On the Purely Longitudinal Space Charge Wave of an Extended Electromagnetic Theory

An extended electromagnetic theory has earlier been developed, as being based on the hypothesis of a nonzero electric field divergence in vacuo and the requirement of Lorentz invariance. This basis is supported by the commonly accepted fact that the vacuum is not merely an empty space, but has a ground state of nonzero energy and can become electrically polarized. The vacuum is thereby considered as electrically polarizable in the sense of being capable of supporting charge motion in the form of, e.g., space-charge waves. One result of the dynamic states of the present theory is the prediction of a purely longitudinal electric space-charge wave (S-wave) having no induced magnetic field. The behaviour of this wave type is demonstrated for a number of geometrical configurations. Some preliminary proposals are finally made for generation and detection of S waves. These waves are expected to have features which differ from those of the conventional transverse electromagnetic waves. If the S wave would come out to be physically realizable, it may thus form the basis of a new principle for telecommunication without or with very small magnetic induction effects.     

凹面光栅衍射效率测量值的影响因素及补偿方法研究

通过仪器获得的凹面光栅的衍射效率是相对值,其测量值的精度受测量过程和补偿方法的影响。为使效率测量值的测量精度得到进一步提高,有必要对测量值产生影响的主要因素进行深入研究。该文进一步考察了影响衍射效率测量精度的主要因素,针对待测凹面光栅根据待测波长的测试要求进行旋转造成光束截面变化而产生的问题,适当补充原理性方案,并在此基础上推导出了适用于凹面光栅的光束截面变化因子k(θ)的解析表达式。基于影响测量精度因素与理论值之间的非线性关系,提出采用二次非线性回归分析的方法对测量结果进行补偿,给出了提高衍射效率测量精度的补偿公式。实验结果表明,对光栅衍射效率的测量值进行进一步补偿后,使得补偿值与理论值之间的整体误差范围由±2.5%缩小为±0.3%以内,与线性回归分析方法相比,显著缩小了补偿值与理论值之间的差距,进一步保证了衍射效率的准确测量。将补偿过程嵌入测量程序,该方法能够实时补偿测量结果,满足仪器准确测量的要求。     

单极巨共振的相对论平均场计算

利用最近完成的相对论平均场理论的计算程序,研究了原子核单极巨共振.计算了¹⁶O,⁴⁰Ca和²⁰⁸Pb的同位旋标量和同位旋矢量单极巨共振.得到的结果与实验符合较好.     

基于相对论平均场理论对超重核冷熔合反应截面的研究

在形变约束的相对论平均场理论框架下计算了合成Z=102—118元素的(可能)冷熔合反应中复合核及蒸发一或两个中子剩余核的位能曲面,得到了复合核和剩余核平衡点和鞍点的性质、静态裂变垒高度和冷熔合反应的最佳入射能;利用壳修正和对修正方法计算了平衡点和鞍点的壳修正能、对修正能和微观能.利用由此得到的壳结构信息,用简单的熔合蒸发唯象模型计算了相应反应的冷熔合截面.结果发现,TM1参数提供的结构性质给出了与实验接近的反应截面.     

CSR实验环电子冷却装置的纵向电子束温度

电子冷却装置中, 电子束纵向温度是计算冷却力的主要参量之一. 当电子与被冷却离子的相对速度很小时, 纵向冷却力与离子速度呈线性关系, 并且线性区域的宽度与电子束纵向温度有关. 通过分析影响电子束纵向温度的主要因素, 得到了兰州重离子冷却储存环实验环(CSRe)电子冷却装置中电子束纵向温度的大小.     

Effects of Tau and Sampling Frequency on the Regularity Analysis of ECG and EEG Signals Using ApEn and SampEn Entropy Estimators

