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Speech enhancement with a GSC-like structure employing sparse coding

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第12期15卷 1154-1163页

作者： Li-chun YANG Yun-tao QIAN College of Computer Science and Technology Zhejiang University Intelligent Control Research Institute Zhejiang Wanli University

Speech communication is often influenced by various types of interfering signals. To improve the quality of the desired signal, a generalized sidelobe canceller(GSC), which uses a reference signal to estimate the interfering signal, is attracting attention of researchers. However, the interference suppression of GSC is limited since a little residual desired signal leaks into the reference signal. To overcome this problem, we use sparse coding to suppress the residual desired signal while preserving the reference signal. Sparse coding with the learned dictionary is usually used to reconstruct the desired signal. As the training samples of a desired signal for dictionary learning are not observable in the real environment, the reconstructed desired signal may contain a lot of residual interfering signal. In contrast,the training samples of the interfering signal during the absence of the desired signal for interferer dictionary learning can be achieved through voice activity detection(VAD). Since the reference signal of an interfering signal is coherent to the interferer dictionary, it can be well restructured by sparse coding, while the residual desired signal will be removed. The performance of GSC will be improved since the estimate of the interfering signal with the proposed reference signal is more accurate than ever. Simulation and experiments on a real acoustic environment show that our proposed method is effective in suppressing interfering signals.

关键词： Generalized sidelobe canceller Speech enhancement Voice activity detection Dictionary learning Sparse coding

A New Type of Absorbance Sensors Based on Long-Period Fiber Gratings

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Chinese Physics Letters 2011年第5期28卷 128-131页

作者： luo tao GU Zheng-Tian Laboratory of Photo-electric Functional Films College of ScienceUniversity of Shanghai for Science and TechnologyShanghai 200093

A new absorbance sensor based on long-period fiber gratings(LPFGs)is presented,The measurand is coated on the cladding of the *** is found that the depth of the stop band of the LPFG spectrum will be strongly affected by the absorbance of the measurand if an optimum coating thickness is *** analysis showsthat within the optimal thickness range,the cladding modes could transform into the overlay modes and interact with the measurand more *** absorbance sensitivity of 7×10^(3)is available when the sensor structure is optimized.

关键词： fiber cladding optimum

Green synthesis and enhanced photocatalytic activity of Ce-doped TiO2 nanoparticles supported on porous glass

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Particuology 2017年第5期15卷 103-109页

作者： chun Shen Kexia Pang Le Du Guangsheng luo Beijing Key Laboratory of Bioprocess College of Life Science and Technology Beijing University of Chemical Technology Beijing 100029 China State Key Laboratory of Chemical Resource Engineering Belting Key Laboratory of Membrane Science and Technology Beijing University of Chemical Technology Beijing 100029 China State Key Laboratory of Chemical Engineering Department of Chemical Engineering Tsinghua University Beijing 100084 China

A facile and green method to prepare Ce-doped TiO2 nanoparticles supported on porous glass beads is reported. An ion exchange process and subsequent calcination yielded Ce-doped TiO2 nanoparticles with a mean size of 4.8±0.3 nm. The nanoparticles were dispersed on the surface of porous glass beads. The addition of Ce enhanced the visible light absorption of the TiO2 nanoparticles in the 400-500 nm spectral window. The band gap of the as-prepared catalyst was 2.80 eV. The Ce-doped TiO2 nanoparticles immobilized on porous glass beads exhibited excellent photocatalytic activity for the visible-light-degradation of methyl orange （MO） and rhodamine B （RhB）; with rate constants of 0.095 and 0.230 min^-1 ; respectively. The effects of Ce dosage; reaction duration; and initial solution pH on the conversion of MO and RhB dyes were investigated. The green synthesis and favorable photocatalytic activity makes the Ce-doped TiO2 nanoparticles immobilized on porous glass an attractive alternative for the efficient degradation of organic pollutants.

