: width ratio was intermediate between the parents. In $\textrm{F}_2$ populations, the average grain length, width and thickness were intermediate as mid-parental values, but grain weight exceeded the mid-parental values. In $\textrm{F}_2$ populations of Iksan 429/Sobibyeo and Iksan 430/Sobibyeo, mean 1,000 grain weights were 24.86g and 25.04 g on the average, and ranged 18.4g-32.2g and 19.5g-33.4g, respectively. The segregation mode for grain weight was regarded as a nearly normal distribution in two crosses of $\textrm{F}_2$ populations. Estimates of broad sense heritabilities for grain weight in Iksan 429/Sobibyeo and Iksan 430/Sobibyeo were high as 89.00% and 89.06%, and grain length showed the highest heritability among grain characteristics as 97.45% and 97.35%, respectively. Grain weight was highly correlated with grain length, width and thickness, and grain length was highly correlated with grain width and thickness. These grain characteristics were apparently controlled by polygenes. Accordingly, these traits will be readily improved through selection in the early segregating generations.

A study on application of high strength steel SM570 in bridge piers with stiffened box section under cyclic loading

  • Kang, Lan;Suzuki, Motoya;Ge, Hanbin
    • Steel and Composite Structures
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    • v.26 no.5
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    • pp.583-594
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    • 2018
  • Although a lot of experimental and analytical investigations have been carried out for steel bridge piers made of SS400 and SM490, the formulas available for SS400 and SM490 are not suitable for evaluating ultimate load and deformation capacities of steel bridge piers made of high strength steel (HSS) SM570. The effect of various parameters is investigated in this paper, including plate width-to-thickness ratio, column slenderness ratio and axial compression force ratio, on the ultimate load and deformation capacities of steel bridge box piers made of SM570 steel subjected to cyclic loading. The elasto-plastic behavior of the steel bridge piers under cyclic loads is simulated through plastic large deformation finite element analysis, in which a modified two-surface model (M2SM) including cyclic hardening is employed to trace the material nonlinearity. An extensive parametric study is conducted to study the influences of structural parameters on the ultimate load and deformation capacities. Based on these analytical investigations, new formulas for predicting ultimate load and deformation capacities of steel bridge piers made of SM570 are proposed. This study extends the ultimate load and deformation capacities evaluation of steel bridge piers from SS400, SM490 steels to SM570 steel, and provides some useful suggestions.

Studies on the Yield Potential Increment by Grain Weight in Rice I. Yield capacity and major agronomic characteristics of rice varieties with large grain (벼의 입중증대에 의한 수량성향상에 관한 연구 -제 1 보 대립 벼품종의 주요특성과 수량성-)

  • 양세준;황흥구;손재근
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.29 no.2
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    • pp.109-113
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    • 1984
  • This study was conducted to get basic information about yield capacity and major agronomic characteristics of rice varieties with large grain. The results obtained are as follows; Between grain weight and grain components such as length, width and thickness showed highly positive correlation. The relationship between grain length and grain shape (Length/Width) was clear (r=0.5707${\ast}\;{\ast}$). 1, 000 grain weight of 14 rice varieties with large grain was negatively correlated with number of spikelets per panicle, number of panicles per hill, ripening ratio, total dry matter, grain yield and harvest index, but less clear. The relationship between grain weight of 14 rice varieties with large grain and growth duration was less clear (r=0.440). 1, 000 grain weight of 20 rice varieties differing in grain size showed a highly positive correlation with chalkiness of rice kernel (r=0.8477${\ast}\;{\ast}$).

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Physicochemical Properties and Sensory Evaluation for Grading of Satsuma Mandarin Produced in Cheju (품질규격화를 위한 온주밀감의 물리화학적 및 관능적 특성평가)

  • 고정삼;고경수;임자훈
    • Food Science and Preservation
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    • v.7 no.1
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    • pp.44-50
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    • 2000
  • Physicochemical properties and sensory evaluation of Satsuma mandarin produced in Cheju were investigated . Fruit index(width/Length), soluble solids and acid content of Citrus unshiu marc. var. miyagawa(miyagawa) and C. unshiu marc. var.(okitsu) harvested at 1st December were 1.16 and 1.23, 12.12 and 12.01, 0.97 and 1.09, respectively. and the fruit of miyagawa was showed somewhat round in shape, compared to ikitsu. the taste of miyagawa seemed to be better than okitsu. However, compared to miyagawa, peel thickness was thinner, flesh ratio was higher, and firmness was higher as 0.502kg-force in kitsu. Nevertheless there were some differences among panelist groups in sensory evaluation , middle size of citrus fruits were favorable to most panelists, but except very small or very large size of fruits, there were not so much differences in okitsu. The panelists referred to somewhat flat-shaped fruits from that sensory evaluation score was increased to 1.3 in fruit index. nevertheless there were not so much differences in full-colored fruits, the citrus peel color of reddish yellow was more favorable than greenish or pale yellow color. the score was increased more linearly according to citrusfruit produced in optimum ciltivation area, and was prefered to thinner in peel thickness , Correlation between soluble solids, acid content , Brix/acid ratio and flesh ratio with sensory evaluation score were not showed significantly, it was different to with citrus juice. This data obtained in this experiments are supposed to be applied to the quality evaluation of Satsuma mandarin produced in Cheju .

