이온빔 보조 전자빔 수산화 인회석 증착이 골내 임플란트의 골유착에 미치는 영향

정영철,한종현,이인섭,이현정,김명호,Jung, Young-Chul,Han, Chong-Hyun,Lee, In-Seop,Lee, Hyeon-Jeong,Kim, Myeong-Ho 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.5

A large increase in the use of thin film coating of hydroxyapatite(HA) in implant dentistry is driven by the desire to take advantage of the excellent biocompatibility and high strength of HA coating. The purpose of this study was to evaluate the effects of HA-coated implants by ion Beam Assisted Deposition(IBAD) method in comparison to the sand-blasted and machined surfaces. Osteoblast culture test, removal torque test and histomorphometric analysis were performed and the following results obtained; 1. Examination of the osteoblast cultures displayed no difference in the secretion of alkaline phosphatase between the various specimen, but IBAD with pure HA specimen showed low alkaline phosphatase secretion(p<0.05). 2. Removal torque tests showed HA-coated implants by IBAD method to be similar in high value to the implants with sand-blasted surface than the implants with machined surface. And the ovariectomized group showed low mechanical test value than the normal group(p<0.05). 3. Histomorphometrical comparisons were performed on undecalcified ground sections. HA-coated implants by IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and 3-best consecutive threads, and the implants with sand-blasted surface and implants with machined surface was in the next consecutive order(p<0.05). HA-coated implants showed slightly higher bone-to- metal contact ratio than sand-blasted implants, but no statistically significant difference was obtained between the two materials. The ovariectomized group showed lower value of bone-to-metal contact ratio than the normal group, but no statistically significant difference was obtained between the two groups. 4. Evaluation of bone volume on all threads and 3-best consecutive threads showed no statistically significant difference among the different surface treatment groups, but showed lower bone volume in ovariectomized group than in the normal group(p<0.05). According tn these results, thin film coated implants with HA showed high bone contact ratio, bone volume and removal torque strength in the short term, but long term observation is needed.

보호용 실리콘 산화막을 이용하여 제조된 $Al_2O_3$ 예비층이 초박막 ${\gamma}-Al_2O_3$ 에피텍시의 성장에 미치는 영향

정영철,전본근,석전성,Jung, Young-Chul,Jun, Bon-Keun,Ishida, Makoto 한국센서학회 2000 센서학회지 Vol.9 No.5

In this paper, we propose the formation of an $Al_2O_3$ pre-layer using a protective Si-oxide layer and Al layer. Deposition of a thin film layer of aluminum onto a Si surface covered with a thin Si-oxide layer and annealing at $800^{\circ}C$ led to the growth of epitaxial $Al_2O_3$ layer on Si(111). And ${\gamma}-Al_2O_3$ layer was grown on the $Al_2O_3$ per-layer. Etching of the Si substrate by $N_2O$ gas could be avoided in the initial growth stage by the $Al_2O_3$ pre-layer. It was confirmed that the $Al_2O_3$ pre-layer was effective in improving the surface morphology of the very thin ${\gamma}-Al_2O_3$ films. 본 논문에서는 보호용 실리콘 산화층과 Al 층을 이용한 $Al_2O_3$ 예비층의 형성을 제안하였다. 실리콘 기판 위의 보호용 산화막 위에 알루미늄을 증착하고 이를 $800^{\circ}C$에서 열처리함으로써 에피텍시 $Al_2O_3$ 예비층 형성시킬 수 있었다. 그리고 형성된 $Al_2O_3$ 예비층위에 ${\gamma}-Al_2O_3$ 층을 형성하였다. ${\gamma}-Al_2O_3$막 성장시 공정의 초기 상태에서 발생하는 $N_2O$ 가스에 의한 Si 기판의 식각을 $Al_2O_3$ 예비층을 이용함으로써 방지할 수 있었다. $Al_2O_3$ 예비층이 초박막 ${\gamma}-Al_2O_3$의 표면의 형태를 개선하는데 많은 효과가 있었다.

