The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the t...The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.展开更多
Objective:To observe the clinical improvement of Kāiqiàotōngluò(induce resuscitation and remove obstruction in meridians)acupuncture combined with repetitive transcranial magnetic stimulation(rTMS)in patie...Objective:To observe the clinical improvement of Kāiqiàotōngluò(induce resuscitation and remove obstruction in meridians)acupuncture combined with repetitive transcranial magnetic stimulation(rTMS)in patients with hand dysfunction after stroke,and to provide evidence for its extensive application in the future.Methods:Sixty patients with the problem of hand dysfunction were divided into the observation group and the control group randomly.The two groups of patients were treated with the basic treatment,the observation group received Kdiqiaotongluo acupuncture combined with rTMS,and the control group only received the rTMS treatment.Broetz hand function scale,hemiplegic hand function grading,and modified Barthel index were used to evaluate the hand function of the patients in two groups before and after treatment.Results:After treatment,Broetz score of the patients in observation group and control group were significantly lower than that before treatment,and Broetz score of the patients in observation group was lower than that of control group(all P<0.05);As for the hemiplegic hand function grading,24 cases in the observation group improved,the improvement rate was 80.0%,and 8 cases in the control group improved,the improvement rate was only 26.7%.The improvement rate of observation group was significantly better than that of control group(P<0.01);the Barthel index scores of the observation group and the control group were significantly improved after treatment,and the observation group was better than the control group(both P<0.05).Conclusion:The Kāiqiàotōngluòacupuncture combined with rTMS can improve the hand dysfunction of patients after stroke,and it is worthy of clinical application.展开更多
为有效实现数字射线扫描成像检测系统性能的定量分析评价,据此进行检测工艺参数的优化,对数字射线扫描成像检测系统调制传递函数(Modulation transfer function,MTF)进行了测试分析。采用刀口工具、双线型像质计、分辨率测试卡,对系统...为有效实现数字射线扫描成像检测系统性能的定量分析评价,据此进行检测工艺参数的优化,对数字射线扫描成像检测系统调制传递函数(Modulation transfer function,MTF)进行了测试分析。采用刀口工具、双线型像质计、分辨率测试卡,对系统在不同焦点大小、放大倍数、运动方向的检测情况,分别进行了MTF的测试并进行了比较。结果表明,双线型像质计与分辨率测试卡的测试结果基本一致,但双线型像质计更便于对比度的定量计算;双线型像质计的对比度传递函数近似符合二次曲线,经转换得到的调制传递函数值高于刀口法的测试值,刀口法计算数值偏低的原因在于运动不平稳所带来的不利影响。分析表明,数字射线扫描成像系统性能受到多个因素的共同影响,MTF测试结果可较全面地对影响因素进行定量评价,可用于确定最佳的检测参数或找出等价的参数组合。展开更多
基金supported by the National Natural Science Foundation of China(6140123261471200+4 种基金6150124861501254)the China Postdoctoral Science Foundation(2014M561692)the Jiangsu Province Postdoctoral Science Foundation(1402087C)the NUPTSF(NY213063)
文摘The in-phase and quadrature-phase imbalance (IQI) is one of the major radio frequency impairments existing in orthogonal frequency division multiplexing (OFDM) systems with direct-conversion transceivers. During the transmission of the communication signal, the impact of IQI is coupled with channel impulse responses (CIR), which makes the traditional channel estimation schemes ineffective. A decoupled estimation scheme is proposed to separately estimate the frequency-dependent IQI and wireless channel. Firstly, the generalized channel model is built to separate the parameters of IQI and wireless channel. Then an iterative estimation scheme of frequency-dependent IQI is designed at the initial stage of communication. Finally, based on the estimation result of IQI, the least square algorithm is utilized to estimate the channel-related parameters at each time of channel variation. Compared with the joint estimation schemes of IQI and channel, the proposed decoupled estimation scheme requires much lower training overhead at each time of channel variation. Simulation results demonstrate the good estimation performance of the proposed scheme.
基金Supported by The 2nd TCM Master Inheritance Studio Construction Project:2015,10Shaanxi Province famous TCM doctor Zhang Wei-hua Inheritance Studio Construction Project:2,019,022+2 种基金Academic Schools Inheritance Project of Shaanxi Provincial Administration of Traditional Chinese MedicineShaanxi Traditional Chinese Medicine[2018]no.40Key Research and Development project of Xianyang Science and Technology Bureau:2019K02-92Research innovation project of Xianyang Central Hospital:2019Q05。
文摘Objective:To observe the clinical improvement of Kāiqiàotōngluò(induce resuscitation and remove obstruction in meridians)acupuncture combined with repetitive transcranial magnetic stimulation(rTMS)in patients with hand dysfunction after stroke,and to provide evidence for its extensive application in the future.Methods:Sixty patients with the problem of hand dysfunction were divided into the observation group and the control group randomly.The two groups of patients were treated with the basic treatment,the observation group received Kdiqiaotongluo acupuncture combined with rTMS,and the control group only received the rTMS treatment.Broetz hand function scale,hemiplegic hand function grading,and modified Barthel index were used to evaluate the hand function of the patients in two groups before and after treatment.Results:After treatment,Broetz score of the patients in observation group and control group were significantly lower than that before treatment,and Broetz score of the patients in observation group was lower than that of control group(all P<0.05);As for the hemiplegic hand function grading,24 cases in the observation group improved,the improvement rate was 80.0%,and 8 cases in the control group improved,the improvement rate was only 26.7%.The improvement rate of observation group was significantly better than that of control group(P<0.01);the Barthel index scores of the observation group and the control group were significantly improved after treatment,and the observation group was better than the control group(both P<0.05).Conclusion:The Kāiqiàotōngluòacupuncture combined with rTMS can improve the hand dysfunction of patients after stroke,and it is worthy of clinical application.
文摘为有效实现数字射线扫描成像检测系统性能的定量分析评价,据此进行检测工艺参数的优化,对数字射线扫描成像检测系统调制传递函数(Modulation transfer function,MTF)进行了测试分析。采用刀口工具、双线型像质计、分辨率测试卡,对系统在不同焦点大小、放大倍数、运动方向的检测情况,分别进行了MTF的测试并进行了比较。结果表明,双线型像质计与分辨率测试卡的测试结果基本一致,但双线型像质计更便于对比度的定量计算;双线型像质计的对比度传递函数近似符合二次曲线,经转换得到的调制传递函数值高于刀口法的测试值,刀口法计算数值偏低的原因在于运动不平稳所带来的不利影响。分析表明,数字射线扫描成像系统性能受到多个因素的共同影响,MTF测试结果可较全面地对影响因素进行定量评价,可用于确定最佳的检测参数或找出等价的参数组合。
