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Dispersion compensation in an open-loop all-optical chaotic communication system

Chinese Physics B 2012年第4期21卷 138-144页

作者：刘慧杰任斌冯久超 School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China Department of Electronic Engineering Dongguan University of TechnologyDongguan 523808China

The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation （CM） or chaotic shift keying （CSK）. The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate （1 Gb/s）, the post-compensation map is the best scheme. However, for the message of higher bit rate （2.5 Gb/s）, the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system.

关键词： chaotic communication dispersion compensation semiconductor lasers strong injection open-loop configuration

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Diagnosis of open-switch faults in variable speed drives by stator current analysis and pattern recognition

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IET ELECTRIC POWER APPLICATIONS 2013年第6期7卷 509-522页

作者： Ulises Campos-Delgado, Daniel Angel Pecina-Sanchez, Jose Rivelino Espinoza-Trejo, Diego Roman Arce-Santana, Edgar UASLP COARA Matehuala Mexico

This study addresses the problem of detection and isolation of open-switch faults in voltage source inverters by processing the stator current measurements. First, the resulting post-fault trajectories for the stator currents are analytically derived for single and concurrent faults (21 classes) by using Fourier series. This analysis motivated the proposed approach, which is based on the resulting pattern of the stator currents in the dq-frame after a fault, where a histogram of the trajectory is calculated by dividing the plane in 24 equally spaced sectors. From the calculated histogram, a distinctive signature is associated to each fault trajectory in the dq-plane. Single and double faults in the power semi-conductors are analysed that all provide linearly independent signatures for fault isolation. The proposed isolation methodology is independent of the load torque (system disturbance), supply frequency and only requires the information of the stator currents. Furthermore, since the isolation stage is focused on the angle of the current trajectories in the dq-plane, open- and closed-loop configurations of a variable speed drive can be simultaneously handled. Experimental results with a test bench of 3/4 HP induction motor under single and concurrent faults validated the proposed methodology.

关键词： fault diagnosis Fourier series induction motor drives invertors machine testing pattern recognition power semiconductor devices stators variable speed drives open-switch fault diagnosis variable speed drive pattern recognition open-switch fault isolation open-switch fault detection voltage source inverter stator current measurement post-fault trajectory histogram Fourier series dq-plane dq-frame power semiconductor device isolation methodology load torque supply frequency closed-loop configuration open-loop configuration induction motor machine testing

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A new multicolumn, open-loop process for center-cut separation by solvent-gradient chromatography

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JOURNAL OF CHROMATOGRAPHY A 2010年第52期1217卷 8257-8269页

作者： Silva, Ricardo J. S. Rodrigues, Rui C. R. Osuna-Sanchez, Hector Bailly, Michel Valery, Eric Mota, Jose P. B. Univ Nova Lisboa Fac Ciencias & Tecnol Dept Quim Requimte CQFB P-2829516 Caparica Portugal NOVASEP Proc F-54340 Pompey France ENSIC INPL Lab React & Genie Procedes F-54001 Nancy France

A comprehensive description of a new process-the GSSR (Gradient with Steady State Recycle) process-for center-cut separation by solvent-gradient chromatography is provided, highlighting its versatility, flexibility, and ease of operation. The GSSR process is particularly suited for ternary separation of bioproducts: it provides three main fractions or cuts, with a target product contained in the intermediate fraction. The process comprises a multicolumn. open-loop system, with cyclic steady state operation. that simulates a solvent gradient moving countercurrently with respect to the solid phase. However, the feed is always injected into the same column and the product always collected from the same column as in a batch process;moreover, both steps occur only once per cycle. The GSSR process was experimentally validated in a pilot unit, using the purification of a crude peptide mixture by reversed phase as a proof of concept;the crude mixture is roughly 50% pure and some of its impurities have isocratic retention times very close to that of the target peptide. Experimental results are reported in terms of cyclic steady-state profiles and process performance indicators, which include product purity and yield. A simplified model-based approach, which uses only a few key components of the crude mixture, is employed to assist in the explanation of the process operation. By dynamically adjusting the switching interval while the process is running, to correctly position the composition profile with respect to the outlet ports, pure product satisfying the target specifications-98% purity and 95% recovery-was obtained under stable operation in the pilot unit. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Center-cut separation Solvent gradient Multi-column chromatography open-loop configuration Biochromatography

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Multiobjective planning of open-loop MV distribution networks using ComGIS network analysis and MOGA

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ELECTRIC POWER SYSTEMS RESEARCH 2009年第2期79卷 390-398页

作者： Kong, Tao Cheng, Haozhong Hu, Zechun Yao, Liangzhong Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China AREVA T&D Technol Ctr Stafford ST17 4LX England

An advanced method for optimal planning of open-loop medium voltage (MV) distribution network is proposed in this paper. The multiobjective planning model of open-loop MV distribution network is formulated, and an outage cost calculating method applicable for open-loop MV distribution networks is proposed. To solve the optimization problem, a special Multiobjective Genetic Algorithm (MOGA) is designed based on the network dataset built by Component Geographical Information Systems (ComGIS). The network analysis function of the ComGIS is embedded in the overall optimization process of the MOGA to find single-loop optimal paths. Crossover and mutation operator are designed according to characteristics of the coding. The evolutionary orientation is directed by the fitness function based on the Pareto order of individuals. The Pareto Optimal Set (POS) including several candidate planning schemes is obtained through the MOGA, from which the recommended scheme is selected. The practicability of the method is tested by its application to a real distribution system. (C) 2008 Elsevier B.V. All rights reserved.

