• 제목/요약/키워드: physical protection

검색결과 699건 처리시간 0.028초

Surface Protection Obtained by Anodic Oxidation of New Ti-Ta-Zr Alloy

  • Vasilescu, C.;Drob, S.I.;Calderon Moreno, J.M.;Drob, P.;Popa, M.;Vasilescu, E.
    • Corrosion Science and Technology
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    • 제17권2호
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    • pp.45-53
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    • 2018
  • A new 80Ti-15Ta-5Zr wt% alloy surface was protected by anodic oxidation in phosphoric acid solution. The protective oxide layer (TiO2, ZrO2 and Ta suboxides and thickness of 15.5 nm) incorporated $PO{_4}^{3-}$ ions from the solution, according to high resolution XPS spectra. The AFM analysis determined a high roughness with SEM detected pores (20 - 50 nm). The electrochemical studies of bare and anodically oxidized Ti-15Ta-5Zr alloy in Carter-Brugirard saliva of different pH values and saliva with 0.05M NaF, pointed to a nobler surface for the protected alloy, with a thicker electrodeposited oxide layer acting as a barrier against aggressive ions. The oxidized alloy significantly decreased corrosion current densities and total quantity of ions released into the oral environment in comparison with the bare one, at higher polarisation resistance and protective capacity of the electrodeposited layer. The impedance data revealed a bi-layered oxidation film formed by: a dense, compact, barrier layer in contact with the metallic substrate, decreasing the potential gradient across the metal/oxide layer/solution interface, reducing the anodic dissolution and a more permissive, porous layer in contact with the electrolyte. The open circuit potential for protected alloy shifted to nobler values, with thickening of the oxidation film signifying long-term protection.

20세기 중반 이후 후드 복식에 나타난 복식미 (The Aesthetics of Hooded Garments after the Mid-20th Century)

  • 최선영;김민자
    • 복식
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    • 제62권3호
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    • pp.1-16
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    • 2012
  • The purpose of this dissertation is to examine the various types of hooded garments that have been worn after the $20^{th}$ century, and to analyze the aesthetic values of them. The study examined various types of hooded garments with diverse significances based on literature and case studies on the history of garments, news paper articles and the Internet. Since the $20^{th}$ century, there has been a variety of hooded garments, such as monk dresses, hoodies, anoraks, duffle coats, some protective clothing, and designers' hooded clothes. Through this research, the study found that the aesthetics of hooded garments after the mid-20th century were as follows: physical protection, anonymity, psychological refuge, fashionability and high-functionality.

Inelastic two-degree-of-freedom model for roof frame under airblast loading

  • Park, Jong Yil;Krauthammer, Theodor
    • Structural Engineering and Mechanics
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    • 제32권2호
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    • pp.321-335
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    • 2009
  • When a roof frame is subjected to the airblast loading, the conventional way to analyze the damage of the frame or design the frame is to use single degree of freedom (SDOF) model. Although a roof frame consists of beams and girders, a typical SDOF analysis can be conducted only separately for each component. Thus, the rigid body motion of beams by deflections of supporting girders can not be easily considered. Neglecting the beam-girder interaction in the SDOF analysis may cause serious inaccuracies in the response values in both Pressure-Impulse curve (P-I) and Charge Weight-Standoff Diagrams (CWSD). In this paper, an inelastic two degrees of freedom (TDOF) model is developed, based on force equilibrium equations, to consider beam-girder interaction, and to assess if the modified SDOF analysis can be a reasonable design approach.

차세대 사이버 보안 동향 (The Trends of Next Generation Cyber Security)

  • Lee, Daesung
    • 한국정보통신학회논문지
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    • 제23권11호
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    • pp.1478-1481
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    • 2019
  • As core technologies(IoT, 5G, Cloud, Bigdata, AI etc) leading the Fourth Industrial Revolution promote smart convergence across the national socio-economic infrastructure, the threat of new forms of cyber attacks is increasing and the possibility of massive damage is also increasing. Reflecting this trend, cyber security is expanding from simple information protection to CPS(Cyber Physical System) protection that combines safety and security that implements hyper-connectivity and ultra-reliability. This study introduces the recent evolution of cyber attacks and looks at the next generation cyber security technologies based on the conceptual changes of cyber security technologies such as SOAR(Security Orchestration, Automation and Response) and Zero Trust.

