• Journal of muscle and joint health
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• v.4 no.2
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• pp.221-237
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• 1997

In an attempt to measure effects of the Programmed Resistance Exercise on the daily performance of patients with rheumatoid arthritis, a quasi-experiment ; non-synchronised control group pre-post-test, was carried out for 8 weeks : from June 3 to November 29, 1996. 25 for the experimental group and 26 for the control group were conveniently sampled among registered out-patients on rheumatoid arthritis clinic of Anam Hospital, Korea University Medical Center. The programmed experimental resistance exercises were carried out by the experimental group five times a week for eight weeks. Before and after experiments, level of functional task performance, functional disability, joint mobility, ESR, CRP, self-efficacy and family support were measured and statistically analysed. The results of the analysis of the effects on the Programmed Resistance Exercise are as follows : 1. A statistically significant post-test effects on functional task performance were revealed : 1) the experimental group climbed up and down the 10 steps of the stairs significantly faster than the control group(P=0.0001). 2) the experimental group walked 100 m significantly faster than the control group (P=0.0000). 3) After the experiment, the experimental group could sit down and get up from chairs with no armrest as low as 30cm, 40cm, 50cm on their on, with no assistance as opposed to the control group who could not sit down and get up from such low chairs (P=0.0084). 4) the experimental group lifted 0-15 kg object up to their own heights with no specific strain than the control group (P=0.0000). 2. A significant reduction in the functional disabilities was revealed in the experimental group(P=0.0017). 3. A notable incresement of the joint mobility was revealed in the experimental group. 4. A decrease in the ESR in both the experimental and the control groups was noticed, however, the difference was not statistically significant (P=0.9546). 5. The CRP of both the experimental and control groups decreased with no significant difference (P=0.6022). 6. The self-efficacy increased significantly in the experimental group(P=0.0042), however, no significant effect of self-efficacy on the actual practice of the program was noticed. 7. The family support revealed to be significantly higher in the experimental group (P=0.0013), however, the effect of the family support on actual practice of the program revealed not significant. Judging from the results of these experiments, the resistance exercise program not only improves the functional capacity of rheumatoid arthritis, but also diminishes their functional disabilities and has a great influence on increasing their joint mobility, self-efficacy, and family support. Concluding, in promoting the daily performance of rheumatoid arthritis, the resistance exercise program would be an appropriate nursing intervention.

• Steel and Composite Structures
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• v.32 no.1
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• pp.111-126
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• 2019

This paper deals with experimental investigation and modeling of the static behavior of a novel RCS beam-column exterior joint. The studied joint detail is a through-column type in which an H steel profile totally embedded inside RC column is directly welded to the steel beam. The H steel profile was covered by two supplementary plates in the joint area in order to avoid the stirrups resisting shear in the joint area. Two full-scale through-column-type RCS joints were tested under static loading. The objectives of the tests were to examine the connection performance and to highlight the contribution of two supplementary plates on the shear resistance of the joint. A reliable nonlinear 3D finite element model was developed using ABAQUS software to predict the response and behavior of the studied RCS joint. An extensive parametric study was performed to investigate the influences of the stirrups, the encased profile length and supplementary plate length on the behavior of the studied RCS joint.

• Composites Research
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• v.34 no.5
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• pp.317-322
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• 2021

When a complex load such as torsion, low-speed impact, or fatigue load is applied, the properties in the thickness direction are weakened through microcracks inside the material due to the nature of the laminated composite material, and delamination occurs. To prevent the interlaminar delamination, various three-dimensional reinforcement methods such as Z-pinning and stitching, and structural health monitoring techniques that detect the microcrack of structures in real time have been continuously studied. In this paper, the single-lap joints with I-fiber stitching process were manufactured by a co-curing method and their strengths and failure detection capability were evaluated. AE and electric resistance method were used for detection of crack and failure signal and electric circuit for signal analysis was manufactured, and failure signal was analyzed during the tensile test of a single-lap joint. From the experiment, the strength of the single lap joint reinforced by I-fiber stitching process was improved by about 44.6% compared to the co-cured single lap joint without reinforcement. In addition, as the single-lap joint reinforced by I-fiber stitching process can detect failure in both the electrical resistance method and the AE method, it has been proven to be an effective structure for failure monitoring as well as strength improvement.

