• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.285-299
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• 2004

The purpose of this study is to identify female 500m sprint start motion by the center of gravity position in short track speed skating. The center of gravity position ratio was divided into three type(type A front : 80%-back : 20%, type B front : 70%-back 30%, type C front: 50%-back : 50%). Three video cameras were used for 3D motion analysis with DLT method and the results were as follows: The elapsed time in starting motion was appeared that type B was the shortest and type A was the longest. It was appear that the stroke length of type A was longer than that type B and C during starting phase. This result was similar to displacement of center of gravity. It was appeared that skill type of center of gravity position ratio type B' ankle and knee joint angle were lower than that of type A and C. Observing these results it was conclusion that skill type B of center of gravity position ratio was more faster than that of type A and C. But it is important that these skill type needed to verifying more subjects.

• The Korean Journal of Malacology
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• v.11 no.2
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• pp.135-145
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• 1995

A morphological andk histochimical study on the amterior tintacular antenna of Korean sulg, Incilaria fruhstorferi was conducted under the light microscopic observations. The histological sturctures of the antenna were apparently divided into three parts such as the epithelium, the connective tissues and the muscular layers. The cells forming the antenna were classified into several types on the basis of their morphological and histochemical characteristics. The simple columnar epithelium cotering the whole antenna was composed of supporting cells, sensory neurons and type-a clear cells. The connective tissue was consisted of dispersed large cells, type-b clear cells and 7 types of secretory cills such as type-A, type-B, type-F, thpe-G, type-H, type-J and type-K. The large cells found in the form of group situated only in the stalk of the antenna. The large cells possessed relatively small nuclei as compared with their cytoplasm. The cytoplasm positively reacted upon alcian blue, and the nucleus was PASpositive. The type-a and type-b clear cells which were irregular in shape showed no evident reaction against various stains employed in the present study. The secrtory cells were observed mainly in the connective tissues and in the muscular layers. Histochemical components of the type-A, type-B and K were identified as acid mucopolysaccharides and those of type-F and H were neutral mucopolysaccharides. The muscular layders supporting the epithelium possessed the type-B and F secretory cells which were also observed in the connective tissues.

• Journal of Energy Engineering
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• v.22 no.4
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• pp.333-337
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• 2013

본 논문에서는 태양전지의 Ribbon 두께(A-type:0.2mm, B-type:0.25mm)에 따라 3가지 온도조건 ($-40{\sim}65^{\circ}C$, $-40{\sim}85^{\circ}C$, $-40{\sim}105^{\circ}C$)으로 열충격 시험을 수행하였다. 그 결과, A, B type 별 초기 평균효율은 15.2%로 같았다. 하지만, 열충격 시험(600 Cycle) 후 Condition 1에서 A-type 7.5%, B-type 7.7%, Condition 2에서는 8.6%, 13.2%를 나타내었다. Condition 3에서는 각각 11.6%, 19.9%의 감소율을 나타내었다. 열충격 시험 후 A-type보다 Ribbon두께가 두꺼운 B-type의 효율이 크게 감소하였다. 이는 A, B type 모두 이종재료 접합부의 금속간화합물(IMC)층이 형성되어 전기적 저항이 증대된 것으로 판단된다. 또한, B-type의 I-V 특성 곡선 및 EL을 분석한 결과, p-n층이 파괴되고, 병렬저항이 감소하여, 장기적 신뢰성에서 A-type 보다 더 취약한 것으로 나타났다. 향후 태양전지 Ribbon 형상에 따른 장기 신뢰성 특성에 대해 수치해석 및 시뮬레이션 분석이 수반되어야 할 것이다.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.1-8
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• 2008

