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31.
利用某岩质边坡2002年-2011年的变形监测资料,结合区域地质与气象背景,运用莱茵达准则选定有效的监测数据,分别建立了GM(1,1)模型和趋势曲线预测模型;最后,基于最优加权组合原理,建立了边坡变形的最优加权组合模型。运用组合模型对该岩质边坡的变形进行了拟合和变形预测,模拟变形趋势与实际变形趋势对比结果表明,组合模型的预测精度高于任何单一模型的拟合精度,证明该组合模型合理、可靠。 相似文献
32.
Greenhouse gas (GHG) emissions (CO(2), CH(4)) from pilot-scale algal and duckweed-based ponds (ABP and DBP) were measured using the static chamber methodology. Daylight and nocturnal variations of GHG and wastewater characteristics (e.g. chemical oxygen demand (COD), pH) were determined via sampling campaigns during midday (12:30-15:30) and midnight (00:30-03:30) periods. The results showed that under daylight conditions in ABP median emissions were -232 mg CO(2) m(-2) d(-1) and 9.9 mg CH(4) m(-2) d(-1), and in DBP median emissions were -1,654.5 mg CO(2) m(-2) d(-1) and 71.4 mg CH(4) m(-2) d(-1), respectively. During nocturnal conditions ABP median emissions were 3,949.9 mg CO(2) m(-2) d(-1), 12.7 mg CH(4) m(-2) d(-1), and DBP median emissions were 5,116 mg CO(2) m(-2) d(-1), 195.2 mg CH(4) m(-2) d(-1), respectively. Once data measured during daylight were averaged together with nocturnal data the median emissions for ABP were 1,566.8 mg CO(2) m(-2) d(-1) and 72.1 mg CH(4) m(-2) d(-1), whilst for DBP they were 3,016.9 mg CO(2) m(-2) d(-) and 178.9 mg CH(4) m(-2) d(-1), respectively. These figures suggest that there were significant differences between CO(2) emissions measured during daylight and nocturnal periods (p < 0.05). This shows a sink-like behaviour for both ABP and DBP in the presence of solar light, which indicates the influence of photosynthesis in CO(2) emissions. On the other hand, the fluxes of CH(4) indicated that DBP and ABP behave as net sources of CH(4) during day and night, although higher emissions were observed from DBP. Overall, according to the compound average (daylight and nocturnal emissions) both ABP and DBP systems might be considered as net sources of GHG. 相似文献
33.
Bergmeir C García Silvente M Benítez JM 《Computer methods and programs in biomedicine》2012,107(3):497-512
In order to automate cervical cancer screening tests, one of the most important and longstanding challenges is the segmentation of cell nuclei in the stained specimens. Though nuclei of isolated cells in high-quality acquisitions often are easy to segment, the problem lies in the segmentation of large numbers of nuclei with various characteristics under differing acquisition conditions in high-resolution scans of the complete microscope slides. We implemented a system that enables processing of full resolution images, and proposes a new algorithm for segmenting the nuclei under adequate control of the expert user. The system can work automatically or interactively guided, to allow for segmentation within the whole range of slide and image characteristics. It facilitates data storage and interaction of technical and medical experts, especially with its web-based architecture. The proposed algorithm localizes cell nuclei using a voting scheme and prior knowledge, before it determines the exact shape of the nuclei by means of an elastic segmentation algorithm. After noise removal with a mean-shift and a median filtering takes place, edges are extracted with a Canny edge detection algorithm. Motivated by the observation that cell nuclei are surrounded by cytoplasm and their shape is roughly elliptical, edges adjacent to the background are removed. A randomized Hough transform for ellipses finds candidate nuclei, which are then processed by a level set algorithm. The algorithm is tested and compared to other algorithms on a database containing 207 images acquired from two different microscope slides, with promising results. 相似文献
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谐振式光纤陀螺全数字闭环方案 总被引:2,自引:1,他引:2
谐振式光纤陀螺是一种新型的惯性传感仪器,与传统机械陀螺和其他光学陀螺相比具有很多理论上的优势.数字信号处理电路的谐振式光纤陀螺全数字闭环是采用双频率数字锯齿波相位调制技术对光路进行了相应的调制和解调.对光信号中夹杂的大量白噪声以及数字信号处理中由于有限位数的A/D引入的量化噪声进行综合考虑,提出了用比信号带宽高很多的采样率对含有噪声的信号进行过采样,加上后续的数字信号处理,低位数A/D和高位数A/D的检测效果几乎一样.数字调制的精度影响了系统的精度,使用平均法用低位的D/A可以实现很大的调制动态范围.经过基于文中设计的数字系统的实验,得到了和理论仿真类似的解调曲线,证明了文中提出的数字闭环方案的可行性. 相似文献
38.
文章通过探讨自动化专业教学当前面临的机遇和挑战,阐述了自动化专业毕业设计教学实践中的一些研究思路和实践方法,以适应新形势下对自动化专业毕业生的要求。 相似文献
39.
分析了单个神经元神经网络(即感知器)的结构特征;介绍了自顶向下的FPGA的设计方法,并在QUARTUS^TM Ⅱ软件平台上实现了单个神经元的硬件神经网络. 相似文献
40.
介绍了采用可编程控制器(PLC)对加氢装置高速增压泵联锁控制系统进行改造的设计与实现过程,并对其中的关键设计思想和实现程序作了论述.同时对信号处理和注意事项进行了讨论. 相似文献