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Maoming, China

Xie S.-L.,South China University of Technology | Sun G.-X.,South China University of Technology | Xiao M.,South China University of Technology | Xiao M.,Maoming College | And 2 more authors.
Tien Tzu Hsueh Pao/Acta Electronica Sinica

Two-step strategy has become a fundamental method for underdetermined blind signal separation and the estimation of mixing matrix is a prerequisite for the source's recovery. This paper proposes a two-step blind source extraction method for incompletely sparse case. The approach firstly estimates the basis vectors (columns of matrix) of partial sources using single-source intervals and then extracts the corresponding sources with minimum interference;it doesn't depend on other basis vector except the corresponding basis vector, so it avoids the essential condition the matrix is recoverable. Several simulation experimental results demonstrate its performance and practices. Source

Liu J.,Zhejiang University | Liu J.,Maoming College | Ren Y.,Zhejiang University | Yao S.,Zhejiang University
Chinese Journal of Chemical Engineering

In general, productions of natural pigment in submerged microorganism culture were much less than that in solid-state fermentation, because the solid-state culture can provide a support carrier for the mycelium. To~improve~natural~pigment~production, the cultivation of Monascus purpureus in submerged encapsulated cell was investigated. Monascus purpureus immobilized in polyelectrolyte complex (PEC) microcapsules, which were prepared by sodium cellulose sulphate (NaCS) and poly-dimethyl-diallyl-ammonium chloride (PDMDAAC), was a good substitute for submerged cell culture because it mimicked the solid-state environment. The repeated-batch process with encapsulated cells was studied in flasks and a bubble column. The results indicated that the bubble column was more suitable for the encapsulation culture than the shaking flasks because of its good mass transfer performance and minor shear stress on cells. Owing to the protection of the microcapsule's membrane, Monascus purpureus in microcapsules increased approximately three times over that in free cell culture with negligible cell leakage to the medium. The pigment production in the bubble column finally reached 3.82 (OD 500), which was two times higher than in free cell culture. In addition, the duration of each batch was shortened to 15 of that in free cell culture. © 2010 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP). Source

Li Q.-X.,Maoming College
3CA 2010 - 2010 International Symposium on Computer, Communication, Control and Automation

Accuracy of single filter used in most of vehicle navigation decreases when system state is both linear and nonlinear. According to the output state of the receiver to choose linear or nonlinear filter, a kind of combined filtering structure is proposed. Furthermore, a derivative- free filter is adopted as nonlinear filter, especially, formulas of state and random noise covariance matrix's Cholesky decomposition update are improved, which guarantees positive definiteness of covariance matrix and its square root; Due to high precision and robust performance of linear Kalman filter on linear filtering, it's filtering equations are improved to eliminate positioning error caused by velocity error; The advantages of two filters are verified in static and dynamic process respectively by simulation experiment. Finally, vehicle simulation results show that the combined linear- nonlinear filter has low error and computation cost, is better than single filter. © 2010 IEEE. Source

Hu S.,Maoming College | Fu G.,Guangzhou University
Sensors and Actuators, A: Physical

Ceramic humidity sensitive samples composed of the SnO2- LiZnVO4 system were synthesized in liquid state and characterized by SEM. Compared with the sample synthesized in conventional solid-state reaction, the sample synthesized in liquid state has the advantages of lower impedance in the low relatively humidity (RH) range and better impedance-RH linearity. The effect of different levels of liquid-state doping of LiZnVO4 on the humidity-sensitive characteristics was studied. It was found that humidity-sensitive characteristics and microstructure can be improved by controlling the level of liquid-doped LiZnVO4. The best results were obtained with the 10 mol% LiZnVO4-doped sample, which exhibited excellent linearity in the humidity range of 11-93% RH. An impedance variation of more than four orders of magnitude, better impedance-RH linearity, high BET surface area, a narrow hysteresis loop, and rapid response were obtained. SEM micrographs of the grain structures and complex impedance analysis confirm that high performance of the sensitive layer is associated with a fine microstructure morphology, which is characterized by suitable rod shaped grains forming mesopores and by well-distributed LiZnVO4 additives, forming a thin glassy surface covering. © 2010 Elsevier B.V. All rights reserved. Source

Hu S.,Maoming College | Fu G.,Guangzhou University | Chen H.,Maoming College
Yadian Yu Shengguang/Piezoelectrics and Acoustooptics

The microstructure and humidity-sensitive characteristics of SnO2-LiZnVO4 system humidity-sensitive ceramics were studied by comparing the method of urea co-precipitation with the method of ammonia co-precipitation. The influence of the amount of liquid-doped LiZnVO4 on the humidity-sensitive characteristics was researched. The experimental results showed that the SnO2-LiZnVO4 system humidity-sensitive material prepared by the co-precipitation with urea and ammonia were characterized by the rod and ball shaped grains respectively. Humidity-sensitive characteristics indicated that humidity-sensitive characteristics of the material is best with 10% liquid-doped LiZnVO4 in the both co-precipitation SnO2 powders. But the material with rod shaped grains characterized lower resistance at lower humidity and with proper humidity sensitivity than that with ball grain. The characteristics of frequencies showed that the material with rod and ball grain both have better respond to frequencies. The characteristics of stabilizations showed that the sample with rod shaped grains was more stationary than that with ball shaped grains. Source

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