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THE FUTURISTIC VEHICLE

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THE FUTURISTIC VEHICLE

Abstract:

The technical Brilliance and Developments in different fields has led to a drastic change especially in the communication field. Devices with intelligence rule the world. Imbibing intelligence to these D Devices is through a system called “EMBEDDEDSYSTEMS”. It is the evolution or further development of the computing system. Its applications provide marvellous opportunities for ingenious use of C Computer technology. Almost every new system introduced is an example of Embedded System. These systems are more intelligent and autonomous. Embedded Systems are combinations of h H ardware and software that are mounted on compact electronic circuit boards integrated into devices. They are engineered or intended to perform one specific function in a specific environment. An i Important decision in the design of an embedded system is the selection of the processor(s) around which the rest of the system is to be built. It is a chip that contains a microprocessor, some m Memory & I/O interface circuitry useful in embedded applications and is often called an ‘EMBEDDED PROCESSOR’ or ‘MICRO CONTROLLER’ chips as they perform important control functions, and are b Based on micro controller. The current topic “EMBEDDED VEHICLE” that we are going to present is one of the fine examples of Embedded System.

Autonomous car:

There are many paradigm shifts taking place due to information explosion and the concept of autonomous vehicle is one shift. The car, which is embedded, can simulate the human driver completely and direct the vehicle on the road. Autonomous vehicle is the drastic change in technical brilliance and developments in different fields with EMBEDDED SYSTEM as pioneer. In future by using Embedded vehicles we have the possibility to reduce the accidents and we are capable to reduce the use of fuel. so that we can reduce environmental pollution. We hope that this technology will exists in near future

Introduction:

The termembedded system is quite a complex one. Simply it is a combination of hardware and software that forms the component of a larger system, this in turn is programmed to Perform a range of dedicated functions usually with a minimal operator intervention. In embedded systems the hardware is normally unique to a given application, computer chips are embedded into t The control electronics to manage the products functionality.

Embedded systems are rapidly becoming a catalyst for change in computing data communications, telecommunications, industrial control and Entertainment sectors. New innovative applications in these as well as other areas such as home networking and car infotainment will roll out in the near feature.

The fine art of automation:

We load the code of our destination in the dashboard computer and turn the car on, while we remain seated carefree on the rear seats. Then its all the job of the ‘unknown’ to Drive it on the roads, bridges, thought the bazaars, past the crossings to the destination, without getting challenged even once for traffic rule violations.

A fully computerized car capable of doing almost every thing a car lover would want to. Almost all automobiles will interact with computer on dashboards. From ordering pizza to booking tickets at the nearest theatre, things would be as easy as giving orders to your servant. As a matter of fact, vehicles all over the world are now fitted with intelligent devices that make the vehicles to respond to Various factors –be it climate control, sudden accelerations or braking or even self-repair of modules.

The finger print technologies have been introduced to enter and start your car with the touch of a finger. The fingerprint, which is acting as a key, would trigger a check of the mirrors, steering Wheel, radio and temperature to ensure that they're the way you like them. The convenience of fingerprint recognition technology comes with heightened security. Unlike personal identification n numbers, passwords and keys, each person's unique fingerprints can't be duplicated, lost or forgotten.

Description:

As stated above that a vehicle can run by itself with out the intervention of human beings by the embedded intelligence in it. For this purpose Global Positioning System (G.P.S) using satellites can provide positioning information and proves to be a versatile all-time. For still higher accuracy wide area differential GPS is used, which offers a robust system that readily deals with selective availability errors and satellite clock errors.

The models for GPS also include aiding sensors, e.g. dead reckoning, radar and camera. A computer is simply required to feed destination into a dashboard computer. highly sensitive actuators simulate a human driver completely and direct the vehicle on the road. The vehicle transmitter broadcasts its position and velocity to other immediate participants for Collision-avoidance and lane changing manoeuvres. Forward and reverse motions and u-turns are precisely achieved as per route guidance requirements. Furthermore, an accurate steering control is obtained using Pulse Code Modulation technique and acceleration/braking control is successfully implemented using learning adaptive system.

