• PNF and Movement
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• 제20권1호
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• pp.59-66
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• 2022

Purpose: The aim of this research was to verify the relationship between three-dimensional (3D) ground reaction force (GRF) and severity of leg length discrepancy (LLD) while walking at a normal speed. It used a 3D motion analysis system with force platforms in standing workers with LLD. Methods: Subjects comprising 45 standing workers with LLD were selected. Two force platforms were used to acquire 3D GRF data based on a motion analysis system during gait. Vicon Nexus and Visual3D v6 Professional software were used to analyze kinetic GRF data. The subjects were asked to walk on a walkway with 40 infrared reflective markers attached to their lower extremities to collect 3D GRF data. Results: The results indicated the maximal force in the posterior and lateral direction of the long limb occurring in the early stance phase during gait had significant positive correlation with LLD severity (r = 0.664~0.738, p <0.01). In addition, the maximal force medial direction of the long limb occurring in the late stance phase showed a highly positive correlation with the LLD measurement (r = 0.527, p <0.01). Conclusion: Our results indicate that greater measured LLD severity results in more plantar pressure occurring in the foot area during heel contact to loading response of the stance phase and the stance push-off period during gait.

• International Journal of Advanced Culture Technology
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• 제4권1호
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• pp.31-36
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• 2016

Morphology evolution of the active layer in bulk hetero-junction organic photovoltaic is modeled and visualized. The width of the phase domain can be predicted using the relationship of characteristics length and evolution time of the process. The 3D numerical simulation of the PCBM/P3HT blend morphology evolution with respect to time is presented. It is observed that the domain width of composition phase can be predicted by using the relationship between value of characteristic length R(t) and evolution time t.

• Structural Engineering and Mechanics
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• 제26권2호
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• pp.211-229
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• 2007

An experimental investigation to determine the transfer length of a seven-wire prestressing strand in different concretes is presented in this paper. A testing technique based on the analysis of bond behaviour by means of measuring the force supported by the prestressing strand on a series of specimens with different embedment lengths has been used. An analytical bond model to calculate the transfer length from an inelastic bond stress distribution along the transfer length has been obtained. A relationship between the plastic bond stress for transfer length and the concrete compressive strength at the time of prestress transfer has been found. An equation to predict the average and both the lower bound and the upper bound values of transfer length is proposed. The experimental results have not only been compared with the theoretical prediction from proposed equations in the literature, but also with experimental results obtained by several researchers.

• 한국패류학회지
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• 제17권1호
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• pp.13-18
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• 2001

1994년 1월부터 1994년 12월까지 전라북도 군산시 하제 연안에 서식하는 개량조개의 성장을 조사하였다. 개량조개의 패각에 나타나는 윤문은 년 1 회 형성되며 주 윤문 형성시기는 8월에서 9월로 조사되었다. 초륜 형성기간은 15 개월 (1.25년)로 나타났다. 각장 (SL) 과 전중 (TW) 간의 관계는 TW = 2.2476 $\times$ $10^{-5}$ SL$^{3.536}$ 이었으며, 각장 (SL) 과 각고 (SH) 간의 관계는 SH = 0.7545 SL - 0.0145 이고, 각장 (SL) 과 각폭 (SW) 간의 관계는 SW = 0.5336 SL - 2.4253 였다. 연령 (t) 에 대한 각장 (SL$_{t}$ ) 과 전중(TW$_{t}$ ) 의 Bertalanffy 성장식은 SL$_{t}$ =60.02[1 - e$^{-0.6458(t-0.3895)}$ ], 이고 Twt = 43.63[1 - e$^{0.6458(t-0.3895)}$ ]$^{3.536}$ 였다.

• 한국수산과학회지
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• 제9권4호
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• pp.251-255
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• 1976

1973년 8월 25일부터 1974년 9월 14일에 걸쳐 제주도 서귀포소재 천지천에서 채집한 총 362미의 은어에 대하여 체장, 체중관계와 비만도를 산란기를 중심으로 검토하여 다음과 같은 결과를 얻었다. 1. 체장, 체중관계에 있어 산란전과 산란기에는 그 관계식이 각각 $W=0.008639\;L^{3.1806}$과 $W=0.01830\;L^{2.7689}$로써 유의성이 인정되었으나 자웅간에는 유의성이 보이지 않았다. 2. 평균체장이 산란기에 감소현상이 나타나는데, 이것은 산란에 참여한 대형어의 폐사에서 온 은어 특유의 현상이라 보았다. 3. 비만도는 산란전인 8월에 평균 $13.45\%_{\circ}$ 였던 것이 9월부터 점차로 감소, 11월 29일에 가서 최저로 평균 $10.25\%_{\circ}$였으며, 다음 해인 2월에는 $11.18\%_{\circ}$로 고복단계에 있었다. 4. 월년어의 대부분은 全전장 $11\~12cm$ 미만의 소형어였다.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.46-53
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• 1995

