• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.59-59
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• 2000

Recently low resistance of bus line is required for large screen size TFT-LCD panels. As a result, lower resistance Al-alloy is currently reviewed extensively. The resistivity is required smaller than 10 $\mu$$\Omega$cm. In this paper, Al-Nd thin film were deposited on glass substrates by D.C. magnetron sputtering system under various condition. Its properties were characterized by SEM, AFM, XRD, 4-ping-probe. The optimal condition of Al-Nd was 12$0^{\circ}C$, 125W, 0.4Pa, 30sccm(Ar) and 35$0^{\circ}C$, 20min. annealing. At that condition the resistivity of Al-Nd(2wt.%) was about 4 $\mu$$\Omega$cm. The minimum contact resistance of ITO/Nd was about 110$\mu$$\Omega$cm in the condition of 30$0^{\circ}C$, Ar 30 sccm. O2.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.112-123
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• 1999

Virtual reality is becoming a powerful tool for various applications such as training, entertainment, surgery, tele-robotics etc. One potential use for virtual reality is to allow several users to interact in a single virtual environment, for example several students sitting in front of different computers connected over a network. In this paper, we present a loosely coupled architecture of haptic display in the multi-user virtual world. The method of controlling haptic devices as well as the way of configuring individual haptic display system are addressed. We will develop an experimental virtual reality system for two remote users and conclude with an experimental work for the task of a multi-player ping-pong and grasping of a common object.

• Journal of Microbiology
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• v.44 no.4
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• pp.457-460
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• 2006

A suspicious meningococcal meningitis death case was reported to the Beijing CDC. The blood specimen was analyzed via multi-PCR and MLST. 6 isolates from close contacts were analyzed via PFGE and MLST. According to the results of the above analyses, the cause of this case was identified as a serogroup A Neisseria meningitidis, which, in terms of sequence typing, belonged the ST7 group.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.4
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• pp.1140-1152
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• 2012

A novel and universal method of video image text detection is proposed. A coarse-to-fine text detection method is implemented. Firstly, the spectral clustering (SC) method is adopted to coarsely detect text regions based on the stationary wavelet transform (SWT). In order to make full use of the information, multi-parameters kernel function which combining the features similarity information and spatial adjacency information is employed in the SC method. Secondly, 28 dimension classifying features are proposed and support vector machine (SVM) is implemented to classify text regions with non-text regions. Experimental results on video images show the encouraging performance of the proposed algorithm and classifying features.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.379-384
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• 2006

이 논문에서 제안하는 Gnutella기반의 Balanced tree topology는 Unstructured P2P이므로 탐색 질의가 hash key에 제한되지 않고 동적인 네트워크 환경에도 적합하다. 또한 topology형태가 tree이므로 Gnutella의 큰 문제점인 질의 탐색 시 중복된 패킷을 제거하고, tree형태가 balanced tree이므로 일정 홉수 안에 모든 노드를 방문 할 수 있다. Balanced tree topology는 일정 홉 수 안에 모든 노드를 방문하기 때문에 Gnutella기반의 P2P가 가지는 희귀 자료에 대한 검색의 문제점 또한 해결하였다. Gnutella기반의 확장 ping과 확장 local cache를 사용하여 balanced tree topology유지 및 문제 해결에 필요한 추가 비용을 줄였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6175-6189
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• 2019

To slove the security and efficiency problem of anonymous authentication in vehicular ad-hoc network (VANET), we adopt the bilinear pairing theory to propose an identity-based batch anonymous authentication scheme for VANET. The tamper-proof device in the on-board unit and the trusted authority jointly realize the anonymity of vehicle identity and the signature of messages, which further enhances the security of this scheme, as well as reduces the overhead of trusted authority. Batch authentication can improve the efficiency of anonymous authentication for VANET. Security and efficiency analyses demonstrate that this scheme not only satisfies such security properties as anonymity, non-forgeability and non-repudiation, but also has advantage in time and space complexity. Simulation results show that this scheme can achieve good performance in real-time VANET communication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5324-5337
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• 2017

In this paper, we investigate the feasibility of interference alignment(IA) in signal space in the scenario of multiple cell and multiple user cellular networks, as the feasibility issue is closely related to the solvability of a multivariate polynomial system, we give the mathematical analysis to support the constraint condition obtained from the polynomial equations with the tools of algebraic geometry, and a new distribute IA algorithm is also provided to verify the accessibility of the constraint condition for symmetric system in this paper. Simulation results illustrate that the accessibility of the constraint condition is hold if and only if the degree of freedom(DoF) of each user can be divided by both the transmit and receive antenna numbers.

• Journal of Magnetics
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• v.18 no.2
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• pp.95-104
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• 2013

This paper presents a general analytical method for predicting the magnetic fields of different Halbach magnet arrays with or without back iron mounted on slotless permanent magnet (PM) linear machines. By using Fourier decomposition, the magnetization components of four typical Halbach magnet arrays are determined. By applying special synthetic boundary conditions on the PM surfaces, the expressions of their magnetic field distributions are derived based on the magnetic scalar potential (MSP), which are simpler than those based on the magnetic vector potential (MVP). The correctness of the method is validated by finite element analysis. The harmonics of airgap flux density waveforms of these Halbach magnet arrays with or without back iron are also compared and optimized.

• Fibers and Polymers
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• v.7 no.2
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• pp.112-116
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• 2006

Caprolactam is the most important raw material for making Nylon 6 fibers and its quality directly determines the quality of Nylon. So it is necessary to study the techniques and methods to remove the colorful impurities from caprolactam. In this paper, the decolorization of caprolactam aqueous solution by anion exchange resins was studied and the decoloring abilities of five commercial resins were investigated. The regeneration of the resins was also studied, too. This study shows that the resin AMTX202 have excellent decoloring ability in the column experiment and that the decoloring efficiency is correlated with the volume of resins packed and is slightly affected by the flow rate and regenerating times. The fact that the resins can be regenerated and reused without affecting the efficiency of decolorization will decrease the cost of the treatment and operation in the industry. The adsorption of colored compounds with anion exchange resins in the packed columns seems to be technically feasible.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.437-442
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• 2004

The optimization of a blade sweep for a transonic axial compressor rotor (NASA rotor 37) has been performed using a response surface method and a Reynolds-averaged Wavier-Stokes (RANS) flow simulation. Two shape variables of the rotor blade, which are used to define a blade sweep, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. The result shows that the adiabatic efficiency is increased to about 1 percent compared to that of the reference shape of the rotor blade. Relatively high increasement of the adiabatic efficiency is obtained between 20 and 60 percent span. In the present study, backward swept blade is more effective to increase the adiabatic efficiency In the axial compressor rotor.