The reliability, efficiency and cost effectiveness of an autonomous vehicle depend mainly on how judiciously its navigation sensors, perception unit and computer control is incorporated.

The driver’s activity is influenced by several factors that depend on driver itself and is environment such as traffic density, traffic status, time of travel and weather. The vehicle is required to blend its environmental perception capabilities with its intelligent controls in order to affect optimal path-planning strategies that not only avoid obstacles but also minimize criteria such as time of travel, fuel consumption, exposure to pollution/danger, etc

however basic driving functions consists of lane-keeping, safe distance maintenance, timely lane changing and overtaking. The key to all these driving tasks is collision avoidance. The Master Control Station (MCS) receives the positioning information from the satellite by employing WADGPS concept. The MCS is linked to GPS instrumented position location systems (PLS) installed on the autonomous vehicles through a data link sub system (DLS). The DLS can either use VHF or UHF or L-band, incorporating time division multiple access protocol to handle on the roads. A block forward error correction code is employed to protect and maintain the message integrity.

The desired destination and starting position of the vehicle together with the time of travel, manifest an optimal route on the road network. Once the vehicle commences the journey the sensors continuously keep track of the direction and displacement of the vehicle initial calibration is a little crucial for dead reckoning performance; how ever a feed back calibration indicated in fig suggested obtaining distance accuracy better than 99.9 percent. The new generation microprocessors promises further increase in system capabilities while simultaneously shrinking both volume and power consumption of the autonomous vehicle embedded system. The digital road maps, available on CD-ROM’s have substantially increased safety of automobiles. These maps along with GPS navigation provide a feasible solution to autonomous vehicle system.

The expert system technologies are integrated with digital maps along with the CCD camera images, magnetic compass, and the GPS system, for obtaining a real time intelligent decision support navigation package.

The integration of GPS and communication suggests an efficient transportation system for increasing the road traffic safety smooth driving without traffic jams and a comfortable driving environment. Further more the autonomous vehicle relies on such intelligent system integration that leads to complete collision free in time of real time situation. The internal platform and rate gyro and accelerometer package keeps the vehicles central processing unit (CPU) well informed about the incremental changes in the vehicles parameters. The wheel odometers provide the vehicle travelling distances by multiplying the number of electronically generated pulses by a constant, depending upon wheels perimeter. The information concerning deviation from the road centre is obtained by magnetic as well as optical sensors, and fed to the CPU. The GPS receiver updates the vehicles position and velocity to centimeter/decimeter levels as required for the lateral or longitudinal control actions. The autonomous vehicle embedded software mission finally yields the estimates.

for throttle and heading angle increments for a safe and accident free Manoeuvre. The following figure gives an indication of all the technologies used in a car.

Advantages and comforts:

The adoptive cruise control ACC technology used in the cars from automobile makers keeps advancing to new levels of safety. In microwave radar unit there is a laser transceiver, fixed on the front of the car to determine the distance and relative speed of any vehicle in its path, which keeps safe distances from other vehicles on the busy roads. The driver can set the speed of his car and the distance between his and other cars. When traffic slows down vehicle speed is altered using moderate braking to maintain a constant distance between his and other cars.

2. In advanced systems just in the case the driver over speeds or suddenly falls over and guides the car to a safe halt. And if you have programmed it right, the GPS in the car would take you to your destination .so, right from brakes to automatic traction control to air bags and fuel-air mixture control, the intelligence takes over.

3. A few advanced car prototypes with embedded systems have been tried and tested where even if a smart thief has managed to break in through the car, the car doesn’t start up even if it does the computer I the car would lock the steering wheel and cut-off the fuel injection supply … in the mean time a signal is set to the nearest police station and the owner informing them about the thief.

4. Some designs now include so-called "pre-safe" systems, which sense possible collisions in advance based on emergency braking, skidding, and

Sudden evasive maneuvers. They will prepare a car by automatically moving the front seat either backward or forward for the safest distance from the instrument panel, adjusting the seat belt for the correct tension, and even closing the sunroof in case of a potential rollover. The idea is to "cradle" the car's occupants for maximum safety.

