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排序方式: 共有359条查询结果,搜索用时 15 毫秒
1.
TlBr晶体是一种理想的的X射线和γ射线探测器材料,其原子序数高、密度大、禁带宽和电离能小,TlBr探测器具有探测效率高、能量分辨性能优异和体积小易集成等特点,可以在室温条件下使用,是核材料核查与核保障、国土安全、空间及高能物理实验的较佳选择。文章介绍了TlBr探测器工作原理及其发展与现状,对探测器结构设计及信号收集处理方法作了详细介绍,提出了TlBr探测器发展及开发工艺的建议。 相似文献
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《Measurement》2014
The determination of errors generated by systems measuring dynamically changeable signals presents a difficult problem due to their unknown shape and the measurement duration. This paper presents a proposed solution to this problem by means of the signals maximizing chosen error criterion. Thus, it refers to the commonly applied methods for determining the accuracy class of systems intended for the measurement of static quantities.The method of determining a signal with one constraint, maximizing integral-square error, is discussed in this paper in detail. As an example, four acceleration sensors are considered and the maximizing signals from the range of one to twenty-five switchings are determined. It is worth underlining that the paper presents a solution obtained by an analytical method instead of using optimization methods, the application of which is necessary in the case of signals with an increased number of constraints. 相似文献
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置换混叠图像盲分离作为一类新型的单信道盲分离,在理论和方法上与传统的单信道盲分离有着本质的不同。针对一类置换区域含噪声的置换混叠图像,本文提出一种基于噪声检测的置换混叠图像盲分离算法。本文首先给出置换混叠图像的数学模型,对置换混叠图像用非零元个数约束的K-SVD算法进行训练得到其稀疏表示的字典,利用学习得到的字典对置换混叠图像去噪,然后利用去噪后的置换混叠图像与原图像作差运算得到差图像,通过检测差图像来确定出置换区域的位置和大小。并利用图像形态学运算优化置换区域,采用阈值化操作分离出置换图像。实验结果表明,本文算法能够较好的从置换混叠图像中分离出置换图像,并且不受置换图像的大小、位置、个数和置换图像所含噪声大小的影响。 相似文献
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模糊提升小波在脉冲漏磁信号处理中的应用 总被引:1,自引:0,他引:1
在脉冲漏磁检测中,有效抑制信号中的噪声是最终正确识别缺陷的关键环节之一.介绍了提升小波变换的基本理论及传统阈值降噪方法;针对传统硬、软阈值法的局限性,提出了包括带有可变因子的隶属函数的模糊阈值处理方法;运用该方法对仿真和实验信号进行了降噪研究.结果表明,采用模糊提升小波降噪方法能够很好的抑制脉冲漏磁信号中的噪声,在实时... 相似文献
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We present a novel way to design self-assembling systems using a notion of signal (or ray) akin to what is used in analyzing the behaviour of cellular automata. This allows purely geometrical constructions, with a smaller specification and easier analysis. We show how to design a system of signals for a given set of shapes, and how to transform these signals into a set of tiles which self-assemble into the desired shapes. 相似文献
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Wajid Aziz Taher Biala Nazneen Habib Muhammad Saleem Abbasi Michael P. Wailoo Fernando S. Schlindwein 《Measurement》2013
Intrauterine growth restricted (IUGR) individuals have greater predisposition to develop a metabolic syndrome in later life manifesting itself as obesity, hypertension, type 2 diabetes or cardiovascular disease. Poor fetal growth may alter the regularity mechanism of cardiac autonomic system that is involved in the development of these diseases. The malfunctioning of the cardiac autonomic system assessed by decrease in heart rate variability (HRV) is associated with negative cardiovascular outcomes. This study is aimed at investigating the risk of development of coronary heart disease in IUGR children in later life. For that purpose HRV analysis of normal and growth restricted children was performed during sleep and wake stages. The study group consisted of 9–10 years old, 32 normal, 20 low birth weight IUGR children. The standard time domain HRV metrics (mean RR, SDNN, RMSSD, NN50 and pNN50) and Poincaré indices (SD1 and SD2) were used to analyse and compare the RR-interval time series of these groups. The IUGR children showed lower HRV as compared with normal children during both sleep and wake stages. The significantly decreased HRV during sleep provide an evidence of autonomic derangement that may be associated with higher risk of lethal arrhythmias in the IUGR children in later life. 相似文献