Wednesday, October 26, 2011

Critical Reading


Critical Reading
As far as the laws of mathematics refer to reality, they are not certain; as far they are certain, they do not refer to reality.
                                Albert Einstein

Here is an excerpt on being a critical reader. Read it carefully and see how important it is to be a critical reader.

Reading Critically
Of course, everybody knows how to read – in one sense. People read constantly – newspapers, novels, textbooks, Life, printed captions and slogans on televisions, advertising cards on buses. And in general they know what is being said. They can report to someone else the gist of a passage of writing.
But reading is much more than this. Let’s take two examples to show what we mean. First, here is a short speech. Read it once at your normal speed; then read it again, more slowly, pausing to decide just what each sentence says. What are the speaker’s ideas” what are his purposes in communicating them? How plainly and effectively does he present them? Before what sort of audience might the speech be delivered? What does the whole speech add up to?
Mr. Chairman, ladies and Gentlemen:
It is indeed a great and understands privilege to address such an audience as I see before me. At no previous time in the history of human civilization have greater problems confronted and challenged the ingenuity of men’s intelligent then now. Let us look around us. What do we see on the horizon? What forces are at work? Whither are we drifting? Under what mist of clouds does the future stand obscured?
My friends, casting aside the raiment of all human speech, the crucial test for the solution of all these intricate problems to which I have just alluded is the sheer and forceful application of those immutable laws which down the corridor of Time have always guided for his hopes and aspirations. Without these great vital principles we are but puppets responding to which and fancy, failing entirely to grasp the hidden meaning of it all. We must readdress ourselves to these questions which press for answer and solution. The issues cannot be avoided. There they stand. It is upon you, and you and yet upon me, that the yoke of responsibility falls.
What, then, is our duty? Shall we continue to drift? No! With all the emphasis of my being I hurl back the message No! Drifting must stop. We must press onward and upward toward the ultimate goal to which all must aspire.
But I cannot conclude my remarks, dear friends, without touching briefly upon a subject which I know is steeped in your very consciousness. I refer to that spirit which gleams from the eyes of a new-born babe that animates the toiling masses, that sways all the hosts of humanity past and present. Without this energizing principle all commerce, trade and industry are hushed and will perish from this earth as surely as the crimson sunset follows the golden sunshine.
Mark you, I do not seek to unduly alarm or distress the mothers, fathers, sons and daughters gathered before me in this vast assemblage, but I would indeed be recreant to a high resolve which I made as a youth if I did not at this time and in this place, and with the full realizing sense of responsibility which I assume, publicly declare and affirm my dedication and my consecration to the eternal principles and receipts of simple, ordinary, commonplace justice.
If after having carefully read and reread this speech, you haven’t got much out of it, we don’t blame you. It is a blast of hot air. The only positive point the speaker makes is that he is in favor of justice, which is not surprising, since practically everybody is in favor of justice, just as practically everybody is against sin.
But the speech as a whole isn’t about justice. In fact, it isn’t about anything. It opens with a platitude – a statement of the obvious couched in worn-out language. Then it asks a series of questions to which we might reasonably expect to get the answers before the speaker finishes. We never get them. Nor do we ever find out what is meant, by “all these intricate problems,” “those immutable laws,” “these great vital principles,” “these questions which press for answer and solution,” the issues”. “We” (who?) are said to be “drifting,” but we must keep working toward “the ultimate goal” (what?). A “spirit” is mentioned in Para 4; it is also an “energizing principle.” But again – to what does the speaker refer?
The most evident quality of the speech, looked at in this way, is that it is composed of five paragraphs of high-sounding but empty language. The unwary might jump to the conclusion that the speaker is a deep thinker, uttering immortal truths – but that is only because his words are chosen to give that impression. Actually, the speech is like a soap bubble that a child blows. It gives off pretty colors, for the moment, its words (for example, “mist of clouds”, “Faint beacon light,” “that spirit which gleams from the eyes of a new-born babe”, “the crimson sunset”, “the golden sunshine”) pleas us, just because we are accustomed to react in certain ways to such language. But when we prick the bubble with our critical intelligence, its substance proves so frail that it simply vanishes.
Look at the first sentence in para-2. Analyze it logically, word by word. If we take “casting aside the raiment of all human speech” at its face value, we have to assume that the speaker is no longer going to use “human speech”. What, we may ask, does he plan to use instead? What is meant by “the crucial test for the solution of all these intricate problems” to which he says he has “just alluded” (but he hasn’t)? What sort of picture is evoked by the hand of man groping for a beacon light?
