• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.691-698
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• 2010

In this study Al-doped ZnO (AZO) thin films have been fabricated on Eagle 2000 glass substrates at various substrate temperature ($100{\sim}500^{\circ}C$) and working pressure (10 ~ 40 mTorr) by RF magnetron sputtering in order to investigate the structural, electrical, and optical properties of the AZO thin films. The obtained films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The AZO thin films, which were deposited at $T=300^{\circ}C$ for 10 mTorr, shows the highest (002) orientation, and the full width at half maximum (FWHM) of the (002) diffraction peak is $0.42^{\circ}$. The lowest resistivity ($2.64{\times}10^{-3}\;{\Omega}cm$) with the highest cartier concentration ($5.29{\times}10^{20}\;cm^{-3}$) and a Hall mobility of ($6.23\;cm^2/Vs$) are obtained in the AZO thin films deposited at $T=300^{\circ}C$ for 10 mTorr. The optical transmittance in the visible region is approximately 80%, regardless of process conditions. The optical band-gap depends on the Al doping level as the substrate temperature increases and the working pressure decrease. The optical band-gap widening is proportional to cartier concentration due to the Burstein-Moss effect.

• Fire Science and Engineering
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• v.34 no.2
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• pp.147-155
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• 2020

This paper presents a study on the development of a fire extinguishing agent and extinguishing system for an energy storage system (ESS) fire. The fire extinguishing agent designed to extinguish an ESS fire is a highly permeable fire extinguisher that reduces the surface tension and viscosity while bringing about cooling action. This is the main extinguishing effect of this type of wetting agent, which displays the characteristics of fire extinguishing agents used for penetrating the battery cells inside the ESS module. For the fire extinguishing system, a local application system was designed to suppress fire on a rack-by-rack basis. A 360° rotating nozzle was inserted into the rear hall of the ESS module, and general nozzles were installed in the rack to maximize the fire extinguishing effect. The fire extinguishing agent was strongly discharged by virtue of the gas release pressure. Experiments on fire suppression performance with ESS module 1 unit and module 3 units showed that all visible flames were extinguished in 8 s and 9 s, respectively, by the fire extinguishing agent. In addition, based on confirming reignition for 600 s after the fire extinguishing agent was exhausted, it was confirmed that the ESS fire was completely extinguished without reignition in all fire suppression performance experiments.

• Korean Journal of Social Welfare
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• v.55
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• pp.205-230
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• 2003

This article examines the continuity and change of Korean welfare regime during 1990s. Democracy, globalization and the financial crisis changed the landscape of Korean society as a whole and provided a catalyst for the change of the Korean welfare regime. In order to show how and what changed in Korean welfare regime, this study concentrates on the transformations of income maintenance programmes and social welfare services. The changed aspects are as follow: (1) The ratio of social expenditure to GDP has increased during 1990s and now stood at ten percent level. (2)Rather than backing up the company welfare, government strove to build and expand income maintenance devices for all citizens. (3) The poverty and inequality reduction effects of income maintenance programs are very weak in early 1990s, but they are gradually getting stronger impact on poverty and inequality. But, there are also continuance. (1) In spite of the relative development of income maintenance programs, social welfare services are still poorly designed as before. (2) The expenditure level of social welfare services shows sharp contrast to income maintenance programs and lagged behind the other OECD countries. (3) The expansion of social service sector employment are also not so salient. In 2002, social service employment is only at close to 2.5 per cent of the total employment. Accordingly, korean welfare regime is now characterized by a model which is to curb poverty and inequality by engaging in direct government provision of income maintenance programs, but refrain from expanding social service by relying on net welfare which encourage the provision of services within the family. A implication of our analysis is that the expansion of social welfare Korea saw after 1997 was not really an regime shift. According to the arguments of Peter Hall, first and second order changes in policy do not automatically lead to third order changes which imply regime shift. Policy changes which occurred during 1990s was not accompanied by a shift in policy paradigms. Family dependency in welfare is not yet changed.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.731-737
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• 2000

