基于无微分扰动观测器的水泥厂风机能效辨识系统

预热器引风机、磨粉机引风机和袋房引风机是水泥厂用电大户。考虑到近年来水泥市场竞争越来越激烈,评估这些风机及其通风系统的能效,优化运行效率以节省消耗的电力是非常有必要的。这些节能优化也可以大大减少排放和整个生产过程的碳足迹。现有的能效评估多采用预埋传感器的嵌入方式实现的,成本高,周期长。设计了一种基于在线参数的水泥厂风机系统非嵌入式无微分扰动观测器辨识系统能效,对永磁同步电机驱动离心风机系统进行估计。建立了系统设计的模型,搭建了软硬件,进行了系统测试,结果表明了能效辨识系统的有效性。

Nelder-Mead单纯形算法改进及在气象上的应用

Nelder-Mead Simplex(NMS)算法是一种查找多元函数局地最小值的无微分算法,在现代科学计算中得到广泛应用,该文提出了一种对NMS算法的改进方法。改进后,大大简化了其计算过程,提高了该算法的收敛速度。利用改进后的算法对陆面过程参数进行了拟合计算,结果表明:改进的NMS算法对非线性公式具有非常高的拟合精度,可将其应用于气象学上非线性问题计算或非线性方程组求解。

Conserved quantities from Lie symmetries for nonholonomic systems

This paper presents a new method to seek the conserved quantity from a Lie symmetry without using either Lagrangians or Hamiltonians for nonholonomic systems. The differential equations of motion of the systems are established. The definition of the Lie symmetrical transformations of the systems is given, which only depends upon the infinitesimal transformations of groups for the generalized coordinates. The conserved quantity is directly constructed in terms of the Lie symmetry of the systems. The condition under which the Lie symmetry can lead to the conserved quantity and the form of the conserved quantity are obtained. Finally, an example is given to illustrate the application of the result.

Operator Methods in High Order Partial Differential Equation

For linear partial differential equation 〔 2t 2-a 2P( x)〕 m u=f(x,t), where m1,X∈R n,t∈R 1, the author gives the analytic solution of the initial value problem using the operators sh(tP( x) 1/2 )P( x) 1/2 . By representing the operators with integrals, explicit solutions are obtained with an integral form of a given function.

Existence of Positive Solutions for Boundary Value Problems on the Semi-infinite Interval

In this paper, the authors study the existence of positive solution of the following BVP {1/p（t）（P（t）x′）′＋f（t,x（t）,p（t）x′（t））=0,o〈t〈＋∞ αx（0）-βlimt→0p（t）x′（t）=0,γ limt→＋∞x（t）＋δlimt→＋∞p（t）x′（t）=0 on the semi-infinite interval. By considering characterization of the nonlinearity, they obtain some new existence results.

Non-Cooperative Differential Game Based Load Balancing Algorithm in Radio-Over-Fibre System

Load balancing plays a critical role in a cellular network. As one kind of cellular network, Radio-over-Fibre （RoF） system can provide ubiquitous high data-rate transmissions, which has attracted many attentions, but it also suffer load unbalancing problem. In order to improve the system performance, in this paper, we propose a novel loading balance scheme in RoF system based on differential game theory. The scheme formulates the load allocated to each RAP （Radio Access Point） as a Nasb Equilibrium, using non-cooperative differential game to obtain the optical load allocation of each RAP. The simulations performed show that the non-cooperative differential game algorithm is applicable and the optimal load solution can be achieved.

The H-stability of the Solution for Infinite Delay Functional Differential Equation

H stability is a new and important concept. In this paper,we discuss the equationx(t)=-a(t)x(t)+∫ t -∞ k(t,s-t,x(s)) d sand we gain a new decision theorem. Using this decision theorem,we obtained a very extensive result of the H uniformly asymptotical stability of this equation. That is,eliminating the restriction that a(t) is bounded.

