touch Screen

A touch screen is a computing device that combines the features of a display screen (monitor) and those of a pointing device like a mouse or trackball.
This reduces the number of devices on some systems and software to perform very well suited to ergonomic functions. Touch screens are used, for example, PDAs, GPS, MP3 players, smartphones, Nintendo DS, ticketing machines, all boxes and computers without a cashier.
A touch screen may be sensitive to more than two pressure levels with a resolution better (hybrid screen / stylus) and more than one place at one time (multitouch / Fingers)
There are several types of implementation for touch screens, each with advantages and disadvantages. The choice of either of these technologies will be based on the criteria of price, impact strength, precision or size (some are difficult to stretch big and small screen sizes).Surface Wave Technology
The technology of surface waves using ultrasonic waves traveling at the surface of the screen. These waves create an interference pattern that is modified by touching the screen. This change in the interference pattern, once detected, is processed by a controller to define a coordinate (x, y).
The major drawback of this technology stems from the fact that the slightest scratch (or even a dirt or stain) on the surface alters the interference pattern base and thus affects the accuracy of detection on the screen.Analog resistive technology [edit]Resistive touch screen
The resistive system consists of a glass plate whose surface is conductive (resistive: ITO). It is covered by a plastic film whose underside is conductive (resistive: ITO). These two layers are held apart by tiny spacers, in addition, an additional layer is added to prevent surface scratches (for example, by the pen nibs).
An electric current is induced in the two conductive faces during the operation. When the user touches with the tip of a stylus (or finger), initiate a pressure contact between the two sides electrified. The change in the electric fields of the two conductive faces to determine the coordinates of the point of contact. Once the coordinates determined by the software processing system is established.
The electrical conductivity of the two sides a little wear at each contact with each other (because of static discharge: micro sparks). Therefore, the accuracy of detecting coordinates of the hit is reduced with use. This technology requires the user to recalibrate the touch pad. This recalibration is to hide the wear of touch by spreading over its entire surface, the errors of the most used parts touch. Types of devices using this system: laptop touch screen Windows 7, the former company PALM PDA, some smartphones (HTC Tattoo, HTC TyTN II, LG Viewty ...)

Read more »

Technologie iphone

Where were you last Tuesday when Steve Jobs introduced the new iPhone cell phone? Do you remember? By listening to some people, it almost seems that the Earth has stopped spinning for several seconds. However, announcing his arrival on the cellular market, Apple only adds to an already well-stocked supply. Because on average, every two days, a new cell phone made its appearance on the international market.

With its arrival on the market in June in the U.S., the iPhone will most likely mark a point in the evolution of cellular telephony, but nothing comparable to the revolution What caused the arrival of the Macintosh in 1984 or the iPod digital music player in October 2001.
Today in the market for high-end phones, most devices on the market promises to do exactly what the iPhone. Of course, like all products endorsed by Apple, design is nice and the touch screen to delight the eye but for everything else, there are already many high-end devices on the market that allow to do exactly the same thing. Or make and receive calls, connect to the Internet, take pictures, listen to music, watching videos.
Even access to the music service iTunes Store is not new, since Apple allows some Motorola devices to connect to the service for a year. Will the lure of the iPhone is the size of the screen, which will make viewing video and browsing the Internet more enjoyable? Perhaps, but the tablet Nokia N770 offers us several months ago, same thing for his new version, the Nokia N800.
No, the secret of success of the iPhone remains the fact that it is first and foremost an Apple product which, thereby, inherits the image enjoyed by the equipment manufacturer for several years . Even its high price in U.S. dollars, $ 500 for the 4 GB version and $ 600 for the 8GB version, in fact a product of greed.
And there's the question that burns your lips from the beginning of this column. That will provide the equipment here, and when? Well, what has been said that the leadership of the cellular service provider Rogers last week, which does not announce it too soon, yes, the provider discusses with Apple. And for good reason, Rogers is the only operator to operate a GSM cellular network (Global System for Mobile Communication) in the country. Better yet, Rogers is already testing the device with some customers here. Us, do not be surprised to see the iPhone in the hands of someone in Montreal.
Regarding the date of marketing of the device is more difficult to predict at the moment, but I assume that it should be out before Christmas 2007 with us to enjoy the buzz of the moment. Understand that Apple, the priority remains the output of the device in the U.S. Cingular (now renamed from AT & T Wireless), which is expected to be high demand. However, in terms of marketing of new devices, Apple has accustomed us to delays in delivery of products during the first month of availability.
But rest assured, as Steve Jobs himself was confident of selling over ten million units in the U.S. (Canada is considered the 51st state) and in Europe during its fiscal year 2007-08, it 'll have to place equipment on the shelves of shops Rogers. As for the Asian market, the iPhone will not be available until 2008.
Contested mark
It only remains now to see how Apple will come to cope with the holder of the trademark iPhone. For the OEM Cisco owns the rights to the name iPhone since 2000 and most experts in the law of intellectual property agreement that if the case goes to court, Apple will not see the benefit . That's why Apple is already thinking of renaming the product "Apple Phone" and let the public itself to call it "iPhone", or bring himself to give a share of his winnings to Cisco. The most unfortunate in this story is that the Cisco iPhone, launched last November, does not hold a candle of the new product offered by the big boss of Apple.
In this case, Apple does exactly what it accuses of thousands of small businesses that have tried to get out on the market for products compatible with the iPod music player feature and using variations such as "i" or "pod" in the brand their product. After the Beatles played the right to use its company name, which comes from somewhere else to go from Apple Computer to simply Apple, the manufacturer now claims an exclusive right to use the term "pod" in the field of technology and music.
Last September, a young company in Houston found itself in the middle of the storm while she was distributing its software free MyPodder to allow users to manage and ensure the update of their subscriptions to podcasts from a digital music player. The day that little box has decided to offer its software in Mac version, Apple did not appreciate the initiative.
Apple has sent a legal notice to the company to indicate that Apple reserves the exclusive right to use the term "pod" in a context relating to electronic devices and software for playing media files. Since then, manufacturers had to change the name of these websites and even had to change its name, if not completely shut down in response to demands from home Apple.