Electrocardiography (ECG) and electroencephalography (EEG) signals provide clinical information relevant to determine a patient’s health status. The nonlinear analysis of ECG and EEG signals allows for discovering characteristics that could not be found with traditional methods based on amplitude and frequency. Approximate entropy (ApEn) and sampling entropy (SampEn) are nonlinear data analysis algorithms that measure the data’s regularity, and these are used to classify different electrophysiological signals as normal or pathological. Entropy calculation requires setting the parameters r (tolerance threshold), m (immersion dimension), and τ (time delay), with the last one being related to how the time series is downsampled. In this study, we showed the dependence of ApEn and SampEn on different values of τ, for ECG and EEG signals with different sampling frequencies (F_s), extracted from a digital repository. We considered four values of F_s (128, 256, 384, and 512 Hz for the ECG signals, and 160, 320, 480, and 640 Hz for the EEG signals) and five values of τ (from 1 to 5). We performed parametric and nonparametric statistical tests to confirm that the groups of normal and pathological ECG and EEG signals were significantly different (p < 0.05) for each F and τ value. The separation between the entropy values of regular and irregular signals was variable, demonstrating the dependence of ApEn and SampEn with F_s and τ. For ECG signals, the separation between the conditions was more robust when using SampEn, the lowest value of F_s, and τ larger than 1. For EEG signals, the separation between the conditions was more robust when using SampEn with large values of F_s and τ larger than 1. Therefore, adjusting τ may be convenient for signals that were acquired with different F_s to ensure a reliable clinical classification. Furthermore, it is useful to set τ to values larger than 1 to reduce the computational cost.     

Status Forecasting Based on the Baseline Information Using Logistic Regresssion

In the status forecasting problem, classification models such as logistic regression with input variables such as physiological, diagnostic, and treatment variables are typical ways of modeling. However, the parameter value and model performance differ among individuals with different baseline information. To cope with these difficulties, a subgroup analysis is conducted, in which models’ ANOVA and rpart are proposed to explore the influence of baseline information on the parameters and model performance. The results show that the logistic regression model achieves satisfactory performance, which is generally higher than 0.95 in AUC and around 0.9 in F1 and balanced accuracy. The subgroup analysis presents the prior parameter values for monitoring variables including SpO2, milrinone, non-opioid analgesics and dobutamine. The proposed method can be used to explore variables that are and are not medically related to the baseline variables.     

激光雷达数据应用于海气界面气体传输速率的估算

选取2007年1、4、7、10月4个月夜间无云的云-气溶胶激光雷达和红外探测者观测卫星(CALIPSO)星载激光雷达Version 3.01数据,提取532nm激光海面后向散射系数并计算海面波浪均方斜率。同时选用准同步AMSR-E海面风速数据,利用Wanninkhof等于2009年提出的包含线性、平方、立方项的海面风速与气体传输速率混合关系模型计算海水施密特数为660时的海气界面气体传输速率k660。通过回归分析,得到由星载激光雷达数据反演k660的关系模型。将激光雷达数据反演结果与采用4种典型海面风速关系模型的计算结果进行比较,给出由星载激光雷达数据反演的4个月平均的海气界面气体传输速率全球分布图和纬度分布图。研究表明,CALIPSO星载激光雷达532nm单脉冲测量数据可用于反演海气界面气体传输速率。     

基于高光谱成像技术的番茄叶片灰霉病早期检测研究

提出了独立软模式法(SIMCA)的番茄叶片灰霉病特征波段图像的提取,并通过多元线性回归法(MLR)提取波段融合图像,通过最小距离法获取番茄灰霉病患病信息的技术路线。利用680～740 nm波段的方差图像和建模能力参数提取的特征波段,并作为输入变量进行MLR分析,在0.5准确率阈值下,准确率均大于99%,说明特征波段可以实现番茄叶片灰霉病的检测,并利用MLR回归系数提取波段融合图像,通过最小距离法获取番茄灰霉病患病信息,结果表明所提出的方法具有很好的预测能力,为番茄灰霉病的早期检测提供了一种新方法,且大大降低了高光谱图像的数据处理时间。     

RHIC能区的纵向流分布特征和核阻止特性的研究

首先利用相对论纵向非均匀集体流模型讨论RHIC能区的净质子分布特征,并分别与AGS,SPS的实验结果比较,发现,RHIC能区所产生的粒子系统具有很强的非均匀分布特征,表现为很强的核透明性,并分析了非均匀集体流模型与实验中的核阻止特性的紧密联系,接着分别研究了RHIC能区所产生质子、反质子和净质子的分布,这些研究可以帮助我们深入了解最新的RHIC能区的粒子分布和核阻止特征.     

