In this paper the crosstalk between nonuniform transmission lines is examined. Firstly, methods for prediction of crosstalk between microstrip transmission lines are reviewed. Classical coupled transmission line theor...In this paper the crosstalk between nonuniform transmission lines is examined. Firstly, methods for prediction of crosstalk between microstrip transmission lines are reviewed. Classical coupled transmission line theory is used for uniform lines and cannot be used for nonuniform transmission lines. Secondly, equations are derived which can be solved to obtain formulas for the near-end and far-end crosstalk for nonuniform transmission lines. Finally, an example is worked which illustrates the crosstalk between three conductor nonuniform transmission lines. Obtained theoretical results were compared with simulations data. Comparison results shown that theoretical and simulation results are approximately the same.展开更多
Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of t...Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of the line topology switched Ethernet as a data acquisition network.Network calculus theory,which has been successfully applied to assess the real-time performance of packet-switched networks,is used to analyze the networks.To properly describe the activity of switches,a novel approach of modeling data flows into or out of switches is addressed.Based on our model,a concisely analytical expression of the maximal end-to-end delay in line topology switched Ethernet is derived.Finally,the relative simulation results are demonstrated.These results agree well with the analytical results,and thus they validate the data flow modeling techniques.展开更多
Anewfault location algorithmfor double-circuit transmissionlines is described inthis paper.Theproposed method uses data extractedfromtwo ends of the transmissionlines andthus eliminates the effects ofthe source impeda...Anewfault location algorithmfor double-circuit transmissionlines is described inthis paper.Theproposed method uses data extractedfromtwo ends of the transmissionlines andthus eliminates the effects ofthe source impedance andthe fault resistance.The distributed parameter model and the modal transformationare also employed.Depending on modal transformation,the coupled equations of the lines are converted intodecoupled ones.Inthis way,the mutual coupling effects between adjacent circuits of the lines are eliminatedandtherefore an accurate fault location can be achieved.The proposed methodis tested via digital simulationusing EMTP in conjunction with MATLAB.The test results corroborate the high accuracy of the proposedmethod.展开更多
Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits o...Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.展开更多
An open-ended coaxial line reflection method especially suitable for meas-uring the dielectric properties of biological tissue in vivo is described.This method offersthe advantage of not requiring any special preparat...An open-ended coaxial line reflection method especially suitable for meas-uring the dielectric properties of biological tissue in vivo is described.This method offersthe advantage of not requiring any special preparation of the samples to be measured but aclose contact with the open end of a coaxial line.It is,therefore,very convenient to acquirea large number of measurement data in broad band rapidly.The method may also be usedto measure the properties of other substances.The measuring system consists of a networkanalyzer controlled by a microcomputer and calibrated by using ANA procedure to elimi-hate the influnce of error network introduced by the adapter,some connectors,etc.In or-der to reach higher accuracy,the iterative method is used to determine the parameters ofthe equivalent circuit.Measurements of permeativities of some living tissues have been per-formed in the frequency band of 0.5-2GHz.Compared with the results known in somepapers,the validity of this method has been confirmed.The difference in dielectric proper-ties between living and dead tissues,and the tissue permeativites(ε)versus frequency andduration of measurement after death have also been measured.展开更多
