儵忽鑿竅( 一)

由於儵、忽的美好願望改變這個自然 清虛的本質，使混沌這時變得面目全非，原來真正的混沌被破壞了，清虛自然終於消失

選擇權之評價理論

漫談選擇權之評價理論
http://www.polaris.com.tw/polaris/www/goods/%E5%89%B5%E5%88%8A%E8%99%9F/Web/Forum.pdf#search=%22%E9%81%B8%E6%93%87%E6%AC%8A%E8%A9%95%E5%83%B9%E7%90%86%E8%AB%96%22

Geometric Brownian motion
http://en.wikipedia.org/wiki/Geometric_Brownian_motion

ITO Process
http://galton.uchicago.edu/~lalley/Courses/390/Lecture6.pdf#search=%22Ito%20process%22

Chaos and Fractals in Financial Markets
http://orlingrabbe.com/chaos1.htm

Excel VBA Model
http://www.programurl.com/software-excel-vba-models-combo-set-downloadnow.html

ReactOS - An open source implementation of WinNT

ReactOS is a project to develop a free software/open-source operating system that is binary-compatible with Microsoft Windows NT/XP

http://www.reactos.org/

HeidiSQL - tools for MySQL

HeidiSQL is an easy-to-use interface and a "working-horse" for web-developers using the popular MySQL-Database. It allows you to manage and browse your databases and tables from an intuitive Windows® interface.

With HeidiSQL you will also be able to

* generate nice SQL-exports

* synchronize tables between two databases

�P manage user-privileges

�P import text-files

�P and much more

http://www.heidisql.com/

MMConvert - Opensource multimedia format converter

MMConvert is a multimedia format converter, using it, you can convert media file from one format into another one. such as convert avi to wmv and so on. it can support any source format with relevant DirectShow decoder, Now supported destination format includes: asf, wmv, wma, avi, mp3, wav, mkv, mka, ogg and ape etc.

Links: http://mmconvert.sourceforge.net/en_us/

NOT IN <> NOT EXISTS

如果你的数据库设计在任何一栏中都允许NULL值的话，你需要了解一下，在你的查询语句中，不同的子句是怎样对待这一问题的。
从表面上看，可能显示出这样的情形，即SQL子句IN与EXISTS可以互换。然而，在处理NULL值时，它们的表现截然不同，而且得到的结果也很可能不同。问题源于这样一个事实，即在一个Oracle数据库中，一个NULL值意味着未知，因此，对一个NULL值的任何比较或操作也都是无效的，而任何返回NULL的测试也都被忽视了。例如，以下这些查询语句都不会返回任何行：
select 'true' from dual where 1 = null;
select 'true' from dual where 1 != null;

值1既不能说是等于NULL，也不能说是不等于NULL。只有是NULL的时候才会返回一个真正的NULL值并返回一行。
select 'true' from dual where 1 is null;
select 'true' from dual where null is null;

当你使用IN时，相当于你告诉SQL接受一个值，并将它与某个清单中使用＝的每一个值或一组值进行比较。只要存在了任何NULL值，就不会返回任何行，纵使两个值都是NULL也不行。
select 'true' from dual where null in (null);
select 'true' from dual where (null,null) in ((null,null));
select 'true' from dual where (1,null) in ((1,null));

一个IN从功能上等同于＝ANY子句：
select 'true' from dual where null = ANY (null);
select 'true' from dual where (null,null) = ANY ((null,null));
select 'true' from dual where (1,null) = ANY ((1,null));

当你使用一种与EXISTS等同的格式时，SQL会计算行数，却忽视子查询中的值，就算你返回NULL也一样。
select 'true' from dual where exists (select null from dual);
select 'true' from dual where exists (select 0 from dual where null is null);

从逻辑上看，IN与EXISTS是一样的。IN子句在外部查询中比较子查询返回的值，并过滤掉行；EXISTS子句在子查询内部比较那些值并过滤掉行。在出现NULL值的情况下，作为结果而出现的那些行是相同的。
selectename from emp where empno in (select mgr from emp);
selectename from emp e where exists (select 0 from emp where mgr = e.empno);

不过，当逻辑被转变成使用NOT　IN和NOT　EXISTS时，问题就出现了，这两个语句会返回不同的行（第一个查询会返回0行；第二个返回意想的数据－它们是不同的查询）：
selectename from emp where empno not in (select mgr from emp);
selectename from emp e where not exists (select 0 from emp where mgr =e.empno);

NOT　IN子句实际上与用＝比较每一个值相同，如果任何一个测试为FALSE　或NULL的话，它就会失败。例如:
select 'true' from dual where 1 not in (null,2);
select 'true' from dual where 1 != null and 1 != 2;
select 'true' from dual where (1,2) not in ((2,3),(2,null));
select 'true' from dual where (1,null) not in ((1,2),(2,3));

这些查询不会返回任何行。而第二个更值得怀疑，1！＝NULL是NULL，因此对整个WHERE条件来说都是错误的。它们会这样运行：
select 'true' from dual where 1 not in (2,3);
select 'true' from dual where 1 != 2 and 1 != 3;

只要你在结果中阻止系统返回NULL，在这之前你还是可以使用NOT　IN查询（同样，这些都能运行，不过我假定empno不是NULL，在我们这个案例中，这是一个很好的假设）:
selectename from emp where empno not in (select mgr from emp where mgr is not null);
selectename from emp where empno not in (select nvl(mgr,0) from emp);

由于了解了IN，EXISTS，NOT　IN，以及NOT　EXISTS之间的差别，当一个子查询的数据中出现NULL时，你就可以避免一个非常普遍的问题了。

HOWTO setup FreeNx on Fedora

FreeNX provide amazing performance for remote desktop. This website tell us how to install it on Fedora.

http://fedoranews.org/contributors/rick_stout/freenx/

Upgrade FC4 to FC5

I find some following resources from the web:

http://www.linuxsky.net/html/200604/2635.html
http://www.brandonhutchinson.com/Upgrading_Red_Hat_Linux_with_yum.html


ext3 upgrade:
http://archives.free.net.ph/message/20060508.023346.df45ee08.en.html

ajax4jsf: Project Home Page

ajax4jsf: Project Home Page AJAX for JSF

The Unofficial Fedora FAQ

Just found a useful information about Fedora: The Unofficial Fedora FAQ

DBDesigner 4

fabFORCE.net's DBDesigner 4 is a Open Source visual database design system that integrates database design, modeling, creation and maintenance into a single, seamless environment.It combines professional features and a clear and simple user interface to offer the most efficient way to handle your databases.
It is developed and optimized for the open source MySQL-Database to support MySQL users with a powerful and free available design tool.

Paint .NET

Paint.NET is image and photo manipulation software written in C#. It started development at Washington State University as an undergraduate senior design project mentored by Microsoft. Source is available upon request.

Gentoo Linux Taiwan -- 用 GIMP 畫 CG（漫畫篇）

A good article for using GIMP:
Gentoo Linux Taiwan -- 用 GIMP 畫 CG（漫畫篇）

QEMU

Today I found a open source processor emulator on the web which called: QEMU.
It provide similar function of VMWare.