• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.22-24
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• 2002

이동 IP 망에서 이동 IP의 삼각 라우팅 문제를 해결한 최적경로 IP 라우팅 기법은이동 IPv6망에서의 이동성을 지원하는 기본 동작으로 되어있다. 본 논문에서는 이동 IP망의최적 경로 기법을 NBMA망에서의 NHRP를 이용한 단거리 터널설정 기법을 적용하여 그 성능을 평가하였다. 패킷 전달지연 시간 측면에서 기존 IP 라우팅 기법과 최적 경로에서의단거리 터널링 기법을 상호 비교하기 위하여 수학적 분석 및 모의실험을 수행하였다. 최적경로의 단거리 터널링 기법은 기존 IP 라우팅 방식보다 초기 데이터의 경우 종단간 전달 지연시간이 클 수 있으나 이후 패킷부터는 종단간 데이터 전달 지연시간이 대폭 개선됨을 확인하였다.

• 기계와재료
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• v.21 no.4
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• pp.96-105
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• 2010

도로 및 철도는 차량의 고속화와 신속한 물류의 유통을 위해 직선 및 수평화가 절실하게 요구되며, 국내 건설구간의 약 50~70%가 산악지형으로서 터널공사가 필수적으로 요구된다. 국내터널굴착은 주로 발파에 의한 NATM(New Austrian Tunneling Method)으로 공사가 이루어지고 있으나, 굴착효율이 낮으며 안전사고의 위험성이 높다. 해외에서는 급속한 시공을 위하여 TBM(Tunnel Boring Machine)의 적용 사례가 증가하고 있다. 그러나 국내에는 TBM에 대한 연구가 전무한 상태이고, TBM 터널의 설계 시공 기술과 경험이 미흡하다. 최근 대도시의 지하터널과 장대터널의 수요가 증대되어 TBM터널시공 기술과 TBM장비의 국산화가 절실하게 요구되고 있다. 본고에서는 국내외 주요 TBM 시공현황과 전망을 정리하여 TBM 터널 기술의 확보가 매우 시급함을 상기시키고자 하였다.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.85-88
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• 2007

Ab initio periodic Hartree-Fock calculations with the full potential and minimum basis set are applied to interpretation of scanning tunneling microscope (STM) and atomic force microscope (AFM) images on 1TVTe2. Our results show that the simulated STM image shows asymmetry while the simulated AFM image shows the circular electron densities at the bright spots without asymmetry of electron density to agree with the experimental AFM image. The bright spots of both the STM and AFM images of VTe2 are associated with the surface Te atoms, while the patterns of bright spots of STM and AFM images are different.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.759-766
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• 2002

In the paper the authors describe the development of ITIS(Intelligent Tunneling Information System) for the Purpose of applying the 3D visualization technique, GIS, AI(Artificial Intelligence) to tunnel design and construction. VR(Virtual Reality) and 3D visualization techniques are applied in order to develope the 3D model of characteristics and structures of ground and rock mass. Database for all the materials related to site investigation and tunnel construction is developed using GIS technique. AI technique such as fuzzy theory and neural network is applied to predict ground settlement, decide tunnel support method and estimate ground and rock mass properties according to tunnel excavation steps. ITIS can help to inform various necessary tunnel information to engineers quickly and manage tunnel using acquired information based on D/B.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.3
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• pp.58-62
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• 2001

Since Metallo-Porphyrin (MP) is very interesting compound due to its unique electronic and redox properties and it is also chemically and thermally stable, MP has been studied for potential memory and switching devices. In this study, thin films of 5,10,15,20-Tetrakis-Octadecyloxymethylphenyl-Porphyrin-Zn(II) were prepared by the Langmuir-Blodgett (LB) method and characterized by using UV/vis absorption spectroscopy and cyclic voltammetry. It was found that the proper transfer surface pressure for film deposition was 25 mN/m and the limiting area per molecule was 135 ${\AA}^2$/molecule. The current-voltage (I-V) characteristics of these films were investigated. Further details on the electrical properties of Porphyrin-Zn(II) derivative films will be discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.9 s.252
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• pp.1094-1101
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• 2006

Recently, a ultra-precision stage is widely used in the fields of the nano-technology, specially in AFMs(Atomic Force Microscope) and STMs(Scanning Tunneling Microscope). In this paper, the ultra-precision stage which consists of flexure hinges, piezoelectric actuator and ultra-precision linear encoder, is designed and developed. The system transfer function of the ultra-precision stage system was derived from the step responses of the system using system identification tool. A $H_{\infty}$ controller was designed using loop shaping method to have robustness for the system uncertainty and external disturbances. For the designed controller, simulations were performed and it was applied to the ultra-precision stage system. From the experimental results it was found that this stage could be controlled with less than 5nm resolution irrespective of hysteresis and creep.

• Journal of Surface Science and Engineering
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• v.29 no.5
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• pp.314-324
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• 1996

Scanning probe microscopes (SPMs) such as the scanning tunneling microscope (STM) and the atomic force microscope (AFM) were used for surface modification tools at the nanometer scale. Material surfaces, i. e., titanium, hydrogen-terminated silicon and trimethylsilyl organosilane monolayer on silicon, were locally oxidized with the best lateral spatial resolution of 20nm. The principle behind this proximal probe oxidation method is scanning probe anodization, that is, the SPM tip-sample junction connected through a water column acting as a minute electrochemical cell. An SPM-nanolithogrphy process was demonstrated using the organosilane monolayer as a resist. Area-selective chemical modifications, i. e., etching, electroless plating with gold, monolayer deposition and immobilization of latex nanoparticles; were achieved in nano-scale resolution. The area-selectivity was based on the differences in chemical properties between the SPM-modified and unmodified regions.

• Economic and Environmental Geology
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• v.32 no.6
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• pp.661-667
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• 1999

Estimation of inflow rates into subsection of a tunnel is establishing the proposed grouting part, measuring the degree of grouting, and settling the dispute over deplrtion of groundwater which may be resulted from tunneling. A current meter was used to calculate inflow rates of groundwater to each subsection of the tunnel. The study area is composed of section 1 and 2 of Imha-Youngchun waterway trnnel which has 32.976km length, with each section having 3,745m and 4,079m, respectively. The depth from groung surface to tunnel ranges from 122.45m to 358.3m. Total inflow rates of groundwater into each section measured three times by the current meter, together with bottle and eye measurement, were compared with groundwater inflow rates of each section measured by datalogger. The calcuated inflow rates of the sections by bottle and eye measurement were 8.8%∼54.7% of inflow rate (averaging 27,4%), whwewas those by the current meter were 76.9%∼110.6%(averaging 92.9%). Therfore, the current meter is regarded as useful method to calculate groundwater inflow rates into subsections of a tunnel.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.719-724
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• 2002

In the paper, we describe the IPv6-based multicast videoconferencing tool and it's experimental results by using TEM (TransEurasia Information Network) which is connected between Korea and Europe recently. And we explain the efficient configuration method of IPv6 multicast as well as IPv6 configured tunneling in between Korea and Europe.

• Tunnel and Underground Space
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• v.21 no.5
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• pp.333-340
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• 2011

RMR is most strongly adopted rock classification method to scheme support system in domestic tunnel. However the RMR, which is based on geological survey during design stage of tunnel, can't present the real ground accurately. In this study, authors suggested Weighted-RMR (W-RMR) which is considered weighted value of risk factors of collapse due to prevent collapse and roof falls during tunneling. According to the application of W-RMR to Bye-Gye tunnel, we could change support type flexibly by the risk factors on a face of tunnel.