The effects of random long-range connections （shortcuts） on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is ...The effects of random long-range connections （shortcuts） on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is found that, on one hand, the system can achieve the transition of neural firing patterns from the fewer-period state to the multi-period one, when the number of the added shortcuts in the neural network is greater than a threshold value, indicating the occurrence of in-transition of neural firing patterns. On the other hand, for a stronger coupling strength, we can also find the similar but reverse results by adding some proper random connections. In addition, the influences of system size and coupling strength on such transition behavior, as well as the internality between the transition degree of firing patterns and its critical characteristics for different external stimulation current, are also discussed.展开更多
A hyperchaos-based watermarking algorithm is developed in the wavelet domain for images.The algorithm is based on discrete wavelet transform and combines the communication model with side information.We utilize a suit...A hyperchaos-based watermarking algorithm is developed in the wavelet domain for images.The algorithm is based on discrete wavelet transform and combines the communication model with side information.We utilize a suitable scale factor to scale host image,then construct cosets for embedding digital watermarking according to scale version of the host image.Our scheme makes a tradeoff between imperceptibility and robustness,and achieves security.The extraction algorithm is a blind detection algorithm which retrieves the watermark without the original host image.In addition,we propose a new method for watermark encryption with hyperchaotic sequence.This method overcomes the drawback of small key space of chaotic sequence and improves the watermark security.Simulation results indicate that the algorithm is a well-balanced watermarking method that offers good robustness and imperceptibility.展开更多
Cracking gas compressor is usually a centrifugal compressor. The information on the performance of a centrifugal compressor under all conditions is not available, which restricts the operation optimization for compres...Cracking gas compressor is usually a centrifugal compressor. The information on the performance of a centrifugal compressor under all conditions is not available, which restricts the operation optimization for compressor. To solve this problem, two back propagation (BP) neural networks were introduced to model the performance of a compressor by using the data provided by manufacturer. The input data of the model under other conditions should be corrected according to the similarity theory. The method was used to optimize the system of a cracking gas compressor by embedding the compressor performance model into the ASPEN PLUS model of compressor. The result shows that it is an effective method to optimize the compressor system.展开更多
The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce...The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.展开更多
In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evo...In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evolution equations. To illustrate the effectiveness of our method, we take the （2＋ 1）-dimensional stochastic dispersive long wave system as an example. We not only have obtained some known solutions, but also have constructed some new rational formal stochastic Jacobi elliptic function solutions.展开更多
With the aid of the spectnnn techique, a new concept named-α-stabilizability （0≤α≤1） is intnxhged and its suffident and necessary canditions are also prvposed. Especially, it is identical with the asymptotically...With the aid of the spectnnn techique, a new concept named-α-stabilizability （0≤α≤1） is intnxhged and its suffident and necessary canditions are also prvposed. Especially, it is identical with the asymptotically mean square stabilizability when α = 1. As an application, the suboptimal state feedback H2/H∞ controller that satisfies the additional Spectrum canstmint via solving a convex optimization problem is delt with.展开更多
The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic prob...The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.展开更多
This paper mainly discusses stabilizatbility, exact observability and exact detectability of discrete stochastic systems with both static and control dependent noise via the spectrum technique. The authors put forward...This paper mainly discusses stabilizatbility, exact observability and exact detectability of discrete stochastic systems with both static and control dependent noise via the spectrum technique. The authors put forward a definition of the spectrum and give some theorems based on the spectrum. Then the relation between discrete generalized Lyapunov equation and discrete generalized algebraic Riccati equation is also analyzed.展开更多
Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliabilit...Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliability criterion model, is established. ‘Next happen event’ is taken as impulse principle of simulator clock to determine the sequence of random event occurrence dynamically. The results show this method is feasible.展开更多
For the discrete-time system which is subjected to uncoupled actuator faults and sensor faults simultaneously,a robust fault diagnosis method based on a proportional integral observer (PIO) is presented.The proposed P...For the discrete-time system which is subjected to uncoupled actuator faults and sensor faults simultaneously,a robust fault diagnosis method based on a proportional integral observer (PIO) is presented.The proposed PIO uses an additionally introduced integral term of the output errors to obtain the estimationof actuator faults. Besides, the sensor faults are regarded as the augment states so that the PIO cantrace them. Moreover, the convergence of the PIO is proved. A variable speed wind turbine(VWT) exampleis given to demonstrate the fast convergence and diagnosis precision of the proposed PIO.展开更多
The concept of an integrated "lab on a chip" has long been a goal for the micro-electro-mechanical-systems(MEMS) community.This would entail the integration of not only the sampling and analysis of various f...The concept of an integrated "lab on a chip" has long been a goal for the micro-electro-mechanical-systems(MEMS) community.This would entail the integration of not only the sampling and analysis of various functions,but also the ability to transmit this information off the chip to a central repository.This paper describes the initial steps in the fabrication of a "lab on a chip" which would continually analyze blood sampled via microneedles using techniques such as nano plasmonics,specifically,concentrations of glucose.The analysis could then be transmitted off the chip using digital signal processing.This paper describes the analysis and optimization of the microneedle shape and size and the fabrication of the resulting needles in silicon using deep reactive ion etching(DRIE).The paper also describes the opportunities for fabrication of such needles in alternative materials and describes the issues that still have to be overcome before such an integrated device is realized.展开更多