The lateral strength test of bending type was done to investigate the lateral capacity of the double bolt connection of domestic larix glulam according to bolt spacing. In the shear specimen, which is bolted connection in the inserted plate type, the hole of bolt was made, changing the diameter of bolt (12 mm and 16 mm), the number of bolt (single bolt : control and double bolt), the direction of bolt row (in parallel to grain : Type-A and in perpendicular to grain : Type-B) and the bolt spacing (Type-A : 4 d and 7 d and Type-B : 3 d and 5 d). Lateral capacity and failure mode of bolt connection were compared according to conditions. In prototype design (KBCS, 2000), the reduction factor of the allowable shear resistance that the bolt spacing is reduced was calculated. The results were as follows. 1) Bearing stress per bolt in the single and double bolt connection of Type-A was directly proportional to bolt diameter and bolt spacing. Bearing stress of Type-B decreased as bolt diameter was increased, and decreased by 2~10% when bolt diameter was increased. 2) In the single bolt connection and the double bolt connection of Type-A, the splitted failure was formed in the edge direction. When the bolt spacing was 3 d in Type-B, bolt was yielded more in the part of tension than in the part of compression, and the splitted failure started at the bolt in the part of tension. In the 5 d spacing specimen, the bolt in the part of tension was yielded similarly to bolt in the part of compression, and the splitted failure started in the part of compression. 3) In the prototype design, the reduction factor was calculated by non-dimensionizing the yielding load in the standard of bolt spacing (Type A : 7 d and Type B : 5 d). In 12 mm bolt connection, the reduction factor of bolt spacing 4 d (type-A) and single bolt connection was 0.87 and 0.55, respectively, and the reduction factor of bolt spacing 3 d (Type-B) and single bolt connection was 0.91 and 0.55, respectively. In 16 mm bolt connection, the reduction factor of bolt spacing 4 d (type-A) and single bolt connection was 0.96 and 0.76, respectively, and the reduction factor of bolt spacing 3 d (Type-B) and single bolt connection was 0.91 and 0.77, respectively.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.45-53
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• 2006

The purpose of this study was to analyze exercise related mechanical variables according to performance levels and Kumi-kata types in elite judo players (G1) and non-elite judo players, namely university players (G2). To achieve this purpose, three players in G1 whose main special skill was Morote-Seoinage and three university judo players(G2) was selected as comparative group. Then they were examined for distinguishing A and B types of Kumi-kata. Analyzed variables were the time required to show skills, knee degree, elbow degree. After analysing this study, conclusions were derived as follows. 1. In total necessary time of showing skills according to group of Kumi-kata type, G2 was longer than G1 in both A type (20.9%) and B type (23.7%). In necessary time of phase, in only 3P, G1 was shorter than G2 in A type (50%) and B type (75%). There was no difference in time required of 1P and 2P according to Kumi-kata type of group and in only 3P, B type was shorter than A type in both B type (75%) of G1 and B type (50%) of G2 2 There was no difference in elbow degree of offensive arm according to group of Kumi-kata type, however in A and B types, G1 could use skills by extending in kake phase, but G2 could use skills by bending. Elbow degree of offensive arm according to Kumi-kata type of group showed difference in E1. and F2 of G1. A and B types of G1 extended elbow degree in Kake phase, but G2 bent elbow degree so exercise program which could movable range extensively in Kake phase is needed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.95-103
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• 1992

Laminar natural convection heat transfer from an isothermal rectangular beam attached to horizontal and vertical adiabatic plates has been studied for various aspect ratios of the beam and Grashof numbers. The local Nusselt number was increased with decreasing H/B for the constant beam width, B, and with increasing H/B for the constant beam height, H. The total mean Nusselt number of the vertical type was higher than that of horizontal type in the range of H/B.leq.0.52, but reversed in the H/B>0.52 at constant beam width. The total mean Nusselt number of the horizontal type was generally higher than that of vertical type at constant beam height. The total mean Nusselt number of the vertical type was higher than that of horizontal type in the range of H/B.leq.0.43 at constant wetted perimeter, but reversed in the H/B$\leq$0.43.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.5-15
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• 2007

Objective: The purpose of this study was to evaluate the mechanical performance of mini-screws during insertion into artificial bone with use of the driving torque tester (Biomaterials Korea, Seoul, Korea), as well as testing of Pull-out Strength (POS). Methods: Experimental bone blocks with different cortical bone thickness were used as specimens. Three modules of commercially available drill-free type mini-screws (Type A; pure cylindrical type, Biomaterials Korea, Seoul, Korea, Type B; partially cylindrical type, Jeil Medical, Seoul, Korea, Type C; combination type of cylindrical and tapered portions, Ortholution, Seoul, Korea), were used. Results: Difference in the cortical bone thickness had little effect on the maximum insertion torque (MIT) in Type A mini-screws. But in Type B and C, MIT increased as the cortical bone thickness Increased. MIT of Type C was highest in all situations, then Type B and Type A in order. Type C showed lower POS than Type A or B in all situations. There were statistically significant correlations between cortical bone thickness and MIT, and POS for each type of the mini-screws. Conclusion: Since different screw designs showed different insertion torques with increases in cortical bone thickness, the best suitable screw design should be selected according to the different cortical thicknesses at the implant sites.