건축공사 주요자재별 에너지소비량 및 CO₂ 배출 원단위 값 산출에 산업연관표 적용 적정성 검토 연구 -2005년, 2007년 산업연관표를 중심으로-

정영철,김성은,장영준,김태희,김광희,Jung, Young-Chul,Kim, Sung-Eun,Jang, Young-Jun,Kim, Tae-Hui,Kim, Gwang-Hee 한국건축시공학회 2011 한국건축시공학회지 Vol.11 No.3

한국은행에서 2000년도에 발행된 산업연관표를 적용한 주요 건축자재의 에너지소비량과 $CO_2$ 배출에 대한 원단위 DB는 있지만 2005년, 2007년에 발행된 산업연관표를 이용한 원단위 DB는 없는 실정이다. 본 연구에서는 최근에 발행된 2005년, 2007년도 산업연관표를 이용하여 주요 건축자재에서 발생되는 에너지소비량 및 $CO_2$ 배출 원단위 값을 산정하고자 한다. 주요 건축자재의 에너지소비량 및 $CO_2$ 배출원단위 산출을 위한 방법은 산업연관표를 이용한 DB 구축 방식을 바탕으로 산출하였으며, 건설현장에서 주로 사용되는 16가지의 건설자재는 선별하여 적용하였다. 기존 연구결과에서 제시한 2000년도 산업연관표를 적용하여 산출된 원단위 DB 값과 비교한 결과 근소한 차이를 보이고 있어 본 연구의 산출방법이 적정한 것으로 판단하였다. 2005년, 2007년도 산업연관표를 이용하여 산출한 에너지소비량과 $CO_2$ 배출 원단위 값은 감소세를 보이고 있는 것으로 나타났으며, 시멘트와 철근을 주원료로 하는 자재에서 가장 많은 에너지소비량 및 $CO_2$ 배출 원단위 값을 나타났다. 본 연구의 결과를 통해 국내 실정에 적합한 건설자재 생산단계에서 발생되는 환경부하의 간접적인 예측이 가능할 것으로 사료된다. Currently, there is database for per unit requirements of major construction materials in terms of energy consumption and $CO_2$ emission based on the input-output table published by the Bank of Korea in 2000, but no database for per unit requirements based on input-output tables was published in 2005 and 2007. The purpose of this study was to calculate the unit requirement values of major construction materials in terms of energy consumption and $CO_2$ emission generated by using the input-output tables published in 2005 and 2007. To estimate the unit requirement values, a database building method with the input-output tables was adopted by selecting 16 types of construction materials in wide use on construction sites. When the study results were compared with existing unit requirement values based on the input-output table of 2000, there were small discrepancies, from which it can be interpreted that the method used in the study is reasonable. Unit requirement values estimated based on input-output tables of 2005 and 2007 tended to decrease, and the highest value of energy consumption and $CO_2$ emission were found in the materials using cement and rebar.

치근형 골내 임플란트의 초기 1년간 치조골 소실 및 골 밀도 변화에 관한 연구

정영철,한종현,이근우,Jung Young-Chul,Han Chong-Hyun,Lee Keun-Woo 대한치과보철학회 1994 대한치과보철학회지 Vol.32 No.3

Regular radiographic examination has been considered an essential diagnositic method for osseointegrated dental implantation. This study investigated marginal bone loss through the measurement on periapical radiographs and changes in bone density through digital subtraction image radiographic method around 88 endoseous root-form dental implants in 43 human subjects. Four types of endosseous dental implants were investigated : Standard series, Mini series and Hex-lock system of Steri-Oss Dental implant system, and $Br{\aa}nemark$-type implant from 3i dental implant system, in a 3 month interval for a total period of 12 months. The results were as follows : 1. Rapid bone loss occurred in the first 3 months in all 4 groups, and the bone level stabilized at the first thread of the implant fixtures. Amount of bone loss for 12 months showed correlation with the length of the polished neck portion. 2. Most of the implant systems showed resorption of alveolar bone up to the polished neck portion although a long polished neck could delay the resolution. 3. Alveolar bone loss apical to the polished neck portion stabilized at the first thread of the fixtures with no correlation to either the time of exposure of the polished neck or types of implant systems. 4. No changes in bone density around the implant threads were observed throughout the experimental period. Bone density decreased at the marginal bone, and increased at the newly-formed alveolar crest. These results indicate that most of the alveolar bone loss occur within the first 12 months after installation of endosseous root-form dental implants resulting in the exposure of polished neck portions, and the bone level stabilizes thereafter at the first thread portions of the implant fixtures. The experimental period of 12 months seems insufficient for observing changes in bone density, and a long-term observation should be needed.

