• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.73-86
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• 1997

This study was performed to assess the analyzing methods developed to detect clinically and quantitatively longitudinal bone changes. Through preliminary experiment, accuracy of Cu-Eq value conversion to the mass of HA was examined. For main experiment, 15 intraoral radiograms taken at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture in extracted sites of 3 cases were used. We took the radiograms with copper step wedge as test object and HA phantom X -ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner into computer were digitized and analyzed by NIH image program. The stability of the copper equivalent transformation and the usefulness of two analyzing methods by ROI and Reslice were examined. Obtained results as follows: 1) On the Cu equivalent images, the coefficient of variation in the measurement of Cu-Eq. value of ROI ranged from 0.05 to 0.24 and showed high reproducibility. 2) All results obtained by resliced contiguous image were coincident with those obtained from the assessment by ROI and formation of plot profile. 3) On the stacked and resliced image at the line of interest, we could analyze directly and quantitatively the longitudinal changes at several portions by plot profile and qualitatively by surface plot. 4) Implant area showed marked resorption till 2 weeks after implantation and showed significant increase in Cu-Eq. value at 6th week(p<0.01) and periapical area showed increase in Cu-Eq. value at 6th week compared to after-operation's.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.156-160
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• 2013

Objectives: Interest in bone graft material has increased with regard to restoration in cases of bone defect around the implant. Autogenous tooth bone graft material was developed and commercialized in 2008. In this study, we evaluated the results of vertical and horizontal ridge augmentation with autogenous tooth bone graft material. Materials and Methods: This study targeted patients who had vertical or horizontal ridge augmentation using AutoBT from March 2009 to April 2010. We evaluated the age and gender of the subject patients, implant stability, adjunctive surgery, additional bone graft material and barrier membrane, post-operative complication, implant survival rate, and crestal bone loss. Results: We performed vertical and horizontal ridge augmentation using powder- or block-type autogenous tooth bone graft material, and implant placement was performed on nine patients (male: 7, female: 2). The average age of patients was $49.88{\pm}12.98$ years, and the post-operative follow-up period was $35{\pm}5.31$ months. Post-operative complications included wound dehiscence (one case), hematoma (one case), and implant osseointegration failure (one case; survival rate: 96%); however, there were no complications related to bone graft material, such as infection. Average marginal bone loss after one-year loading was $0.12{\pm}0.19$ mm. Therefore, excellent clinical results can be said to have been obtained. Conclusion: Excellent clinical results can be said to have been obtained with vertical and horizontal ridge augmentation using autogenous tooth bone graft material.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.89-96
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• 2010

In this paper, we proposed a method about improving face tracking efficiency of face detection for AF system using the faces to the ROI. The conventional face detection system detecting faces based skin color uses the ratio of skin pixels of the present frame to detected face regions of the past frame to track the faces. The tracking method is superior in the stability of the regions but it is inferior in the face tracking efficiency. We proposed a face tracking method using the area of the overlapping region in the detected face regions of the past frame and the present frame to improve the tracking efficiency. The proposed face tracking efficiency demonstration was performed by making a film of face detection with face tracking in real-time and using the moving traces of the detected faces.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.2
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• pp.120-126
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• 2015

Recently, the ever-increasing use of fossil fuels for rapid industrial development and population significantly caused an environment pollution and global warming such as climate change. So research and development of sustainable and eco-friendly energy have been performed. Especially the interest in nuclear fusion fuel was significantly increased from the developed countries. The system of fusion energy production was tritium separation, storage and delivery, and purification. Republic of Korea is in charge of Storage and Delivery System (SDS) in the International Thermonuclear Experimental Reactor (ITER). Welding part of the SDS bottles for storing the tritium is known to be susceptible to hydrogen embrittlement. In this study, conducted a study for the relaxation of the stability and hydrogen embrittlement of the weld area. The hydrogen heat treatment was processed through the Pressure-Composition-Temperature (PCT) device according to the time variation. Also mechanical properties such as impact test and hardness test according to using the alkaline cleaning liquid for hydrogen embrittlement relief and the fracture was observed by scanning electron microscopy (SEM) after the mechanical properties evaluation.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.654-659
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• 2012

The interest in water gas shift (WGS) reaction has grown significantly, as a result of the recent advances in fuel cell technology and the need to develop small-scale fuel processors. Recently, researchers have tried to overcome the disadvantages of the commercial WGS catalysts. As a consequence, supported Pt catalysts have attracted a lot of researchers due to high activity and stability for WGS at low temperatures. In this study, $Pt-Na/Ce_{(1-x)}Zr_{(x)}O_2$ catalysts with various Ce/Zr ratio have been applied to WGS at a gas hourly space velocity (GHSV) of $45,515h^{-1}$. According to TPR patterns of $Pt-Na/Ce_{(1-x)}Zr_{(x)}O_2$ catalysts, the reducibility increases with decreasing the $ZrO_2$ content. As a result, Cubic structure $Pt-Na/Ce_{(1-x)}Zr_{(x)}O_2$ catalysts exhibited higher CO conversion than tetragonal structure $Pt-Na/Ce_{(1-x)}Zr_{(x)}O_2$ catalysts. Expecially, Pt-Na/$CeO_2$ exhibited the highest CO conversion as well as 100% selectivity to $CO_2$. Moreover, Pt-Na/$CeO_2$ catalyst showed relatively stable activity with time on stream. The high activity of cubic structure Pt-Na/$CeO_2$ catalyst was correlated to its higher oxygen storage capacity (OSC) of $CeO_2$ and easier reducibility of Pt/$CeO_2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.40-40
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• 2008

