半导体光开关工作电流和速率的理论分析

本文从载流子连续性方程出发，采用半导体双异质结概念，从理论上推出了计算半导体光波导开关工作电流和速率的理论公式，为器件选取工作电流和提高开关速率提供了理论依据．     

Trochilidae:面向众核平台的高性能轻量级虚拟机监控器

虚拟化技术在云计算中广泛应用。传统虚拟化技术对操作系统的一些操作都进行了捕捉与封装,使其越来越复杂,同时也影响了操作系统的性能。针对众核平台的发展趋势和特点,面向众核平台设计并实现了一个轻量级的高性能虚拟机监控器——蜂鸟(Trochilidae)。多操作系统可以同时运行在此虚拟机监控器之上,同时对操作系统性能无损失。在提供传统虚拟机监控器功能的基础上,蜂鸟的代码量仅4000行左右(包括汇编与C代码),降低了系统的复杂度,便于系统的维护与调试。     

通用型安全操作系统解决方案浅析

在信息安全领域,随着攻击技术的不断升级和数据泄露事件的激增,业界越来越重视服务器操作系统的安全问题。文章从等级保护安全操作系统研究入手,介绍了两种安全操作系统解决方案,对比了通用型安全操作系统相比传统自主研发的安全操作系统的优势所在。文中重点阐述了通用型安全操作系统解决方案的技术优势和实现原理,结合增强型DTE、RBAC、BLP三种访问控制安全模型,重构操作系统的安全子系统(SSOOS),动态、透明提升操作系统安全等级,以实现通用型安全操作系统的解决方案。     

DCS操作站仿真研究

针对DCS(Distributed Control System,集散控制系统)操作站仿真中维护升级困难、实时性差的问题,本文采用接口定义与代码实现分离的设计原则来简化维护升级步骤,提出委托代理的更新方法来提高系统实时性,最后利用MFC设计实现软件。     

酒店信息搜索系统设计

讲解使用Google Map API确定酒店地理位置,并对酒店周边的信息进行搜索。     

μC／OS—Ⅲ在Cortex—M3处理器上的移植

为了将μC／OS-Ⅲ移植到Cortex—M3处理器上,选用RealView MDK作为软件开发平台,针对Cortex—M3处理器特性编写了移植所需的C语言和汇编语言源代码,并验证了移植的正确性。移植后的μC／OS-Ⅲ能够稳定运行于Cortex～M3处理器上。该移植对大部分Cortex—M3处理器具有通用性,对其他架构处理器的μC／OS-Ⅲ移植具有参考作用。     

An improved bacterial foraging algorithm for combined static/dynamic environmental economic dispatch

Economic dispatch is carried out at the energy control center to find out the optimal output of thermal generating units such that power balance criterion is met, unit operating limits are satisfied and the fuel cost is minimized. With growing environmental awareness and strict government regulations throughout the world, it has become essential to optimize not only the total fuel cost but also the harmful emissions, both, under static as well as dynamic conditions. The static environment economic dispatch finds the optimal output of generating units for a fixed load demand at a given time, while the dynamic environmental economic dispatch schedules the output of online generators with changing power demands over a certain time period (normally one day) so as to minimize these two conflicting objectives, simultaneously. In this paper, the price penalty factor approach is employed for simultaneous minimization of cost and emission. The generator ramp rate constraints, non-convex and discontinuous nature of cost function and the large number of generators in practical power plants, make this problem very difficult to solve. Here, a fuzzy ranking approach is employed to identify the solution which offers the best compromise between cost and emission objectives.     

Infants' sensitivity to optical flow for controlling posture.

Infants' sensitivity to optical flow for controlling sitting and standing was tested using a "moving room" in which all of the walls moved together, or only the side walls or front wall moved. Two questions motivated this research. (a) is the optical flow necessary for inducing postural compensations spatially distributed in the optic array? (b) Do visually induced compensations follow a developmental progression, or alternatively, emerge all at once? Experiment 1 was designed to test postural compensations by 14-month-old infants capable of standing in the moving room. Experiment 2 was designed to test postural compensations by 5- to 9-month-old infants who were passively supported while sitting in the moving room. The results revealed that partial flow is generally sufficient for inducing postural compensations, but that the amplitude and consistency of the response depend on the location of the flow in the optic array. In addition, there was evidence suggesting that compensatory responses become increasingly systematic during the second half of the first year. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

实时系统安全评估机制及其仿真研究

研究了嵌入式实时系统弹性应对策略中的安全评估机制。工业控制系统中存在嵌入系统,现有嵌入式系统无法动态掌握系统运行时的安全状况并无法做出响应的问题。为了保证嵌入系统安全运行,提出了实时系统的弹性应对策略以改善系统的安全性,设计并实现了模式匹配的嵌入式实时系统安全等级评估模块,可以实现动态实时的系统安全状况评价,并为系统动态配置安全策略提供了决策支持。采用RT-Linux建立了仿真评估环境,对安全等级评估系统的性能进行了仿真测试。测试结果表明安全等级评估模块的系统开销很小,能够有效的保障嵌入式实时系统的安全运行,具有广泛的应用价值和前景。     

多虚拟机环境下磁盘写优化机制

在虚拟化环境下,如何在写直达法和写回法之间做出权衡以使系统既具有较好的可靠性又具有较高的磁盘读写性能,是一个亟待解决的问题。本文提出了基于XEN的兼有写直达法和写回法优点的磁盘数据写操作方法。通过修改虚拟机块设备前后端驱动程序,在虚拟机管理器中为每个虚拟机建立块级别的虚拟机磁盘缓存。虚拟机中的应用程序均采取写直达的方式,将数据直接写到位于虚拟机管理器的虚拟机磁盘缓存中。结果表明,该机制能为虚拟机提供高效率的磁盘读写操作,同时,在虚拟机系统突然宕机时也能保证用户数据的完整性和可靠性。