• Earthquakes and Structures
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• 제11권4호
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• pp.665-680
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• 2016

This paper focuses on the study of seismic behavior of steel reinforced concrete special-shaped column-beam joints. Six specimens, which are designed according to the principle of strong-member and weak-joint core, are tested under low cyclic reversed load. Key parameters include the steel form in column section and the ratio of column limb height to thickness. The failure mode, load-displacement curves, ductility, stiffness degradations, energy dissipation capacity and shear deformation of joint core of the test subassemblies are analyzed. The results indicate that SRC special-shaped column-beam joints have good seismic behavior. All specimens failed due to the shear failure of the joint core, and the failure degree between the two sides of joint core is similar for the exterior joint but different for the corner joint. Compared to the joints with channel steel truss, the joints with solid web steel skeleton illustrate better ductility and energy dissipation capacity, but the loading capacity and stiffness are roughly close. With the increasing of the ratio of column limb height to thickness, the joints illustrate higher loading capacity and stiffness, better energy dissipation capacity, but worse ductility.

• 한국전문물리치료학회지
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• 제15권1호
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• pp.69-76
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• 2008

This study was designed to determine the effects of swimming and low power laser on rheumatoid arthritis in Sprague-Dawley rats. Rheumatoid arthritis was induced in 36 rats among 48 Sprague-Dawley rats by the subcutaneous injection of .05 $m{\ell}$ Freund's Complete Adjuvant into the right hind paw and .05 $m{\ell}$ Freund's Complete Adjuvant into the right hind knee joint capsule. A second injection was performed by the same method using .1 $m{\ell}$ Freund's Complete Adjuvant per a rat. Arthritic rats were divided into 8 groups: each 1 week and 2 weeks of arthritic swimming, arthritic laser, arthritic case control and normal group. In this study, several experimental tests were performed to determine the concentration of Interleukin-6, the space of the knee joint and the thickness of the hind paw. The concentration of Interleukin-6 and hind paw thickness decreased in the swimming group and laser group as compared to the control group. The space of the knee joint increased significantly after the swimming exercise. Swimming and low power laser therapy positively affect rheumatoid arthritis in rats affect by decreasing the concentration of Interleukin-6 and hind paw thickness, and increasing the space of the knee joint.

• 대한물리치료과학회지
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• 제13권1호
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• pp.7-20
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• 2006

Purpose: This study was to find that what mechanism take effects that was Adjuvant Induced Arthritis in Sprague-Dawley rat and then treated the swimming and low power laser. Methods: Adjuvant Induced Arthritis was induced 24 Sprague-Dawley rat by the subcutaneous injection of a 0.2ml Freund's Complete Adjuvant into the right hind paw and right knee joint. Second injection used of 0.05ml Freund's Complete Adjuvant by same method. Arthritic rat were divided 3 groups; arthritic swimming group, arthritic laser group and case control group. The author performed several experimental tests which were the hind paw thickness, step length, knee joint space, activity of enzyme. Results: Hind paw thickness decreased in swimming and laser group. Left step length and knee joint space increased in swimming and laser. Conclusion: Swimming and low power laser therapy on the Adjuvant Induced Arthritis in rats does effective for the rheumatic arthritis therapy by decrease of hind paw thickness, increase of opposite side step length, increase of activity of albumin and IgG and increase of knee joint space.

• The Journal of Korean Physical Therapy
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• 제18권3호
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• pp.47-58
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• 2006

Purpose: This study was to find that what mechanism take effects that was Adjuvant Induced Arthritis in Sprague-Dawley rat and then treated the swimming and low power laser. Methods: Adjuvant Induced Arthritis was induced 24 Sprague-Dawley rat by the subcutaneous injection of a 0.2ml Freund's Complete Adjuvant into the right hind paw and right knee joint. Second injection used of 0.05ml Freund's Complete Adjuvant by same method. Arthritic rat were divided 3 groups; arthritic swimming group, arthritic laser group and case control group. The author performed several experimental tests which were the hind paw thickness, step length, knee joint space, activity of enzyme. Results: Hind paw thickness decreased in swimming and laser group. Left step length and knee joint space increased in swimming and laser. Conclusion: Swimming and low power laser therapy on the Adjuvant Induced Arthritis in rats does effective for the rheumatic arthritis therapy by decrease of hind paw thickness, increase of opposite side step length, increase of activity of albumin and IgG and increase of knee joint space.

