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用于电磁法观测系统开机自检的信号发生器实现方法 被引量:1
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作者 严发宝 柳建新 +2 位作者 苏艳蕊 韦艳刚 郑翾宇 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2017年第11期4341-4351,共11页
针对电磁法观测系统在使用过程中的开机自检要求,分析常用测量系统及地球物理仪器的检测信号特征,通过对已有机制进行研究和对比,结合现有信号产生电路的优势,提出一种功耗低、精度高、设计简单的自检信号发生器实现方案.基于该方案设... 针对电磁法观测系统在使用过程中的开机自检要求,分析常用测量系统及地球物理仪器的检测信号特征,通过对已有机制进行研究和对比,结合现有信号产生电路的优势,提出一种功耗低、精度高、设计简单的自检信号发生器实现方案.基于该方案设计了一套实现电路,其以CPLD为核心,由精密参考电压源、模拟开关及运算放大器等器件构成,并对该电路进行仿真与测试.通过系统稳定性分析,采用波特图与奈奎斯特图表明信号发生电路的稳定性符合设计要求.经仿真与测试,能够通过换挡开关产生幅值为20μV~2 V、频率范围在1 Hz~100 kHz的自检脉冲信号,频率稳定在1%,重复测试相位稳定度小于1.5%,幅值误差可以优化到1%以内,且能通过其稳定的谐波分量来获取该系统带宽更宽的通道测试响应.测试结果表明,该自检信号发生器电路实际功耗小于0.3 W,20μV~2 V幅值范围和1 Hz~100 kHz频率范围内性能指标的测量结果和仿真结果相符,并成功应用于某监控系统.利用该信号发生器电路实现自检具有操作方便、成本低、易于设计等优点,能够有效的弥补其它自检模式的缺陷. 展开更多
关键词 观测系统 自检信号 低功耗 CPLD
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通道幅相不一致的实时校正方法 被引量:8
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作者 司伟建 初萍 孙圣和 《系统工程与电子技术》 EI CSCD 北大核心 2011年第10期2179-2183,共5页
针对空间谱估计算法性能对通道幅相不一致敏感的问题,根据实际测向系统接收通道的特点,提出了利用自检信号进行实时校正的方法,将整个通道的校正分为天线到接收通道之间的无源器件预校正和接收通道的实时校正两个部分,先利用0°入... 针对空间谱估计算法性能对通道幅相不一致敏感的问题,根据实际测向系统接收通道的特点,提出了利用自检信号进行实时校正的方法,将整个通道的校正分为天线到接收通道之间的无源器件预校正和接收通道的实时校正两个部分,先利用0°入射信号和自检信号的接收数据计算得到预校正矩阵,在测向过程中利用自检信号对接收通道进行实时校正。Matlab仿真结果表明实时校正方法可以动态校正通道的幅相不一致误差并且有利于提高MUSIC算法的分辨力,实测数据也表明实时校正方法可以动态的校正通道幅相不一致误差达到提高测向精度的目的。 展开更多
关键词 测向系统 实时校正 幅相不一致 自检信号 MUSIC算法
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深水地震拖缆数据采集仪器的质量控制方法 被引量:2
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作者 黄龙君 张建峰 +4 位作者 胡勇 于强 刘延旭 马晓伟 赵凯迪 《电子测量技术》 北大核心 2021年第10期144-148,共5页
针对深水地震拖缆长缆多道问题,提出一种采集仪器的质量控制方法。该方法通过主动与被动两种模式来实现,包含室内系统运行质量控制方法和水下拖缆数据采集质量控制方法。其中主动模式可以按需产生模拟或数字激励信号送至采集仪器,从而... 针对深水地震拖缆长缆多道问题,提出一种采集仪器的质量控制方法。该方法通过主动与被动两种模式来实现,包含室内系统运行质量控制方法和水下拖缆数据采集质量控制方法。其中主动模式可以按需产生模拟或数字激励信号送至采集仪器,从而用于评价仪器关键性能参数指标;被动模式则可实时采集仪器运行过程中的各种状态参数,用以实现仪器运行质量的实时评估。基于该独立于采集仪器的完备质量控制方法,可以有效控制采集仪器的质量,保障数据采集的品质,极大地降低了勘探作业的风险。长期的实验室测试和海洋作业的结果均表明了该方法的正确性和可实现性。 展开更多
关键词 海洋物探 数据采集仪器 质量控制 自检信号 实时监控
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Traffic light detection and recognition in intersections based on intelligent vehicle
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作者 张宁 何铁军 +1 位作者 高朝晖 黄卫 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期517-521,共5页
To ensure revulsive driving of intelligent vehicles at intersections, a method is presented to detect and recognize the traffic lights. First, the stabling siding at intersections is detected by applying Hough transfo... To ensure revulsive driving of intelligent vehicles at intersections, a method is presented to detect and recognize the traffic lights. First, the stabling siding at intersections is detected by applying Hough transformation. Then, the colors of traffic lights are detected with color space transformation. Finally, self-associative memory is used to recognize the countdown characters of the traffic lights. Test results at 20 real intersections show that the ratio of correct stabling siding recognition reaches up to 90%;and the ratios of recognition of traffic lights and divided characters are 85% and 97%, respectively. The research proves that the method is efficient for the detection of stabling siding and is robust enough to recognize the characters from images with noise and broken edges. 展开更多
关键词 intelligent vehicle stabling siding detection traffic lights detection self-associative memory light-emitting diode (LED) characters recognition
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电视导引头跟踪性能自动测试系统设计
