虚拟交通环境中的雨滴仿真

为实现虚拟交通场景中的降雨实时仿真,设计出一种基于OpenGL的降雨仿真模型.现有雨的仿真模型主要关注降雨过程,而在虚拟交通环境中,通常还需要对雨滴在挡风玻璃上的运动进行仿真.利用OpenGL将场景渲染到纹理,运用几何方法计算雨滴粒子并将其映射到网格化的虚拟挡风玻璃平面,采用贴纹理的方法将纹理映射到虚拟挡风玻璃平面,建立了雨滴在挡风玻璃平面的仿真模型.实践表明,该方法的时间开销与场景、光照等因素无关,仅与车辆挡风玻璃上的雨滴数量相关.该方法在普通PC实验平台上渲染场景的帧速率超过25帧/秒,能够成功实现雨滴的实时仿真.     

用SUMO搭建可支持智能交通信号灯的仿真环境

文章介绍了利用SUMO平台搭建可支持智能交通信号灯的交叉路口的方法,同时利用已有正确结论验证搭建环境的有效性,为相关领域的学者提供一种可行的研究方法。     

虚拟交通场景编辑平台开发

虚拟交通场景的构建是一项繁琐的工作。在此利用Creator创建基础道路交通场景,并利用Vega虚拟仿真平台,在Visual C^--集成环境下开发了虚拟交通场景编辑系统,用户能够根据自己的需要,自行创建虚拟交通道路、虚拟汽车、交通灯及树木等,利用键盘,可以控制一台虚拟汽车在虚拟交通场景中体验虚拟驾驶过程。     

交通信息与控制虚拟仿真实验教学中心的建设

本文以我校交通信息与控制虚拟仿真实验教学中心的建设为例,按照统筹规划和优势提升的思路,构筑了专业基础课程、行业特色项目、前沿技术专题三个层次的虚拟仿真实验教学资源,形成了"先虚后实、以虚辅实、虚实结合"的创新型人才培养实验教学体系,从而提高了人才培养质量,提升了专业水平.     

计算机网络实验环境下虚拟仿真软件的运用

伴随着信息时代的到来与虚拟仿真行业的发展,虚拟仿真软件得到运用与完善。文章阐述了虚拟仿真软件的应用优势,也就计算机网络实验环境下,虚拟仿真软件应用实例及完善策略展开论述。     

基于虚拟战场环境的雷达仿真系统设计与实现

综合考虑各种体系对抗条件下的雷达作战环境,建立一套良好的开放式仿真系统.将虚拟战场环境数据引入到雷达仿真系统中,分析了各种外部环境与雷达系统的交互关系以及雷达系统的工作机制,从基于虚拟战场环境的实时动态视景数据库中调度大面积地形数据并进行分析处理,以此为依据来模拟机载雷达的工作过程.     

虚拟战场环境仿真研究

介绍了高层体系结构(HLA)对于构造分布式虚拟战场环境的优越性。提出了有利于提高仿真逼真度和增强用户沉浸感的新的战场环境描述方法。给出了分布式虚拟战场环境研究框架。探讨了分布式虚拟战场环境仿真所涉及的几个关键问题,包括联邦成员、系统结构、仿真对象模型(SOM)和联邦对象模型(FOM)。     

三维虚拟仿真研究框架

仿真平台建立的目标是为了更加方便快捷地管理事务,得到科学的结论,包括各类信息的统计分析和各种规律的模拟计算,最终做出合理的决策,例如通航管理、防洪决策等.主要探索构建三维仿真平台的总体框架,并对平台所涉及的各项关键技术进行了研究.     

移动通信虚拟仿真实验在教学中的应用

文章从传统移动通信实验教学中存在的限制因素出发,分析了将虚拟仿真软件引入课程的必要之处。通过分析得出,将移动通信虚拟仿真实验引入教学之中,使枯燥的通信原理知识更加形象,既利于教师进行课堂内容展示,也便于激发学生的学习热情,拓展学生的创新思维,进而提高移动通信课程的教学效果。     

交通信号控制虚拟实验平台设计

介绍了一种全新的交通信号控制虚拟实验平台，提出了以数据库为基础、通过网络实现的交通信号控制虚拟实验室的软件架构，并探讨了系统开发中的技术实现。     

A smart integrated environment for vehicular traffic simulation

Globally, urbanization has increased due to the availability of the facilities, jobs, and better standard of living in cities. Increase in urban population has caused increase in urban commute. The increased pressure on urban settlements has made design and optimization of urban civil infrastructure very challenging especially road transport infrastructure. Domain experts such as transportation managers, engineers, scientist, and academics need effective, easy, and readily usable computational modeling and simulation tools to conduct systematic inquiry for design and optimization of the transportation system. Free and open‐source software (FOSS) community has developed many vehicular traffic simulation software that are cost‐effective and extensible, however are difficult to use. Usually, domain experts do not have hands‐on software skills such as XML‐based interfaces, software source versioning, and build management. To bridge this gap, in our work, an integrated development environment (IDE), namely, integrated vehicular traffic simulation environment (ITE), has been developed. ITE is developed on top of an existing FOSS multimodal open‐source vehicular‐traffic simulator (MovSim). ITE includes a scenario building tool for domain experts. It could be used to model road infrastructure and vehicular traffic in an integrated manner. The tool could be used to build and experiment novel traffic infrastructures and policies. Our work helps in reducing learning curve of domain experts by providing a free and open source, easy and readily usable vehicular traffic simulation tool.     

