• 대한조선학회지
• /
• 제54권1호
• /
• pp.34-39
• /
• 2017

• 한국분말재료학회지
• /
• 제5권4호
• /
• pp.329-333
• /
• 1998

Copper-10 wt. % tungsten alloyed powder was obtained by co-reduction of mixed tungsten-trioxide and copper oxide powders at 973 K for 7.2 Ks. In the alloy obtained by pressure-assisted sintering of this co-reduced powder, ultra fine tungsten particles (about 100nm) were dispersed uniformly in the copper matrix. At room temperature, the hardness of this alloy was Hv151 and the electrical conductivity was 85% IACS. After annealing at 1173 K for 3.6 Ks, the hardness and electrical conductivity were Hv147 and 84% IACS, respectively, and were same as before annealing. It was confirmed that the hardness and electrical conductivity of this alloy were hardly influenced by annealing condition since the microstructure of this alloy is highly stabilized.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2011년도 특별논문집
• /
• pp.17-20
• /
• 2011

The International Association of Classification Societies (IACS) had developed the Common Structural Rules (CSR) for bulk carriers as per the needs noted above. ISO and IMO GBS (Goal-Based Standards) are now being developed in this regard. This study has been prepared to verity the strength of forward cargo hold of 82,000 DWT class bulk carriers. A cargo hold/tank 3-D FE model was established to assess the structural adequacy of the primary structural members with the loading conditions. Full breadth model was established for the analysis considering asymmetric nature of structural layout and loading conditions. To summarize this result of structural assessment based on IACS CRS for bulk carrier, it is benefit to design this kind of bulk carriers and to study the strength assessment for the similar type of bulk carriers.

• 한국항해학회지
• /
• 제22권4호
• /
• pp.45-50
• /
• 1998

A recently constructed commercial ship is a complexive integrated system like a small city in which has a generator, power distributing facilities, various radio equipments and high power circuit breakers are installed. Therfore it could make a malfunction of the microprocessor in the various control units which are so important during the ocean voyage of larger ship. This paper has studied whether is properly required or not on the view of the actual electro magnetic compatibility status on the electromagnetic interference and suceptibility test requirments listed on the IACS (International Association of the Classification Society). Through these results, we are looking forward to the new suggestions of the Electro Magnetic Compatibility test in order to reduce the malfunction in the ship regarding test item, test level, and test condition.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2016년도 춘계학술발표대회
• /
• pp.259-262
• /
• 2016

최근 중요 인프라 업계에서 주로 다뤄지는 제어시스템을 표적으로 한 사이버 공격으로 Stuxnet에 이어 Havex RAT, BlackEnergy2 라고 하는 멀웨어(Malware)를 이용한 사건이 많이 증가하고 있다. 제어시스템의 새로운 공격 방법에 대한 대책으로 시스템 입구와 내부조직에 대한 대책을 강화하기 위한 필요성이 요구되어 왔지만 그러한 대책은 한정되어 있다. 본 논문에서는 보안대책에 필요한 인증 취득에 있어서 기준이 되는 국제 표준인 ISASecure(R)EDSA 인증제도에 착목했다. 인증평가는 요구요건이 중복되는 불필요한 인증평가 작업을 최소화 하는 것으로 인증 취득 시 발생되는 코스트를 절감할 수 있으며 기존의 정보 보안 관리체계(lSMS)의 인증을 취득하고 있는 기업이나 조직이면 제어시스템의 인증 기준으로 추가된 차분 요건만으로 취득이 가능 할 수 있을 것으로 상정된다. 이러한 제어시스템의 보안을 구현하기 위해 IACS(Industrial Automation and Control System)에서 표준화로 제정한 IEC62443 시리즈를 참조하여 세계각국에서 사용되는 제어시스템을 대상으로 인증(EDSA) 요구사항의 차분을 도출하는 수법을 제안하고자 한다.

• 대한수학회지
• /
• 제41권4호
• /
• pp.755-772
• /
• 2004

We show that the Fourier-Laplace series of a distribution on the sphere is uniformly Cesaro-summable to zero on a neighborhood of a point if and only if this point does not belong to the support of the distribution. Similar results on the ball and on the real projective space are also proved.

