For the convenience of people with disability and for normal people, a demand for intelligent interfaces is ever increasing and therefore related studies are actively being conducted. Recently a study is being conduct...For the convenience of people with disability and for normal people, a demand for intelligent interfaces is ever increasing and therefore related studies are actively being conducted. Recently a study is being conducted to develop an interface through face expression, movement of the body and eye movements, and further more active attempts to use electrical signals(brainwave, electrocardiogram, electromyogram) measured from the human body is also actively being progressed. In addition, the development and the usage of mobile devices and smart devices are promoting these research activities even more. The brainwave is measured by electrical activities between nerve cells in the cerebral cortex using scalp electrodes. The brainwave is mainly used for diagnosis and treatment of diseases such as epilepsy, encephalitis, brain tumors and brain damage. As a result, the brainwave measurement methods and analytical methods were developed. Interface using the brainwave will not go through language or body behavior which is the result of the information processed by the brain but will pass directly to the system providing a brain-computer interface (BCI). This is possible because a variety of the brainwave appears depending on the human’s physical and mental state. Using the brainwave with the intelligent brain-computer interface or combining it with mobile devices and smart devices, regardless of space constraints, the brainwave measurement should be possible.[4,7] In this study, in order to measure the brainwave without spatial constraint, 16 channel compact brainwave measurements system using a high-speed wireless communications were designed. It was designed with a 16 channel to classify the various brainwave patterns that appear and for estimating the location of the nerve cells that triggered the brainwave. And in order to transmit the brainwave data within the channel without loss, a high-speed wireless communication must be possible that can enable a high-speed wireless transmission more sufficient than the Bluetooth, therefore, 802.11 compliant Wi-Fi communication methods were used to transfer the data to the PC. In addition, by using an analog front-end IC having a single-chip configuration with real-time digital filters, the miniaturization of the system was implemented and in order to verify the system Eye-blocking was used to observe the changes in the EEG signal.展开更多
This paper presents a serial synchronous scanning mode in fiat panel display (FPD) by adding a latch buffer between the serializer and the driving buffer. Comparing with conventional techniques, the proposed structu...This paper presents a serial synchronous scanning mode in fiat panel display (FPD) by adding a latch buffer between the serializer and the driving buffer. Comparing with conventional techniques, the proposed structure can efficiently reduce the brightness loss and improve the transmission performance. Theoretical analysis and experimental results show that the ratio between the lightest weight display time and the relative transmission time is a tradeoff between brightness loss and transmission efficiency.展开更多
The multi-tone interference suppression in HF serial data transmission systemsis analyzed.Analytic expression for the tap weights and minimum mean square errors of theadaptive equalizer in HF serial systems are obtain...The multi-tone interference suppression in HF serial data transmission systemsis analyzed.Analytic expression for the tap weights and minimum mean square errors of theadaptive equalizer in HF serial systems are obtained.The rate of convergence of equalizer indicatethat the equalizer in HF serial system can not only track the rapid variation of HF channel butalso suppress the multi-tone interferences perfectly.展开更多
When the operation speed of the high-speed train increases and the weight of the carbody becomes lighter,not only does the sensitivity of the wheel/rail contact get higher,but also the vibration frequency range of the...When the operation speed of the high-speed train increases and the weight of the carbody becomes lighter,not only does the sensitivity of the wheel/rail contact get higher,but also the vibration frequency range of the vehicle system gets enlarged and more frequencies are transmitted from the wheelset to the carbody.It is important to investigate the vibration characteristics and the dynamic frequency transmission from the wheel/rail interface to the carbody of the high-speed electric multi-uint(EMU).An elastic highspeed vehicle dynamics model is established in which the carbody,bogieframes,and wheelsets are all dealt with as flexible body.A rigid high-speed vehicle dynamics model is set up to compare with the simulation results of the elastic model.In the rigid vehicle model,the carbody,bogieframes and wheelsets are treated as rigid component while the suspension and structure parameters are the same as used in the elastic model.The dynamic characteristic of the elastic high speed vehicle is investigated in time and frequency domains and the di ff erence of the acceleration,frequency distribution and transmission of the two types of models are presented.The results show that the spectrum power density of the vehicle decreases from the wheelset to the carbody and the acceleration transmission ratio is approximately from 1%to 10%for each suspension system.The frequency of the wheelset rotation is evident in the vibration of the flexible model and is transmitted from the wheelset to the bogieframe and to thecarbody.The results of the flexible model are more reasonable than that of the rigid model.A field test data of the high speed train are presented to verify the simulation results.It shows that the simulation results are coincident with the field test data.展开更多
