• Journal of the Korean Magnetics Society
• /
• v.26 no.1
• /
• pp.7-12
• /
• 2016

Effects of annealing of the gas-atomized Fe-9%Si-2%Cr powder which is suitable for high frequency application in mobile devices because of its high electrical resistivity were studied with an emphasis on the order-disorder phase transition. The formation of B2 ordered phase could not be suppressed during atomization process. When the powder was annealed at a temperature higher than $550^{\circ}C$ the peak diffracted from $DO_3$ phase could be detected. With increasing annealing temperature lattice parameter and coercivity decreased. An interesting phenomenon was an abrupt increment of coercivity in the powder annealed at $450^{\circ}C$. Highest permeability could be shown in the powder annealed at a relative low temperature of $150^{\circ}C$ and then the permeability decreased with annealing temperature. The above-mentioned results could be successfully explained by both the formation of $DO_3$ ordered phases and the change of electrical resistivity of the Fe-Si-Cr powder which was also originated from the phase transition.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.10c
• /
• pp.155-158
• /
• 2007

현재 전자상거래는 우리의 생활과 밀접히 연관되어 있다. 최근 인터넷을 기반으로 전자조달, 수출입 브로커 등과 같은 유형의 B2B 전자상거래가 활발히 이루어지고 있으며, 소비자를 대상으로 하는 전자상거래 또한 점차 확산되는 시장을 형성하고 있다. 국제적으로도 전자상거래 시장 규모가 급속도로 증가할 것이라는 전망은 자명한 사실이다. 전자상거래에 대한 의존도가 높아지면서 관리해야 하는 데이터의 양 또한 급속도로 증가하고 있다. 본 논문에서는 실시간으로 유입되는 데이터를 효율적으로 활용하기 위챈 실시간 데이터 마이닝 활용 모델을 제안한다. 이 실시간 데이터 마이닝 모델은 지속적으로 유입되는 데이터의 규칙화를 통해 저장 공간의 효율성을 극대화하고 중요도 분석을 통한 총체적인 접근 방법을 시도함으로써 전자상거래 상에서 유용하게 쓰일 수 있는 활용 모델이다. 이 실시간 데이터 마이닝 모델의 바탕은 데이터 마이닝의 기법인 SEMMA를 따르며, 그 특징에 따라 규칙 추출과 의사 결정 나무 기법을 이용하여 전자상거래 상에서 유용하게 사용될 수 있는 모델을 제시하고자 한다.

• Journal of Technologic Dentistry
• /
• v.20 no.1
• /
• pp.37-49
• /
• 1998

The specimens used were Ag-25 Pd-15 Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age- hardening characteristics of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing. X-ray diffraction and electron microscope observations, electrical resistance, ergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, i.e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the $L1_0$ type face-centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affected by the Cu concentration. In stage II, decomposition of the ${\alpha}$ solid solution to a PdCu ordered phase($L1_0$ type) and an Ag-rich ${\alpha}2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was conclued that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipetation procedure was ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu {\to}{\alpha}_1+{\alpha}_2+PdCu$ at Pd/Cu = 1.7 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Journal of the Korean Society for Heat Treatment
• /
• v.9 no.2
• /
• pp.79-90
• /
• 1996

Transmission electron microscopy(TEM) investigation on the phase decomposition of B2-ordered (Ni,Co)Al supersaturated with Ni and Co has revealed the precipitation of $(Ni,Co)_2Al$ which has not been expected from the reported equilibrium phase diagram. The $(Ni,Co)_2Al$ phase has a hexagonal struture and takes a rod-like shape with the long axis of the rod parallel to the <111> directions of the B2 matrix. By aging at temperatures below 873 K, a long period Superlattice Structure appears in the hexagonal $(Ni,Co)_2Al$ Phase. The orientation relationship between the $(Ni,Co)_2Al$ Precipitates and the B2-(Ni,Co)Al matrix is found to be$(0001)_p$ // $(111)_{B2}$ and $[\bar{1}2\bar{1}0]_P$ // $[\bar{1}10]_{B2}$, Where the suffix p and B2 denote the $(Ni,Co)_2Al$ precipitate and the B2-(Ni,Co)Al matrix, respectively. (Ni,Co)Al hardens appreciably by the fine precipitation of the $(Ni,Co)_2Al$ phase. Energy dispersive spectroscopy was used to analyze the compositions of each phase formed in B2-(Ni,Co)Al.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.2B
• /
• pp.91-97
• /
• 2006

