극자외선 리소그래피에서 마스크 결함에 의한 이미지 특징

유명슬,박승욱,김옥경,오혜근 한양대학교 이학기술연구소 2004 이학기술연구지 Vol.7 No.

본 논문에서는 극자외선(Extreme-Ultraviolet) 리소그래피에서 사용되는 마스크 특성을 알아보았다. EUV 마스크는 Mo 와 Si 이 각각 2-4㎚ 정도의 두께로 쌓이기 때문에 공정상에 결함이 발생할 소지가 다. 전산 모사를 통해 마스크 상에 결함이 없을 때와 여러 가지 결함 조건 이 있을 때 웨이퍼 상에 전사되는 이미지 변화를 알아보았다. 결함의 조건에 의해 이미지 대조비 (Contrast), 폭(Width) 변화가 나타났으며 또한 이미지의 상 일그러짐과 최대 세기 위치 이동을 관찰 할 수 있었다. Simulation has been used to predict aerial images for masks with defect-free multilayer and with defect in multilayer. Mask defects are easily produced in an extreme-ultraviolet lithography mask fabrication process, because 80 Mo/si multilayer films are stacked and each stack is made from 2 to 4㎚. In this case, the multilayer can be stacked with defects and with slightly different heights. It is difficult to achieve an aerial image which is desired. This paper discusses various image properties when there is no defect and when there are different kinds of defects in the multilayer. The results are calculated by using SOLE-EUV of Simga-C. A finite-difference time-domain algorithm is used, and the aerial images caused by defects in the multilayer are also characterized.

타이어 편마모 해소를 위한 최적차량 구조설계

최종근,김명규,최석환 도립 강원전문대학 1998 道立 江原專門大學 論文集 Vol.1 No.1

This paper has been studied to eliminate the wear of tire on the solid axle type of an automotive. The heavy tracks, different from passenger cars, have a front axle which consists of a solid axle in a shape of I-beam. Therefore, it is difficult to change the fixed angle of camber and king pin once they are assembled. This study has introduced a suitable method to remove the uneven wear of tire by combination of camber and king pin angle at the stage of design. Parametric optimization has been carried out by setting the optimum characteristics for static and dynamic analysis. The static characteristics represents a condition where the tire and ground makes a perpendicular angle, which makes the ground camber to be zero. The optimal dynamic condition is to minimize the lateral force between the tire and ground in dynamic simulations.

가상기준점측량을 이용한 도시기준점 분석

최석근, 안원태, 박명진 충북대학교 건설기술연구소 2008 충북대학교 건설기술연구소 논문집 Vol.27 No.1

Realtime Kinematic(RTK) method make decision to correct position by calculating correction value of rover and transmitting to rover data from GPS base station. However. this method has many problems as it required base station and rover. Also lots of time for setting, commit workers and many equipment were needed. Therefore, in this study, we made system using virtual reference station and analysed the accuracy of urban control point through VRS RTK method without limited time and distance. As result of this study, two control points were obtained with good results in expected accuracy, therefore it was good method for management of urban control point. Also, it was useful to reconstruct control point immediately and to build urban information system.

부영양화 방지를 위한 정석탈인법의 응용성 제고 연구

윤명희,김소연,왕창근 忠南大學校 環境問題硏究所 2002 環境硏究 Vol.20 No.-

The purpose of this study is to develop phosphorus removal technology by crystallization on various materials for prevention eutrophication. This study was based on precipitation mechanism and was performed to see phosphorus removal efficiency of activated carbon, anthracite, aluminium and wasted concrete etc. The results obtained from this study are following ; The granular activated carbon coated with dissolved clamshell showed good removal efficiency, 82% of phosphorus. For anthracite after coating, 49% of phosphorus was removed. Other materials such as aluminium and wasted concrete could remove 40% and 48% of phosphorus, respectively. Judging from the results from this research, this technology can be applied for prevention of eutrophication and algal bloom in the lakes.

금성산의 곤충상에 관한 연구

김재근,주명칠 동신대학교 환경연구소 2000 환경연구 Vol.5 No.1

A faunistic study on the terresterial insects (except soil insects) of Galma Mt. was carried out during march to November in 2000 year. The area is located in the boundary between Naju-si and Kwangjoo-si province of the central part of Chonnam which is composed of the main peak(alti. 450m) and other peakes. The results obtained as follows; 1. The terrestrial insects collected and identified from this area are composed of 86 species of 49 families of 10 orders from Keumseong Mt. in 2000 year. 2. The collected species are many of ordonata, coleoptera, diptera and lepidoptera. 3. The collected families are many of coleoptera, diptera and lepidoptera. 4. The collected individuals are very many of Cicadalla virids of cicadellidae of homoptera.

