24 August 2011
Interesting Unknown facts in Technology - Rajasekaran S II IT 'B'
INTERESTING UNKNOWN FACTS IN TECHNOLOGY
Ø Coca-Cola was originally green.
Ø The most common name in the world is Mohammed.
Ø The names of all the continents end with the same letter that they start with.
Ø The strongest muscle in the body is the tongue.
Ø There are two credit cards for every person in the United States.
Ø TYPEWRITER is the longest word that can be made using the letters only on one row of the keyboard.
Ø Women blink nearly twice as much as men!
Ø You can't kill yourself by holding your breath.
Ø It is impossible to lick your elbow.
Ø People say "Bless you" when you sneeze because when you sneeze, your heart stops for a millisecond.
Ø It is physically impossible for pigs to look up into the sky
Ø The "sixth sick sheik's sixth sheep's sick" is said to be the toughest tongue twister in the English language.
Ø If you sneeze too hard, you can fracture a rib. If you try to suppress a sneeze, you can rupture a blood vessel in your head or neck and die.
Ø Each king in a deck of playing cards represents great king from history.
Spades - King David
Clubs - Alexander the Great,
Hearts - Charlemagne
Diamonds - Julius Caesar.
Ø 111,111,111 x 111,111,111 = 12,345,678,987,654,321
Ø If a statue of a person in the park on a horse has both front legs in the air, the person died in battle.
If the horse has one front leg in the air, the person died as a result of wounds received in battle.
If the horse has a all four legs on the ground, the person died of natural causes.
Ø What do bullet proof vests, fire escapes, windshield wipers and laser printers all have in common?
Ans. - All invented by women.
Ø Question - This is the only food that doesn't spoil. What is this?
Ans. - Honey
Ø A crocodile cannot stick its tongue out.
Ø A snail can sleep for three years.
Ø All polar bears are left handed.
Ø American Airlines saved $40,000 in 1987 by eliminating one olive from each salad served in first-class.
Ø Butterflies taste with their feet.
Ø Elephants are the only animals that can't jump.
Ø In the last 4000 years, no new animals have been domesticated.
Ø On average, people fear spiders more than they do death.
Ø Shakespeare invented the word 'assassination' and 'bump'.
Ø Stewardesses is the longest word typed with only the left hand.
Ø The ant always falls over on its right side when intoxicated.
Ø The electric chair was invented by a dentist.
Ø The human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.
Ø Rats multiply so quickly that in 18 months, two rats could have over million descendants.
Ø Wearing headphones for just an hour will increase the bacteria in your ear by 700 times
Ø The cigarette lighter was invented before the match.
Ø Most lipstick contains fish scales.
Ø Like fingerprints, everyone's tongue print is different.
Ø On average, 12 newborns will be given to the wrong parents daily! That explains it!
Ø Donald Duck comics were banned from Finland because he doesn't wear pants.
Ø Because metal was scarce, the Oscars given out during World War II were made of wood.
Ø The number of possible ways of playing the first four moves per side in a game of chess is 318,979,564,000.
Ø There are no words in the dictionary that rhyme with orange, purple and silver.
Ø The very first bomb dropped by the Allies on Berlin in World War II killed the only elephant in the Berlin Zoo.
Ø If one places a tiny amount of liquor on a scorpion, it will instantly go mad and sting itself to death.
Ø Bruce Lee was so fast that they actually had to s-l-o-w film down so you could see his moves.
Ø The original name for butterfly was flutterby.
Ø By raising your legs slowly and laying on your back, you cannot sink into quicksand.
Ø Charlie Chaplin once won third prize in a Charlie Chaplin look-alike contest.
Ø Chewing gum while peeling onions will keep you from crying.
Ø The Guinness Book of Records holds the record for being the book most often stolen from Public Libraries.
Ø Astronauts are not allowed to eat beans before they go into space because passing wind in a spacesuit damages them. Not to mention the other drawback.
Ø Bats always turn left when exiting a cave.
Ø When the moon is directly overhead, you will weigh slightly less.
Ø Alexander Graham Bell, the inventor of the telephone, never called his wife or mother because they were both deaf.
Ø An ostrich's eye is bigger than its brain.
Ø "I Am" is the shortest complete sentence in the English language.
Ø Babies are born without knee caps – actually, they're made of cartilage and the bone hardens between the ages of 2 and 6 years.
Ø Happy Birthday (the song) is copyrighted.
Ø Butterflies taste with their feet.
Ø Elephants are the only animals that cannot jump.
Ø The shortest war in history was between Zanzibar and England in 1896. Zanzibar surrendered after 38 minutes.
