Wednesday, December 29, 2010

INTERESTING FACTS ABOUT TECHNOLOGY

* A geostationary satellite travels at an altitude of approximately 36,000 kilometers (22,000 miles) above the Earth and at a speed of about 11,000 km ph (7,000 mph).

* Bluetooth, is named after a tenth-century king of Denmark and Norway, Harald Bluetooth. Harald was known for uniting various warring tribes in Denmark and Norway, as the technology is intended to unite various other technologies.

* A robot has already killed a human. In the summer of 1981, a Japanese industrial robot malfunctioned. Its repairman neglected to open the chain fence around the robot that would have shut off the robot’s power, and then accidentally touched the switch that turned the robot on. The robot then performed the actions that it was designed to do, and with the human in the way the robot caught the employee, pinning him against a machine processing automobile gears, killing him.

* The advent of the photo-finish camera took the guesswork out of judging horse races. It showed that human judges were generally accurate, but not on the close calls. In pre-camera 1935, judges called only 20 dead heats, but in 1938, when most tracks had cameras, films showed 264 dead heats.

* The first patent for a fax machine was issued to British clockmaker Alexander Bain in 1843, over 30 years before the telephone. In 1865, Abbé Caselli introduced the first commercial facsimile system, between Paris and Lyons. Newspapers began to send photographs starting in 1902.Modern fax machines were developed by the Japanese due to difficulties in otherwise transmitting their written language.

* Primitive batteries capable of producing ½ volt of electricity were made in Mesopotamia between around 200 B.C. and 200 A.D. They were used mainly for electroplating silver onto copper.

*Printer manufacturers print invisible yellow dots on consumer’s prints that check to see if a person is printing counterfeit money. If you call your printer manufacturer and ask them to “please stop spying on you”, they will send secret services to your address to find out why you care about your privacy.

Thursday, December 23, 2010

LINUX COMMANDS (4)

Hosts 

uname -Print system information
hostname -Print the system’s hostname
ifconfig -Set/display network information
host -Look up DNS
whois -Look up domain registrants
ping -Check if host is reachable
traceroute -View network path to a host

Networking 


ssh -Securely log into remote hosts
telnet- Log into remote hosts
scp -Securely copy files between hosts
sftp -Securely copy files between hosts
ftp -Copy files between hosts
evolution- GUI email client
mutt- Text-based email client
mail -Minimal email client
mozilla -Web browser
lynx -Text-only web browser
wget -Retrieve web pages to disk
slrn- Read Usenet news
gaim- Instant messaging/IRC
talk -Linux/Unix chat
write -Send messages to a terminal
mesg -Prohibit talk/write

Audio and Video 

grip -Play CDs and rip MP3s
xmms -Play audio files
cdparanoia -Rip audio
audacity -Edit audio
xcdroast -Burn CDs

Tuesday, December 21, 2010

LINUX COMMANDS (3)

Printing 

lpr -Print files
lpq -View print queue
lprm -Remove print jobs

Spelling Operations 

look -Look up spelling
aspell -Check spelling interactively
spell -Check spelling in batch

Processes 

ps -List all processes
w -List users’ processes
uptime- View the system load
top -Monitor processes
xload -Monitor system load
free -Display free memory
kill -Terminate processes
nice -Set process priorities
renice- Change process priorities

Scheduling Jobs 

sleep -Wait for some time
watch- Run programs at set intervals
at -Schedule a job
crontab -Schedule repeated jobs

Monday, December 20, 2010

AVIATION

Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft.

