• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.372-375
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• 1988

The III-V ternary alloy semiconductor $In_{l-x}Ga_{x}As$ were grown by the temperature Gradient of $0.60{\leq}x{\leq}0.98$. The electrical properties were investigated by the Hall effect measurement with the Van der Pauw method in the temperature range of $90{\sim}300K$. $In_{l-x}Ga_{x}As$ were revealed n-type and the carrier concentration at 300K were in the range of $9.69{\times}10^{16}cm^{-3}{\sim}7.49{\times}10^{17}cm^{-3}$. The resistivity was increased and the carrier mobility was decreased with increasing the composition ratio. The optical energy gap determined by optical transmission were $20{\sim}30meV$ lower than theoretical valves on the basis of absorption in the conduction band tail and it was decreased with increasing the temperature by the Varshni rule. In the photoluminescence of undoped $In_{l-x}Ga_{x}As$ at 20K, the main emission was revealed by the radiative recombination of shallow donor(Si) to acceptor(Zn) and the peak energy was increased with increasing the composition, X. The diffusion depth of Zn increases proportionally with the square root of diffusion time, and the activation energy for the Zn diffusion into $In_{0.10}Ga_{0.90}As$ was 2.174eV and temperatures dependence of diffusion coefficient was D = 87.29 exp(-2.174/$K_{B}T$). The Zn diffusion p-n $In_{x}Ga_{x}As$ diode revealed the good rectfying characteristics and the diode factor $\beta{\approx}2$. The electroluminescence spectrum for the Zn-diffusion p-n $In_{0.10}Ga_{0.90}As$ diode was due to radiative recombation between the selectron trap level(${\sim}140meV$) and Zn acceptor level(${\sim}30meV$). The peak energy and FWHM of electroluminescence spectrum at 77K were 1.262eV and 81.0meV, respectively.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.3
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• pp.1-13
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• 2011

Objectives: This study was designed to investigate the analysis of apoptosis by Scirpi Tuber in Hela cell and MCF-7 cell. Methods: For cytotoxic effect of Scirpi Tuber extract, Scirpi Tuber extract were cultured on NIH3T3 cell in vitro. After treatment with various concentration of Scirpi Tuber, cell growth was evaluated in Hela cell and MCF-7 cell. Hoechst 33342 staining was performed to estimate DNA fragment effect of Scirpi Tuber on the apoptosis in Hela cell and MCF-7 cell. Annexin V/PI apoptosis assay was used to estimate the effects of Scirpi Tuber on the early apoptosis in Hela cell MCF-7 cell. All the stained cells were analyzed by a FACS. RT-PCR was used to estimate the apoptosis gene expression effect of Scirpi Tuber extract on Hela cell and MCF-7 cell. Results: Cytotoxic effect of Scirpi Tuber extract was not found on per NIH3T3 cell. The viability of Hela cell was significantly decreased Scirpi Tuber (500, $1000{\mu}g/m\ell$) in Hela cell 1day, 3day and 5days after treatment (p<0.01). The viability of MCF-7 cell was significantly decresed Scirpi Tuber ($1000{\mu}g/m\ell$) in MCF-7 cell (p<0.01), Scirpi Tuber ($500{\mu}g/m\ell$) in MCF-7 cell only 3days after treatment (p<0.01). In RT-PCR analysis, after treatment of $100{\mu}g/m\ell$ of ACR extract, BCL-2 were decreased and BAX, caspase-3 were increased both in Hela cell and MCF-7 cell. DNA fragmentation was observed the Scirpi Tuber on Hela cell and MCF-7 cell. As time goes on DNA fragmentation incresed. In Annexin V/PI apoptosis assay, after treatment of $1mg/m\ell$ of Scirpi Tuber, the early apoptotic cell increased both in Hela cell and MCF-7 cell. As time goes on apoptotic cell increased. Conclusion: Scirpi Tuber appears to have considerable activity on the apoptosis in Hela cell and MCF-7 cell.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.369-382
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• 2013

This study is to identify health promoting behaviors and health problems of female marriage immigrant in Korea and is an descriptive study for searching the factors influencing health problems of them. And to provide basic data for developing health promoting interventions for them. Methods: The tools for this study were HPLP II developed by Walker et al. (1995) and modified and translated by Park (2005), CMI developed by Weider et al. (1945) and translated by Go & Park(1980), and modified by Seo and Park(2010). Data were analyzed with descriptive statistics, t-test, ANOVA, and correlation and stepwise multiple regression with the SPSS WIN 18.0 program. Results Conclusion: Female marriage immigrants have done low level of health promoting behavior(2.01) and they had more mental health problems than physical health problems. Factors influencing health problems of the participants were found to be self-rated health and general character which includes age-gap with partner, partner's education and age of female marriage immigrant. Factors influencing self-rated health of the participants were found to be exercise of health promoting behaviors and monthly income. In consideration of this result, we need to provide health education and develop health programs for female marriage immigrant in Korea.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.646-654
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• 2014

