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A noise cross PSD estimator for dual-microphone speech enhancement based on minimum statistics

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 805-809页

作者： Mohsen RAHMANI Ahmad AKBARI Beghdad AYAD Nima DERAKHSHAN research center for information Technology Computer DepartmentIran University of Science and Technology

Some two-microphone noise reduction techniques that work in the frequency domain exploit coherence function between two noisy signals. They have shown good results when noise signals on two sensors are uncorrelated, but their per-formance decreases with correlated noises. Coherence based methods can be improved when the cross power spectral density (CPSD) of correlated noise signals is available. In this paper, we propose a new method for estimation of the CPSD of the noise, which is based on the minimum tracking technique. Despite the fact that the proposed estimator does not need to implement a voice activity detector (VAD), its performance is comparable to a CPSD estimator that uses an ideal VAD.

关键词： Two-channel noise reduction Noise estimation Minima tracking

Improved Rao-Blackwellized H_∞ filter based mobile robot SLAM

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The Journal of China Universities of Posts and Telecommunications 2016年第5期23卷 47-55页

作者： Luo Yuan Su Qin Zhang Yi Zheng Xiaofeng research center of information Accessibility and Robotics Chongqing University of Posts and Telecommunications

For the problems of estimation accuracy, inconsistencies and robustness in mobile robot simultaneous localization and mapping （SLAM）, a novel SLAM based on improved Rao-Blackwellized H∞ particle filter （IRBHF-SLAM） algorithm is proposed. The iterated unscented H∞ filter （IUHF） is utilized to accurately calculate the importance density function, repeatedly correcting the state mean and the covariance matrix by the iterative update method. The laser sensor＇s observation information is introduced into sequential importance sampling routine. It can avoid the calculation of Jacobian matrix and linearization error accumulation; meanwhile, the robustness of the algorithm is enhanced. IRBHF-SLAM is compared with FastSLAM2.0 and the unscented FastSLAM （UFastSLAM） under different noises in simulation experiments. Results show the algorithm can improve the estimation accuracy and stability. The improved approach, based on the robot operation system （ROS）, runs on the Pioneer3-DX robot equipped with a HOKUYO URG-04LX （URG） laser range finder. Experimental results show the improved algorithm can reduce the required number of particles and the operating time; and create online 2 dimensional （2-D） grid-map with high precision in different environments.

关键词： SLAM Rao-Blackwellized particle filter iterated unscented H∞ filter ROS

Synthesis of carbon nanofibers by ethanol catalytic combustion technique

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Journal of Central South University of Technology 2008年第1期15卷 15-19页

作者：李飞邹小平程进张红丹任鹏飞王茂发朱光 research center for Sensor Technology Beijing Information Technology Institute

A general, simple and economic synthetic method for synthesizing carbon nanofibers was presented. In the method, ethanol was employed as carbon source; metal salts such as nickel nitrate, ferric nitrate and ferric chloride were used as catalyst precursor respectively; copper plate was employed as the support material. A lot of products were obtained by catalytic combustion deposition of ethanol vapor. Then the as-prepared carbon nanofibers were characterized by field-emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, energy dispersion X-ray spectroscopy and selected-area electron diffractometry. By analyzing the results of characterization, the conclusions are as follows: 1) the large catalyst particles tend to form large-diameter CNFs, small catalyst particles are inclinable to form small-diameter CNFs; 2) the morphology of the catalyst can affect the final morphology of the CNFs. Moreover, the possible growth mechanisms were proposed and the degree of graphitization of samples was estimated by Raman spectroscopy characterization.

关键词： synthesis ethanol catalytic combustion carbon nanofibers growth mechanism degree of graphitization

Effect of initial-state target polarization on the single ionization of helium by 1-keV electron impact

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Chinese Physics B 2012年第7期21卷 275-279页

作者：孙世艳马晓艳李霞苗向阳贾祥富 center for Molecules research School of Physics and Information EngineeringShanxi Normal University

We report new results of triple differential cross sections for the single ionization of helium by 1-KeV electron impact at the ejection energy of 10 eV. Investigations have been made for both the perpendicular plane and the plane perpendicular to the momentum transfer geometries. The present calculation is based on the threewCoulomb wave function. Here we have also incorporated the effect of target polarization in the initial state. A comparison is made between the present calculation with the results of other theoretical methods and a recent experiment [Diirr M, Dimopoulou C, Najjari B, Dorn A, Bartschat K, Bray I, Fursa D V, Chen Z, Madison D H and Ullrich J 2008 Phys. Rev. A 77 032717]. At an impact energy of 1 KeV, the target polarization is found to induce a substantial change of the cross section for the ionization process. We observe that the effect of target polarization plays a dominant role in deciding the shape of triple differential cross sections.