The author introduced particle swarm optimization as a new method for power transmission network expansion planning. A new discrete method for particle swarm optimization was developed,which is suitable for power tran...The author introduced particle swarm optimization as a new method for power transmission network expansion planning. A new discrete method for particle swarm optimization was developed,which is suitable for power transmission network expansion planning, and requires less computer s memory.The optimization fitness function construction, parameter selection, convergence judgement, and their characters were analyzod.Numerical simulation demonstrated the effectiveness and correctness or the method. This paper provides an academic and practical basis of particle swarm optimization in application of transmission network expansion planning for further investigation.展开更多
A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary functi...A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.展开更多
This paper describes target detection improvement in a distance measurement system using two rotatable cameras for floating production, storage and offloading （FPSO） facilities. The authors have developed a distance...This paper describes target detection improvement in a distance measurement system using two rotatable cameras for floating production, storage and offloading （FPSO） facilities. The authors have developed a distance measurement system that consists of two rotatable cameras on a ship and a target on a wharf for the automatic berthing of ships. This system measures a distance by detecting and tracking the target on the wharf using the two rotatable cameras on the ship. Our goal is to apply this distance measurement system to an automatic relative positioning system for a ship at an FPSO facility. In this application, the shape of the target in the images captured by the cameras is deformed by their relative positions and attitudes, which increases the measurement errors. To solve this problem, we propose a target detection method that improves the target deformations. The proposed target detection method is able to detect the deformed targets using a target database that is created by image conversion with the perspective projection of a reference target. By using the proposed target detection method, the distance measurement error is decreased. Experimental results on a miniature scale and in an indoor environment confirmed that the measurement error of the relative distance is decreased by using the proposed target detection method.展开更多
An evaporator-condenser-separated mechanical vapor compression (MVC) system was presented. The better effect of descaling and antiscaling was obtained by the new system. This study focused on the method of thermodynam...An evaporator-condenser-separated mechanical vapor compression (MVC) system was presented. The better effect of descaling and antiscaling was obtained by the new system. This study focused on the method of thermodynamic analysis, and the energy and exergy flow diagrams were established by using the first and second law of thermodynamics analysis. The results show that the energy utilization rate is very high and the specific power consumption is low. Exergy analysis indicates that the exergy efficiency is low, and the largest exergy loss occurs within the evaporator-condenser and the compressor.展开更多
文摘The effects of random long-range connections （shortcuts） on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is found that, on one hand, the system can achieve the transition of neural firing patterns from the fewer-period state to the multi-period one, when the number of the added shortcuts in the neural network is greater than a threshold value, indicating the occurrence of in-transition of neural firing patterns. On the other hand, for a stronger coupling strength, we can also find the similar but reverse results by adding some proper random connections. In addition, the influences of system size and coupling strength on such transition behavior, as well as the internality between the transition degree of firing patterns and its critical characteristics for different external stimulation current, are also discussed.
基金Supported by National Natural Science Foundation of China(60574036) ,the Specialized Research Fund for the Doctoral Pro-gramof Higher Education of China (20050055013) ,and the program for New Century Excellent Talents in University of China(NCET) .
文摘A hyperchaos-based watermarking algorithm is developed in the wavelet domain for images.The algorithm is based on discrete wavelet transform and combines the communication model with side information.We utilize a suitable scale factor to scale host image,then construct cosets for embedding digital watermarking according to scale version of the host image.Our scheme makes a tradeoff between imperceptibility and robustness,and achieves security.The extraction algorithm is a blind detection algorithm which retrieves the watermark without the original host image.In addition,we propose a new method for watermark encryption with hyperchaotic sequence.This method overcomes the drawback of small key space of chaotic sequence and improves the watermark security.Simulation results indicate that the algorithm is a well-balanced watermarking method that offers good robustness and imperceptibility.
基金Supported by the National Natural Science Foundation of China (20976048, 21176072)the Fundamental Research Funds for the Central Universities
文摘Cracking gas compressor is usually a centrifugal compressor. The information on the performance of a centrifugal compressor under all conditions is not available, which restricts the operation optimization for compressor. To solve this problem, two back propagation (BP) neural networks were introduced to model the performance of a compressor by using the data provided by manufacturer. The input data of the model under other conditions should be corrected according to the similarity theory. The method was used to optimize the system of a cracking gas compressor by embedding the compressor performance model into the ASPEN PLUS model of compressor. The result shows that it is an effective method to optimize the compressor system.
基金Project(50975083) supported by the National Natural Science Foundation of ChinaProject(61075001) supported by China State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyProject(201-IV-068) supported by the Fundamental Research Funds for the Central Universities,China
文摘The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.