As increasing the network bandwidth, the threat of a network also increases with emerging various new services. For a high-performance network security, It is generally used that high-speed packet classification methods which employ hardware like TCAM. There needs an method using these devices efficiently because they are expensive and their capacity is not sufficient. In this paper, we propose an efficient packet classification using a Ternary-CAM(TCAM) which is widely used device for high-speed packet classification in which we have applied Snort rule set for the well-known intrusion detection system. In order to save the size of an expensive TCAM, we have eliminated duplicated IP addresses and port numbers in the rule according to the partitioning of a table in the TCAM, and we have represented negation and range rules with reduced TCAM size. We also keep advantages of low TCAM capacity consumption and reduce the number of TCAM lookups by decreasing the TCAM partitioning using combining port numbers. According to simulation results on our TCAM partitioning, the size of a TCAM can be reduced by upto 98$\%$ and the performance does not degrade significantly for high-speed packet classification with a large amount of rules.

• The Korean Journal of Rheology
• /
• v.9 no.4
• /
• pp.200-205
• /
• 1997

등방상에서는 폴리파라페닐렌테레프탈아미드(PPD-T)와 히드록시 프로필 셀룰로오 스(HPC)가 비슷한 유변학적 거동을 보였다. 그러나 이방성에서는 네마틱상을 형성하는 PPD-T와 콜레스테릭상(또는 꼬인 네마틱상)을 형성하는 HPC는 상이한 유변학적 특성을 나타냈다. 이방상을 나타내는 임계농도(C*)이상의 농도에서 Herchel-Bulkey 모델에 의해 얻 어진 항복응력을 보면 HPC의 경우 농도에 관계없이 거의 일정한 값을 나타낸 반면PPD-T 의경우에는 농도증가와 더불어 항북응력값이 크게 증가하였다. 또한 PPD-T가 일\ulcorner거으로 HPC보다 큰값의 항복응력을 나타냈다. 진동수 1 rad/s 에서는 PPD-T와 HPCahen 탄성계 수 G＇/2G＂가 농도의 증가와 더불어 증가하엿다. 그러나 100rad/s 에서는 HPCdmlruddn 임계농도이상의 농도에서 농도증가와 더불어 탄성계수값이 단순감소한 반면 PPD-T의 경우 에는 포화농도(B-point)이상의 농도에서 농도증가와 더불어 탄성계수값이 계속적으로 증가 하였다. HPC의 경우 저장탄성률이 변형정도의 영향을 받지 않았으나 PPD-T의 경우에는 저장탄성률이 변형정도에 매우 민감하였다.

• Journal of the Korean Society for Heat Treatment
• /
• v.20 no.4
• /
• pp.187-194
• /
• 2007

A transmission electron microscope (TEM) investigation has been performed on the precipitation of $L2_1$-type $Ni_2AlTi$ phase in B2-ordered NiAl system. The hardness after solution treatment is high in NiAl-Ti alloys suggesting the large contribution of solid solution strengthening in this alloy system. However, the amount of age hardening is not large as compared to the large microstructural variations during aging. At the beginning of aging, the $L2_1$-type $Ni_2AlTi$ precipitates keep a lattice coherency with the NiAl matrix. By longer periods of aging $Ni_2AlTi$ precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. Misfit dislocations, which are observed on {100} planes of H-precipitates have the Burgers vector of a <100> with a pure edge type. The lattice misfits of NiAl-$Ni_2AlTi$ system is estimated from the spacings of misfit dislocations to be 1.1% at 1273 K. The lattice misfits decrease with increasing aging temperature in this system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.236-242
• /
• 2019