Ø Camels have three eyelids to protect themselves from the blowing desert sand.
Ø Money isn't made out of paper. It's made out of cotton.
Ø Your stomach has to produce a new layer of mucus every two weeks or it will digest itself.
Ø Chocolate can kill dogs, as it contains theobromine, which affects their heart and nervous system.
Ø There are only two words in the English language that have all five vowels in order: "abstemious" and "facetious."
Ø The shortest English word that contains the letters A, B, C, D, E, and F is "feedback."
Ø Almonds are a member of the peach family, and apples belong to the rose family.
Ø Peanuts are one of the ingredients of dynamite.
Ø Tigers have striped skin, not just striped fur.
Ø The planet Venus does not tilt, so consequently, it has no seasons. It is the only planet that rotates clock-wise.
Ø Molecularly speaking, water is actually much drier than sand.
Ø Human tonsils can bounce higher than a rubber ball of similar weight and size, but only for the first 30 minutes after they've been removed.
Ø Moths are unable to fly during an earthquake.
Ø Contrary to popular belief, the white is not the healthiest part of an egg. It's actually the shell.
Ø Nearly three percent of the ice in Antarctic glaciers is penguin urine.
Ø Hot water will turn into ice faster then cold water.
Ø Pumice is the only rock that floats in water.
Ø Camel's milk does not curdle.
Ø Your foot is the same length as your forearm, and your thumb is the same length as your nose. Also, the length of your lips is the same as the index finger.
Ø Natural pearls melt in vinegar.
Ø Buttermilk does not contain any butter.
Ø The human brain is 80% water.
Ø Men's shirts have the buttons on the right while women's shirts have the buttons on the left.
Ø Human fingernails grow nearly 4 times faster than toenails.
Ø The Great Pyramid at Giza in Egypt holds a constant temperature of 68 degrees Fahrenheit.
Ø The liquid inside young coconuts can be used as a substitute for blood plasma.
Ø Oak trees do not produce acorns until they are fifty years of age.
Ø It takes approximately 2 million flowers for a bee to make 1 pound of honey.
Ø Human saliva has a boiling point three times that of regular water.
Ø It is physically impossible to urinate and give blood at the same time.
Ø The letter J does not appear anywhere in the periodic table of the elements.
Ø The right lung of a human is larger than the left one. This is because of the space and placement of the heart.
Ø Watermelons, which are 92% water, originated from the Kalahari Desert in Africa.
Ø The hair of some cancer patients treated with chemotherapy can grow back in a different colour, and sometimes even be curly or straight.
Ø Dolphins can swim and sleep at the same time, as they sleep with one eye open.
Ø Each nostril of a human being registers smell in a different way. Those by the right nostril are more pleasant than the left.
CRYPTOGRAPHY AND ITS RECENT TRENDS - Lavanya K III IT 'A'
CRYPTOGRAPHY AND ITS RECENT TRENDS
1. INTRODUCTION
The Internet or the global Internet is the internationally connected network of computer networks with addresses that are administrated by IANA (Internet address and Naming Authority). It grew dramatically because anyone can connect to it and anyone connected to it can connect others to it as well. Each site that connected to it, can become an Internet Service provider to other sites Does increased security provide comfort to paranoid people? Or does security provide some very basic protections that we are naive to believe that we don't need? During this time when the Internet provides essential communication between tens of millions of people and is being increasingly used as a tool for commerce, security becomes a tremendously important issue to deal with. There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography. This paper has two major purposes. The first is to define some of the terms and concepts behind basic cryptographic methods, and to offer a way to compare the myriad cryptographic schemes in use today. The second is to provide some real examples of cryptography and new trends in use today. I would like to say at the outset that this paper is very focused on terms, concepts, and schemes in current use and is not a treatise of the whole field.
2. THE PURPOSE OF CRYPTOGRAPHY
Cryptography is the science of writing in secret code and is an ancient art;
there are some specific security requirements, including:
Authentication: The process of proving one's identity.
Privacy/confidentiality: Ensuring that no one can read the message except the intended receiver.
Integrity: Assuring the receiver that the received message has not been altered in any way from the original.
Non-repudiation: A mechanism to prove that the sender really sent this message.
Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication. There are, in general, three types of cryptographic schemes typically used to accomplish these goals: secret key (or symmetric) cryptography, public-key (or asymmetric) cryptography, and hash functions, each of which is described below. In all cases, the initial unencrypted data is referred to as plaintext. It is encrypted into cipher text, which will in turn (usually) be decrypted into usable plaintext.
