• 제목/요약/키워드: Protection Mechanism

검색결과 712건 처리시간 0.028초

이온 플레이팅법에 의한 내식 박막의 제작과 부식방식 메카니즘 (Preparation of corrosion-resistive thin films by ion plating method and their corrosion protection mechanism)

  • 이경희;배일용;김기준;문경만;이명훈
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.285-286
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    • 2006
  • Magnesium is the lightest of all the structural metals having density of 1.74. It is approximately 2/3 lighter than aluminium, l/4 lighter than titanium alloy and 1/5 lighter than iron. Among the light-weight alloys, magnesium and its alloys show a good possibility for high performance aerospace and automotive applications, however the widespread use of magnesium alloys has been limited mainly by its poor oxidation and corrosion resistance. In this work, corrosion-resistive thin films were prepared onto the magnesium alloy substrate(AZ91D) by environmental friendly coating technique, ion plating method. And their corrosion protection mechanism were analyzed.

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A Cache Privacy Protection Mechanism based on Dynamic Address Mapping in Named Data Networking

  • Zhu, Yi;Kang, Haohao;Huang, Ruhui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권12호
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    • pp.6123-6138
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    • 2018
  • Named data networking (NDN) is a new network architecture designed for next generation Internet. Router-side content caching is one of the key features in NDN, which can reduce redundant transmission, accelerate content distribution and alleviate congestion. However, several security problems are introduced as well. One important security risk is cache privacy leakage. By measuring the content retrieve time, adversary can infer its neighbor users' hobby for privacy content. Focusing on this problem, we propose a cache privacy protection mechanism (named as CPPM-DAM) to identify legitimate user and adversary using Bloom filter. An optimization for storage cost is further provided to make this mechanism more practical. The simulation results of ndnSIM show that CPPM-DAM can effectively protect cache privacy.

CR-LDP 우회를 통한 GMPLS LSP의 보호 및 복구 (Protection and Restoration of GMPLS LSP using CR-LDP Detours)

  • 김진형;정재일
    • 한국통신학회논문지
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    • 제28권12B호
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    • pp.1051-1059
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    • 2003
  • GMPLS는 신호 및 라우팅 기술을 기반으로 트래픽의 요구가 있을 때 동적으로 네트워크에서 경로를 설정하고 자원을 할당하는 기술이다. 또한 많은 양의 트래픽을 처리하는 특성상 네트워크의 실패(failure)가 일어났을 때 동적으로 트래픽을 보호하는 경로 보호 및 복구 메커니즘을 포함한다. 본 논문에서는 GMPLS의 신호 프로토콜 기술인 CR-LDP의 오브젝트를 확장하여 매 노드에서 자동적으로 우회 경로를 설정하여 주 경로를 보호 및 복구하기 위한 정적 우회 기법 및 동적 우회 기법을 제안하고 기존의 경로 보호 및 복구 기법과 성능을 비교 평가한다.

팔라디움-은합금에 의한 도재의 색조변화 및 변색작용에 관한 연구 (A STUDY ON THE COLOR CHANCE OF CERAMIC BY Pd-Ag ALLOY AND MECHANISM)

  • 윤수선;이선형;양재호;정헌영
    • 대한치과보철학회지
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    • 제27권1호
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    • pp.123-141
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    • 1989
  • The purpose of this study was to investigate the tendency of color change of ceramic, and its mechanism un der the influence of Pd-Ag alloy. The specimens were made by firing porcelain on tile metal plates cast with Au-Pt alloy, Pd-Cu alloy and Pd-Ag alloy. In the case of Pd-Ag alloy, specimens were fired under three different conditions as follows, 1) without protection, 2) protection with ceramic metal conditioner, 3) protection with carbon block. For the specimens of element analysis, a barrier was constructed with platinum foil between metal plate and ceramic. Color change was measured with colorimeter and elemental changes in ceramic were calculated with DC argon plasma emission spectrophotometer. The results were as follows : 1. Color change of ceramic by Pd-Ag alloy was negligible in hue, but decreased in value and increased in chroma (yellow discoloration). 2. Color change of ceramic by Pd-Ag alloy was appeared through vapor transport mechanism. 3. As the protection method for the color change of ceramic by Pd-Ag alloy, application of ceramic metal conditioner was superior to utilization of carbon block.