关键词： Ce-doped TiO2 catalystSupported nanoparticlesPorous glass beadsPhotocatalytic degradation

Effect of phosphogypsum and dicyandiamide as additives on NH_3,N_2O and CH_4 emissions during composting

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Journal of Environmental Sciences 2013年第7期25卷 1338-1345页

作者： Yiming luo Guoxue Li Wenhai luo Frank Schuchardt tao Jiang Degang Xu College of Resource and Environmental Science China Agricultural University Institute of Agricultural Technology and Biosystems Engineering Johann Heinrich von Thuenen-Institute College of Chemistry Leshan Normal University Research Institute of Safety and Environment Technology CNPC

A laboratory scale experiment of composting in a forced aeration system using pig manure with cornstalks was carried out to investigate the effects of both phosphogypsum and dicyandiamide （DCD, C2 H4 N4 ） as additives on gaseous emissions and compost quality. Besides a control, there were three amended treatments with different amounts of additives. The results indicated that the phosphogypsum addition at the rate of 10% of mixture dry weight decreased NH3 and CH4 emissions significantly during composting. The addition of DCD at the rate of 0.2% of mixture dry weight together with 10% of phosphogypsum further reduced the N20 emission by affecting the nitrification process. Reducing the phosphogypsum addition to 5% in the presence of 0.2% DCD moderately increased the NH3 emissions but not N20 emission. The additives increased the ammonium content and electrical conductivity significantly in the final compost. No adverse effect on organic matter degradation or the germination index of the compost was found in the amended treatments. It was recommended that phosphogypsum and DCD could be used in composting for the purpose of reducing NH3 , CH4 and N20 emissions.0ptimal conditions and dose of DCD additive during composting should be determined with different materials and composting systems in further study.

关键词： composting phosphogypsum dicyandiamide greenhouse gas pig manure

Abscisic acid induces differential expression of genes involved in wound-induced suberization in postharvest tomato fruit

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Journal of Integrative Agriculture 2018年第12期17卷 2670-2682页

作者： HAN Xue-yuan MAO Lin-chun LU Wen-jing tao Xiao-ya WEI Xiao-peng luo Zi-sheng College of Biosystems Engineering and Food Science/Fuli Institute of Food Science/Zhejiang Key Laboratory of AgroFood Processing Zhejiang University

Fruit wounding occurred at harvest and transportation requires rapid suberization as a major part of the healing process to prevent infection and desiccation. The focus of this work was to explore the mediation of abscisic acid(ABA) on woundinduced suberization and to determine expression profiles of specific genes involved in wound-induced suberization in tomato fruit. The measurements of weight loss and fruit firmness suggested wound-induced suberization started at 2 d after wounding. The suberization process with the accumulation of suberin polyphenolics(SPP) and polyaliphatics(SPA) observed through autofluorescence microscopy and Sudan IV staining was accelerated by ABA. Expressions of SlPAL5 and Sl4 CL involved in the synthesis of SPP reached the highest at 4 and 8 d after wounding following ABA application, respectively. Associated with SPA biosynthesis, SlLACS1 and SlLACS2 showed the most abundant transcripts at 8 and 6 d in ABA group, respectively. Transcript levels including SlKCSs, SlCYP86 B1, SlFAR3, and Sl GPATs were up-regulated at 2 d after wounding by ABA. Activities of polyphenol oxidase and lipoxygenase were also enhanced during wound-induced suberization following ABA application. The results in this study proved that ABA accelerated the wound-induced suberization progress by increasing the transcript levels of relevant genes in postharvest tomato fruit.

关键词： tomato abscisic acid wound-induced suberization genes

The Impulse Excitation Joint Servo Drive Design and Adaptive Backstepping Control of Humanoid Robots

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Journal of Bionic Engineering 2018年第1期15卷 114-125页

作者： Kcqiang Bai Minzhou luo tao Li Jue Wu Southwest University of Science and Technology Mianyang 621010 China Department of Automation School of Information Science of Technology University of Science and Technology of China Hefei 230026 China Institute of Advanced Manufacturing and Technology Hefei Institute of Physical Science Chinese Academy of Sciences Changzhou 213164 China

This study aims to explore the humanoid robot joint servo drive integration design and adaptive backstepping control. To make the humanoid robot have explosive power as the human does, simply increasing the power output of the motor of a lightweight design cannot meet the demand of moving heavy objects and so on. Moreover, the backstepping control algorithm is designed to implement the dual-arm cooperative control. The joint servo drive is redesigned in the present study, which can drive the motor at a limitation state when needed output high-voltage pulse can stimulate the motor so that the motor can produce an instantaneous large torque. A miniature design scheme is presented in this study for the servo drive, explaining the design method of each part module. The ex- perimental data illustrate that the servo drive can produce an output torque greater than the rate of the high-voltage pulse that stimulates the motor. Knowledge of the control of humanoid robot moving a heavy object has important practical significance. The present study provides a complete actual problem and exhibits a real practical use case which can be used to speed up the explosive humanoid robot arms.

