1IntroductionInthelast decades ,manyauthors studiedrobust quadraticstabilization control of deterministic linear systems withparameter uncertainty or structured uncertainty, see[1 ~8] . Robust quadratic stability and stabilization ofdeterministic systems were first introduced by [1] ,bymeans of a common Lyapunovfunction.Most earlier resultson robust quadratic stabilization,including some necessaryand sufficient conditions , were expressed in terms ofRiccati_type equations or inequalities , wh… 相似文献
1 Introduction Fluid inclusion is a blocked mineralizing medium captured because of crystal defects during mineral growth. It is an original sample in the basin and con- tains abundant information of geological history [1]. Therefore, the application of fluid inclusion in study- ing oil-gas geology becomes increasingly impor- tant[2–3]. There are many successful examples of such application both at home and abroad [4–9]. Although there have been some studies made in the Ordos basin on fluid… 相似文献
The flow patterns of the gas-liquid two-phase flow in a Moving-Bed Biofilm Reactor (MBBR) have a critical effect upon the mass transfer by the convection.Bubble plumes promote unsteadily fluctuating two-phase flows during the aeration.This article studies the unsteady structure of bubble plumes through experiments.The time-serial bubble plume images in various cases of the tank are analyzed.The Recursive Cross Correlation-Particle Image Velocimetry (RCC-PIV) is used to calculate the velocities in those cases, and then the time-serial vortex, the total turbulence intensity, the time-serial streamline are obtained.It is shown that the aspect ratio and the void fraction are the dominant factors influencing the unsteady structure of bubble plumes.When the aspect ratio is unity and the void fraction is high, the bubble plumes see a symmetrical vortex structure with a long residence time, which is beneficial for optimizing the aeration system and enhancing the applied range of bubble plumes. 相似文献
By constructing an accumulated-crossover relationship in multiple parallel concatenated single parity check (M-PC-SPC) codes,
a class of error-correcting codes, termed multiple accumulated-crossover parallel concatenated single parity check (M-ACPC-SPC)
codes, is proposed. M-ACPC-SPC codes possess linear encoding complexity and can be decoded iteratively with low complexity
by the sum-product algorithm (SPA). Simulation results show that M-ACPC-SPC codes have lower error floors than M-PCSPC codes
with the same dimension, and when the dimension is 5, M-ACPC-SPC codes achieve bit error rate (BER) better than (3, 6) regular
low density parity check (LDPC) codes.
Supported by the National High-Tech Research & Development Program of China (Grant No. 2007AA01Z288), the National Science
Fund for Distinguished Young Scholars (Grant No. 60725105), the Program for Changjiang Scholars and Innovative Research Team
in University and the 111 Project (Grant No. B08038) 相似文献
A new approach for unparallel trajectory bistatic spotlight SAR imaging is proposed. The approach utilizes the concept of
instantaneous Doppler wavenumber and introduces two variants, the sum-range and subtraction-range, to develop the 2D frequency
analytical formula. Based on the assumption of plane wavefront, the transmitting and receiving Doppler are separated and formulated
via series reversion. And frequency scaling is applied to focus image. The algorithm is with high computational efficiency,
and provides well focus for limited scene imaging. Simulation result confirms the validity of the approach.
Supported by the National Natural Science Foundation of China (Grant No. 60502044) and Program for New Century Excellent Talents
in University (Grant No. NCET-06-0861) 相似文献
A two-user cooperative diversity system based on Alamouti signaling was proposed, which utilizes the orthogonal structure
of Alamouti signaling to make cooperative users relay on the shared channel resources so that the spectral efficiency of the
traditional cooperative system can be improved. When M-ary phase shift keying (M-PSK) modulation and an improved selection decode-and-forward (SDF) relaying protocol with limited feedback are used at the
users and m(m ⩾1) receive antennas are configured at the base station, the average bit-error-rate (BER) system performance for statistically
similar uplink channels was derived and it was verified by simulations. Under various channel scenarios of interest, numerical
and simulation results show that the diversity gain achieved and the BER performance of the proposed system increase with
the interuser channel quality, and the full transmit diversity order of two can be obtained for sufficiently high interuser
signal-to-noise ratios (SNRs).
Supported by the National High-Tech Research & Development Program of China (Grant No. 2006AA01Z270), the National Natural
Science Foundation of China-Guangdong (Grant No. U0635003), the Natural Science Foundation of Shaanxi Province (Grant No.
2007F07), the “111” Project (Grant No. B08038), and the Open Research Fund of State Key Laboratory of Rail Traffic Control
and Safety, Bejing Jiaotong University (Grant No. RCS2008K003) 相似文献
We describe a method to construct an n-variable (n even) almost optimal resilient Boolean function via concatenating 2 d properly chosen (n-d)-variable Maiorana-McFarland functions.As an example,a 5-resilient 42-variable Boolean function with currently best known nonlinearity 2 41-2 20-2 17 is provided. 相似文献