Indian efforts in embedded system development: -

Our India too entered into the field of embedded systems and had great developments in this field. it got marvellous results in the field of “Telematics” which is a part of technology used in cars. Total telematics experience is what they are looking for simply put telematics is the vehicles capability to communicate with the outside world and or the vehicle operator. It is a combination of telecommunication and computing

Mistral software, which was developed in India, has text-to-speech and speech recognition technologies to give the car occupants the ultimate comfort. So whenever there is a call on your mobile. You need not get jump at the very onset of the call. Relax the computer in the cars dashboard would do the job for you.

GPS navigation guides you through the traffic. The GPS interface in the car pinpoints your exact location on a map. In case the GPS signal cant be received due to high density of tall buildings or other magnetic interface, the ‘dead reckoning ‘ technique, which works for short durations guides you effectively. The system is also loaded with GSM/CDMA protocol standards further modified on the CANBUS standard t give uninterrupted information. Another device called the array microphone cuts off the surrounding noise and allows the speaker to communicate effectively. The person at the other end hears the voice of the speaker without any outside interference.

Conclusion:

With the heights of the technology autonomous car is no more a myth. It’s a reality! We would like to present that there must be further developments in this technology to make autonomous car more common all over the world. This can be happened by making the autonomous easy to operate for the user and the designers should concentrate more in producing autonomous cars, which should not cost a lot, they should in the vicinity of customers’ budget. With this type of vehicles there will be great advantages in the coming feature. Due to speed control technique, accident free driving is possible and fuel savage is also made possible by the technique, which will make the car to travel through shortest path. In the near future, autonomous car become more common all over the world with many more advantages.

. D.v.sai kumar

2nd EEE(B)

12H75A0222

Solar Power a boom for Electricity generation in India

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Solar Power a boom for Electricity generation in India

India is densely populated and has high solar insulations, an ideal combination for using solar Power in India. The illustration of history of Solar Power shows how solar power has evolved through government’s policies as well as increasing financial benefit as traditional energy sources have become more expensive and costs of going solar have dramatically decreased.
In the solar energy sector, some large projects have been proposed, and a 35,000 km2 area of the TharDesert has been set aside for solar power projects, sufficient to generate700 GW to 2,100 GW.

Applications of Solar Technology:

Solar energy refers primarily to the use of solar radiation for practical ends. However, all renewable energies, other than geothermal and tidal, derive their energy from the sun.
Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.

Solar Power in Gujarath , Maharastra and Rajasthan:

Gujarat has been a leader in solar power generation and contributes 2/3rd of the 900 MW of photovoltaic’s in the country. The State has commissioned Asia’s biggest solar park at Charanka village. The park is already generating 214 MW solar power out of its total planned capacity of 500 MW.
The Shri Sai Baba Sansthan Trust has world's largest solar steam system. It was constructed at the Shirdi shrine at an estimated cost of Rs.1.33 crore, Rs.58.4 lakh of which was paid as a subsidy by the renewable energy ministry. The system is used to cook 50,000 meals per day for pilgrims visiting the shrine, resulting in annual savings of 100,000 kg of cooking gas and has been designed to generate steam for cooking even in the absence of electricity to run the feed water pump for circulating water in the system. The project to install and commission the system was completed in seven months and the system has a design life of 25 years.
Next to Gujarat, Rajasthan is India's sunniest state, and many solar projects have been proposed. The 40 MW photovoltaic Dhirubhai Ambani Solar Park was completed in April 2012. A 250 MW compact linear fresnel reflector (CLFR) plant is under construction, consisting of two 125 MW sections.

