• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.58-64
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• 2003

A mechanical press joining was investigated in ender for joining A1-5052 sheets for automobile body weight reduction. Static tensile and fatigue tests were conducted using tensile-shear specimens for evaluation of fatigue strength of the joint. During Tox joining process for A1-5052 plates, using the current sheet thickness and punch diameter, the optimal applied punching force was found to be 32 kN under the current joining condition. For the static tensile-shear experiment results, the fracture mode is classified into interface fracture mode, in which the neck area fractured due to influence of neck thickness, and pull-out fracture mode due to influence of plastic deformation of the joining area. And, during fatigue tests for the A1-5052 tensile shear specimens, interface failure mode occurred in the region of low cycle. The fatigue endurance limit approached to 6 percents of the maximum applied load, considering fatigue lifetime of $2.5\times10^6$ cycles.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1068-1073
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• 2010

A welding neck flange is widely used for an interconnection between pipes. It is produced by a hot forging process, and required high yield strength under the high pressure condition, like a deep-sea. Generally, to increase yield strength, a increasing of carbon content is used, however a carbon content of welding neck flange is limited to 0.47. So, in this study, a strengthening by grain refinement without changing carbon content is used to increase yield strength. Taguchi method and FEM are used for the optimization of forging process and the experiment for the yield strength of the prototype with the optimal forging process is performed for validity.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.59-64
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• 2008

The aims of this study were to compare and analyze two types of deep cervical flexion exercises, craniocervical flexion and cervical flexion, and to ascertain their relative effects on neck and shoulder pain and functional improvement. The participants of the study were individuals who work in sedentary jobs in an office environment. 54 appropriate subjects were chosen and randomly divided into two groups: one group underwent a craniocervical flexion exercise program and the other a cervical flexion exercise program. The six week exercise program consisted of home exercises performed by each subject five times a week and education once a week. Neck-shoulder pain, muscle strengthening, cervical alignment were measured prior to commencement of the exercise programs and again after six weeks. At completion of the six week, both exercise programs decreased neck pain (p<.05). Forward head postures were reduced, and the craniocervical flexion exercise program was more effective in reducing forward head posture (p<.05). The maximum muscle strength and 50% of maximum muscle strength maintaining time of the deep cervical flexor muscles were significantly increased. There were no significant changes of the cervical lordotic curve. The results of this study showed deep cervical flexion exercise was effective in the treatment of neck and shoulder pain, however craniocervical flexion exercise was more effective than cervical flexion exercise.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.752-760
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• 2000

Mechanical press joining has been used in sheet metal joining processes because of its simple process and possibility of joining dissimilar metals, such as steel and aluminum. The strength of mechanical press joining varies with joining conditions. The optimum joining conditions considering tensile-shear and peel-tension strength have to be established to assure the reliability in the joining strength. Therefore, optimization of joining conditions has been investigated for improving joining strength of sheet metal. It is possible to obtain optimum strength from improvement on the joining strength of peel-tension mechanical press joint under multiaxial stress states.

• Journal of International Academy of Physical Therapy Research
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• v.8 no.2
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• pp.1142-1145
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• 2017

The purpose of this study was to examine the effect of kinematic taping on respiratory muscle strength in smokers. Twenty - five university students who smoke were involved in the study. All participants were applied to kinematic taping to breathe deeply again. Subjects sit on their backs straight up and place their hands on their thighs. Tape 1 is applied from the lower prominent neck vertebrae(seven cervical vertebra) inward and downward, past shoulder blade, around ribs to the lower tip of sternum. Tape 2 extends to the lower, outer edge of shoulder blade, around ribs to the lower tip of sternum. Respiratory muscle strength was measured with Micro Mouth Pressure Measurement before and after taping. The application of kinematic taping significantly improved the inspiratory and expiratory muscle strength (p<.05). These findings suggest that kinematic taping effective in improving respiratory muscle strength and deep breathing.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.375-378
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• 2003

In the present study, a new approach to predict the strength of sintered materials has been carried out and a new framework combining neck growth model and ideal pore model has been established based on the results of tensile tests on powder injection molded specimens with the various porosity. Powder injection molding (PIM) uses the shaping advantage of injection molding but is applicable to metals and ceramics. PIM delivers structural materials in a shaping technology previously restricted to polymers. 17-4 PH stainless steel powders with average diameters of 10 $\mu\textrm{m}$ were injection-molded into flat tensile specimens sintered at the various temperatures ranging from 900 to 1350$^{\circ}C$ for 1h. The relationships between strength and porosity were applied to the experimental results and verified.

