• The Journal of Korean Physical Therapy
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• v.25 no.3
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• pp.136-142
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• 2013

Purpose: The application of transcutaneous electrical nerve stimulation (TENS) is beneficial for joint movements, inhibition of spasticity, and the improvement of walking ability in patients with chronic hemiplegia. This study aimed to identify the effect of the application of TENS to the knee extensor on the affected side with respect to postural-sway distance and velocity during the sit-to stand movement. Methods: We included 19 patients with post-stroke hemiplegia in this study. They underwent measurements during the sit-to stand movement on a force plate with 5 different stimulation dosages applied over 7 s:No TENS, high-frequency and high intensity TENS, high-frequency and low intensity TENS, low-frequency and high intensity TENS, and low-frequency and low intensity TENS The 5 different condition were administered in random order. Results: The group that received TENS application exhibited a significant decrease in path length and average velocity of center of pressure (COP) displacement compared with the group that did not receive TENS application. TENS dosage at low frequency (3Hz) and high intensity yielded a significant decrease in path length, average velocity, mediolateral distance and anteroposterior distance of COP displacement (p<0.05). Conclusion: Our results demonstrated the effectiveness of the application of low-frequency TENS on STS performance. These findings provide useful information on the application of TENS for the reduction of postural sway during the sit-to-stand movement after stroke.

• Journal of Korean Society of Steel Construction
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• v.12 no.4 s.47
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• pp.339-350
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• 2000

The objective of this study is to investigate the structural behavior of the beam to column connection with reformed T-stubs and to ascertain the application of semi-rigid connection with reformed T-stubs to middle high rise buildings. The tests of steel frame using semi-rigid connections with reformed T-stub and existing T-stub were performed under cyclic loading condition. Finite element analysis was also carried out and the results of FEM were compared with results of tests. The thickness of reformed T-stub and the distance of bolt were used for parameters in the analysis. The structural behaviors of reformed T-stub were understood qualitatively and the possibility of application of semi-rigid connections with reformed T-stubs was ascertained.

• Journal of Welding and Joining
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• v.26 no.6
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• pp.54-58
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• 2008

Laser welding with AZ61 filler wire was carried out to improve formability though reduction of porosity and formation of under fill bead. Optimum welding condition and mechanical properties of butt joint for $400{\times}500{\times}1.3mm$ magnesium sheets were studied. Optimal welding conditions of laser power, welding speed, and defocusing length are 1000W, 3m/min, and 2mm, respectively. Results of tensile test indicated that both tensile strength and elongation of specimens welded with filler wire were improved at room temperature because of reduction of porosity and under-filled bead formation in addition to the precipitation hardening and microstructure refinement by Al-Mn and Mg-Al-Zn precipitates. At elevated temperature of $200{\sim}350^{\circ}C$, fracture location of tensile specimen was shifted from weld metal to base metal, indicating less softening of weld metal than base metal.

• Journal of KSNVE
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• v.5 no.1
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• pp.107-115
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• 1995

An analytical model for drillstring axial vibration is proposed. The drillstring is modelled as an equivalent stepwise uniform bar, and the bottom boundary is modelled asa spring and a damper which depend on WOB(weight on bit). The effect of tool joints and the effect of surrounding layers, such as mud and formation, are evaluated theoretically. To investigate the bottom boundary condition, a forced axial vibration testing technique was developed and the tests with a typical drillstring were performed at various WOB's. The results show good agreement with theoretical results. An important conclusion is that the flexibility of the bottom rock must be included in order to predict resonant frequencies of the drillstring axial vibration.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.249-257
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• 1999

A three dimensional finite model of a human neck has been developed in an effort to study the mechanics of cervical spin while subjected to vertical impact. This model consisting of the vertebrae from C1 through C7 including posterior element and ligaments was constructed by 2mm thick transverse CT cross-sections and X-ray film taken at lateral side. Geometrical nonlinearity was also considered for the large deformation on the disc. ABAQUS package was used for calculation and its results were verified comparing with responses of a model under static loading condition with published in-vitro experimental data. There were more cervical fracture in the restrained (compression) mode than in the nonrestrained (flexion-compression and extension-compression) mode. Upper cervical(C1-C2) injuries were observed under compression-extension modes, while lower cervical injuries occurred undjer compression-flexion modes. Posterior ligament distraction without bony damage at the upper cervical spin(C1-C2) were observed secondary to C5-C7 trauma in compression-flexion modes.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.96-111
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• 1995

