turn off beep in Linux
beep is very annoying, turn it off when startup the system each time:
rmmod pcspkr
in /etc/rc.local.
Labels: Linux, Operation and Maintenance
beep is very annoying, turn it off when startup the system each time:
Labels: Linux, Operation and Maintenance
/etc/mplayer/mplayer.conf(or ~/.mplayer/config)
Labels: Linux, Operation and Maintenance
As we all known, it doesn't distinguish between uppercase and lowercase letters in Windows. In effect, I found that it's not because Windows wouldn't support case sensitive, but the FAT32 file system as well as NTFS file system wouldn't become case sensitive. When I copied some files which contain two files with the same name but different cases from a Linux file system to a FAT32 file system, it just let only one file left. In my opinion, when it recognized there was a file named "aaa" in the FAT32 file system it just replaced "aaa" with "AAA" which was recognized as the same as "aaa".(when I cp /usr/include to a FAT32 disk)
Labels: Linux, Operation and Maintenance
这篇文章主要介绍了虚拟机的概念,分类,起源,以及必要性。
Labels: virtualization
Today I've got a new LCD display which is 19 inches. Thus the resolution 1024*768 is no longer suitable for it.
Labels: Linux, Operation and Maintenance
Today I copied a text file to my mp3 but it can't recognize and displayed
Labels: Operation and Maintenance
这篇文章主要介绍了一些3D benchmarking的基础知识,例如帧率,填充率等等。
Labels: virtualization
作者比较了四种可以在Ubuntu Linux下运行的虚拟化产品:免费且开源的x86仿真器Qemu;闭源但免费的Virtual Box和VMware-Server;商业化产品Parallels Workstation。
Labels: virtualization
主要介绍了虚拟化技术以及一些已有的虚拟机产品。文章结构大致如下:虚拟化发展历史,虚拟化定义,虚拟化带来的好处,虚拟化实现技术,仿真和模拟,最后是很多虚拟化产品。
Labels: virtualization
作者针对复杂虚拟环境虚拟化中的交互式帧率提出了一个适应性显示算法。算法基于一个层次模型表示法,能在不同细节层次上来描述目标物体,而且能够用各种不同的渲染算法来绘图。算法背后的思想就是适应性地调整图像质量,以维持一个固定的用户自定义的目标帧率。作者做了约束性优化来为每一个有可能可见的物体选择细节的层次和渲染算法,目的是为了在目标成帧时间之内产生“最好” 的图像。其他已有的细节省略算法在对复杂模型的虚拟化中有着几乎难以察觉的图像质量差异,而测试结果表明该算法比起这些算法有着更稳定的帧率。
作者用到了如下两个公式:
(1)第一个公式是前提条件,第二个是需要求其做大化值的。(1)中在层次L下用R算法对物体O进行渲染所需代价是Cost(O,L,R),所有物体所需渲染代价值和要小于目标成帧时间TargetFramTime;收益Benefit(O,L,R)表示在层次L下用算法R对物体O渲染的收益,所有物体的收益之和要尽可能的大。
Cost的定义是一些启发式的规则,Benefit也是。具体地说,Cost定义如下:
作者假设每个像素所需时间与像素和物体个数成比例,Cost取C1Poly(O,L)+C2Vert(O,L)与C3Pix(O)中的较大者。C1,C2,C3对一个固定的渲染算法和机器来说是常量。Poly(O,L)代表多边形物体O在层次L上所需时间,Vert(O,L)表示顶点O在层次L上所需时间。
对于收益Benefit,定义如下:
其中,
(5)
收益就是目标物体大小,精确度,重要性因子等因素之间的乘积。而精确度定义为1-Error。
[1] T. A. Funkhouser and C. H. Sequin. Adaptive display algorithm for interactive frame rates during visualization of complex virtual environments. Computer Graphics, 27(Annual Conference Series): 247–254, 1993.
Labels: virtualization