We could say much more about this pompous speech. It is filled with trite phrases (“a great and undeserved privilege”, “the corridor of Time”, “the yoke of responsibility”, “onward and upward”, “the toiling oratorical tricks (“dear friends”, “with all the emphasis of my being I hurl back the message No!”). It uses both short sentences (Para-3) and a long one (Para-5) to produce a desired effect upon the audience…
The vital point of what we have done, however, is this. By keeping a few pertinent questions in mind a you read, you can strip away the pretensions of deliberately vague and “impressive” language and discover that, as in the case of this speech, what you are reading is a worthless as a three-dollar bill.
Having seen how critical reading can expose emptiness, if not actual deceit, let us now turn to the passive, constructive use of the same techniques. Here is part of a review of a movie. The reviewer has that the film lasted 114 minutes. Then he goes on:
A hundred and fourteen minutes is damn near two hours. You can fly from here [New York] to Cleveland in a hundred and fourteen minutes. Roger Bannister can turn twenty-eight miles in a hundred and fourteen minutes. In a hundred and fourteen minutes, you can get from here to Forest Hills on the Long Island Rail road. But a hundred and fourteen minutes of “King Richard and the Crusaders” got me exactly nowhere.
What do these five short sentences, written by a talented journalist, accomplish? It takes close, thoughtful reading to get his full massage and appreciate his true intension. He begins with the indisputable statement that 114 minutes is almost two hours. What can be done in 114 minutes? Well, you can fly from New York to Cleveland. Then our writer continues: Roger Bannister (the British athlete who was the first to run a mile in less than four minutes) can spend 114 minutes in running twenty-eight miles. At this point the alert reader does a double take: What was that last statement? A man who can run a mile in less than four minutes can run twenty-eight miles in 114 minutes. Theoretically, yes; actually, no. Bannister would have to be a superman indeed to keep up his record-breaking pace for almost two hours! The reviewer knew very well that his statement was absurd, but the absurdity, as we shall see, was part of his plan. He was suddenly switched from the demonstrably true to the obviously impossible – for a purpose. Next, he says, you can ride from New York to the suburb of Forest Hills, a distance of 8.7 miles, in 114 minutes. The full point of this probably would be appreciated by New Yorkers, for whom the review was primarily intended. The long island rail road for many years has been notorious for its slowness. Its timetable says that the running time between New York’s Penn Station and Forest Hills is sixteen minutes, but the writer, now turning cynical, implies that there is a pretty broad gap between the rail-road’s promise and its actual performance. Furthermore, by saying in effect that in 114 minutes a fast runner could fo 19.3 miles farther than a passenger could go on the Long Island Rail Road, the reviewer has capped his first absurdity (the assumption that a man ca run twenty-eight miles in 114 minutes) with a second (the assumption that he can outrace a train – even a Long Island Train).
Yes, but what has all this to do with the movie? The next sentence makes it clear: “But a hundred and fourteen minutes of ‘King Richard and the Crusader’ got me exactly nowhere. In other words, even the Long Island Rail Road, synonymous with slowness, a road whose trains (it has been humorously implied) travel less than a third as fast as a human being on two legs, moves faster than the picture does.
The reviewer could have said, in so many words, that the film drags, and let it go at that. But then he would not have had his fun, nor would his alert readers have had theirs. What he did was to begin with the idea of high speed (flying to Cleveland, running a four-minute mile) and then suddenly shift into the contrasting idea of slow motion ( the weary railroad) – the two ideas being ingeniously connected by the use of Roger Bannister. The chain of reasoning from sentence to sentence is faulty, but the fallacies were entirely intentional and the readers were expected to recognize them as such. What our critic did, therefore, was to express his essentially serious comment on a movie he didn’t like in subtly humorous terms – to entertain his readers with a bit of mental gymnastics which they could appreciate only if they read his review sentence by sentence, weighing the meaning and implication of each carefully wrought statement.
At this point you are doubtless getting alarmed. “Do you mean to say that I’ll have to read everything as closely – word by word, phrase by phrase, and sentence by sentence – as we’ve read that little quotation from a movie review?” The answer is yes – for the time being. Only by such close and admittedly time-consuming analysis can you hope to develop your critical faculty.
Critical reading involves digging beneath the surface, attempting to find out not only the whole truth about what is being said, but also (and this is, in the long run, more important) the reasons why the writer says what he goes. When a reader finds out not only what is being said, but also why it is said, he is on the way to being a critical reader as well as a comprehending one.

