关键词： 最小方差无畸变响应   离散傅里叶变换   盲源分离   MVDR算法   来波方向   频谱分量   谱估计   数据处理  

摘要： 针对单线阵左右舷模糊问题,提出了结合盲源分离的非直单线阵多目标左右舷分辨算法。该算法首先通过离散傅里叶变换将阵列接收信号离散化为若干个窄带频谱分量,之后对每个频点的窄带数据讲行盲源分离,得到每个频点上各个来波信号的导向向量;然后通过常规波束形成对各个导向向量进行方位谱估计,并根据左右舷抑制比进行单目标左右舷分辨,确定各个频点上的来波方向;最后对所有频点上的来波方向进行聚类,得到各个真实目标的方位,从而实现多目标左右舷分辨。仿真实验中,相比常规波束形成方法(CBF)和最小方差无畸变响应算法(MVDR),该算法更准确地估计出了目标数目,且保持了较快的计算速度;海试数据处理中,该算法排除了目标镜像的干扰,准确估计出了船只目标的轨迹。仿真及海试数据处理均表明,该算法可以分辨真实目标与目标镜像,具有比CBF和MVDR算法更好的左右舷分辨能力。

关键词： Missing data   Interpolation   Backpropagation neural network   Breast cancer   Improvement  

摘要： Background: A complete dataset is essential for biomedical implementation. Due to the limitation of objective or subjective factors, missing data often occurs, which exerts uncertainty in the subsequent data processing. Commonly used methods of interpolation are interpolating substitute values that keep minimum error. Some applications of statistics are usually used for handling this problem. Methods: We are trying to find a higher performance interpolation method compared with the usual statistic methods, by using artificial intelligence which is in full swing today. The prediction and classification of backpropagation neural network are used in this paper, describes a missing data interpolation method to propose the interpolation model that mines association rules in the data. In the experiment, depending on a multi-layer network structure, the model is trained and tested by sample data, constantly revises network weights and thresholds. The error function decreases along the negative gradient direction and approaches the expected real output. The model is validated on the breast cancer dataset, and we select real samples from the data set for validation, moreover, add four traditional methods as a control group. Results: The proposed method has great performance improvement in the interpolation of missing data. Experimental results show that the interpolation accuracy of our proposed method (84%) is higher than four traditional methods (1.33%, 74.67%, 73.33%, 77.33%) as mentioned in this paper, BPNN stays low in MSE evaluation. Finally, we analyze the performance of various methods in processing missing data. Conclusions: The study in this paper has estimated missing data with high accuracy as much as possible to reduce the negative impact in the diagnosis of real life. At the same time, it can also assist in missing data processing in the biomedical field. (C) 2021 AGBM. Published by Elsevier Masson SAS. All rights reserved.

关键词： 遥感图像   图像处理  

ISBN: (纸本)9787563565856

摘要： 本书主要介绍遥感高光谱图像压缩与融合技术的基本概念、原理和常用算法及创新算法，并进行了实验验证、比较分析及评价，探讨了高光谱图像应用于矿产资源评价模型的研究。本书内容包括4篇。第1篇（第1-4章）为遥感高光谱图像基础知识，论述了遥感的概念、高光谱图像的基本特征、书中所做实验的数据以及实验平台、高光谱图像压缩基本原理和融合基本技术。第2篇（第5-10章）论述了遥感高光谱图像压缩技术，如基于降维的压缩算法、基于预测的无损压缩算法、基于变换的压缩算法、基于矢量量化的压缩算法以及基于分布式编码的无损压缩算法，同时

ISBN: (纸本)9787030698667

关键词： Fuchs endothelial corneal dystrophy   Corneal endothelium   PARP   Oxidate damage   Apoptosis  

