排序方式: 共有11条查询结果,搜索用时 203 毫秒
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随着电力系统智能化水平的不断提高,电网中产生的数据体系也越来越庞大,而数据的质量会直接影响电力系统的运行分析和规划决策。文中基于数据挖掘技术提出一种电网时序数据质量维护体系,筛选不合格的数据,并确定数据所存在的问题,为分析出现问题的原因提供便利。对电力数据及传输过程进行了分析,并指出了可能存在的问题。不同地区的数据具有自身不同的特点,为了提高检测速度,基于决策树算法先对历史数据样本进行决策分析。以某地区的数据训练集为例,对该地区电力数据检测流程进行分析,得到适合该区的检测顺序。针对数据合理性难以检测的问题,利用基于聚类的离群检测法筛选出问题数据,并尝试分析问题数据产生原因。通过算例证明了所提时序数据质量维护流程的有效性和可靠性。 相似文献
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为满足航天高声压160dB噪声测量的需求,使用ICP型噪声传感器进行测量,针对ICP型噪声传感器工作条件及其输出信号,设计一种调理电路。利用LM134同时实现ICP型噪声传感器恒流和高压激励的工作条件,通过轨到轨运放AD824完成对ICP型噪声传感器输出信号的放大、滤波、跟随等以达到采集系统需要的0~5 V电压信号。在130 dB^160 dB噪声下,ICP型噪声传感器与调理电路配合标定相对误差<1%,该调理电路可以与ICP型噪声传感器很好地配合使用。 相似文献
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Wireless Personal Communications - The emergence and development of cloud computing technology has brought changes in audit thinking and auditing technology and methods. However, there is still a... 相似文献
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Cerenkov luminescence imaging(CLI) is a relatively new optical molecular imaging technique. The nature of Stokes shift in quantum dots(QD) can be used to improve the quality of CLI. However, the interaction mechanism of QD with Cerenkov light remains unclear. In this work, the interaction mechanism between QD and radionuclides emitting β rays, γ rays, and Cerenkov light was investigated. The 96-well plates were used to test the different levels of radioactivity of radionuclides with different QD concentrations. Transparent vials were used to determine the relationship between QD fluorescence intensity and the distance from QD to the radionuclide. In addition, black paper was used to block the transmission of Cerenkov light through the QD vials. A linear relationship was found between the number of photons and the radioactivity of radionuclides when the QD concentration was kept constant. Similarly, the number of photons was linearly related to the QD concentration when the radioactivity of radionuclides was kept constant. Furthermore, with the increases in the distance between radionuclides and quantum dots, the number of photons was exponentially decreased. Meanwhile, the number of photons emitted from QD excited by Cerenkov light accounted for 20% the total number of photons excited by 131 I radionuclide. The result proved that QD was not only excited by Cerenkov light but also by other rays. 相似文献
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当前常用3维重构的方法表示和计算视频中的人体位姿,但由于这些方法通常需要多个摄像头,不仅限制条件多,且计算复杂度高,为此,提出了一种基于头肩分割的人体位姿估计算法。该算法首先对视频中的人体进行头肩定位;然后利用人体头部的平面成像特点计算头部位姿,同时利用人体肩部的轮廓变化特点计算躯干位姿;最后结合头部和躯干的位姿估计运动中的人体位姿。实验结果证明,该算法是有效和优越的。 相似文献
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Wen Qiao Chinhua Wang Zengqian Ding Junlan Song XiaoXiao Wei Yu-Hwa Lo 《Microfluidics and nanofluidics》2016,20(5):77
Sample purification and enrichment is an important and usually time-consuming step for on-chip nucleic acid detection and analysis. This paper presents an electrophoretic DNA focusing method in microfluidic devices to enrich nucleic acid concentration by around 2700-fold. The electrical waveforms applied to five individual electrodes are such designed that DNAs move successively to the collection electrodes at high speed, while the interferences from bubbles due to electrohydrolysis are minimized. In a spiral channel with a total length of 48 cm, 1 ml DNA sample is purified and enriched by 57 times at a flow rate of 30 μl/min at first. The captured DNAs are then released and transported to the second microfluidic chamber where DNAs are collected and concentrated by 49 times. Thus, in about 40 min, the two-stage device can extract DNAs from 1 ml sample volume and enrich its concentration by 2790-fold. A trade-off exists between the process throughput and the DNA collection efficiency. A DNA capture efficiency of 99.7 % is reached when the flow rate is 1 μl/min, and the maximum DNA capture throughput is achieved at a flow rate of 30 μl/min. As a platform technology, the device can be integrated into bio-sensing and genetic analysis assays for DNA extraction and pre-concentration. 相似文献
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This paper presents the construction of Chinese hybrid radiation adult phantoms,which are compatible with anatomical parameters for the Chinese reference population.The phantoms were designed using polygonal mesh surface,which makes the phantom more flexible and realistic than previous generations.Voxelization of hybrid phantoms was performed to adopt Monte Carlo methods.External dose coefficients were calculated by Geant4 and compared to the ICRP reference phantom.The results show that the organ dose is different from ICRP116 with the low energy photons,which can be ascribed to the anatomy and topology difference of each organ.The effective dose of CHRAP is 19%higher than ICRP 116 in the energy range from10 to 100 keV and is almost the same in the energy range from 100 keV to 10 MeV.These phantoms can be used as the basic phantom to adjust the posture or organ volume to estimate dosimetry in medical and space explorations. 相似文献
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经过近3个月的筹备,江苏省工商业联合会玩具业商会7月15日成立,来自全省各地的100多家会员单位负责人及10多家玩具经营企业代表出席了大会。大会经过选举,扬州雅伦玩具有限公司董事长兼总经理林若庸当选为会长。 相似文献
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