APPLICATIONS:
Rural electrification:
Lack of electricity infrastructure is one of the main hurdles in the development of rural India. India's grid system is considerably under-developed, with major sections of its populace still surviving off-grid. As of 2004 there are about 80,000 unelectrified villages in the country. Of these villages, 18,000 could not be electrified through extension of the conventional grid. A target for electrifying 5,000 such villages was set for the Tenth National Five Year Plan (2002–2007). As of 2004, more than 2,700 villages and hamlets.
Developments in cheap solar technology are considered as a potential alternative that allows an electricity infrastructure consisting of a network of local-grid clusters with distributed electricity generation. It could allow bypassing (or at least relieving) the need to install expensive, loss, long-distance, centralized power delivery systems and yet bring cheap electricity to the masses.

Solar lamps and lighting:
By 2012 910,504 solar lanterns and 861,654 solar powered home lights have been installed. These typically replace kerosene lamps and can be purchased for the cost of a few months worth of kerosene through a small loan. The Ministry of New and Renewable Energy is offering a 30% to 40% subsidy for the cost of lanterns, home lights and small systems up to 210 Wp. 20 million solar lamps are expected by 2022.

Agricultural support:                                 Solar PV water pumping systems are used for irrigation and drinking water. The majority of the pumps are fitted with a 200–3,000 watt motor that are powered with 1,800 Wp PV array which can deliver about 140,000 liters of water per day from a total head of 10 meters. By 30 September, 2006, a total of 7,068 solar PV water pumping systems had been installed and by March 2012, 7,771 had been installed.
Solar driers are used to dry harvests before storage.

Solar water heaters:
                               Bangalore has the largest deployment of rooftop solar water heaters in India. These heaters generate an energy equivalent of 200 MW every day .
Bangalore is also the first city in the country to put in place an incentive mechanism by providing a rebate of 50 on monthly electricity bills for residents using roof-top thermal systems. These systems are now mandatory for all new structures.
Pune, another city in the western part of India, has also recently made installation of solar water heaters in new buildings mandatory.


Solar water heaters facing sun to maximize gain.

Challenges and Oppurtunities:

Land is a scarce resource in India and per capita land availability is low. Dedication of land area for exclusive installation of solar arrays might have to compete with other necessities that require land. The amount of land required for utility-scale solar power plants currently approximately 1 km2 for every 20–60 megawatts (MW) generated could pose a strain on India's available land resource. The architecture more suitable for most of India would be a highly distributed set of individual rooftop power generation systems, all connected via a local grid. However, erecting such an infrastructure, which does not enjoy the economies of scale possible in mass, utility-scale, solar panel deployment, needs the market price of solar technology deployment to substantially decline, so that it attracts the individual and average family size household consumer. That might be possible in the future, because PV is projected to continue its current cost reductions for the next decades and be able to compete with fossil fuel.
Some noted think-tanks recommend that India should adopt a policy of developing solar power as a dominant component of the renewable energy mix, since being a densely populated region in the sunny tropical belt ,the subcontinent has the ideal combination of both high solar insolation and therefore a big potential consumer base density. In one of the analyzed scenarios, India can make renewable resources such as solar the backbone of its economy by 2050, reining in its long-term carbon emissions without compromising its economic growth potential.

   By

   V.MAHESH
                                    10H71A0218
   3rd EEE

WHY CAN'T WE DO THIS.....?

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WHY CAN'T WE DO THIS.....?

Hello frnds here I’ve a project for our upcoming generation and which is more beneficial for us. That is… regarding our natural resources. The present situation of our generation is neither saving the resources which we are having naturally now nor utilizing in proper way as per my knowledge. And my idea is to run a car or an auto rickshaw by using our three natural resources:1)solar energy, 2)wind energy, and 3)frictional energy. By converting these three resources into electrical energy.
How does it work?
1.A solar array absorbs the rays which emits from the sun and these arrays transmits the power to power trackers and then these trackers are connected to batteries then batteries are connected to motor controller to control the motor from motor connected to wheels as shown in the below figure.

2. Similarly two fans will be arranged at front exhaust rack of the car. The fan will get rotated while the car is moving forward, there energy will be produced from the fans and then it will be converted to electrical energy through power trackers.
3. Frictional energy we can collect this from tires while the car is at running position. When the tire is rotating some frictional force will be produced and it will convert to electrical energy through dynamos which plays major role in converting frictional energy to electrical energy. The converted energies will be stored in batteries.