AIR TRANSPORT
Main article: Airline


There are five major manufacturers of civil transport aircraft :

* Airbus, based in Europe
* Boeing, based in the United States
* Bombardier, based in Canada
* Embraer, based in Brazil
* United Aircraft Corporation, based in Russia

TYPES OF MILITARY AVIATION

* Fighter aircraft's primary function is to destroy other aircraft. (e.g. Sopwith Camel, A6M Zero, F-15, MiG-29, Su-27, F-22).
* Ground attack aircraft are used against tactical earth-bound targets. (e.g. Junkers Stuka dive bomber, A-10 Warthog, Ilyushin Il-2, J-22 Orao, and Sukhoi Su-25).
* Bombers are generally used against more strategic targets, such as factories and oil fields. (e.g. Zeppelin, B-29 Superfortress, Tu-95, Dassault Mirage IV, and the B-52 Stratofortress)
* Cargo transport aircraft are used to transport hardware and personnel, such as the C-17 Globemaster III or C-130 Hercules.
* Projectile is used for goods only, normally explosives, but also things like leaflets
* Surveillance aircraft are used for reconnaissance (e.g. Rumpler Taube, de Havilland Mosquito, U-2, and MiG-25R).
* Helicopters are used for assault support, cargo transport and close air support (e.g.AH-64, Mi-24).

LINUX COMMANDS (2)

File Location 


  • find - Locate files 
  • slocate - Locate files via index 
  • which - Locate commands 
  • whereis - Locate standard files 


File Text Manipulation 


  • grep - Search text for matching lines 
  • cut- Extract columns 
  • paste - Append columns 
  • tr - Translate characters 
  • sort - Sort lines 
  • uniq- Locate identical lines 
  • tee- Copy stdin to a file and to stdout simultaneously 


File Compression 


  • gzip - Compress files (GNU Zip) 
  • compress - Compress files (Unix) 
  • bzip2 - Compress files (BZip2) 
  • zip - Compress files (Windows Zip) 


File Comparison 


  • diff - Compare files line by line 
  • comm.- Compare sorted files 
  • cmp - Compare files byte by byte 
  • md5sum - Compute checksums 



Disks and File systems 


  • df - Show free disk space 
  • mount - Make a disk accessible 
  • fsck - Check a disk for errors 
  • sync - Flush disk caches 


Backups and Remote Storage 


  • mt - Control a tape drive 
  • dump - Back up a disk 
  • restore - Restore a dump 
  • tar - Read/write tape archives 
  • cdrecord - Burn a CD 
  • rsync - Mirror a set of files 


PHP (HYPERTEXT PREPROCESSING)

- Used to Create dynamic and User friendly websites.
- Used to write a server side scripting.
- Scripts executed in webservers like Apache, Tomcat, IIS (Internet Information Service), etc.
- Support many databases, mainly MySQL.
- Opensource Software.
Extensions of PHP file:
* .php
* .php3
* .phtml
Why PHP:
Ø Runs in any Platform.
Ø Compatible with almost all servers used today.
Ø PHP is easy to learn and runs efficiently on sever side.
Commands used in PHP:
* print – Print in screen.
* Echo – Print in screen.
* hr (Inside <>) - Breaking lines with a horizontal line (Ruler).
* br (Inside <>) - Break Line.
* // - Making a line not to work.
* /* */ - Making multiple lines not to work.
Variables in PHP:
ü No quotes for numerical values.
ü Quotes for Characters.
Eg:

Sunday, December 19, 2010

Noble Prize - 2010

Noble prize for the year 2010:

*Nobel Prize in Economics 2010 shares 3 persons

They are (1) Peter A. Diamond (2) Dale T. Mortensen and (3) Christopher A. Pissarides for creating mathematical models which provide the framework for studying how such processes occur in the real world.

*Nobel Peace Prize for 2010 to Liu Xiaobo

The Nobel Committee has decided to award the Nobel Peace Prize for 2010 to Liu Xiaobo for his long and non-violent struggle for fundamental human rights in China.

*The Nobel Prize in Literature 2010-Mario Vargas Llosa

The Nobel Prize in Literature 2010 was awarded to Mario Vargas Llosa “for his cartography of structures of power and his trenchant images of the individual’s resistance, revolt, and defeat”.

