长治水泥厂区域地震地质环境评价

长治水泥厂位于山西隆起区南部长治盆地, 长治盆地属中强潜在震原区。场地附近晋获断裂现代活动相对较弱, 晚更新后断裂基本停止活动, 对水泥厂场地无直接影响。     

Dynamic output feedback fault tolerant controller design for discrete-time switched systems with actuator fault

This paper investigates the problem of dynamic output feedback fault tolerant controller design for discrete-time switched systems with actuator fault. By using reduced-order observer method and switched Lyapunov function technique, a fault estimation algorithm is achieved for the discrete-time switched system with actuator fault. Then based on the obtained online fault estimation information, a switched dynamic output feedback fault tolerant controller is employed to compensate for the effect of faults by stabilizing the closed-loop systems. Finally, an example is proposed to illustrate the obtained results.     

运载火箭多表冗余捷联惯组的故障诊断与决策

为了提高运载火箭惯导系统的可靠性,介绍了一种多表冗余捷联惯性测量组合的故障诊断和冗余信息重构技术,对陀螺仪和加速度计信息采取三取二的冗余、诊断的管理策略,将故障定位到具体惯组的某个敏感轴,对故障惯组隔离后进行信息重构,实现故障情况下的导航信息的正常输出,增强了运载火箭对惯组故障的适应能力。     

基于拉普拉斯分值和超球支持向量机的轴承故障诊断方法设计

针对轴承振动信号中的故障信息往往很微弱,同时振动样本数据分布不平衡即故障样本占总样本数的比例低,从而导致故障诊断模型训练不精确而影响诊断精度的问题,提出了一种基于拉普拉斯分值和超球大间隔支持向量机的故障诊断方法。首先,采用有标签的训练样本数据和拉普拉斯分值法提取原始振动信号中的微弱故障信息,并降低其数据维数,从而得到用于故障诊断的特征向量,然后设计了一种改进的超球大间隔支持向量机的故障诊断模型,通过最小化超球体积和最大化超球边界和故障样本之间的间隔来实现故障诊断,以解决样本的不均衡问题,最终通过将测试样本数据代入决策方程并通过投票机制确定其故障类别。在Matlab环境下对轴承故障诊断进行实验,实验结果证明了文中方法能有效解决样本的不均衡情况下的故障诊断,且相对其它方法,具有诊断精度高和收敛速度快的优点。     

Structural analysis of electrical circuits including magnetoquasistatic devices

Modeling electric circuits that contain magnetoquasistatic (MQS) devices leads to a coupled system of differential-algebraic equations (DAEs). In our case, the MQS device is described by the eddy current problem being already discretized in space (via edge-elements). This yields a DAE with a properly stated leading term, which has to be solved in the time domain. We are interested in structural properties of this system, which are important for numerical integration. Applying a standard projection technique, we are able to deduce topological conditions such that the tractability index of the coupled problem does not exceed two. Although index-2, we can conclude that the numerical difficulties for this problem are not severe due to a linear dependency on index-2 variables.     

Formulation of the LED's radiant power⿿current characteristic at pulsed high currents

In many investigations on LEDs, the radiant power?current characteristic of LED has been drawing for high currents without giving any mathematical equation between them. The radiant power?current variation of LED can be expressed with a formula. In this study the thermal effect on radiant power of LED at pulsed high currents has been formulated and a mathematical equation has been derived between current amplitude and radiant power of LED. This equation has been examined by drawing theoretical and experimental variations on the same graph. In addition, the effect of instantaneous resistance?current variation of LED on its radiant power?current characteristic has been shown.     

Currents on Grassmann algebras

We define currents on a Grassmann algebra Gr(N) with N generators as distributions on its exterior algebra (using the symmetric wedge product). We interpret the currents in terms of ₂-graded Hochschild cohomology and closed currents in terms of cyclic cocycles (they are particular multilinear forms on Gr(N). An explicit construction of the vector space of closed currents of degree p on Gr(N) is given by using Berezin integration.     

Wind‐driven currents in a sea with a variable eddy viscosity calculated via a Sinc–Galerkin technique

The Sinc–Galerkin method is presented as a new and potentially useful extension of the spectral method in numerical oceanography. To describe and illustrate the technique, a Sinc–Galerkin procedure is used to infer the sensitivity of wind‐driven sub‐surface currents in coastal regions and semi‐enclosed seas when the vertical eddy viscosity coefficient is represented as a continuously differentiable function of depth. Problems with exact solutions are used to explore the accuracy and exponential convergence of expansions using composite translated sinc functions as a basis set. To illustrate the essential idea, we describe applications of the Sinc–Galerkin technique to modifications of the Ekman wind‐drift current problem. Copyright © 2000 John Wiley & Sons, Ltd.     

Influence of Majorana Bound States in Quantum Rings

A quantum ring coupled to a 1D topological superconductor hosting Majorana bound states (MBSs) is investigated. The MBSs effects over the spectrum and persistent current along the quantum ring are studied. The spectra of the system are obtained by an exact numerical diagonalization of the Bogoliubov-de Gennes Hamiltonian in the Majorana representation. In addition, Green's function formalism is implemented for analytical calculations and obtained a switching condition in the MBSs fermionic parity. Three different patterns that could be obtained for the spatial separation of the MBSs, named: bowtie, diamond, and asymmetric, are reported here, which are present only in odd parity in the quantum ring, while only a single pattern (bowtie) is obtained for even parity. Those patterns are subject strictly to the switching condition for the MBSs. Besides, quantum ring with the presence of a Majorana zero mode presents gapped/gapless spectra in odd/even parity showing in the even case a subtle signature in the persistent current.     

A fluctuation theorem for Floquet quantum master equations

We present a fluctuation theorem for Floquet quantum master equations. This is a detailed version of the famous Gallavotti–Cohen theorem. In contrast to the latter theorem, which involves the probability distribution of the total heat current, the former involves the joint probability distribution of positive and negative heat currents and can be used to derive the latter. A quantum two-level system driven by a periodic external field is used to verify this result.