The main components of this project are:
Solar array
Power trackers
Batteries
Electric motor & controller
Two fans
Dynamos.

What happens if there is no sunlight?
If there is no sun light, the emergency batteries will be used. For example there is a large cloud cover the sky, these emergency batteries will be used.

USES:
There are many uses

The transports like auto rickshaw’s and taxis is more in use in India if this technology is used we can reduce major part of pollution
We can save the resources like petrol diesel & gas which we are using in huge amount
The use of renewable resources of energy is becoming very essential today. You have to save energy everywhere possible to save the Earth. The use energy of wind, water and sun is making a way into your daily life now.
Solar panels can also used to cool the temperature inside a car on hot summer days. They work on the ventilation system of the car and you do not need to switch on the air-conditioner to cool off.

md.akram(10H71A0203)

An Introduction to Robotics Technology

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An Introduction to Robotics Technology

An Introduction to Robotics Technology

The word "Robot" originates from the Czech word for forced labour. A Robot is a mechanical device that can perform tasks automatically. The current mechanical robots of popular culture are not much different from these fictional biological creations. Basically a robot consists of:- A mechanical device, such as a wheeled platform, arm, or other construction, capable of interacting with its environment.

A Robot need to follow three laws of robotics which are formed by Father of Robotics ‘Isaac Asimov’

A robot may not injure a human being or, through in action, allow a human being to come to harm.
A robot must obey the orders given to it by human beings, except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.

Sensors on or around the device that are able to sense the environment and give useful feedback to the device. Systems that process sensory input in the context of the device's current situation and instruct the device to perform actions in response to the situation. In the manufacturing field, robot development has focused on engineering robotic arms that perform manufacturing processes.
Safety - Robotics have been developed to handle nuclear and radioactive chemicals for many different uses including nuclear weapons, power plants, environmental cleanup, and the processing of certain drugs.
A variety of electric motors provide power to robots, allowing them to move material, parts, tools, or specialized devices with various programmed motions.
Gears and chains are mechanical platforms that provide a strong and accurate way to transmit rotary motion from one place to another, possibly changing it along the way. The speed change between two gears depends upon the number of teeth on each gear. When a powered gear goes through a full rotation, it pulls the chain by the number of teeth on that gear.
Pulleys and belts, two other types of mechanical platforms used in robots, work the same way as gears and chains.
Power supplies are generally provided by two types of battery. Primary batteries are used once and then discarded, secondary batteries operate from a reversible chemical reaction and can be recharged several times.
There are two major hardware platforms in a robot. The mechanical platform of unregulated voltages, power and back-EMF spikes, and the electronic platform of clean power and 5-volt signals.
Robots react according to a basic temporal measurement, requiring different kinds of sensors. In most systems a sense of time is built in through the circuits and programming. A sensor receives energy and transmits a signal to a display or computer. Sensors use transducers to change the input signal (sound, light, pressure, temperature, etc.) into an analog or digital form capable of being used by a robot. We have Logical Sensors, Proprioceptive Sensors, Proximity Sensors and Infrared (IR) Sensors etc.
Microcontrollers (MCUs) are intelligent electronic devices used inside robots. They deliver functions similar to those performed by a microprocessor (central processing unit, or CPU) inside a personal computer. There are four basic aspects of a microcontroller - speed, size, memory, and other.
Animatronics systems are robotic systems which mimic and look like humans. An android is an anthropomorphic robot - in other words, a robot that looks like a human.
OROCOS (Open ROBOT CONTROL Software) is an effort to start up an open source robot control software project.
Pneumatics is the name for fluid power used in a large number of commercial robots. To live among people, robots need to handle complex social tasks.
Robots are used in Industries, military, serving, welding, painting, drilling, sanding, cutting, and moving tasks.
At present there are about 250,000 robots in use throughout the world. About 65 percent of these are located in Japan. The United States, the second-largest user of robots, has about 14 percent.

