Lesson 101April 2, 2008 11:03 pm
  
CAPTCHA is a type of challenge-response test used in computing to determine that the user is not run by a computer. The process involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human. A common type of CAPTCHA requires that the user type the letters of a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen.

The term "CAPTCHA" was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper (all of Carnegie Mellon University), and John Langford (then of IBM). It is a contrived acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart", trademarked by Carnegie Mellon University.

A CAPTCHA is sometimes described as a reverse Turing test, because it is administered by a machine and targeted to a human, in contrast to the standard Turing test that is typically administered by a human and targeted to a machine.

Lesson 101March 27, 2008 2:28 pm

Short message service is a mechanism of delivery of short messages over the mobile networks. It is a store and forward way of transmitting messages to and from mobiles. The message (text only) from the sending mobile is stored in a central short message center (SMSC) which then forwards it to the destination mobile.

The figure below shows a typical organization of network elements in a GSM network supporting SMS.

 

The SMSC (Short Message Service Center) is the entity which does the job of store and forward of messages to and from the mobile station. The SME (Short Message Entity), which is typically a mobile phone or a GSM modem, can be located in the fixed network or a mobile station, receives and sends short messages.

The SMS GMSC (SMS gateway MSC) is a gateway MSC that can also receive short messages. The gateway MSC is a mobile network’s point of contact with other networks. On receiving the short message from the short message center, GMSC uses the SS7 network to interrogate the current position of the mobile station form the HLR, the home location register.

HLR is the main database in a mobile network. It holds information of the subscription profile of the mobile and also about the routing information for the subscriber, i.e. the area (covered by a MSC) where the mobile is currently situated. The GMSC is thus able to pass on the message to the correct MSC.

MSC (Mobile Switching Center) is the entity in a GSM network which does the job of switching connections between mobile stations or between mobile stations and the fixed network.

A VLR (Visitor Location Register) corresponds to each MSC and contains temporary information about the mobile, information like mobile identification and the cell (or a group of cells) where the mobile is currently situated. Using information form the VLR the MSC is able to switch the information (short message) to the corresponding BSS (Base Station System, BSC + BTSs), which transmits the short message to the mobile. The BSS consists of transceivers, which send and receive information over the air interface, to and from the mobile station. This information is passed over the signaling channels so the mobile can receive messages even if a voice or data call is going on.

 
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Lesson 101March 14, 2008 7:14 am
 Java Platform, Enterprise Edition or Java EE is a widely used platform for server programming in the Java programming language. The Java EE Platform differs from the Standard Edition (SE) of Java in that it adds additional libraries which provide functionality to deploy fault-tolerant, distributed, multi-tier Java software, based largely on modular components running on an application server.
 
Is there a difference between Enterprise, Standard or Micro Edition?
 
Java ME (Micro Edition): Specifies several different sets of libraries (known as profiles) for devices which are sufficiently limited that supplying the full set of Java libraries would take up unacceptably large amounts of storage.
    * Java SE (Standard Edition): For general purpose use on desktop PCs, servers and similar devices.
    * Java EE (Enterprise Edition): Java SE plus various APIs useful for multi-tier client-server enterprise applications.
 
 
 
 
 
Lesson 101March 13, 2008 10:29 pm
 
Web 3.0 is a term used to describe the future of the World Wide Web. Following the introduction of the phrase "Web 2.0" as a description of the recent evolution of the Web, many technologists, journalists, and industry leaders have used the term "Web 3.0" to hypothesize about a future wave of Internet innovation.

Views on the next stage of the World Wide Web’s evolution vary greatly. Some believe that emerging technologies such as the Semantic Web will transform the way the Web is used, and lead to new possibilities in artificial intelligence. Other visionaries suggest that increases in Internet connection speeds, modular web applications, or advances in computer graphics will play the key role in the evolution of the World Wide Web.

Lesson 101January 7, 2008 11:31 pm

 

Spam blogs, sometimes referred to by the neologism splogs, are artificially created weblog sites which the author uses to promote affiliated websites or to increase the search engine rankings of associated sites. The purpose of a splog can be to increase the PageRank or backlink portfolio of affiliate websites, to artificially inflate paid ad impressions from visitors, and/or use the blog as a link outlet to get new sites indexed. Spam blogs are usually a type of scraper site, where content is often either inauthentic text or merely stolen  from other websites. These blogs usually contain a high number of links to sites associated with the splog creator which are often disreputable or otherwise useless websites. Splogs are blogs where the articles are fake, and are only created for search engine spamming. (source: wikipedia)

Is your blog one of it?