• Transactions of Materials Processing
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• v.7 no.6
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• pp.530-538
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• 1998

Elimination of the heat treatment process is very important in automation of metal forming since controlling heat treatment by computer has many difficulties and it has bottle neck problem. non-heat-treated steels materials which are not in need of heat treatment have been developed for cold forging. However to apply non-heat-treated steel to structural parts. it is necessary to prove reliability of mechanical properties. In order to define the reliability of mechanical properties we have investigated microstructure, hardness, the tensile strength compressive strength and tensile fatigue strength for both steels. Considering the results of high cycle fatigue test for both specimen the characteristics of non-heat-treated steel are decided on the yield strength, It has same tendency for heat-treated steel. Therefore non-heat-treated steel which has the appropriate yield strength may be applied in cold forging.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.3
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• pp.23-30
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• 2023

Background: The purpose of this study was to investigate the effects of joint mobilization and muscle strengthening exercises on neck function, range of motion, and muscle tone in patients with forward head posture. Methods: A total 32 subjects were divided into muscle strengthening exercise (n=16) and joint mobilization (n=16) who met the diagnostic criteria for the forward head posture, and the study method used the neck disability index (NDI) and BPM Pro to compare the range of motion. Results: As a result of the study, there was no significant difference between each group, and when looking at the differences before and after each group, there was a significant difference in neck pain in both groups. There was a significant difference in muscle tension in the joint mobilization group, but there was no significant difference in the muscle strengthening exercise group. In the range of joint mobilization, there was a significant difference in the range of left joint mobilization of the joint mobilization group, there was no significant difference in the range of right joint mobilization, and there was no significant difference in the range of joint mobilization of the muscle strengthening exercise group. Conclusion: The above results revealed that joint mobilization and muscle strengthening exercises were effective on neck function, range of motion, and muscle tone in forward head posture patients.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.285-292
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• 2007

This study was developed the metallic plate for fixation in the femur fracture for the orthopedic region and rigid fixation with plates has a firm place in fracture treatment. Most plates can be used for rigid as well as biological and dynamical fracture fixation. The device's designation and sizing has a specific with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. Short plate have a wrapping of femur and long plate have to preserve a pole of femur. The bending strength of the curved metallic long plate has to evaluate a 11,000N and The bending strength of the curved metallic short plate has to evaluate a 6,525N. The tensile stress through to press a plate is $1573N/m^2\;and\;1539N/m^2$. The device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.302-308
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• 2020

Objective: The endurance and strength of deep neck flexor (DNF) muscles have a major role on the function and stability of the cervical spine. In recent years, there has been a lack of research that have investigated the muscle tone of the superficial neck muscles. The purpose of this study was to examine the relationship of between contraction ratio of the DNF and sternocleidomastoid (SCM) muscles, DNF endurance, and muscle tension of the neck muscles. Design: Cross-sectional study. Methods: Forty-seven subjects (male=20, female=27) participated in this study. The muscle tone of the upper trapezius (UT), SCM, and suboccipital (SO) muscle was measured using a contact soft tissue tone-measuring instrument. For the contraction ratio of the SCM and longus colli muscle, the thickness of the relaxation and maximum contraction state of the SCM and longus colli muscles were assessed using a diagnostic ultrasound measuring instrument and a pressure biofeedback unit. The deep neck flexor endurance test (DNFET) was performed in a cranio-cervical flexion posture. The correlations between the measured variables were investigated. Results: The relationship between the DNFET and SO tone showed a significant negative correlation (p<0.05). The relationship between the DNFET and contraction ratio showed a significant positive correlation (p<0.01). There was no significant correlation between the DNFET and SCM and UT tone. Conclusions: This study confirmed that there is a relationship between DNF endurance, DNF activation, and SO tone. The information on the results of this study may be used as a reference that can be actively applied in the clinical environment.