This paper presents an analysis method, based on MacCormack's technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calcul...This paper presents an analysis method, based on MacCormack's technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements. The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process. Therefore, it is very convenient to program this method. It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks. The proposed method is second-order-accurate. Numerical experiment is presented to demonstrate its accuracy and efficiency.展开更多
When an electromagnetic signal transmits through a coaxial cable, it propagates at speed determined by the dielectrics of insulator between the cooper core wire and the metallic shield. However, we demonstrate here th...When an electromagnetic signal transmits through a coaxial cable, it propagates at speed determined by the dielectrics of insulator between the cooper core wire and the metallic shield. However, we demonstrate here that, once the shielding layer of the coaxial cable is cut into two parts leaving a small gap, while the copper core wire is still perfectly connected, a remarkable transmission delay immediately appears in the system. We have revealed by both computational simulation and experiments that, when the gap spacing between two parts of the shielding layer is small, this delay is mostly determined by the overall geometrical parameters of the conductive boundary which connects two parts of the cut shielding layer. A reduced analytic formula for the transmission delay related with geometrical parameters, which is based on an inductive model of the transmission system, matches well with the fitted formula of the simulated delay. This above structure is analog to the situation that an interconnect is between two inter-modules in a circuit. The results suggest that for high speed circuits and systems, parasitic inductance should be taken into full consideration, and compact conductive packaging is favorable for reducing transmission delay of inter-modules, therefore enhancing the performance of the system.展开更多
在广播电视行业,4K、8K超高清技术的快速发展,对于信号传输产生了更高的要求,需要更高的带宽和更低的延迟。在这种情况下,传统的串行数字接口(Serial Digital Interface,SDI)技术已经不能满足,需要向网际互连协议(Internet Protocol,IP...在广播电视行业,4K、8K超高清技术的快速发展,对于信号传输产生了更高的要求,需要更高的带宽和更低的延迟。在这种情况下,传统的串行数字接口(Serial Digital Interface,SDI)技术已经不能满足,需要向网际互连协议(Internet Protocol,IP)化转化。针对SDI技术的局限性以及IP技术的优势进行阐述,发现IP化不仅可以提升传输效率、降低传输成本,还可以促进广播电视行业的创新和发展。展开更多
Aero-optical effects for starlight transmission in the high-speed flow field will reduce the accuracy of the star sensor on an aircraft.Numerical simulations for aero-optical effects usually require plenty of calculat...Aero-optical effects for starlight transmission in the high-speed flow field will reduce the accuracy of the star sensor on an aircraft.Numerical simulations for aero-optical effects usually require plenty of calculations,which cause difficulties when designing a celestial navigation system for a high-speed aircraft.In this study,an Aero-Optical Simulator For Starlight Transmission(AOSST)in the boundary layer is developed.It effectively reduces the computational burden compared to that of the widely used CFD simulation,and it achieves satisfactory accuracy.In this simulator,gas ellipsoids satisfying certain design rules are used to simulate coherent density structures in boundary layers.Design rules for the gas ellipsoids are found from published experimental and high-fidelity CFD simulation results.The generated wavefront distortion by AOSST is anchored with the scale law for aero-optical distortion in the boundary layer by determining some control parameters,which enables the simulator to output reliable results over a wide range of flight states.Four numerical examples are provided to verify the performance of AOSST.The results demonstrate that AOSST is able to simulate the directional dependence of aero-optical distortions in boundary layers,the variation trend of distorted wavefront shapes with Reynolds number,and the grayscale distribution on the disturbed star map.展开更多
In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analy...In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.展开更多
We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/...We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/s experiment.展开更多
The presentation will give an overview over different classes of signal impairments in ultra-long-haul and high-speed optical WDM transmission systems and adequate approaches for suppression, mitigation or compensatio...The presentation will give an overview over different classes of signal impairments in ultra-long-haul and high-speed optical WDM transmission systems and adequate approaches for suppression, mitigation or compensation are discussed.展开更多
在不含磁芯的无线电能传输WPT(wireless power transmission)系统中,由磁耦合系统引起的损耗是系统损耗的主要组成部分之一,而磁耦合系统的损耗由接收线圈、发射线圈的电阻以及流经收发线圈的电流所决定。结合串/串S/S(series/series)...在不含磁芯的无线电能传输WPT(wireless power transmission)系统中,由磁耦合系统引起的损耗是系统损耗的主要组成部分之一,而磁耦合系统的损耗由接收线圈、发射线圈的电阻以及流经收发线圈的电流所决定。结合串/串S/S(series/series)补偿拓扑无线电能传输的电路响应特性,分析磁耦合系统的线圈感量、线圈电阻与线圈匝数的关系,提出了根据发射、接收线圈电流工况调整收发线圈匝数的磁耦合系统线圈匝数组合优化设计方案。绕制3组不同匝数组合的收发线圈(含优化匝数组合及两组对照匝数组合线圈)用以验证优化方案的可行性。仿真及实验结果均表明:在相同工况下,优化组合方案的线圈总损耗均低于对照组,且整体样机的效率均高于对照组。展开更多