3. TYPES OF CRYPTOGRAPHIC ALGORITHMS
There are several ways of classifying cryptographic algorithms.
Secret Key Cryptography (SKC): Uses a single key for both encryption and decryption.
Public Key Cryptography (PKC): Uses one key for encryption and another for decryption.
Hash Functions: Uses a mathematical transformation to irreversibly "encrypt" information.
First is a crypto algorithm, which specifies the mathematical transform action that is performed on data to encrypt (or) decrypt it. Crypto algorithm is a procedure that takes the plain text data and transforms it into cipher text in a reversible way.
4. NEW TREND IN CRYPTOGRAPHY
Elliptic Curve Cryptography
In general, public-key cryptography systems uses hard-to-solve problems as the basis of the algorithm. The most predominant algorithm today for public-key cryptography is RSA, based on the prime factors of very large integers. While RSA can be successfully attacked, the mathematics of the algorithm has not been comprised, per se; instead, computational brute-force has broken the keys. The defense is "simple" keep the size of the integer to be factored ahead of the computational curve! In 1985, Elliptic Curve Cryptography (ECC) was proposed independently by cryptographers Victor Miller (IBM) and Koblitz (University of Washington). ECC is based on the difficulty of solving the Elliptic Curve Discrete Logarithm Problem (ECDLP). Like the prime factorization problem, ECDLP is another "hard" problem that is deceptively simple to state: Given two points, P and Q, on an elliptic curve, find the integer n, if it exists, such that p= nQ. Elliptic curves combine number theory and algebraic geometry. These curves can be defined over any field of numbers (i.e., real, integer, complex) although we generally see them used over finite fields for applications in cryptography. An elliptic curve consists of the set of real numbers (x, y) that satisfies the equation:y2 = x3 + ax + b. An attacker might know P and Q but finding the integer, n, is a difficult problem to solve. Q is the public key, then, and n is the private key.
5. CONCLUSION
We use different types of algorithms to establish security services in different service mechanisms. We use either private key cryptography or public key cryptography according to requirement. If we want to send message quickly we use private key algorithm and if we want to send messages secretly we use public key algorithm. Hence let us hope that the NEW TRENDS of cryptography saves the messages from the DANGEROUS CLUTCHES OF MESSAGE HACKERS.
History of Quantum Computing - Sukanya A III IT 'B'
HISTORY OF QUANTUM COMPUTING
In the classical model of a computer, the most fundamental building block, the bit, can only exist in one of two distinct states, a 0 or a 1. In a quantum computer the rules are changed. Not only can a 'quantum bit', usually referred to as a 'qubit', exist in the classical 0 and 1 states, it can also be in a coherent superposition of both. When a qubit is in this state it can be thought of as existing in two universes, as a 0 in one universe and as a 1 in the other. An operation on such a qubit effectively acts on both values at the same time. The significant point being that by performing the single operation on the qubit, we have performed the operation on two different values. Likewise, a two-qubit system would perform the operation on 4 values, and a three-qubit system on eight. Increasing the number of qubits therefore exponentially increases the 'quantum parallelism' we can obtain with the system. With the correct type of algorithm it is possible to use this parallelism to solve certain problems in a fraction of the time taken by a classical computer.
A number of key advances have been made in the theory of quantum computation, the first being the discovery that a simple class of 'universal simulator' can mimic the behavior of any finite physical object, by Richard Feynman in 1982. David Albert made the second discovery in 1984 when he described a 'self measuring quantum automaton' that could perform tasks that no classical computer can simulate. By instructing the automaton to measure itself, it can obtain 'subjective' information that is absolutely inaccessible by measurement from the outside. The final and perhaps most important discovery was made by David Deutsch in 1989, he proved that all the computational capabilities of any finite machine obeying the laws of quantum computation are contained in a single machine, a 'universal quantum computer'. Such a computer could be built from the quantum equivalent of the Toffoli gate and by adding a few extra operations that can bring about linear superpositions of 0 and 1 states; the universal quantum computer is complete. This discovery requires a slight alteration to the Church-Turing principle - "There exists or can be built a universal quantum computer that can be programmed to perform any computational task that can be performed by any physical object".
Building a quantum computer
A quantum computer is nothing like a classical computer in design; you can't for instance build one from transistors and diodes. In order to build one, a new type of technology is needed, a technology that enables 'qubits' to exist as coherent super positions of 0 and 1 states. The best method of achieving this goal is still unknown, but many methods are being experimented with and are proving to have varying degrees of success.
