• 대한기계학회논문집A
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• 제30권4호
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• pp.457-464
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• 2006

The anterior cruciate ligament (ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric positions of the substitute during flexion/extension. The distance between selected attachments on the femur and tibia was computed from a set of measurements using a 6 degree-of-freedom magnetic sensor system. A three-dimensional knee model was constructed from CT images and was used to simulate length change during knee flexion/extension. This model was scaled for each subject. Twenty seven points on the tibia model and forty two points on the femur model were selected to calculate length change. This study determined the maximum and minimum distances to the tibial attachment during flexion/extension. The results showed that minimum length changes were $1.9{\sim}5.8mm$ (average $3.6{\pm}1.4mm$). The most isometric region was both the posterosuperior and anterior-diagonal areas from the over-the-top. The proposed method can be utilized and applied to an optimal reconstruction of ACL deficient knees.

• 한국환경과학회지
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• 제13권6호
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• pp.581-589
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• 2004

This paper describes the amount of food consumption and the change of total weight of abalone under a vibration with noise that can be occurred due to piling work. This experiment was conducted in the aquarium in Yosu National University. In normal situation the juvenile stage shell's(total length is 1～1.5cm) amount of food consumption was 0.81g, the middle stage shell(total length is 3～3.5cm) was 13.61g, and the adult stage shell (Total length is 7～7.5cm) was 43.l9g per 5 organisms in 24 hours, while the experimental group was observed low numerical value compared normal groups. The abalones' food consumption and total weight in both groups, the intermittent and continuance impact with noise and vibration, was reduced during this experiment. The abalones' food consumption and total weight in the experimental groups without vibration were recorded slightly high numerical value than the experimental groups with noise and vibration. Based on this experimental data we could conjecture the noise and vibration are harmful factors to bring up a physiological stress to abalones. Especially, the vibration impact by piling works could produce a considerably unfavorable effect to the abalones than noise impact.

• 유공압시스템학회논문집
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• 제1권2호
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• pp.20-25
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• 2004

In this study, a position control characteristics of pneumatic cylinder with transmission line is analyzed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing stiles of the fluid the diameter and the length of the line. But, the effect of the change of dynamic characteristics of transmission line by the flowing states on the position control characteristics can be neglected because of the friction force of the pneumatic cylinder. So, We assume that the position control characteristics is affected by the diameter and length of the transmission line. The experimental results according to the change of parameter of the transmission line show that the relation between the parameter of the transmission line and the position control characteristics of pneumatic cylinder driving system with the transmission line.

• Ocean Systems Engineering
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• 제12권4호
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• pp.385-402
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• 2022

This paper deals with the study of hydrodynamic pressure in reservoir adjacent to the concrete gravity dam subjected to dynamic excitation. Widely famous finite element method is used to discretize the reservoir domain for modelling purpose. Pressure is considered as nodal variable following Eulerian approach. A suitable nonreflecting boundary condition is applied at truncated face of reservoir to make the infinite reservoir to finite one for saving the computational cost. Thorough studies have been done on generation of hydrodynamic pressure in reservoir with variation of different geometrical properties. Velocity profile and hydrodynamic pressure are observed due to harmonic excitation for variation of inclination angle of dam reservoir interface. Effect of bottom slope angle and inclined length of reservoir bottom on hydrodynamic pressure coefficient of reservoir are also observed. There is significant increase in hydrodynamic pressure and distinct changes in velocity profile of reservoir are noticeable for change in inclination angle of dam reservoir interface. Change of bottom slope and inclined length of reservoir bottom are also governing factor for variation of hydrodynamic pressure in reservoir subjected to dynamic excitation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.332-335
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• 2004