Read more »

GPS technology systemen

The Global Positioning System: Towards an integrated technology in everyday life
Eric Calais - CNRS - Geosciences Azur, Sophia Antipolis

The satellite positioning system GPS is a technology that is revolutionizing many areas of industrial and scientific. The system is reliable, accurate, available anywhere and anytime, easy to use. Moreover, its growing success is associated with a steady decline in hardware prices. The time is perfect for s'interéresser GPS, progress and new opportunities opened up by this technology.
"Ladies and gentlemen, we begin our descent, please take your seats and fasten your belt." This is a phrase often heard a few minutes before the landing of an airliner. Soon after, the aircraft is in final approach and descends steadily to its destination, perfectly aligned with the direction of the track. A few minutes more and the aircraft is close enough to the ground. It rears up slightly just before touching and aterrit. Nothing special for the passengers, happy to arrive safely. However, this final approach and the landing has been made fully automatically without the intervention of the pilots, with a guidance system which are enslaved control of the plane ... And what amazing guidance system: it is Indeed, a satellite technology, the Global Positioning System, or GPS. No, this is not science fiction. This device is actually in place in the United States and complements the traditional navigation signals emitted from the ground that were until now the only way to land in conditions of minimum visibility. In France, Airbus Industries, in collaboration with Aerospatiale, Sextant Avionics and Technical Service of Air Navigation, is testing the system since October 1994. He has already proven its efficiency and high reliability, providing positioning of the aircraft with a vertical accuracy better than 1 meter.
Positioning available anytime, anywhere GPS is a satellite positioning system to determine its position, speed and direction of travel at any time and any place (see Box 1). A technological dream only 10 years ago, a reality since 1993, when the first receivers were sold to individuals. GPS has quickly been very popular with sailors, boaters as professionals. Ease of use, accuracy and reliability outperform a largely traditional navigation systems such as Deccan, Loran, Satnav, etc.. A wide range of material is currently available, suited to most needs of navigation and positioning. It provides a precision that ranges from a hundred meters to several millimeters depending on the type of receiver and the technique used (see Box 2).
A performance / cost adaptable to all needs. As for prices, there are portable receivers the size of a calculator for less than 3000 francs. Those used for shipping, if they have the "differential", worth about 10,000 francs. At the other end of the spectrum, there are geodetic quality receivers, capable of providing a location within a millimeter, for 150,000 francs. A bit expensive, it is true, but these receptors were worth twice as there are only four years. Each application, according to his needs in terms of precision, speed to result (real-time positioning or delayed), and of course the budget, will find its natural place in the range offered by the GPS.
Positioning System military hijacked by the civilian economy GPS is a U.S. military at that. However, it is accessible to any civilian who equips a suitable receiver. Technology leaders of GPS receivers are of course American. Some foreign companies, however, as the French company Sercel, have embarked on the construction of receivers and the development of integrated solutions to meet specific applications. Of course, the U.S. military reserve access to the full capabilities of GPS, and the right to degrade all or part of the system. For example in case of military conflict that would involve. Currently, however, only some of the capabilities of GPS is available to civilian users, constrain the absolute positioning accuracy in real time about 100 meters (while the U.S. military have a precision of less than 10 meters) . However, civilian applications of GPS have become so large and represent a major economic as the pressure is high so that the system is at least maintained in its current state of performance, even for the maximum precision is made available to civil users. In addition, a system very similar to the GPS was set up by Russia, GLONASS, which starts to be operational. The issue of preventing access to the GPS to hostile nations because of his losing interest if there is a competing system. Recognizing the importance of these new developments, the U.S. Vice President Al Gore said on March 29 that his government had decided "to help the fledgling industry of GPS to achieve a turnover of $ 8 billion before the end of this century. " This rapid expansion (the current turnover of GPS industry in the United States is about $ 2 billion) would be accompanied by about 100 000 new jobs, so we understand the economic potential of GPS.
