The wireless capsule endoscope,as a small electronic device,has conquered some limitations of traditional wired diagnosing tools,such as the uncomfortableness of the cables for the patient and the inability to examine...The wireless capsule endoscope,as a small electronic device,has conquered some limitations of traditional wired diagnosing tools,such as the uncomfortableness of the cables for the patient and the inability to examine the very convoluted small intestine section.However,this technique is still encountering a lot of practical challenges and is looking for feasible improvements.This work investigates the RF performance of the wireless capsule endoscope system by studying the electromagnetic(EM) wave propagation within the human body.A wireless capsule endoscopy transmission channel model is constructed to serve the purpose of investigating signal attenuations according to the relative position between the transmitter and the receiver.Within 300-500 MHz,the S_(21) results are regular and do not display any sudden changes,which allows a suitable expression to be derived for S_(21) in terms of frequency and offset.The results provide useful information for capsule localization.展开更多
This contribution describes the use of chromatic techniques for quantifying signatures of partial discharges(PD).A brief description of the basis of chromatic monitoring is given along with explanations of how the app...This contribution describes the use of chromatic techniques for quantifying signatures of partial discharges(PD).A brief description of the basis of chromatic monitoring is given along with explanations of how the approach may be applied for addressing signals produced by PDs.Laboratory test data from several sources for different types of PDs,operating conditions and geometries have been subjected to the chromatic procedures.These include a point-plane gap,a sphere in a liquid and treeing in a cable.Chromatic changes in PD signals have been investigated as a function of the amplitude of the alternating voltage producing the PD,the time duration before full electrical breakdown and for different forms of PDs.Results of the chromatic processing of these data are presented in the form of a number of chromatic maps relating to different quarter cycles of the alternating voltage producing the PDs.The results show the potential of the chromatic techniques for indicating the likelihood of full electrical breakdown and for distinguishing between certain forms of PDs.A summary of the chromatic processing procedures is presented for producing chromatic maps and for adaptation in further exploring PD signal features.展开更多
This work is devoted to the experimental investigation of an AC argon gliding arc discharge at atmospheric pressure.The dynamic behaviour of the argon gliding arc plasma is investigated by the oscillations of the elec...This work is devoted to the experimental investigation of an AC argon gliding arc discharge at atmospheric pressure.The dynamic behaviour of the argon gliding arc plasma is investigated by the oscillations of the electrical signals,while the time-resolved arc root motion behaviour on the electrode wall is analyzed by high-speed photography.It is found that the anode and cathode arc roots exhibit different motion behaviour on the electrode surface.In addition,emission spectroscopic technique has been employed to determine the axial distribution of the gas temperature and electron density in the argon gliding arc plasma.展开更多
A new approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems was proposed.This approach is based on assigning powers to the different subcarriers of OFDM...A new approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems was proposed.This approach is based on assigning powers to the different subcarriers of OFDM using an unequal power distribution strategy.In addition,a reduced complexity selective mapping (RC-SLM) scheme was proposed.The proposed scheme is based on partitioning the frequency domain symbol sequence into several sub-blocks,and then each sub-block is multiplied by different phase sequences whose length is shorter than that used in the conventional SLM scheme.Then,a kind of low complexity conversions is used to replace the IFFT blocks.The performance of the proposed RC-SLM scheme along with the new approach was studied with computer simulation.The obtained results show that the proposed RC-SLM scheme is able to achieve the lowest computational complexity when compared with other low complexity schemes proposed in the literature while at the same time improves the PAPR reduction performance by about 0.3 dB.展开更多
基金Project (BK20131183) supported by the Natural Science Foundation of Jiangsu Province,ChinaProjects (RDF-14-03-24,RDF-14-02-48) supported by Research Development Fund of Xi’an Jiaotong-Liverpool University,China
文摘The wireless capsule endoscope,as a small electronic device,has conquered some limitations of traditional wired diagnosing tools,such as the uncomfortableness of the cables for the patient and the inability to examine the very convoluted small intestine section.However,this technique is still encountering a lot of practical challenges and is looking for feasible improvements.This work investigates the RF performance of the wireless capsule endoscope system by studying the electromagnetic(EM) wave propagation within the human body.A wireless capsule endoscopy transmission channel model is constructed to serve the purpose of investigating signal attenuations according to the relative position between the transmitter and the receiver.Within 300-500 MHz,the S_(21) results are regular and do not display any sudden changes,which allows a suitable expression to be derived for S_(21) in terms of frequency and offset.The results provide useful information for capsule localization.
文摘This contribution describes the use of chromatic techniques for quantifying signatures of partial discharges(PD).A brief description of the basis of chromatic monitoring is given along with explanations of how the approach may be applied for addressing signals produced by PDs.Laboratory test data from several sources for different types of PDs,operating conditions and geometries have been subjected to the chromatic procedures.These include a point-plane gap,a sphere in a liquid and treeing in a cable.Chromatic changes in PD signals have been investigated as a function of the amplitude of the alternating voltage producing the PD,the time duration before full electrical breakdown and for different forms of PDs.Results of the chromatic processing of these data are presented in the form of a number of chromatic maps relating to different quarter cycles of the alternating voltage producing the PDs.The results show the potential of the chromatic techniques for indicating the likelihood of full electrical breakdown and for distinguishing between certain forms of PDs.A summary of the chromatic processing procedures is presented for producing chromatic maps and for adaptation in further exploring PD signal features.
基金Project supported by the Royal Society and the Royal Academy of Engineering
文摘This work is devoted to the experimental investigation of an AC argon gliding arc discharge at atmospheric pressure.The dynamic behaviour of the argon gliding arc plasma is investigated by the oscillations of the electrical signals,while the time-resolved arc root motion behaviour on the electrode wall is analyzed by high-speed photography.It is found that the anode and cathode arc roots exhibit different motion behaviour on the electrode surface.In addition,emission spectroscopic technique has been employed to determine the axial distribution of the gas temperature and electron density in the argon gliding arc plasma.
文摘A new approach for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems was proposed.This approach is based on assigning powers to the different subcarriers of OFDM using an unequal power distribution strategy.In addition,a reduced complexity selective mapping (RC-SLM) scheme was proposed.The proposed scheme is based on partitioning the frequency domain symbol sequence into several sub-blocks,and then each sub-block is multiplied by different phase sequences whose length is shorter than that used in the conventional SLM scheme.Then,a kind of low complexity conversions is used to replace the IFFT blocks.The performance of the proposed RC-SLM scheme along with the new approach was studied with computer simulation.The obtained results show that the proposed RC-SLM scheme is able to achieve the lowest computational complexity when compared with other low complexity schemes proposed in the literature while at the same time improves the PAPR reduction performance by about 0.3 dB.