Protection Management for Guaranteed User-Driven Virtual Circuit Services in Dynamic Multi-domain Environments: Design Issues and Challenges

  • Lim, Huhnkuk
    • ETRI Journal
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    • 제37권2호
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    • pp.369-379
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    • 2015
  • Fault management of virtualized network environments using user-driven network provisioning systems (NPSs) is crucial for guaranteeing seamless virtual network services irrespective of physical infrastructure impairment. The network service interface (NSI) of the Open Grid Forum reflects the need for a common standard management API for the reservation and provisioning of user-driven virtual circuits (VCs) across global networks. NSI-based NPSs (that is, network service agents) can be used to compose user-driven VCs for mission-critical applications in a dynamic multi-domain. In this article, we first attempt to outline the design issues and challenges faced when attempting to provide mission-critical applications using dynamic VCs with a protection that is both user-driven and trustworthy in a dynamic multi-domain environment, to motivate work in this area of research. We also survey representative works that address inter-domain VC protection and qualitatively evaluate them and current NSI against the issues and challenges.

NSA IDS System PP와 국가기관용 IDS PP 가정사항 비교분석 (Comparison & Analysis of Intrusion Detection System System Protection Profile of NSA and MIC)

  • 김남기;박종오;김지영
    • 융합보안논문지
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    • 제3권2호
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    • pp.57-65
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    • 2003
  • 보호프로파일은(Protection Profile)은 특정형태의 제품군이 지녀야 할 보안 목적을 사용자 그룹에서 요구한 명세서이며 보호프로파일의 가정사항은 TOE(Target Of Evaluation)의 물리적, 인적, 네트워크적 관점을 포함하는 사용 환경과 TOE의 사용제한, 잠재적인 자산 가치, 추가적인 적용의 관점을 포함하는 TOE 사용 방법상의 내용을 기술한 것이다. 본 논문에서는 NSA(National Security Agency) 침입탐지 시스템 보호프로파일과 국가기관용 침입탐지 시스템 보호프로파일의 가정사항 항목을 비교 분석하였다.

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Routing and Wavelength Assignment in Survivable WDM Networks without Wavelength Conversion

  • Lee, Tae-Han;Park, Sung-Soo;Lee, Kyung-Sik
    • Management Science and Financial Engineering
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    • 제11권2호
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    • pp.85-103
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    • 2005
  • In this paper, we consider the routing and wavelength assignment problem in survivable WDM transport network without wavelength conversion. We assume the single-link failure and a path protection scheme in optical layer. When a physical network and a set of working paths are given, the problem is to select a link-disjoint protection path for each working path and assign a wavelength for each working and protection path. We give an integer programming formulation of the problem and propose an algorithm to solve it. Though the formulation has exponentially many variables, we solve the linear programming relaxation of it by using column generation technique. We devise a branch-and price algorithm to solve the column generation problem. After solving the linear programming relaxation, we apply a variable fixing procedure combined with the column generation to get an integral solution. We test the proposed algorithm on some randomly generated data and test results show that the algorithm gives very good solutions.

원자력발전소 화재방호와 소방시설 기술기준 적용에 대한 고찰 (A Study on Fire Protection in Nuclear Power Plants and Application of the Code and Standards for Fire Protection Systems)

  • 김위경;정기신
    • 한국화재소방학회논문지
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    • 제26권6호
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    • pp.38-44
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    • 2012
  • 원자력발전소 화재방호의 목표는 화재 시 원자로의 안전정지 상태를 유지하여 환경으로의 방사성물질 누출을 최소화하며, 종사자 인명안전 및 재산을 보호하는데 있다. 소방시설은 발생된 화재를 조기 감지 및 진압하여 화재로 인한 피해를 완화시킬 수 있는 심층방어개념에 입각한 중요한 방어수단의 하나이다. 그러나 소방방재청에서 제시하고 있는 소방시설 설치기준이 원자력발전소에 특화되어 있지 않아 인허가 시 별도의 심의 절차가 요구되고 있다. 또한, 성능위주설계와 같은 규정은 작업자의 인구밀도가 비교적 낮은 원자력발전소에 적용하는데 어려움이 있다. 이 논문에서는 원전 화재방호와 관련된 법령의 상세 검토를 통하여 도출된 근본적인 문제점과 KEPIC FPN의 국내 원전 적용성에 대한 평가를 통하여 소방시설에 대한 기술기준에 대한 개선방향을 제시하였다.