Detecting and Analyzing Politically-Themed Stocks Using Text Mining Techniques and Transfer Entropy—Focus on the Republic of Korea’s Case

Politically-themed stocks mainly refer to stocks that benefit from the policies of politicians. This study gave the empirical analysis of the politically-themed stocks in the Republic of Korea and constructed politically-themed stock networks based on the Republic of Korea’s politically-themed stocks, derived mainly from politicians. To select politically-themed stocks, we calculated the daily politician sentiment index (PSI), which means politicians’ daily reputation using politicians’ search volume data and sentiment analysis results from politician-related text data. Additionally, we selected politically-themed stock candidates from politician-related search volume data. To measure causal relationships, we adopted entropy-based measures. We determined politically-themed stocks based on causal relationships from the rates of change of the PSI to their abnormal returns. To illustrate causal relationships between politically-themed stocks, we constructed politically-themed stock networks based on causal relationships using entropy-based approaches. Moreover, we experimented using politically-themed stocks in real-world situations from the schematized networks, focusing on politically-themed stock networks’ dynamic changes. We verified that the investment strategy using the PSI and politically-themed stocks that we selected could benchmark the main stock market indices such as the KOSPI and KOSDAQ around political events.     

Logistic混沌系统的熵特性研究

作为形式上相对较为简单的一维混沌函数,Logistic系统在很多领域有着重要的应用.本文主要分析了Logistic系统的熵稳定特性,对不同参数μ和系统初值形成的Logistic序列,进行了统计分类,得到了一系列的熵值,并详细分析了熵的分布情况.数值仿真结果表明,Logistic系统的熵由参数μ决定,而与系统初值基本无关,且当参数μ取值接近上界(μ=4)时,序列分布越趋于均匀,熵也接近理论极限值.     

基于固有光学量的高光谱数据反演城市河网水质

水体辐射传输模型是水体光谱特性分析的理论基础,水体固有光学量由水体组成决定,与水体表面光场无关。基于统计的半经验算法虽然能获取指定区域水质参数反演结果,但是缺乏物理意义;基于生物光学模型的分析算法,针对城市河网内陆Ⅱ类水体光学特性复杂、空间分布异质性强、水体细小、流动性大等特点,利用高光谱数据,研究基于固有光学量的城市河网水质参数反演模型,对内陆城市浑浊水体光谱特性研究具有重大意义。提出了适用于内陆城市河网水体的改进QAA算法,以获取水体固有光学量,改进包括后向散射估计模型调整和参考波段优化两个方面;计算参考波段总吸收系数、颗粒物后向散射系数等固有光学量,得到浮游植物吸收系数和剔除纯水吸收系数;对浮游植物吸收系数最优波段比值与叶绿素a浓度进行线性回归分析,构建叶绿素a水质浓度反演模型,对剔除纯水吸收系数最优波段比值与悬浮物浓度线性回归分析,构建悬浮物水质浓度反演模型。针对内陆河网Ⅱ类水体,以典型的河网城市嘉兴市为研究区域,获取了研究区域航空高光谱数据,以及水质采样化验数据和水面以上光谱数据等地面准同步测量数据;利用QAA算法和IIMIW算法对实测水面以上光谱进行固有光学量反演,对比分析两个算法并结合城市河网水体特点,提出改进QAA算法;利用改进的QAA算法实现了研究区域水体的固有光学量反演,基于反演的水体固有光学量建立了叶绿素a浓度和悬浮物浓度两项水色参数定量反演模型,反演模型决定系数R2分别为0.64和0.71;并用航空高光谱数据同步区域的4个地面样点实测数据,对反演结果进行验证分析。通过水质参数浓度反演值与实测值的对比,叶绿素a和悬浮物水质浓度反演的平均相对误差分别为9.2%和9.4%,反演得到的叶绿素a和悬浮物浓度分布图,也与城市河网的特点和实际情况相符,为城市河网水质监测提供方法和模型参考。     

基于DEM的战场目标侦察定位技术研究

针对现有侦察手段侦察定位精度低、速度慢的问题,运用数字摄影测量技术的相关理论与方法,提出了在DEM的基础上,以摄像机为"视点",通过透视模型的变换与相关算法计算获取所摄对像三维坐标的单摄像机侦察定位方法,给出了具体的实现步骤。目标定位实验表明,该方法具有定位精度高、实时性强的特点。     

Analysis of Electromagnetic Information Leakage Based on Cryptographic Integrated Circuits