Treatment of Aplastic Anemia by the Kidney-Tonifying and Mediating Method

In this series of 65 cases of aplastic anemia, 26 cases were treated by the kidney-tonifying and mediating method, 19 cases by western drugs, and the remaining 20 cases only by tonifying the kidney as controls. The results showed that the kidney-tonifying and mediating method was significantly superior in the total effective rate to the method of western drugs and that of tonifying the kidney alone (P

A NOVEL LINEAR DIFFERENTIAL SPACE-TIME MODULATION

Based on the Complex Orthogonal Linear Dispersion (COLD) code,a novel linear Differ- ential Space-Time Modulation (DSTM) design is proposed in this paper.Compared with the existing nonlinear DSTM schemes based on group codes,the proposed linear DSTM scheme is easier to design, enjoys full diversity and allows for a simplified differential receiver,which can detect the transmitted symbols separately.Furthermore,compared with the existing linear DSTM based on orthogonal design, our new construction can be applied to any number of transmit antennas.Similar to other algorithms, the proposed scheme also can be demodulated with or without channel estimates at the receiver,but the performance degrades approximately by 3dB when estimates are not available.

Strong/weak limits and strong/weak differentials of multi-variable indeterminate forms. I: Deduction and geometric illustration

Strong and weak limits as well as strong and weak differentials of multi-variable indeterminate forms are discussed based on the thorough exploration of differentiation to solve the strong and weak limits and differentials of unitary indeterminate forms. The fruit of this work is going to be reported in three parts. The first part presents the standard analysis on this subject which supplements, systematizes and advances L. Hospital抯 principles on differential calculus by applying special ,general, and limit guaranteeing theories together with K(t) and XhK0 theories. The combination of theoretical analysis and geometric signification makes the derivation intuitional, visual and easy to perceive.

Infinitely Many Conservation Laws of a Differential-difference Equation and Backlund Transformation

In this paper, with the help of the Lax representation, we show the existence of infinitely many conservation laws for a differential-difference equation,which is one of the Ladic-Ablowitz hierarchy, and the conservation density and the associated flux are given formularlly. We also demonstrate the relation between a continuous partial differential equation and the differential-difference equation, and give Backlund transformation for the former.

Periodic Solutions of Singular Neutral Differential Systems with Infinite Delay

In this paper,we discuss the periodic solutions of the nonlinear singular neutral differential systems with infinite delay.By using matrix measure and Krasnoselskii＇s fixed point theorem,we obtained the suffcient conditions of the existence of periodic solutions.

The Design of Small Micro-UAV Formation of ＂Sub-mother＂ type

This paper aims to provide a design about a kind of low-cost ＂sub-mother＂ UAV small formation by using the low-cost micro-UAV as the platform. Combined with the current international situation in the UAV formation research, the modeling is based on the distributed control method and the behavior-based strategy. In this paper, some research to a few key issues has been carried out.

Steady-State Performance Analysis of Brushless DC Propulsion Motor

The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the high-power shipping during the design stage, the steady-state analysis is as important as the dynamic analysis generally. A mathematical model of the brushless DC propulsion motor is established according to the state-space method for the dynamic and steady-state performance analysis. The state-space mathematical model is a set of linear differential equations, so the steady-state currents of the armature windings can be gained directly by the symmetrical boundary conditions and the eigenvalues of the system matrix. The steady-state simulation results are compared with the dynamic ones to validate the correctness of this eigenvector method.

Existence of Solutions for Forward-Backward Stochastic Differential Equations with Jumps and Non-Lipschitzian Coefficients

This paper studies for ward-back ward differential equations with Poisson jumps and with stopping time as termination. Under some weak monotonicity conditions and for non-Lipschitzian coefficients, the existence and uniqueness of solutions are proved via a purely probabilistic approach, while a priori estimate is given. Here, we allow the forward equation to be degenerate.

