• The Journal of Korean Physical Therapy
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• 제15권2호
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• pp.52-66
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• 2003

The intervertebral disc is a cartilaginous structure that resembles articular cartilage in its biochemistry, but morphologically it is clearly different. It shows degenerative and ageing changes earlier than does any other connective tissue in the body, It is believed to be important clinically because there is an association of disc degeneration with back pain. Degenerative changes in the intervertebral disc are thought to develop as aging, mechanical stress and metabolic factors. Genetic factors may also play a part in the onset or progress of the degenerative process. They, together with environmental factors, may act as determinants of the structural characteristics of the intervertebral disc and produce a tendency to generation, In this short review we outline the morphplogy and biochemistry of normal intervertebral disc and the changes that arise during degeneration. Therefore this study will review degeneration of intervertebral disc, so we will have knowledge about low back pain associated with degenerative change in the intervertebral disc.

• 열처리공학회지
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• 제20권5호
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• pp.243-249
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• 2007

The age hardening behavior and mechanical properties of an extruded Al-Zn-Mg-(Cu)-0.1 wt.%Sc alloy were investigated with the Sc addition and ageing temperature. The results showed that the $Al_3Sc$ compounds were formed by Sc addition and distributed preferentially along the extrusion direction. The age hardening of Al-Zn-Mg-Cu-0.1 wt.%Sc alloy which was treated by T6 process was more significant than that of Al-Zn-Mg-0.1 wt.%Sc alloy. The tensile property of Al-Zn-Mg-Cu+0.1 wt.%Sc alloy was also higher than that of Al-Zn-Mg-0.1 wt.%Sc alloy, which is 691 MPa and 584 MPa in strength and 9% and 11% in elongation, respectively.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
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• pp.403-414
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• 2003

Periodic safety review on Kori Unit 1 has been successfully done for the first time in Korea. 11 safety factors of the review were fully evaluated in accordance with the domestic legal system. Although it is the oldest nuclear power plant in Korea, Kori Unit 1 was found to have maintained good operating conditions and continuously enhanced its safety by implementing post-TMI action plans and other safety issues, such as replacing steam generators and process/control system. It can be therefore confirmed that safe operation of Kori Unit 1 is guaranteed until next periodic safety review. Nevertheless, some corrective action items were recommended to enhance further its safety level, such as equipment qualification, additional ageing management program, strengthening of some procedures related to administration and human factor. The results of PSR can be utilized for the continued operation beyond the design life as long as the plant safety is maintained and improved. Experiences of the PSR on Kori Unit 1 can be also applied to PSR on other plants.

• Fibers and Polymers
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• 제7권2호
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• pp.105-111
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• 2006

Coating the fibre surface by in situ oxidative chemical polymerisation of polypyrrole (using $FeCl_3$ as oxidant) is a readily industrial applicable way to give electrical properties to wool with good ageing stability [1], although pre-treatments are required to avoid damage of the cuticle surface due to the acidic condition of the process. FT-IR and EDX analysis reveal that organic sulphonates and sulphates, used as dopants, are absorbed by wool, while chlorine ions are preferably embedded on the polypyrrole layer. The resulting electrical conductivity seems mainly due to the presence of chlorine as counter-ion of polypyrrole; nevertheless, the presence of arylsulphonate in the polymerisation bath increases the electrical conductivity of the coating layer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1569-1571
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• 2000

The ageing process was checked by leakage current monitoring in Salt Fog Method. In order to monitor leakage current, DAS with 12-bit, 8-channel A/D converter was prepared. The monitored components of leakage current were averages of the rms and peak, max peak, cumulative charge, and the cumulative number of peak pulses. The acquired data were stored to the disc periodically. And, surface conductivity was measured to investigate loss of hydrophobicity. The results suggest that surface conductivity and leakage current are well corresponding to initial loss of hydrophobicity.