Objective : Growth factor receptors on the tumor cells are known to be expressed highly allowing the tumor cells to bind growth factors to stimulate cellular division. Immunotoxin therapy is one of the novel approaches to the primary malignant brain tumor, and expression of cell-surface receptor is essential for the immunotoxin to have specific anti-tumor activity. Despite promising cytotoxic activity of immunotoxin, tumor responses are not curative on clinical trials, and additional studies are needed regarding various factors influencing the efficacy of the immunotoxin. The purpose of this study is to detect the expression of various growth factor receptors on brain tumor cell lines which are going to be used in these studies. Materials and Methods : The authors detected transferrin receptor(TR), insulin-like growth factor-1 receptor(IGF-1R), and interleukin-4 receptor(IL-4R) on medulloblastoma cell line(Daoy) and glioblastoma cell lines(U373 MG and T98 G) by flow cytometric analysis. Results : TR was expressed on Daoy, U373 MG, and T98 G. IGF-1R was expressed on Daoy and U373 MG, but not on T98 G. IL-4R was expressed on all cell lines tested. Conclusion : The transferrin and interleukin-4 receptors might be good targets for immunotoxin therapy. The results should be considered in additional in vitro and in vivo studies regarding immunotoxin and in establishing the proper treatment model of the immunotoxin therapy including selection of the adequate immunotoxin.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.273-279
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• 2005

The degradation of o-chlorophenol(o-CP) in the presence of NaOH and the byproducts formed were investigated in a supercritical water(SCW) destruction process. The conversion of o-CP in the absence of NaOH was less than 20%, however it showed 100% conversion in the presence of NaOH(mole ratio[NaOH]/[o-CP] over than 2) with a residence time of less than 1 second. The formation of PAHs and the phenolic compounds formed were decreased in the presence of NaOH. The results revealed that the formation of byproducts during the destruction of o-CP in SCW was effected by the addition of NaOH. Phenol, cresols, chlorinated phenols, PAHs, p,p'-dihydroxybiphenyl and oxygenated polyaromatic compounds such as 1-indanone, dibenzofuran and dibenzo-p-dioxin were detected in both conditions(presence and absence of NaOH). At the same time, in the presence of NaOH, 2-ethylphenol, o-hydroxyacetophenone, hydroquinone, 4-allylphenol, 3-phenoxyphenol and 4,4'-oxybisphenol were also detected. The observed results suggest that the destruction of o-CP in SCW with NaOH occurs through a number of complicated reaction pathways. Dibenzofuran and dibenzo-p-dioxin were also detected during destruction of o-CP by SCW. The above observation suggests that there may be a common relationship between the thermal incineration process and SCW decomposition process.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.84-84
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• 1999

