Computational Parametric Analysis of Cellular Solids with the Miura-Ori Metamaterial Geometry under Quasistatic Compressive Loads

Origami-based metamaterials have widespread application prospects in various industries including aerospace, automotive, flexible electronics, and civil engineering structures. Among the wide range of origami patterns, the fourfold tessellation known as Miura-ori is of particular attraction to engineers and designers. More specifically, researchers have proposed different 3D structures and metamaterials based on the geometric characteristics of this classic origami pattern. Herein, a computational modeling approach for the design and evaluation of 3D cellular solids with the Miura-ori metamaterial geometry which can be of zero or nonzero thicknesses is presented. To this end, first, a range of design alternatives generated based on a numerical parametric model is designed. Next, their mechanical properties and failure behavior under quasistatic axial compressive loads along three perpendicular directions are analyzed. Then, the effects of various geometric parameters on their energy absorption behavior under compression in the most appropriate direction are investigated. The findings of this study provide a basis for future experimental investigations and the potential application of such cellular solids for energy-absorbing purposes.     

Genetic interacting multiple model algorithm based on <Emphasis Type="Italic">H</Emphasis><Subscript>∞</Subscript> filter for maneuvering target tracking

In order to have a good performance for maneuvering target tracking, a genetic interacting multiple model (GIMM) algorithm based on the H _∞ filter is proposed in this paper. It introduces the H _∞ filter as model-conditional filter, which keeps its robustness by constantly adjusting parameters, to improve the performance and the precision. Meanwhile, it optimizes model probabilities using the genetic algorithm (GA), chooses sub-models which are close to true models from a set of models, adjusts the number of models and parameters in real-time, reduces excessive competition, and improves the performance of the algorithm. The simulation results indicate that, the algorithm has higher tracking accuracy and stronger robustness than the standard IMM algorithm.     

基于ACO和SPN的FMS故障诊断和可用性评价方法

提出一种柔性制造系统(FMS)的故障诊断和可用性评价方法;针对传统的随机Petri网在解决FMS故障诊断上极大受限于底层马尔科夫链规模而容易产生状态爆炸的问题,首先,将蚁群优化算法(ACO)融入随机有色网(SPN)中,提出并定义了一种能对柔性制造系统的故障进行诊断的诊断器;然后,通过马尔科夫链计算制造单元的可用性,得到FMS到诊断器的映射,从而可以得到FMS中所有可能生产过程;最后,在经典FMS可用性评价方法的基础上,引入覆盖因子,提出了一种新的对FMS生产过程进行可用性评价的方法;仿真实验显示了覆盖因子对系统可用性的影响,通过与传统方法进行比较,表明覆盖因子越大,FMS的可用性越高。     

基于模型的装备快速测试方法研究

装备测试方法主要包括测试模型建立和测试资源配置两个方面;针对当前自动测试系统存在的不足,提出了一种基于模型的装备快速测试方法;首先利用结构和参数未知的被测对象的观测数据,通过系统辨识技术建立其数学模型;在将数学模型分解为基本数学模型单元的线性组合后,再利用匹配算法建立数学模型单元与装备物理模型单元的匹配关系,即把一个黑箱逼近成一个结构和参数已知的白箱;最后根据其白箱模型建立测试需求,实现装备的快速测试;实验表明,模拟电路的匹配度高达92.22%。     

一种改进的基于二元统计的HMM分词算法

中文分词是中文信息处理的基础。基于二元统计的HMM中文分词算法表现良好,但也存在易将包含常用介、副词的词进行误拆分的问题。改进的分词算法运用逆向最大匹配的思想,在计算粗分集权重的过程中,考虑了分词的词长及词序对正确切分的有利影响。该算法首先计算出二元统计粗分模型有向边的权值,然后根据词长修定权值,最后运用最短路径法求出分词结果。实验结果表明,该算法有效的解决了过分拆分的问题,分词效果良好。     

虹桥220kV智能变电站设计与应用

智能变电站在线监测与故障诊断系统主要分为三个部分:过程层(包括现场监测终端、现场处理单元)、间隔层(包括IED及主IED)以及站控层(CAC)。其系统结构框图如下图所示,变压器油色谱在线监测、GIS局部放电监测、SF6气体、微水监测、容性设备(含避雷器监测)在线监测诊断等装置分别采集相应设备的状态数据,通过状态信息接入器汇总,再通过IEC61850协议发送到指定监控中心。虹桥220kV智能变电站的实施,提高了变电站运行的安全性和可靠性。     

Implementation and evaluation of parallel FFT on Engineering and Scientific Computation Accelerator (ESCA) architecture

The fast Fourier transform (FFT) is a fundamental kernel of many computation-intensive scientific applications.This paper deals with an implementation of the FFT on the accelerator system,a heterogeneous multi-core architecture to accelerate computation-intensive parallel computing in scientific and engineering applications.The Engineering and Scientific Computation Accelerator (ESCA) consists of a control unit and a single instruction multiple data (SIMD) processing element (PE) array,in which PEs communicate with each other via a hierarchical two-level network-on-chip (NoC) with high bandwidth and low latency.We exploit the architecture features of ESCA to implement a parallel FFT algorithm efficiently.Experimental results show that both the proposed parallel FFT algorithm and the ESCA architecture are scalable.The 16-bit fixed-point parallel FFT performance of ESCA is compared with a published work to prove the superiority of the mapping algorithm and the hardware architecture.The floating-point parallel FFT performances of ESCA are evaluated and compared with those of the IBM Cell processor and GPU to demonstrate the computing power of the ESCA system for high performance applications.     

高端磁盘阵列体系结构分析

本文介绍了两种市场主流高端磁盘阵列的体系结构,阐述了软件对提高存储服务器性能的作用,比较了两种高端磁盘阵列,最后总结了高端磁盘阵列所采用技术并预测未来发展趋势.     

Research on the group decision-making about emergency event based on network technology

In order to improve decision-making efficiency about emergency event, this paper proposes a novel concept, i.e., Agile-Delphi Method, which is an integration of agile decision and Delphi Method implicating that the decision-makers instantly deliver, respond, treat, and utilize information via Delphi process while conducting group decision-making about emergency event. The paper details the mechanism of group decision-making about emergency event based on network technology and Agile-Delphi Method. Finally, the paper conducts an empiric analysis taking the “111 event”, i.e., the liquid ammonia spill event happened on November 1, 2006 in a phosphorus chemical company in China, as an example.