Summary 

->Data Compression

A modern computer system has lakhs of files on them. Often one needs to transfer a large number of these files or an entire directory structure to another computer or storage device.Unless the user or organization has unlimited Internet plan, higher amount of data may result in higher cost as well.

Data compression generally works by identifying repetition in the data and encoding the data in a way that reduces or eliminates such repetition.

->Archive Manager

Archive Manager  permits us to combine many files or an entire directory tree into a single file known as an archive. On Linux systems, tar (tape archiver) is the most common archive format. It also provides the facility of compressing the archive to reduce its file size. It supports multiple compression algorithms and compressed file formats.

->The VLC Media Player

Ubuntu comes with built-in tools to play multimedia content like audio, video, etc. However, another great open source tool called VLC (originally it was short form of VideoLAN Client) media player .It is also extremely popular because if its versatility and features.It can convert multimedia files from one format to another. It can also stream (send) audio/video to and receive audio/video from another computer(s) over the network.

-> Google Maps

Google Mapsis a free Internet-based service provided by Google, Inc. Google has, over a period of years, collected extensive map data for the whole earth through various means like satellite imagery, cars with cameras mounted on them, data purchased from other organizations and data provided by millions of individual users around the world.

The service can be accessed from the web browser by opening the web site http://www.google.co.in and selecting the Maps option from the top menų, or directly entering the URL http://maps.google.co.in. if the GPS (Global Positioning System) facility is used. This system finds a user’s location with an estimated error of only few meters using satellite signals.

->Character Map

The Character Map program can be used to enter Unicode characters into any application. We first select the script from the left pane and then double click characters to insert them into the Text to copy area below. Spaces and punctuation may be entered from the keyboard directly into the area after clicking in it. Combining characters, like the long “II” (??????) in Gujarati can also be entered and combine with the corresponding consonant appropriately.

->The R Software

R is a free software environment for statistical computing. It is a GNU project. It is widely used for statistical analysis. It bas its own scripting language. It is a case-sensitive language. R has two work environments namely Command Line and Graphical. To use it in a GUI environment we need to install graphic editors like R Commander or RStudio from Ubuntu Software Center. The command to install R is given at the end of this chapter. To invoke the R scripts from terminal window, open terminal and type R on the command prompt.

Some common R commands include q() for quitting R, help for accessing the on line help, demo for viewing some demonstrations and help.start() to open the on line help in a browser. To get help on a particular function we need to use the syntax help(function name). When we quit R, we are asked whether we want to save the data (values of variables) from the current session.

->Plotting in R

Assume that we want to plot a bar chart that represents faculty wise students in a university. We may define the number of students as a list and the names of faculties as another list. Then we may use the function barplot with various arguments for drawing the plot.

People working in different areas like construction, engineering, services and consulting, business or software development usually work on a project that is having constraints of time, resource and budget. Any delay in completion of the project increases the cost of the project. At some point of time to manage this kind of project we need to prepare, maintain and follow a well defined plan.

It comprises three different desktop products namely RationalPlan Single, Multi and Viewer. RationalPlan Single allows us to manage independent projects that do not have common resources and bas no interrelations between different projects.

->Skype

You must have used various instant messaging services like Yahoo Messenger, Google Talk or Rediff Bol. We use them for real time chatting with text, audio and video facilities. Skype is one such software that allows us to make calls over the Internet using our computer The Skype service allows users to communicate with peers using voice, video as well as text. We can use Skype to place phone call to recipients on the traditional telephone network also.

Choose the most appropriate option from those given below :

1. Which of the following refers to a file that has an entire directory structure inside it ?
(a) apache
(b) archic
(c) archi
(d) archive

2. What is the full form of tar ?
(a) tape archiver
(b) tech archiver
(c) test archiver
(d) tight archiver

3. For which types of archives is the password protection option available ?
(a) zip
(b) tar
(c) tar.gz
(d) both zip and tar.gz

4. Which of the following is a feature-rich media player ?
(a) VAC
(b) VEC
(c) VLC
(d) VNC

5. What is the full form of VLC ?
(a) VideoLAN Client
(b) Video Line Coder
(c) Video Length Coder
(d) Video List Creater

6. Which technology gives our location with accuracy ?
(a) GRS
(b) GPRS
(c) GRPS
(d) GPS

7. Which program is used to enter Unicode characters into any application ?
(a) Character Display
(b) Character Insert
(c) Character Map
(d) Character Select

8. Which command is used to quit from R ?
(a) quit()
(b) q()
(c) exit()
(d) close()

(9) Which function is used to create a bar graph in R ?
(a) bar()
(b) plot()
(c) bargraph()
(d) barplot()

10. Which of the following are different variants of RationalPlan ?
(a) Single, Multi, Viewer
(b) Singular, Multiple
(c) View, Preview
(d) Server, Client