基于MPI的FDTD并行算法及其优化策略

由高性能PC机通过网络互联构成的集群(COW)并行计算系统上应用基于消息传递(Message Passing)的方式实现FDTD的并行算法,获得了足够的加速比,有效地解决了传统的FDTD方法计算电大尺寸目标电磁散射问题时的不足.通过区域分割,各个子区域在边界处与其相邻的子区域进行场值的数据传递,从而实现了FDTD算法的并行化.利用并行FDTD方法研究了电磁波的介质层的散射,结果表明并行算法和串行计算结果的一致性,并有效提高计算效率.最后还给出了对算法进行通信隐藏的优化方法,进一步提高了并行计算的效率.     

Exponential stability for uncertain neutral systems with Markov jumps

This paper deals with the global exponential stability problems for stochastic neutral Markov jump systems （MJSs） with uncertain parameters and multiple time-delays. The delays are respectively considered as constant and time varying cases, and the uncertainties are assumed to be norm bounded. By selecting appropriate Lyapunov-Krasovskii functions, it gives the sufficient condition such that the uncertain neutral MJSs are globally exponentially stochastically stable for all admissible uncertainties. The stability criteria are formulated in the form of linear matrix inequalities （LMIs）, which can be easily checked in practice. Finally, two numerical examples are exploited to illustrate the effectiveness of the developed techniques.     

基于改进的基因表达式编程算法在作业车间调度问题中的应用

文章提出一种新颖的方法一改进的基因表达式编程算法来求解作业车间调度问题。作业车间调度问题是许多实际生产调度问题的简化模型,基因表达式编程算法结合了遗传算法和遗传编程的优点,具有更强的解决问题能力,对基因表达式编程算法进行改进使其在作业车间调度问题的应用上更加有效;最后应用一个实例来验证提出方法的有效性。     

基于事件通知服务的RFID数据处理框架

RFID技术能够实现物理对象的实时标识、定位和监控,为了达到这个目标,必须能够高效地合成RFID基本事件并且有效地发布信息.RFID应用的多样化又需要一个能够通用的RFID数据处理框架.文中提出一个基于事件通知服务的RFID数据处理框架,并设计了一种基于匹配树的RFID复杂事件检测方法应用于该框架.通过对某汽车企业制造过程用例分析,来说明本框架的应用可行性.     

基于PLC的ALFA分油机控制系统研究

采用当今先进的PLC技术,对自动排渣分油机控制系统进行了全面改造,用软件取代凸轮控制器、定时器等硬件设备,降低了系统的控制成本和能源消耗,提高了系统的可靠性,增加了系统防止误报警等功能.     

云计算技术在区域安全通信中的应用

随着互联网技术的不断发展,网络已成为社会经济发展的重要支撑工具。然而,受限于传统通信技术的约束,网络通信信息存在被共享、泄露等风险。基于云计算技术的区域安全通信技术可以有效解决无线通信技术按身份分配不同通信权限的问题,用户拥有“普通域”与“安全域”功能,以保证通信网络的安全。文中以云计算技术的概念为切入点,阐述了云计算技术在区域通信中的应用价值,最后提出了构建基于云计算区域安全通信系统的具体方案,并通过实验验证了该系统具有良好的应用性能。     

2D Bi2O2Te Semiconductor with Single-Crystal Native Oxide Layer

Following logic in the silicon semiconductor industry, the existence of native oxide and suitable fabrication technology is essential for 2D semiconductors in planar integronics, which are surface-sensitive to typical coating technologies. To date, very few types of integronics are found to possess this feature. Herein, the 2D Bi₂O₂Te developed recently is reported to possess large-area synthesis and controllable thermal oxidation behavior toward single-crystal native oxides. This shows that surface-adsorbed oxygen atoms are inclined to penetrate across [Bi₂O₂]_n²ⁿ⁺ layers and bond with the underlying [Te]_n²ⁿ⁻ at elevated temperatures, transforming directly into [TeO₄]_n²ⁿ⁻ with the basic architecture remaining stable. The oxide can be adjusted to form in an accurate layer-by-layer manner with a low-stress sharp interface. The native oxide Bi₂TeO₆ layer (bandgap of ≈2.9 eV) exhibits visible-light transparency and is compatible with wet-chemical selective etching technology. These advances demonstrate the potential of Bi₂O₂Te in planar-integrated functional nanoelectronics such as tunnel junction devices, field-effect transistors, and memristors.     

A 2.20 eV Bandgap Polymer Donor for Efficient Colorful Semitransparent Organic Solar Cells

Semitransparent organic solar cells (ST-OSCs) have attracted increasing attention due to their promising prospect in building-integrated photovoltaics. Generally, efficient ST-OSCs with good average visible transmittance (AVT) can be realized by developing active layer materials with light absorption far from the visible light range. Herein, the development of ultrawide bandgap polymer donors with near-ultraviolet absorption, paired with near-infrared acceptors, is proposed to achieve high-performance ST-OSCs. The key points for the design of ultrawide bandgap polymers include constructing donor–donor type conjugated skeleton, suppressing the quinoidal resonance effect, and minimizing the twist of conjugated skeleton via noncovalent conformational locks. As a proof of concept, a polymer named PBOF with an optical bandgap of 2.20 eV is synthesized, which exhibited largely reduced overlap with the human eye photopic response spectrum and afforded a power conversion efficiency (PCE) of 16.40% in opaque device. As a result, ST-OSCs with a PCE over 10% and an AVT over 30% are achieved without optical modulation. Moreover, colorful ST-OSCs with visual aesthetics can be achieved by tuning the donor/acceptor weight ratio in active layer benefiting from the ultrawide bandgap nature of PBOF. This study demonstrates the great potential of ultrawide bandgap polymers for efficient colorful ST-OSCs.     

Design techniques for voltage-to-time converters with nonlinearity emphasis

This paper provides an in-depth treatment of voltage-to-time converters (VTCs) for time-based signal processing with a nonlinearity emphasis. The need for VTCs in deployment of time-based techniques for high-speed or high-resolution analog-to-digital converters is investigated. It is followed with the classification of VTCs. A detailed treatment of the principle, topology, operation, and design consideration of variable-slope (VS) and constant-slope (CS) VTCs is provided. The nonlinearity of VS-VTCs and that of CS-VTCs are analyzed in detail analytically. It is shown that VS-VTCs is inherently nonlinear while CS-VTCs is intrinsically linear. Factors contributing to the nonlinearity of these VTCs are investigated. VS-VTCs and CS-VTCs studied are designed in TSMC 130 nm 1.2 V CMOS and analyzed using Spectre from Cadence Design Systems with BSIM3.3 device models. A good agreement between simulation and analytical results is obtained. The average gain of the VS-VTC is 4.4 times that of the CS-VTC. The 2nd and 3rd harmonics of the CS-VTC are significantly smaller as compared with those of the VS-VTC at the price of more power consumption.

     

数控机床操控器人机界面优化设计研究

目的控制器和显示器共同组成数控机床控制面板的整体界面,是机床接受与执行命令的交互平台。从人机交互角度,聚焦于控制器的界面布局进行优化设计。方法基于人机工程学理论的优化流程,采用现场访谈、现场观察等方法,将人机工程学的理论转化为具体考核指标。结论从人机工程学的研究角度出发,结合工业设计、用户体验设计学等内容,从功能区域分区、操纵器色彩设计等方面优化数控机床控制器的界面,提高系统整体效能及使用者满意度,为数控机床系统开发设计提供参考。