关键词： Medium-voltage distribution network open-loop configuration Multiobjective Genetic Algorithm Component Geographical Information Systems Distribution network planning

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Chiral separation by two-column, semi-continuous, open-loop simulated moving-bed chromatography

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JOURNAL OF CHROMATOGRAPHY A 2010年第33期1217卷 5407-5419页

作者： Araujo, Joao M. M. Rodrigues, Rui C. R. Eusebio, Mario F. J. Mota, Jose P. B. Univ Nova Lisboa Fac Ciencias & Tecnol Dept Quim Requimte CQFB P-2829516 Caparica Portugal

A two-column version of a multicolumn, semi-continuous, open-loop chromatograph for chiral separation is presented and validated experimentally. The heart of the process is a flexible node design and cyclic flow-rate modulation that succeed at keeping the mass-transfer zone inside the system without resorting to any recycling technique. One advantage of this streamlined design is the simplicity of its physical realization: regardless of the number of columns, it only requires two pumps to supply feed and desorbent into the system, while the flow rates of liquid withdrawn from the system are controlled by material balance using simple two-way valves. A rigorous model-based optimization approach is employed in the optimal cycle design to generate a solution that is physically realizable in the experimental apparatus. The optimized scheme for two-column operation supplies fresh feed into the system where the composition of the circulating fluid is closest to that of the feedstock fluid, and recovers the purified products, extract and raffinate, alternately at the downstream end of the unit while desorbent is supplied into the upstream end of the system. The feasibility and effectiveness of the two-column process are verified experimentally on the separation of reboxetine racemate, a norepinephrine re-uptake inhibitor, under overloaded conditions. Our set-up employs an automated on-line enantiomeric analysis system, comprising an analytical HPLC set-up with two UV detectors to monitor the composition profile at the downstream end of one of the columns;this monitoring system does not use a polarimeter. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Simulated moving bed open-loop configuration Two-column process Chiral separation

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Ammonium removal by liquid-liquid membrane contactors in water purification process for hydrogen production

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DESALINATION AND WATER TREATMENT 2015年第13期56卷 3607-3616页

作者： Licon, Edxon Reig, Monica Villanova, Pilar Valderrama, Cesar Gibert, Oriol Luis Cortina, Jose UPC Barcelona TECH Dept Chem Engn Barcelona 08028 Spain CETAQUA Cornella De Llobregat 08940 Spain

In this work, a liquid-liquid membrane contactor (LLMC) was evaluated to remove ammonia traces from water used for hydrogen production by electrolysis. Three operational parameters were evaluated: the feed flow rate, the initial ammonia concentration in the water stream, and the pH of solution. Synthetic aqueous solutions with ammonium concentration of 5-25mgL(-1) and a sulfuric acid solution (pH 2) were supplied to the LLMC in countercurrent and open-loop configuration with flow rates between 2.72x10(-6) and 22.6x10(-6)m(3)s(-1) and the pH values of the solution with ammonium between 8 and 11. A 2D numerical model was developed considering advection-diffusion equation inside a single fiber of the lumen with fully developed laminar flow and liquid-gas equilibrium in the membrane-solution interface. Predictions of the model were then validated against experimental data, which were found to be in good agreement. According to both, experimental data and numerical predictions, the hollow-fiber membrane contactor technology is a suitable alternative to remove ammonium from water and to feed the membrane distillation unit in order to fulfill water quality requirements for electrolysis-based hydrogen production.

关键词： Ammonium removal Membrane contactors open-loop configuration Numerical simulation

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Interfacing in silico and in vitro neuronal networks 37

Interfacing <i>in silico</i> and <i>in vitro</i> neuronal ne...

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37th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC)

作者： Bruzzone, Arianna Pasquale, Valentina Nowak, Przemyslaw Tessadori, Jacopo Massobrio, Paolo Chiappalone, Michela IIT Dept Neurosci & Brain Technol I-16163 Genoa Italy Univ Genoa Dept Informat Bioengn Robot & Syst Engn DIBRIS I-16145 Genoa Italy

ISBN: (纸本)9781424492701

In this study, an in vitro cortical culture was stimulated according to the activity exhibited by its in silico counterpart. We connected the latter, an artificial spiking neural network (SNN), to the former, a biological network (BNN), via an open-loop (i.e. unidirectional) configuration, with the ultimate goal of establishing a closed-loop bidirectional connection in future studies. We detected network bursts in the SNN and utilized them as triggers for stimulus delivery to the BNN. We analyzed evoked BNN responses to evaluate whether the BNN activity was entrained by the SNN by correlating stimuli and BNN evoked network burst rates at different timescales. We found that this correlation was nearly constant at all timescales, but its magnitude depended on the efficacy of the stimulation source in entraining BNN activity.

