A novel fault-tolerant execution model by using of mobile agents

The exponential expansion of the Internet and the widespread popularity of the World Wide Web give a challenge to experts on reliable and secure system design, e.g., e-economy applications. New paradigms are on demand and mobile agent technology is one of the features. In this paper, we propose a fault-tolerance execution model by using of mobile agents, for the purpose of consistent and correct performance with a required function under stated conditions for a specified period of time. Failures are classified into two classes based on their intrinsic different effects on mobile agents. For each kind of failure, a specified handling method is adopted. The introduction of exceptional handling method allows performance improvements during mobile agents’ execution. The behaviors of mobile agents are statistically analyzed through several key parameters, including the migration time from node to node, the life expectancy of mobile agents, and the population distribution of mobile agents, to evaluate the performance of our model. The analytical results give new theoretical insights to the fault-tolerant execution of mobile agents and show that our model outperforms the existing fault-tolerant models. Our model provides an effective way to improve the reliability of computer systems.     

数字签名技术在继电保护定值管理系统中的应用

在深入研究数字签名原理与算法的基础上,将数字签名技术应用于基于MVC架构B/S模式的继电保护定值管理系统,实现了手写签名的电子化,并保证了定值单的完整性及真伪的可验证性。通过在定值单的校核、审核、审批等一系列关键流程中数字签名的实现,使得本系统成为一个高效、完善、安全的系统。     

软件开发流程方法探析

首先对国内外软件开发理论的应用现状作了比较,然后重点分析软件系统开发流程,综合分析比较软件开发流程的各个阶段.     

基于提升格式的M带自适应小波变换

提出了基于提升格式的M带自适应小波设计方法.首先设定M带提升小波预测算子与更新算子的基本形式,然后根据提升结构及所选取的误差准则来自适应地调整预测算子及更新算子的系数,从而得到适合给定应用的最优M带提升小波.与目前对M带小波的研究相比较,采用提升格式得到的M带自适应小波既保持了提升方法的快速、简单及可直接在时(空)域上运算的特点,又具有根据实际问题设计出优化小波的优势.给出了两个3带自适应提升小波的设计实例.     

基于二进小波变换的主动轮廓模型

针对传统的主动轮廓模型对噪声敏感的缺陷,在推广梯度矢量流的基础上,提出了基于二进小波变换的改进外力场的计算方法.通过综合利用图像小波分解的高频信息,迭代计算获得其外力场,使蛇在图像的多尺度空间中搜索目标轮廓.针对蛇模型对初始轮廓的依赖性问题,给出了在一维最大熵阈值分割后的图像上获取初始轮廓点的方法,减少了人工的干预,加快了蛇的收敛速度和效果.实验结果表明该模型能有效地排除噪声的干扰,搜索凹陷轮廓,而且对脆弱轮廓有很好的逼近能力.     

协同办公自动化系统的设计与研究

本文从介绍办公自动化的概念入手,通过对OA应用现实困境的分析,就协同办公自动化系统的需求分析、设计思想和总体设计(包括信息集成平台和OA应用平台)、技术平台进行阐述、分析和比较,并对未来OA的发展趋势作以预测。     

风力发电系统变桨距模糊PID控制

由于风速的随机性及气动效应的影响,变桨距风力发电系统成为多变量强非线性不确定系统.常规PID控制方法难以取得满意的控制效果,本文在介绍和分析PD型和PI型模糊控制器的基础上,通过在PD型模糊控制器上并联一个积分环节,构成风力发电系统变桨距简化模糊PID控制器.仿真结果表明,该控制系统具有较好的动静态性能及风速扰动的鲁棒性.     

One-Component Artificial Gustatory System Based on Hydrogen-Bond Organic Framework for Discrimination of Versatile Analytes

Hydrogen-bond organic frameworks (HOFs) with excellent structural and luminescent properties have emerged as a promising material for the construction of fluorescence sensors. However, designing a facile, universal and high throughput sensor with multiplex detection capacity still remains challenging. Herein, a one-component sensor array is constructed that mimics natural gustatory system for accurate and high-throughput discrimination and identification of versatile analytes. HOF as a single sensing element greatly simplifies the probe preparation in sensor array and detection procedure. Metal ions, proteins and bacteria as the model targets are rapid and accurately discriminated, presenting the universality of the system. Particularly, the system is successfully used for the classification of antibiotic mechanisms. The study expands the application scope of HOFs and provides a facile and universal system for sensing applications.     

Ultraefficient Non-Doped Deep Blue Fluorescent OLED: Achieving a High EQE of 10.17% at 1000 cd m−2 with CIEy<0.08

The pursuit for efficient deep blue material is an ever-increasing issue in organic optoelectronics field. It is a long-standing challenge to achieve high external quantum efficiency (EQE) exceed 10% at brightness of 1000 cd m⁻² with a Commission International de L'Eclairage (CIE_y) <0.08 in non-doped organic light-emitting diodes (OLEDs). Herein, this study reports a deep blue luminogen, PPITPh, by bonding phenanthro[9,10-d]imidazole moiety with m-terphenyl group via benzene bridge. The non-doped OLED based on PPITPh exhibits an exceptionally high EQE of 11.83% with a CIE coordinate of (0.15, 0.07). The EQE still maintains 10.17% at the brightness of 1000 cd m⁻², and even at a brightness as high as 10000 cd m⁻², an EQE of 7.5% is still remained, representing the record-high result among non-doped deep-blue OLEDs at 1000 cd m⁻². The unprecedented device performance is attributed to the reversed intersystem crossing process through hot exciton mechanism. Besides, the maximum EQE of orange phosphorescent OLED with PPITPh as host is 32.02%, and remains 31.17% at the brightness of 1000 cd m⁻². Such minimal efficiency roll-off demonstrates that PPITPh is also an excellent phosphorescent host material. The result offers a new design strategy for the enrichment of high-efficiency deep blue luminogen.     

Flexible Transparent Bifunctional Capacitive Sensors with Superior Areal Capacitance and Sensing Capability based on PEDOT:PSS/MXene/Ag Grid Hybrid Electrodes

Flexible transparent supercapacitors (FTSs) have aroused considerable attention. Nonetheless, balancing energy storage capability and transparency remains challenging. Herein, a new type of FTSs with both excellent energy storage and superior transparency is developed based on PEDOT:PSS/MXene/Ag grid ternary hybrid electrodes. The hybrid electrodes can synergistically utilize the high optoelectronic properties of Ag grids, the excellent capacitive performance of MXenes, and the superior chemical stability of PEDOT:PSS, thus, simultaneously demonstrating excellent optoelectronic properties (T: ≈89%, R_s: ≈39 Ω sq⁻¹), high areal specific capacitance, superior mechanical softness, and excellent anti-oxidation capability. Due to the excellent comprehensive performances of the hybrid electrodes, the resulting FTSs exhibit both high optical transparency (≈71% and ≈60%) and large areal specific capacitance (≈3.7 and ≈12 mF cm⁻²) besides superior energy storage capacity (P: 200.93, E: 0.24 µWh cm⁻²). Notably, the FTSs show not only excellent energy storage but also exceptional sensing capability, viable for human activity recognition. This is the first time to achieve FTSs that combine high transparency, excellent energy storage and good sensing all-in-one, which make them stand out from conventional flexible supercapacitors and promising for next-generation smart flexible energy storage devices.