Cryptographic algorithm is the most commonly used method of information security protection for many devices. The secret key of cryptographic algorithm is usually stored in these devices’ registers. In this paper, we propose an electromagnetic information leakage model to investigate the relationship between the electromagnetic leakage signal and the secret key. The registers are considered as electric dipole models to illustrate the source of the electromagnetic leakage. The equivalent circuit of the magnetic field probe is developed to bridge the output voltage and the electromagnetic leakage signal. Combining them, the electromagnetic information leakage model’s function relationship can be established. Besides, an electromagnetic leakage model based on multiple linear regression is proposed to recover the secret key and the model’s effectiveness is evaluated by guess entropy. Near field tests are conducted in an unshielded ordinary indoor environment to investigate the electromagnetic side-channel information leakage. The experiment result shows the correctness of the proposed electromagnetic leakage model and it can be used to recover the secret key of the cryptographic algorithm.     

基于Logistic模型的均值突变时间序列临界预警研究

对物理学中的非线性方程——Logistic方程解的稳定性进行分析, 发现当初值和参数取值一定时, 解具有从一种稳定状态突变到另一种稳定状态的特性. 突变的程度和速度与方程的控制参数有关, 可以用定义的突变强度指数来进行描述. 利用方程解的这一特性, 构造满足动力学结构突变的理想时间序列, 模拟气候系统中的均值突变, 考察物理量回复速率和回复力在系统趋近临界阈值时的临界行为, 研究其对系统突变的早期预警能力. 本文还讨论了当系统受到噪声信号干扰时, 回复速率和回复力仍然对系统突变有较好的预警. 最后, 对太平洋年代际振荡(PDO)指数序列进行检测, 检测结果表明早期预警信号出现在1973年前后, 而公认的PDO指数序列的突变发生在1976/1977年, 表明回复速率和回复力在一定程度上可以作为均值突变的早期预警信号.     

隧道围岩压力监测的非线性回归分析研究

隧道围岩压力的变化是导致公路隧道岩块错动、掉块、甚至塌方的重要因素。结合田心隧道工程,将一种可以把压力转变成光纤Bragg光栅波长移位的FBG土压力传感器应用于隧道围岩压力的监测;将40支土压力传感器安装在20个代表性断面中。采用非线性回归分析统计方法对隧道的量测数据进行分析,比较了监测数据的处理分析方法,选取最优的非线性回归分析模型。监测数据与回归拟合数据分析表明,非线性回归分析预测方法不仅可以反映隧道围岩变形和压力变化过程,还能根据其变化趋势进行结构异常判断。     

利用光谱数据快速检测土壤含水量的方法研究

应用美国ASD公司的FieldSpec HandHeld型可见/近红外光谱仪获得了52份不同含水量土壤的可见/近红外漫反射光谱数据,并通过实验测定了各土壤样本的含水量值,运用相关系数法寻找出了光谱对于土壤水分的敏感波段,然后利用单一敏感波段处的光谱数据建立了一元回归模型, 并检测了土壤含水量。实验结果表明, 该模型对土壤水分的检测效果比较好,模型的预测相关系数r为0.966 5,预测均方根误差RMSEP为0.012 1,为快速、准确检测土壤含水量提供了一条新的途径。     

AlON-TiN复相材料合成工艺参数的支持向量回归分析

根据在不同热压烧结工艺参数（包括TiN的含量、烧结温度和保温时间）下合成的AlON-TiN复相材料的抗弯强度实测数据集,应用基于粒子群算法寻优的支持向量回归（SVR）方法,建立了AlON-TiN复相材料在不同热压烧结工艺参数下抗弯强度的SVR预测模型,并与基于人工神经网络（ANN）模型的预测结果进行了比较.利用SVR预测模型并结合粒子群算法对AlON-TiN合成工艺参数进行了寻优和多因素分析.结果显示:对于相同的训练样本和检验样本,AlON-TiN复相材料抗弯强度的SVR模型比ANN模型具有更小的预测误差,表明SVR模型比ANN模型具有更强的预测能力.工艺参数寻优结果表明,当TiN质量分数为13.5%、烧结温度为1863.5 ℃和保温时间为5.8 h时, 可获得抗弯强度为555.452 MPa的AlON-TiN复相材料. 研究结果表明,该方法对于研发理想抗弯强度的AlON-TiN复相材料具有重要的理论指导意义和实用价值. 关键词： AlON-TiN 抗弯强度 支持向量回归 回归分析