An ultra-broadband polarization splitter based on graphene layer-filled dual-core photonic crystal fiber （GDC-PCF） that can work in a wavelength range from 1120 nm to 1730 nm is proposed in this paper. Through optim...An ultra-broadband polarization splitter based on graphene layer-filled dual-core photonic crystal fiber （GDC-PCF） that can work in a wavelength range from 1120 nm to 1730 nm is proposed in this paper. Through optimizing fiber configuration, the polarization splitter has an extinction ratio of-56.3 dB at 1.55 μm with a fiber length of 4.8 mm. Compared with the photonic crystal fiber reported splitters, to our knowledge, the GDC-PCF splitter with the extinction ratio below-20 dB has a super wide bandwidth of 610 nm. Due to the excellent splitting characteristics, the GDC-PCF will be used in coherent optical communication systems in a wavelength range from infrared to mid-infraed.展开更多
The research of high-performance polarization controllers is of great significance for expanding the application field of polarization optics. Here, a polarization switch is demonstrated by using a dual-core photonic ...The research of high-performance polarization controllers is of great significance for expanding the application field of polarization optics. Here, a polarization switch is demonstrated by using a dual-core photonic crystal fiber(DCPCF)with four symmetrical air holes, placed above and below each core, filled with magnetic fluid(MF). The switch, which utilizes a magnetic field to change the coupling length ratio of the x and y polarization modes, enables dynamic tuning of the polarization state and extinction ratio. Numerical results show that when the working length is 36.638 mm, the magneto–optical polarization switch can operate in four communication bands, i.e., 1509 nm to 1520 nm, 1544 nm to1556 nm, 1578 nm to 1591 nm, and 1611 nm to 1624 nm. Moreover, the extinction ratio(ER) is greater than 20 d B in the fiber length range of 38.5 mm to 38.7 mm, indicating that the device has a good fault tolerance for the interception of the fiber length.展开更多
This paper theoretically investigates the dependence of leaky mode coupling between inner core fundamental mode and outer core defect mode on phase and loss matching in pure silica dual-core photonic crystal fibres wi...This paper theoretically investigates the dependence of leaky mode coupling between inner core fundamental mode and outer core defect mode on phase and loss matching in pure silica dual-core photonic crystal fibres with the multi-pole method. The complete mode coupling can take place when both the phase and loss matching conditions are satisfied at the avoided anti-crossing wavelength. It shows the influences of cladding structure parameters including the diameters of cladding air holes d1, diameters of outer core holes d2 and hole to hole pitch A on the characteristics of leaky modes coupling. The coupled-mode theory is used to analyse the mode transition characteristics and the complete coupling can be clearly indicated by comparing the real and imaginary parts of propagation constant of the leaky modes.展开更多
With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottl...With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottlenecks in performance enhancement,such as drain-induced barrier lowering,reduced mobility caused by interface scattering,and limited current on/off ratios.展开更多
A new kind of simple and flexible CO2 welding system was developed to carry out waveform control. The system consisted of IGBT inverter, PWM circuit and microprocessor unit （ MPU） , in which the output current of co...A new kind of simple and flexible CO2 welding system was developed to carry out waveform control. The system consisted of IGBT inverter, PWM circuit and microprocessor unit （ MPU） , in which the output current of constant current （CC） power supply could be changed according to transient physical state, and the variable down slope rate control could be used to ensure a stable welding process. The welding experiment results proved the effectiveness of this control approach.展开更多
Virtual memory management is always a very essential issue of the modern microprocessor design. A memory management unit (MMU) is designed to implement a virtual machine for user programs, and provides a management me...Virtual memory management is always a very essential issue of the modern microprocessor design. A memory management unit (MMU) is designed to implement a virtual machine for user programs, and provides a management mechanism between the operating system and user programs. This paper analyzes the tradeoffs considered in the MMU design of Unity 11 CPU of Peking University, and introduces in detail the solution of pure hardware table walking with two level page table organization. The implementation takes care of required operations and high performances needed by modern operating systems and low costs needed by embedded systems. This solution has been silicon proven, and successfully porting the Linux 2.4.17 kernel, the XWindow system, GNOME and most application software onto the Unity platform.展开更多
The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an a...The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.展开更多
This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed...This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed from SPWM-GTR inverter.The whole system is combined by twosubsystems,both of them are 8031 single chip microprocessors.The communication between themis coordinated by the full duplex serial port within the chip and ask-and-answer communicationmanner.The error-corrected means adopted has improved the operation reliability of the system.A series of experimental results on a 3 kW induction motor are given at the end of this paper.展开更多
In this paper the authors present an analysis and the implementation of microprocessor-baseddigital phase-locked loop speed control system for an induction motor which is actuated by aSPWM-GTR inverter.The system is c...In this paper the authors present an analysis and the implementation of microprocessor-baseddigital phase-locked loop speed control system for an induction motor which is actuated by aSPWM-GTR inverter.The system is controlled by a 16-bit single chip microprocessor.A new type of frequency and phase detector is presented in detail,An adaptive method isadopted in speed controller.A three mode control scheme is used.These techniques are very use-ful to the improvement of the dynamic behavior of digital AC motor drive system.Experimental results show that the system is of good stability,high precision and good dynam-ic performance.展开更多
