• 제목/요약/키워드: Width-to-length ratio

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원형기둥-상자형보 접합부의 응력평가식 개발 (Development of Stress Evaluation Equation of Circular Column-Box Beam Connections)

  • 이주혁;김정환;박용명
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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    • pp.227-234
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    • 2003
  • This study presents the stress evaluation equations of circular column-box beam connection in steel frame piers. FEM analysis were carried out for circular column-box beam connection. Analysis models were made for design parameters such as joint angle, span length-width ratio(L/B), sectional-area ratio(S=A/sub w/A/sub f/), and circular column-box beam stiffness ratio(Ic/Ib). Analysis results were compared to the existing equation. Based on analysis results the stress evaluation equations of circular column-box beam connection are proposed by regression analysis.

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Comparison of the Quality Characteristics of the Rice yield Trial Lines in the Central Plain Region for Four Years

  • Jeong Heui Lee;Jieun Kwak;Hyun-Jin Park;You-Geun Oh;Jeom-Sig Lee;Yu-Chan Choi;Seon-Min Oh
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.325-325
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    • 2022
  • In order to developing high-quality rice varieties and processing varieties, systematic and stable evaluation of physicochemical properties is required for breeding lines. In this study, we compared the quality characteristics evaluation results of rice breeding lines for cooked rice, special rice, and whole crop silage rice adapted to central plain region (Suwon) in order to use as basic data for future rice variety development. Brown rice length/width ratio, head rice ratio, protein content, amylose content, alkali digestion value(ADV) and Toyo value were analyzed to evaluate the quality characteristics of yield trial lines cultivated in Suwon for four years (2017-2020). Brown rice length/width ratio, head rice ratio, protein content, ADV and Toyo values showed significant differences by year, but there was no significant difference in amylose content (p<0.05), which showed little environmental variation. The head rice ratio and Toyo value showed an increasing trend, while the protein content showed a decreasing trend. However, the protein content was the highest in 2020, which is thought to be owing to little sunlight hours due to heavy rainfall in 2020. The protein content of whole crop silage rice was 8.1%, which was significantly higher than that of other lines (p<0.05). Toyo value of medium-maturing and early-maturing lines were 67.6 and 73.7%, respectively, and the Toyo value of medium-maturing lines was higher than that of the early-maturing lines (p<0.05). In correlation analysis among the quality characteristics of the rice lines for cooked rice, significant positive correlations were detected between Toyo value and head rice ratio, amylose content, ADV, and a negative correlation was observed between Toyo value and protein content (p<0.05).

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Comparison of quality property between fresh cooked rice and re-heated cooked rice

  • Sim, EunYeong;Woo, Koan Sik;Kim, Mijung;Park, Hye-Young;Oh, Sea Kwan;Lee, Chunki
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.287-287
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    • 2017
  • The objective of this study was to evaluate difference of quality properties of between fresh cooked rice and re-heated cooked rice after retrogradation. Nine rice varieties raised by NICS were compared the properties of physicochemical, texture, sensory evaluation, toyo glossiness value, pasting properties. Among nine rice cultivars, the changes of weight and length-width ratio of after soaking as well as cooking showed how water absorbed in each rice granule. The amount of water absorption after soaking was highest in Wolback (semi-waxy), Hiami and lowest in Samgwang, Seonpum, Ilpum. After cooking, the amount of water absorption was high in Dasan 1 and Andabyeo, however low in Ilpum. In the length-width ratio after soaking, Wolback (semi-waxy cultivar) and Anda (indica cultivar) increase their volume relatively as their shape are while others increased more in length than width. Among cooked rice, the highest value of length-width ratio shows in Anda, Dasan1, Hiami and Seonpum, the Wolbak was similar to that of non-glutinous rice. After cooking, the others stored at $10^{\circ}C$ for 16 hours for retrogradation (imitated at convenience store). Then re-heated using by microwave. Pasting properties were considerably affected by storage temperature and periods of rice. The setback showed in the following order: Wolback (-92.25 RVU, the lowest retrogradation) < Seonpum (-35.20) < Chindle (-22.08) < Jungsanggold (-21.98). Toyo glossiness value of cooked rice showed in the following order: Chindle (82.40) > Samgwang (79.43) > Hiami (79.23). Sensory evaluation of re-heated rice of Jungsanggold, Samgwang, and Chindle were 78.97, 78.36, and 77.35, respectively. Hardness, elasticity, and toughness of re-heated rice ware increased compared to cooked rice, whereas cohesiveness was decreased. Hardness and elasticity is higher in Seonpum, Dasan1 and Hiami, toughness is higher in Jungsanggold, Samgwang and Wolbak. Cohesiveness of Jungsanggold and wolbak showed higher than others.