Quantum dots
An example of an implementation of the qubit is the 'quantum dot' which is basically a single electron trapped inside a cage of atoms. When the dot is exposed to a pulse of laser light of precisely the right wavelength and duration, the electron is raised to an excited state: a second burst of laser light causes the electron to fall back to its ground state. The ground and excited states of the electron can be thought of as the 0 and 1 states of the qubit and the application of the laser light can be regarded as a controlled NOT function as it knocks the qubit from 0 to 1 or from ' to 0.
If the pulse of laser light is only half the duration of that required for the NOT function, the electron is placed in a superposition of both ground and excited states simultaneously, this being the equivalent of the coherent state of the qubit. More complex logic functions can be modeled using quantum dots arranged in pairs. It would therefore seem that quantum dots are a suitable candidate for building a quantum computer. Unfortunately there are a number of practical problems that are preventing this from happening:
* The electron only remains in its excited state for about a microsecond before it falls to the ground state. Bearing in mind that the required duration of each laser pulse is around 1 nanosecond, there is a limit to the number of computational steps that can be made before information is lost.
* Constructing quantum dots is a very difficult process because they are so small. A typical quantum dot measures just 10 atoms (1 nanometer) across. The technology needed to build a computer from these dots doesn't yet exist.
* To avoid cramming thousands of lasers into a tiny space, quantum dots could be manufactured so that they respond to different frequencies of light. A laser that could reliably retune itself would thus selectively target different groups of quantum dots with different frequencies of light. This again, is another technology that doesn't yet exist.
Computing liquids
Quantum dots are not the only implementation of qubits that have been experimented with. Other techniques have attempted to use individual atoms or the polarization of laser light as the information medium. The common problem with these techniques is decoherence. Attempts at shielding the experiments from their surroundings, by for instance cooling them to within a thousandth of a degree of absolute zero, have proven to have had limited success at reducing the effects of this problem.
The latest development in quantum computing takes a radical new approach. It drops the assumption that the quantum medium has to be tiny and isolated from its surroundings and instead uses a sea of molecules to store the information. When held in a magnetic field, each nucleus within a molecule spins in a certain direction, which can be used to describe its state; spinning upwards can signify a 1 and spinning down, a 0. Nuclear Magnetic Resonance (NMR) techniques can be used to detect these spin states and bursts of specific radio waves can flip the nuclei from spinning up (1) to spinning down (0) and vice-versa.
The quantum computer in this technique is the molecule itself and its qubits are the nuclei within the molecule. This technique does not however use a single molecule to perform the computations; it instead uses a whole 'mug' of liquid molecules. The advantage of this is that even though the molecules of the liquid bump into one another, the spin states of the nuclei within each molecule remain unchanged. Decoherence is still a problem, but the time before the decoherence sets in is much longer than in any other technique so far. Researchers believe a few thousand primitive logic operations should be possible within time it takes the qubits to deco here.
Dr. Gershenfield from the Massachusetts Institute of Technology is one of the pioneers of the computing liquid technique. His research team has already been able to add one and one together, a simple task which is way beyond any of the other techniques being investigated. The key to being able to perform more complex tasks is to have more qubits but this requires more complex molecules with a greater number of nuclei, the caffeine molecule being a possible candidate. Whatever the molecule, the advancement to 10 qubit systems is apparently straightforward. Such a system, Dr. Gershenfield hopes, will be possible by the end of this year, and should be capable of factoring the number 15.
Advancing beyond a 10-qubit system may prove to be more difficult. In a given sample of 'computing liquid' there will be a roughly even number of up and down spin states but a small excess of spin in one direction will exist. It is the signal from this small amount of extra spin, behaving as if it were a single molecule that can be detected and manipulated to perform calculations while the rest of the spins will effectively cancel each other out. This signal is extremely weak and grows weaker by a factor of roughly 2 for every qubit that is added. This imposes a limit on the number of qubits a system may have as the readable output will be harder to detect.
Microsoft Tablet PC - Rakini M II IT 'B'
MICROSOFT TABLET PC
A Microsoft Tablet PC is a term coined by Microsoft for tablet computers conforming to a set of specifications announced in 2001 by Microsoft, for a pen-enabled personal computer, conforming to hardware specifications devised by Microsoft and running a licensed copy of Windows XP Tablet PC Edition operating system or a derivative thereof.
Hundreds of such tablet personal computers have come onto the market since then.