The anatomy of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens was described and analyzed. Sixteen wood anatomical characters, habit and phenology factors were determined by simple correlation and principal component analysis. Strong positive correlations were found between vessel element length and fiber length, ray width and ray height, simple pits of fiber wall and paratracheal parenchyma distribution. The results of principal component analysis (PCA) disclose the primitive characteristics and the direction of xylem evolution of Korean diffuse-porous woods. The xylem evolution scenario for Korean dicotyledonous woods is considered to be developed in the direction of decreasing trends of vessel frequency, vessel element length, and length/diameter(L/D) ratio of vessel element but increasing trends of vessel diameter, fiber length/vessel element length(F/V) ratio, libriform wood fibers, simple perforation, and homogeneous ray composition. Increase of vessel diameter and decrease of vessel frequency seem to be related to the improvement of conductive efficiency, and increase of the vessel element length and occurrence of scalariform perforation in vessel element may be related to enhanced of conductive safety. Also the libriform wood fibers and ray features appear to have relationship with mechanical support and nutrient metabolism, respectively.

• 산업기술연구
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• 제22권B호
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• pp.21-26
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• 2002

The non-dimensional heat loss from a thermally asymmetric triangular fin is investigated as a function of a ratio of upper and lower surface Biot numbers (Bi2/Bi1), the non-dimensional fin length and tip surface Biot number using the two-dimensional separation of variables method. The effect of fin tip surface Biot number on the variation of the non-dimensional temperature along the sloped upper and lower surfaces for the thermally asymmetric condition is presented. The relationship between the non-dimensional fin length and the fin tip surface Biot number for equal amount of heat loss is also discussed as well as the relationship between upper surface Biot number and tip surface Biot number for equal amount of heat loss.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.27-32
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• 1997

This study was carried out to find the relationship between anatomical characters and compression strength parallel to grain of Pinus densiflora S. et. Z., the representative conifer species in Korea. The results were as follows ; 1. The compression strength parallel to grain increased with the increase of tracheid length and wall thickness. The strength, however, decreased with the increase of height of uniseriate ray and microfibril angle. 2. The major factors affecting compression strength parallel to grain in heartwood were radial diameter of latewood tracheid and wall thickness of earlywood tracheid but length and tangential diameter of latewood tracheid were the important factors in sapwood.

• Structural Engineering and Mechanics
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• 제76권1호
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• pp.67-81
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• 2020

Pretensioned concrete (PC) is widely used in contemporary construction. Bond of prestressing strand is significant for composite-action between the strand and concrete in the transfer and flexural-bond zones of PC members. This study develops a new methodology for quantifying the bond of 18-mm prestressing strand in PC members based on results of a pullout test, the Standard Test for Strand Bond (STSB). The experimental program includes: (a) twenty-four pretensioned concrete beams, using a wide range of concrete compressive strength; and (b) twelve untensioned pullout specimens. By testing beams, the transfer length, flexural-bond length, and development length were all measured. In the STSB, the pullout forces for the strands were measured. Experimental results indicate a significant relationship between the bond of prestressing strand to the code-established design parameters, such as transfer length and development length. However, the code-predictions can be unconservative for the prestressing strands having a low STSB pullout force. Three simplified bond equations are proposed for the design applications of PC members.

• 한국생산제조학회지
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• 제22권3호
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• pp.402-407
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• 2013

In this paper, the image processing for flexible disk grinding and the effect of the grinding conditions on the flat zone length of a workpiece are investigated, with the purpose of automating the grinding process. To accomplish this, three issues should be carefully studied. The first is finding the relationship between the flat zone length and the grinding conditions such as the cutting speed and feeding speed. The second is developing a neural network algorithm to predict the flat zone. The third is developing an image processing algorithm to measure the flat zone length of a workpiece. Slope analysis is used to determine straight and curved sections during the image processing. For verification, the estimated length and the length from the image processing are compared with the length measured by a projector. There is a minimum difference of 1.7% between the predicted and measured values. The results of this paper will be useful in compiling a database for process automation.