• 전기학회논문지
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• 제66권11호
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• pp.1628-1633
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• 2017

The purpose of this study was to identify the difference and correlation in elbow joint maximal flexion strength according to measurement methods and characteristics of muscular contraction, and to develop the predictive equation of elbow joint maximal flexion strength for the optimal exercise intensity setting and accurate measurement. Subjects were 30 male university students. Elbow joint maximal flexion strength of isokinetic contraction, isometric contraction at $75^{\circ}$ elbow joint flexion position, isotonic concentric 1RM, manual muscle strength (MMT) were measured with isokinetic dynamometer, dumbbell, and manual muscle tester. Pearson's r, linear regression equation, and multiple regression equation between variables were calculated. As a result, the highest value was isometric contraction. The second highest value was MMT. The third highest value was isokinetic contraction. 1RM was the lowest. Predictive equations of elbow joint maximal flexion strength between isometric and isokinetic contraction, between isometric contraction and 1RM, among isometric contraction, 1RM, and body weight were developed. In conclusion, 1RM and isokinetic elbow joint maximal flexion strength could be seemed to underestimate the practical elbow joint maximal flexion strength. And it is suggested that the developed predictive equations in this study should be useful in criteria- and goal-setting for resistant exercise and sports rehabilitation after elbow joint injury.

• 대한치과보철학회지
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• 제29권3호
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• pp.101-110
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• 1991

The purpose of this study was to compare the repaired joint strength among several edge profiles after denture repair. For this study, eight edge profiles were used for repair methods and five self-curing resin brands were used for repair materials. Break away loads were tested after 1 hr., 24 hrs. and 1 week. Instron was used for testing the transverse strength of repaired specimen. The results were as follows. 1. Repaired joint strength was about 35-65% of that of original specimen. 2. Joint strengths of round, inverse knife, inverse rabbit, lap ogee joint were higher tnan that of traditional simple butt joint 3. Joint strength of the simple butt joint was low significant. 4. Joint strengths after 1 hr. specimen were lower than those of 24 hrs. and 1 week specimens in joint strengths. 5. There were no significant differences between 24 hrs. and 1 week specimens in joint strengths. 6. It look more than 24 hours to gain satisfactory physical property after repairing the fractured denture base when self-curing resin was used for repair.

• Advances in concrete construction
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• 제6권5호
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• pp.527-543
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• 2018

Crack control of precast members is crucial for durability. However, there is no clear provision to check the crack width of precast joints. This study presents an experimental investigation of loop joint details for use in a precast bridge deck system. High strength concrete of 130 MPa was chosen for durability and closer joint spacing. Static tests were conducted to investigate the cracking and ultimate behavior of test specimens. The experimental results indicate that current design codes provide reasonable estimation of the flexural strength and cracking load of precast elements with loop joint of high strength concrete. However, the crack width control of the loop joints with high strength concrete by the current design practices was not appropriate. Some recommendations to improve crack control of the loop joint were derived.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.582-588
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• 1998

The experimental study for the interior beam-column joint for high strength conccrete using Belite cement is presented. Test parameters are compressive strength, flexual strength ratio and joint shear stresslevel. The results from cyclic loading tests show different behaviors from the various parameters. Also, The different behaviors on beam-column joint can be achived by the different concrete strength.

• Advances in Computational Design
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• 제1권1호
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• pp.61-77
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• 2016

Seismic performance of structures depends on the force flow mechanism inside the structure. Discontinuity regions, like beam-column joints, are often affected during earthquake event due to the complex and discontinuous load paths. The evaluation of shear strength and identification of failure mode of the joint region are helpful to (i) define the strength hierarchy of the beam-column sub-assemblage, (ii) quantify the influence of different parameters on the behaviour of beam-column joint and, (iii) develop suitable and adequate strengthening scheme for the joints, if required, to obtain the desired strength hierarchy. In view of this, it is very important to estimate the joint shear strength and identify the failure modes of the joint region as it is the most critical part in any beam-column sub-assemblage. One of the most effective models is softened strut and tie model which was developed by incorporating force equilibrium, strain compatibility and constitutive laws of cracked reinforced concrete. In this study, softened strut and tie model, which incorporates force equilibrium equations, compatibility conditions and material constitutive relation of the cracked concrete, are used to simulate the shear strength behaviour and to identify failure mechanisms of the beam-column joints. The observations of the present study will be helpful to arrive at the design strategy of the joints to ensure the desired failure mechanism and strength hierarchy to achieve sustainability of structural systems under seismic loading.

