Based on a modified Lorenz system, a relatively simple four-dimensional continuous autonomous hyperchaotic system is proposed by introducing a state feedback controller. The system consists of four coupled first-order...Based on a modified Lorenz system, a relatively simple four-dimensional continuous autonomous hyperchaotic system is proposed by introducing a state feedback controller. The system consists of four coupled first-order ordinary differential equations with three nonlinear cross-product terms. Some dynamical properties of this hyperchaotic system, including equlibria, stability, Lyapunov exponent spectrum and bifurcation, are analysed in detail. Moreover, an electronic circuit diagram is designed for demonstrating the existence of the hyperchaos, and verifying computer simulation results.展开更多
Focusing on the linearity shortcoming on a bipolar low noise amplifier(LNA),a new 6 ~14GHz four stage SiGe HBT LNA is proposed.This amplifier adopts a method of gain allocation on multiple stages to avoid the limitati...Focusing on the linearity shortcoming on a bipolar low noise amplifier(LNA),a new 6 ~14GHz four stage SiGe HBT LNA is proposed.This amplifier adopts a method of gain allocation on multiple stages to avoid the limitation on linearity especially with the addition of negative gain on the third stage.To realize gain flatness,extra zero is introduced to compensate the gain roll-off formed by pole,and local shunt-shunt negative feedback is used to widen the bandwidth as well as optimize circuit' s noise.Simulated results have shown that in 6 ~14GHz,this circuit achieves noise figure(NF) less than 3dB,gain of 17.8dB(+0.2dB),input and output reflection parameters of less than- 10 dB,and the K factor is above 1.15.展开更多
An experimental study and theoretical analysis were carried out to explore the ground-borne vibration generated by elevated high-speed railway in rock strata.Taking a typical rail line constructed on rock area in Chin...An experimental study and theoretical analysis were carried out to explore the ground-borne vibration generated by elevated high-speed railway in rock strata.Taking a typical rail line constructed on rock area in China as the research object,a set of field tests was performed on Rizhao-Lankao High-Speed Railway,the bridge and ground vibrations were measured as trains passed at 330−340 km/h,then the transferring law and spatial distribution under individual frequencies were investigated.The experiment results indicate that the bridge frequency spectrum exhibited relatively high-frequency vibration peaks caused by short-wavelength irregularity;ground vibration farther than 30 m away can be amplified with a higher frequency and numerous components.Furthermore,the wave propagation equation of a stratified rock strata was established based on direct-stiffness method to explore the vibration attenuation rules via frequency-domain analysis.It is found that the rock area has a weaker correlation between vibration transmissibility and frequency,thicker and harder rock strata loss their vibration attenuation capacity.It can be concluded that the high-speed railways induced vibration on rock strata shows a wide frequency band and large amplitude,the design of reducing vibration aimed at specific frequency is important according to next more detailed numerical study.展开更多
To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological s...To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological structure.Complex dynamical behaviors of the systems including chaos and periodic orbits were verified by numerical simulations,Lyapunov exponents and bifurcation diagrams.Interestingly,the three systems were integrated in a common circuit,and their dynamical behaviors were easily observed by adjusting regulable resistors R28,R14 and R17,respectively,and the relations between the variable resistor and the system parameter were deduced.The circuit experiment results agree well with the simulation results.Finally,a secure communication scheme based on chaos shift keying(CSK) was presented,which lays an experiment foundation for chaotic digital secure communication.展开更多
New methodologies for l-Bit XOR-XNOR full- adder circuits are proposed to improve the speed and power as these circuits are basic building blocks for ALU circuit implementation. This paper presents comparative study o...New methodologies for l-Bit XOR-XNOR full- adder circuits are proposed to improve the speed and power as these circuits are basic building blocks for ALU circuit implementation. This paper presents comparative study of high-speed, low-power and low voltage full adder circuits. Simulation results illustrate the superiority of the proposed adder circuit against the conventional complementary metal-oxide-semiconductor （CMOS）, complementary pass-transistor logic （CPL）, TG, and Hybrid adder circuits in terms of delay, power and power delay product （PDP）. Simulation results reveal that the proposed circuit exhibits lower PDP and is more power efficient and faster when compared with the best available 1-bit full adder circuits. The design is implemented on UMC 0.18 μm process models in Cadence Virtuoso Schematic Composer at 1.8 V single ended supply voltage and simulations are carried out on Spectre S.展开更多
