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211.
A highly linear, low noise differential down-converter employing a new linearisation technique derived from composite transistors, i.e. nMOSFET and vertical NPN BJT, is proposed and implemented in a 0.18 μm CMOS technology. It draws 1 mA from a 2.5 V supply voltage and has a voltage gain of 13 dB, a double-sideband noise figure of 9.5 dB, an IIP2 of more than 49 dBm, and an IIP3 of 6.5 dBm. 相似文献
212.
Moon Gi Cho Sung K. Kang Sun-Kyoung Seo Da-Yuan Shih Hyuck Mo Lee 《Journal of Electronic Materials》2009,38(11):2242-2250
The effects of the addition of Zn to Sn-0.7Cu solders are investigated. The study is focused on the interfacial reactions,
microstructures, and mechanical properties after reaction with Ni-P under bump metallurgies (UBMs). The Zn contents in Sn-0.7Cu-xZn are varied as 0.2, 0.4, and 0.8 (in wt.% unless otherwise specified). In the reaction with Ni-P UBM during thermal aging
at 150°C for 1000 h, (Cu,Ni)6Sn5 intermetallic compounds (IMCs) are formed at the Sn-0.7Cu/UBM interface, whereas Zn is incorporated into IMCs to form (Cu,Ni,Zn)6Sn5 in the Zn-doped solders. As the Zn content increases, the interfacial IMC thickness is reduced. A total reduction of about
40% in IMC thickness was observed for the 0.8% Zn-doped Sn-Cu. The same IMC particles are also observed in the matrix of each
solder. In Sn-0.7Cu, (Cu,Ni)6Sn5 particles are coarsened during aging, while (Cu,Ni,Zn)6Sn5 particles in the Zn-added solders are less coarsened and remain much smaller than (Cu,Ni)6Sn5. The growth rate of (Cu,Ni)6Sn5 during thermal aging is significantly suppressed by the addition of Zn. Consequently, after reaction with Ni-P UBM, the Zn-doped
solders exhibit a thermally stable microstructure as measured by hardness and shear strength. 相似文献
213.
Md. Dulal Hossain Junghoon Moon Hyoung Goo Kang Sung Chul Lee Young Chan Choe 《Scientometrics》2012,90(1):57-83
Triple helix (TH) collaborations involving university, industry and government provide a networked infrastructure for shaping
the dynamic fluxes of knowledge base of innovations locally and these fluxes remain emergent within the domains. This study
maps these emergence dynamics of the knowledge base of innovations of Research & Development (R&D) by exploring the longitudinal
trend of systemness within the networked research relations in Bangladesh on the TH model. The bibliometric data of publications
collected from the Science Citation Index (SCI), the social sciences and the arts and humanities for analysis of science indicators
and the patent data collected from the US Patent Office to analyze the patent success ratio as a measure of innovation within
TH domains. The findings show that the network dynamics have varied considerably according to the R&D policies of the government.
The collaboration patterns of co-authorship relations in the SCI publications prominently increased, with some variation,
from 1996 to 2006. Nevertheless, inter-institutional collaboration negatively influenced by the national science and technology
(S&T) research policies in the last 5 years due to their evaluation criteria. Finally, the findings reveal that the R&D system
of Bangladesh is still undergoing a process of institutionalizing S&T and has failed to boost its research capacity for building
the knowledge base of innovations by neglecting the network effects of TH dynamics. 相似文献
214.
Myung-Yeon Cho Sung-Joon Park So-Mang Kim Dong-Won Lee Hong-Ki Kim Sang-Mo Koo Kyoung-Sook Moon Jong-Min Oh 《Ceramics International》2018,44(14):16548-16555
Alumina and polytetrafluoroethylene (Al2O3-PTFE) composite films were fabricated by a simple aerosol deposition (AD) process, to confirm its applicability for various display screens requiring water resistant, anti-smudge and easy-to-clean properties. The surface morphologies, hydrophobic properties, and transparencies of the composite films with different PTFE contents, varying from 0.01 to 1?wt% were investigated. As a result, the composite films with over 0.3?wt% PTFE showed a sudden rise in surface roughness and low transmittance, despite having the highest contact angle of 128° at a PTFE content of 0.3?wt%. From the energy dispersive spectrometer analysis, the crash-cushioning effect of PTFE and agglomerated PTFE particles were determined to be major causes of surface roughness and opacity. In contrast, the transmittance showed a tendency to be enhanced, with an increasing PTFE content in the range of 0.01, 0.05, and 0.1?wt% PTFE, respectively. Especially, the film with 0.1?wt% of PTFE had contact angle of 111° and exhibited a high transmittance of over 75%, which was inferred to be an appropriate amount of PTFE, with a high elongation filling up the surface and the internal defects, leading to an enhancement of transparency. Consequently, these results implied that the AD-prepared Al2O3-PTFE composite coatings are promising candidates for various display applications. 相似文献
215.