The purpose of this study was to draw policy implications for the development and expansion of Korea's forest ODA through investigating the perceptions of stakeholder on the fields that contributed the development of forestry in Korea and would have competitiveness in developing countries and priority fields for Korea's forest ODA. For this, the survey was conducted for 248 subjects from the general and expert stakeholder groups. Chi-square test in cross analysis, independent sample t-test, ANOVA and Duncan test were conducted to compare the difference of perceptions by group. The whole general and expert groups consider that 'forest conservation and rehabilitation' contributed to the development of Korea's forestry most and consider its global competitiveness most high. Comparing expert groups, ODA experts evaluated the competitiveness of 'capacity building for policies, institutions and research' higher than the forestry experts. For priority fields of Korea's forest ODA, general groups perceived 'management of CERs' and 'conservation of biodiversity' most important, showing the clear difference in perception compared to that of experts. In Conclusion, for the effective forest ODA of Korea, the effort to fill the gap between the general and expert groups needs to be made, as well as developing forestry capacity building programs to cope with the fields such as climate change adaptation and biodiversity conservation, which is newly required in a global society, in addition to using the past experience of forest rehabilitation in Korea. It will be useful for the rehabilitation of North Korea's forest in the future.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.537-543
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• 2013

In this study, the push-pull structure polymer for organic photo voHaics (OPVs) was synthesized and characterized. The poly{4,8-didodecyloxybenzo[1,2-b;3,4-b]dithiophene-alt-5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]-thiadiazole} (PDBDT-TBTD) was synthesized by Stille coupling reaction using the benzothiadiazole (BTD) derivative as an electron acceptor and benzodithiophene (BDT) derivative as an electron donor. The structure of monomers and polymers was identified by $^1H-NMR$ and GC-MS. The optical, physical and electrochemical properties of the conjugated polymer were identified by GPC, TGA, UV-Vis and cyclic voltammetry. The number average molecular weight ($M_n$) and initial decomposition temperature (5% weight loss temperature, $T_d$) of PDBDT-TBTD were 6200 and $323^{\circ}C$, respectively. The absorption maxima on the film was about 599 nm and the optical band gap was about 1.70 eV. The structure of device was ITO/PEDOT : PSS/PDBDT-TBTD : $PC_{71}BM/BaF_2/Ba/Al$. PDBDT-TBTD and $PC_{71}BM$ were blended with the weight ratio of 1:2 which were then used as an optical active layer. The power conversion efficiency (PCE) of fabricated device was measured by solar simulator and the best PCE was 2.1%.

• Journal of dental hygiene science
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• v.8 no.1
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• pp.29-34
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• 2008

The purpose of this study was to make a comparative analysis of the oral health knowledge, attitude and awareness of students in schools equipped with and without a dental clinic in the city of Gwacheon. The subjects in this study were 782 students in that area. Out of them, 398 students attended a school furnished with a dental clinic, and 384 attended another school that wasn't equipped with a dental clinic. It's ultimately meant in this study to contribute to boosting the managerial efficiency of a school dental clinic and stepping up the development of quality oral health programs. The findings of the study were as follows: 1. When the students from the two schools were compared in terms of oral health knowledge, there wasn't any significant gap between the two groups in general. One difference was that the students from the school furnished with a dental clinic were more aware of presentive treatment provided by a dental clinic than the others from the other school. 2. As for attitude to oral health, there was no significant difference between the two in every regard except daily mean frequency of having a snack. 3. Regarding oral health belief, the students from the school equipped with a dental clinic had a better oral health belief in every aspect including health status, importance of oral health and interest than the others, and the difference between the two was significant. 4. Concerning perception of school dental clinic, the students from the school furnished with a dental clinic were better cognizant of it. As to the necessity of it, both groups viewed it as necessary for the prevention and treatment of dental caries. In terms of preference for school dental clinic, the students from the school furnished with a dental clinic had a greater preference for that.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.40-40
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• 2010

