The advantages and disadvantages of fingerprint recognition and iris recognition and their applications
Compared with fingerprint recognition, iris recognition is more complex than texture, which greatly increases security and accuracy. More importantly, its verification mechanism needs living support. This allows criminals to copy the iris texture to pass the verification. The possibility is almost zero, in addition, even if the lawless elements remove the victim's eyes it cannot be verified.
Is fingerprint recognition relatively insignificant in comparison to iris recognition? Of course, fingerprint recognition has become the most popular biometric application in the current mobile phone industry. These are three reasons. First of all, its security has certain guarantees. Compared with traditional password input methods, its safety and convenience are self-evident; secondly, its implementation is technically simpler, that is, it has a low threshold. Facilitate large-scale production; Finally, of course, its price is more suitable, which guarantees that its blessing will not substantially increase the price of mobile phones.
Although iris recognition is far more powerful than fingerprint recognition in terms of security and stability, it has not been popularized in mobile phones so far. The author believes that it is mainly due to the difficulty and price of technology implementation, and of course both. It is complementary.
It is precisely because of the more complex texture of the iris, which also makes the iris recognition technology need to extract more effective unit reading points in the process of realization (as mentioned above, iris recognition generally needs to take 266 units of reading Take points, and other biological identification is generally 13 to 16). This is actually a blade sword. It raises the recognition accuracy rate, and puts forward higher requirements on the complexity of the algorithm and execution efficiency. Said earlier in the software development needs to invest more costs. In addition, on the hardware, it also needs the cooperation of the camera to achieve the iris image acquisition and extraction.
In fact, it is these huge resources invested in hardware and software that make its price advantage in relative fingerprint recognition completely absent. It should be said that the realization of iris recognition technology is not difficult, it is difficult in such a compact mobile phone body Loaded and controlled at a reasonable price range, this is the problem that the industry urgently needs to solve.
Of course, any kind of technology has its limitations, and iris recognition is no exception. First of all, the realization of iris recognition has a certain stress on the light, if the user wears glasses or a beautiful pupil, the iris will be difficult to identify and extract; Second, the recognition and extraction of the iris is also required in the distance, too far or too Nearly all influence.
Bandsaws dedicated to industrial metal-cutting use, such as for structural steel in fabrication shops and for bar stock in machine shops, are available in vertical and horizontal designs. Typical band speeds range from 40 ft/min (0.20 m/s) to 5,000 ft/min (25 m/s), although specialized bandsaws are built for friction cutting of hard metals and run band speeds of 15,000 ft/min (76 m/s). Metal-cutting bandsaws are usually equipped with brushes or brushwheels to prevent chips from becoming stuck in between the blade's teeth. Systems which cool the blade with cutting fluid are also common equipment on metal-cutting bandsaws. The coolant washes away swarf and keeps the blade cool and lubricated.
Horizontal bandsaws hold the workpiece stationary while the blade swings down through the cut. This configuration is used to cut long materials such as pipe or bar stock to length. Thus it is an important part of the facilities in most machine shops. The horizontal design is not useful for cutting curves or complicated shapes. Small horizontal bandsaws typically employ a gravity feed alone, retarded to an adjustable degree by a coil spring; on industrial models, the rate of descent is usually controlled by a hydraulic cylinder that bleeds through an adjustable valve. When the saw is set up for a cut, the operator raises the saw, positions the material to be cut underneath the blade, and then turns on the saw. The blade slowly descends into the material, cutting it as the band blade moves. When the cut is complete, a switch is tripped and the saw automatically turns off. More sophisticated versions of this type of saw are partially or entirely automated (via PLC or CNC) for high-volume cutting of machining blanks. Such machines provide a stream of cutting fluid recirculated from a sump, in the same manner that a CNC machining center does.
A vertical bandsaw, also called a contour saw, keeps the blade's path stationary while the workpiece is moved across it. This type of saw can be used to cut out complex shapes and angles. The part may be fed into the blade manually or with a power assist mechanism. This type of metal-cutting bandsaw is often equipped with a built-in blade welder. This not only allows the operator to repair broken blades or fabricate new blades quickly, but also allows for the blade to be purposely cut, routed through the center of a part, and re-welded in order to make interior cuts. These saws are often fitted with a built-in air blower to cool the blade and to blow chips away from the cut area giving the operator a clear view of the work. This type of saw is also built in a woodworking version. The woodworking type is generally of much lighter construction and does not incorporate a power feed mechanism, coolant, or welder.
Advancements have also been made in the bandsaw blades used to cut metals. Bimetal blades with high speed steel teeth, including cobalt grades, are now the norm. The development of new tooth geometries and tooth pitches has produced increased production rates and greater blade life. New materials and processes such as M51 steel and the cryogenic treatment of blades have produced results that were thought impossible just a few years ago. New machines have been developed to automate the welding process of bandsaw blades as well.
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Jiangsu Hoston Machine Tools Co., Ltd. , https://www.hostoncnc.com