We propose a novel scheme, called on-line cache resizing （OCR）, to dynamically resize the cache and meet the size requirement of each application. At each periodic interval, the scheme gathers the cache hit-miss sta...We propose a novel scheme, called on-line cache resizing （OCR）, to dynamically resize the cache and meet the size requirement of each application. At each periodic interval, the scheme gathers the cache hit-miss statistics at runtime using an extra tag array. These executing statistics serve as inputs to an analytical model of cache energy. The scheme uses energy as a primary metric to dynamically increase/decrease the number of active cache ways for the next interval. The scheme minimizes the active cache size to save energy with minimal performance loss. The simulation with SPEC 2000 benchmarks shows that OCR results in an average of 38.4% energy saving compared with fixed-size caches, with only 2.0% performance loss.展开更多
In the era of Internet of Things, the battery life of edge devices must be extended for sensing connection to the Internet. We aim to reduce the power consumption of the microprocessor embedded in such devices by usin...In the era of Internet of Things, the battery life of edge devices must be extended for sensing connection to the Internet. We aim to reduce the power consumption of the microprocessor embedded in such devices by using a novel dynamically reconfigurable accelerator. Conventional microprocessors consume a large amount of power for memory access, in registers, and for the control of the processor itself rather than computation;this decreases the energy efficiency. Dynamically reconfigurable accelerators reduce such redundant power by computing in parallel on reconfigurable switches and processing element arrays (often consisting of an arithmetic logic unit (ALU) and registers). We propose a novel dynamically reconfigurable accelerator “DYNaSTA” composed of a dynamically reconfigurable data path and static ALU arrays. The static ALU arrays process instructions in parallel without registers and improve energy efficiency. The dynamically reconfigurable data path includes registers and many switches dynamically reconfigured to resolve operand dependencies between instructions mapped on the static ALU array, and forwards appropriate operands to the static ALU array. Therefore, the DYNaSTA accelerator has more flexibility while improving the energy efficiency compared with the conventional dynamically reconfigurable accelerators. We simulated the power consumption of the proposed DYNaSTA accelerator and measured the fabricated chip. As a result, the power consumption was reduced by 69% to 86%, and the energy efficiency improved 4.5 to 13 times compared to a general RISC microprocessor.展开更多
The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. R...The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.展开更多
UV wavelength auto-tuned tuned output system is realized by the difference method. Controlled by the microprocessor, output wavelength auto- tracking is achieved.Besides, equipment self-checking auto-positioning and t...UV wavelength auto-tuned tuned output system is realized by the difference method. Controlled by the microprocessor, output wavelength auto- tracking is achieved.Besides, equipment self-checking auto-positioning and temperature correct are realized,The wavelength tuned output efficiency in the experiment is better than 97 %.展开更多
This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filte...This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filter to remove these two normal noise signals. Signal from the MIT-BIH electrocardiogram database was used to test the performance of the filter. From the test results, the performance of the digital filer is reDT good. The filter coefficient is an integer number, therefore, the filtering algorithm can be successfully implemented on the microprocessor.展开更多
Microprocessors such as those found in PCs and smartphones are complex in their design and nature.In recent years,an increasing number of security vulnerabilities have been found within these microprocessors that can ...Microprocessors such as those found in PCs and smartphones are complex in their design and nature.In recent years,an increasing number of security vulnerabilities have been found within these microprocessors that can leak sensitive user data and information.This report will investigate microarchitecture vulnerabilities focusing on the Spectre and Meltdown exploits and will look at what they do,how they do it and,the real-world impact these vulnerabilities can cause.Additionally,there will be an introduction to the basic concepts of how several PC components operate to support this.展开更多
The paper introduces a temperature control systembased on AT89C51 single-chip-microprocessor, and discussesthe principle , hardware structure, and software design of thissystem in detail.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61405096 and 61504058)the Introduction of Talent Research and Research Fund of Nanjing University of Posts and Telecommunications,China(Grant No.NY214158)+1 种基金the Open Fund of Laboratory of Solid State Microstructures,Nanjing University,China(Grant No.M28035)the Open Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(Grant No.SKLST201404)
文摘An ultra-broadband polarization splitter based on graphene layer-filled dual-core photonic crystal fiber （GDC-PCF） that can work in a wavelength range from 1120 nm to 1730 nm is proposed in this paper. Through optimizing fiber configuration, the polarization splitter has an extinction ratio of-56.3 dB at 1.55 μm with a fiber length of 4.8 mm. Compared with the photonic crystal fiber reported splitters, to our knowledge, the GDC-PCF splitter with the extinction ratio below-20 dB has a super wide bandwidth of 610 nm. Due to the excellent splitting characteristics, the GDC-PCF will be used in coherent optical communication systems in a wavelength range from infrared to mid-infraed.