산업현장에서는 파이프 또는 탱크류의 1GR용접에서 안정적인 이면비드를 가지는 루트패스 용접을 위해 2~3mm의 루트갭을 띄우고 용접봉 또는 필러와이어를 사용하는 TIG용접을 주로 한다. TIG용접은 고품질의 이면비드가 얻어지며, 용접인자의 제어가 쉽다는 장점이 있어 루트패스 용접에 많이 사용되고 있지만, 루트갭을 띄우면 이면비드는 잘 얻어지지만 용착금속량이 많아지게 되어 제작원가가 상승되고, 또한 소모성 와이어를 사용하는 GMAW에 비해 생산성이 낮다. 따라서, 안정적인 이면비드를 가지면서 생산성이 높은 1GR GMAW 루트패스 용접공정의 개발이 요구되지만, 이 경우도 루트갭이 2~3mm로 정해져 있으면 Fit-up공정에서 공수가 많이 필요하므로 근본적으로 루트갭이 없는 그루브에 대한 루트패스 용접이 더 바람직하다. 본 연구에서는 루트면 2.7mm를 가지는 U-그루브의 갭 없는 루트패스 용접에서 안정적인 이면비드가 형성되는 조건을 검토하기 위해 2.7t의 평판에 대하여 경사상진 각을 주고 기초 실험 후, U-그루브 맞대기 용접 실험을 진행하였다. 이 때, 경사상진 각은 용융금속이 중력으로 인해 아크 후방으로 밀리게 되고, 그로 인해 아크가 모재에 직접 닿게 되어 용입이 더 깊게되므로, 이면비드의 형성에 더 유리하다. 두께 2.7t의 연강 시편 2개를 갭 없는 I-그루브 맞대기 이음에서 Ǿ1.2 연강 솔리드 와이어를 사용하여 GMAW용접을 실시하였고, 용접전류, 용접속도, 경사상진 각, 위빙 폭, 위빙 주파수를 변경하여 각 조건에 대한 이면비드를 관찰하였다. 그 결과 경사상진 각 $25^{\circ}$, 전류 200A, 위빙폭 3mm, 위빙주파수 3Hz의 조건에서 안정적인 이면비드를 얻을 수 있었다. 또한, 현장에서 Fit-up중 발생할 수 있는 루트갭의 문제에 대하여 루트갭 1.2mm의 I-그루브 맞대기 용접에서 경사상진 각, 위빙 폭, 위빙 주파수는 갭 없이 실시한 실험에서 얻어진 가장 안정적인 결과를 사용하였고, 용접 전류, 용접 속도를 변경하여 이면비드를 관찰하였다, 그 결과 갭이 없을 때보다 약 80A 낮은 전류 조건인 120A에서 안정적인 이면비드를 얻을 수 있었다. 앞선 실험들을 기초로 하여 U-그루브 맞대기 용접을 실시 하였고, I-그루브 맞대기 용접에서 사용한 조건들과 유사한 용접 전류, 용접 속도에서 안정적인 이면비드를 얻을 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.6-13
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• 2010

In this study, Ga-doped ZnO (GZO) thin films have been fabricated on Eagle 2000 glass substrates at various substrate temperatures $100{\sim}400^{\circ}C$ and thin film thickness by RF magnetron sputtering in order to investigate the structural, electrical, and optical properties of the GZO thin films. It is observed that all the thin films exhibit c-axis orientation and a (002) diffraction peak only. The GZO thin films, which were deposited at $T=300^{\circ}C$ and 400 nm, shows the highest (002) orientation, and the full width at half maximum (FWHM) of the (002) diffraction peak is $0.4^{\circ}$. AFM analysis shows that the formation of relatively smooth thin films are obtained. The lowest resistivity ($8.01{\times}10^{-4}\;{\Omega}cm$) and the highest carrier concentration ($3.59{\times}10^{20}\;cm^{-3}$) are obtained in the GZO thin films deposited at $T=300^{\circ}C$ and 400 nm. The optical transmittance in the visible region is approximately 80 %, regardless of process conditions. The optical band-gap shows the slight blue-shift with increase in doping which can be explained by the Burstein-Moss effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.221-221
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• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.82-90
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• 2008

The generation amounts of manure and urine were total 4.57kg/head/d of 1.49kg manure/head/d and 3.08kg urine/head/d with consideration of 3 seasons and live weight. The finalized mean unit load generation of filth were estimated at BOD 199.5g/head/d, CODCr 413.5g/head/d, T-N 27.8g/head/d, T-P 5.3g/head/d with consideration of seasons and the type of stalls. The unit load generation of manure and urine from korean cow were analyzed as 10.9kg/head/day and 3.3kg/head/day, respectively. The unit load generation of manure from milch cow was analyzed to be 24.6L/head/day which was similar to the report of MOE(2006). The urine generation, 10.5L/head/day, was higher than the results from MOA(2000) and NIAR(2000), but was lower than the results from MOE(2006), NIER(1986) and KIST(1990). The unit load generation from egg layers estimated by discharged amount and concentration analysis increases in due to the difference of planting head numbers, feed stuffs and manure disposal. In case of deer unit load generation by herbivora were calculated to be higher than data from existing references because of the gap between weight per livestock and the generation amounts of manure and urine.