• The Journal of Korean Physical Therapy
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• 제33권2호
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• pp.91-96
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• 2021

Purpose: This study investigated the effects of cryotherapy on the ankle joint muscle strength and balance ability in stroke patients with ankle joint muscles. Methods: In this study, 20 patients with chronic stroke were recruited from a rehabilitation hospital. The patients were divided into two groups: a cryotherapy group (10 patients) and a control group (10 patients). The cryotherapy group performed sit-to-stand training for 15 minutes and then cryotherapy for the minutes. In the control group, after sit-to-stand training for 15 minutes, blocked cryotherapy was provided for three minutes. In both groups, the interventions were provided five times a week for three weeks. The strength of the ankle joint muscles was measured before and after the training using the Biodex systems 3. The static balance ability was measured using balancia software, and the dynamic balance ability was measured by performing the sit-to-stand test (FTSST) five times. Results: After the training periods, the cryotherapy group showed significant improvement in the ankle dorsiflexor strength, ankle plantarflexor strength, weight distribution of the affected side, and FTSST compared to the control group (p<0.05). Conclusion: Based on these results, cryotherapy could be considered an effective method to improve the strength of ankle joint muscles. Cryotherapy improves muscle strength as it increases the motor neuron excitability. Therefore, cryotherapy may be considered to improve the strength of the ankle joint muscles of stroke patients.

• Earthquakes and Structures
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• 제7권5호
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• pp.705-718
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• 2014

This paper presents an analytical model for determining the transverse reinforcement required for reinforced concrete exterior beam-column joints subjected to reversed cyclic loading. Although the joint aspect ratio can affect joint shear strength, current design codes do not consider its effects in calculating joint shear strength and the necessary amount of transverse reinforcement. This study re-evaluated previous exterior beam-column joint tests collected from 11 references and showed that the joint shear strength decreases as the joint aspect ratio increases. An analytical model was developed, to quantify the transverse reinforcement required to secure safe load flows in exterior beam-column joints. Comparisons with a database of exterior beam-column joint tests from published literature validated the model. The required sectional ratios of horizontal transverse reinforcement calculated by the proposed model were compared with those specified in ACI 352R-02. More transverse reinforcement is required as the joint aspect ratio increases, or as the ratio of vertical reinforcement decreases; however, ACI 352R-02 specifies a constant transverse reinforcement, regardless of the joint aspect ratio. This reevaluation of test data and the results of the analytical model demonstrate a need for new criteria that take the effects of joint aspect ratio into account in exterior joint design.

• 한국산학기술학회논문지
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• 제16권3호
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• pp.2073-2078
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• 2015

본 연구에서는 선 자세에서 팔굽관절 각도에 따른 악력과 위팔노근의 두께 변화를 확인하여 팔굽관절 각도가 악력에 미치는 영향을 알아보고자 하였다. 연구를 위해 건강한 대학생 30명을 선별한 후, 선 자세에서 팔굽관절 $0^{\circ}$, $90^{\circ}$, $135^{\circ}$ 굽힘을 취하게 하고 각각의 최대악력과 위팔노근 두께를 전자악력계와 초음파 영상 진단 장비를 이용하여 측정하였다. 그 결과 남자 대학생과 여자대학생 모두 팔굽관절 각도가 $0^{\circ}$일 때 악력이 가장 컸으며, 각도가 증가할수록 악력이 감소하였으나, 통계적으로 유의미한 차이는 없었다(p<.05). 남자대학생과 여자대학생 모두 팔굽관절 각도가 $0^{\circ}$일 때 위팔노근의 두께가 가장 작았으며, 각도가 증가할수록 위팔노근의 두께가 증가하였으며 통계적으로 유의미한 차이가 있었다(p<.05). 본 연구의 결과를 통해 팔굽관절 각도변화가 악력에는 큰 영향을 미치지 않으나, 위팔노근의 두께에는 영향을 미친다는 것을 알 수 있었다.

• Structural Engineering and Mechanics
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• 제48권2호
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• pp.221-239
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• 2013

This paper focuses on a development of strut-and-tie model (STM) to predict the capacity of an improved longitudinal joint for decked bulb-tee bridge systems. Nine reinforced concrete beam/slab specimens anchored by spliced headed bars with different details were tested. Test results were evaluated and compared with an anticipation of the validated STM. The proposed STM provides a lower bound of the ultimate capacity of the joint zone. It shows that the lap length of headed bars has a significant effect on structural behaviors of the improved joint. To develop a full strength joint, the range of the lap length can be determined by the strength and compatibility requirement. Design recommendations to spliced headed bars, concrete strength, as well as lacer bars in the joint zone are proposed for developing a full strength joint.

• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2011년도 추계 총회 및 창립 30주년 기념 심포지엄
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• pp.3-21
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• 2011

Laboratory experiments and numerical simulations using Particle Flow Code (PFC2D) were performed to study the effects of joint separation and joint overlapping on the full failure behavior of rock bridges under direct shear loading. Through numerical direct shear tests, the failure process is visually observed and the failure patterns are achieved with reasonable conformity with the experimental results. The simulation results clearly showed that cracks developed during the test were predominantly tension cracks. It was deduced that the failure pattern was mostly influenced by both of the joint separation and joint overlapping while the shear strength is closely related to the failure pattern and its failure mechanism. The studies revealed that shear strength of rock bridges are increased with increasing in the joint separation. Also, it was observed that for a fixed cross sectional area of rock bridges, shear strength of overlapped joints are less than the shear strength of non-overlapped joints.