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RFID-based Secure Communication for Smart Device in Future Home Network Environment

  • Li, Nong-Jun;Choi, Kee-Hyun;Jang, Kyung-Soo;Shin, Dong-Ryeol
    • International Journal of Internet, Broadcasting and Communication
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    • 제5권1호
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    • pp.18-22
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    • 2013
  • We introduce, in this paper, a novel approach of protection mechanism for data which are transmitted not only between the networked devices but also between the digital media devices. As the devices are getting more powerful and more storage capacity, they can process the encoded/encrypted data autonomously. However, all devices must know the secret key that used to encrypt data, and also use secure method to distribute that key. Moreover, there are no protection mechanisms supporting end-to-end copy protection which result in the fact that the data passed through various devices can be manipulated or captured. Therefore, we propose a RFID-based key distribution and protection mechanism to resolve these problems.

Magni 565 코팅 볼트의 내식성 및 토오크 특성에 대한 연구 (A Study of Corrosion Resistance and Torque in Bolt Coated with Magni 565)

  • 김상수;김무길;정병호
    • 열처리공학회지
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    • 제20권4호
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    • pp.195-202
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    • 2007
  • Corrosion resistance and torque of M10 bolt coated with Magni 565 were investigated. Corrosion protection mechanism were also studied with the microstructure of coating film. The bolts with the optimum conditions showed around $10{\mu}m$ layer thickness, a great corrosion resistance in salt spray test and a proper torque in torque/tension test. But torque coefficient k increased with the number of bolting and clamping force of M10 bolt showed significantly lower than that of specified value 28.3kN. It was thought that the repeated bolting made the coating film peel off and powdery. The sample coated with optimum coating conditions showed more higher polarization resistance and corrosion potential than the specimens of top and base coat only. The base coating film was composed of lamellar zinc flakes, which provides a large sacrificial cathodic protection. Meanwhile, the top coating film was composed of organic aluminium pigments layer, which provides barrier protection to the corrosion circumstances.

Some aspects of scintillation mechanism in organic molecular dielectrics

  • Galunov, N.Z.;Grinev, B.V.;Tarasenko, O.A.;Martynenko, E.V.
    • Journal of Radiation Protection and Research
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    • 제30권2호
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    • pp.85-89
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    • 2005
  • Aspects of the scintillation mechanism in organic systems obtained on the base of precise measurements of the radioluminescence pulse shape are discussed. It shown that the process of scintillation light pulse formation is mainly determined by initial conditions of exited states generation.

열동형 과부하 계전기의 메커니즘 해석 (Mechanism Analysis of Thermal Overload Relay)

  • 이경구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 A
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    • pp.287-289
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    • 1999
  • This paper proposes mechanism analysis in thermal overload relay. Overload protection performance is closely connected with mechanism of thermal overload relay. In shortage of analytical technique, we have experienced many difficulties in development of thermal overload relay. We applied analytical results to develop optimum thermal overload relay.

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Characterization of the brittleness of hard rock at different temperatures using uniaxial compression tests

  • Chen, Guoqing;Li, Tianbin;Wang, Wei;Guo, Fan;Yin, Hongyu
    • Geomechanics and Engineering
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    • 제13권1호
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    • pp.63-77
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    • 2017
  • The failure mechanism of a deep hard rock tunnel under high geostress and high geothermalactivity is extremely complex. Uniaxial compression tests of granite at different temperatures were conducted. The complete stress-strain curves, mechanical parameters and macroscopic failure types of the rock were analyzed in detail. The brittleness index, which represents the possibility of a severe brittleness hazard, is proposed in this paperby comparing the peak stress and the expansion stress. The results show that the temperature range from 20 to $60^{\circ}C$ is able to aggravate the brittle failure of hard rock based on the brittleness index. The closure of internal micro cracks by thermal stress can improve the strength of hard rock and the storage capacity of elastic strain energy. The failure mode ofthe samples changes from shear failure to tensile failure as the temperature increases. In conclusion, the brittle failure mechanism of hard rock under the action of thermal coupling is revealed, and the analysis result offers significant guidance for deep buried tunnels at high temperatures and under high geostress.