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作者 唐尧 秦开宇 《自动化信息》 2006年第11期68-69,67,共3页
跟踪性能自动测试系统是一种电视导引头的专用测试设备,它的主要作用是对电视导引头的各项功能和技术指标进行测试。本文对测试系统的组成和总体结构进行了分析,介绍了软硬件设计方法。同时,提出了开放式结构和多线程两个关键技术。... 跟踪性能自动测试系统是一种电视导引头的专用测试设备,它的主要作用是对电视导引头的各项功能和技术指标进行测试。本文对测试系统的组成和总体结构进行了分析,介绍了软硬件设计方法。同时,提出了开放式结构和多线程两个关键技术。经使用证明,该系统工作可靠,其性能完全满足设计要求。 展开更多
关键词 自动测试系统 信号自检 开放式结构 视频跟踪性能
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Automatically detecting auditory P300 in several trials 被引量:1
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作者 莫少锋 汤井田 陈洪波 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2201-2206,共6页
A method was demonstrated based on Infomax independent component analysis(Infomax ICA) for automatically extracting auditory P300 signals within several trials. A signaling equilibrium algorithm was proposed to enhanc... A method was demonstrated based on Infomax independent component analysis(Infomax ICA) for automatically extracting auditory P300 signals within several trials. A signaling equilibrium algorithm was proposed to enhance the effectiveness of the Infomax ICA decomposition. After the mixed signal was decomposed by Infomax ICA, the independent component(IC) used in auditory P300 reconstruction was automatically chosen by using the standard deviation of the fixed temporal pattern. And the result of auditory P300 was reconstructed using the selected ICs. The experimental results show that the auditory P300 can be detected automatically within five trials. The Pearson correlation coefficient between the standard signal and the signal detected using the proposed method is significantly greater than that between the standard signal and the signal detected using the average method within five trials. The wave pattern result obtained using the proposed algorithm is better and more similar to the standard signal than that obtained by the average method for the same number of trials. Therefore, the proposed method can automatically detect the effective auditory P300 within several trials. 展开更多
关键词 independent component analysis (ICA) auditory P300: fixed temporal patltern several trials event-related potentials
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Colometer:A real-time quality feedback system for screening colonoscopy 被引量:2
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作者 Dobromir Filip Xuexin Gao +5 位作者 Leticia Angulo-Rodriguez Martin P Mintchev Shane M Devlin Alaa Rostom Wayne Rosen Christopher N Andrews 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第32期4270-4277,共8页
AIM:To investigate the performance of a new software-based colonoscopy quality assessment system.METHODS:The software-based system employs a novel image processing algorithm which detects the levels of image clarity,w... AIM:To investigate the performance of a new software-based colonoscopy quality assessment system.METHODS:The software-based system employs a novel image processing algorithm which detects the levels of image clarity,withdrawal velocity,and level of the bowel preparation in a real-time fashion from live video signal.Threshold levels of image blurriness and the withdrawal velocity below which the visualization could be considered adequate have initially been determined arbitrarily by review of sample colonoscopy videos by two experienced endoscopists.Subsequently,an overall colonoscopy quality rating was computed based on the percentage of the withdrawal time with adequate visualization(scored 1-5;1,when the percentage was 1%-20%;2,when the percentage was 21%-40%,etc.).In order to test the proposed