Two CEGAR-based approaches for the safety verification of PLC-controlled plants

In this paper we address the safety analysis of chemical plants controlled by programmable logic controllers (PLCs). We consider a specification of the control program of the PLCs, extended with the specification of the dynamic plant behavior. The resulting hybrid models can be transformed to hybrid automata, for which advanced techniques for reachability analysis exist. However, the hybrid automata models are often too large to be analyzed. We propose two counterexample-guided abstraction refinement (CEGAR) approaches to keep the size of the hybrid models moderate.     

Pseudo-inversion: closure properties and decidability

We consider a pseudo-inversion operation inspired by biological events, such as DNA sequence transformations, where only parts of a string are reversed. We define the pseudo-inversion of a string \(w = uxv\) to be the set of all strings \(v^Rxu^R\), where \(uv \ne \lambda \) and consider the operation from a formal language theoretic viewpoint. We show that regular languages are closed under the pseudo-inversion operation whereas context-free languages are not. Furthermore, we study the iterated pseudo-inversion operation and show that the iterated pseudo-inversion of a context-free language is recognized by a nondeterministic reversal-bounded multicounter machine. Finally, we introduce the notion of pseudo-inversion-freeness and examine closure properties and decidability problems for regular and context-free languages. We demonstrate that pseudo-inversion-freeness is decidable in polynomial time for regular languages and undecidable for context-free languages.     

New quantum codes from dual-containing cyclic codes over finite rings

Let \(R=\mathbb {F}_{2^{m}}+u\mathbb {F}_{2^{m}}+\cdots +u^{k}\mathbb {F}_{2^{m}}\), where \(\mathbb {F}_{2^{m}}\) is the finite field with \(2^{m}\) elements, m is a positive integer, and u is an indeterminate with \(u^{k+1}=0.\) In this paper, we propose the constructions of two new families of quantum codes obtained from dual-containing cyclic codes of odd length over R. A new Gray map over R is defined, and a sufficient and necessary condition for the existence of dual-containing cyclic codes over R is given. A new family of \(2^{m}\)-ary quantum codes is obtained via the Gray map and the Calderbank–Shor–Steane construction from dual-containing cyclic codes over R. In particular, a new family of binary quantum codes is obtained via the Gray map, the trace map and the Calderbank–Shor–Steane construction from dual-containing cyclic codes over R.     

Scalable digital hardware for a trapped ion quantum computer

Quantum Information Processing - Many of the challenges of scaling quantum computer hardware lie at the interface between the qubits and the classical control signals used to manipulate them....     

基于深度图像的人体运动姿态跟踪和识别算法

由于人体运动的复杂性,现有基于低质量深度图像的三维立体姿态跟踪和识别 方法的准确性较低、鲁棒性较差。针对低质量深度图像的人体运动姿态和识别问题,本文设 计了一种基于三步搜索算法的人体运动姿态的跟踪和识别方法。该方法首先对获取的深度信 息进行分析,从而判定人体轮廓;然后通过基于深度图像的骨骼跟踪方法跟踪特定骨骼点, 并采用三步搜索算法进行运动估计,跟踪获取人体运动轨迹;最后利用获取的骨骼点坐标实 现人体运动姿态的识别。实验结果表明,该算法克服光照影响的鲁棒性较强,且能有效地提 高人体运动姿态跟踪与识别的准确性。     

基于块稀疏快速重构的MISO活跃用户集与信道联合估计

针对多用户多输入单输出（Multiple input single output, MISO)系统的用户选择与信道估计问题,引入基于用户分布式自选择的信道接入策略,设计一种新的结合该策略的时分双分复用（Time division duplex, TDD)模式数据传输帧结构。利用用户活跃模式自然稀疏性和信道冲激响应时延域稀疏性,将基站接收上行随机导频序列建模为块稀疏线性模型。基于凸松弛的l2/l1模型提出一种快速的块稀疏重构算法求解问题模型。算法首先对目标函数进行变量分裂,然后利用交替方向法对各变量进行交替更新,直至满足收敛条件。交替更新中,对于无法获得闭式解的信号变量项,采取块坐标下降法求解。计算机仿真表明,与块正交匹配追踪和块压缩采样匹配追踪比较,新算法能够在保持高重构精度的前提下获得更快的计算速度。     

GAMMA300型七自由度机械臂运动学仿真

针对机械臂的运动学问题以及运动路径的设计问题,以冗余度为1的美国ROBAI公司生产的7自由度冗余机械臂GAMMA300为具体研究对象,对七自由度机械臂进行运动学建模与仿真.利用Robotics Toolbox机器人工具箱编写该机械手的运动学程序.通过仿真实现了预定目标,验证了设计参数的正确性和可行性,为机械臂末端执行器的精确定位和轨迹规划提供了理论依据.对于冗余机械臂一般逆运动学封闭解的研究有一定的实用价值.     

基于SAM-CS和SOFM的胃上皮肿瘤细胞图像识别

针对胃上皮肿瘤细胞图像(以下简称肿瘤细胞图像)黏结严重和信息冗余的特点,提出了一种将自适应观测矩阵的压缩感知(SAM-CS)和自组织特征映射(SOFM)神经网络相结合的算法。该算法将肿瘤细胞图像拉成列向量,然后利用通过自适应过程产生的观测矩阵,基于压缩感知理论对图像信息进行观测,产生线性观测向量,最后利用SOFM神经网络的学习算法对观测向量进行训练和分类,实现对肿瘤细胞图像的识别。实验表明,相比常用算法,该算法至少提高了4.2%的识别准确率和5.7%的运算速度。     

高效智能厨房设计研究

智能家居的设计越来越深入人心,它使人们的家居环境更舒适更加人性化,它不但提高了人们的生活品质,而且让人们从繁重的家务中脱离出来。文章以提高厨房的工作效率为目的,透过分析传统厨房设计的缺陷,提出高效智能厨房需要解决的问题,将智能化设计应用于厨房设计中,实现具有高效的智能化厨房。