노이즈 감소 필터 사용이 판독능에 미치는 효과

정영철,최보람,허경회,이원진,허민석,이삼선,최순철,Jung, Young-Chul,Choi, Bo-Ram,Huh, Kyung-Hoi,Yi, Yon-Jin,Heo, Min-Suk,Lee, Sam-Sun,Choi, Soon-Chul 대한영상치의학회 2010 Imaging Science in Dentistry Vol.40 No.3

Purpose : This study was performed to examine the effects of image filter on observer performance by counting the number of holes at each wedge step on a radiographic image. Materials and Methods : An aluminum step wedge with 11 steps ranged in thickness from 1.5 mm to 16.5 mm in 1.5 mm increments was fabricated for this study. Each step had 10 notched holes with 1.0 mm diameter on the bottom of the step wedge which were ranged in depths from 0.1 mm to 1.0 mm in 0.1 mm increments. Digital radiographic raw images of the aluminum step wedge were acquired by using CCD intraoral sensor. The images were processed using several types of noise reduction filters and kernel sizes. Three observers counted the number of holes which could be discriminated on each step. The data were analyzed by ANOVA. Results : The number of holes at each step was decreased as the thickness of step was increased. The number of holes at each step on the raw images was significantly higher than that on the processed images. The number of holes was different according to the types and kernel sizes of the image filters. Conclusions : The types and kernel sizes of image filters on observer performance were important, therefore, they should be standardized for commercial digital imaging systems.

보호용 실리콘 산화막을 이용하여 제조된 Al2O3 예비층이 초박막 γ - Al2O3 에피텍시의 성장에 미치는 영향

정영철(Young Chul Jung),전본근(Bon Keun Jun),석전성(Makoto Ishida) 한국센서학회 2000 센서학회지 Vol.9 No.5

N/A In this paper, we propose the formation of an Al₂O₃ pre-layer using a protective Si-oxide layer and AI layer. Deposition of a thin film layer of aluminum onto a Si surface covered with a thin Si-oxide layer and annealing at 800 ℃ led to the growth of epitaxial Al₂O₃ layer on Si(111). And γ-Alzoa layer was grown on the Alzoa per-layer. Etching of the Si substrate by N₂O gas could be avoided in the initial growth stage by the Alms pre-layer. It was confirmed that the Al₂O₃ pre-layer was effective in improving the surface morphology of the very thin γ-Al₂O₃ films.

북한의 지방체제 -계획된 자립체제에서 강제된 자립체제로

정영철 ( Young Chul Jung ) 민주사회정책연구원 2002 민주사회와 정책연구 Vol.2 No.-

North Korea unlike western societies doesn`t possess a local autonomical system, because the politics and the administration are organized and practiced by the principle of democratic centralism. Local autonomy in North Korea performs its function and role as a channel to convey and execute party policies and decisions of supreme leaders. Its organizations and administrative districts have been reorganized several times to improve its function more effectively since the 1945 Liberation. The peculiarity of its reorganization is to reform the administrative system from four-tier to two-tier, to divide or to integrate administrative districts into smaller ones, and to except a Ri(the smallest administrative unit) from the administrative system to function as an unit of production. The reasons why North Korea has reorganized administrative districts frequently are to overcome a defect of bureaucracy and improve its efficiency and to strengthen the leadership for the development of local economy. Local system in North Korea has been converted to self-reliance system since the 1960s. North Korea has formulated ``self-reliance`` system and worked out a strategy of the development in local economy around a ``Kun``(a county). The strategy around a ``Kun`` primarily has been performed under military purposes of industrial relocation and raising of local industry for autarky around a ``Kun`` in time of emergency. Since 1973, local budget system has been implemented, which has supported local self-reliance institutionally. Local self-reliance system at that time was progressed intentionally from the top. Planned self-reliance system, however, was converted to forced self-reliance system by collapse of socialism and North Korea`s crisis late in the 1980s. Local government was demanded to make an effort for themselves for each survival in the weakening of state capability. These changes resulted in the weakening of central control and the increase of local autonomy, but local autonomy failed to connect with political one. In 1998, as the turning point, North Korea integrated state control to forced self-reliance system: State control was strengthened, on the other hand, local initiative and positiveness were demanded much more. The constitution and People`s Planned Economy Act in 1998 were to institutionalize re-establishment of state control to forced self-reliance system. Now, there is laid relationship between central and local government in North Korea on the fork of serious change. Like Chinese experience, reform and opening in North Korea are accompanied necessarily by local decentralization and increase of autonomy, thus, a new relationship between two will be expected in the process of reform and opening.