一种恶意软件分析中检测虚拟环境的方法

安全厂商普遍使用虚拟环境来分析恶意软件,但是很多恶意软件都使用了检测虚拟机的技术来对抗对其的分析。文章介绍了3种主要的检测虚拟环境方法,给出了相应的对抗措施来防止对虚拟环境的检测。设计了一种新的基于性能比较的检查虚拟机和模拟器的方法,实验结果表明,该方法能够有效地检测出虚拟机和模拟器,如VMware软件和模拟器Qemu。     

一种基于虚拟突发的OBS网络业务疏导机制

提出了一种基于虚拟突发光突发交换的(OBS)网络业务疏导机制TG-VB(traffic grooming based on virtual burst)。作为一种多粒度动态业务疏导机制,TG-VB将常规突发通过"逻辑汇聚"组成虚拟突发,增大核心网中业务传输粒度;同时,TG-VB根据虚拟突发整体传输、整体调度的特点,为汇聚的常规突发动态地选择最优的共用传输路径。仿真结果表明,与采用传统疏导机制的OBS网络相比,TG-VB能够有效地减轻核心节点的通信处理开销,降低对网络节点端口数量的需求;在相同负载条件下,TG-VB可极大地提高波长信道利用率。     

云计算中虚拟机计算环境安全防护方案

提出了一种虚拟机计算环境的安全防护方案,该方案采用虚拟机内外监控相结合的方式对虚拟机的计算环境进行持续、动态的监控和度量,可对虚拟机进行反馈控制,保障虚拟机计算环境的安全,提升虚拟机的动态适应能力。对比现有安全防护案,该方案充分考虑了云计算中虚拟机效率损耗问题,安全性和执行效率较高,适用于虚拟计算环境。     

Priority shaping of traffic streams sharing a policed virtual path in an ATM network

Traffic streams with differing service requirements, sharing a single contract for use of a policed virtual path in an ATM network, may be jointly shaped to make the best use of bandwidth available in the path. The shaper may use the information about the network policer to perform self-policing with a form of priority service to ensure satisfactory levels of cell loss and delay for both real-time and non-real-time traffic. Two such shapers are considered assuming a mean bit-rate contract with the network in which a leaky-bucket mechanism performs the policing function. The performance of the shapers is analysed using Markov-modulated models of bursty traffic sources and stochastic fluid methods, and the analytical results are corroborated by simulations. The choice of the shaper type and optimization of the shaper design parameters are discussed using correlated and non-correlated source models.     

A mode transformation algorithm based on traffic prediction in virtual multi‐OLT PON

In this paper, a mode transformation algorithm based on traffic prediction in virtual multiple optical line terminal (OLT) passive optical network (PON) is proposed. By proposing exponential smoothing algorithm based on weight update (WU‐ESA), user traffic is predicted well. WU‐ESA is a combination of two algorithms: exponential smoothing algorithm (ESA) and genetic algorithm (GA). The weight in ESA is optimized by GA based on real‐number encoding. By setting two periods, GA part and ESA part can be separated effectively. By presenting elastic packing algorithm (EPA), the load balance problem in virtual multi‐OLT PON is solved. EPA is implemented based on WU‐ESA. By the simulation and analysis, the effectiveness of the proposed algorithms is demonstrated. Compared with traditional mode transformation algorithm, EPA shows good performances in delay, throughput, and packet loss. Compared with traditional mode transformation algorithm, the EPA makes the packet loss decrease by at least 5% when the system load is greater than 0.9. Meanwhile, the delay of the two subsystems can be kept at a relatively balanced level by the implement of EPA. For throughput, the use of EPA improves the throughput by 20% when the system load is high.     

基于单片机的交通灯控制系统的设计与仿真

随着时代的不断发展,人们生活水平越来越高,至2013年底,据不完全统计,我国机动车数量约为3亿辆,这一情况给我过交通系统带来了巨大的挑战。政府部门面对这一情况,想通过扩宽道路、加大道路修建以及诸多高科技手段来减轻交通方面的压力,但是这些方式只能缓解一时之急,却不是长久之计。笔者认为,通过控制交通信号灯来改善目前机动车给交通系统带来的压力,才是解决该问题长久有效的方法。     

基于虚拟设备驱动程序的转台实时控制系统

在对Win9x平台工作特点分析的基础上,研究了在Win9x平台下进行实时控制编程的关键技术—外部定时时钟编程、虚拟设备驱动程序VxD中断编程及VxD与应用程序的通信机制;基于此,利用VxD技术和VC 联合编程实现Win9x环境下的实时随动控制系统。长时间连续运行结果表明,系统工作稳定可靠。实践证明:把虚拟设备驱动程序技术应用于转台实时控制是可行的,且具有开发方便、事务处理能力强等优点。此研制方法对同类设备具有一定的借鉴意义。