This paper investigates the synchronization and circuit implementation of a new hyperchaotic Lorenz system. This system is generated by controlling a generalized Lorenz system to hyperchaotic by introducing a linear s...This paper investigates the synchronization and circuit implementation of a new hyperchaotic Lorenz system. This system is generated by controlling a generalized Lorenz system to hyperchaotic by introducing a linear state feedback controller to its scored equation. Global synchronization of the new hyperchaotic systems can be achieved by unidirectonally linear coupled approach, which is illustrated by both numerical simulations and electronic circuit experiments.展开更多
To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse samplin...To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse sampling for an ultrasonic signal pulse is presented.Differences between the pulse and the coded ultrasonic signal are analyzed,and a response mathematical model of the coded ultrasonic signal is established.A time-domain transform algorithm,called the high-order moment method,is applied to obtain a pulse stream signal to assist BFC ultrasonic signal sparse sampling.A sampling of the output signal with a uniform interval is then performed after modulating the pulse stream signal by a sampling kernel.FRI-based sparse sampling is performed using a self-made circuit on an aluminum alloy sample.Experimental results show that the sampling rate reduces to 0.5 MHz,which is at least 12.8 MHz in the Nyquist sampling mode.The echo peak amplitude and the time of flight are estimated from the sparse sampling data with maximum errors of 9.324%and 0.031%,respectively.This research can provide a theoretical basis and practical application reference for reducing the sampling rate and data volume in coded ultrasonic testing.展开更多
This paper presents a word alignment circuit for high speed SerDes system.By using pipeline structure and circuit optimization techniques,the speed of the aligner is increased,and its performance is improved further t...This paper presents a word alignment circuit for high speed SerDes system.By using pipeline structure and circuit optimization techniques,the speed of the aligner is increased,and its performance is improved further through adopting the full custom design method.The proposed word aligner has fabricated in 0.18μm CMOS technology with total area of 1.075 ×0.775mm^2￣ including I/O pad.Measurement results show that this circuit achieves the maximum data rate of 14.5Gb/s,while consuming a total power of 34.9mW from a 1.8V supply.展开更多
基金Project supported by the Natural Science Foundation of Zhejiang Province, China （Grant No Y105175） and the Science investigation Foundation of Hangzhou Dianzi University, China （Grant No KYS051505010）.
文摘Based on a modified Lorenz system, a relatively simple four-dimensional continuous autonomous hyperchaotic system is proposed by introducing a state feedback controller. The system consists of four coupled first-order ordinary differential equations with three nonlinear cross-product terms. Some dynamical properties of this hyperchaotic system, including equlibria, stability, Lyapunov exponent spectrum and bifurcation, are analysed in detail. Moreover, an electronic circuit diagram is designed for demonstrating the existence of the hyperchaos, and verifying computer simulation results.
基金Supported by the National Natural Science Foundation of China(No.61076101,61204092,61306033)
文摘Focusing on the linearity shortcoming on a bipolar low noise amplifier(LNA),a new 6 ~14GHz four stage SiGe HBT LNA is proposed.This amplifier adopts a method of gain allocation on multiple stages to avoid the limitation on linearity especially with the addition of negative gain on the third stage.To realize gain flatness,extra zero is introduced to compensate the gain roll-off formed by pole,and local shunt-shunt negative feedback is used to widen the bandwidth as well as optimize circuit' s noise.Simulated results have shown that in 6 ~14GHz,this circuit achieves noise figure(NF) less than 3dB,gain of 17.8dB(+0.2dB),input and output reflection parameters of less than- 10 dB,and the K factor is above 1.15.