• 터널과지하공간
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• 제14권5호
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• pp.318-326
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• 2004

본 연구에서는 다양한 경계조건에서 충전물을 포함한 절리면의 역학적 특성을 규명할 수 있는 절리면 전단시험 장비를 개발하였다. 그리고 개발된 시험장비를 이용하여 돌출부 경사, 수직응력, 충전물 종류 및 두께변화에 따른 전단시험을 수행하고 충전된 절리면의 전단특성을 고찰하였다. 일정수직응력 조건에서 충전물 종류 및 두께, 돌출부 경사, 수직응력 등을 변화하여 실험을 수행한 바에 의하면 충전된 절리면의 거동과 강도특성은 절리면의 거칠기, 충전물 두께와 종류에 따라 영향을 받는 것으로 나타났으며, 충전물이 없는 절리면과 비교할 때 팽창각이 감소하여 거칠기 영향이 충전물에 의해 감소되는 것으로 나타났다. 그리고 한계두께비는 충전물 종류뿐만 아니라 응력수준, 거칠기에 따라서도 다른 것으로 나타났다.

• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.8-13
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• 2017

The rolled carbon steel plate has anisotropic property in Z-direction(thickness direction). This is induced by cooling rate difference of Z-direction and sulfur which make non-metallic inclusion(MnS) at center line of thickness direction. Z-directional mechanical properties of normal steel plate are not generally specified and it is defined for Z-Quality steel only through tensile test in Z-direction. If Z-quality steel is not applied for cruciform joint, the lamella tearing will be occurred by tensile stress after welding & during operation of the structure. In this research, one equation estimating Z-directional(orthogonal to plate) stress was developed to prevent lamella tearing by welding. This equation deals with plate thickness & joint configuration(eccentricity, angle and curvature). Analyses were done by strain boundary method using sectional FE modeling and FE 3D models are also used for some cases. Designers can predict the possibility of lamella tearing by adequately applying the result and can appropriately minimize the application of Z-quality steel by revising welding design to some extent.

• PNF and Movement
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• 제15권1호
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• pp.51-56
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• 2017

Purpose: The purpose of this study was to examine the effects of the PNF stabilization technique for the hip joint and the bridging exercise on the trunk stabilizer muscles in healthy adults. Methods: Twenty-eight healthy adults were randomly allocated to either a PNF stabilization exercise group (n = 12) or a bridging exercise group (n = 16). The outcome measures included the contraction thickness ratio in the transversus abdominis (TrA), internal oblique (IO), and external oblique (EO), and the TrA lateral slide was assessed during the abdominal drawing-in maneuver using b-mode ultrasound. The researcher measured the abdominal muscle thickness of each participant before the therapist began the intervention and at the moment that the intervention was applied. Between-group comparisons were performed using the Mann-Whitney U test. The level of statistical significance was set at 0.05. Results: The PNF intervention program showed a significant increase in the trunk stabilizer muscle. The percentage of change in the TrA thickness showed a significant interaction between intervention. However, there were no significant differences in the IO and EO between the two groups. Conclusion: The PNF stabilization technique for the hip joint can be used effectively to improve the IO and TrA muscles in healthy adults.

• 한국정밀공학회지
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• 제20권7호
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• pp.171-176
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• 2003

In this study, stress analysis using Boundary Element Method (BEM) was carried to investigate stress distribution in the brazing joint between a Hardmetal and a HSS. The two models were proposed to analyze the stress singularity in the interfaces of the brazing joint. The material type, thickness of the filler metal and the length of the vertical brazing adhesive are considered in the BEM analysis. As results, the peak point of the stress is founded to be in the lower interface of the brazed joint. It should be noted that the maximum stress of the peak point is being affected by the thickness and length of the brazing joint.

• Journal of Welding and Joining
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• 제12권1호
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• pp.80-93
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• 1994

The microstructure and fractography of the friction welded joint of Al to Cu have been investigated in order to understand the formation of intermetallic compounds and their effects on the failure in tensile test of the joint. The variation of welding pressure did not affect significantly the tensile strength of joint. However, the tensile strength of joint decreaed as welding time increased. The thickness of reaction layers of welded joints was several micro-meters and mainly composed of intermetallic compounds of $CuAl_2$, $Cu_9Al_4$ and Al+$CuAl_2$. The thickness of $CuAl_2$, $Cu_9Al_4$ was increased with welding time. However, $CuAl_2$ was gradually changed to $Cu_9Al_4$ which caused the decrease of tensile strength . Even though the morphology of fractured surfaces depended upon the welding time, the failure occurred along $CuAl_2$ intermetallic compound itself or between $CuAl_2$ and $Cu_9Al_4$ in most cases.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 춘계학술발표대회 개요집
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• pp.223-225
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• 2005

In order to demonstrate the friction stir weldability of the Al 6061 T-6 unequal thickness joint and determine optimum welding parameters, the relations between welding parameters and properties of the joints have been studied in this paper. The experimental results showed that the tensile properties of the joints are affected by the welding heat inputs and tool shape. In this study, the maximum ultimate strength of the as-welded joint is equivalent to 78% and 18hour aged joint is equivalent to 93% that of the base metal. Though the voids-free joints are fractured at the thermally affected zone on the advancing side, the fracture occurs at the weld center when the void defects exist in the joints.