(Adapted from Richard D.Altick’s Preface to Critical Reading)

Friday, September 2, 2011

Ten Foods that fight disease

Certain foods fight diseases such as heart attacks, strokes and cancer. Here's how the antioxidants in fruits and vegetables improve heath and build immunity.

1. Leafy greens: A diet rich in greens such as spinach, lettuce can protect against gastric cancer, heart attack, and stroke. Leafy greens can lower your risk of cataracts and protect your eye health.
2. Tomatoes: The lycopene in tomatoes helps maintain healthy bones and regulates blood pressure. Lycopene fights disease by neutralizing free radicals, which damage normal cell growth. Tomatoes also provide cancer protection and guard against heart disease.
3. Calciferous Vegetables: Broccoli, Cabbage and Cauliflower also guard against cancer development and increase your body's detoxificaiton enzymes. These veggies help to protect against stroke and add valuable Vitamin A, folate, and calcium to your diet - and are natural ways to get healthy.
4. Berries: Blackberries, blueberries, cranberries, strawberries and rash-berries are super foods that fight disease because they're a great source of Vitamin C, fiber and antioxidants to improve your heath. Berries are a natural way to get healthy because they guard against muscular degeneration, various cancers and brain cell loss.
5. Onions and Garlic: These foods fight disease such as arthritis, heart disease, diabetes and certain cancers. Onions, Garlic and Chives are natural ways to get healthy because they are high in Vitamin C, Selenium, Potassium, and Chromium.
6. Orange Vegetables: Carrots, Sweet Potatoes, Pumpkins and Squash provide vitamin A. This Vitamin is essential for healthy growth, a strong immune system, and normal vision. Beta carotene makes these veggies orange , which is a powerful antioxidant.
7. Citrus Fruits: Grapefruit, Oranges, Tangerines and Lemons may protect against skin cancer. These foods fight disease by helping your body detoxify or get rid of toxic substances. Citrus fruits protect you from cancer and stroke, and build up you immune system.
8. Whole Grains: Foods that fight disease include whole wheat, brown rice, oatmeal and wheat berries. These foods improve health and build immunity by protecting your heart, reducing inflammation, and fighting diabetes.
9. Fish and Seafood: Salmon, Char, Haddock, Shrimp, Rainbow trout and Sardines are foods that fight disease because of their high Omega-3 fish oils. Omega 3's protect your brain, heart and blood pressure, and are associated with lower risks of various disease.
10. Legumes and Soy Foods: Black Beans, Soya beans, Split Peas and Tofu are among the 'bean and pea' foods and that fight disease. Legumes and Soya foods are low in fat and high in protein, which help ward off heart disease and prostrate cancer.