• Journal of Welding and Joining
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• v.27 no.5
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• pp.49-54
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• 2009

Recently, a demand of ferritic STS is increasing rapidly in automobile exhaust system. Exhaust manifolds are the part nearest to the engine so that the material is exposed to high temperature exhaust gas. Excellent heat resistant properties, especially high temperature strength, thermal fatigue resistance and high corrosion resistance are necessary for these parts. STS429L contains 15 weight percent of Cr and low Mo, so has good price competitive. And it has excellent high temperature strength and corrosion resistance, so receives attentions as material that applying to exhaust manifold. In tensile test of lap joint welded STS 429L, most of specimens are failed in base metal, but occurs brittle fracture in weld metals at some specimens in the face of good welding conditions. In the process of tensile test, lap joint welded STS429L specimens are transformed locally. The brittle fracture occurs that local transforming area exists in weld metals. But, butt welding specimens made by same materials showed ductile fracture in tensile test and bending test. In this study, suppose the reason of brittle fracture is in the combined local transform and tensile stress, through analysis of bead geometry, evaluate geometrical factor of brittle fracture in lap joint welded STS429L.

• Steel and Composite Structures
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• v.22 no.5
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• pp.1019-1038
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• 2016

The use of high-strength concrete (HSC) in precast concrete segmental bridges (PCSBs) can minimize the superstructure geometry and reduce beam weight, which can accelerate the construction speed. Dry joints between the segments in PCSBs introduce discontinuity and require special attention in design and construction. Cracks in dry joints initiate more easily than those in epoxy joints in construction period or in service. Due to the higher rupture strength of HSC, the higher cracking resistance can be achieved. In this study, shear behavior of dry joints in PCSBs was investigated by experiments, especially focusing on cracking resistance and shear strength of HSC dry joints. It can be concluded that the use of HSC can improve the cracking resistance, shear strength, and ductility of monolithic, single-keyed and three-keyed specimens. The experimental results obtained from tests were compared with the AASHTO 2003 design provisions. The AASHTO 2003 provision underestimates the shear capacity of single-keyed dry joint C50 and C70 HSC specimens, underestimates the shear strength of three-keyed dry joint C70 HSC specimens, and overestimates the shear capacity of three-keyed dry joint C50 HSC specimens.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.237-242
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• 1993

Precast concrete panel buildings are designed to tracsmit shear forces through the joint between the reinforced concrete panels. The shear strength is partly provided by the resistance to sliding at the interface between the precast and in- situ concrete and partly by the dowel action of the reinforcement crossing the joint. The shear resistance to sliding is largely dependent on the shapes and configurations of vertical joints and the vertical loads of horizontal joints. In this paper, the shear strength by the difference of relative strength between panel and joint, the effect of reinforcement, and the effect of vertical load are considered.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.153-159
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• 2014

This research reviewed the joint and duration characteristics depending on the surface treatment condition and lap spliced length in the PET film jointing method using the high hardness liquid material. As a result, the corona discharge treatment was improved to the contact angle, joint tensile strength, and joint peel resistance compared to non-treatment. Particularly, a surface treatment E (Corona discharge + Primer + PU bond + Polyester fabric) turned out to the best, and especially when the lap spliced length is longer than 15mm, stable joint performance was secured under the long term deterioration treatment of 16 weeks. Thus, the joint is considered to be applicable as the water-proof material.

• Korean Journal of Metals and Materials
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• v.50 no.10
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• pp.785-792
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• 2012

A new flip chip structure consisting of interlocking joints locally surrounded by non-conductive adhesive was investigated in order to improve the contact resistance characteristics and prevent the parasitic capacitance increase. The average contact resistance of the interlocking joints was substantially reduced from $135m{\Omega}$ to $79m{\Omega}$ by increasing the flip chip bonding pressure from 85 MPa to 185 MPa. Improvement of the contact resistance characteristics at higher bonding pressure was attributed not only to the increased contact area between Cu chip bumps and Sn pads, but also to the severe plastic deformation of Sn pads caused during formation of the interlocking-joint structure. The parasitic capacitance increase due to the non-conductive adhesive locally surrounding the flip chip joints was estimated to be as small as 12.5%.

• Wind and Structures
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• v.29 no.5
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• pp.361-369
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• 2019

The modal frequency responses of adhesive bonded T-joint structure have been analyzed numerically and verified with own experimental data. For this purpose, the damped free frequencies of the bonded joint have been computed using a three-dimensional finite element model via ANSYS parametric design language (APDL) code. The practical relevance of the joint structure analysis has been established by comparing the simulation data with the in-house experimental values. Additionally, the influences of various geometrical and material parameters on the damped free frequency responses of the joint structure have been investigated and final inferences discussed in details. It is observed that the natural frequency values increase for the higher aspect ratios of the joint structure. Also, the joint made up of Glass fiber/epoxy with quasi-isotropic fiber orientation indicates more resistance towards free vibration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.221-222
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• 2023

In this study, the performance evaluation of waterproof sealant materials applied to the outer wall of PC apartment houses was conducted. The sealant for PC members must have resistance to movement, and since it is exposed to outside air, weather resistance and water resistance are required.