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미국삼 종자의 매장처리 : 배 성장과 온도 (Stratification of American Ginseng Seed: Embryo Growth and Temperature)

  • John, T.A.Proctor;Dean, Louttit
    • Journal of Ginseng Research
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    • 제19권2호
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    • pp.171-174
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    • 1995
  • Freshly harvested American ginseng (Panax quinquefolium L.) seeds were stratified at two locations over each of three years. Seed development and temperature in the stratification boxes were investigated until the seed was removed 12 months later and direct-seeded in the field. During stratification and seeding (14 months) three embryo stages were identified. In Stage I of 250 days (Sept. to mid-May) embryo length increased from about 0.5 to 1.0 mm: in Stage II of 100 days (mid-May to late Aug. when seeded) length increased to 2.0 mm and in Stage III (late Aug. to late Nov.) length increased to 5.3 mm. Excerpt split width could also be placed in three stages. Changes in embryo length correlated with embryo endosperm length ratio. Insertion compression tests showed that the excerpt softened rapidly in late Stage II and throughout Stage III. The stratification box temperatures at all depths (10, 25 and 50 cm) never exceeded -2$^{\circ}C$ even when the air temperatures dropped to -13$^{\circ}C$ and were, therefore not damaging to the seeds.

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Groove를 활용한 풍력블레이드 성능향상을 위한 수치적 연구 (Numerical Analysis on Performance Improvement for Wind Blade by the Groove)

  • 홍철현;서성호
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권4호
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    • pp.475-482
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    • 2011
  • 본 연구는 풍력블레이드의 공력특성 향상을 위한 기초연구로서, 익형의 표면에 형성된 groove의 형상에 따른 양항비의 개선정도를 전산해석을 통해 분석하였다. 본 연구의 계산 범위에서 경계층(${\delta}$)과 groove 깊이(h)의 비는 1.1, groove 깊이(h)와 폭(d)의 비는 0.1, groove 사이의 거리(p)와 폭(d)의 비는 1.2, groove 수는 2개의 경우에서 양항비가 8.7% 향상된 결과를 보였다. Groove에 의한 양항비의 개선정도가 특정 받음각 이후에서도 지속됨을 확인하였다.

Interspecific and Intraspecific Variation in Pollen Grains of Quercus Subgenus Lepidobalanus Endl. in Korea

  • Kim, Sang-Yong;Kim, Kae hwan
    • Plant Resources
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    • 제5권1호
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    • pp.17-28
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    • 2002
  • Palynological characters such as pollen grain polar axis length (PL), pollen equatorial diameter (ED), colpus length, colpus width, and P/E ratio of six species of Quercus subgenus Lepidobalanus Endl. from Korea were studied. A significant interspecific variation, unequal distances between the species, and various degree of intraspecific variations were found. The taxonomic value of the pollen morphology parameters measured was found to vary according to species. These results suggest a possible relationship between parameters measured and ploidy level of the Quercus species studied.

