Research on Factors of Linear Algebra Learning Effect

Linear algebra has a very important application in physics and technical disciplines. This article conducted a questionnaire survey on the factors that affect the effect of linear algebra learning;the questionnaire contains several aspects of learning attitude, learning interest, learning methods, teaching methods, etc.;based on recycling data, cross chi-square test and multiple logistic regression analysis are used to obtain the factors that affect the effect of linear algebra learning. The research results show that: learning methods, learning attitudes, teaching methods and elementary algebra basics are the main factors that affect the learning effect of linear algebra;among them, there are positive correlations between teaching methods, learning methods, learning attitudes and learning effects;teaching methods, learning methods 3. The three principal components of learning attitude are positively correlated. Based on the research and analysis, the following conclusions are drawn: finding a suitable learning method for the college students and maintaining a positive learning attitude are effective means to improve the linear algebra learning effect of the college students;in teaching, it is recommended to advance with the times, the teaching content and teaching methods innovate to stimulate students’ interest in learning, thus improving the learning effect of college students’ linear algebra courses.

Factorization of Operators in Krein Spaces and Linear-Fractional Relations of Operator Balls

We consider plus-operators in Krein spaces and generated operator linear fractional relations of the following form: . We study some special type of factorization for plus-operators T, among them the following one: T = BU, where B is a lower triangular plus-operator, U is a J-unitary operator. We apply the above factorization to the study of basical properties of relations (1), in particular, convexity and compactness of their images with respect to the weak operator topology. Obtained results we apply to the known Koenigs embedding problem, the Krein-Phillips problem of existing of invariant semidefinite subspaces for some families of plus-operators and to some other fields.

Assessing the Effect of Climate Factors on Dengue Incidence via a Generalized Linear Model

Changes in climate factors such as temperature, rainfall, humidity, and wind speed are natural processes that could significantly impact the incidence of infectious diseases. Dengue is a widespread disease that has often been documented when it comes to the impact of climate change. It has become a significant concern, especially for the Malaysian health authorities, due to its rapid spread and serious effects, leading to loss of life. Several statistical models were performed to identify climatic factors associated with infectious diseases. However, because of the complex and nonlinear interactions between climate variables and disease components, modelling their relationships have become the main challenge in climate-health studies. Hence, this study proposed a Generalized Linear Model (GLM) via Poisson and Negative Binomial to examine the effects of the climate factors on dengue incidence by considering the collinearity between variables. This study focuses on the dengue hot spots in Malaysia for the year 2014. Since there exists collinearity between climate factors, the analysis was done separately using three different models. The study revealed that rainfall, temperature, humidity, and wind speed were statistically significant with dengue incidence, and most of them shown a negative effect. Of all variables, wind speed has the most significant impact on dengue incidence. Having this kind of relationships, policymakers should formulate better plans such that precautionary steps can be taken to reduce the spread of dengue diseases.

SPSS中UNIANOVA与Linear的应用研究

SPSS软件在我国的社会科学、自然科学的各个领域发挥着巨大的作用。方差分析与线性回归分析是SPSS软件中的两种分析方法,在解决实际问题时应用最多。但两者有很多相似之处,在进行实际问题分析时,对于选择何种分析方式以及分析结果的解释理解经常会给使用者造成困惑。通过对两个过程的比较分析总结了两者的相同与相异之处,尤其指出两者之间的本质差别,并列举实例来说明实际应用时如何根据实际情况选择正确合适的方法。

Evaluation of correlation between PM2.5 and radon-progeny equilibrium factor in radon chamber

The dosage of environmental radon progeny is typically estimated according to the environmental radon exposure and the recommended radon-progeny equilibrium factor, F. To investigate the relationship between PM2.5 and the radon-progeny equilibrium factor, cigarettes are used to simulate the haze–fog in a multi-functional radon chamber to achieve a stable radon concentration environment. A radon detector and a portable laser aerosol spectrometer are used to obtain the values for C_(mean) PM2.5,C_(Rn), and C_p. The results show that the mean values of F conform with the typical value recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation and are within the reasonable range of0.1–0.9. In this study, a positive correlation is observed between the F values and PM2.5 concentrations.

Design of a Transverse-flux Permanent-magnet Linear Generator and Controller for Use with a Free-piston Stirling Engine

Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is developed.The impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor.The relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a goal.At last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is achieved.The power factor is improved and the process complexity is decreased.This research provides the instruction to design high-power factor permanent-magnet linear generator.