摘要： Fuchs endothelial corneal dystrophy (FECD) is one of the main causes for corneal endothelial blindness, which is characterized by the progressive decline of corneal endothelial cells. Poly (ADP-ribose) polymerase (PARP) was reported to be involved in cell death and apoptosis of several diseases. However, the role of PARP1 in the progression of FECD remains elusive. In the present study, we reported that UVA irradiation caused the corneal endothelial damage and corneal edema in mice, which was accompanied with the elevated activity of PARP1 and PAR. The PARP1 inhibitor PJ34 resolved the corneal edema and protected corneal endothelium from UVA-induced oxidative damage, mitochondrial dysfunction, and cell apoptosis. Mechanistically, PARP1 inhibition exerted its anti-apoptotic effects through downregulation of the phosphorylation levels of JNK1/2 and p38 MAPK and subsequently the increase of MKP-1. Our results suggest that PARP1 inhibition protects corneal endothelium from UVA-induced oxidative damage, which provides a potential alternative strategy for the therapy of FECD.

ISBN: (纸本)9787519862091

关键词： Numerical models   Data models   Analytical models   Soil   Geology   Solid modeling   XML   Borehole data   data processing platform (DPP)   grid ground model   numerical simulation  

摘要： There have been attempts to improve the operational efficiency of construction projects and plan response countermeasures for estimated damage following disasters through the utilization of accumulated electronic data, which constructs a digital twin that can reproduce a physical space in cyberspace and feedback the cyberspace simulation results to physical space. However, the application of such simulations is limited, unless numerical models can be automatically constructed from the data. In this study, we develop a program that utilizes a data processing platform to read, transform, and integrate data to create mediated data with a common data structure. This mediated data can be used to construct analytical models for various numerical analyses. Using the program developed, a grid model of 3-D ground surface as the mediated data was constructed based on borehole data obtained through a ground survey. Each grid point has basic material parameters of soil, and these parameters are estimated from borehole data and other investigation reports. Each grid point has general geotechnical parameters and can be easily converted to a 3-D finite-element model. When the borehole data is added or changed, the analytical model can be updated with almost no cost, whereas it would be very costly to create the model manually.

关键词： Detrital zircons geochronology   U-Pb   Software   Data filtering   Data visualizing   Data export  

摘要： Overwhelming numbers of detrital zircon (dZr) U-Pb ages have been acquired all over the globe in the last few decades, opening new horizons for employing big data approaches. However, several impediments such as frequent publication of heavily filtered data tables with omitted analyses, failure to cite the logic on "best age" computation, and generally the lack of uniformity among data treatment approaches delay the employment of this growing volume of data to the full extent. We have developed Dezirteer software to address some of the impediments. The program runs on any OS as a Python package and can be installed in Windows via an executable installer. Dezirteer imports U-Th-Pb LA-ICPMS geochronology data (either as .csv files from Iolite or Glitter, or from a manually-filled template). First, it allows the user to define and apply filters (by elevated discordance, analytical uncertainty, and U concentration). Next, the user defines computations (discordance calculation, type of Pb-correction, choosing "best age"), and Dezirteer applies them on dZr datasets. Finally, Dezirteer exports data and manipulations on them, unequivocally separated. Dezirteer permits to quickly assess the results of filters and computations visually (concordia, probability density curves, kernel density estimates, histograms, and cumulative diagrams) and numerically (Kolmogoroff - Smirnov statistics, Likeness, and Similarity coefficients, peaks locations). Thus, our program can be used as a substitute for several existing software packages and provides some unique functionality. We propose several guidelines for publishing U-Th-Pb dZr data to increase the data's trustworthiness and usability and improve the transparency of manipulations on these data. Most importantly, dZr data must be published before extensive filtering and interpretation, while all further filtering and computational aspects should be described. Such an approach will significantly simplify the use of global dZr data by

关键词： water quality testing   quality control   matters needing attention  

摘要： With the continuous improvement of water quality requirements of Chinese residents, the state and relevant departments began to gradually pay attention to the quality control of water quality monitoring and evaluation for this work. In this paper, various factors affecting the actual work of water quality monitoring are defined, the optimization method in the specific link of water quality testing is analyzed, and the specific precautions in the quality assessment of water quality testing are put forward to improve the quality control ability of water quality testing institutions, so as to ensure the stability and reliability of the testing results.