文摘For the convenience of people with disability and for normal people, a demand for intelligent interfaces is ever increasing and therefore related studies are actively being conducted. Recently a study is being conducted to develop an interface through face expression, movement of the body and eye movements, and further more active attempts to use electrical signals(brainwave, electrocardiogram, electromyogram) measured from the human body is also actively being progressed. In addition, the development and the usage of mobile devices and smart devices are promoting these research activities even more. The brainwave is measured by electrical activities between nerve cells in the cerebral cortex using scalp electrodes. The brainwave is mainly used for diagnosis and treatment of diseases such as epilepsy, encephalitis, brain tumors and brain damage. As a result, the brainwave measurement methods and analytical methods were developed. Interface using the brainwave will not go through language or body behavior which is the result of the information processed by the brain but will pass directly to the system providing a brain-computer interface (BCI). This is possible because a variety of the brainwave appears depending on the human’s physical and mental state. Using the brainwave with the intelligent brain-computer interface or combining it with mobile devices and smart devices, regardless of space constraints, the brainwave measurement should be possible.[4,7] In this study, in order to measure the brainwave without spatial constraint, 16 channel compact brainwave measurements system using a high-speed wireless communications were designed. It was designed with a 16 channel to classify the various brainwave patterns that appear and for estimating the location of the nerve cells that triggered the brainwave. And in order to transmit the brainwave data within the channel without loss, a high-speed wireless communication must be possible that can enable a high-speed wireless transmission more sufficient than the Bluetooth, therefore, 802.11 compliant Wi-Fi communication methods were used to transfer the data to the PC. In addition, by using an analog front-end IC having a single-chip configuration with real-time digital filters, the miniaturization of the system was implemented and in order to verify the system Eye-blocking was used to observe the changes in the EEG signal.
基金Project supported by the Science Foundation of Shanghai Municipal Commission of Science and Technology (Grant Nos.055207041, 047062012)
文摘This paper presents a serial synchronous scanning mode in fiat panel display (FPD) by adding a latch buffer between the serializer and the driving buffer. Comparing with conventional techniques, the proposed structure can efficiently reduce the brightness loss and improve the transmission performance. Theoretical analysis and experimental results show that the ratio between the lightest weight display time and the relative transmission time is a tradeoff between brightness loss and transmission efficiency.
文摘The multi-tone interference suppression in HF serial data transmission systemsis analyzed.Analytic expression for the tap weights and minimum mean square errors of theadaptive equalizer in HF serial systems are obtained.The rate of convergence of equalizer indicatethat the equalizer in HF serial system can not only track the rapid variation of HF channel butalso suppress the multi-tone interferences perfectly.
基金supported by the National Natural Science Foundation of China(U1134201 and 51175032)the National Hitech Research and Development Program of China(973 Program)(211CD71104)
文摘When the operation speed of the high-speed train increases and the weight of the carbody becomes lighter,not only does the sensitivity of the wheel/rail contact get higher,but also the vibration frequency range of the vehicle system gets enlarged and more frequencies are transmitted from the wheelset to the carbody.It is important to investigate the vibration characteristics and the dynamic frequency transmission from the wheel/rail interface to the carbody of the high-speed electric multi-uint(EMU).An elastic highspeed vehicle dynamics model is established in which the carbody,bogieframes,and wheelsets are all dealt with as flexible body.A rigid high-speed vehicle dynamics model is set up to compare with the simulation results of the elastic model.In the rigid vehicle model,the carbody,bogieframes and wheelsets are treated as rigid component while the suspension and structure parameters are the same as used in the elastic model.The dynamic characteristic of the elastic high speed vehicle is investigated in time and frequency domains and the di ff erence of the acceleration,frequency distribution and transmission of the two types of models are presented.The results show that the spectrum power density of the vehicle decreases from the wheelset to the carbody and the acceleration transmission ratio is approximately from 1%to 10%for each suspension system.The frequency of the wheelset rotation is evident in the vibration of the flexible model and is transmitted from the wheelset to the bogieframe and to thecarbody.The results of the flexible model are more reasonable than that of the rigid model.A field test data of the high speed train are presented to verify the simulation results.It shows that the simulation results are coincident with the field test data.