Monday, August 29, 2011

Mastering in Red Hat Linux

Mastering in Red Hat Linux
Red Hat Certified Technician
Module I: RH033 Linux Basics

Unit – 1: Introduction
Unix History
Unix was created by Dennis Ritchie and Ken Thompson in the year 1969 in AT&T Bell
Laboratories. There are various distributions of Unix such as: AIX from IBM, XENIX from
Microsoft, Solaris from Sun Microsystems, IRIX from SGI and HP-UX from HP.
Unix Principle:
• Everything is a file, including a hardware. The Unix security model is based around the
security of files.
• Configuring data stored in text. Storing configuration in text makes moving the
configuration from one machine to another very easy.
• Small single purpose program. To perform complex task, these small purpose programs can
be chained.
GNU Project/ FSP
• GNU project was started in the year 1984. Its goal was to create free UNIX clone.
• By the year 1990, almost all the user required applications were developed.
• Free Software Foundation (FSF) manages GNU project. It is non-profit making organization.
• The softwares are distributed under General Public License ( GPL)
• GNU refers to GNU is Not Unix.
Linux Origin
• A Finnish college student named Linus Trovalds created a Linux Kernel in the year 1991.
• When Linux Kernel combined with GNU applications, a complete Unix-like operating system
became possible.
Red Hat Linux
• It distributes the latest version of Linux.
• It distributes the commonly used applications with its package.
• Established in 1995 by Bob Young and Mark Ewing.
• In 1996, Red Hat 4.0 Linux was named desktop operating system of the year.
• In 1997, Red Hat 5.0 Linux was named network operating system of the year.
• In 1998, Red Hat's market share increased from 6.8% to 17.2% out of total Unix based
operating system.
• In 1999, RHCE Certification was introduced.
• In 1999, Red Hat's market share increased upto 28% out of total Unix based operating
system.
• Since 2002, RHCE Certification stands as the best professional computer based certification.
Note: The Research was conducted by Info-World magazine.
Recommended Hardware Requirements (Red Hat Linux 9)
• Pentium III or higher
• 128 Mb RAM or higher
• 5 Gb Hard Disk partition or higher
• Bootable CD-ROM
• Floppy Disk Drive.
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By Akhil Mathema
Unit – 2: Quick Tour
Run Levels
0 - halt
1 - single user
2 - multiuser
3 - multiuser
4 - unused
5 - GUI (Graphical User Interface) or X window
6 - reboot
Shutting down the system
$ halt
$ poweroff
$ init 0
$ shutdown -h now
Virtual Console
There are total 6 virtual consoles:
tty1 --> Alt+F1
tty2 --> Alt+F2
tty3 --> Alt+F3
tty4 --> Alt+F4
tty5 --> Alt+F5
tty6 --> Alt+F6
The seventh one is for the X window (GUI based) for that Ctrl+Alt+F7. And to return back to
virtual consoles from X window, user Ctrl+Alt+F1/2/3/4/5/6. X window system's terminals are
called pseudo terminals.
User Login
When logged as root (superuser) the prompt at console seems like:
[root@localhost root]#
When logged as local user the prompt at consosle seems like:
[localuser@localhost localuser]$
Adding User and assigning password
# useradd {name}
# passwd {name}
Type New-Unix Password: *******
Re-type New-Unix Password: *******
passwd: all authentication tokens updated successfully
Listing Files:
“ls” command displays files & subdirectories of the current directory.
Color code for file:
white - normal file
green - execute file
blue - directory
yellow - device file
cyan - link file
magenta - image file
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By Akhil Mathema
Creating file
$ cat > {filename}
----
Ctrl+d (to save and exit)
$ cat {filename} (to view the file)
$ mkdir {directory name} (to make directory)
$ cd {directory name} (to change directory)
Unit – 3: File and Shell Basics
Running Commands:
syntax: command [option] [argument]
• each block is separated by a space
• option modifies the behavior of command
• argument may be filename or other information needed by command
Command “pwd” is used to print the current working directory.
Command “ls” displays the contents of current or specified directory.
Syntax: ls [option] [directory]
options:
-a lists all the contents of the specified directory including hidden, current
directory(.) and parent directory(..). Files/directories whose name begin with “.” are hidden
-A is same as of -a, except it doesn't display . & ..
-l displays the long list of the contents of the directory
Command “cd” is used to change directory. While changing directory to other subdirectories, full
path name is to be given.
$ cd /directory/subdirectory
note: here the first “/” stands for the root directory like “C:/” in Ms-dos.\
$ cd ---> only enables the user to reach user's home directory.
$ cd - ---> reaches to the previous directory