History
In 2002, original equipment manufacturers' released the first tablet PCs designed to the Microsoft Tablet PC specification. This generation of Microsoft Tablet PCs were designed to run Windows XP Tablet PC Edition, the Tablet PC version of Windows XP. This version of Microsoft Windows superseded Microsoft's earlier operating environment, Windows for Pen Computing 2.0. After releasing Windows XP Tablet PC Edition, Microsoft designed the successive desktop computer versions of Windows, Windows Vista and Windows 7, to support pen computing intrinsically.
Form variations of Tablet PCs
Booklets
Booklet PCs are dual screen tablet computers that fold like a book. Typical booklet PCs are equipped with multi-touch screens and pen writing recognition abilities. They are designed to be used as digital day planners, internet surfing devices, project planners, music players, and displays for video, live TV, and e-reading.
Slates
Slate computers, which resemble writing slates, are tablet PCs without a dedicated keyboard. For text input, users rely on handwriting recognition via an active digitizer, touching an on-screen keyboard using fingertips or a stylus, or using an external keyboard that can usually be attached via a wireless or USB connection.
Tablet PCs typically incorporate small (8.4–14.1 inches/21–36 centimetres) LCD screens and have been popular in vertical markets such as health care, education, hospitality and field work. Applications for field work often need a tablet PC that has rugged specifications that ensure long life by resisting heat, humidity, and drop/vibration damage. This added focus on mobility and/or ruggedness often leads to eliminating moving parts that could raise vulnerability.
Convertibles
Convertible notebooks have a base body with an attached keyboard. They more closely resemble modern laptops, and are usually heavier and larger than slates.
Typically, the base of a convertible attaches to the display at one joint called a swivel hinge or rotating hinge. The joint allows the screen to rotate through 180° and fold down on top of the keyboard to provide a flat writing surface. This design, although the most common, creates a physical point of weakness on the notebook.
Some manufacturers have attempted to overcome these weak points. The Panasonic Toughbook 19, for example, is advertised as a more durable convertible notebook. One model by Acer (the TravelMate C210) has a sliding design in which the screen slides up from the slate-like position and locks into place to provide the laptop mode.
Convertibles are by far the most popular form factor of tablet PCs, because they still offer the keyboard and pointing device (usually a trackpad) of older notebooks, for users who do not use the touchscreen display as the primary input method.
Hybrids
Hybrids, coined by users of the HP/Compaq TC1000 and TC1100 series, share the features of the slate and convertible by using a detachable keyboard that operates similarly to a convertible when attached. Hybrids are not the same as slate models with detachable keyboards. Detachable keyboards for pure slate models do not rotate to allow the tablet to rest on it like a convertible.
Tablet PCs vs. traditional notebooks
The advantages and disadvantages of tablet PCs are highly subjective measures. What appeals to one user may be exactly what disappoints another. The following are commonly cited opinions of the tablet PC platform:
Advantages
§ Use in environments not conducive to a keyboard and mouse such as lying in bed, standing, or handling with one hand.
§ Lighter weight, lower power models can function similarly to dedicated reading devices like the Amazon Kindle.
§ Touch environment makes navigation easier than conventional use of keyboard and mouse or touch pad in certain contexts such as image manipulation, or mouse oriented games.
§ Digital painting and image editing is enhanced and more realistic than painting or sketching with a mouse.
§ The ability for easier or faster entering of diagrams, mathematical notations, and symbols.
§ Allows, with the proper software, universal input, independent from different keyboard localizations.
§ Some users find it more natural and fun to use a stylus to click on objects rather than a mouse or touchpad, which are not directly connected to the pointer on screen.
Disadvantages
§ Higher cost — convertible tablet PCs can cost significantly more than their non-tablet counterparts although this premium has been predicted to fall.
§ Input speed — handwriting can be significantly slower than typing speeds, the latter of which can be as high as 50-150 WPM; however, Slideit, Swype and other technologies are able to provide alternate, speedier methods of input.
§ Screen and hinge damage risk - Tablet PCs are handled more than conventional laptops, yet are built on similar frames; in addition, since their screens also serve as input devices, they run a higher risk of screen damage via impacts and misuse. A convertible tablet PC's screen hinge often must rotate around two axes, unlike a normal laptop screen, subsequently increasing the number of possible mechanical and electrical (digitizer and video cables, embedded Wi-Fi antennas, etc.) failure points.
§ Ergonomics - a tablet PC does not provide room for a wrist rest while the screen is folded into slate mode. In addition, the user will need to move their arm constantly while writing.
§ Weaker video abilities - Most tablet PCs are equipped with embedded graphics processors instead of discrete graphics cards. In July 2010, the only tablet PC with a discrete graphics card was the HPTouchSmart tm2t, which has the ATI Mobility Radeon HD5450 as an option.
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