• Animal cells and systems
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• v.3 no.1
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• pp.89-96
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• 1999

Nucleotide sequences of a 501 base-pair (bp) fragment in the mitochondrial cytochrome b (cyt b) gene were analyzed for 12 populations of Rana rugosa from Korea and Japan using a polymerase chain reaction (PCR) and direct silver sequencing. Two genetically distinct groups (type-A and type-B) were found in Korea. Type-A was found throughout most of South Korea and type-B was restricted to the mid-southeastern regions (Samchok, Yongdok, Chongsong and Pohang). But in the Tonghae population, both types were found. The level of mitochondrial DNA (mtDNA) sequence differences ranged from 0% to .0.8% among six populations of type-A, and 0 to 1.0% among 4 populations of type-B. However, sequence differences between type-A and type-B ranged from 5.4% to 6.6%, Using Kimura's two-parameter distance, the level of genetic sequence divergence between type-A and type-B was 6.7%. The Japanese R. rugosa was clustered very far from the Korean R. rugosa with 14.7%. In the neighbor-joining and UPGMA tree, all Korean samples were grouped, but subdivided into two types in 99% of the bootstrap iteration.

• East Asian mathematical journal
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• v.31 no.5
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• pp.695-706
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• 2015

Let ${\mathcal{H}}$ be an infinite dimensional complex Hilbert space, and let $B({\mathcal{H}})$ be the algebra of all bounded linear operators on ${\mathcal{H}}$. Recall that an operator $T{\in}B({\mathcal{H})$ has property B(n) if ${\mid}T^n{\mid}{\geq}{\mid}T{\mid}^n$, $n{\geq}2$, which generalizes the class A-operator. We characterize the property B(n) of weighted shifts $S_{\lambda}$ over (${\eta},\;{\kappa}$)-type directed trees which appeared in the study of subnormality of weighted shifts over directed trees recently. In addition, we discuss the property B(n) of weighted shifts $S_{\lambda}$ over (2, 1)-type directed trees with nonzero weights are being distinct with respect to $n{\geq}2$. And we give some properties of weighted shifts $S_{\lambda}$ over (2, 1)-type directed trees with property B(2).

• Journal of Forest and Environmental Science
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• v.33 no.1
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• pp.66-73
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• 2017

This study was conducted to evaluate the ecological attributes of forest types which were classified by cluster analysis in the natural forest of Mt. Odae on the basis of the vegetation data (232 sampling points) from the point-quarter sampling methods. For the classified types, the species composition was expressed by importance value to describe the stand structure and the species diversity was quantified using the Shannon's diversity index. Recognized forest types were 1) Quercus mongolica-Pinus densiflora-Betula ermanii forest type, 2) Mixed mesophytic forest type, 3) Q. mongolica forest type, 4) B. ermanii forest type. Species diversity indices of total and overstory were highest in the Mixed mesophytic forest type (3.465 and 2.942), and lowest in the B. ermanii forest type (0.118 and 0.832). In addition to that, Q. mongolica-P. densiflora-B. ermanii forest type was calculated as 3.226 and 2.565, and Q. mongolica forest type was calculated as 2.776 and 1.218 in total and overstory, respectively. It was considered that after the P. densiflora and B. ermanii first invaded and site condition became good, Q. mongolica-P. densiflora-B. ermanii forest type was dominated by Q. mongolica. Mixed mesophytic forest type showed the most stable stand structure with various species distributed uniformly. Q. mongolica forest type would preserve the present stand status for a while, and the B. ermanii in B. ermanii forest type would be pressed by other species over time.