A bellows is a component installed in the automobile exhaust system to reduce the impact from an engine. It's stiffness has a great influence on the natural frequency of the system. Therefore, it must be designed to keep the specified stiffness that requires in the system. This study present the finite element analysis of U-typed bellows using a curved conical frustum element and the shape optimal design with specified stiffness. The finite element analysis is verified by comparing with the experimental results. In the shape optimal design, the weight is considered as the cost function. The specified stiffness from the system design is transformed to equality constraints. The formulation has inequality constraints imposed on the fatigue limit, the natural frequencies, the buckling load and the manufacturing conditions. A procedure for shape optimization adopts a thickness, a corrugation radius, and a length of annular plate as optimal design variables. The external loading conditions include the axial and lateral loads with a boundary condition fixed at an end of the bellows. The recursive quadratic programming algorithm is selected to solve the problem. The result are compared with the existing bellows, and the characteristics of the bellows is investigated through the optimal design process. The optimized shape of the bellows are expected to give quite a good guideline to the practical design.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.67-74
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• 1979

This survey was carried out to grasp the actual condition of a power tiller utilization . Now, the power tiller has become the leading machinery in the field of agriculture throughout the country . Two hundred farm houses, located in the provincial districts of Kimcheon and kum0rung, hav etaken part in the survey from October 1, 1976 to September 30, 1977. The results are summarized as follows . 1. The average size of cultivated land of a farm household in the districts surveyed was 1.77ha which was bigger than that of whole country. And the average age of power tiller drivers was analyzed in which only 105 of total drivers was on their 30's. 2. Distribution of a power tiller utilization was appeared to be 34.4% for transporting , 24% for tilling , 23% for pumping , 11.5% for threshing and 6.6% for spraying. 3. Frequency of a power tiller utilization was high during the month of June, July and October while it was low during February and December . 4. Distribution of repairing cost was 8.5% for trailer, 7.1% for throttle lever and 6.7% for casket, respectively. The annual cost for repairing was 5,290 won.5. The annual cost for using a power tiller was composed of 51.5% of fixed cost and 48.5% of operating cost. 6. Economic analysis showed that it was not economically practical for individual ownership of a power tiller on the farm surveyed. Therefore, custom operation and joint ownership by a few farmers were recommended.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.24-30
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• 2014

This study investigates computing offloading effect of cloud in real-time video personal broadcast service, whose server is mobile device. Mobile device does not have enough computing resource for encoding video. The computing burden is offloaded to cloud, which has abundant resources in terms of computing, power, and storage compared to mobile device. By reducing computing burden, computation energy can be saved while transmission data amount increases because of decreasing compression efficiency. This study shows that the optimal operation point can be found adaptively to time-varying LTE communication condition result of tradeoff analysis between offloaded computation burden and increase in amount of transmitted data.

• Journal of Pharmacopuncture
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• v.17 no.3
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• pp.74-77
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• 2014

Objectives: The purpose of this study is to report a case of a plexiform neurofibroma (PNF) in the pelvic region treated with sweet bee venom (SBV) and mountain ginseng pharmacopuncture (MGP). Methods: A 16-year-old girl was diagnosed as having PNFs, neurofibromatosis type 1, 10 years ago and she had surgery three times to remove the benign tumors, but the growth of the PNFs continued. She has been treated in our clinic with SBV and MGP two times per month from March 2010 to April 2014. SBV was injected intra-subcutaneously at the borders of the PNFs in the pelvic region, and MGP was administrated intravenously each treatment time. Results: The growths of the PNFs occurred rapidly and continued steadily before treatment. Since March 2010, she has been treated in our clinic, and the growths of the PNFs have almost stopped; further-more, the discomfort of hip joint pain has been reduced, and her general condition has improved. Conclusion: We cautiously conclude that SBV and MGP treatment has some effects that suppress the growth and the spread of the PNFs in this patient.

• Journal of the Korea Institute of Building Construction
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• v.13 no.1
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• pp.38-47
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• 2013

When building with concrete in cold weather, an insulation method of heat curing must be determined, and a holistic curing plan that considers the characteristics of structures, the heat loss coefficient of a curing sheet, the joint condition of the curing materials and the quantity of heat produced by a heating apparatus is an essential prerequisite for protection against early frost damage. But on a number of national construction sites, there have been serious problems in cold weather concreting due to the unreliability of the information obtained from practical experience. In the construction field in Japan, there is a specification for heat curing prepared by Japanese Architectural Society, which provides an equation for calculating heat quantity. It is also necessary to adopt a detailed specification for a standard heat curing method that is applicable to all national construction sites. In this study, the effect of bubble sheets on the economic feasibility of cold weather concrete is investigated through a comparison with the blue sheets commonly prescribed in national construction sites. In conclusion, this study found that bubble sheets had the effect of reducing the cost of curing materials and the fuel cost consumed by a heating apparatus, compared to the use of blue sheets.