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J-적분과 균열선단개구변위에 관한 구속계수 m의 평가 (An Estimation of Constraint Factor on the ${\delta}_t$ Relationship)

  • 장석기
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권6호
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    • pp.24-33
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    • 2000
  • This paper investigates the relationship between J-integral and crack tip opening displacement, ${\delta}_t$ using Gordens results of numerical analysis. Estimation were carried out for several strength levels such as ultimate, flow, yield, ultimate-flow, flow-yield stress to determine the influence of strain hardening and the ratio of crack length to width on the $J-{\delta}_t$ relationship. It was found that for SE(B) specimens, the $J-{\delta}_t$ relationship can be applied to relate J to ${\delta}_t$ as follows $J=m_j{\times}{\sigma}_i{\times}{\delta}_t$ where $m_j=1.27773+0.8307({\alpha}/W)$, ${\sigma}_i:{\sigma}_U$, ${\sigma}_{U-F}={\frac{1}{2}} ({\sigma}_U+{\sigma}_F$), ${\sigma}_F$, ${\sigma}_F}$ $Y=({\sigma}_F+{\sigma}_Y)$, ${\sigma}_Y$

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Bending analysis of a micro sandwich skew plate using extended Kantorovich method based on Eshelby-Mori-Tanaka approach

  • Rajabi, Javad;Mohammadimehr, Mehdi
    • Computers and Concrete
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    • 제23권5호
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    • pp.361-376
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    • 2019
  • In this research, bending analysis of a micro sandwich skew plate with isotropic core and piezoelectric composite face sheets reinforced by carbon nanotube on the elastic foundations are studied. The classical plate theory (CPT) are used to model micro sandwich skew plate and to apply size dependent effects based on modified strain gradient theory. Eshelby-Mori-Tanaka approach is considered for the effective mechanical properties of the nanocomposite face sheets. The governing equations of equilibrium are derived using minimum principle of total potential energy and then solved by extended Kantorovich method (EKM). The effects of width to thickness ratio and length to width of the sandwich plate, core-to-face sheet thickness ratio, the material length scale parameters, volume fraction of CNT, the angle of skew plate, different boundary conditions and types of cores on the deflection of micro sandwich skew plate are investigated. One of the most important results is the reduction of the deflection by increasing the angle of the micro sandwich skew plate and decreasing the deflection by decreasing the thickness of the structural core. The results of this research can be used in modern construction in the form of reinforced slabs or stiffened plates and also used in construction of bridges, the wing of airplane.

스테이터의 형태에 따른 Cross형 초음파 회전모터의 구동특성 (Driving Characteristics of the Cross Type Ultrasonic Rotary Motor Dependent on Shape of the Stator)

  • 장현호;박태곤
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권10호
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    • pp.433-437
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    • 2005
  • This paper studied Rotary type ultrasonic motor which has cross type stator. The stator consists of hollowed cross type metal which has four piezoelectric ceramics on the ends of cross bars. When two harmonic voltages which have 90$^{\circ}$ phase difference given to ceramics, the elliptical motion was generated in the inside tips. Inside tips are contact with rotor and these elliptical motions are rotate the rotor The finite element analysis was used to optimize the dimension and displacement of the stator. And the analyzed results were compared with the experimental results of the motor. As results, the speed and the torque of motor was increased by increasing width of the cross bar. And the speed and torque o( motor was not influenced to length of cross bar. The speed and torque was linearly increased by increasing voltage. The maximum torque was generated when the motor fabricated length of cross bar and width of ceramics in the ratio of 1:2.

Analysis on the body size selectivity for multi-species of discarding juvenile fishes in the bottom trawl

  • KIM, Yonghae
    • 수산해양기술연구
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    • 제55권3호
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    • pp.181-189
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    • 2019
  • Discarding juvenile fishes under girth 16 cm nearly equal to inner perimeter of codend mesh size collected by a cover net method in bottom trawl. The body size of the main five species (mackerel, horse mackerel, sea bream, melon seed and black throat seaperch) was measured for their body length, girth, weight, height and width and analyzed size selectivity. Frequency of penetrating fish as retention in a cover net was less than 40% of total number of juvenile discarding fish. The most of body length or girth of five species were significantly different between in the codend and in the cover net. The 50% selection girth in the cover net ranged 8-11 cm were smaller than those in the codend ranged 9-13 cm by the species respectively. The 50% selection body length was significantly related with the ratio of body height (H) by body width (W) both for in the codend or in the cover net while 50% selection girth was not significantly related with H/W. Furthermore 50% selection fish size by fish species between in the codend and in the cover net was not significantly different both in body length or girth. Therefore, the girth selectivity represented possibly as one unique value regarding fish body shape was considered as more useful method for multi-species catch in trawl.