velocity and blurriness thresholds,screening colonoscopy withdrawal videos from a specialized ambulatory colon cancer screening center were collected,automatically processed and rated.Quality ratings on the withdrawal were compared to the insertion in the same patients.Then,3 experienced endoscopists reviewed the collected videos in a blinded fashion and rated the overall quality of each withdrawal(scored 1-5;1,poor;3,average;5,excellent) based on 3 major aspects:image quality,colon preparation,and withdrawal velocity.The automated quality ratings were compared to the averaged endoscopist quality ratings using Spearman correlation coefficient.RESULTS:Fourteen screening colonoscopies were assessed.Adenomatous polyps were detected in 4/14(29%) of the collected colonoscopy video samples.As a proof of concept,the Colometer software rated colonoscope withdrawal as having better visualization than the insertion in the 10 videos which did not have any polyps(average percent time with adequate visualization:79% ± 5% for withdrawal and 50% ± 14% for insertion,P < 0.01).Withdrawal times during which no polyps were removed ranged from 4-12 min.The median quality rating from the automated system and the reviewers was 3.45 [interquartile range(IQR),3.1-3.68] and 3.00(IQR,2.33-3.67) respectively for all colonoscopy video samples.The automated rating revealed a strong correlation with the reviewer's rating(ρ coefficient= 0.65,P = 0.01).There was good correlation of the automated overall quality rating and the mean endoscopist withdrawal speed rating(Spearman r coefficient= 0.59,P = 0.03).There was no correlation of automated overall quality rating with mean endoscopists image quality rating(Spearman r coefficient= 0.41,P = 0.15).CONCLUSION:The results from a novel automated real-time colonoscopy quality feedback system strongly agreed with the endoscopists' quality assessments.Further study is required to validate this approach. 展开更多
关键词 Colonoscopy Quality assurance Quality improvement Withdrawal time Colon cancer Bowel preparation
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企业无线调车设备机车控制器故障报警现象的分析与解决
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作者 于晓溪 张景君 《冶金设备》 2014年第S1期191-193,共3页
针对冶金企业在使用铁路平面无线调车设备作业中最常出现的机车控制器故障报警现象进行了比较详细的分析,给出了行之有效的解决方案和使用注意事项。并分析了无线调车设备的发展方向和数字型无线调车设备的优点。
关键词 铁路平面无线调车设备 机车控制器 故障报警 自检信号 电磁屏蔽
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Single Channel Fetal ECG Detection Using LMS and RLS Adaptive Filters 被引量:1
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作者 Alaa Aldoori Ali Buniya ZHENG Zheng 《Chinese Journal of Biomedical Engineering(English Edition)》 CSCD 2015年第4期166-178,共13页
ECG is an important tool for the primary diagnosis of heart diseases, which shows the electrophysiology of the heart. In our method, a single maternal abdominal ECG signal is taken as an input signal and the maternal ... ECG is an important tool for the primary diagnosis of heart diseases, which shows the electrophysiology of the heart. In our method, a single maternal abdominal ECG signal is taken as an input signal and the maternal P-QRS-T complexes of original signal is averaged and repeated and taken as a reference signal. LMS and RL5 adaptive filters algorithms are applied. The results showed that the fetal ECGs have been successfully detected. The accuracy of Daisy database was up to 84% of LM5 and 88% of RLS while PhysioNet was up to 98% and 96% for LMS and RLS respectively. 展开更多
关键词 single channel fetal ECG maternal ECG pan Tompkins adaptive filters
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