• 전기학회논문지
• /
• 제62권11호
• /
• pp.1617-1620
• /
• 2013

The widely-used measurement methods for conductivity of non-magnetic metals are van der Pauw method, Two Point Probe method and Eddy Current method. Among them a more simpler and easier method is the Eddy Current method and an instrument using the method is a Conductivity Meter which can measure a conductivity by contacting its probe on a sample surface. However, conductivity standards are essentially needed to confirm the meter's performance or to calibrate it. In this study, six kinds of the standards which are made of Cu, Al-1, Al-2, brass, Zn and SUS-316 are developed and conductivity ranges for the standards are 2.27 %IACS ~ 101.6 %IACS with measurement uncertainty of less than 0.3 %.

• 한국전기전자재료학회논문지
• /
• 제18권12호
• /
• pp.1159-1165
• /
• 2005

New conductor is developed by using high strength nonmagnetic steel(NM) wire as the core of overhead conductor This conductor is called ACNR overhead conductor(Aluminum Conductor Nonmagnetic Steel Reinforced). Formed by the combination of aluminum alloy wire and high strength nonmagnetic steel wire, it has about the same weight and diameter as conventional ACSR overhead conductor. To enhance properties beneficial in an electrical and mechanical conductor during the Process of high strength nonmagnetic steel wire, we made a large number of improvements and modifications in the working process, aluminum cladded method, and other process. ACNR overhead conductor, we successfully developed, has mechanical and electrical properties as good as or even better than conventional galvanized wire. Microstructure of raw material NM wire was austenite and then deformed martensite after drawing process. Strength at room temperature is about $180kgf/mm^2\~200kgf/mm^2$. The conductivity at 0.78 mm thickness of Aluminum cladded M wire is about $7\%$ IACS higher than $20\%$IACS of HC wire used as core of commercial ACSR overhead conductor. The corrosion resistance is about 3 times higher than that of HC wire.

• 한국분말재료학회지
• /
• 제14권5호
• /
• pp.292-297
• /
• 2007

The present study was focused on the synthesis of a $TiB_2$ dispersed copper matrix composite material by the combination of the mechanical milling and plasma activated sintering processes. The $Cu/TiB_2$ mixed powder was prepared by the combination of the mechanical milling and reduction processes using the copper oxide and titanium diboride powder as the raw material. The synthesized $Cu/TiB_2$ mixed powder was sintered by the plasma activated sintering process. The hardness and electric conductivity of the sintered bodies were measured using micro vickers hardness and four probe method, respectively. The relative density of $Cu/TiB_2$ composite material sintered at $800^{\circ}C$ showed about 98% of theoretical density. The $Cu-1vol%TiB_2$ composite material has a hardness of about 130Hv and an electric conductivity of about 85% IACS. The hardness and electric conductivity of $Cu-3vol%TiB_2$ composite material were about 140 Hv and about 45% IACS, respectively.

• International Journal of Advanced Culture Technology
• /
• 제3권1호
• /
• pp.46-51
• /
• 2015

The mechanical and electrical properties of aluminium alloy 6061 are reported in this present work. Aluminium alloys were homogenized at $550^{\circ}C$, for 5 hours and cooled in the furnace. The different thickness reductions of 60-90% on homogenized aluminium alloy plates were achieved by cryo-rolling. Later, the as rolled samples were aged by solution treatment at the temperatures of $520^{\circ}C$ for 1 hour, water quenched; subsequently aged at $160^{\circ}C$ for 8-24 hours and partial aged (not solution treatment) at $160^{\circ}C$ for 8- 24 hours. Mechanical and electrical properties of samples were investigated. The experimental result showed that the microhardness of cryo-rolled samples were increase with increasing the percentage of the thickness reduction. Moreover, the microhardness of cryo-rolled, aged by solution treatment samples were higher than those of the cryo-rolled and cryo-rolled, partial aged samples. The cryo-rolled alloys subjected to full aged at $160^{\circ}C$ for 24 hours exhibited the hardness of 125 HV and electrical conductivity values was 45.76 %IACS and the cryo-rolled alloys subjected to partial aged at $160^{\circ}C$ for 20 hours exhibited the hardness of 67 HV and electrical conductivity values was 49.67 %IACS.