최근 큰 잔류분극을 가진 강유전체 Pb(Zr, Ti)O3 박막을 이용한 비휘발성 기억소자의 연구가 활발히 진행되고 있다. 그러나 Pb(Zr, Ti)O3 박막을 비휘발성 기억소자로 응용하는 경우 분극피로(polarization fatigue), imprint, 누설전류 등의 문제점이 나타나는 것으로 알려져 있다. 특히 분극반전 횟수가 증가할수록 잔류분극이 감소하는 분극피로 현상은 비휘발성 기억소자의 응용에 있어서 치명적인 장애가 되므로 기억소자의 실용화를 위해서는 분극피로 현상의 개선이 무엇보다 중요하다. 본 연구에서는 Pb(Zr, Ti)O3 강유전체 박막의 분극피로 현상을 규명하고 개선하기 위해서 다음과 같은 세가 실험적 방법으로 접근하였다. 먼저 Pt와 금속산화물인 LaNiO3을 이용하여 상·하부 전극을 달리하여 제조한 축전기에 대해서 분극피로 특성을 관찰하고 이로부터 분극피로 현상에 대한 전극의 효과를 조사하였다. 여기서 금속산화물인 LaNiO3 박막과 Pt 박막은 r.f. 스퍼트 법으로 증가하였으며 Pb(Zr, Ti)O3 박막은 LaNiO3/Si(100)/와 Pt/Ti/SiO2/i(100) 기판위에 졸겔법으로 제조하였다. 다음으로 분극피로된 박막의 상부전극에 극성이 다른 직류전압을 인가해주었을 때 나타나는 분극회복 현상을 광범위하게 관찰하였으며, 특히 직류전압의 극성에 따라 비대칭적인 분극회복 특성을 보였다. 마지막으로 이와 같은 직류전압에 대한 비대칭적인 분극회복현상에 착안하여 양과 음의 방향으로 바이어스된 스윗칭 펄스를 인가하여 분극피로 특성을 조사한 결과 비대칭적인 분극피로 현상을 관찰할 수 있었다. 이와 같은 Pv(Zr, Ti)O3 박막의 분극피로와 회복의 비대칭적인 현상은 분극피로 현상의 기구를 밝히는 중요한 근거가 되었으며, 본 연구에서는 하부 계면에서의 산소빈자리의 역할로 분극피로 현상을 모형화하였다.식각하기 시작하였으며, 19.5J/cm2에서 유리기판의 rudraus(격벽 두께 130$\mu\textrm{m}$)까지 식각하였다. 대한 정보(RDF)는 명확하게 얻을 수 있었다.nospec과 SEM으로 관찰하였다. 또한 Ge 함량 변화에 따른 morphology 관찰과 변화 관찰을 위하여 AFM, SEM, XRD를 이용하였으며, 이온주입후 열처리 온도에 따른 활성화 정도의 관찰을 위하여 4-point probe와 Hall measurement를 이용하였다. 증착된 다결정 SiGe의 두게를 nanospec과 SEM으로 분석한 결과 Gem이 함량이 적을 때는 높은 온도에서의 증착이 더 빠른 증착속도를 나타내었지만, Ge의 함량이 30% 되었을 때는 온도에 관계없이 일정한 것으로 나타났다. XRD 분석을 한 결과 Peak의 위치가 순수한 Si과 순수한 Ge 사이에 존재하는 것으로 나타났으며, ge 함량이 많아짐에 따라 순수한 Ge쪽으로 옮겨가는 경향을 보였다. SEM, ASFM으로 증착한 다결정 SiGe의 morphology 관찰결과 Ge 함량이 높은 박막의 입계가 다결정 Si의 입계에 비해 훨씬 큰 것으로 나타났으며 근 값도 증가하는 것으로 나타났다. 포유동물 세포에 유전자 발현벡터로써 사용할 수 있음으로 post-genomics시대에 다양한 종류의 단백질 기능연구에 맡은 도움이 되리라 기대한다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품 개발에 따른 새로운 수요 창출과 수익률 향상, 기존의 기능성 안료를 나노(nano)화하여 나노 입자를 제조, 기존의 기능성 안료에 대한 비용 절감 효과등을 유도 할 수 있다. 역시 기술적인 측면에서도 특수소재 개발에 있어 최적의 나노 입자 제어기술 개발 및 나노입자를 기능성 소재로 사용하여 새로운 제품의 제조와 고압 기상 분사기술의 최적화에

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.224-229
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• 2010

Indium oxide $(In_2O_3)$ thin films have been prepared on glass substrate by using radio-frequency reactive magnetron sputtering with changing the oxygen flow ratio. The substrate temperature was kept at a fixed value of $400^{\circ}C$, and the sputtering gas and reactive gas were supplied with argon and oxygen, respectively. The oxygen partial flow ratio was varied by controlling the amount of oxygen with respect to the total mixed gases, 10%, 20%, 30%, 40%, and 50%. The optical, electrical, and structural properties of the deposited thin films were investigated by using ultraviolet-visible-near infrared spectrophotometer, Hall measurement, and X-ray diffractometer and scanning electron microscopy. The $In_2O_3$ thin film deposited at 20% of oxygen flow ratio showed an average transmittance of 86% in the wavelength range of 430~1,100 nm, an electrical resistivity of $1.1{\times}10^{-1}{\Omega}cm$. The results show that the transparent conducting films with optimum conditions can be achieved by controlling the oxygen flow ratio.