$ tree ---> displays files and directories in tree structure
File names
• filenames can be up to 256 characters long
• filename that begin with “.” are known as hidden files
• special characters need special handling
Checking free space
command “df” displays the free space for the file system
# df -h (disk free in human readable form)
command “du” displays the disk usage
# du -h /var/log (to view the disk usage of /var/log directory)
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File Manipulation
command “mv” is used to move a file
syntax: mv [source filename] [destination filename]
• if the source filename and destination filename is same, the file will be renamed
• if the destination filename exists, the file will be overwritten
command “cp” is used to copy file from one location to another inside the same or different
directories.
command “touch” is used to create an empty file. But if the filename already exists, the access
time will be modified.
Command “rm” is used to delete a file
options:
-i ---> interactive mode, asks confirmation for the removal of file
-r ---> to remove a non-empty directory
-f ---> to remove file or directory forcibly without asking any confirmation
command “rmdir” is used to delete an empty directory
Running multiple commands on the same command line
syntax: first command ; second command
syntax: first command && second command
Here, “;” causes to run the second command only after the successful execution of the first
command while “&&” causes the commands to be executed sequentially independent of each
other.
Example:
$ mkdir dir1; cd dir1
Viewing text files
$ cat [option] filename
options
-s ---> squeeze [replaces the multiple blank lines by a single blank line]
-n ---> displays the line number
-A ---> displays all including control and non-printable characters like spaces, return, etc
Command “less” displays the contents of a file, one screen at a time either forward or backward.
Syntax: less {filename}
d ---> moves half screen forward
d ---> moves half screen backward
spacebar ---> moves forward by one screen
enter/return ---> moves ahead by a line
note: the above options are not command line options
options:
-s ---> squeeze [replaces the multiple blank lines by a single blank line]
-c ---> clear the screen before displaying the file
There are also other commands like “more”, “pico”, “joe”, etc to view files.
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Viewing first and last few lines of a file
Command “head” displays first few lines of a file which is 10 lines by default.
Command “tail” displays last few lines of a file which is 10 lines by default.
Example:
$ head -n 5 /etc/passwd ---> displays first 5 lines of /etc/passwd file
$ tail -f /var/log/messages ---> it is used to view constantly growing (updating) log file
File Globbing
It helps to replace the same pattern on multiple filenames. In MS-DOS it is known
as wild cards, whereas in Linux, it is known as metacharacters
? ---> matches any single character
• ---> matches any number of character
• [a-z] ---> matches into the range
• [^a-z] ---> matches all except the range
Example:
$ rm a??? ---> deletes all files of 4 characters starting with “a”
$ rm a* ---> deletes all files preceeding with “a”
$ rm [a-c] ---> deletes all files proceeding from “a” to “c”
$ rm *.* ---> deletes all files with “.” extension but not directory
Home Directory
Tild i.e. “~” represents home directory
$ ~ --->displays the path of the current user's home directory
$ dirs
~$
touch ~user/file1 ---> makes a blank file file1 on user's home directory

Saturday, July 2, 2011

Artificial Inteligent

We homo sapiens call ourselves the best creature on this beautiful planet, Just because of our mental capacities. We have tried to understand how we think; that is how a mere handful of stuff can perceive, understand, predict and manipulate a world far larger and more complicated than itself.

In today's scientific and Technological world, AI is one of the newest science. It is generally the attempt to build machines that think, as well as the study of mental facilities through the use of computational models.The research and work of AI had only started after the world war two, and the name itself was coined in 1956, along with molecular biology.

As it is the science of making machines do things that would require intelligence if done by men. It includes reasoning, learning, planning, speech recognition, vision, and language understanding. These machines are being used today in a wide variety of applications, such as monitoring credit card fraud, making autonomous decisions on space missions, watching for attacks from computer network hackers, diagnosing faults in aircraft, enabling human machine speech interfaces, and making the characters in video game behave in a more human like way.