目的探讨高效on-line血液透析滤过（hemodiafiltration,HDF）联合血液透析（hemodialysis,HD）对维持性透析（maintenance hemodialysis,MHD）患者生存质量和长期生存率的影响。方法80例MHD患者分为高效on-line血液透析滤过联合血液透...目的探讨高效on-line血液透析滤过（hemodiafiltration,HDF）联合血液透析（hemodialysis,HD）对维持性透析（maintenance hemodialysis,MHD）患者生存质量和长期生存率的影响。方法80例MHD患者分为高效on-line血液透析滤过联合血液透析组（HDF＋HD组,50例）和常规血液透析组（HD组,30例）,观察比较两组入组时及治疗第3、6、12、36、60月患者的透析充分性、营养状态、生存质量和5年生存率。结果 HDF＋HD组尿素清除指数（urea clearance index,Kt/V）、血磷（phosphorus,Pi）、HCO_3-、β_2微球蛋白（β_2-microglobulin,β_2-MG）、C反应蛋白（c-reactive protein,CRP）、血清白蛋白（albumin,ALB）、主观综合营养评估（subjective global nutritional assessment,SGA）及SF-36健康调查简表（the MOS item short from health survey SF-36,SF-36）在治疗第12、36、60月时均较同期单纯HD组明显改善（Kt/V：t=2.604,P=0.011;t=2.600,P=0.011;t=2.598,P=0.011。Pi：t=-3.080,P=0.003;t=-3.172,P=0.002;t=-4.733,P〈0.001。HCO_3-：t=7.693,P〈0.001;t=12.917,P〈0.001;t=8.145,P〈0.001。β_2-MG：t=-20.369,P〈0.001;t=-21.205,P〈0.001;t=-23.658,P〈0.001。CRP：t=-12.983,P〈0.001;t=-19.689,P〈0.001;t=-17.395,P〈0.001。ALB：t=6.618,P〈0.001;t=7.688,P〈0.001;t=7.519,P〈0.001。SGA：t=7.104,P〈0.001;t=8.933,P〈0.001;t=6.381,P〈0.001。SF-36：t=17.366,P〈0.001;t=13.971,P〈0.001;t=11.748,P〈0.001）。Kaplan-Meier生存曲线显示,HDF＋HD组生存率较HD组高,差异有统计学意义（Log Rank检验,χ^2=3.917,P=0.048）。多因素分析结果提示SF-36与β_2-MG呈负相关（B=-0.352,P〈0.001）,与SGA呈正相关（B=0.772,P〈0.001）。结论与常规HD相比,高效on-line血液透析滤过联合血液透析能改善维持性透析患者的生存质量和长期生存率,增加中大分子毒素的清除和改善营养状态可能是改善生存质量的关键因素。展开更多
针对云端单一集中数据处理时效性低、架空线路上鸟巢检测精度不高、模型对边缘计算设备算力高消耗以及目标定位不准确的问题,提出了一种基于云边端协作的架空线路鸟巢检测与定位算法。该算法通过云、终、边缘3端的协作,解决了云端集中...针对云端单一集中数据处理时效性低、架空线路上鸟巢检测精度不高、模型对边缘计算设备算力高消耗以及目标定位不准确的问题,提出了一种基于云边端协作的架空线路鸟巢检测与定位算法。该算法通过云、终、边缘3端的协作,解决了云端集中处理效率低的问题,并通过云边数据可视化协作解决由于角度及光线引起的图像不清晰问题。为了提高架空线路鸟巢检测的精度,该算法在YOLOv5x模型基础上进行了优化。首先,通过将主干特征提取网络中的C3模块替换为C2f模块,并在最后一层加入SE(squeeze and excitation)注意力模块,以提升模型对小目标的检测能力。其次,将激活函数替换为Mish函数,解决训练梯度饱和导致神经元停止学习的问题。为了降低模型对边缘计算设备算力的消耗,对改进后的模型进行剪枝微调以降低模型参数规模。基于此优化模型,提出了三维目标定位算法,结合GIS(geographic information system)系统对定位结果进行修正,实现了对检测目标的精准定位。实验数据显示,改进后的模型平均精度均值达到93.25%,比原YOLOv5x模型提升了3.44%,优化后的模型剪枝率达到45%。检测目标经过三维空间建模计算并通过位置修正能够定位到相应的杆塔,有效指导工作人员快速准确排除隐患。展开更多
文摘In this paper the crosstalk between nonuniform transmission lines is examined. Firstly, methods for prediction of crosstalk between microstrip transmission lines are reviewed. Classical coupled transmission line theory is used for uniform lines and cannot be used for nonuniform transmission lines. Secondly, equations are derived which can be solved to obtain formulas for the near-end and far-end crosstalk for nonuniform transmission lines. Finally, an example is worked which illustrates the crosstalk between three conductor nonuniform transmission lines. Obtained theoretical results were compared with simulations data. Comparison results shown that theoretical and simulation results are approximately the same.
文摘Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of the line topology switched Ethernet as a data acquisition network.Network calculus theory,which has been successfully applied to assess the real-time performance of packet-switched networks,is used to analyze the networks.To properly describe the activity of switches,a novel approach of modeling data flows into or out of switches is addressed.Based on our model,a concisely analytical expression of the maximal end-to-end delay in line topology switched Ethernet is derived.Finally,the relative simulation results are demonstrated.These results agree well with the analytical results,and thus they validate the data flow modeling techniques.
文摘Anewfault location algorithmfor double-circuit transmissionlines is described inthis paper.Theproposed method uses data extractedfromtwo ends of the transmissionlines andthus eliminates the effects ofthe source impedance andthe fault resistance.The distributed parameter model and the modal transformationare also employed.Depending on modal transformation,the coupled equations of the lines are converted intodecoupled ones.Inthis way,the mutual coupling effects between adjacent circuits of the lines are eliminatedandtherefore an accurate fault location can be achieved.The proposed methodis tested via digital simulationusing EMTP in conjunction with MATLAB.The test results corroborate the high accuracy of the proposedmethod.
文摘Security constrained multi area multi objective dynamic economic dispatch (SCMAMODED) with renewable energy (RE) and all the possible MTDC stability constraints is formulated for the first time. The stability merits of multi terminal DC (MTDC) tie lines as compared to the traditional HVAC forms the main objective of this paper. Probabilistic load flow (PLF) is applied to determine the system parameters while the uncertainties are modelled using Scenario Based Method (SBM). The simulation results reveal that with the use of MTDC tie lines, the frequency and voltage stability in the MAMODED with renewable energy sources (RES) are enhanced while keeping the MTDC power exchange interface nodes at secure levels.