基金Project(2016YFE0205200)supported by the National Key Research and Development Program of ChinaProjects(U1734207,51978585)supported by the National Natural Science Foundation of China。
文摘An experimental study and theoretical analysis were carried out to explore the ground-borne vibration generated by elevated high-speed railway in rock strata.Taking a typical rail line constructed on rock area in China as the research object,a set of field tests was performed on Rizhao-Lankao High-Speed Railway,the bridge and ground vibrations were measured as trains passed at 330−340 km/h,then the transferring law and spatial distribution under individual frequencies were investigated.The experiment results indicate that the bridge frequency spectrum exhibited relatively high-frequency vibration peaks caused by short-wavelength irregularity;ground vibration farther than 30 m away can be amplified with a higher frequency and numerous components.Furthermore,the wave propagation equation of a stratified rock strata was established based on direct-stiffness method to explore the vibration attenuation rules via frequency-domain analysis.It is found that the rock area has a weaker correlation between vibration transmissibility and frequency,thicker and harder rock strata loss their vibration attenuation capacity.It can be concluded that the high-speed railways induced vibration on rock strata shows a wide frequency band and large amplitude,the design of reducing vibration aimed at specific frequency is important according to next more detailed numerical study.
基金Projects(611061006,61073187) supported by the National Nature Science Foundation of China
文摘To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological structure.Complex dynamical behaviors of the systems including chaos and periodic orbits were verified by numerical simulations,Lyapunov exponents and bifurcation diagrams.Interestingly,the three systems were integrated in a common circuit,and their dynamical behaviors were easily observed by adjusting regulable resistors R28,R14 and R17,respectively,and the relations between the variable resistor and the system parameter were deduced.The circuit experiment results agree well with the simulation results.Finally,a secure communication scheme based on chaos shift keying(CSK) was presented,which lays an experiment foundation for chaotic digital secure communication.
文摘New methodologies for l-Bit XOR-XNOR full- adder circuits are proposed to improve the speed and power as these circuits are basic building blocks for ALU circuit implementation. This paper presents comparative study of high-speed, low-power and low voltage full adder circuits. Simulation results illustrate the superiority of the proposed adder circuit against the conventional complementary metal-oxide-semiconductor （CMOS）, complementary pass-transistor logic （CPL）, TG, and Hybrid adder circuits in terms of delay, power and power delay product （PDP）. Simulation results reveal that the proposed circuit exhibits lower PDP and is more power efficient and faster when compared with the best available 1-bit full adder circuits. The design is implemented on UMC 0.18 μm process models in Cadence Virtuoso Schematic Composer at 1.8 V single ended supply voltage and simulations are carried out on Spectre S.
基金upported by National Natural Science Foundation of China(Grant No.60672085)“Taishan Scholarship”Construction Engineering
文摘This paper investigates the synchronization and circuit implementation of a new hyperchaotic Lorenz system. This system is generated by controlling a generalized Lorenz system to hyperchaotic by introducing a linear state feedback controller to its scored equation. Global synchronization of the new hyperchaotic systems can be achieved by unidirectonally linear coupled approach, which is illustrated by both numerical simulations and electronic circuit experiments.
基金The National Natural Science Foundation of China (No.51375217)。
文摘To achieve sparse sampling on a coded ultrasonic signal,the finite rate of innovation(FRI)sparse sampling technique is proposed on a binary frequency-coded(BFC)ultrasonic signal.A framework of FRI-based sparse sampling for an ultrasonic signal pulse is presented.Differences between the pulse and the coded ultrasonic signal are analyzed,and a response mathematical model of the coded ultrasonic signal is established.A time-domain transform algorithm,called the high-order moment method,is applied to obtain a pulse stream signal to assist BFC ultrasonic signal sparse sampling.A sampling of the output signal with a uniform interval is then performed after modulating the pulse stream signal by a sampling kernel.FRI-based sparse sampling is performed using a self-made circuit on an aluminum alloy sample.Experimental results show that the sampling rate reduces to 0.5 MHz,which is at least 12.8 MHz in the Nyquist sampling mode.The echo peak amplitude and the time of flight are estimated from the sparse sampling data with maximum errors of 9.324%and 0.031%,respectively.This research can provide a theoretical basis and practical application reference for reducing the sampling rate and data volume in coded ultrasonic testing.
基金Supported by the National High Technology Research and Development Programme of China(No.2011AA10305)
文摘This paper presents a word alignment circuit for high speed SerDes system.By using pipeline structure and circuit optimization techniques,the speed of the aligner is increased,and its performance is improved further through adopting the full custom design method.The proposed word aligner has fabricated in 0.18μm CMOS technology with total area of 1.075 ×0.775mm^2￣ including I/O pad.Measurement results show that this circuit achieves the maximum data rate of 14.5Gb/s,while consuming a total power of 34.9mW from a 1.8V supply.
