145 research outputs found

    Kalman Filtering for Genetic Regulatory Networks with Missing Values

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    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

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    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

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    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

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    Zn-doped Sbā‚‚Te films are proposed to present the feasibility for phase-change memory application. Zn atoms are found to significantly increase crystallization temperature of Zn x (Sbā‚‚Te)1āˆ’x films and be almost linearly with the wide range of Zn-doping concentration from xā€‰=ā€‰0 to 29.67 at.%. Crystalline resistances are enhanced by Zn-doping, while keeping the large amorphous/crystalline resistance ratio almost constant at āˆ¼10āµ. Especially, the Zn 26.07 (Sbā‚‚Te)73.93 and Zn 29.67 (Sbā‚‚Te)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 Sbā‚‚Te crystalline grains

    Improved phase-change characteristics of Zn-doped amorphous Sbā‚‡Teā‚ƒ films for high-speed and low-power phase change memory

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    The superior performance of Zn-doped Sbā‚‡Teā‚ƒ 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 Sbā‚‡Teā‚ƒ film. Especially, Zn 30.19(Sbā‚‡Teā‚ƒ)69.81 film has higher crystallization temperature (āˆ¼258ā€‰Ā°C), larger crystallization activation energy (āˆ¼4.15ā€‰eV), better data retention (āˆ¼170.6ā€‰Ā°C for 10ā€‰yr), wider band gap (āˆ¼0.73ā€‰eV), and higher crystalline resistance. The minimum times for crystallization of Zn 30.19(Sbā‚‡Teā‚ƒ)69.81 were revealed to be as short as āˆ¼10ā€‰ns at a given proper laser power of 70ā€‰mW.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 Geā€“Gaā€“Teā€“CsBr Glass System with Ultrahigh Resolvability of Halide

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    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 Geā€“Gaā€“Te glass. Geā€“Gaā€“Te 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, Ī”T values of these glass samples were all above 100 Ā°C. The glass sample (Ge15Ga10Te75)65 (CsBr)35 with Ī”T 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 Geā€“Gaā€“Te far-infrared chalcogenide glasses

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    International audienceIn this study, a novel Te-based glass system was investigated. Some properties of Geā€“Gaā€“Teā€“NaI 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 (Ī”T > 100 Ā°C) and the highest Ī”T value corresponding to (Ge15Ga10Te75)85(NaI)15 glass is 120 Ā°C which is 8 Ā°C greater than that of Geā€“Gaā€“Te host glass. The infrared spectra manifest Geā€“Gaā€“Teā€“NaI chalcogenide glass system has a wide infrared transmission window between 1.6 Ī¼m and 20 Ī¼m. Consequently, Geā€“Gaā€“Teā€“NaI glasses can be a candidate material for far infrared optic imaging and bio-sensing application
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