文摘This paper presents an analysis method, based on MacCormack's technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements. The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process. Therefore, it is very convenient to program this method. It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks. The proposed method is second-order-accurate. Numerical experiment is presented to demonstrate its accuracy and efficiency.
文摘When an electromagnetic signal transmits through a coaxial cable, it propagates at speed determined by the dielectrics of insulator between the cooper core wire and the metallic shield. However, we demonstrate here that, once the shielding layer of the coaxial cable is cut into two parts leaving a small gap, while the copper core wire is still perfectly connected, a remarkable transmission delay immediately appears in the system. We have revealed by both computational simulation and experiments that, when the gap spacing between two parts of the shielding layer is small, this delay is mostly determined by the overall geometrical parameters of the conductive boundary which connects two parts of the cut shielding layer. A reduced analytic formula for the transmission delay related with geometrical parameters, which is based on an inductive model of the transmission system, matches well with the fitted formula of the simulated delay. This above structure is analog to the situation that an interconnect is between two inter-modules in a circuit. The results suggest that for high speed circuits and systems, parasitic inductance should be taken into full consideration, and compact conductive packaging is favorable for reducing transmission delay of inter-modules, therefore enhancing the performance of the system.
文摘在广播电视行业,4K、8K超高清技术的快速发展,对于信号传输产生了更高的要求,需要更高的带宽和更低的延迟。在这种情况下,传统的串行数字接口(Serial Digital Interface,SDI)技术已经不能满足,需要向网际互连协议(Internet Protocol,IP)化转化。针对SDI技术的局限性以及IP技术的优势进行阐述,发现IP化不仅可以提升传输效率、降低传输成本,还可以促进广播电视行业的创新和发展。
基金supported by the National Defense PreResearch Foundation of China(No.JCKY2016601C005)the Science and Technology on Space Intelligent Control Laboratory of China(No.ZDSYS-2018-03)。
文摘Aero-optical effects for starlight transmission in the high-speed flow field will reduce the accuracy of the star sensor on an aircraft.Numerical simulations for aero-optical effects usually require plenty of calculations,which cause difficulties when designing a celestial navigation system for a high-speed aircraft.In this study,an Aero-Optical Simulator For Starlight Transmission(AOSST)in the boundary layer is developed.It effectively reduces the computational burden compared to that of the widely used CFD simulation,and it achieves satisfactory accuracy.In this simulator,gas ellipsoids satisfying certain design rules are used to simulate coherent density structures in boundary layers.Design rules for the gas ellipsoids are found from published experimental and high-fidelity CFD simulation results.The generated wavefront distortion by AOSST is anchored with the scale law for aero-optical distortion in the boundary layer by determining some control parameters,which enables the simulator to output reliable results over a wide range of flight states.Four numerical examples are provided to verify the performance of AOSST.The results demonstrate that AOSST is able to simulate the directional dependence of aero-optical distortions in boundary layers,the variation trend of distorted wavefront shapes with Reynolds number,and the grayscale distribution on the disturbed star map.
基金supported by Science Foundation for Youthful Teachers of Anhui University (Grant No.2007jql104)
文摘In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.
文摘We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/s experiment.
文摘The presentation will give an overview over different classes of signal impairments in ultra-long-haul and high-speed optical WDM transmission systems and adequate approaches for suppression, mitigation or compensation are discussed.
文摘在不含磁芯的无线电能传输WPT(wireless power transmission)系统中,由磁耦合系统引起的损耗是系统损耗的主要组成部分之一,而磁耦合系统的损耗由接收线圈、发射线圈的电阻以及流经收发线圈的电流所决定。结合串/串S/S(series/series)补偿拓扑无线电能传输的电路响应特性,分析磁耦合系统的线圈感量、线圈电阻与线圈匝数的关系,提出了根据发射、接收线圈电流工况调整收发线圈匝数的磁耦合系统线圈匝数组合优化设计方案。绕制3组不同匝数组合的收发线圈(含优化匝数组合及两组对照匝数组合线圈)用以验证优化方案的可行性。仿真及实验结果均表明:在相同工况下,优化组合方案的线圈总损耗均低于对照组,且整体样机的效率均高于对照组。