基金The project partially supported by the State Key Basic Research Program of China under Grant No. 2004CB318000
文摘In this work, by means of a generalized method and symbolic computation, we extend the Jacobi elliptic function rational expansion method to uniformly construct a series of stochastic wave solutions for stochastic evolution equations. To illustrate the effectiveness of our method, we take the （2＋ 1）-dimensional stochastic dispersive long wave system as an example. We not only have obtained some known solutions, but also have constructed some new rational formal stochastic Jacobi elliptic function solutions.
基金supported by the research project of “SDUST Spring Bud”(Grant No.2008AZZ090)the National Natural Science Foundation of China(Grant No.60874032)
文摘With the aid of the spectnnn techique, a new concept named-α-stabilizability （0≤α≤1） is intnxhged and its suffident and necessary canditions are also prvposed. Especially, it is identical with the asymptotically mean square stabilizability when α = 1. As an application, the suboptimal state feedback H2/H∞ controller that satisfies the additional Spectrum canstmint via solving a convex optimization problem is delt with.
文摘The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.
文摘This paper mainly discusses stabilizatbility, exact observability and exact detectability of discrete stochastic systems with both static and control dependent noise via the spectrum technique. The authors put forward a definition of the spectrum and give some theorems based on the spectrum. Then the relation between discrete generalized Lyapunov equation and discrete generalized algebraic Riccati equation is also analyzed.
基金SupportedbyNationalNatureScienceFoundation No .5 0 1770 17
文摘Discrete-event system simulation technology is used to analyze distribution system reliability in this paper. A simulation model, including entity state models, system state models, state transition models, reliability criterion model, is established. ‘Next happen event’ is taken as impulse principle of simulator clock to determine the sequence of random event occurrence dynamically. The results show this method is feasible.
基金Supported by the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (No. 2007BAF10B00).
文摘For the discrete-time system which is subjected to uncoupled actuator faults and sensor faults simultaneously,a robust fault diagnosis method based on a proportional integral observer (PIO) is presented.The proposed PIO uses an additionally introduced integral term of the output errors to obtain the estimationof actuator faults. Besides, the sensor faults are regarded as the augment states so that the PIO cantrace them. Moreover, the convergence of the PIO is proved. A variable speed wind turbine(VWT) exampleis given to demonstrate the fast convergence and diagnosis precision of the proposed PIO.
文摘The concept of an integrated "lab on a chip" has long been a goal for the micro-electro-mechanical-systems(MEMS) community.This would entail the integration of not only the sampling and analysis of various functions,but also the ability to transmit this information off the chip to a central repository.This paper describes the initial steps in the fabrication of a "lab on a chip" which would continually analyze blood sampled via microneedles using techniques such as nano plasmonics,specifically,concentrations of glucose.The analysis could then be transmitted off the chip using digital signal processing.This paper describes the analysis and optimization of the microneedle shape and size and the fabrication of the resulting needles in silicon using deep reactive ion etching(DRIE).The paper also describes the opportunities for fabrication of such needles in alternative materials and describes the issues that still have to be overcome before such an integrated device is realized.
基金Supported by National Natural Science Foundation of China (50177017)Important science and technology research project of Shanghai China (041612012)National Power Grid Company subsidized Research SGZL[2004]151.
文摘The author introduced particle swarm optimization as a new method for power transmission network expansion planning. A new discrete method for particle swarm optimization was developed,which is suitable for power transmission network expansion planning, and requires less computer s memory.The optimization fitness function construction, parameter selection, convergence judgement, and their characters were analyzod.Numerical simulation demonstrated the effectiveness and correctness or the method. This paper provides an academic and practical basis of particle swarm optimization in application of transmission network expansion planning for further investigation.
文摘A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV （autonomons underwater vehicle） and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES （time discrete event system）. After taking into account the time problem, it is a useful method to control mating by sinmlation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.
文摘This paper describes target detection improvement in a distance measurement system using two rotatable cameras for floating production, storage and offloading （FPSO） facilities. The authors have developed a distance measurement system that consists of two rotatable cameras on a ship and a target on a wharf for the automatic berthing of ships. This system measures a distance by detecting and tracking the target on the wharf using the two rotatable cameras on the ship. Our goal is to apply this distance measurement system to an automatic relative positioning system for a ship at an FPSO facility. In this application, the shape of the target in the images captured by the cameras is deformed by their relative positions and attitudes, which increases the measurement errors. To solve this problem, we propose a target detection method that improves the target deformations. The proposed target detection method is able to detect the deformed targets using a target database that is created by image conversion with the perspective projection of a reference target. By using the proposed target detection method, the distance measurement error is decreased. Experimental results on a miniature scale and in an indoor environment confirmed that the measurement error of the relative distance is decreased by using the proposed target detection method.
文摘An evaporator-condenser-separated mechanical vapor compression (MVC) system was presented. The better effect of descaling and antiscaling was obtained by the new system. This study focused on the method of thermodynamic analysis, and the energy and exergy flow diagrams were established by using the first and second law of thermodynamics analysis. The results show that the energy utilization rate is very high and the specific power consumption is low. Exergy analysis indicates that the exergy efficiency is low, and the largest exergy loss occurs within the evaporator-condenser and the compressor.
