Stability region bifurcations of nonlinear autonomous dynamical systems: Type‐zero saddle‐node bifurcations

The behavior of stability regions of nonlinear autonomous dynamical systems subjected to parameter variation is studied in this paper. In particular, the behavior of stability regions and stability boundaries when the system undergoes a type‐zero sadle‐node bifurcation on the stability boundary is investigated in this paper. It is shown that the stability regions suffer drastic changes with parameter variation if type‐zero saddle‐node bifurcations occur on the stability boundary. A complete characterization of these changes in the neighborhood of a type‐zero saddle‐node bifurcation value is presented in this paper. Copyright © 2010 John Wiley & Sons, Ltd.     

最优线性联想记忆网络的γ谱解析

利用最优线性联想记忆神经网络,对γ能谱进行了定性识别与定量分析,成功克服了传统解谱方法对操作人员要求高、运算速度慢、不能准确识别有重峰的复杂γ能谱等问题.采用全谱输入法,利用整个能谱的信息,降低了对探测器能量分辨率的要求,避免了寻峰、能量刻度与效率刻度,准确识别了单核素能谱与几种核素的混合能谱,从而成为一种行之有效的解谱手段,为高性能便携式探测器解谱软件的开发提供了依据.     

A novel method for analyzing dominant oscillation mode based on improved EMD and signal energy algorithm

In this paper,a novel method that integrates the improved empirical mode decomposition(EMD)and signal energy algorithm is proposed to estimate the dominant oscillation parameters and corresponding mode shape.Firstly,the EMD with symmetrical extrema extension(SEE)is utilized to decompose the measured data from wide area measurement system(WAMS)into a finite set of intrinsic mode functions(IMFs).Then,the signal energy algorithm is used to calculate the approximate oscillation parameters of the IMFs.The nodes ...     

Improving bi-manual 3D input in CAD modelling by part rotation optimisation

Part modelling in a CAD environment requires a bi-manual 3D input interface to fully exploit its potentialities. In this research we provide extensive user tests on bi-manual modelling using different devices to control 3D model’s rotation. Our results suggest that a simple trackball device is effective when the user task is mostly limited to rotation control (i.e. when modelling parts in a CAD environment). In our tests, performances are even better than those achieved with a specifically designed device. Since the task of rotating a CAD part often shows the need of flipping the controlled object, we introduce a non linear transfer function which combines the precision of a zero order control mode with the ability to recognise fast movements. This new modality shows a significant improvement in the user’s performances and candidates itself for integration in next generation CAD interfaces.     

Dendritic Cells and Multiple Sclerosis: Disease,Tolerance and Therapy

Multiple sclerosis (MS) is a devastating neurological disease that predominantly affects young adults resulting in severe personal and economic impact. The majority of therapies for this disease were developed in, or are beneficial in experimental autoimmune encephalomyelitis (EAE), the animal model of MS. While known to target adaptive anti-CNS immune responses, they also target, the innate immune arm. This mini-review focuses on the role of dendritic cells (DCs), the professional antigen presenting cells of the innate immune system. The evidence for a role for DCs in the appropriate regulation of anti-CNS autoimmune responses and their role in MS disease susceptibility and possible therapeutic utility are discussed. Additionally, the current controversy regarding the evidence for the presence of functional DCs in the normal CNS is reviewed. Furthermore, the role of CNS DCs and potential routes of their intercourse between the CNS and cervical lymph nodes are considered. Finally, the future role that this nexus between the CNS and the cervical lymph nodes might play in site directed molecular and cellular therapy for MS is outlined.     

检验设备数据导入的设计探讨

综合性的质检机构拥有各类型检验检测仪器数量至少在700台（套）以上，检验人员依靠各检验检测仪器对样品进行检验并出具检验数据。目前在我国质检机构中均采用检验员将检验数据记录在原始记录卡上，然后再录入到管理信息系统中的方式。在此过程中忽略了部分计算机控制的仪器的网络通讯功能。质检机构如何有效的进行检验数据的采集和录入是检验机构效率提升的关键。接下来，本文将分析研究检验设备数据和信息导入的应用和设计。     

型钢混凝土节点抗裂计算分析

介绍了目前广泛应用于实际工程的6类SRC柱—RC梁节点构造形式,对各类节点的受力性能和破坏机理进行了全面的分析,同时研究了SRC柱—RC梁框架节点核心区的抗裂机理,并通过ABAQUS有限元软件计算,建立了节点核心区的抗裂承载力计算公式。     

Assessment of conservative load transfer for fluid–solid interface with non‐matching meshes

We present a detailed comparative study of three conservative schemes used to transfer interface loads in fluid–solid interaction simulations involving non‐matching meshes. The three load transfer schemes investigated are the node‐projection scheme, the quadrature‐projection scheme and the common‐refinement based scheme. The accuracy associated with these schemes is assessed with the aid of 2‐D fluid–solid interaction problems of increasing complexity. This includes a static load transfer and three transient problems, namely, elastic piston, superseismic shock and flexible inhibitor involving large deformations. We show how the load transfer schemes may affect the accuracy of the solutions along the fluid–solid interface and in the fluid and solid domains. We introduce a grid mismatching function which correlates well with the errors of the traditional load transfer schemes. We also compare the computational costs of these load transfer schemes. Copyright © 2005 John Wiley & Sons, Ltd.     

双差分输入全对称全互补直流功率放大电路的分析与设计

中通过对一款双差分输入全对称全互补直流功率放大器进行分析，总结出了这一类电路的工作原理，并探讨了这类电路的基本设计方法和设计原则．另外对直流功放的改进型即CL型功率放大电路的基本概念、优点以及在设计中应该注意的问题也做了一定的阐述。     

An iterative learning control theory for a class of nonlinear dynamic systems

An iterative learning control scheme is presented for a class of nonlinear dynamic systems which includes holonomic systems as its subset. The control scheme is composed of two types of control methodology: a linear feedback mechanism and a feedforward learning strategy. At each iteration, the linear feedback provides stability of the system and keeps its state errors within uniform bounds. The iterative learning rule, on the other hand, tracks the entire span of a reference input over a sequence of iterations. The proposed learning control scheme takes into account the dominant system dynamics in its update algorithm in the form of scaled feedback errors. In contrast to many other learning control techniques, the proposed learning algorithm neither uses derivative terms of feedback errors nor assumes external input perturbations as a prerequisite. The convergence proof of the proposed learning scheme is given under minor conditions on the system parameters.