基金supported by the National Key Research and Development Program of China “National Quality Infrastructure” (Grant No. 2021YFF0600902)。
文摘The research of high-performance polarization controllers is of great significance for expanding the application field of polarization optics. Here, a polarization switch is demonstrated by using a dual-core photonic crystal fiber(DCPCF)with four symmetrical air holes, placed above and below each core, filled with magnetic fluid(MF). The switch, which utilizes a magnetic field to change the coupling length ratio of the x and y polarization modes, enables dynamic tuning of the polarization state and extinction ratio. Numerical results show that when the working length is 36.638 mm, the magneto–optical polarization switch can operate in four communication bands, i.e., 1509 nm to 1520 nm, 1544 nm to1556 nm, 1578 nm to 1591 nm, and 1611 nm to 1624 nm. Moreover, the extinction ratio(ER) is greater than 20 d B in the fiber length range of 38.5 mm to 38.7 mm, indicating that the device has a good fault tolerance for the interception of the fiber length.
基金Project supported by the National Key Basic Research Special Foundation of China (Grant No. 2010CB327605)the National High-Technology Research and Development Program of China (Grant No. 2009AA01Z220)+2 种基金the Key Grant of the Chinese Ministry of Education (Grant No. 109015)the Discipline Co-construction Project of Beijing Municipal Commission of Education (Grant No. YB20081001301)the Open Fund of Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), Ministry of Education,and the Specialized Research Fund for the Doctoral Program of Beijing University of Posts and Telecommunications (Grant No. CX201023)
文摘This paper theoretically investigates the dependence of leaky mode coupling between inner core fundamental mode and outer core defect mode on phase and loss matching in pure silica dual-core photonic crystal fibres with the multi-pole method. The complete mode coupling can take place when both the phase and loss matching conditions are satisfied at the avoided anti-crossing wavelength. It shows the influences of cladding structure parameters including the diameters of cladding air holes d1, diameters of outer core holes d2 and hole to hole pitch A on the characteristics of leaky modes coupling. The coupled-mode theory is used to analyse the mode transition characteristics and the complete coupling can be clearly indicated by comparing the real and imaginary parts of propagation constant of the leaky modes.
文摘With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottlenecks in performance enhancement,such as drain-induced barrier lowering,reduced mobility caused by interface scattering,and limited current on/off ratios.
基金Supported by Research Project of Henan Science and Technology Foundation(0124110209,0211061900).
文摘A new kind of simple and flexible CO2 welding system was developed to carry out waveform control. The system consisted of IGBT inverter, PWM circuit and microprocessor unit （ MPU） , in which the output current of constant current （CC） power supply could be changed according to transient physical state, and the variable down slope rate control could be used to ensure a stable welding process. The welding experiment results proved the effectiveness of this control approach.
文摘Virtual memory management is always a very essential issue of the modern microprocessor design. A memory management unit (MMU) is designed to implement a virtual machine for user programs, and provides a management mechanism between the operating system and user programs. This paper analyzes the tradeoffs considered in the MMU design of Unity 11 CPU of Peking University, and introduces in detail the solution of pure hardware table walking with two level page table organization. The implementation takes care of required operations and high performances needed by modern operating systems and low costs needed by embedded systems. This solution has been silicon proven, and successfully porting the Linux 2.4.17 kernel, the XWindow system, GNOME and most application software onto the Unity platform.