关键词： triple differential cross section target polarization non-coplanar geometry

Enhancing stationary entanglement between two optomechanical oscillators by Coulomb interaction with Kerr medium

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Chinese Physics B 2021年第12期30卷 406-412页

作者： Tian-Le Yang Chen-Long Zhu Sheng Liu Ye-Jun Xu International research center of Quantum information and Photoelectric information School of Mechanical and Electronic EngineeringChizhou UniversityChizhou 247000China

We theoretically study the stationary entanglement of two charged nanomechanical oscillators coupling via Coulomb interaction in an optomechanical system with an additional Kerr *** show that the degree of entanglement between two nanomechanical oscillators is suppressed by Kerr interaction due to photon blockade and enhanced by Coulomb coupling *** also show other parameters for adjusting and obtaining entanglement,such as the driving power and the frequencies of the two oscillators,and the entanglement is robust against *** study proves a way for adjusting stationary entanglement between two optomechanical oscillators by Coulomb interaction and Kerr medium.

关键词： entanglement Kerr interaction Coulomb interaction optomechanics

Theoretical analysis on fully differential cross sections for C^(6+)impact ionization of helium

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Chinese Physics B 2014年第6期23卷 188-192页

作者：方小英张瑞芳段慧晓孙世艳贾祥富 center for Molecules research School of Physics and Information Engineering Shanxi Normal University

Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.

关键词： ion-impact ionization fully differential cross section four-body model interference effect

The development of spatial decision support system tool for marine spatial planning

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International Journal of Digital Earth 2018年第9期11卷 863-879页

作者： Dewayany Sutrisno Suzan Novtalia Gill Suseno Suseno center for research Promotion and CooperationGeospatial Information Agency(BIG)CibinongIndonesia center for Institutional Standardization of Geospastial information Geospatial Information Agency(BIG)CibinongIndonesia center for Management and Dissemination of Geospatial information Geospatial Information Agency(BIG)CibinongIndonesia

A major problem associated with marine spatial planning(MSP)involves the difficult and time-consuming practice of creating a scenario that encompasses complex datasets in near real time via the use of a simple spatial analysis ***,decision-makers require a reliable,user-friendly system to quickly and accessibly acquire accurate spatial planning *** development of national spatial data infrastructure(NSDI),which links the spatial data of a nation’s many diverse institutions,may pave the way for the development of a tool that can better utilize spatial datasets,such as a spatial decision support system(SDSS).Thus,this project aimed to develop an SDSS for MSP and to evaluate the feasibility of its integration within the NSDI *** seaweed culture was selected as an example due to its economic and technological acceptance by traditional ***,a multicriteria analysis was used to develop the ***,a feasibility evaluation of its implementation within the NSDI framework was conducted based on the Delphi *** results of the assessment indicated that the SDSS can be incorporated into the NSDI framework by addressing the policy issue–one map policy,updating custodians’decree and data,and improve the standard and protocol.

关键词： Spatial data infrastructure spatial decision support system marine spatial planning seaweed culture

Multi-algorithm Fusion Framework for Energy Prediction of Energy Harvesting IoT Node and Implementation

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Chinese Journal of Electronics 2020年第5期29卷 952-958页

作者： LI Xiangyu XIE Nijie Institute of Microelectronics Tsinghua University Beijing National research center for information Science and Technology

Accurate harvested energy prediction of the energy harvesting Internet-of-things(IoT) nodes is the basis of the proper power management and should be lowoverhead. A new multi-algorithm fusion framework, which merges results of multiple prediction algorithms to achieve a higher accuracy, has been proposed. A three-algorithm fusion solar radiation predictor was implemented. The experiments using the real solar radiation data show that it improves the percentage prediction error by 10%–26% for different prediction intervals. Its complexity is low enough to run on the embedded systems in real-time.

关键词： Energy harvesting Energy prediction Multi-algorithm fusion Internet-of-things

Enantioselective separation and zebrafish embryo toxicity of insecticide beta-cypermethrin

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Journal of Environmental Sciences 2010年第5期22卷 738-743页

作者： Chao Xu,Wenqing Tu,Chun Lou,Yingying Hong,Meirong Zhao research center of Environmental Science,College of biological and Environmental Engineering,Zhejiang University of Technology,Hangzhou 310032,China. research center of Environmental Science College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032 China

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between *** this study,enantiomers of insecticide beta-cypermethrin （beta-CP） were separated on selected chiral column by HPLC,and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval *** enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism （CD） at 236 *** separation could be achieved at lower temperature （e.g.,20°C） and with lower levels of polar *** enantiomers were obtained on Chiralcel *** CD spectra of enantiomers were *** comparing the elution order with a previous similar study,the absolute configuration of beta-CP enantiomers was *** individual enantiomers were used in zebrafish embryo test,and the results showed that beta-CP enantioselectively induced yolk sac edema,pericardial edema and crooked *** 1R-cis-αS and 1R-trans-αS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L,while the 1S-cis-αR and 1S-trans-αR induced no malformations at higher concentration （e.g.,0.3 mg/L）.The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.

关键词： beta-cypermethrin enantioselectivity zebrafish embryo chiral separation