• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1290-1295
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• 2014

In this paper, various configurations of octagonal wound transformer core topology, which has previously proved advantages on conventional wound cores, are studied. Each configuration has different joint types and different placement of joint zones on the core. Magnetic flux distributions and power losses of each configuration are analyzed and compared. Comparisons are based on both 2D&3D finite element simulations and experimental studies. The results show that, joint types and their placements on the core cause local flux accumulations and dramatically affect power loss of the core.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.2
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• pp.113-121
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• 2013

Objectives : The objective of this study is to report the effect of Traditional Korean medical therapy and core exercise on osteoarthritis of knee joint by observing a clinical case study. Methods : Patient with a diagnosis of osteoarthritis of knee joint, was treated by acupuncture, herb medicine, physical theraphy and core exercise. Results : After treatment, Visual Analogue Scale(VAS), Korean version of the Western Ontario and McMaster Universities(KWOMAC), Pain Rating Score(PRS) were reduced from 5 to 2, from 25 to 16, from 55 to 27, and CENTAUR test results were improved. Conclusions : This study showed that Traditional Korean medical therapy and core exercise has meaningful effect on osteoarthritis of knee joint, and more researches should be followed.

• Earthquakes and Structures
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• v.11 no.4
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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.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1205-1210
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• 2005

The behavior of rock mass and solute(e.g. groundwater, radioactivity) flow in fractured rock can be directly influenced by joint roughness. The characteristics of joint roughness is also a main factor for the rock classification(e.g. RMR, Q system) which is usually used in tunnel design. Nevertheless, most of JRC estimation has been carried out only by the examination with the naked eye. This JRC estimation has a lack of objectivity because each investigator judges JRC by his subjective opinion. Therefore, it will be desirable that the assessment of JRC is performed by a numerical analysis which can give a quantitative value corresponding to the characteristics of a roughness curve. Meanwhile, roughness curves for joint surfaces which are observed in drill cores have been obtained only along linear profiles. Although roughness curves are measured in the same joint surface, they can frequently show diverse aspects in a standpoint of roughness characteristics. If roughness curves can be measured along the elliptical circumferences of joint surfaces from core scanning images or Televiewer images, they will certainly be more comprehensive than those measured along linear profiles for roughness characteristics of joint surfaces. This study is focus on dealing with (1) extracting automatically roughness curves from core scan image or Televiewer image, (2) improving the accuracy of quantitative assessment of JRC using fractal dimension concept.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1207-1208
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• 2006

We developed the copper core ball electroplated with Sn-Ag-Cu of the eutectic composition which used mostly as Pb free solder ball with high reliability. In order to search for the practicality of this developed copper core ball, the evaluation was executed by measuring the initial joint strength of the sample mounted on the substrate and reflowed and by measuring the joint strength of the sample after the high temperature leaving test and the constant temperature and the humidity leaving test. This evaluation was compered with those of the usual other copper core balls electroplated with (Sn,Sn-Ag,Sn-Cu,Sn-Bi) and the Sn-Ag-Cu solder ball.

• Structural Engineering and Mechanics
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• v.82 no.6
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• pp.801-812
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• 2022

To better promote the development of fabricated buildings, this paper studies the seismic behavior of precast concrete beam-column bolted joint under vertical low cyclic loading. The experimental results show that cracks appear in the beam-column joint core area. Meanwhile, the concrete and the grade 5.6 bolts are damaged and deformed, respectively. Specifically, the overall structure of the beam-column joint remains intact, and the bolts have good energy dissipation capacity. Based on the experimental study, a new method of beam-column bolted connection is proposed in simulation analysis. The simulation results show that the bolts deform in the core area of the new beam-column joint, which enhances the concrete shear capacity legitimately and protects the T-end of the beam against shear failure. To summarize, both the experimental joint and the simulated joint prolong the service life by replacing the bolts under the seismic loading. The research results provide a reference for applications of the fabricated beam-column joint.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.178-178
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• 2008

This paper presents an efficient approach for simulating the loss of the laminated core joints in power transformers. Two laminated core models, with the same material and joint type but different leg length, are established for validating the specific total loss inside the joint region.

• Proceedings of the Korea Concrete Institute Conference
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• 1990.04a
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• pp.61-65
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• 1990

The purpose of this study was to investigate the effect of Bent-up Bars in Beam-Column Joint with High-Strength Concrete up to 800 kg/$\textrm{cm}^2$. 5 specimens were tested under reversed cyclic loadings. The primary variables were the number of the Bented Bars with Joint Core, compressive strength and loading patterrns. The results showed that bent-up bars in beam-column joint prevented crack from extending into core but the failure was concreterated at the face of beam-column joint. Thus shear stress constant value(Г) should be revised for High Strength Concrete Beam-Column Joint with Bent-up Bars.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.95-102
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• 2023

The purpose of this study was to investigate the effect of 8 weeks of core training on dynamic posture control, lower extremity injury and proprioceptive joint position sensory in ski athletes. Twenty subjects participated in this study and were randomly divided into two groups : exercise group (Ex=10) and control group (Con=10). The core training program consisted of a bench, a sideways bench, a plank, a side bridge, and a supine bridge, and was conducted three times a week for 8 week. The dynamic posture control had a significant effect on the left and right postero-medial reach, and the lower extremity criterion test had a significant effect on the left and right composite scores. In addition, there was a significant decrease in the proprioceptive joint position sense at 15°of the left leg and 45°. In conclusion, 8 weeks a core training have been shown to improve skiers' dynamic posture control, lower extremity injury and proprioceptive joint position sensory.

• Earthquakes and Structures
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• v.4 no.4
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• pp.429-449
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• 2013

Current Design Codes for Reinforced Concrete (RC) interior beam-column joints are based on limited experimental studies on the seismic behavior of eccentric joints. To supplement existing information, an experimental study was conducted that focused on the effect of eccentricity of the deeper beams with respect to the shallow beams. A total of eight one-third scale interior joints with beams of different depths were subjected to reverse cyclic loading. The primary variables in the test specimens were the amount of joint transverse reinforcement and the cross section of the shallow beams. The overall performance of each test assembly was found to be unsatisfactory in terms of joint shear strength, stiffness, energy dissipation and shear deformation. The results indicated that the vertical eccentricity of spandrel beams in this type of joint led to lower capacity in joint shear strength and severe damage of concrete in the joint core. Increasing the joint shear reinforcement was not effective to alter the failure mode from joint shear failure to beam yielding which is favorable for earthquake resistance design, whereas it was effective to reduce the crack width at the small loading stages. Based on the observed behavior, the shear stress of the joint core was suggested to be kept as low as possible for a safe and practical design of this type of joint.