Advantages of robots:

Robotics and automations can increase safety, reliability, production amount, profit, quality and quantity of products in a lot of cases.
They can do jobs in dangerous situations and save lives of thousands of people.
They do not care about the comfort of their environment. Human needs such as hunger or depression have no meanings for them. They do not get tired.
Their accuracy is so high and is in the range of millimetres or even micrometers.

Ch.Krishna Kanth
10H71A0217

DISPOSABLE EMAIL ADDRESS

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DISPOSABLE EMAIL ADDRESS

DISPOSABLE EMAIL ADDRESS

Disposable email addressing (DEA) refers to an alternative way of sharing and managing email addressing. DEA aims to set up a new, unique email address for every contact or entity, making a point-to-point connection between the sender and the recipient. Subsequently, if anyone compromises the address or utilises it in connection with any email abuse, the address-owner can easily cancel (or "dispose" of) it without affecting any other contact. Following the cancellation or replacement of a disposable emailaddress, the (ex-)owner need notify no more than one person/contact of the change.
Disposable email addressing, in essence, sets up a different, unique DEA for every sender/recipient combination. It operates most usefully in situations where someone may sell or release an email address to spam lists or to other unscrupulous entities. The most common situations of this type involve online registrations for things such as discussion groups, bulletin boards, chat rooms, online shopping, and file hosting services. In a time when email spam has become an everyday nuisance, and when identity theft threatens, DEAs can serve as a convenient tool for keeping network users safe and sane.
Most likely, but not always, cancellation of a disposable email address takes place because someone starts to use the address in an illegitimate manner. This may occur through the accidental release of an email to a spam list, or because the original recipient unscrupulously and deliberately obtained it deceptively. Alternatively, the user may simply decide not to receive further correspondence from that company. Whatever the cause, DEA allows the address owner to take unilateral action by simply cancelling the address in question. Later, the owner can determine whether to update the recipient or not.
For the sake of convenience, disposable email addresses typically forward to one or more real email mailboxes where the owner receives and reads messages. The contact with whom a DEA is shared never needs to know the real email address of the user. If a database manages the DEA, it can also quickly identify the expected sender of each message by retrieving the associated contact name of each unique DEA. Used properly, DEA can also help identify which recipients handle email addresses in a careless or illegitimate manner. Moreover, it can serve as an effective tool for spotting counterfeit messages, or phishers.
Advantages over traditional email:
Ideally, owners share a DEA once with each contact/entity. Thus, if the DEA should ever change, only one entity needs to be updated. By comparison, the traditional practice of giving the same email address to multiple recipients means that if that address subsequently changes, many legitimate recipients will need to receive notification of the change and to update their records – a potentially tedious process.
Additionally, because access has been narrowed down to one contact, that entity then becomes the most likely point of compromise for any spam that account receives (see "filtering" below for exceptions). This allows users to determine firsthand the trustworthiness of the people they share their DEAs with. "Safe" DEAs that have not been abused can be forwarded to a real email account, while messages sent to "compromised" DEAs can be routed to a special folder, sent to the trash, held for spam filtering, or returned undeliverable if the DEA is deleted outright.
Further, because DEAs serve as a layer of indirection between the sender and recipient, if the DEA user's actual email address changes, for instance moving from a university address to a local ISP, then the user need only update the DEA service provider of the change, and all outstanding DEAs will continue to function without updating.
Security and filtering:
It is possible for spammers to "guess" commonly used DEAs by trying addresses in the form of <CommonCompanyName@RandomName.DEAServiceProvider.com> or other widely used formats. This is especially likely if a user's subdomain (The "RandomName" part) has already been posted publicly somewhere. To combat this, users can make their email addresses more obscure through using random names, checksums, a mutated form of a name, or some combination of the above. A harder-to-guess example might be <CompanyName.Checksum@YourDomain.DEAServiceProvider.com> or <RandomTextCompanyNameRandomText@YourDomain.DEAServiceProvider.com>. There is an obvious tradeoff in that the more obscure an address is, the harder it will be for users to remember and quickly type it. Mentally computed checksums may help with this
Multiple email aliases:

Another approach is to register one main and many auxiliary email addresses which will forward all mail to the main address i.e. being used as aliases to the main address. The advantage of this approach is that the user can easily detect which auxiliary email is 'leaking' with spam and block or dispose it. It requires additional time to set up forwarding. However, this method allows storage and access of all emails from a single main account, although to manage forwarding the user has to remember the password for each alias.
A variation on this is to use a catch-all address then forward to the real mailbox using wildcards. A lot of mail servers allow the use of '*' meaning 'any number of characters'. This makes the whitelist automatic and only requires the administrator to update the blacklist occasionally. In effect the user has one address but it contains wild cards e.g.; 'me.*@my.domain' which will match any incoming address that starts with 'me.' and ends with '@my.domain'. This is very similar to the '+' notation but may be even less obvious since the address appears completely normal.
Concerns:

Many forum and wiki administrators dislike DEAs because they obfuscate the identity of the members and make maintaining member control difficult. As an example, trolls, vandals and other users that may have been banned may use throwaway email addresses to get around attempts to ban them.Using a DEA provider only makes this easier; the same convenience with which a person may create a DEA to filter spam also applies to trolls. For this reason, most[citation needed] forum programs have functionality to make it easier to ban DEAs. As a result, forum, wiki administrators, blog owners, and indeed any public site requiring user names may have a compelling reason to ban DEAs. Site operators that expect to generate revenue from the sales of gathered user email addresses may choose to ban DEAs as well due to the low market value of such addresses, in which case use of DEAs would serve its purpose, and the user would be well justified in using it.
Banning DEAs might not be as effective at deterring undesirable users as the administrators might hope – SPAMmers, vandals and trolls who routinely engage in such activities can easily generate brand new email addresses, even legitimate-looking ones, using throwaway domains or creating new accounts with free email services. This would be more of a problem for legitimate DEA users, for whom the concept of a "real" or "permanent" address may well not exist, and demands for one are strange, suspicious and inconvenient, and creating a differently structured alias or account may be varying degrees of hassle.
More effective techniques for controlling undesirables without inconveniences to legitimate DEA users might include: recognizing legitimate DEAs for what they are (they usually have a proper domain and a fixed prefix or suffix), distinguishing them from short-lived, random throwaway address patterns or domains used by undesirables, wildcard banning (e.g. if a real person Jonh Smith, using DEA, needs to be banned, he can be banned as john.smith*@(domain) or even *@(domain), based on their DEA pattern).
As with any kind of threat and defence measures, no attempts to use or thwart DEAs are fool-proof – any filtering method is bound to result in some false positives (legitimate users getting banned), and some false negatives (undesirables getting through, and legitimate users managing to come up with a DEA pattern getting around limitations imposed by site administrators). This is because the email address may be partly or fully defined by the user, made to appear as "permanent"-looking as needed, or made to avoid a particular pattern, defeating any filtering because for all intents and purposes it is not different from a permanent one, despite being limited to one purpose.
Caught in the crossfire between Internet undesirables and administrative and user attempts to deal with them, DEA providers have trouble presenting a total solution. A user may find it necessary to come up with a conventional-looking e-mail address (or create a separate mailbox in the worst case) to a public/commercial entity if required. There is always uncertainty about the trustworthiness and reputation of the site administrators, the availability of options to hide e-mail addresses, the existence/enforcement of an acceptable privacy policy and the chance that the site may one day be compromised or transferred to new owners. Even the largest and otherwise reputable companies have been compromised or resorted to sending SPAM or giving away emails to third parties. Human correspondent's computer or mailbox may get compromised by malware and have their address book stolen and sold to spammers.
A DEA email address pattern might end up being longer and more complicated, cryptic-looking, more difficult to write down on paper or type in, especially in situations on the go, where speed and legibility may be a concern.Where DEA checksums are involved, it may require online or offline access to generate one, or an option to bypass it.Recipient might be more likely to make a mistake in a complicated email address when typing it in for subsequent use.

B.RAMA RAO

10H71A0256