• 수산해양기술연구
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• 제33권4호
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• pp.346-351
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• 1997

The pin bearing strength is one of the most important design parameters for mechanical joints composed of fiber reinforced composites. Thus the effect of the edge distance and the width of specimen on the pin-bearing strength of unidirectional CFRP composites were experimentally investigated in this paper. As results, the failure modes and the pin bearing strength of mechanical joints turned out to depend on the edge distance and also the width of specimen. The failure of specimen with low ratio of width to hole diameter was caused by the net tension from the hole boundary, on the other hand, the failure of specimen with low ratio of edge distance to hole diameter was caused by the shear-out. The bearing strength in case of the failure by shear-out was quite lower than that in case of failure by net tension.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2349-2351
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• 1999

In this paper, the variable absorption rates and DC dielectric breakdown strength of epoxy composites were measured at boiling absorption condition in order to observe the influences of moisture in out door use. Also, in order to improve withstand voltage properties at moisture absorbtion condition. IPN (interpenetrating polymer network) method which had been already reported, was introduced and the influence was investigated. As a result, it was confirmed that the moisture absorption rate was increased and DC dielectric breakdown strength was degraded with boiling time and filler content increasing. On the other hand, it was confirmed that moisture absorption rate and DC dielectric breakdown strength degrading rate were lowered by the improvement of adhesion strength In IPN specimens.

• Journal of Magnetics
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• 제16권4호
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• pp.427-430
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• 2011

The rolled steels for welded structure applied tensile stress have been examined by means of magnetic Barkhausen noise (MBN) method and of a physical parameter obtained from a hysteresis loop. The behaviors of MBN parameters and coercive force with tensile stress were discussed in relation to microstructure changes. There is no change in MBN parameters and coercive force below yield strength. The coercive force rises rapidly with tensile stress above yield strength. On the other hand, the rms voltage and the peak in averaged rms voltage take a maximum around yield strength and then decreases. The magnetomotive force at peak in the averaged rms voltage shows a minimum around yield strength. These phenomena are attributed to the combined effects of cell texture and dislocation density. In addition, the behaviors of MBN parameters around yield strength may be reflected by the localized changes in strain field due to the formation of dislocation tangles.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.63-69
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• 2005

This study was performed to introduce recently developed polyvinylamine as a wet-end process and paper strength improving aids. As a retention and drainage aids, high cationic charged polyvinylamine was more effective at the BCTMP and ONP stock condition than LBKP stock condition. As a dry tensile strength aid, dual system of polyvinylamine with anionic polyacrylamide was the best at the LBKP or ONP stock conditions. On the other hand, polyvinyl amine alone was better than dual system of polyvinylamine with anionic polyacrylamide at the BCTMP condition. As a wet tensile strength aid, polyvinylamine single system and dual system of polyvinylamine with anionic polyacrylamide were good at LBKP, BCTMP and ONP stock conditions. However, poly(aminoamide)-epichlorohydrin resin was good at LBKP and ONP stock conditions but efficiency of poly(aminoamide)-epichlorohydrin resin was remarkably decreased at BCTMP stock condition.

• 대한가정학회지
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• 제9권2호
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• pp.40-47
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• 1971

The purpose of this study was to examine the effects of several methods of the patching on the strength of the seam-texture. The main findings warranted from the present study were as follows : 1. The breaking strength was increased in proportion to the number of stitches in the case of 5 stitches per cm and 7 stitches per cm, not in the case of 9 stitches per cm where the tendency to damage the texture stitches appeared because of the excessive. 2. In comparing the effects of three methods (1. attaching a single patch, 2. attaching a single patch and seaming, 3. attaching several ply patch), no significant difference was found among these three. 3. There was a significant difference between the effects of two methods (1. attaching a single patch and stitching one edge of it on one side of the seam, 2. attaching a single patch and stitching both edges of it on the both sides of seam). In other words, the latter was found to be significantly more effective than the former. 4. In the case of unbalanced texture 9for example, single to two ply, single ply to two ply, or single to three ply), attaching a single patch to single ply and stitching both edges of it, and attaching a single patch to cover the plain-seam and stitching both edges of it, were more effective than attaching a single patch without stitching. 5. In comparing the effects of stitching both edges of the patch in 4 stitches per cm by the machine and by the hand, no significant difference was found. But these were more effective than stitching its both edges in 2 stitches per cm by hand. 6. The plain-seam stitched one edge of patch in 2 stitches per cm by machine and other by hand was significantly stronger than the plain-seam without a patch or with patch not stitched.

• 한국체육학회지인문사회과학편
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• 제57권5호
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• pp.269-279
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• 2018

본 연구의 목적은 한국 암환자들의 근력운동 빈도, 근력, 그리고 건강관련 삶의 질과의 관계를 조사하는 것이다. 이를 위해 2014~2016년 국민건강영양조사 자료를 통합하여, 총 647명의 암환자들의 주당 근력운동 빈도, 악력, 건강관련 삶의 질의 관계를 복합표본 일반선형모형과 로지스틱 회귀분석 방법을 이용하여 분석하였다. 분석결과, 근력운동빈도가 주당 0~1일인 암환자들은 5일 이상인 암환자들에 비해(0.852±0.016 vs. 0.890±0.020 ; p=0.006), 상대 악력이 낮은 암환자들은 높은 그룹에 비해 (0.850±0.018 vs. 0.911±0.016; p<0.001) 건강관련 삶의 질 지수 (EQ-5D index) 가 유의하게 낮게 나타났다. 또한, 주당 근력운동 빈도가 0~1일인 암환자들은 5일 이상인 암환자들에 비해 운동능력에 문제가 생길 확률이 4.07배 (95% CI=1.31-12.63), 상대 악력이 낮은 그룹은 높은 그룹에 비해 운동능력에 문제가 생길 확률이 4.94배 (95% CI=2.14-11.41), 일상생활에서는 5.18배 (95% CI=1.56-17.14), 통증/불편에서는 2.46배 (95% CI=1.33-4.55) 증가했다. 본 연구결과를 통해 암환자들의 근력운동 빈도와 근력이 건강관련 삶의 질과 유의한 관계에 있는 것으로 나타났으며, 꾸준한 근력운동으로 인한 근력향상은 암환자들의 삶의 질 관리에 큰 도움이 될 것으로 사료된다.

