• Korean Journal of Health Education and Promotion
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• v.32 no.3
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• pp.97-107
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• 2015

Objectives: The current study aims to examine whether the influence of National Long-term Care Insurance(NLCI) on the quality of life(QoL) trajectory of older adults with disabilities is more positive than its influence on those without disabilities. Methods: Sample consisted of 5,362 elderly aged 65 and over who participated in the Korean Welfare Panel Study from Wave1 to Wave7. Data were analyzed using latent growth curve modeling. Results: Major findings are as follows. (1) Before the NLCI, the trajectories of QoL between older adults with disabilities and those without were same. (2) After the NLCI, elders with disabilities showed lower levels of QoL at the beginning, but the gaps gradually decreased with time. These results indicate that the implementation of NLCI more positively affected elders with disabilities than those without disabilities. Conclusions: These results suggest that the NLCI functions properly as one of social security nets to cope with the needs of older adults with disabilities. In conclusion, it is critical to develop a sustainable NLCI system to enhance the QoL of older adults with disabilities.

• The Korean Journal of Applied Statistics
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• v.25 no.6
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• pp.897-915
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• 2012

This paper examines the relationship between the stock and futures markets in terms of lead-lag relationship, correlation and the hedge ratio using wavelet analysis. The basic finding is that the relationship between the two markets significantly depends on the time-scale. First, there is a feedback relationship between the stock and futures markets in the long-run scale; however, weaker evidence is observed in shorter-run scales. Second, wavelet correlation between the two markets increases for a longer time scale. Third, the hedge ratio and the effectiveness of hedging strategies increase as the investment horizon gets longer. The results in this paper indicate that the stock and futures series are perfectly correlated in the long run and are tied together over long horizons.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.414-415
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• 2006

At present, Characteristic of high color reproduction for LCD products needed in Display market. Therefore, The improving methods of high color reproduction are alteration of color Filter or Red, Green, Blue phosphor alteration of CCFL. But High color reproduction phosphor is short life time as compared with conventional phosphor. In this experiment, by using split the Red, Green, Blue CCFL with high color reproduction phosphor instead of conventional high color reproduction CCFL. We knew that the high color reproduction RGB split CCFL BLU has same spectrum data and chromaticity, but has long life time as manufacturing RGB split CCFL and reduce chromaticity shift following long time discharge as compared with conventional high color reproduction CCFL.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.91-99
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• 2007

For the detection of Human Immunodeficiency Virus (HIV), multiple and ultra-rapid real-time PCR methods were developed. The target DNA sequences were deduced from HIV-1 specific 495bp partial env gene (gi_1184090) and from HIV-2 specific 294 bp partial env gene (gi_1332355), and were synthesized by using PCR-based gene synthesis on the reason of safety. Ultra-rapid real-time PCR was performed by $Genspector^{TM}$ using microchip-based, $1\;{\mu}l$ of reaction volume with extremely short time in each 3 step in PCR. The detection including DNA-amplification and melting temperature analysis was completed inner 15 minutes. The HIV-1 specific 117 bp-long and HIV-2 specific 119 bp-long PCR products were successfully amplified from minimum of template,2.3 molecules of each env gene. This kind of real-time PCR was designated as ultra-rapid real-time PCR in this study and it could be applied not only an alternative detection method against HIV, but also other pathogens using PCR-based detection.

• Journal of the Korean Society of Costume
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• v.56 no.3 s.102
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• pp.81-90
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• 2006

The objective of the study is to review trends of clothing export in important countries of the world and thus to know the present stage of clothing export in Korea. For the purpose, changes of export amount, competitiveness and product life cycle were analysed in the countries from the 1960's to the 1990's. The results are as following: First, on the aspect of export amount, industrialized countries lost the lead to newly industrializing countries from the 1960's. Developing countries, as China, win the lead. Second, on the competitiveness aspect, industrialized countries lost competitiveness to newly industrializing countries before the 1960's. And newly industrializing countries were outpaced by China in the export competitiveness from the early 1990's. Third, on the aspect of product life cycle, industrialized countries go first through each period of product life cycle, introduction, growth, maturity and decline, and they all, excluding Japan, sustained period of Maturity for a long time. newly industrializing countries and developing countries go orderly through each period of product life cycle after industrialized countries. As to Korea, duration of each period was short. Specially characteristics of decline period appeared partly in the early 1990's. From the results, the theory of product life cycle, helping to explain changes in production and trade in new product lines, estimated to applicable to clothing export. The phenomena, Italy, Hong Kong and America sustain high competitiveness in the world clothing market for a long time, is needed to be studied carefully. The study about strong points in their clothing industries and competitiveness drive program be to influence Korean export policy in the future.