• 보존과학연구
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• 통권28호
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• pp.149-168
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• 2007

This project aims to develop a partnership between France and Korea; the field of paper conservation with two mains objectives. The first object is to study the possibilities of implementing the use of traditional Korean paper in conservation workshops in France and Europe. The second one is to establish a long term collaborative research program to investigate the degradation mechanisms of ancient papers and particularly early waxed manuscripts founded in Korea and France which are now brittle and fallen into parts. This problem deserves an investigation using analytical tools such as SEC/MALS, GC/MS to understand the interactions between wax and cellulose during the ageing process and to recommend proper conservation treatment. A research plan could be establish for both institution in order to facilities an exchange of visiting scholars (scientist, post-doc) to implement and share knowledge and for carrying out the research.

• 대한건축학회논문집:구조계
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• 제34권12호
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• pp.51-56
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• 2018

Due to the aging of economically active population in the world, the average age of workers in the domestic construction industry is also steadily increasing. This study analyzes the aging of construction workers in small-size construction sites in Busan, where the aging of the economically active population is the most severe in Korea. As a result of the study on the aging of construction workers in six construction sites with a construction cost of less than 500 million won in Busan, it was found that 65% of the workers were over 50 years of age. In addition, several experts interviews and survey revealed that 'securing welfare facilities for construction workers' and 'diminishing prejudice about the construction industry" were the most urgent and effective methods to overcome the aging problems. The results of this study can be served as basic data to solve the aging problems in the industry.

• 한국자동차공학회논문집
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• 제13권3호
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• pp.80-86
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• 2005

In this study, we investigated the characteristics of the conversion efficiency and the effect of ageing Diesel Oxidation Catalyst (DOC). The DOC was composed of Warm-up Catalytic Converter (WCC) and Underbody Catalytic Converter (UCC). As the result, the conversion efficiency of THC was 10$\~$50$\%$ on WCC and 30$\~$40$\%$ on UCC .The conversion efficiency of CO was 80$\~$90$\%$ on WCC and remained 10$\~$20$\%$ of CO was purified on UCC. The WCC shows high conversion efficiency on CO. After 20 hours aging process of engine bench, conversion efficiencies of THC and CO were improved a little, because it was activated catalyst surface by 20 hours aging. In case of 80 hours aging, the conversion efficiencies of THC and CO were decreased on WCC. However, the UCC was not affected by aging process .

• 대한간호학회지
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• 제47권4호
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• pp.562-574
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• 2017

Purpose: This study attempts to explore the subjective experience of frailty among elderly individuals in Korea. Methods: From June to August in 2014, 11 elderly persons who had experienced frailty in a community were interviewed. For data analysis, the method suggested by Colaizzi was applied as a phenomenological method. Results: According to the analysis, the study participants' frailty process was structured in seven categories: (a) 'natural phenomenon with ageing,' (b) 'life force comes to an end,' (c) 'the light in my heart turns off,' (d) 'unavoidable situation,' (e) 'continuous and connected vicious cycle,' (f) 'the limit of recovery energy already passes,' and (g) 'life is supported by someone's help.' Conclusion: The frailty experience in the participants is a natural process of aging, which cause vicious cycle acting with each other among physical, psychological, and social health. It is said that the cycle of frailty was started from weight loss and insufficient sleep, and boostered by pain. The participants from repetition of the vicious cycle become exhausted and pass the threshold of their recovery energy at some points. If they meet with sudden accidents such as falling, traffic accident and so on, they become to live a dependent life supported by someone's help in a moment. To prevent frailty and worsening conditions in Korean elderly individuals, it is recommended to provide a interventional programs using this study's results.

• 열처리공학회지
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• 제18권3호
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• pp.172-176
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• 2005

Modern automobiles are built with a steadily increasing variety of materials and semifinished products. The traditional composition of steel sheet and cast iron is being replaced with other materials such as aluminum and magnesium. But low formability of these materials has prevented the application of the automotive components. The formability can be enhanced by conducting the warm hydroforming using induction heating device which can raise the temperature of the specimen very quickly. The specimen applied to the test is A6061, A7075 extruded tubes which belong to the age-hardenable aluminum alloys. But in the case of A6061 age hardening occurs at room temperature or at elevated temperatures before and after the forming process. In this study the effects of the heating condition such as heating time, preset temperature, holding time during die closing and forming time on the hydroformability are analyzed to evaluate the phenomena such as dynamic strain hardening and ageing hardening at high temperatures after the hydroforming process.