文摘An open-ended coaxial line reflection method especially suitable for meas-uring the dielectric properties of biological tissue in vivo is described.This method offersthe advantage of not requiring any special preparation of the samples to be measured but aclose contact with the open end of a coaxial line.It is,therefore,very convenient to acquirea large number of measurement data in broad band rapidly.The method may also be usedto measure the properties of other substances.The measuring system consists of a networkanalyzer controlled by a microcomputer and calibrated by using ANA procedure to elimi-hate the influnce of error network introduced by the adapter,some connectors,etc.In or-der to reach higher accuracy,the iterative method is used to determine the parameters ofthe equivalent circuit.Measurements of permeativities of some living tissues have been per-formed in the frequency band of 0.5-2GHz.Compared with the results known in somepapers,the validity of this method has been confirmed.The difference in dielectric proper-ties between living and dead tissues,and the tissue permeativites(ε)versus frequency andduration of measurement after death have also been measured.
文摘目的探讨高效on-line血液透析滤过（hemodiafiltration,HDF）联合血液透析（hemodialysis,HD）对维持性透析（maintenance hemodialysis,MHD）患者生存质量和长期生存率的影响。方法80例MHD患者分为高效on-line血液透析滤过联合血液透析组（HDF＋HD组,50例）和常规血液透析组（HD组,30例）,观察比较两组入组时及治疗第3、6、12、36、60月患者的透析充分性、营养状态、生存质量和5年生存率。结果 HDF＋HD组尿素清除指数（urea clearance index,Kt/V）、血磷（phosphorus,Pi）、HCO_3-、β_2微球蛋白（β_2-microglobulin,β_2-MG）、C反应蛋白（c-reactive protein,CRP）、血清白蛋白（albumin,ALB）、主观综合营养评估（subjective global nutritional assessment,SGA）及SF-36健康调查简表（the MOS item short from health survey SF-36,SF-36）在治疗第12、36、60月时均较同期单纯HD组明显改善（Kt/V：t=2.604,P=0.011;t=2.600,P=0.011;t=2.598,P=0.011。Pi：t=-3.080,P=0.003;t=-3.172,P=0.002;t=-4.733,P〈0.001。HCO_3-：t=7.693,P〈0.001;t=12.917,P〈0.001;t=8.145,P〈0.001。β_2-MG：t=-20.369,P〈0.001;t=-21.205,P〈0.001;t=-23.658,P〈0.001。CRP：t=-12.983,P〈0.001;t=-19.689,P〈0.001;t=-17.395,P〈0.001。ALB：t=6.618,P〈0.001;t=7.688,P〈0.001;t=7.519,P〈0.001。SGA：t=7.104,P〈0.001;t=8.933,P〈0.001;t=6.381,P〈0.001。SF-36：t=17.366,P〈0.001;t=13.971,P〈0.001;t=11.748,P〈0.001）。Kaplan-Meier生存曲线显示,HDF＋HD组生存率较HD组高,差异有统计学意义（Log Rank检验,χ^2=3.917,P=0.048）。多因素分析结果提示SF-36与β_2-MG呈负相关（B=-0.352,P〈0.001）,与SGA呈正相关（B=0.772,P〈0.001）。结论与常规HD相比,高效on-line血液透析滤过联合血液透析能改善维持性透析患者的生存质量和长期生存率,增加中大分子毒素的清除和改善营养状态可能是改善生存质量的关键因素。
文摘针对云端单一集中数据处理时效性低、架空线路上鸟巢检测精度不高、模型对边缘计算设备算力高消耗以及目标定位不准确的问题,提出了一种基于云边端协作的架空线路鸟巢检测与定位算法。该算法通过云、终、边缘3端的协作,解决了云端集中处理效率低的问题,并通过云边数据可视化协作解决由于角度及光线引起的图像不清晰问题。为了提高架空线路鸟巢检测的精度,该算法在YOLOv5x模型基础上进行了优化。首先,通过将主干特征提取网络中的C3模块替换为C2f模块,并在最后一层加入SE(squeeze and excitation)注意力模块,以提升模型对小目标的检测能力。其次,将激活函数替换为Mish函数,解决训练梯度饱和导致神经元停止学习的问题。为了降低模型对边缘计算设备算力的消耗,对改进后的模型进行剪枝微调以降低模型参数规模。基于此优化模型,提出了三维目标定位算法,结合GIS(geographic information system)系统对定位结果进行修正,实现了对检测目标的精准定位。实验数据显示,改进后的模型平均精度均值达到93.25%,比原YOLOv5x模型提升了3.44%,优化后的模型剪枝率达到45%。检测目标经过三维空间建模计算并通过位置修正能够定位到相应的杆塔,有效指导工作人员快速准确排除隐患。