• Physical Therapy Rehabilitation Science
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• 제2권1호
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• pp.1-6
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• 2013

Objective: The aim of this review is to explore the latest intervention trends and effects of EMG-triggered functional electrical stimulation on the upper extremity functions in stroke patients. Design: Systematic review on clinical trials. Methods: A systematic literature search was performed to identify clinical trials evaluating the effects of EMG-triggered functional electrical stimulation (EMG-FES) and task-oriented EMG-triggered FES on the hand functions in stroke patients. Literature review was conducted with the following key words: hand function, functional electrical stimulation, task-oriented, stroke. Results: Ten clinical trials were included; 8 of them were randomized controlled trial, 1 was block-randomized, and 1 was a pre-post comparison study. A positive effect of electrical stimulation was reported in the patient groups that were treated with functional electrical stimulation combined with specific tasks, and volitional muscle contraction-triggered stimulation that was synchronized with tasks. Motor capabilities of the hand and arm were improved after the rehabilitation. Conclusions: EMG-triggered electrical stimulation may be more effective than non-triggered electrical stimulation in facilitating the hand functions in stroke patients in terms of muscle strength and voluntary muscle contraction of the paretic hand and arm. Triggered electrical stimulation can be even more effective when it is combined with specific tasks.

• 대한물리의학회지
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• 제15권1호
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• pp.95-104
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• 2020

PURPOSE: A prospective study was conducted to investigate the correlation between the inspiration ability, bone mineral density, lumbar muscle strength, and muscular endurance for the national softball athletes in the national training center. METHODS: The general characteristics of study subjects, inspiration ability, bone mineral density, muscle strength, and muscular endurance data were analyzed using descriptive statistics. In addition, the Pearson product moment correlation was performed to investigate the correlation between the inspiratory capacity, bone mineral density, muscle strength, and muscular endurance. RESULTS: The inspiration, flow rates, and volume were not correlated with the bone mass and bone mineral density. Inspiration and the flow rates and volume were not correlated with the bone mass and bone mineral density. On the other hand, inspiration was correlated with the Extensor muscles (r=.464, p=.006) at an angular velocity of 60°/s and the flexors (r=.463, p=.006) and extensor muscles (r=.615, p<.001) at an angular velocity of 180°/s. The flow rate was also correlated with the extensor muscles (r=.444, p=.009) at an angular velocity of 60°/s and with flexor muscles (r=.432, p=.011) and extensor muscles (r=.589, p<.001) at an angular velocity of 180°/s. Finally, the volume was correlated at the extensor muscles at an angular velocity of 180°/s (r=.534, p=.001). CONCLUSION: The correlation between the inspiratory capacity, bone mineral density, muscle strength, and muscular endurance of softball athletes did not correlate with the bone mass and bone density. On the other hand, the lumbar muscle strength increased with increasing inspiratory capacity.

• 자원환경지질
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• 제37권2호
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• pp.235-244
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• 2004

북동태평양 심해저퇴적물 전단강도 측정의 정확성을 위하여 측정 방법에 따른 전단강도 측정 결과들을 비교하였다. 비교 항목들은 1) 동일한 시료를 두 종류의 베인 전단강도 측정기(수동 베인, 전동 베인)를 이용하여 측정한 결과, 2) 시료채취 후 즉시 선상에서 측정한 결과와 3개월 뒤 육상의 실험실에서 측정한 결과, 3) 동일한 정점에서 채취된 두개시료를 측정한 결과, 그리고 4) 동일한 코어 내에서 4회 반복 실험한 결과이다. 측정 결과, 전단강도 값은 퇴적깊이에 따라 뚜렷한 변화 양상을 보였다. 또한, 동일한 정점에서 채취한 두개의 코어 퇴적물에 대한 전단강도를 비교한 결과, 두 시료에서 측정된 변화폭이 장비차이에 따른 변화와 보관 조건에 의한 변화보다 높게 나타났다. 이와 같은 결과는 퇴적 깊이에 따른 전단강토의 변화가 지질공학적 물성변화에 의해 야기되었음을 지시한다.

• 한국융합학회논문지
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• 제11권5호
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• pp.81-86
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• 2020

본 연구의 목적은 20대 여대생들을 대상으로 수평면에서 어깨각도의 변화에 따라 악력의 차이를 알아보았다. 여대생 20명을 대상으로 바로 선 상태에서 수평면에서 어깨각도 중립자세, 수평면에서 어깨각도 40도 수평모음자세, 수평면에서 어깨각도 40도 수평벌림자세에서 악력검사를 실시하였다. 실험통계는 자세각도에 따른 악력의 결과를 비교하기 위해 일요인 반복측정분석으로 실시하였다. 실험결과를 보면 어개각도의 중립자세에서 약력이 다른 두 자세보다 더 큰 증가하였다. 변화량 검증에서는 중립자세, 어깨각도 40도 수평모음자세 사이에서 유의한 차이를 보였다(p<.05). 수평면에서 어깨각도 중립상태에서 악력의 힘이 가장 큰 결과를 나타났으며 일상생활에서도 중립자세에서 활동을 할 때 효율적인 근력을 사용할 것으로 사료된다.