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Collapse of Thin-Walled Hatted Section Tubes (박판 상형 부재의 붕괴 특성연구)

  • Kim, C.W.;Han, B.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.65-72
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    • 1994
  • Collapse characteristics of thin-walled hatted section tubes are investigated. The square section members with flanges are substituted by the equivalent rectangular tube. The stiffening effects of flanges are transformed to the restraining plate with the equivalency of buckling strength. The square tubes of single-hatted and double-hatted sections are investigated. The double-hatted section members show symmetric and antisymmetric crushing modes depending on the stiffness of flanges. The single-hatted section members show only symmetric modes. The bifurcation point of the compact crushing modes are investigated by experiments and shown almost same thickness-width ratio of the rectangular tubes. A large maximum crippling strength can be obtained by double-hatted section members with proper flange dimensions.

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Effects of Initial Slug Design on the Earring of a Rectangular Battery Case During Impact Extrusion (충격압출 공정에서 초기 슬러그 디자인이 사각 배터리 케이스의 이어링에 미치는 영향 분석)

  • Lim, J. H.;Choi, S.;Chung, W. J.;Shin, J. H.;Lee, J.
    • Transactions of Materials Processing
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    • v.24 no.6
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    • pp.425-430
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    • 2015
  • In the current paper, the effects of initial slug design on the earring of an Al rectangular battery case manufactured by impact extrusion were studied. During impact extrusion, non-uniform metal flow between the long and the short sides of the battery case leads to earring, which is subsequently trimmed. Process parameters such as friction, aspect ratio of the battery case, the die shape and the forming temperature tend to induce earring because they cause greater non-uniform metal flow. Large aspect ratio of the battery case and high friction between slug and die can greatly affect the earring of a rectangular battery case. To make a rectangular battery case without earring, it is necessary to control metal flow uniformly during impact extrusion. One of the ways to reduce the earring is to control the metal flow of slug at the initial upsetting stage. To analyze the effects of the initial slug design on earring, FE analysis was conducted using DEFORM 3D. Two types of initial slug designs were evaluated where volume was removed along either the width or thickness directions. The results show that the initial slug design can be effective in adjusting the uniformity of metal flow.

A study on the upper body type and size of men aged 30-44 for men jacket pattern design (남성 재킷 패턴 설계를 위한 30-44세 남성의 상반신 체형 및 유형별 사이즈 연구)

  • Kwon, Dong Kuk
    • The Research Journal of the Costume Culture
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    • v.29 no.6
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    • pp.881-903
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    • 2021
  • This study aimed to analyze adult men's body sizes and shapes and suggest size specifications to provide preliminary data to academia and industries. A total of 814 adult men aged 30-44 were selected from the 7th Size Korea data, and 55 direct upper body measurement and calculation items were analyzed using SPSS 25.0. In individual Individual differences, thickness, circumference, and width were high, and height and length were low. Height above the waist base line and shoulder dimension decreased in early 40s age group, while height below the waist base line declined as age increased. In addition, buttocks shape changes were found in early 40s age group. According to factor analysis, 'upper body and upper-extremity horizontal size', 'torso height and upper extremity length', 'shoulder dimension', 'upper body length' and 'shoulder angle' were derived. Using clustering analysis, four different body types were classified: i) big abdomen with flat chest, ii) slender with big, raised shoulders, iii) dwarfish with small, droopy shoulders, and iv) obese with large shoulders. 'Slender with big, raised shoulders' was a typical body shape among men aged 30-44. In older participants, the 'big abdomen with flat chest' ratio was low, while 'obese with large shoulders' was more common. This study proposed size specifications by body type considering the above characteristics.

Experimental Study on Compressive Strength of Centrally Loaded Concrete Filled Square Tubular Steel Columns (중심축압(中心軸壓)을 받는 콘크리트충전(充塡) 각형강관(角形鋼管)기둥의 내력(耐力)에 관한 실험적(實驗的) 연구(硏究))

  • Kim, Jong Sung;Oh, Yun Tae;Kwon, Young Hwan
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4 s.29
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    • pp.59-76
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    • 1996
  • Concrete filled steel tube column has a large load carrying capacity through its steel and concrete interaction which makes it useful in construction. However, it has not been used often in a practical construction field. This is partly due to the non-destructive inspection method for concrete filling which has yet to be established. Furthermore, there are the lack of test data and a practical method in evaluating the ultimate load carrying capacity of concrete filled steel tube column. This paper will attempt to predict the ultimate strength of short concrete filled square tubular steel columns through conducting several tests. To accumulate the new test data on concrete filled steel tube columns, a total of 42 specimens of steel tubular columns were monotonically tested under concentric axial force, having the slenderness ratio(${\lambda}=10,\;15,\;20$), width-thickness ratio(d/t=25.0, 33.3) and concrete strengths($F_{c}=210,\;240,\;270kg/cm^{2}$). The hollow sections and concrete filled steel columns were compared to check the lateral confinded effects by steel tube. Through these test results, we propose a coefficient k=3.64 for the strength evaluation formula(10) of concrte filled tubular steel short columns.

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Some Morphological Characteristics of Grain and Chaff of Rice Grains Having Different Specific Gravity (벼임실도에 따른 미립과 조곡의 형질에 관한 연구)

  • 최수일;김연진;나종성;김진기
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.1
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    • pp.28-34
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    • 1982
  • This experiment was conducted to study on some morphological characteristics of rice grain and chaff with specific gravity. The size of grain was greater in grains with heavier specific gravity. Indica varieties were large in length, but short in width and thickness of grain, and was thin in grain form and small in volume of grain compared with Japonica variety. The coefficient of variability was high in grains with lower specific gravity. The accumulation of assimilation product was more influenced with width and thickness rather than length of grain. The percentage of fully ripened grain was high in small size variety. The green rice and imperfect grain showed higher distribution ratio in the lower specific gravity. The chaff of less filled grain had higher content of nitrogen and lower content of potassium and sillicate than the filled.

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