Augmented Reality by Rohit Sharma

Augmented reality is one of the newest innovations in the electronics industry. It superimposes graphics, audio and other sense enhancements from computer screens onto real time environments. Augmented reality goes far beyond the static graphics technology of television where the graphics imposed do not change with the perspective. Augmented reality systems superimpose graphics for every perspective and adjust to every movement of the user’s head and eyes. Augmented Reality (AR) is a growing area in virtual reality research. The world environment around us provides a wealth of information that is difficult to duplicate in a computer. This is evidenced by the worlds used in virtual environments. Either these worlds are very simplistic such as the environments created for immersive entertainment and games, or the system that can create a more realistic environment has a million dollar price tag such as flight simulators. An augmented reality system generates a composite view for the user. It is a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information.In all those applications the augmented reality presented to the user enhances that person’s performance in and perception of the world. The ultimate goal is to create a system such that the user can not tell the difference between the real world and the virtual augmentation of it. To the user of this ultimate system it would appear that he is looking at a single real scene.It depicts the merging and correct registration of data from a pre-operative imaging study onto the patient’s head. Providing this view to a surgeon in the operating theater would enhance their performance and possibly eliminate the need for any other calibration fixtures during the procedure.Virtual reality is a technology that encompasses a broad spectrum of ideas. It defines an umbrella under which many researchers and companies express their work. The phrase was originated by Jaron Lanier the founder of VPL Research one of the original companies selling virtual reality systems. The term was defined as “a computer generated, interactive, three-dimensional environment in which a person is immersed.There are three key points in this definition. First, this virtual environment is a computer generated three-dimensional scene which requires high performance computer graphics to provide an adequate level of realism. The second point is that the virtual world is interactive. A user requires real-time response from the system to be able to interact with it in an effective manner. The last point is that the user is immersed in this virtual environment. One of the identifying marks of a virtual reality system is the head mounted display worn by users. These displays block out all the external world and present to the wearer a view that is under the complete control of the computer. The user is completely immersed in an artificial world and becomes divorced from the real environment. For this immersion to appear realistic the virtual reality system must accurately sense how the user is moving and determine what effect that will have on the scene being rendered in the head mounted display.The computer generated virtual objects must be accurately registered with the real world in all dimensions. Errors in this registration will prevent the user from seeing the real and virtual images as fused. The correct registration must also be maintained while the user moves about within the real environment. Discrepancies or changes in the apparent registration will range from distracting which makes working with the augmented view more difficult, to physically disturbing for the user making the system completely unusable. An immersive virtual reality system must maintain registration so that changes in the rendered scene match with the perceptions of the user. Any errors here are conflicts between the visual system and the kinesthetic or proprioceptive systems.The real world and a totally virtual environment are at the two ends of this continuum with the middle region called Mixed Reality. Augmented reality lies near the real world end of the line with the predominate perception being the real world augmented by computer generated data. Augmented virtuality is a term created by Milgram to identify systems which are mostly synthetic with some real world imagery added such as texture mapping video onto virtual objects. This is a distinction that will fade as the technology improves and the virtual elements in the scene become less distinguishable from the real ones.

by Rohit Sharma for Gyan.com

Asteroid to come near Earth in 22 years On Tuesday January 29th 2008

Special Report

Since it formed over 4.5 billion years ago, Earth has been hit many times by asteroids and comets whose orbits bring them into the inner solar system. These objects, collectively known as Near Earth Objects or NEOs, still pose a danger to Earth today. Depending on the size of the impacting object, such a collision can cause massive damage on local to global scales. There is no doubt that sometime in the future Earth will suffer another cosmic impact; the only question is “when?”. There is strong scientific evidence that cosmic collisions have played a major role in the mass extinctions documented in Earth’s fossil record. That such cosmic collisions can still occur today was demonstrated graphically in 1994 when Comet Shoemaker-Levy 9 broke apart and 21 fragments, some as large as 2 km in diameter, crashed into the atmosphere of Jupiter. If these fragments had hit Earth instead, we would have suffered global catastrophes of the kind that inspire science fiction movies. The dangers posed by these intruders in the inner solar system are now the subject of serious scientific investigation. Observations by astronomers tracking near-Earth asteroids have raised a new object to the top of the Earth-threat list.

The asteroid could strike the Earth in 2102. However, Don Yeomans, manager of NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, California, US, told New Scientist: “The most likely situation, by far, is that additional observations will bring it back down to a zero.”

He adds: “We’re more likely to be hit between now and then by an object that we don’t know about.”

On 23 February, new observations allowed researchers to more accurately calculate the orbit of the asteroid, named 2004 VD17, which was originally detected by the Massachusetts Institute of Technology’s LINEAR project. Since the improvement did not rule out a potential collision with the Earth on 4 May 2102, they increased the asteroid’s rating to level 2 on the Torino Scale, a relatively rare event. Since 1998, NASA has had a US Congressional mandate to locate 90% of all NEOs of 1 kilometer or larger by 2008. Yeomans says that 830 out of a predicted 1100 have been found so far, along with thousands of smaller objects. The largest asteroid to come near the Earth in more than 20 years will make its closest approach on Tuesday, venturing as close as 1.4 times the distance to the Moon. Already, the first radar observations of the space rock reveal it may have formed from two separate asteroids that fell together and stuck.