Recently, scanning projects have been carried out in various construction and construction fields for maintenance purposes. The point cloud generated by the scan results is composed of a number of points representing the object to be scanned. The process of extracting the necessary information, including dimensions, from such scan data is called paradox. The reverse engineering process of modeling a point cloud as BIM involves considerable manual work. Owing to the time-consuming reverse engineering nature of the work, the costs increase exponentially when rework requests are made, such as design changes. Reverse engineering automation technology can help improve these problems. On the other hand, the reverse design product is variable depending on the use, and the kind and detail level of the product may be different. This paper proposes the G2BM (Geometry-to-BIM mapping) rule definition method that automatically maps a BIM object from a primitive geometry to a BIM object. G2BM proposes a process definition and a customization method for reverse engineering BIM objects that consider the use case variability.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11c
• /
• pp.1749-1752
• /
• 2002

최근 들어 B2B 기반의 전자상거래 프레임워크로 UN/CEFACT 과 OASIS 를 주축으로 하는 ebXML과 Microsoft, IBM, Ariba를 포함한 기업과 단체를 주축으로 하는 웹 서비스가 대두되고 있다. 이들은 모두 사용자 및 어플리케이션들이 정보를 저장하고 이를 공유할 수 있는 Registry 를 기반으로 서비스를 제공하고 있으며, 이를 위해 ebXML 은 ebXML Registry를, 웹 서비스는 UDDI Registry를 이용한다. ebXML 과 웹 서비스는 서로 다른 Registry 를 사용하고 있지만, Registry 를 사용하고 있지만, Registry 의 구조와 기능은 유사하거나 동일한 부분이 많다. 본 논문은 이에 착안하여 서로 유사하거나 동일한 역할을 가진 ebXML RIM의 구조와 UDDI의 데이터구조를 매핑함으로써, ebXML RIM 상에 UDDI 데이터구조를 표현하는 규칙을 찾고, 이를 이용하여 UDDI Registry Client의 서비스 요구를 ebXML Registry 를 이용하여 처리하는 UDDI Registry Server 를 설계한다. 이는 ebXML Registry 에 별도의 변경을 가하지 않고도 UDDI Registry Client 가 ebXML Registry 를 사용할 수 있게 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.639-643
• /
• 2004

[ $Ta_2O_5$ ]가 첨가된 $Ba(Zn_{1/3}Ta_{2/3})O_3$[BZT] 세라믹은 1:2 규칙화 정도가 증가하고 $Ba_3Ta_5O_{15}의 이차상이 새롭게 형성된다. $1580^{\circ}C$ 보다 높은 온도에서 소결된 BZT 세라믹은 $Ta_2O_5$를 첨가하면 입자의 성장이 일어나고 액상이 형성된다. 품질계수(Q) 값은 $1580^{\circ}C$ 보다 높은 온도에서 소결할 경우 미량의 $Ta_2O_5$ 첨가만으로도 상당히 증가한다. 상대밀도는 $Ta_2O_5$ 첨가량에 따라 감소하기 때문에 Q값의 증가는 상대밀도와는 무관하다. 반면에, $Ta_2O_5$의 첨가량에 따라 입자의 성장은 증가하였기 때문에 Q값의 향상은 입자크기와 관계가 있음을 알 수 있다. 많은 양의 $Ta_2O_5$ 첨가시 비록 입자 크기가 증가했음에도 불구하고 Q값이 매우 낮은 것을 볼 때, Q값의 감소는 $Ba_3Ta_5O_{15}$ 상의 영향과 낮은 밀도 값에 기인한 것이다.