• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.3-7
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• 1996

Metal Matrix Composite(MMC) material of 30% SiC particulate based on A1 matrix was machined by drilling and Electrical Discharge Machining (EDM) processes. When drilling process was executed, surface fracture due to brittle property near the bottom was found. It was also found the possiblity of difficult shape of EDM process for MMC material, but few the research about basic EDM characteristics. Material Removal Rate(MRR) was examined for different conditions and the surface morphology was evaluated by roughness values and Scanning Electron Microscopy(SEM) research. The higher the current is, the more MRR was obtained but the higher MRR was showed around 0.45 duty factor. The average roughness of EDMed surface was slightly changed with increased pulse current and increases with duty factor. The SEM photographs of EDMed surface showed recast region after melting.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.600-603
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• 2008

Tire is one of the key components in automobiles. Especially, most vibrations during driving are resulted from the im-balancing of tire-wheel composites. In this study, this problem has been solved by using glass beads as a balancing material. In addition, the glass beads are coated using several materials to reduce the tendency of aggregation of glass beads.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.1
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• pp.81-88
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• 2010

Purpose : The purpose of this study was to investigate the relationship between postural sway and asymmetric weight-bearing for fall prevention in patients with stroke. Methods : Fifty-three individuals with hemiplegic stroke and 57 healthy older adults c

• The Korean Journal of Pain
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• v.4 no.1
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• pp.47-50
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• 1991

Bells palsy is a usually innocuous but psychologically distressing disease. The majority of cases are of the so-called idiopathic type, the etiology of which is unknown. This 52 year-old female patient was treated with repeated stellate ganglion bupivacaine blocks, acupuncture and transcutaneous electric nerve stimulation, with return of function. In our case studies, using thermographic images to diagnosis and to evaluate objective assessment of treatment of Bells palsy, we observed the correlation between neurologic symptoms and thermographic image.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.27-35
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• 2022

A systematic support system that develops technology support policies for SMEs (Small and Medium sized Enterprises) and solves technical problems faced by SMEs will increase the productivity and competitiveness of SMEs. To this end, it is necessary to identify the types and level of technology required for SMEs, and to find ways to utilize the technologies possessed by government-funded research institutes leading technology development. It is important to develop a new production technology and to establish a cooperation system between SMEs and government- funded research institutes to solve various pending problems.

• Korean Journal of Materials Research
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• v.11 no.12
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• pp.1057-1062
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• 2001

We investigated the change of mechanical properties for TiNi shape memory alloy by heat treatment. 6061Al matrix composites with TiNi shape memory alloy as reinforcement were fabricated by vacuum casting. TiNi alloy has the maximum tensile strength at 673K treated and there is no change of tensile strength and hardness at 448K treated. The composites, prepared by vacuum casting, showed good interface bonding by vacuum casting. It was about 3$\mu\textrm{m}$ of thickness of the diffusion layer. Tensile strength of the composite was in higher than that of 6061Al alloy as increased value of about 70MPa at room temperature and about 110MPa at 363K. We thought that the increase of the tensile strength at 363K was due to reverse transformation of the TiNi shape memory alloy.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.387-395
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• 2013

PURPOSE: The purpose of the present study was to investigate the effect of the training using Pedalo equipment on balance function in post-stroke patients. METHODS: The present study was case-series. Ten post-stroke patients participated in the study. Participants performed the training using Pedalo equipment. The training using four Pedalo equipment lasted 30 minutes, 3 times a week for 6 weeks. Force platform, Berg Balance Scale(BBS), and Timed Up and Go(TUG) test were used to assess balance ability before and after training. RESULTS: After training using Pedalo equipment, there were significantly improved on path length and sway velocity of post-stroke patients in the both of eye open and - close conditions comparing with baseline. Also, on the BBS and TUG, there were significant improvements after training. CONCLUSION: The results of this study showed that the training using Pedalo equipment may be effective on improving the balance ability in the post-stroke patients. Through this study, we were able to confirm the potential of training using Pedalo equipment as an intervention in the rehabilitation of post-stroke patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.275-282
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• 2002

Tensile residual stress happen by difference of coefficients of thermal expansion between fiber and matrix is one of the serious problems in metal matrix composite(MMC). In this study, TiNi fiber was used to solve the tensile residual stress as the reinforced material. TiNi fiber improves the tensile strength of composite by occurring compressive residual stress in matrix using shape memory effect of it. Pre-strain was added to generate compressive residual stress inside TiNi/A16061 composite. It was also evaluated the effect of compressive residual stress corresponding to pre-strains variation. AE technique was used to clarify the microscopic damage behavior at high temperature and the effect of pre-strain difference of TiNi/A16061 shape memory alloy composite.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.72-78
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• 2002

Thermomechanical behavior and mechanical properties of A16061 matrix composite with shape memory alloy(SMA) fiber are studied by using fnite element analysis(FEA). The smartness of the SMA is given due to the shape memory effect of the TiNi fiber which generates compressive residual stress in the matrix material when healed after being prestrained. In this paper, an analytical model is assumed two dimentional axisymetric model of one fiber and around the matrix. To evaluate the strength of composite usig FEM, the concept of smart composite was simulated on computer. The Shape memory effect(SME) simulation is very difficult using FEM because of the nonlinear analysis and the elastic plastic analysis. Thus, in this paper, the FEA was carried out at two critical temperature conditions; room temperature and high temperature(363K). The analysis is compare the finite element analysis result with the test result for the analysis validity.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.181-189
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• 2020

As production, distribution, consumption and processing increase with the development of industrial societies, the importance of resource depletion and environmental problems is increasing day by day. This has led to increased research and interest in remanufacturing that can satisfy both environmental and economic aspects. Currently, the remanufacturing industry is progressed in Korea with automobile parts with as the central figure, and it needs to be expanded into various areas. In this study, the failure type analysis and FMEA were performed on the hydraulic pumps used in construction and industrial sites for the development of the standard remanufacturing process plan, and the actual disassembly and reassembly process was carried out. Remanufacturing products were manufactured through the analysis contents and drawing process, performance tests were conducted in accordance with RS B1501 criteria to evaluate performance, and all of these products passed the test criteria.