文摘The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.
文摘This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed from SPWM-GTR inverter.The whole system is combined by twosubsystems,both of them are 8031 single chip microprocessors.The communication between themis coordinated by the full duplex serial port within the chip and ask-and-answer communicationmanner.The error-corrected means adopted has improved the operation reliability of the system.A series of experimental results on a 3 kW induction motor are given at the end of this paper.
文摘In this paper the authors present an analysis and the implementation of microprocessor-baseddigital phase-locked loop speed control system for an induction motor which is actuated by aSPWM-GTR inverter.The system is controlled by a 16-bit single chip microprocessor.A new type of frequency and phase detector is presented in detail,An adaptive method isadopted in speed controller.A three mode control scheme is used.These techniques are very use-ful to the improvement of the dynamic behavior of digital AC motor drive system.Experimental results show that the system is of good stability,high precision and good dynam-ic performance.
基金The High Technology Research and Development Program of China (No.2006AA01Z226)the Natural Science Foundation of Hubei (No.2007ABD002)the Ministry of Education-INTEL Information Technology Foundation (No.MOE-INTEL-08-05)
文摘We propose a novel scheme, called on-line cache resizing （OCR）, to dynamically resize the cache and meet the size requirement of each application. At each periodic interval, the scheme gathers the cache hit-miss statistics at runtime using an extra tag array. These executing statistics serve as inputs to an analytical model of cache energy. The scheme uses energy as a primary metric to dynamically increase/decrease the number of active cache ways for the next interval. The scheme minimizes the active cache size to save energy with minimal performance loss. The simulation with SPEC 2000 benchmarks shows that OCR results in an average of 38.4% energy saving compared with fixed-size caches, with only 2.0% performance loss.
文摘In the era of Internet of Things, the battery life of edge devices must be extended for sensing connection to the Internet. We aim to reduce the power consumption of the microprocessor embedded in such devices by using a novel dynamically reconfigurable accelerator. Conventional microprocessors consume a large amount of power for memory access, in registers, and for the control of the processor itself rather than computation;this decreases the energy efficiency. Dynamically reconfigurable accelerators reduce such redundant power by computing in parallel on reconfigurable switches and processing element arrays (often consisting of an arithmetic logic unit (ALU) and registers). We propose a novel dynamically reconfigurable accelerator “DYNaSTA” composed of a dynamically reconfigurable data path and static ALU arrays. The static ALU arrays process instructions in parallel without registers and improve energy efficiency. The dynamically reconfigurable data path includes registers and many switches dynamically reconfigured to resolve operand dependencies between instructions mapped on the static ALU array, and forwards appropriate operands to the static ALU array. Therefore, the DYNaSTA accelerator has more flexibility while improving the energy efficiency compared with the conventional dynamically reconfigurable accelerators. We simulated the power consumption of the proposed DYNaSTA accelerator and measured the fabricated chip. As a result, the power consumption was reduced by 69% to 86%, and the energy efficiency improved 4.5 to 13 times compared to a general RISC microprocessor.
文摘The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.
文摘UV wavelength auto-tuned tuned output system is realized by the difference method. Controlled by the microprocessor, output wavelength auto- tracking is achieved.Besides, equipment self-checking auto-positioning and temperature correct are realized,The wavelength tuned output efficiency in the experiment is better than 97 %.
文摘This paper proposes a different method to eliminate base wander and power line interference in electrocardiogram, which introduces the integer coefficient filter theory and gives the detail for designing digital filter to remove these two normal noise signals. Signal from the MIT-BIH electrocardiogram database was used to test the performance of the filter. From the test results, the performance of the digital filer is reDT good. The filter coefficient is an integer number, therefore, the filtering algorithm can be successfully implemented on the microprocessor.
文摘Microprocessors such as those found in PCs and smartphones are complex in their design and nature.In recent years,an increasing number of security vulnerabilities have been found within these microprocessors that can leak sensitive user data and information.This report will investigate microarchitecture vulnerabilities focusing on the Spectre and Meltdown exploits and will look at what they do,how they do it and,the real-world impact these vulnerabilities can cause.Additionally,there will be an introduction to the basic concepts of how several PC components operate to support this.
文摘The paper introduces a temperature control systembased on AT89C51 single-chip-microprocessor, and discussesthe principle , hardware structure, and software design of thissystem in detail.