Some applications to the positioning of vehicles One of the first practical applications of GPS beyond the simple positioning was implemented on the airport in Chicago, one of the busiest in the U.S.. It was not to allow pilots to position themselves in flight, as one might think, but to allow the control tower at any time to know the position of aircraft on the ground in order to better manage their travel, sequencing of takeoffs and avoid collisions, especially on foggy days. Each plane is equipped with a GPS receiver calculates its position and continuously broadcast by radio to the tower control unit. In turn, a computer receives these positions and displays in real time on screen, on a base map showing the map of the airport. A "no radar radar", in short, that allows controllers to have all the necessary information summarized on a single screen.
This idea has since been transferred and adapted to many situations where it is necessary to continuously monitor the position of vehicles from a control station which is to better manage their travel. An example that has made the press recently is that of taxis in the city of Nice. Each one is equipped with a GPS, which transmits its position to a control center. Increased efficiency, but also security. Last March, a thug had the bad idea to steal a taxi ... equipped with a GPS. Had he known, he would have understood the limited chances he had to escape the police, informed continuously and in real time of the journey!
Similarly, monitoring of large public works projects or careers can be greatly facilitated by equipping vehicles with GPS, the position is transmitted in real time to the computer of the foreman. The latter can always see the state of activity of its construction, the availability of equipment, etc.. It can react quickly if necessary as it has all of the information under the eyes, updated continuously, from his office. Now let's talk strategy and precision measurements. This type of application typically requires an accuracy of one meter. The receivers can be used to type single frequency, but will have to measure the signal phase (see Box 2). The best strategy for the lowest cost, is to equip the site with a GPS reference station that emits differential corrections to the receptors on mobile machinery. These calculate their position continuously and transmitted by radio to the control center.
Finally, coupled with GPS maps and digital traffic can already guiding vehicles. This technology is great development in Japan (see article in the April 1995 International Technologies) and begins to appear in France.
GPS, digital mapping and GIS For surveyors and surveyors, whose work is mainly the production of maps, GPS is becoming an indispensable tool. Conventional methods of positioning under the theodolite are certainly as accurate as GPS, but it offers a performance always sufficient for comfort and speed from. Measured points, for example, need not be intervisible. By placing a fixed receiver in the middle of a field map, one person, equipped with a second receiver can set dozens of points in one day. An accurate map of flood zones in a flood plain, the resumption of a municipal cadastre, delimitation of land become achievable tasks quickly, accurately, and with a reduced workforce. Software for data processing are sufficiently user-friendly and easy to use to enable the surveyor to deal in an hour or two the data collected in a full day of field measurements. A reliable and accurate results can be delivered to the customer the same day.
In addition, the result of a campaign of GPS mapping is digital, then integrated directly into a computer by software such as "GIS", or GIS. By entering into a GIS map data for a region (topography, layout of roads, cadastral boundaries, distribution of vegetation cover, etc..), One can leisurely road design overlay to the map of flood zones and evaluate the impact of a flood, an overlay map of the settlements with the risk of forest fires, etc.. In addition, the map data base is more often the satellite image, GPS has another advantage here. It allows easily the "georeference", that is to say the place a rigorous system in a mapping. Simply position on the ground, GPS, although some sites identified in the satellite image.
Towards an integrated technology in everyday life GPS technology has come to prove its reliability and accuracy. The current challenge is no longer "how to" but "what to do." The place is the imagination and the implementation of new applications of GPS to the needs and problems. For which, moreover, a precise positioning is not necessarily essential. Indeed it appears that the GPS market is driven by falling prices of hardware as an application in terms of accuracy only. The GPS is actually becoming a regular accessory of everyday life, just like a wristwatch. Proof is the concept of "Wide Area Differential GPS", which is beginning to emerge in the United States: a network of 450 reference stations will soon make differential corrections on the FM band, which will cover 90% of North America. Meter precision for an annual subscription of $ 600, which could be better?

Read more »