수 종의 생약제제가 human fetal osteoblasts의 염기성 인산분해 효소 활성에 미치는 영향

이명구,유형근 원광대학교 치의학연구소 2003 圓光齒醫學 Vol.12 No.2

Several growth factors and polypeptides are not commonly yet used for regenerators of bone tissue or alveolar bone because of the insufficiency of studies on their side effects, genetic engineering for mass production and stability for clinical application. Recently, many herbal medicines, which have advantage of less side effects and possibility of ling-term use, have been studied for their capacity and effects of anti-bacterial, anti-inflammatory and regenerative potential of periodontal tissues. Morindae Radix, Cibotium Barometz (L.), Albizziae Cortex, Cistandhis Herba have been traditionally used as medicines for treatment of bone disease in Eastern medicine. The objective of the present study is to examine the ability of alkaline phosphatase (ALP) activity of human fetal osteoblast (hFOB1) when several natural medicines were supplemented. hFOB1 were cultured with Dulbecuo's Modified Eagle's Medium Nutrient Mixture F-12 HAM ( DMEM/F-12 1:1 Mixture, Sigma, USA) and negative control, dexamethasone (positive control), and each natural medicines for 3 days. And then ALP activity was measured by spectrophotometer for enzyme activity and Alizarin red S staining for morphometry. Among the natural medicines of this study, Morindae Radix, Cibotium Barometz (L.) and Cistanchis Herba induced higher activity of ALP systhesis than negative controls in all experimental group. Albizziae Cortex showed mild increases than negative control group. According to measurement of positively stained area, all of the natural medicines of this study increased compared to negative control. Especially, Cibotium Barometz (L.) and Cistanchis Herba showed statistical significance compared to negative control (p<0.05). These results indicate that Morindae Radix, Cibotium Barometz (L.), Albizziae Cortex, Cistandhis Herba have an inducing ability of ALP synthesis on osteoblast.

타이타늄 임플란트와 상부구조물의 갈바닉 쌍의 전기화학적 특성

오근택,김명화,최병갑,김경남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.1

For the aesthetic and functional restoration of edentulous patients, recently dental implants have been used widely. Dental implants and restorative alloys are required with the high corrosion resistance. Suprastructure and implant with different compositions, which are in electrical contact, may develop galvanic or coupled corrosion problems. Besides galvanic corrosion, crevice and pitting corrosion may occur in the marginal gap or the gap between dental implant assemblies. In this study, Ti implants, gold, silver-palladium, cobalt-chromium and nickel-chromium suprastructures were used to investigate their galvanic and crevice corrosion of suprastructure/Ti implant couples. Potentiodynamic and potentiostaic testing were performed in artificial saliva at 37℃. Potentiodynamic testing was carried out at the potential scan rate of 1 ㎷/sec and in the range of -600∼1600 ㎷(SCE). Potentiostatic testing such as open circuit potential and current densities at -250, 0 and 250 ㎷(SCE) was performed for 5000 seconds in artificial saliva. After electrochemical testing, the surface and cross-sectional morphologies of the samples were observed using optical microscopy. Potentiodynamic test results indicated that suprastructure/Tim implant couples exhibited the passive current density range of 0.5∼12 ㎂/㎠, Ti abutment/Tim implant and gold/Tim implant couples exhibited relatively low passive current density, Co-Cr/Tim implant couples the highest. Co-Cr and Ni-Cr/Tim implant couples showed the breakdown potentials of 700 and 570 ㎷(SCE), respectively. Open circuit potentials of silver, Ti abutment, gold, Ni-Cr and Co-Cr/Ti implant couples were -93.2±93.9, -123.7±58.8, -140.0±80.6, -223.5±35.1, and -312.7±29.8, respectively and stable according to immersion time. The couples exhibited cathodic current densities at -250 ㎷(SCE), especially, gold and silver alloys showed the high cathodic current densities of ±3.18 and ±6.63 ㎂/㎠, respectively. At 250 ㎷(SCE), Ti abutment/Ti implant couples exhibited the lowest current density of 9.48×10^-2 ㎂/㎠, and gold, Ni-Cr, Co-Cr and silver/Ti implant couples exhibited 0.313, 1.27, 5.60 and 8.06 ㎂/㎠, respectively. The couples exhibited relatively low current densities at 0 ㎷(SCE). The photographs after electrochemical testing showed crevice or pitting corrosion in the marginal gap and suprastructure surface. Although Co-Cr/Ti implant couples among the tested samples had the possibility of the galvanic corrosion, its degree was not significant.