关键词： adaptive backstepping control bionic robot drive integration design impulse excitation servo drive

Optimal synthesis of compression refrigeration system using a novel MINLP approach

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1662-1669页

作者： tao Yang Yiqing luo Yingjie Ma Xigang Yuan School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China State Key Laboratory of Chemical Engineering Tianjin University Tianjin 300072China

The optimal design of a compression refrigeration system(CRS) with multiple temperature levels is very important to chemical process industries and also represents considerable challenges in process systems engineering. In this paper, a general methodology for the optimal synthesis of the CRS, which simultaneously integrates CRS and Heat Exchanger Networks(HEN) to minimize the total compressor shaft work consumption based on an MINLP model, has been proposed. The major contribution of this method is in addressing the optimal design of refrigeration cycle with variable refrigeration temperature levels. The method can be used to make major decisions in the CRS design, such as the number of levels, temperature levels, and heat transfer duties. The performance of the developed methodology has been illustrated with a case study of an ethylene CRS in an industrial ethylene plant, and the optimal solution has been examined by rigorous simulations in Aspen Plus to verify its feasibility and consistency.

关键词： Optimal design Compression refrigeration system (CRS) Chemical process Process systems Compressor shaft work Mixed Integer Nonlinear Programming (MINLP)

Energy-efficient Bio-inspired Gait Planning and Control for Biped Robot Based on Human Locomotion Analysis

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Journal of Bionic Engineering 2016年第2期13卷 271-282页

作者： Hongbo Zhu Minzhou luo tao Mei Jianghai Zhao tao Li Fayong Guo Department of Automation School of Information Science and Technology University of Science and Technology of China Hefei 230022 China Institute of Advanced Manufacturing Technology Hefei Institutes of Physical Science Chinese Academy of Sciences Changzhou 213164 China

In this paper an experiment of human locomotion was carried out using a motion capture system to extract the human gait features. The modifiable key gait parameters affecting the dominant performance of biped robot walking were obtained from the extracted human gait features. Based on the modifiable key gait parameters and the Allowable Zero Moment Point （ZMP） Variation Region （AZR）, we proposed an effective Bio-inspired Gait Planning （BGP） and control scheme for biped robot to- wards a given travel distance D. First, we construct an on-line Bio-inspired Gait Synthesis algorithm （BGSN） to generate a complete walking gait motion using the modifiable key gait parameters. Second, a Bio-inspired Gait Parameters Optimization algorithm （BGPO） is established to minimize the energy consumption of all actuators and guarantee biped robot walking with certain walking stability margin. Third, the necessary controllers for biped robot were introduced in briefly. Simulation and experiment results demonstrated the effectiveness of the proposed method, and the gait control system was implemented on DRC-XT humanoid robot.

关键词： motion capture Allowable Zero Moment Point (ZMP) Variation Region (AZR) Bio-inspired Gait Planning (BGP) humanoid robot

A Unified Dynamic Control Method for a Redundant Dual Arm Robot

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Journal of Bionic Engineering 2015年第3期12卷 361-371页

作者： Meiling Wang Minzhou luo tao Li Marco Ceccarelli Department of Automation University of Science and Technology of China Hefei 230026 China Institute of Advanced Manufacturing Technology Hefei Institute of Physical Science Chinese Academy of Sciences Changzhou 213164 China LARM Laboratory of Robotics and Meehatronies DiMSAT-University of Cassino Via Di Biasio 43 03043 Cassino (Fr) Italy

Compared to single arm robot system, dual arm robot has the ability of performing human-like dexterity and cooperation. Dual arm cooperative operation has attracted more and more attention in industrial applications, such as in assembly of complex parts, manufacturing tasks and handling objects. A unified dynamic control method, which is divided into three modes, namely, independent mode, dependent mode, and half dependent mode, is proposed for a redundant dual arm robot with focus on the movement and force of the desired task being operated. Attention is devoted to develop a unified formulation of the above three modes. In addition, a closed form of inverse kinematic solution instead of numerical integration approach is proposed with the aim to guarantee position accuracy. Different from traditional dynamic controllers, where the independent redundancy resolution is obtained based on particular velocity or acceleration levels, here the two dynamic controllers are improved by combining a closed form of inverse kinematic solution with velocity and acceleration levels. Furthermore, the theoretical results of the proposed control method are validated by simulations and experiments.

关键词： unified control method dual arm robot dynamic constraints intemal force