• Earthquakes and Structures
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• v.14 no.5
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• pp.437-447
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• 2018

Computational cost is one of the major obstacles for detailed risk analysis of structures. This paper puts forward a methodology for efficient probabilistic seismic loss assessment of structures using the Endurance Time (ET) analysis and the first-order reliability method (FORM). The ET analysis efficiently yields the structural responses for a continuous range of intensities through a single response-history analysis. Taking advantage of this property of ET, FORM is employed to estimate the annual rate of exceedance for the loss components. The proposed approach is an amalgamation of two analysis approaches, ET and FORM, that significantly lower the computational costs. This makes it possible to evaluate the seismic risk of complex systems. The probability distribution of losses due to the structural and non-structural damage as well as injuries and fatalities of a prototype structure are estimated using the proposed methodology. This methodology is an alternative to the prevalent risk analysis framework of the total probability theorem. Hence, the risk estimates of the proposed approach are compared with those from the total probability theorem as a benchmark. The results indicate a satisfactory agreement between the two methods while a significantly lower computational demand for the proposed approach.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.11-18
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• 2008

Purpose: The purpose of this study was to identify the effect of the physical activity promotion program on physical function and quality of life in the elderly. Method: The research was designed with one single pre-post group. The study group of 295 elderlies were selected through the convenience sampling form in a senior citizen's center in Ulsan city. The subjects received the physical activity promotion program for 60 min three times a week for 3 months. To evaluation the effects of the physical activity promotion program, body mass index (BMI), physiological index, physical function (muscle endurance, agility, balance) and quality of life were measured at before and after the program. The data was analyzed through SPSS 10.0 program for descriptive statistics and paired t-test. Result: After performing the physical action promotion program for 3 months, the results were follows. 1) There were significantly increased in BMI (t=4.36, p=.000). 2) There were significantly decreased in diastolic pressure (t=.68, p=.009). 3) There were significantly improved in muscle endurance (t=6.50, p=.000), agility (t=4.74, p=.000) and Rt. leg balance (t=4.15, p=.000). 4) There were significantly improved in quality of life (t=7.28, p=.000). Conclusion: These findings showed that the physical activity promotion program was effective in improving physical function and quality of life in the elderly. Therefore, the physical activity promotion program could be applied as an effective nursing intervention program for the elderly to promote their health.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.47-54
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• 2014

Endurance of ship hull can be estimated by existing regulations and fatigue estimation methods. These can be applied to the hull materials that are recommended by ship regulations but can't be applied to new materials. In this study, structural force in the worst sailing condition is obtained by the acceleration measurement test of small polyethylene boat and the endurance of small polyethylene hull is estimated by rainflow cycle counting method and linear cumulative damage rule. Maximum Von-Mises stress on the polyethylene boat is 1.8MPa and much lower than the fatigue strength of at least 5.9MPa for the fatigue life of $1{\times}10^9$ cycles. Fatigue life of the polyethylene boat hull is estimated to be 6,229 years.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1165-1171
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• 2005

After 1974 an EMU, which is the first line opened, the car's term of endurance is introduced, End of life on the step, gradually the rate of cars out of service are increasing. In the country, we consider about recycled source, aspects of social economic of cars out of service and so on, treat efficiently and reasonable. According to research first we make investigations about the present situation and the actual condition of cars out of service then we should lay out schemes efficiently.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.28.1-28.1
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• 2008

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.67-72
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• 2012

In this study, the leak-free performance and sealing endurance safety of CNG fueling nipple in which are related to the contact normal stress and equivalent true stress have been analyzed for CNG automobile using a finite element analysis. For the conventional circular o-rings and new double-lip o-rings with an initial compression rate of 15 percentages, the leak-free performance of double-lip o-rings with two contact sealing spots is 41% higher than that of the conventional circular o-rings with a contact sealing spot. The FEM computed results present that the leak-free endurance safety of double-lip o-rings with two contact sealing spots is 5% higher than that of the conventional circular o-rings for initial compression ratio of 15 percentages and a gas compression pressure of 8MPa. And, the maximum equivalent true stress of double-lip o-rings is 10.2% higher than that of the conventional circular o-rings for the leak-free endurance safety. This means that the double-lip o-ring may guarantee the extended sealing life compared to that of a conventional circular o-ring.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.73-80
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• 2013

This study presents sealing behavior and endurance safety of V-grooved o-rings as functions of a strain, compression stress, and contact normal stress using a FEM technique. The FEM results on the sealing behavior and endurance safety show that the maximum strain, maximum compression stress, and maximum contact normal stress of V-grooved o-rings are approximately 1.2 times higher than those of conventional solid o-rings. This is why that an o-ring has a V-groove in the center between two overlapped circles, which is very effective in sealing for ball valves, pressure vessels, and gas equipment. And the extrusion failure in V-grooved o-rings does not take place under an increased gas pressure due to a V-groove. This may extend sealing life compared with that of a conventional solid o-ring.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.1-5
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• 2013

Printing papers published in between 1950's and 1990's were treated with three methods such as distilled water washing, $CaCO_3$ solution washing and methyl cellulose solution coating for improving their conservational properties. Accelerated aging with $80^{\circ}C$ and 80% RH for 14 days was applied to the testing papers. Results showed that distilled water and $CaCO_3$ washing kept increased pH even after accelerated aging, but did not improve folding endurances for 1950's-60's papers. Methyl cellulose treatment did not increased pH of the old papers, but increased folding endurances remarkably for 1950's-60's papers even after accelerated aging. It suggests that methyl cellulose treatment after $CaCO_3$ washing should give improvements both in pH and folding endurance.

• Journal of Life Science
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• v.11 no.2
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• pp.87-91
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• 2001

We conducted this study to analyze the effectiveness of a treatment called 12-week therapeutic recreation dance movement (TRDM) to elderly people in terms of health care and recovery. Forty two elderly people were participated in this study and divided into two groups with healthy (twelve) and unhealthy (thirty). After TRDM treatment, the muscular power was increased in both groups without statistical significance within and between groups. The flexibility, agility and balance were slightly increased in both groups. Although the elevation of muscular endurance was not significant between groups, it was statistically meaningful within groups. The results of body composition comparison did not reveal meaningful difference within and between groups. However, the amount of fat in serum and fat distribution percentages ware decreased in both groups. Both group appeared to be increased muscle mass. The level of body water was decreased in healthy group and increased in unhealthy group. Unhealthy group appeared to be decreased level of T-C, TG and LDL-C. In contrast, the unhealthy group revealed the increased level of HDL-C. These results demonstrate the effect of TRDM to elderly people. This effectiveness can be adapted for the protection and treatment of geriatics-related adult diseases such as diabetes, hypertension and hyperlipidemia.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.239-245
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• 2005

Through the fatigue test of plastic gears using polyacetal polymer, this research aims at providing basic data for not only specifying operation conditions of plastic gears, but also designing dimensions of plastic gears with giving fatigue life and the estimated equation of fatigue life of plastic gears. That is, from the fatigue life curves, the estimated equation of fatigue life of plastic gears is taken out. For the estimated equation of fatigue life of plastic gears, this research provides two test methods; one is preserving non-limited temperature of tooth flank, the other is preserving limited temperature of tooth flank. As results, how the temperature of tooth flank affects the fatigue life is shown. In addition, based on the endurance limit, the essential factors of the unit load and K-factor are determined, which are needed in the design of gear by bending strength and surface durability.