Electromagnetic Oscillations in a Spherical Conducting Cavity with Dielectric Layers. Application to Linear Accelerators

We present an analysis of electromagnetic oscillations in a spherical conducting cavity filled concentrically with either dielectric or vacuum layers. The fields are given analytically, and the resonant frequency is determined numerically. An important special case of a spherical conducting cavity with a smaller dielectric sphere at its center is treated in more detail. By numerically integrating the equations of motion we demonstrate that the transverse electric oscillations in such cavity can be used to accelerate strongly relativistic electrons. The electron’s trajectory is assumed to be nearly tangential to the dielectric sphere. We demonstrate that the interaction of such electrons with the oscillating magnetic field deflects their trajectory from a straight line only slightly. The Q factor of such a resonator only depends on losses in the dielectric. For existing ultra low loss dielectrics, Q can be three orders of magnitude better than obtained in existing cylindrical cavities.

A UNIVERSAL ANALYTIC POTENTIAL-ENERGY FUNCTION BASED ON A PHASE FACTOR

Using a field equation with a phase factor, a universal analytic potential-energy function applied to the interactions between diatoms or molecules is derived, and five kinds of potential curves of common shapes are obtained adjusting the phase factors. The linear thermal expansion coefficients and Young's moduli of eleven kinds of face-centered cubic (fcc) metals - Al, Cu, Ag, etc. are calculated using the potential-energy function; the computational results are quite consistent with experimental values. Moreover, an analytic relation between the linear thermal expansion coefficients and Young's moduli of fcc metals is given using the potential-energy function. Finally, the force constants of fifty-five kinds of diatomic moleculars with low excitation state are computed using this theory, and they are quite consistent with RKR (Rydberg-Klein-Rees) experimental values.

Linear Quadratic Integral Control for the Active Suspension of Vehicle

The quarter model of an active suspension is established in the form of controllable autoregressive moving average （CARMA） model. An accelerometer can be mounted on the wheel hub for measuring road disturbance; this signal is used to identify the CARMA model parameters by recursive forgetting factors least square method. The linear quadratic integral （LQI） control method for the active suspension is presented. The LQI control algorithm is fit for vehicle suspension control, for the control performance index can comprise multi controlled variables. The simulation results show that the vertical acceleration and suspension travel both are decreased with the LQI control in the low frequency band, and the suspension travel is increased with the LQI control in the middle or high frequency band. The suspension travel is very small in the middle or high frequency band, the suspension bottoming stop will not happen, so the vehicle ride quality can be improved apparently by the LQI control.

基于STIRPAT模型的京津冀地区碳排放影响因素分析

采用STIRPAT模型,分析了影响京津冀地区碳排放的主要因素.首先,利用IPCC方法对京津冀地区碳排放量进行测算.其次,在现有研究的基础上,筛选出与碳排放相关的影响因素,运用主成分分析法、岭回归法和线性回归法对京津冀地区碳排放量影响因素进行了实证分析.最后,在京津冀不同区域分别构建了改进的STIRPAT模型,探究关键因素的影响程度,并对碳排放影响因素进行了深入分析.实证研究表明,2000—2019年京津冀地区碳排放结构与变化趋势明显不同.同时,各区域关键影响因素各不相同,同一因素在不同区域产生的效果也有所不同.

颅内动脉直径与脑小血管病患者认知功能的关系

目的探讨颅内动脉直径与脑小血管病(CSVD)患者认知功能之间可能存在的关系,以求为血管性认知功能障碍(VCI)患者的早期识别、诊断及预后提供新的思路。方法回顾性分析2022-01—2023-12在郑州大学第二附属医院及新郑市公立人民医院住院的151例CSVD患者,采用蒙特利尔认知量表(MoCA)评估受试者的认知功能情况,分为认知功能正常组88例和认知功能障碍组63例,使用3D-Slicer软件对患者原始MRI图像进行处理,得出颅内动脉重塑(BAR)评分。根据BAR评分将患者分为颅内大动脉直径缩窄组(58例)、颅内大动脉直径平均组(37例)、颅内大动脉直径扩张组(56例)。应用Logistic回归分析颅内动脉直径与认知功能障碍的关系,Pearson相关性分析颅内动脉直径与MoCA总分及MoCA各子项得分的关系。结果Logistic回归分析提示颅内动脉直径扩张(OR=1.214,95%CI:1.127~1.307,P<0.01)是认知功能障碍的危险因素。颅内动脉直径扩张与MoCA总分(r=-0.306,P<0.001)、视空间与执行功能(r=-0.237,P=0.003)、语言(r=-0.238,P=0.003)、抽象(r=-0.160,P=0.049)、延迟回忆(r=-0.180,P=0.027)、定向(r=-0.163,P=0.046)呈负相关。结论颅内动脉直径扩张是CSVD患者认知功能障碍的危险因素,颅内动脉直径扩张与MoCA校正后总分、视空间与执行功能、语言、抽象、延迟回忆、定向力呈负相关。