关键词： closed loop systems electroencephalography medical signal processing microelectrodes neural nets open loop systems BNN activity BNN evoked network burst rates SNN artificial spiking neural network biological network closed-loop bidirectional connection evoked BNN responses in silico neuronal networks in vitro cortical culture in vitro neuronal networks open-loop configuration stimulation source stimulus delivery Biological neural networks Correlation Electrical stimulation Firing In vitro Neurons Neuroscience

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Multiobjective planning of open-loop MV distribution networks using ComGIS network analysis and MOGA

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3rd International Conference on Electric Utility Deregulation, Restructuring and Power Technologies

作者： Kong Tao Cheng Haozhong Hu Zechun Wang Chun Huang Wei Chen Chunqin Gao Yubo Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China

ISBN: (纸本)9787564112493

In this paper, an advanced method for the planning of open-loop medium voltage (MV) distribution network is proposed. The multiobjective planning model is constructed, and a special multiobjective genetic algorithm (MOGA) is designed based on the network dataset built by Component geographical information systems (ComGIS). The network analysis function of the ComGIS is embedded in the overall optimization process to find single-loop optimal paths. Crossover and mutation operator are designed according to characteristics of the coding. The evolutionary orientation is directed by the fitness function based on Pareto order of individuals. The Pareto optimal set (POS) including several candidate planning schemes is gotten through MOGA, from which the recommended scheme is selected. The method has been applied to real life power distribution networks, showing its potential in practical applications.

关键词： component geographical information systems distribution network planning medium-voltage distribution network multiobjective genetic algorithm network analysis open-loop configuration

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PERFORMANCE OF A NEW DECODING METHOD USED IN open-loop ALL-OPTICAL CHAOTIC COMMUNICATION SYSTEM

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Journal of Electronics(China) 2011年第1期28卷 126-133页

作者： Liu Huijie Feng Jiuchao School of Electronic and Information Engineering South China University of Technology Guanqzhou 510641 China Department of Electronic Engineering Dongguan University of Technology Dongguan 523808 China

A new decoding method with decoder is used in open-loop all-optical chaotic communication system under strong injection *** performance of the new decoding method is numerically investigated by comparing it with the common decoding method without *** new decoding method,two cases are analyzed,including whether or not the output of the decoder is adjusted by its input to *** results indicate the decoding quality can be improved by adjusting for the new decoding ***,the injection strength of decoder can be restricted in a certain *** adjusted new decoding method with decoder can achieve better decoding quality than decoding method without decoder when the bit rate of message is under 5 Gb/***,a stronger injection for receiver is ***,the new decoding method can broaden the range of injection strength acceptable for good decoding *** message encryption techniques are tested,and the result is similar to that of the common decoding method,indicative of the fact that the message encoded by using Chaotic Modulation(CM) can be best recovered by the new decoding method owning to the essence of this encryption technique.

关键词： Chaotic communication Decoding performance open-loop configuration Semiconductor lasers

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Dual-Channel Chaos Laser Communication System Based on Fiber Link with Dispersion Compensation Scheme

Dual-Channel Chaos Laser Communication System Based on Fiber...

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22nd Wireless and Optical Communications Conference (WOCC)

作者： Liu, Hui-jie Ren, Bin Feng, Jiu-chao Dongguan Univ Technol Sch Elect Engn Dongguan Peoples R China S China Univ Technol Sch Elect & Informat Engn Guangzhou Guangdong Peoples R China

ISBN: (纸本)9781467356978;9781467356992

A model of dual-channel chaos laser communication system based on fiber transmission is proposed in this paper. The practical open-loop configuration at strong injection condition and the excellent symmetrical dispersion compensation scheme are applied in this model. The chaotic modulation (CM) and chaotic shift keying (CSK) methods are used to encrypt the message. The communication performances of both channels are evaluated by the decoding Q factor. And, further, the influences of injection power, encryption method and bit-rate of message on the performances of both channels are researched. The simulation result indicated that the optimal injection power will decrease when two channels are multiplexed compared with the single-channel case in order to balance between restraining the adjacent interfere and keeping optical field enough strong. For each channel, CSK method is better for a low bit-rate message and CM method is better for a high bit-rate. However, for the case of dual-channel communication, one channel can achieve the optimal performance at best whatever the encryption method are. It requires that different encryption methods are applied in both channels, and the optimal communication performance can be achieved for the low-speed channel encrypted by CSK method and the high-speed channel encrypted by CM.

关键词： chaotic communication dual-channel dispersion compensation semiconductor lasers open-loop configuration

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