• 한국통신학회논문지
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• 제22권5호
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• pp.1064-1074
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• 1997

본 논문에서는 WDM 멀티흡 통신망을 효과적으로 구현하기 위한 새로운 논리적 토폴로지인 하나 걸른 행과 연결된 이중층 셔플넷 토폴로지를 제안한다. 제안한 토폴로지의 최대 흡수와 평균 흡수를 이용하여 수율(througyput)과 시간 지연을 계산하고, 제안한 토폴로지가 수율(througyput)과 시간 지연의 측면에 있어서 이전에 발표된 셔플넷 토폴로지, 이중층 셔플넷 토폴로지 그리고 비대칭 이중층 셔플넷들에 비해 성능이 개선됨을 보인다.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.281-286
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• 2002

In odder to investigate the magnetic properties of CoCr-based bilayered thin films on kind of underlayer, we introduced amorphous Si layer to Co-Cr(-Ta) magnetic layer as underlayer. First, we prepared CoCr and CoCrTa single layer using the Facing Targets Sputtering system to investigate theirs properties. It was revealed that with increasing the film thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. The CoCrTa thin film showed bettor crystalline and magnetic characteristics than CoCr thin film. As a result of investigating magnetic properties of CoCr and CoCrTa magnetic layer on introducing the Si underlayer, perpendicular coercivity and saturation magnetization of CoCr/Si and CoCrTa/Si bilayered thin film were decreased due to the increased grain size and diffusion of Si atoms to magnetic layer. And they showed constant with increasing the film thickness of Si thin film. However, in case of CoCrTa/Si bilayered thin film, in-plane coercivity was controlled low at about 250Oe. The c-axis orientations of CoCr/si and CoCrTa/Si bilayered thin film showed a good crystalline characteristics as about $2^{\circ}$.

• 대한전자공학회논문지SD
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• 제41권5호
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• pp.1-7
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• 2004

규칙적인 논리적 연결방법을 이용하면 노드에서 라우팅을 위한 프로세싱 시간이 단축되므로 고속의 네트워크에 적용이 가능하다. 규칙적인 논리적 연결방법의 하나인 셔플넷은 일반적으로 p개의 직접 연결이 다른 노드들과 이루어진다. 그러나 우리가 제안한 비대칭 이중층 셔플넷 토폴로지를 이용하면 2p개의 노드들과 직접 연결되므로 더욱 용량이 증대된 파장분할방식 링을 설계할 수 있다. 이 비대칭 이중층 셔플넷 토폴로지를 이용하여 파장분할방식 링에 파장을 할당하는 방법을 본 논문에서 연구하였다. 필요한 파장수를 최소화하는 것을 목표로 네트워크를 최적화하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.100-103
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• 2001

In order to investigate the magnetic properties of CoCr-based bilayered thin films on kind of underlayer, we introduced amorphous Si layer to Co-Cr(-Ta) magnetic layer as underlayer. With the thickness of CoCr, CoCrTa single layer, crystalline orientation and perpendicular coercivity was improved. It was revealed that by introducing the Si underlayer, the c-axis orientation of CoCr, CoCrTa magnetic layer was improved largely. However, with increasing Si film thickness, perpendicular coercivity and saturation magnetization of Cocr/si, CoCrTa/Si bilayered thin films was decreased. Grain size of bilayered thin films became larger.

• 대한전자공학회논문지SD
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• 제39권6호
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• pp.19-25
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• 2002

규칙적인 가상 연결방법을 이용하면 노드에서 라우팅을 위한 프로세싱 시간이 단축되어 고속의 네트워크에 적용이 가능하다. 규칙적인 가상 연결방법의 하나인 셔플넷은 일반적으로 p개의 연결이 다른 노드들과 이루어진다. 그러나 우리가 제안한 하나 걸른 행과 연결된 이중층 셔플넷 토폴로지를 이용하면 2p개의 노드들과 동시에 연결되므로 더욱 효과적인 광역 통신망에 적용할 수 있다. 이 하나 걸른 행과 연결된 이중층 셔플넷 토폴로지를 이용하여 물리적 토폴로지에 가상 토폴로지를 imbedding하는 방법을 본 논문에서 연구하였다. 전체 지연 시간을 최소화하는 것을 목표로 네트워크를 최적화하였다.

• 대한금속재료학회지
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• 제49권6호
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• pp.498-504
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• 2011

We examined the microstructure and optical properties of crystallized ~30 nm-ZnO/~10 nm amorphous $TiO_2$ nano bilayered films as nano electrodes were deposited at extremely low substrate temperatures of $150-210^{\circ}C$. The bilayered films were deposited on silicon substrates with 10 cm diameters by ALD (atomic layer deposition) using DEZn (diethyl zinc(Zn(C2H5)2)) and TDMAT (tetrakis dimethyl-amid $titanium(Ti(N(CH_3)_2)_4)$ as the ZnO and $TiO_2$ precursors, respectively, and $H_2O$ as the oxidant. The microstructure, phase, and optical properties of the bilayered films were examined by FE-SEM, TEM, XRD, AES, and UV-VIS-NIR spectroscopy. FE-SEM and TEM showed that all bilayered films were deposited very uniformly and showed crystallized ZnO and amorphous $TiO_2$ layers. AES depth profiling showed that the ZnO and $TiO_2$ films had a stoichiometric composition of 1:1 and 1:2, respectively. These bilayered films have optical absorption properties in a wide range of ultraviolet wavelengths, 250-390 nm, whereas the single ZnO and $TiO_2$ films showed an absorption range of 350-380nm.