*The Nobel Prize Winners in Chemistry 2010- Richard Heck, Ei-ichi Negishi and Akira Suzuki

Richard Heck, Ei-ichi Negishi and Akira Suzuki were cited for their work in “palladium-catalyzed cross couplings in organic synthesis.” That’s a way of joining together carbon atoms — using the element palladium as a catalyst — in a more efficient and precise way than was previously done. And joining together carbon atoms helps scientists do a lot of nifty things, including making medicines.

*Nobel Prize 2010 in physics goes to Russian born scientists

Russian-born scientists Andre Geim and Konstantin Novoselov shared the Nobel Prize in physics on Tuesday for “groundbreaking experiments” with an atom-thin material expected to play a large role in electronics.

*Robert Edwards-The Father of IVF Medicine Named As Nobel Prize Winner 2010

Robert Edwards, the British scientist who first founded the in-vitro fertilization (IVF) technique as a means of conceiving a child to parents who failed to do so conservatively worldwide, has been awarded as the Nobel Prize winner for Physiology/Medicine contribution category this year by the Nobel Assembly.

Friday, December 17, 2010

Medical procedures and test

Thyroid Blood Tests:
Blood tests used to determine the adequacy of the levels of thyroid hormones.

CAT Scan:
A procedure that produces images of structures within the body created by a computer that takes data from multiple X-ray images and turns them in pictures on a screen.

Chemotherapy:
This treatment—which can be given intravenously (through a vein), by mouth, through an injection (shot), or applied on the skin—destroys cancer cells.

Colonoscopy:
Procedure using a viewing tube that enables an examiner (usually a gastroenterologist) to evaluate the appearance of the inside of the colon (large bowel).

LINUX COMMANDS (1)

File/Directory Basics

ls - List files
cp - Copy files
mv - Rename files
rm - Delete files
ln - Link files
cd - Change directory
pwd - Print current directory name
mkdir - Create directory
rmdir - Delete directory

File Viewing

cat - View files
less - Page through files
head - View file beginning
tail - View file ending
nl - Number lines
od - View binary data
xxd - View binary data
gv - View Postscript/PDF files
xdvi - View TeX DVI files

File Creation and Editing

emacs - Text editor
vim - Text editor
umask - Set default file protections
soffice - Edit Word/Excel/ PowerPoint docs
abiword - Edit Word documents
gnumeric - Edit Excel documents

File Properties

stat - Display file attributes
wc - Count bytes/words/lines
du - Measure disk usage
file - Identify file types
touch - Change file timestamps
chown - Change file owner
chgrp - Change file group
chmod - Change file protections
chattr – Change advanced file attributes
lsattr - List advanced file attributes 

Thursday, December 16, 2010

Types of Linux

Linux

·         Linux is PC-UNIX in which the kernel was created for PC/AT compatibles by Linus Torvalds of Finland.
·         The name is derived from the kernel's creator.
·         The kernel is the essential center of a computer operating system, the core that provides basic services for all other parts of the operating system. 

Distribution

·         Although Linux is originally the kernel created by Linus, it does not function as an OS generally available with only the kernel.
·         To function as an OS, various software applications must be combined with the kernel.
·         Thus, the combination of the kernel and some application software supporting it for use as an OS is called a "distribution".

Types of distribution

·         A number of application software programs as well as the kernel is needed to run as an OS, but software applications necessary depend on the specific purpose of use or policy.
·         This is the difference of distributions, so there are many distributions.
·         The biggest difference is the management method of a package (software) shown as follows:

RedHat series

 The package management is by rpm. It is easy to install, upgrade and so on.
 The main distributions are the following:
·         RedHat Linux
·         Turbo Linux
·         LASER5 Linux
·         Kondara MNU/Linux
·         Vine Linux
 There are more distributions than other series of Linux.

Slackware series

Since it has no management tool, users manage all. It requires considerable knowledge, but it has a high degree of flexibility, so it is popular among the users understanding the system.
 The main distributions are the following:
·         Slackware
·         Plamo Linux
Debian series
 
The package management is by deb. It is more powerful than that by rpm and closely manages even the dependency relation among the software.
 The main distribution is the following:
·         Debian GNU/Linux

How to select a distribution

To select a distribution, you have to understand the purpose of use or the policy at which the distribution aims at. Here, I will show you the differences of the distributions I found after using them.