基于城市体检的中心城市治理满意度测度及影响因素研究

基于2020年城市体检问卷调查数据,利用多层线性模型测度我国36个中心城市的城市治理综合水平及其差异,探索影响城市治理的关键因素。结果表明:从空间特征来看,治理评价高水平城市多分布于长江沿线和东部沿海地区,偏低水平多分布在西北地区和东北地区;从城市间差异来看,城市治理存在“短板效应”,城市间生态环境治理和道路环境提升存在显著差异;从关键影响因素来看,居民对城市治理的综合感知受到城市建成环境、城市社会经济条件和个体属性特征共同作用。在城市建成环境变量中,高建成区绿化覆盖率、低PM_(2.5)浓度、高公交站点和商场可达性促进居民对城市治理满意度的提升。在城市社会经济条件变量中,大经济规模、高工资水平增强居民对城市治理的满意度。在个体属性变量中,高龄、高学历及城市“新市民”对城市治理的效果敏感度更高。

基于LSTM的多因素石灰窑煅烧带温度预测研究

针对石灰窑煅烧过程易出现燃烧不平衡的问题以及石灰窑煅烧系统的滞后性,提出了大数据分析+神经网络的解决方案。利用大数据分析对石灰窑多源历史数据进行数据融合插补,采用多元线性回归方程分析空间因素对温度的影响,通过时间滑窗提取特征,在此基础上利用长短期记忆神经网络(LSTM)算法构建多因素模型,并采用自适应运动估计算法进行优化。实验结果表明:较单因素LSTM模型,多因素LSTM模型有效提高了石灰窑温度预测精度,现场可根据预测值提前调整工艺参数,实现了石灰窑局部温度预测。

变长分段直线感应电机数学建模

变长分段直线感应电机参数具有不连续、快速时变及强耦合特性,这给电磁暂态建模带来挑战。该文引入3种时变因子推导出具有参数时变特性的变长分段直线感应电机数学表达式。通过分析变长分段直线感应电机定子与动子的电磁耦合特性及时变因子与状态变量之间的耦合关系,建立定子、动子及时变因子相互解耦的数学模型。仿真结果表明,该数学模型计算的电压、电流和速度与有限元计算结果差别小于6%,验证了数学模型的准确性。硬件在环实验结果表明,在高速工况下数学模型可以准确模拟系统的电磁暂态特性,验证了数学模型的解耦能力及数值运算稳定性。

基于气象因子的谷子品质预测模型构建及应用

基于2019—2021年山西省10个谷子主产区主要品质指标(直链淀粉、粗蛋白、粗脂肪、维生素B1、胶稠度和碱消值)和同期气象资料,利用线性回归统计学方法,分析不同生长阶段多种气象因子对谷子品质的影响,并构建谷子品质的预测模型,旨在为谷子气候品质认证提供科学依据。结果表明,影响谷子品质指标的气象因子不是单一的,且不同生长阶段的气象因子对品质的影响也不尽相同;生殖生长阶段尤其是抽穗—乳熟阶段的气象因子决定了谷子的品质,影响谷子品质的主要气象因子为平均气温、平均最高气温、≥10℃活动积温、累计降水量、累计日照时数和气温日较差。其中,限制谷子品质提升的主要气象因子是抽穗—乳熟阶段的气温日较差和累计降水量。利用构建的谷子品质指标预测模型,对晋北、晋中、晋南和晋东南进行谷子品质拟合检验,结果显示,6个谷子品质指标预测模型拟合系数为0.63~0.89,尤其对直链淀粉、粗蛋白和粗脂肪含量的预测效果较好,拟合系数均达到0.8以上。