오리알의 卵黃, 卵白 및 卵殼중 微量鑛物質의 含量分布에 관한 硏究

이명헌,김상근,이종진 충남대학교 수의과대학 동물의과학연구소 1994 動物醫科學硏究誌 Vol.2 No.-

This study was to assayed 9 trace minerals of Ca, P, K, Na, Mg, Fe, Zn, Cu, Mn in duck's egg yolk, egg white and egg shell by with Inductively Coupled Argon Plasma(ICAP). The results summarized as follows: 1. The levels of Ca, P, K, Na, Mg in duck's egg yolk, egg white and egg shell were 747.9ppm, 2216.6ppm, 620.0ppm, 345.5ppm, 30.9ppm and 52.9ppm, 136.5ppm, 1127.2ppm, 1638ppm, 69.1ppm and 220ppm, 814.6ppm, 298.0ppm, 535.2ppm, 812.2ppm, 1447.8ppm, respectively. The levels of K and Na of duck's egg are the highest compared with that of another constituents in eggs. 2. The levels of Fe, Zn, Cu, Mn in duck's egg yolk, egg white and egg shell were 22.7ppm, 14.3ppm, 0.98ppm, 0.25ppm and 5.0ppm, 0.29ppm, 0.48ppm, 0.02ppm and 3.4ppm, 2.1ppm, 0.96ppm, 0.56ppm, respectively.

무선 인터넷 기반의 POI 정보 서비스를 위한 개인 항법 시스템 브라우저 구현

이근,엄유열,최명환,박홍성 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

This paper presents a design and implementation of a Personal Navigation System Browser for POI services for portable PDA(Personal Digital Assistants). Personal Navigation System(PNS) service is a location based geographic information service for PDA or cellular telephone. Point of Interest(POI) is the information about a user's personal interests. PNS Browser is a PNS application which receives and displays POI information as well as location based geographic information service. In this paper, a PNS Browser is proposed and its implementation is presented that contains CHtml Web Browser and POI manager as well as the Map display by using wireless internet technology.

자체정열 방법을 이용한 GR(Gate-Recessed) SOI

이충근,한명석,홍신남 한국항공대학교 1997 論文集 Vol.35 No.-

SOI(Silicon-On-Insulator)소자는 집적도의 향상, 단채널 효과의 감소, 임계전압 이하에서 기울기 향상, 높은 이동도, latch-up 제거 등의 우수한 이점을 제공한다. 그러나 SOI소자는 current kink와 early breakdown과 같은 floating-body effect를 나타낸다. Floating-body effect를 줄이기 위해 fully depleted SOI를 사용해야 하나 면저항이 크기 때문에 GR(gate-recessed) SOI가 제안되었다. GR SOI는 floating-body effect와 면저항을 줄일 수 있지만 공정상 복잡성이 따른다. 이 논문에서는 self-alignment method를 이용한 GR SOI 를 제안하여 이러한 문제를 해결하였다. 제안되 구조를 시뮬레이션한 결과 드레인 전류의 크기 향상, floating-body effect제거를 위한 imapct-ionization current를 감소시킬 수 있었다. SOI(Silicon-On-Insulator) devices offer unique advantages such as reduction in short channel effects, improvement of subthreshold slope, higher mobility, latch-up free nature and so on. But these devices have two problems; floating-body effect causing current kink and early breakdown effect. Fully depleted SOI reduces floating-body effect, but it increases sheet resistances. So gate-recessed SOI is proposed. Gate-recessed SOI can reduce sheet resistance and floating-body effect, but is processing step are complicated. In this paper, gate-recessed SOI using selt-alignment method is proposed to solve the above problems. Proposed structure improved drain current level, decreased sheep resistances of sourcd/drain regions and impact ionization current for removal floating-body effect