基于VHDL的简易数字频率计的设计与实现     

曾任贤  李少义 《科技广场》2007,(11):230-231

针对复杂大规模可编程器件的特点,提出了一种新的数字频率计的实现方法。在MAXPLUSII开发软件环境下,采用硬件编程语言VHDL,实现了数字频率计的设计。经过仿真,并下载验证,能够实现测频功能。  相似文献   

Adding immersive virtual reality to a science lab simulation causes more presence but less learning     

《Learning and Instruction》2019

Virtual reality (VR) is predicted to create a paradigm shift in education and training, but there is little empirical evidence of its educational value. The main objectives of this study were to determine the consequences of adding immersive VR to virtual learning simulations, and to investigate whether the principles of multimedia learning generalize to immersive VR. Furthermore, electroencephalogram (EEG) was used to obtain a direct measure of cognitive processing during learning. A sample of 52 university students participated in a 2 × 2 experimental cross-panel design wherein students learned from a science simulation via a desktop display (PC) or a head-mounted display (VR); and the simulations contained on-screen text or on-screen text with narration. Across both text versions, students reported being more present in the VR condition (d = 1.30); but they learned less (d = 0.80), and had significantly higher cognitive load based on the EEG measure (d = 0.59). In spite of its motivating properties (as reflected in presence ratings), learning science in VR may overload and distract the learner (as reflected in EEG measures of cognitive load), resulting in less opportunity to build learning outcomes (as reflected in poorer learning outcome test performance).  相似文献   

独立学院基础会计模拟实验教学研究——以XX学院为例     

王明惠 《襄樊职业技术学院学报》2011,10(6):99-102

以问卷调查、统计分析为基础,揭示独立学院基础会计模拟实验教学的现状及存在的问题,并从完善课程设置、改进创新实验教学方法、强化师资队伍建设和加快实验室建设等方面提出基础会计模拟试验教学改革对策。  相似文献   

A method of providing accurate velocity feedback of performance on an instrumented kayak ergometer     

Mickaël Begon  Olivier Mourasse  Patrick Lacouture 《Sports Engineering》2009,11(2):57-65

On a kayak ergometer, an accurate simulation of the athlete-paddle-kayak system kinematics is essential for analysing the relationship between technique and performance. The purpose of this study was to establish a strong relationship between performances on flatwater and performances on an ergometer by means of propulsive force measurement and drag models. Two trials were performed by 12 kayakers in which they were first timed over 250 m of flatwater kayaking (the reference test) and were then asked to perform a trial of the same duration on the ergometer with the same perceived physical exertion. Three techniques for measuring propulsive force and three drag models generated nine combinations, which were all evaluated for their ability to estimate kayak velocity. For each combination, the distance covered by the athlete on the ergometer was simulated. A kayakers’ ergometer ranking was based on the average velocity in the ergometer trial. Both distance and ranking were compared to the on-water results. The simulation with the best combination of force measurement and drag model gave an accurate estimate of distance (253 ± 10.5 vs. 250 m) and ranking compared to the reference test.  相似文献   

基于增量电导法的光伏最大功率跟踪的仿真研究     

张晓航  李凯  张卡 《环球赛鸽科技》2015,(18)

介绍了光伏电池模型的工程数学模型,并在MATLAB/SIMULINK环境下建立了光伏电池的工程仿真模型。为了能够实现光伏电池的最大功率输出,本文介绍了最大功率跟踪的原理和方法。使用增量电导法实现最大功率点跟踪。并在MATLAB/SIMULINK环境下搭建光伏发电系统的仿真模型进行了仿真。仿真结果表明,搭建的光伏电池波形以及最大功率跟踪控制的仿真结果证明了可行性,可以用于光伏发电系统的仿真研究。  相似文献   

电力系统机电暂态-电磁暂态混合仿真的研究     

张兴然 《环球赛鸽科技》2015,(18)

随着电网规模的日趋扩大,传统的机电暂态或者电磁暂态仿真软件在分析电网的运行特性时,已开始显露出各自的局限性。将两者联合起来进行混合仿真,可以较好的解决仿真的规模、速度和精度的协调问题。在分析机电暂态和电磁暂态各自的特点的基础上,文中介绍了两者接口的原理和所涉及的问题。最后,对现有的三种混合仿真的接口时序方法进行了对比分析。  相似文献   

配电网保护间隙动作过程的matlab仿真研究     

袁瑶  王治国  张龙斌 《黑龙江科技信息》2015,(16)

以电力系统配电网保护间隙的防雷过电压保护动作为研究对象,通过阐述基本的保护间隙动作原理,讨论了雷电过电压发生时保护间隙存在的问题。利用matlab中的simulink程序搭建仿真电路,建立了配电网落雷后保护间隙动作仿真模型,并对仿真结果进行分析。  相似文献   

飞行程序设计课程中案例与仿真实践结合的教学模式探索     

张剑  曹萍 《教育教学论坛》2015,(12):147-148

围绕国家"卓越工程师教育培养计划"进行飞行技术专业课程教学改革,对培养合格的飞行人才具有重要意义。由于飞行程序设计较为枯燥烦琐,课堂教学效果不理想。在教学中采用案例教学,将飞行程序设计原理与案例有机结合,并在飞行模拟机进行仿真飞行和实践验证的教学方式,使学生在飞行训练的同时掌握飞行程序设计的相关理论知识、方法和实验验证手段,提高学习兴趣,增强学生理论联系实际的能力。  相似文献   

基于OPNET的MVB总线仿真研究     

黄东  魏志强 《教育技术导刊》2011,10(1):52-54

列车网络控制技术是高速列车发展的一项关键技术.为了评估多功能车辆总线(Multiple Vehicle Bus,MVB)车辆级网络通信系统的性能,优化网络设计,采用Opnet Modeler搭建车辆级通信网络模型,包括车辆的网络拓扑结构模型、链路模型、节点模型和进程模型.利用所搭建的模型,对车辆级通信网络的时延性、吞吐...  相似文献   

沿空留巷巷旁充填墙体合理尺寸优化研究     

贾建功  侯昌盛  刘辉  孟翠翠 《毕节学院学报》2011,29(4):124-128

沿空留巷实现了无煤柱开采,是煤矿生产中的重大技术改革。整体浇注巷旁充填技术是我国近年来研究和应用的先进巷旁支护技术。为了保持正常生产,就必须保证巷旁充填墙体稳定性。应用现场观测法,根据沿空留巷围岩应力随工作面推进的变化规律,研究了下区段煤体应力变化规律以及充填墙体稳定性。运用FLAC-3D数值模拟软件,模拟了4种不同宽度时的充填墙体稳定性,研究表明,墙体宽度大于或等于2m时,巷道围岩塑性区范围明显减小,支护效果较好。  相似文献