Intrinsic noise analysis and stochastic simulation on transforming growth factor beta signal pathway

A typical biological cell lives in a small volmne at room temperature; the noise effect on the cell signal transduction pathway may play an important role in its dynamics. Here, using the transforming growth factor-β signal transduction pathway as an example, we report our stochastic simulations of the dynamics of the pathway and introduce a linear noise approximation method to calculate the transient intrinsic noise of pathway components. We compare the numerical solutions of the linear noise approximation with the statistic results of chemical Langevin equations, and find that they are quantitatively in agreement with the other. When transforming growth factor-β dose decreases to a low level, the time evolution of noise fluctuation of nuclear Smad2-Smad4 complex indicates the abnormal enhancement in the transient signal activation process.

疫情后深圳市生活垃圾产生量的预测及变化分析

疫情后针对生活垃圾产生量的变化,开展预测并对结果进行分析,是地方政府科学制定相关规划、合理布局环卫设施建设的重要依据。因此,立足深圳市疫情前后数据,结合灰色关联度模型、多元线性回归等方法,分析2022—2035年生活垃圾产生量预测值的变化。结果表明,生活垃圾产生量保持逐年增长趋势,规划期末水平年(2035年)的具体数值有一定程度调整。预测到2035年的生活垃圾产生量为45 547 t/d,其中再生资源回收量为14 576 t/d,生活垃圾处理处置量为30 971 t/d。建议各项环卫设施建设可灵活调整设施规模及建设周期,提升城市垃圾处理效能。

Approximate analytical solution of non-linear reaction diffusion equation in fluidized bed biofilm reactor

A mathematical model for the fluidized bed biofilm reactor (FBBR) is discussed. An approximate analytical solution of concentration of phenol is obtained using modified Adomian decomposition method (MADM). The main objective is to propose an analytical method of solution, which do not require small parameters and avoid linearization and physically unrealistic assumptions. Theoretical results obtained can be used to predict the biofilm density of a single bioparticle. Satisfactory agreement is obtained in the comparison of approximate analytical solution and numerical simulation.

考虑用户负荷率因素的电力市场偏差电量定价方法

针对偏差电量定价中尚未考虑用户的负荷率变化,导致电力交易各方的经济利益不均衡问题,提出考虑用户负荷率因素的电力市场偏差电量定价方法。以售电量时间序列为基准,完成基于多元线性回归的电力市场售电量预测。在此基础上,建立基于月用电量偏差率的惩罚机制,考虑负荷率和偏差率的变化确定对应偏差电量的电价。通过某区域电力市场交易数据试验,负荷率的波动直接影响购电公司收益,提出的偏差电量定价方法能够降低偏差考核电费对整体收益的影响,规范电量市场交易行为,在一定程度上均衡用户和售电企业各方的利益。

股骨颈骨折患者术后延迟愈合与微循环因子相关性研究

目的:研究股骨颈骨折术后延迟愈合与微循环因子的相关性,以期为促进骨折患者术后早期愈合提供可靠方向。方法:选取2019—2022年在复旦大学附属闵行医院接受内固定手术治疗的股骨颈骨折患者,根据患者术后愈合情况,将其分为正常愈合组(n=87)和延迟愈合组(n=33)。术后6个月对所有患者微循环指标进行检测,对比不同愈合情况患者的微循环因子水平,并分析微循环因子对股骨颈骨折术后延迟愈合的影响。结果:正常愈合组血浆黏度、全血低切黏度、红细胞聚集指数及甲襞微循环形态、流态及襻周积分均低于延迟愈合组,差异有统计学意义(t值分别为9.301、6.368、12.805、11.616、18.788和17.980,P值均<0.05)。正常愈合组血清内皮素(ET)和血清C反应蛋白(CRP)水平低于延迟愈合组,差异有统计学意义(t值分别为6.784和6.410,P值均<0.05)。线性回归分析结果显示,全血低切黏度、血浆黏度、红细胞聚集指数、甲襞微循环形态、流态、襻周积分及ET、CRP是股骨颈骨折患者术后延迟愈合的影响因素。结论:微循环状态及微循环指标ET、CRP水平均在股骨颈骨折术后延迟愈合患者中呈高表达,是患者术后延迟愈合的影响因素。