RedHat Linux

Practically all of the Linux of RedHat series are based on this distribution, so the introduction of a new kernel is earlier than in other distributions.
However, it might have more trouble in the first version (version *.0) than other distributions of the RedHat series.
 For neophilia, I recommend version *.1 or later.

Turbo Linux

It is moderately good for use in companies. There are various types, such as for servers in Turbo Linux.

LASER5 Linux

This distribution allows for the easy use of Japanese, developed on the basis of RedHat Linux. (Note that RedHat can be used in Japanese as well.) .
Most of the software for RedHat Linux can be used.

Kondara MNU/Linux

Based on RedHat Linux, this distribution has introduced new useful software. Therefore, it has different parts from other distributions of RedHat series.
For anyone liking novelties.

Vine Linux

A Distribution with emphasis on the stability and enhancement of Japanese environments, Based on RedHat Linux. There are fewer version upgrades than other distributions of RedHat series.
For anyone wanting to use Japanese in plenty.

Slackware

The oldest distribution of Linux. Considerable knowledge is required for package management. It is also necessary to personally set up the Japanese environment.
For professionals or anyone wanting to understand the system "with a will".

Plamo Linux

Distribution which supports Japanese, based on Slackware. Although it supports Japanese, considerable knowledge is required, as in the case of Slackware.

Debian GNU/Linux

Distribution with enhanced package management. It was developed mainly by users.
For anyone wanting to engage in the development of distribution (I suppose).

Tuesday, December 14, 2010

BASIC COMMANDS IN LINUX

1.ls -l for listing the files as well as directories those are kept in
the particular working directory
syntax
[root@nettech root]#ls -l

2.ls -la same as 'ls -l'but by this command we can also see the hiden
files.
syntax
[root@nettech root]#ls -la

3.ls -li same as 'ls -la' but it will also shows us the inode number of
each and every file
syntax
[root@nettech root]#ls -li

4.ls by this command we can see only file name nothing else
syntax
[root@nettech root]#ls

5.clear it will clear the screen(short cut ctl+l)
syntax
[root@nettech root]#clear

6.exit to end a current session as well current terminal logging
syntax
[root@nettech root]exit

7.touch to create a new empty file
syntax
[root@nettech root]#touch

8.cd to change the working/present directory
syntax
[root@nettech root]#cd /home/mango
where '/home/mango' is the desired directory to be change from
'/root'

9.cat to view the contents of a file and it is also used for creating a
new file with some contents
syntax
[root@nettech root]#cat to view file contents
[root@nettech root]#cat > newfilename enter,then you can write something in
the file and then to save the file contents press clt+d then enter

10.mkdir to make a new directory
syntax
[root@nettech root]#mkdir newdirname
you can also create a directory at your desired path without
changing your present working directory
syntax
[root@nettech root]#mkdir /home/mango/newdirname

11.rm to remove a empty file
syntax
[root@nettech root]#rm filename

12.rmdir to remove a empty directory
syntax
[root@nettech root]#rmdir directoryname

13.rm [-i/-r/-f] to remove a directory with its subdirectories as well as its
files that is to remove a directory which already contains some files in it
syntax
[root@nettech root]#rm -i directory/filename
-i stands for interactively
-r stands for recursively
-f stands for forcefully

14.cp to copy something in a destination file or directory
syntax
[root@nettech root]#cp sourcepath destinationpath
example: [root@nettech root]#cp /home/mango/webmin.rpm /root/abcd
in this example the webmin.rpm file will be copied in
/root/abcd directory

15.mv to move one file or directory from one place to another place, it
is also used for renaming adirectory or file
syntax
[root@nettech root]#mv source destination
[root@nettech root]#mv oldfilename newfilename [to change the file name]

