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The Matthew Effect

June 24th, 2009 | No Comments | Posted in Knowledges

I have found this interesting effect on “The EconomicNaturalist WHY ECONOMICS EXPLAINS ALMOST EVERYTHING”

It explains that why “the rich get richer and the poor get poorer” of the Matthe effect, so I will quote the statement from Wiki first.

The Matthew effect in sociology is the phenomenon that “the rich get richer and the poor get poorer”. Those who possess power and economic or social capital can leverage those resources to gain more power or capital. The Matthew effect results in a power law distribution of resources. The term was first coined by sociologist Robert K. Merton and takes its name from a line in the biblical Gospel of Matthew:
For the example, the book explains that why is it easier to find a partner when you already have one?. The situation begins at a man asked an attractive woman to meet at the bar at one night. When the twos met at the bar, suddendly the woman caressed his arm, gazed lovingly into his eyes and whispered frequently in his ear. The she announced her departure, asking him to meet her for coffee the next day. What happens next? Most of the women in that bar made contact with the man.

Why?
‘It’s hard to tell whether someone’s OK just by looking at him’ the woman said. But because of the fact that she, an attractive woman, was paying such close attention to a man she obviously knew well was a credible signal that he was OK.

XML-RPC vs. SOAP

June 23rd, 2009 | No Comments | Posted in Knowledges

This website describes the different between XML-RPC and SOAP in a very sample way. Any competent programmers would understand it at the first glance.
Here
This is something that shows the real different between the two ways to communicate

Feature XML-RPC SOAP
basic scalars yes yes
structs yes yes
arrays yes yes
named structs and arrays no yes
detailed fault handling yes yes
short learning curve yes no
Developers specified character set no yes (US-ASCII, UTF-8, UTF-16)
Developer defined data types no yes
Can specify recipient no yes
require client understanding no yes
message specific processing instructions no yes

Tutorial : Composite Design Pattern

June 23rd, 2009 | No Comments | Posted in Java

I have a chance to knwo Composite Design Pattern,?? so I don’t want to forget that immediately.

Composite allows a group of objects to be treated in the same way as a single instance of an object. The intent of composite is to “compose” objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions uniformly.

Composite can be used when clients should ignore the difference between compositions of objects and individual objects. If programmers find that they are using multiple objects in the same way, and often have nearly identical code to handle each of them, then composite is a good choice; it is less complex in this situation to treat primitives and composites as homogeneous.

Those are from Wiki. The most intelligent source.