The asteroid, named 2007 TU24, was discovered by the Catalina Sky Survey in Arizona, US, on 11 October 2007. Based on its apparent brightness, astronomers estimated that it was between 150 and 600 meters wide, but it has been too far away for ground-based telescopes to resolve it and determine its actual size and shape.

However, on Wednesday, it came close enough to the Earth – about 11 times the Moon’s distance – for radar signals to be bounced off its surface. Five hours of observations using NASA’s Goldstone radio telescope in California, US, reveal that the asteroid is about 250 meters wide.

The last time an object of about the same size was observed to approach Earth at about the same distance was in September 1985, says Don Yeomans, head of NASA’s Near Earth Object programme at the Jet Propulsion Laboratory in Pasadena, California, US. “This will be the closest approach by a known asteroid of this size or larger until 2027,” he adds.

But similar close passes probably occur more often and simply go undetected. “There’s a lot of objects zipping by that are not seen,” Yeomans told gyan.com, adding that about 7000 asteroids of about the same size are expected to venture near Earth’s orbit, and only 20% have been discovered so far.

The Goldstone observations have not only helped pin down the asteroid’s size, but also its orbit, says JPL’s Steven Ostro, who led the radar observations. “We can guarantee absolutely that there’s zero chance of any hazardous close approaches to Earth until 2170.”

Spinning rock

Moreover, the asteroid “has a very interesting shape – we see asymmetries and evidence for concavities”, he told gyan.com He says the preliminary images hint that 2007 TU24 may be a so-called contact binary – created when two asteroids orbiting each other lose enough energy to eventually “fall into each other”. He says about 10% of known near-Earth asteroids have shapes that suggest they were formed by such mergers and another 10 to 15% have orbiting partners.

The radar observations also suggest the asteroid is rotating slowly – perhaps once every 10 to 30 hours, he estimates based on the initial observations. Studying rotation rates can provide clues about whether an asteroid is a solid rock or a loose collection of rubble, says Yeomans. That’s because asteroids that rotate faster than about once every 2.2 hours would fly apart if they were rubble piles.

Since 2007 TU24’s rate is slower than that, “it doesn’t tell us anything about whether it’s a monolithic rock or a rubble pile”, says JPL’s Lance Benner.

If a particular space rock appeared to be on a collision course with Earth, knowing its size, shape and rotation rate would also be crucial for planning ways to deflect it, says Ostro. “If we had to change its orbit, we’d have to figure out what kind of object we’re dealing with,” he says.

Early detection

Fortunately, 2007 TU24 will come no closer than 1.4 times the Moon’s distance. But its discovery only a few months before its closest approach to Earth highlights the importance of finding potentially dangerous space rocks, astronomers say. Recent research suggests small asteroids, just a few tens of meters across, can cause significant destruction if they impact the Earth.

Currently, NASA is hoping to turn up 90% of potentially hazardous asteroids larger than 1 kilometer wide by the end of 2008. But it says it does not have the funding to comply with a directive by the US Congress to find 90% of all space rocks down to 140 meters across. “If we could do that, then 99% of the risk associated with all near-Earth objects of all sizes would be retired,” says Yeomans, explaining that the rocks would be discovered early enough to deflect them.

Further radar observations of 2007 TU24 will be made with the giant Arecibo radio telescope in Puerto Rico when the rock is much closer to Earth. And for a brief time, amateur observers with telescopes 8 centimeters (3 inches) or larger should be able to see the asteroid under good observing conditions on the night of 29-30 January. Its closest approach will take place on the 29th at 0833 GMT.

Gyan.com

 

 

 

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14वे स्टार स्क्रीन अवार्ड पुरस्कर

14वे स्टार स्क्रीन अवार्ड पुरस्कर

कल 27-1-2008 रात्रि 8 बजे स्टार प्ल्स पर 14वे स्टार स्क्रीन अवार्ड का प्रसारण किया गया था।कार्यक्रम के मध्य मे अभिनेता साज्जिद खान ने जिस तरह से हिन्दी का उपहास उडाया उसे देख कर ना सिर्फ़ दुख हुआ अतः जिस हिन्दी फ़िल्मो की वजह से ये सितारे इतने मशहूर होते है।उसी हिन्दी भाषा का खुले आम मुख्यमंत्री श्री विलास राव देशमुख़ के सम्मुख उपहास व आपत्ति जनक वार्ता का उप्योग किया गया।दुख इस बात का है कि जिस भाषा की वजह से इनकी रोज़ि रोटि चलती है उसी भाषा के साथ इतना बड़ा खिलवाड़ कोइ कैसे कर सकता हें। फ़िल्मो मे पुरी तरह से हिन्दी का उप्योग करने के बाद अवार्ड समारोह मे English मे स्पीच दे कर झुठी वाह वाही लेना ओर हिन्दी भाषा का सार्वजनिक रूप से तिरस्कार करना व मजाक उडा के ये सितारे किन की नज़रो अपने को महान बना रहे हें। यदि देश के सभ्य व वरिष्ठ नागरिक व समाज के प्रतिष्ठित नेतागण भी अगर इस तरह के समारोह मे सम्मिलित हो कर देश की राष्ट्रीय भाषा का इस तरह से धज्जियाँ उड्ते देख सकते Click Here to Viewhttp://www.radiosargam.com/films/archives/10426/videos-14th-annual-star-screen-awards.html/6  वे इस देश को किसी भी स्तिथि तक ले जा सकते है।

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