• 대한전자공학회논문지SD
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• 제39권5호
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• pp.41-45
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• 2002

비대칭 이중층 셔플넷 토폴로지를 멀티홉 WDM cross-connect 구현을 위하여 적용하였다. 그 결과로 필요한 WDM cross connect 수가 기존의 셔플넷 토폴로지 적용에 비하여 반으로 감소하며 이로 인하여 평균 흡수가 감소하고 평균 지연 시간을 줄일 수 있다.

• 한국세라믹학회지
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• 제55권5호
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• pp.452-460
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• 2018

This study investigate changes in mechanical behaviors such as indentation load-displacement and hardness of thermal barrier coatings (TBCs) using cycling of thermal shock test. Relatively dense and porous TBCs on nickel-based bondcoat/super alloy are prepared using different starting granules, 204C-NS and 204NS commercial powers, and the effect of double layers of 204C-NS on 204NS and 204NS on 204C-NS are investigated. The highest temperature applied during thermal shock test is $1100^{\circ}C$ and the maximum number of cycles is 1,200. The results indicate that bilayered TBC showed a relatively mechanically resistant property during thermal shock cycles and that the mechanical behavior is influenced by the microstructure of TBCs by exposure to high temperature during tests or different starting granules.

• The Journal of Advanced Prosthodontics
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• 제7권5호
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• pp.358-367
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• 2015

PURPOSE. The aim of this study was to evaluate the biaxial flexural strength (BFS) of one zirconia-based ceramic used with various veneering ceramics. MATERIALS AND METHODS. Zirconia core material (Katana) and five veneering ceramics (Cerabien ZR; CZR, Lava Ceram; LV, Cercon Ceram Kiss; CC, IPS e.max Ceram; EM and VITA VM9; VT) were selected. Using the powder/liquid layering technique, bilayered disk specimens (diameter: 12.50 mm, thickness: 1.50 mm) were prepared to follow ISO standard 6872:2008 into five groups according to veneering ceramics as follows; Katana zirconia veneering with CZR (K/CZR), Katana zirconia veneering with LV (K/LV), Katana zirconia veneering with CC (K/CC), Katana zirconia veneering with EM (K/EM) and Katana zirconia veneering with VT (K/VT). After 20,000 thermocycling, load tests were conducted using a universal testing machine (Instron). The BFS were calculated and analyzed with one-way ANOVA and Tukey HSD (${\alpha}$=0.05). The Weibull analysis was performed for reliability of strength. The mode of fracture and fractured surface were observed by SEM. RESULTS. It showed that K/CC had significantly the highest BFS, followed by K/LV. BFS of K/CZR, K/EM and K/VT were not significantly different from each other, but were significantly lower than the other two groups. Weibull distribution reported the same trend of reliability as the BFS results. CONCLUSION. From the result of this study, the BFS of the bilayered zirconia/veneer composite did not only depend on the Young's modulus value of the materials. Further studies regarding interfacial strength and sintering factors are necessary to achieve the optimal strength.

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.151-156
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• 2014

PURPOSE. To investigate the microtensile bond strength between two all-ceramic systems; lithium disilicate glass ceramic and zirconia core ceramics bonded with their corresponding glass veneers. MATERIALS AND METHODS. Blocks of core ceramics (IPS e.max$^{(R)}$ Press and Lava$^{TM}$ Frame) were fabricated and veneered with their corresponding glass veneers. The bilayered blocks were cut into microbars; 8 mm in length and $1mm^2$ in cross-sectional area (n = 30/group). Additionally, monolithic microbars of these two veneers (IPS e.max$^{(R)}$ Ceram and LavaTM Ceram; n = 30/group) were also prepared. The obtained microbars were tested in tension until fracture, and the fracture surfaces of the microbars were examined with fluorescent black light and scanning electron microscope (SEM) to identify the mode of failure. One-way ANOVA and the Dunnett's T3 test were performed to determine significant differences of the mean microtensile bond strength at a significance level of 0.05. RESULTS. The mean microtensile bond strength of IPS e.max$^{(R)}$ Press/IPS e.max$^{(R)}$ Ceram ($43.40{\pm}5.51$ MPa) was significantly greater than that of Lava$^{TM}$ Frame/Lava$^{TM}$ Ceram ($31.71{\pm}7.03$ MPa)(P<.001). Fluorescent black light and SEM analysis showed that most of the tested microbars failed cohesively in the veneer layer. Furthermore, the bond strength of Lava$^{TM}$ Frame/Lava$^{TM}$ Ceram was comparable to the tensile strength of monolithic glass veneer of Lava$^{TM}$ Ceram, while the bond strength of bilayered IPS e.max$^{(R)}$ Press/IPS e.max$^{(R)}$ Ceram was significantly greater than tensile strength of monolithic IPS e.max$^{(R)}$ Ceram. CONCLUSION. Because fracture site occurred mostly in the glass veneer and most failures were away from the interfacial zone, microtensile bond test may not be a suitable test for bonding integrity. Fracture mechanics approach such as fracture toughness of the interface may be more appropriate to represent the bonding quality between two materials.