基于多子空间直和特征融合的人脸识别算法

多个子空间直和能保证多个子空间数据融合时多个子空间得到的特征向量相互两两正交,融合数据采用该特征表示时冗余最小,更有利于分类识别。本文基于多子空间直和进行特征融合,提出了一种新的人脸识别算法。通过 2DPCA算法,首先分别计算所有训练样本归一化后正脸、左侧脸及右侧脸图像的协方差矩阵的各P个最大特征值对应的P个相互正交的特征向量,然后通过选取3个子空间的部分满足直 和条件的特征向量组成各自的特征空间(投影空间),再将样本正脸、左侧脸及右侧脸图像分别向各自特征空间投影得到3个特征矩阵,最后将此3个特征矩阵融合为该样本的特征矩阵用于最近邻分类器进行分类识别。最终通过本文3组实验数据的对比说明了该 算法能减少计算量并且提高了识别率。     

Optimization of the flame characteristics of H2–O2 coaxial injection applied to hydrogen-fueled argon cycle engines

The argon power cycle is one of the most promising technologies for high efficiency and low emission hydrogen-fueled internal combustion engines. The application of coaxial injection technology in the hydrogen-fueled argon engine can improve the mixing process and the combustion performance of the H₂/O₂ mixture. In this study, an innovative H₂–O₂ coaxial injection combustion system was designed to investigate the jet flame characteristics of oxygen coaxially wrapped by hydrogen in a controllable argon thermal atmosphere. The findings of this study could provide a new perspective for designing hydrogen-fueled argon engines in the future. The influences of co-flow temperature, jet injection pressure, and excess oxygen coefficient were all determined. Observations of the flame showed a bright blue flame with a reddish glow in the far-burner region. Experimental results show that the flame length, cross-sectional area, and area/perimeter ratio first decrease with increasing jet injection pressure and subsequently increase, reaching maximum values at 0.4–0.6 MPa. When increasing the co-flow temperature from 1023 K to 1223 K, the cross-sectional area of the flame increases significantly by 61.1% at an excess oxygen coefficient of 0.4. Furthermore, the liftoff flame height shrinks when the co-flow temperature and the excess oxygen coefficient increase, while it rises along with an increasing jet injection pressure.     

Decoupling in infinite dimensions

The decoupling problem is to find a feedback control law for a linear system which stabilizes the system in such a way that external inputs each completely control one output, but have no influence on the rest. An infinite-dimensional version of this problem is solved assuming finitely many outputs and inputs.     

泛函分析对线性代数的点滴应用

本文利用泛函分析方法,论述了线性方程组理论与二次型,为工科线性代数教材的改革,提供了一个方案。     

镁合金消失模铸造的优势及关键

对常见镁合金铸造工艺作了分析和总结，对镁合金消失模工艺的优缺点作了客观分析；提出了可控气氛、可控压力镁合金消失模铸造新工艺；认为该工艺是一种非常适合镁合金液态成形的新的精密铸造方法，具有设备投资小、铸件成本低、内在质量好、精度高、生产率高的优势，同时可以较好地解决镁合金液态成形过程中易氧化燃烧的问题。     

Necessary and sufficient conditions for existence of J-spectral factorization for para-Hermitian rational matrix functions

For a para-Hermitian rational matrix function G(λ)=J+C(λI_p−A)⁻¹B, where J=J∗ is invertible, and which has no poles and zeros on the imaginary line, we give necessary and sufficient conditions in terms of A,B,C and J for the existence of a J-spectral factorization, as well as an algorithm to obtain the J-spectral factor in case it exists.     

On the geometry of symplectic pencils arising from discrete-time matrix equations

In this paper general symplectic matrix pencils are considered disregarding the particular matrix equations from which they arise. A parameterization of the Lagrangian deflating subspaces is given with the only assumption of regularity of the matrix pencil.     

A probabilistic‐based approach for direction‐of‐arrival estimation and localization of multiple sources

This article contributes to science at two points. The first contribution is at a point of introducing a novel direction‐of‐arrival (DOA) estimation method which based on subspaces methods called Probabilistic Estimation of Several Signals (PRESS). The PRESS method provides higher resolution and DOA accuracy than current models. Second contribution of the article is at a point of localizing the unknown signal source. The process of localization achieved by using DOA information for the first time. The importance of localization exists in a large area of engineering applications. The aim is to determine the location of multiple sources by using PRESS with minimum effort of computation. We used the maximum probabilistic process in this study. Initially, all the signals are collected by the array of sensors and accurately identified using the proposed algorithm. The receiver at the best in test estimates the source location using only the knowledge of the geographical latitude and longitude values of the array of sensors. Several test points with an accurately calculated angle of arrival enable us to draw linear lines towards the transmitter. The transmitter location can be accurately identified with the line of interceptions. Simulation and numerical results show the outstanding performance of both the DOA estimation method and transmitter localization approach compared with many classical and new DOA estimation methods. The PRESS localization method first tested at 19°, 26°, and 35° with an signal‐to‐noise ratio (SNR) value of ‐5 dB. The PRESS method produced results with an extremely low bias of 0 and 0.00080°. The simulation tests are repeated and produced results with zero bias, which give the exact location of the unknown source.     

具有可控与不可控因素系统的可靠性维持方法

为了研究系统或元件可靠性维持方法,提出一种基于SFT的可靠性维持方法。在SFT框架下提出了可控与不可控因素的概念。目前SFT中的不可控因素指时间,其余为可控因素。给出了分析并制定系统或元件可靠性维持方法的步骤。分析表明在SFT内必须设定故障概率才能实施该方法。列举了一例进行分析,考虑的不可控因素为时间t,可控因素为温度c。分别将故障概率设置为10%、20%、30%、40%,50%,求出了元件更换周期,及其温度控制曲线和函数。与已有文献相比所得元件更换周期更为经济,方法更精确且可操作增强性。