논문 : 센서 재료 , 제조공정 및 기타 : 보호용 실리콘 산화막을 이용하여 제조된 Al2O3 예비층이 초박막 r - Al2O3 에피텍시의 성장에 미치는 영향

정영철(Young Chul Jung),전본근(Bon Keun Jun),석전성(Makoto Ishida) 한국센서학회 2000 센서학회지 Vol.9 No.5

환경계획재량의 통제규범으로서의 형량명령

정영철(Jung, Young-Chul) 한국비교공법학회 2013 공법학연구 Vol.14 No.4

지역통상정보 : VECM을 이용한 한국 외국인직접투자와 인적자본의 경제성장 효과

정영철 ( Young Chul Jung ),김성기 ( Seong Ki Kim ),서민교 ( Min Kyo Seo ),강한균 ( Han Gyoun Kang ) 한국통상정보학회 2012 통상정보연구 Vol.14 No.1

외국인직접투자가 현지국 경제성장에 어떠한 영향을 미치는가에 대한 논란은 시대적으로 적지 않은 논란이 되기도 하였다. 본 연구에서는 한국의 외국인직접투자가 경제성장에 미치는 효과를 분석의 대상으로 하였고 VECM을 이용한 실증분석 결과를 중심으로 다음과 같이 결론을 요약하고 시사점을 도출하고자 한다. 첫째 한국의 외국인직접투자가 지난 40년 동안 한국의 경제성장에 어떠한 영향을 미쳤으며 어느 정도의 기여를 하였는가를 시계열 자료를 이용하여 다양한 방법으로 분석하였다. 둘째 한국 외국인직접투자에 대학 취업자의 구성 비율을 곱한 상호작용 효과 변수(EDUF)를 고려한 충격반응함수에서는 2기에서 3기까지의 일시적 감소를 제외하고는 양(+)의 영역에서 지속적으로 증가하는 추세를 유지하였고 FDI만을 고려한 충격반응함수 보다 경제성장에 미치는 효과도 크고 지속적인 것으로 나타났으나 그 효과가 그다지 크지는 않았다. 끝으로 시사점으로 한국은 외국인직접투자 유치잠재력은 높으면서도 실제 외국인직접투자의 총 유입액이 많지 않아 경제성장에 미친 영향은 크지 않았다. The purpose of this paper is to analyze the economic effects of Foreign Direct Investment (FDI) and human capital using VECM in Korea from 1970 to 2009. Empirical results through VECM show that the coefficients of GDP, GFO (gross fixed capital), LAB (total labor), EXO (export), PCDB (public and commercial loan) and FDI have had a positive impact on Korean economic growth. In contrast, the effects of PCDB and FDI were not as significant as the other variables. In particular, the interaction effect, FDI*EDU (the college graduation variable), was more important than that of the FDI alone. However, the coefficient of FDI*EDU was not so big. Korean government needs to attract more FDI to enhance Korean economic growth rate by the improvement of investment environment. There are a big amount gap between notification FDI and arrival FDI in Korea, So Korean government and companies should actively persuade foreign investors to invest after their investment notification. Also the Korean college authorities should emphasize more on curriculum which adapts to company skill in the field work.