145 research outputs found
Kalman Filtering for Genetic Regulatory Networks with Missing Values
The filter problem with missing value for genetic regulation networks (GRNs) is addressed, in which the noises exist in both the state dynamics and measurement equations; furthermore, the correlation between process noise and measurement noise is also taken into consideration. In order to deal with the filter problem, a class of discrete-time GRNs with missing value, noise correlation, and time delays is established. Then a new observation model is proposed to decrease the adverse effect caused by the missing value and to decouple the correlation between process noise and measurement noise in theory. Finally, a Kalman filtering is used to estimate the states of GRNs. Meanwhile, a typical example is provided to verify the effectiveness of the proposed method, and it turns out to be the case that the concentrations of mRNA and protein could be estimated accurately
Digital Closed-Loop Driving Technique Using the PFD-Based CORDIC Algorithm for a Biaxial Resonant Microaccelerometer
A digital closed-loop driving technique is presented in this paper that uses the PFD- (phase frequency detector-) based CORDIC (coordinate rotation digital computer) algorithm for a biaxial resonant microaccelerometer. A conventional digital closed-loop self-oscillation system based on the CORDIC algorithm is implemented and simulated using Simulink software to verify the system performance. The system performance simulations reveal that the incompatibility between the sampling frequency and effective bits of AD and DA convertors limits further performance improvements. Therefore, digital, closed-loop self-oscillation using the PFD-based CORDIC algorithm is designed to further optimize the system performance. The system experimental results illustrate that the optimized system using the PFD-based CORDIC improves the bias stability of the resonant microaccelerometer by more than 5.320 times compared to the conventional system. This demonstrates that the optimized digital closed-loop driving technique using the PFD-based CORDIC for the biaxial resonant microaccelerometer is effective
Phase change behaviors of Zn-doped Ge2Sb2Te5 films
This work was financially supported by the Program for
New Century Excellent Talents in University (Grant No.
NCET-10-0976), the International Science & Technology
Cooperation Program of China (Grant No. 2011DFA12040),
the National Program on Key Basic Research Project (973
Program) (Grant No. 2012CB722703), the Natural Science
Foundation of China (Grant Nos. 61008041 and 60978058),
the Natural Science Foundation of Zhejiang Province, China
(Grant No. Y1090996), the Natural Science Foundation of
Ningbo City, China (Grant No. 2011A610092), the Program
for Innovative Research Team of Ningbo city (Grant No.
2009B21007), and sponsored by K. C. Wong Magna Fund in
Ningbo University
Enhanced thermal stability and electrical behavior of Zn-doped Sb2Te films for phase change memory application
Zn-doped SbāTe films are proposed to present the feasibility for phase-change memory application. Zn atoms are found to significantly increase crystallization temperature of Zn x (SbāTe)1āx films and be almost linearly with the wide range of Zn-doping concentration from xā=ā0 to 29.67 at.%. Crystalline resistances are enhanced by Zn-doping, while keeping the large amorphous/crystalline resistance ratio almost constant at ā¼10āµ. Especially, the Zn 26.07 (SbāTe)73.93 and Zn 29.67 (SbāTe)70.33 films exhibit a larger resistance change, faster crystallization speed, and better thermal stability due to the formation of amorphous Zn-Sb and Zn-Te phases as well as uniform distribution of SbāTe crystalline grains
Improved phase-change characteristics of Zn-doped amorphous SbāTeā films for high-speed and low-power phase change memory
The superior performance of Zn-doped SbāTeā films might be favorable for the application in phase change memory. It was found that Zn dopants were able to suppress phase separation and form single stable Sb2Te crystal grain, diminish the grain size, and enhance the amorphous thermal stability of SbāTeā film. Especially, Zn 30.19(SbāTeā)69.81 film has higher crystallization temperature (ā¼258āĀ°C), larger crystallization activation energy (ā¼4.15āeV), better data retention (ā¼170.6āĀ°C for 10āyr), wider band gap (ā¼0.73āeV), and higher crystalline resistance. The minimum times for crystallization of Zn 30.19(SbāTeā)69.81 were revealed to be as short as ā¼10āns at a given proper laser power of 70āmW.This work was financially supported by the International
Science & Technology Cooperation Program of China
(Grant No. 2011DFA12040), the National Program on Key
Basic Research Project (973 Program) (Grant No.
2012CB722703), the Natural Science Foundation of China
(Grant Nos. 61008041 and 60978058), the CAS Special
Grant for Postgraduate Research, Innovation and Practice,
the Program for Innovative Research Team of Ningbo city
(Grant No. 2009B21007), and sponsored by K. C. Wong
Magna Fund in Ningbo University
Novel GeāGaāTeāCsBr Glass System with Ultrahigh Resolvability of Halide
International audienceCO2 molecule, one of the main molecules to create new life, should be probed accurately to detect the existence of life in exoplanets. The primary signature of CO2 molecule is approximately 15 Ī¼m, and traditional S- and Se-based glass fibers are unsuitable. Thus, Te-based glass is the only ideal candidate glass for far-infrared detection. In this study, a new kind of Te-based chalcohalide glass system was discovered with relatively stable and large optical band gap. A traditional melt-quenching method was adopted to prepare a series of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glass samples. Experiment results indicate that the glass-forming ability and thermal properties of glass samples were improved when CsBr was added in the host of GeāGaāTe glass. GeāGaāTe glass could remarkably dissolve CsBr content as much as 85 at.%, which is the highest halide content in all reports for Te-based chalcohalide glasses. Moreover, ĪT values of these glass samples were all above 100 Ā°C. The glass sample (Ge15Ga10Te75)65 (CsBr)35 with ĪT of 119 Ā°C was the largest, which was 7 Ā°C larger than that of Ge15Ga10Te75 host glass. The infrared transmission spectra of these glasses show that the far-infrared cut-off wavelengths of (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses were all beyond 25 Ī¼m. In conclusion, (Ge15Ga10Te75)100-x (CsBr)x chalcogenide glasses are potential materials for far-infrared optical applicatio
Novel NaI improved GeāGaāTe far-infrared chalcogenide glasses
International audienceIn this study, a novel Te-based glass system was investigated. Some properties of GeāGaāTeāNaI chalcogenide glasses such as physical, thermal and optical transmitting were discussed. XRD patterns show this glass system with best amorphous state can dissolve content of NaI as much as 35 at.%. The lowest cut-off wavelength of glass samples is 1645 nm which is the smallest wavelength among the reported Te-based glasses doping with halide. DSC curves indicate that all glass samples have good thermal stabilities (ĪT > 100 Ā°C) and the highest ĪT value corresponding to (Ge15Ga10Te75)85(NaI)15 glass is 120 Ā°C which is 8 Ā°C greater than that of GeāGaāTe host glass. The infrared spectra manifest GeāGaāTeāNaI chalcogenide glass system has a wide infrared transmission window between 1.6 Ī¼m and 20 Ī¼m. Consequently, GeāGaāTeāNaI glasses can be a candidate material for far infrared optic imaging and bio-sensing application
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