• Fire Science and Engineering
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• v.25 no.2
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• pp.101-106
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• 2011

In case of an emergency such as a fire on a building and there is a need to evacuate the occupant in that building, it is important to have the guidance information effectively delivered to the evacuating occupants to guide them toward a safe direction using audio sensual media. And, it is also very important to prevent the evacuating occupants getting lost or falling astray, away from the direction toward safety. The purpose of this study, in this respect, is to examine the possible application of the precedent sound effect, with which the evacuating occupants may get a sense of the direction where the announcement comes from. With such an effect, an experiment was conducted to measure the extent to which people can hear the preceding and the following sound in terms of the acoustic pressure level changes and delay time changes, with a view to make the optimal evacuation-guidance announcement or sound. The optimal evacuation guidance sound (announcement) per each of the experimental indoors environments were as follows; 1) Regarding the optimal condition for the evacuation guidance announcement sound in the space of a lecture room, the direction of the advanced sound is positively recognized when the follow-up sound has the delaying time of 10 ms~50 ms in comparison with the advanced sound or when there is no difference between the acoustic pressures of the advanced and follow-up sounds or the acoustic pressure of the advanced sound is higher than that of the follow-up sound. 2) Regarding the optimal evacuation guidance announcement sound in the space of a hall, the advanced sound is positively recognized when the follow-up sound has the delaying time of 20 ms~60 ms in comparison with the advanced sound. 3) Regarding the optimal evacuation guidance announcement sound in the space of a gymnasium, the advanced sound is positively recognized when the follow-up sound has the delaying time of 10 ms~40 ms in comparison with the advanced sound or when the sound pressure of the advanced sound has a higher level than or the same level as that of the follow-up sound.

• Journal of Cadastre & Land InformatiX
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• v.50 no.2
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• pp.53-68
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• 2020

The Cadastral Renovation is a National project to investigate and survey the registration of Cadastral Record and replace the existing Cadastral Record with a new Cadastral Record by digital, and to correct the registration of Cadastral Record if the registration of Cadastral Record does not match the actual status of the land. The Business Period generally takes about one year and six months to two years. The time required is getting longer due to problems that occur in the course of the Adjustment amount after the cadastral resurvey survey due to complex structure and internal conflict due to the interest between landowners. After Boundary Decision of the real boundary, the land area is confirmed by the landowners, and the cadastral office is to settle the Cadastral Renovation by calculating the Adjustment amount according to the confirmed area and the increase and decrease of the cadastral area. Therefore, the solution plan was suggested so that reasonable Adjustment amount can be applied through empirical research applied to the time of calculation of Adjustment amount and the method of calculation of Adjustment amount. The improvement method showed the expected effect that can lead the agreement with the landowner to the shortest period, and it was also possible to set the real boundary that meets the purpose of the Cadastral Renovation. This study suggests improvements in the method of calculating standard Adjustment amount, the method of imposing Adjustment amount, and the method of boundary adjustment that does not impose adjustment amount through the cadastral Renovation and parallel studies, and it is expected that the Cadastral Renovation will be completed by 2030.

• 한국노년학
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• v.39 no.2
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• pp.241-259
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• 2019

The purpose of this study was to study the performance of volunteer work for the elderly from the perspective of self-efficacy and self-extension of the elderly, not from successful aging or productive aging. Through this, the research aims to confirm the expansion of internal growth and self-sufficiency that can occur in old age, and to provide an opportunity to re-examine one's life in old age. In order to verify the purpose of this research, questionnaires were distributed to 300 senior citizens who participated in volunteer activities at the City Hall and the District Office of Busan Metropolitan City over a period of three months from September to November 2018 and used the data from 266 questionnaires for the study, excluding the 34questionnaire answered unfaithfully. The results of the study are as follows. First, the motivation for volunteering activities (value function, social function, understanding function) of the elderly has a positive effect on self-efficacy. Second, the motivation for volunteering activities (value functions, social functions, understanding functions) have a positive effect on self-extension. Third, it has been shown that the elderly's sense of self-efficacy (self-regulation efficacy, confidence) has a positive effect on their self-extension. Fourth, it was found that self-efficacy has a mediated effect on the motivation of the elderly to participate in volunteer activities and the relationship of self-extension. This study identified the relevance of the motivation for volunteering activities of the elderly to influence their effectiveness and self-extension. In particular, the research suggests practical and policy measures for the revitalization of volunteer activities of the elderly by providing a new perspective on the welfare of the elderly by utilizing parameters of self-efficacy, a psychological and social concept for the elderly.