A seamless operation mode transition control strategy for a microgrid based on master-slave control

This paper proposes a control strategy that can realize seamless microgrid operation mode transition between grid-connected operation and stand-alone operation.The scenario of a microgrid based on master-slave control is considered,where the master distributed generation(DG) unit operates in different control schemes in different microgrid operation modes,while other slave DG units operate with power/current control all the time.The proposed control strategy focuses on the master DG unit,and contains the control state/reference compensation algorithm and separation switch control logic.The proposed method can effectively reduce the impact on the critical loads and DG units caused by microgrid operation mode transitions.

Neuro-heuristic computational intelligence for solving nonlinear pantograph systems

We present a neuro-heuristic computing platform for finding the solution for initial value problems （IVPs） of non- linear pantograph systems based on functional differential equations （P-FDEs） of different orders. In this scheme, the strengths of feed-forward artificial neural networks （ANNs）, the evolutionary computing technique mainly based on genetic algorithms （GAs）, and the interior-point technique （IPT） are exploited. Two types of mathematical models of the systems are constructed with the help of ANNs by defining an unsupervised error with and without exactly satisfying the initial conditions. The design parameters of ANN models are optimized with a hybrid approach GA-IPT, where GA is used as a tool for effective global search, and IPT is incorporated for rapid local convergence. The proposed scheme is tested on three different types oflVPs of P-FDE with orders 1-3 The correctness of the scheme is established by comparison with the existing exact solutions. The accuracy and convergence ofthc proposed scheme are further validated through a large number of numerical experiments by taking different numbers of neurons in ANN models.

Analysis and control of distributed parameter systems for applications:Research progress and prospects

Most systems arising in engineering fields are spatiotemporal processes in nature so that their behavior must depend on time as well as spatial position.These spatiotemporal processes are in general modeled by partial differential equations.Substantial literature on the research of distributed parameter systems(DPSs)has been reported over the past decades.Amount of results on analysis and control of DPSs have been developed in these research articles,which include not only extensions of finite-dimensional techniques to infinite-dimensional systems but also innovative infinite-dimensional analysis and control design approaches.Hence,a comprehensive survey of all the developments of DPSs is perhaps a very difficult task.This paper,however,attempts to present a brief yet reasonable overview of research on the analysis and control of distributed parameter systems for applications.To help readers,some simple mathematical descriptions and necessary figures are involved in this article.Finally,some open areas of research and possible directions have also been outlined.

Effects of the Aspect Ratio on the Optimal Tilting Angle for Maximum Convection Heat Transfer across Air-filled Rectangular Enclosures Differentially Heated at Sides

Natural convection in air-filled rectangular cavities inclined with respect to gravity, so that the heated wall is facing upwards, is studied numerically under the assumption of two-dimensional laminar flow. A computational code based on the SIMPLE-C algorithm is used for the solution of the system of the mass, momentum and energy transfer governing equations. Simulations are performed for height-to-width aspect ratios of the enclosure from 0.25 to 8, Rayleigh numbers based on the length of the heated and cooled walls from 10~2 to 10~7, and tilting angles of the enclosure from 0° to 75°. The existence of an optimal tilting angle is confirmed for any investigated configuration, at a location that increases as the Rayleigh number is decreased, and the height-to-width aspect ratio of the cavity are increased, unless the value of the Rayleigh number is that corresponding to the onset of convection or just higher. Dimensionless correlating equations are developed to predict the optimal tilting angle and the heat transfer performance of the enclosure.

Existence and Incomparability of Positive Solutions for Singular Boundary Value Problems of First Order Differential Equation on Unbounded Domains

By constructing a special cone and applying the fixed point theorem of cone compression and expansion,this paper investigates the existence of positive solutions for a class of first order singular boundary value problem(BVP,for short) on unbounded domains.Moreover,an incomparable result about two positive solutions for the BVP is also obtained and an example is given to illustrate the application of the main results.