216.
Siyoung Yang Seung Jun Choi Jungki Kwak Kihyun Kim Minjae Seo Tae Wha Moon Yin-Won Lee 《Food science and biotechnology》2013,22(2):425-432
Forty-seven strains of Aspergillus oryzae isolates from Korean nuruks were compared for their brewing characteristics. A. oryzae YI-A6 and YI-A7 showed the highest acid α-amylase, glucoamylase, and carboxypeptidase activities, respectively. Sixteen isolates with high amylolytic or proteolytic enzyme activities were selected for investigation of their rice wine fermentation characteristics. After 12 days of brewing at 15°C, ethanol concentrations were 10.2–14.3% for A. oryzae strains. Fermentation rates were the highest for YI-A7. Most rice wine samples fermented with nuruk strains had lower concentrations of off-flavor compounds than the control did. All mean sensory attribute values significantly differed among samples. Pearson correlation coefficients showed that glucoamylase activity was positively correlated to both ethanol productivity and overall harmony (p<0.01). Thus, glucoamylase activity was identified as the best factor for screening Aspergillus strains for use in rice wine brewing. 相似文献
217.
Reduced Beam Section (RBS) moment connections are newly developed connections for Special Moment Resisting Frames (SMRF). This study focuses on Reduced Beam Section with Bolted web connections (RBS-B). Several experiments have demonstrated that some RBS-B connection specimens failed prior to reaching the plastic moment capacity of the reduced beam sections: this may be attributed to insufficient moment strength in the RBS-B connections. This study proposes a new procedure for accurately computing the moment strength for ensuring that a plastic hinge forms in the reduced-section region of the beam, as intended by design. 相似文献
218.
Four chromophores, of different dipole moment and polarizable anisotropy and which comprised conjugation bridges of both benzene and polyene with strong electron-donor and electron-acceptor groups, were characterized using 1H NMR, FT-IR, UV–vis, and electrochemical analyses. The electric dipole moment (μ), polarizability (α) and the first hyperpolarizability (β) values of the chromophores were examined using computational methods. The contribution of orientational birefringence to total birefringence was estimated from the calculated molecular parameters of the chromophores; these parameters are important factors for predicting photorefractive efficiency. 相似文献
219.
Soo-Ho Lee Tae-Won Park Kyeong-Ho Moon Seong-Hoon Choi Kab-Jin Jun 《Journal of Mechanical Science and Technology》2009,23(4):923-926
An AWS (all-wheel-steering) system is applied to the articulated vehicle to satisfy the required steering performance. AWS
ECU (electronic control unit) controls the hydraulic actuator according to vehicle driving environment, such as driver steering
angle, articulating angle, and vehicle velocity. In this paper, the test platform devloped for the AWS ECU black box test
in an HIL( hardware in the loop) environment is explained. Using the developed test platform, the control algorithm of the
AWS ECU can be evaluated under the virtual driving condition of the articulated vehicle. Also, the maneuver of the vehicle
is investigated by using the developed AWS ECU test.
This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008.
Sooho Lee received a B.S. degree in Mechanical Engineering from Ajou University in 2003. He then went on to receive his M.S. degree
from Ajou University in 2005. Mr. Lee is currently a Ph.D student in the School of Mechanical Engineering at Ajou University
in Suwon, Korea. His research interests are in the area of dynamics, vehicle dynamics, control and HILS ( hardware in the
loop simulation). 相似文献
220.
Tumageanian A. Keyhani A. Seung-Ill Moon Leksan T.I. Longya Xu 《Industry Applications, IEEE Transactions on》1994,30(2):433-439
A time-domain system identification procedure to estimate the parameters of a 5 kVA salient pole synchronous machine from standstill test measurements is proposed. The test consists of a DC flux decay signal applied to the d-axis and q-axis of the machine. From the recorded responses to this signal, the admittance transfer function models and the standstill frequency response equivalent circuit models are identified. The maximum likelihood algorithm is used to estimate the model parameter values, and the Akaike Criterion is used to select the best-fit model. The performance of the standstill models in the dynamic environment is studied through simulation of an on-line small-disturbance test. The results are compared with measured data 相似文献