16.man to view the mannual page of commands for syntax
syntax
[root@nettech root]#man commandname

17.info to view the information about any command
syntax
[root@nettech root]#mkdir info

18.--help to view the help doccuments of a command
syntax
[root@nettech root]#commandname --help

19.dir to view the subdirectories and filesn under the directory
syntax
[root@nettech root]#dir

20.su - to become a super user
syntax
[mango@nettech mango]$su -
output wil be
[root@nettech root#]

21.who by this command you can see the user name and their ip addresses
who have loged in on your server
syntax
[root@nettech root]#who

22.whoami this command shows your current logged in terminal user name
syntax
[root@nettech root]#whoami

23.who am i this command shows you the logged in terminal number and user
name and more detailed information
syntax
[root@nettech root]#who am i

24.pwd to view the present working directory
syntax
[root@nettech root]#pwd

25.rpm -ivh to intall a rpm package
syntax
[root@nettech root]#rpm -ivh packagename.rpm
rpm stands for 'redhat package manager'
-i stands for install
-v stands for verbose mode
-h stands for with hash sign(#)

Monday, December 13, 2010

How To Install Linux

How To Install Linux

System Requirements:

Operating Systems

Processors

Disk Space

RAM

32-Bit and 64-Bit MATLAB and Simulink Product Families

Supported distributions*:

Ubuntu 9.10 and 10.04 LTS

Red Hat Enterprise Linux 5.x

SUSE Linux Enterprise Desktop 11.x

Debian 5.x

Any Intel or AMD x86 processor supporting SSE2 instruction set**

1 GB for MATLAB only,
3–4 GB for a typical installation

1024 MB
(At least 2048 MB recommended)

v Choose A PC For Linux

Ø Preinstalled PC’s. HP, IBM, and Dell are increasingly supporting Linux.

Ø Recycle an older PC.

v Prepare The System

Ø Back up your data.

Ø Record your network configuration information. (IP Address, DNS, DHCP)

Ø Check the cables.

Ø Make sure your PC can boot from a CD.

v Start The Installation

Ø Insert the distribution's first installation CD or DVD.

Ø Select the Installation option.

Ø Choose a language for the installation.

v Installation Choices

Ø System. This will display system data about the CPU, drives, network, video and sound cards, and other peripherals. You can view or write the data to a file.

Ø Installation mode. When an OS is already installed on a system, this option will let you do a new installation over an existing Linux OS, update or repair an existing Linux installation, or boot the PC from the existing OS.

Ø Keyboard layout. If you want to fine-tune the keyboard defaults, choose this option and use the Expert Settings option at the bottom of the keyboard setup screen. This lets you disable the CAPS LOCK key, turn the CAPS LOCK/NUM LOCK keys on or off at boot-up, and more.

Ø Mouse. The installer will probably detect and configure your mouse properly, but you may want to choose your mouse with this option and test it to make sure.

Ø Partitioning. This option lets you determine how your hard drive space is allocated and used.

Ø Software. The option lets you determine which software you want to install.

Ø Booting. This lets you determine how your system will boot, with such options available as booting to Windows or another OS when the system starts up.

Ø Time zone. This option lets you select the appropriate time zone for your situation. The default is Pacific Time.

Ø Language. The default language for this distribution is English, American, but you can change it to a language that's appropriate for your situation.

Ø Default runlevel. Runlevel specifies how Linux will operate. Options include running the system as a single- or multiuser machine, as a networked machine, and using a GUI (graphical user interface) Windows manager or not. The default is 5, which sets the system to run as a networked multiuser system with a graphical login.

v Partitioning

v Choose Software

v Configure

Ø After the software is copied, the installer will proceed to the system-configuration steps, which include the following

§ Enter a root password.

§ Configure the network.

§ Test the Internet connection.

§ Determine a user authentication method.

§ Add a new local user.

§ Read the release notes.

§ Configure the hardware.

§ The installation is now complete.

v Reboot the system, but don't forget to remove the last install CD.