$InGaZnO_4$ based thin film transistors (TFTs) are of interest for large area and low cost electronics. The TFTs have strong potential for application in flat panel displays and portable electronics due to their high field effect mobility, high on/off current ratios, and high optical transparency. The application of such room temperature processed transistors, however, is often limited by the operation voltage and long-tenn stability. Therefore, attaining an optimum thickness is necessary. We investigated the thickness dependence of a room temperature grown $MgO_{0.3}BST_{0.7}$ composite gate dielectric and an $InGaZnO_4$ (IGZO) active semiconductor on the electrical characteristics of thin film transistors fabricated on a polyethylene terephthalate (PET) substrate. The TFT characteristics were changed markedly with variation of the gate dielectric and semiconductor thickness. The optimum gate dielectric and active semiconductor thickness were 300 nm and 30 nm, respectively. The TFT showed low operating voltage of less than 4 V, field effect mobility of 21.34 cm2/$V{\cdot}s$, an on/off ratio of $8.27\times10^6$, threshold voltage of 2.2 V, and a subthreshold swing of 0.42 V/dec.

• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.543-551
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• 2012

Objectives : School-age children have mixed dentition and are sensitive to dental caries. Their dental condition is more important as it is directly related with oral health in their life, and parents' attention and education are necessary as the children can not manage their oral health voluntarily. Methods : To evaluate the effect of parents' occupational status on the oral health of children, this study conducted a questionnaire survey and analyzed the results along with the results of oral examination with 952 students and their parents of an elementary school located in Ulsan conducting school oral health projects on May, 2009. Results : As dental caries prevalence rate recorded 33.7%, 56.8% and 66.9% in non-dual income, professional dual income and non-professional dual income families, respectively, the rate of children of dual income families was significantly higher than that of non-dual income ones (p<0.05). Conclusions : For professional dual income families, although working mothers contribute to economic stability, they took less time to care or to educate their children compared to no-working mothers so that they need to pay more attention to oral health of children. In addition, more interest to and education for children of non-professional dual income families showing relatively lower socio-economic level and lack of time for children, were also necessary in school projects on oral health education and prevention.

• Journal of Ocean Engineering and Technology
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• v.19 no.6 s.67
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• pp.35-43
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• 2005

Recently, various-shaped coastal structures have been studied and developed. Among them, the submerged breakwater became generally known as a more effective structure than other structures, bemuse it not only serves its original function, but also has the ability to preserve the coastal environment. Most previous investigations have been focused on the wave deformation and energy dissipation due to submerged breakwater, but less interest was given to their internal properties and dynamic behavior of the seabed foundation under wave loadings. In this study, a direct numerical simulation (DNS) is newly proposed to study the dynamic interaction between a permeable submerged breakwater aver a sand seabed and nonlinear waves, including wave breaking. The accuracy of the model is checked by comparing the numerical solution with the existing experimental data related to wave $\cdot$ permeable submerged breakwater $\cdot$ seabed interaction, and showed fairly nice agreement between them. From the numerical results, based on the newly proposed numerical model, the properties of the wave-induced pore water pressure and the flow in the seabed foundation are studied. In relation to their internal properties, the stability oj the permeable submerged breakwater is discussed.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.264-278
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• 2016

This study aims to examine the participation status and working conditions of seniors that participate in senior social activity support project, and analyze the influential relationship with subjective participation satisfaction based on participant attributes. In terms of the participation status, participating seniors became aware of the project through facilities and about 70% participated in the public interest type; the primary goal was for a short-term financial preservation. As an analysis result on participation effectiveness, longer participation period and time affected the participation seniors' working conditions and self-esteem negatively, implying that a flexible and effective operation of participation period is necessary. Also, while seniors with financial stability were more positively affected on their subjective satisfaction, other significant variables had negative effects. This study holds a significance in providing political implications as the basic data to improve and vitalize future senior social activity support project through the analysis of effectiveness, such as working conditions, self-esteem and subjective satisfaction based on participant attributes, including participant characteristics, participation status and participation degree.

• Journal of Korean Medical classics
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• v.24 no.5
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• pp.1-10
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• 2011

According to "Dongeuibogam(東醫寶鑑)", "the Shinnong Herb Bible(神農本草經)", "Chamdonggo(參同攷)", come to the conclusion about medical thought of "the Zhouyi Cantongxie(周易參同契)". Alchemy is a common field both on the eastern and western civilization, but a process of development is different. Ancient chinese alchemist made a study on external alchemy, but harmful consequences of external alchemy was consecutive, many scholars had turned their interest on internal alchemy which is related in human meridian biology and spirit. In the western alchemy has developed to make a study on analytic psychology and science of religion. Most importantly, the eastern and western alchemy have something in common what at the point of the perfection of self is similar, but the name is different, for example in the eastern alchemy we can be immortals and take a spiritual enlightenment with the elixir of life, in the western we can take a cure of souls as a christian. As for internal alchemy, "Cantongxie(參同契)" gives influence to the theories such as the theory of danjeon(lower part of the abdomen), evolution, aging, and life nurturing. Especially, the theory of danjeon shows such merit for studying since it is similar to triple energizers(三焦) and the theory of qi street(氣街) of oriental medicine. The study on "Cantongxie(參同契)" was achieved in Korea too, especially Chosun dynasty. "Candongkao (參同攷)" by Seo Myung-eung(徐命膺, 1716~1787) are representative. According to "Candongkao(參同攷)", Geon(乾), Gon(坤), Gam(坎), and Ri(離), the four trigrams for divination, each are affiliated with lungs, spleen, kidneys, and heart. Nowadays the study on alchemy correspond with modern trends, which are anti-aging and living without any disease. If processed mineral drugs is assured for stability, it can be used for incurable diseases such as cancer.