基于复杂网络的航空制造供应链关键节点识别研究

随着不稳定因素的增加以及航空制造供应链的参与主体增多，航空制造供应链的管理所面临的风险也随之增大。因此针对航空制造供应链网络的风险管理，以复杂网络为工具研究供应链网络中的关键节点识别问题，从而帮助航空供应链提升抗风险能力。通过分析我国航空制造供应链网络现状和特点，提出供应链形成机制并划分供应链层级，对航空制造供应链进行构建及指标界定，对度中心性、介数中心性、接近中心性三种经典中心性算法以及传统K-Shell 分解算法进行加权改进；结合熵值-TOPSIS 法提出一种针对加权网络的供应链关键节点识别算法——WKC 算法，通过构造网络来进行算例分析，验证该种算法的有效性。结果表明：本文提出的WKC 算法原理科学、计算复杂度较低，为航空制造等高端装备制造业供应链的风险管理提供了一定的参考。     

Virtual Reality-based Teleoperation with Robustness Against Modeling Errors

This article investigates virtual reality (VR)-based teleoperation with robustness against modeling errors. VR technology is an effective way to overcome the large time delay during space robot teleoperation. However, it depends highly on the accuracy of model. Model errors between the virtual and real environment exist inevitably. The existing way to deal with the problem is by means of either model matching or robot compliance control. As distinct from the existing methods, this article tries to combine model matching and robot compliance control. On one hand, the status of the virtual robot is corrected by using the position sensor data from robot joints before and during teleoperation, and the pose of the virtually manipulated object is obtained with visual recognition technology. On the other hand, compliance control algorithms of impedance control based on joint torque sensors and hybrid position/force control based on a wrist sensor have been executed in order to eliminate the small sustaining model errors. A VR-based teleoperation system of satellite on-orbit self-serving is built up. In order to verify the proposed method, an experiment deploying the solar panel troubled by malfunction is carried out through teleoperation. It shows that the large model errors are removed with the model matching method and the adopted compliance control is robust against the remaining small model errors.     

在PN码捕获中门限判决对T_(MA)性能影响的分析

文章比较了在单径加性高斯白噪声(AWGN)无衰落信道环境下,利用匹配滤波器(MF)捕获方法,对不同的门限比较判决准则对系统平均捕获时间(TMA)性能的影响进行了分析;同时给出了不同门限值时系统的平均捕获时间的仿真结果,并对结果进行讨论,得出各种门限设置准则的应用环境,为捕获系统的设计与实现提供参考。     

"恭城模式"的经济解读

"恭城模式"经过20多年的探索,发展成"养殖-沼气-种植"三位一体的生态农业模式。"恭城模式"是发展生态农业的成功范例。文章从经济角度解读"恭城模式",得出欠发达地区发展生态经济的启示。     

汽车消声器筒体翻边工艺及模具设计

主要介绍了汽车消声器筒体翻边件坯料、翻边力的设计计算以及翻边模的设计方法     

M/G/1排队系统性能梯度估计的非标准分析法

如何估计系统性能梯度是离散事件动态系统研究中的一个重要问题.系统性能对于概率参数的梯度无法用传统的摄动分析法来估计,我们从非标准分析的角度提出了一种基于Dirac δ函数的摄动分析算法,分析了相应估计量的强相合性和渐近无偏性.新算法在实现过程中需要用样条函数来近似δ函数,但可以同时估计M/G/1排队系统中顾客期望系统时间和忙期期望长度对概率参数的梯度.数值实验结果表明估计量的相对误差和无偏性检验值都比较小,新算法能够很好地估计M/G/1排队系统的性能梯度.     

航电系统并行检测过程与检测设备解耦方法

航电系统在使用或升级改造过程中进行可靠性检测是必不可少的。特别是在当前批量航电系统大量投入使用的背景下，迫切需要能高效、快速、准确地对系统进行可靠性检测。由于航电系统安全性要求高，内置检测软件受限，需要外置检测设备通过航电系统指定接口进行检测，检测过程也不允许出现任何泄露等行为。检测设备与具体航电系统耦合，检测过程与具体检测设备耦合，难以实现批量航电系统并行检测。为此，通过引入逻辑检测设备，给出了一种航电系统并行检测分层框架，解决检测设备与被测系统耦合的问题，同时也保证了检测的安全性。通过逻辑检测设备、检测跳转机和被测主机上检测行为的描述，给出了一种面向通用航电系统并行检测的检测设备协同机制，解决检测过程与检测设备耦合的问题，从而支持多个航电系统并行检测。最后，实现了一个通用航电系统并行检测系统，并通过实际应用和实验对比验证所提方法的有效性。     

Adaptive mesh refinement computation of acoustic radiation from an engine intake

A block-structured adaptive mesh refinement (AMR) method was applied to the computational problem of acoustic radiation from an aeroengine intake. The aim is to improve the computational and storage efficiency in aeroengine noise prediction through reduction of computational cells. A parallel implementation of the adaptive mesh refinement algorithm was achieved using message passing interface. It combined a range of 2nd- and 4th-order spatial stencils, a 4th-order low-dissipation and low-dispersion Runge–Kutta scheme for time integration and several different interpolation methods. Both the parallel AMR algorithms and numerical issues were introduced briefly in this work. To solve the problem of acoustic radiation from an aeroengine intake, the code was extended to support body-fitted grid structures. The problem of acoustic radiation was solved with linearised Euler equations. The AMR results were compared with the previous results computed on a uniformly fine mesh to demonstrate the accuracy and the efficiency of the current AMR strategy. As the computational load of the whole adaptively refined mesh has to be balanced between nodes on-line, the parallel performance of the existing code deteriorates along with the increase of processors due to the expensive inter-nodes memory communication costs. The potential solution was suggested in the end.     

宾馆火灾风险评估初探

在分析宾馆火灾发生原因的基础上,建立了宾馆火灾危险性、火灾损失评估因素集,并运用模糊评价法对宾馆的火灾安全进行风险性和损失评价,通过评价得出建筑物所属的安全等级,从而为宾馆实施安全管理提供方向和依据。该方法的建立可用于保险公司对投保建筑的鉴别与筛选,同时也可使管理者根据该评估方法及时采取防火安全措施,以降低火灾危险性,减少火灾损失。