Polymethyl Methacrylate(PMMA) mortars using EPS solution-based binders are prepared with various unsaturated polyester resin(UP) contents of binder, and tested for working life. heat exothorm temperature, length change. compressive strength and temperature dependence of compressive strength. As a result, the working life of PMMA mortar is lengthened with raising UP content of binder. Length change of the mortar was condensed from expansion to shrinkage with increasing UP content, and non shrinkage of the mortar is obtained at about UP content of $2.5\%$. The compressive strength of the mortar is increased with an increase in the UP content and reach maximum at UP content of $5\%$. However thermal resistance improvement of the mortar by increasing UP content was not recognized. UP resin was recommended as an effective agent for shrinkage control and strength development of PMMA mortar.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.714-717
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• 2000

To consider sulfate resistance of cement pastes and motars for 3 types of portland cements which have different $C_3A$ contents an silicate ratio($C_3S/C_2S$), they were immersed in 5% sodium sulfate solution for 400 days. SEM analysis and ($Ca(OH)_2$ contents of cement pastes, and compressive strength and length change of cement mortars, were performed to investigate the effects of ($C_3$ and ($Ca(OH)_2$ contents. According to the results of this study, low heat portland cement pastes, and compressive strength and length change of cement mortars, were performed to investigate the effects of C3A and ($Ca(OH)_2$ contents. According to the results of this study, low heat portland cement had a good sulfate resistances because of a small quantity of gypsum and ettringite due to less ($Ca(OH)_2$ contents. However, ordinary portland cement had an adverse result. This was also confirmed by SEM analysis.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.363-368
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• 1997

In this study, permeable polymer concretes using unsaturated polyester (UP) resin with binder contents of 6, 7 and 8%, filler-binder ratios of 0, 0.5, 1.0%, and various sand and aggregate contents are prepared, and tested for compressive and flexural strengths, length change and water permeability. The effects of the mix proportioning factors on the strength properties, length change and coefficient of permeability of the permeable polymer concrete are discussed. From the test results, increase in the compressive strength and decrease in the coefficient of permeability of permeable polymer concrete are clearly observed with increasing filler-binder ratio. The permeable polymer concretes having a compressive strength of 9.4~28.3MPa and a coefficient of permeability of 0.12~1.93 cm/s can be produced in the consideration of the mix proportioning factors.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.562-564
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• 2005

This paper presents the reasonable design parameters of a SRM for hybrid electric vehicle driving. For the design of SRM, the initial model is designed using the equivalent magnetic circuit method. In order to optimize the SRM for HEV. The initial model is redesigned by FEM with the variation of the stock length and turns of winding. This paper shows that a flat-topped current of a phase can be made from a change of the stack length and the number of turns for high efficiency, high average torque and a lower torque ripple. The change of current falling time as a variation of turn-off angle was shown by FEA. The iron loss and copper loss were described. The torque of the redesigned motor is suitable for low and high speed ranges to drive a HEV that was verified by the speed-torque curve.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1141-1143
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• 2005

This paper presents the reasonable design parameters of a SRM for hybrid electric vehicle driving. For the design of SRM, the initial model is designed using the equivalent magnetic circuit method. In order to optimize the SRM for HEV. The initial model is redesigned by FEM with the variation of the stock length and turns of winding. This paper shows that a flat-topped current of a phase can be made from a change of the stack length and the number of turns for high efficiency, high average torque and a lower torque ripple. The change of current falling time as a variation of turn-off angle was shown by FEA. The iron loss and copper loss were described. The torque of the redesigned motor is suitable for low and high speed ranges to drive a HEV that was verified by the speed-torque curve.

• 한국의류학회지
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• 제37권2호
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• pp.138-150
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• 2013

This study investigates changes in body size (as well as fit) before/after wear, according to the breast and brassiere type. To offer producers basic data on how to develop excellent brassieres, we accordingly conducted preliminary research on 183 20's women. The research revealed that breast-related size and fit change by about 10%; however, the upper length and inner length of breasts decreases. The fit of domed ones is the best and the fit of the elongated ones is the worst; subsequently, a closer representation of the ideal breast leads to a better fit to wear.