• Journal of Applied Reliability
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• v.15 no.4
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• pp.270-275
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• 2015

Purpose : UHMWPE (Ultra-high-molecular-weight-polyethylene) is one of the most widely used material in knife protection clothes because of high strength, elasticity, and light weight. The purpose of this study is to develop the accelerated life test method and predict the lifetime for the knife protection fabric composed by UHMWPE. Methods : In this study, degradation characteristics of UHMWPE fibers and knife protection fabric for cut resistance were evaluated under the hydrolysis and photo-degradation conditions. It was found out that the degradation rate of retained tensile strength was more significant in the photo-degradation than hydrolysis. Therefore, the failure time was determined as the time that the retained tensile strength in photo-degradation is less than 50%. Considering an acceleration factor for irradiance and exposure time, the lifetime was predicted from the calculated failure time. Results : As a result of the accelerated life test, the $B_{10}$ lifetime of knife protection fabric composed by UHMWPE fibers is estimated as 2.8 years for a 90% statistical confidence level. Conclusion: Since the lifetime is predicted by the view-point of radiant exposure in this study, there is a possibility that the estimated lifetime may differ from the actual lifetime. However, it is considered as an useful methodology to estimate the long-term lifetime of knife protection fabrics.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.237-242
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• 2014

Recently much research are has been done into the compositions of lead-free solders. As a result, there has been a rapid increase in the number of new compositions. In the past, the properties of these new compositions were determined and verified through drop-impact tests. However, these drop tests were expensive and it took a long time to obtain a result. The main goal of this study was to establish an analytical method capable of predicting the impact life-time of a new solder composition for board-level flip chips though the application of drop simulations using LS-DYNA. Based on the reaction load obtain with LS-DYNA, the drop-impact fracture cycles were predicted. The study was performed using a Sn-3.0Ag-0.5Cu solder (305 composition). To verify the reliability of the proposed analytical method, the results of the drop-impact tests and life-time analysis were compared, and were found to be in good agreement. Thus, the new analytical method was shown to be very useful and effective.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.163-168
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• 2002

Hot forging is widely used in the manufacturing of industry machine component. The mechanical, thermal load and thermal softening which are happened by the high temperature in hot forging process. Tool life decreases considerably due to the softening of the surface layer of a tool caused by a high thermal load and long contact time between the tool and billet. Also, tool life is to a large extent limited by wear, heat crack and plastic deformation in hot forging process. These are one of the main factors affecting die accuracy and tool life. That is because hot forging process has many factors influencing tool life, and there was not accurate in-process data. In this research, life prediction of hot forging tool by wear and plastic deformation analysis considering tempering parameter has been carried out for automobile component. The new developed technique in this study for predicting tool life can give more feasible means to improve the tool life in hot forging process.

• Journal of Applied Reliability
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• v.7 no.1
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• pp.31-43
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• 2007

The function of O-ring seals is to prevent leakage during the service life of the components in which they are installed. The life prediction of O-ring is very important at various industry fields. Generally, to evaluated the long-term performance of O-ring in severe environments has applied a life prediction technique based on accelerated life test (ALT). In this work, Accelerated thermal aging test(l20, 130, 140, $150^{\circ}C$) of O-ring was applied for life prediction of O-ring. The property changes after thermal aging test was measured using TGA, DSC, FT - IR, Video Microscope and SEM. Shape parameter and life prediction were obtained using MINITAB program.

• Tribology and Lubricants
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• v.25 no.3
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• pp.171-175
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• 2009

One of the critical issues associated with the 40mm long hollow cylinder's development and maintenance is the prediction of cylinder erosion. The actual firing test is the most accurate method to measure the cylinder erosion rate. But it costs a great deal and requires a long measurement time. Hence many empirical methods have been proposed to predict the erosion rate and life span of long hollow cylinders. An EFC formula is calculated. An approximate erosion formula for the ammunition type A is derived to interpolate 16 observation values up to 4,000 rounds. A new erosion equation and muzzle velocity formula are also suggested. Several numerical results are presented.