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Voiceless bilabial fricative

The voiceless bilabial fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɸ⟩. Features of the voiceless bilabial fricative: Its manner of articulation is fricative, which means it is produced by constricting air flow through a narrow channel at the place of articulation, causing turbulence, its place of articulation is bilabial. Its phonation is voiceless. In some languages the vocal cords are separated, so it is always voiceless, it is an oral consonant. Because the sound is not produced with airflow over the tongue, the central–lateral dichotomy does not apply; the airstream mechanism is pulmonic, which means it is articulated by pushing air with the lungs and diaphragm, as in most sounds. Index of phonetics articles List of languages with on PHOIBLE

Optical mouse

An optical mouse is a computer mouse which uses a light source a light-emitting diode, a light detector, such as an array of photodiodes, to detect movement relative to a surface. Variations of the optical mouse have replaced the older mechanical mouse design, which uses moving parts to sense motion; the earliest optical mice detected movement on pre-printed mousepad surfaces. Modern optical mice work on most opaque diffusely reflective surfaces like paper, but most of them do not work properly on specularly reflective surfaces like polished stone or transparent surfaces like glass. Optical mice that use dark field illumination can function reliably on such surfaces. Though not referred to as optical mice, nearly all mechanical mice tracked movement using LEDs and photodiodes to detect when beams of infrared light did and didn't pass through holes in an incremental rotary encoder wheel. Thus, the primary distinction of “optical mice” is not their use of optics, but their complete lack of moving parts to track mouse movement, instead employing an solid-state system.

The first two optical mice, first demonstrated by two independent inventors in December 1980, had different basic designs: One of these, invented by Steve Kirsch of MIT and Mouse Systems Corporation, used an infrared LED and a four-quadrant infrared sensor to detect grid lines printed with infrared absorbing ink on a special metallic surface. Predictive algorithms in the CPU of the mouse calculated the direction over the grid; the other type, invented by Richard F. Lyon of Xerox, used a 16-pixel visible-light image sensor with integrated motion detection on the same n‑type MOS integrated circuit chip, tracked the motion of light dots in a dark field of a printed paper or similar mouse pad; the Kirsch and Lyon mouse types had different behaviors, as the Kirsch mouse used an x-y coordinate system embedded in the pad, would not work when the pad was rotated, while the Lyon mouse used the x-y coordinate system of the mouse body, as mechanical mice do. The optical mouse sold with the Xerox STAR office computer used an inverted sensor chip packaging approach patented by Lisa M. Williams and Robert S. Cherry of the Xerox Microelectronics Center.

Modern surface-independent optical mice work by using an optoelectronic sensor to take successive images of the surface on which the mouse operates. As computing power grew cheaper, it became possible to embed more powerful special-purpose image-processing chips in the mouse itself; this advance enabled the mouse to detect relative motion on a wide variety of surfaces, translating the movement of the mouse into the movement of the cursor and eliminating the need for a special mouse-pad. A surface-independent coherent light optical mouse design was patented by Stephen B. Jackson at Xerox in 1988; the first commercially available, modern optical computer mice were the Microsoft IntelliMouse with IntelliEye and IntelliMouse Explorer, introduced in 1999 using technology developed by Hewlett-Packard. It worked on any surface, represented a welcome improvement over mechanical mice, which would pick up dirt, track capriciously, invite rough handling, need to be taken apart and cleaned frequently. Other manufacturers soon followed Microsoft's lead using components manufactured by the HP spin-off Agilent Technologies, over the next several years mechanical mice became obsolete.

The technology underlying the modern optical computer mouse is known as digital image correlation, a technology pioneered by the defense industry for tracking military targets. A simple binary-image version of digital image correlation was used in the 1980 Lyon optical mouse. Optical mice use image sensors to image occurring texture in materials such as wood, mouse pads and Formica; these surfaces, when lit at a grazing angle by a light emitting diode, cast distinct shadows that resemble a hilly terrain lit at sunset. Images of these surfaces are captured in continuous succession and compared with each other to determine how far the mouse has moved. To understand how optical flow is used in optical mice, imagine two photographs of the same object except offset from each other. Place both photographs on a light table to make them transparent, slide one across the other until their images line up; the amount that the edges of one photograph overhang the other represents the offset between the images, in the case of an optical computer mouse the distance it has moved.

Optical mice capture more per second. Depending on how fast the mouse is moving, each image will be offset from the previous one by a fraction of a pixel or as many as several pixels. Optical mice mathematically process these images using cross correlation to calculate how much each successive image is offset from the previous one. An optical mouse might use an image sensor having an 18 × 18 pixel array of monochromatic pixels, its sensor would share the same ASIC as that used for storing and processing the images. One refinement would be accelerating the correlation process by using information from previous motions, another refinement would be preventing deadbands when moving by adding interpolation or frame-skipping; the development of the modern optical mouse at Hewlett-Packard Co. was supported by a succession of related projects during the 1990s at HP Laboratories. In 1992 William Holland was awarded US Patent 5,089,712 and John Ertel, William Holland, Kent Vincent, Rueiming Jamp, Richard Baldwin were awarded US Patent 5,149,980 for measuring linear paper advance in a printer by correlating images of paper fibers.

Ross R. Allen, David Beard, Mark T. Smith, Barclay J. Tullis were award

James Stewart Jr.

James Stewart Jr. known as Bubba Stewart, is an American former professional motocross racer who competed in the AMA Motocross and the AMA Supercross Championships. Through his years of racing, he earned the nickname “The Fastest Man on The Planet”, due to his extraordinary talent, speed and innovation. In 2008 James won every moto of the AMA Motocross season; the only other person to do this is Ricky Carmichael. James is second in all time 450 Supercross wins, second all time in AMA outdoor national wins, he is known for innovating the "Bubba Scrub" or just "scrub", which revolutionized the sport and became a fundamental skill needed to compete in Professional Motocross. He was the first to host his own television show "Bubba's World" which brought more attention to the sport, he is arguably the most financially lucrative racer, bringing in endorsement deals paying him over $10M a year throughout his career. Known for his vibrant personality and big smile, James has been featured in news outlets like Rolling Stone, The New York Times, Maxim, ESPN The Magazine, GQ and many more.

Additionally, Teen People named him one of “20 Teens Who Will Change the World”. He has the record for best rookie season, having won 10/12 Motocross races in 2002. James has 5 FIM World Champion titles from Motocross of Nations, World Supercross. 4 AMA Supercross Champion titles, 3 AMA Motocross Champion titles. He won the Redbull Straight Rhythm in both 2014 and 2015. He's a Motocross legend. Stewart was born in Bartow and resides in Haine City Lake Hamilton, Florida, his father, James Sr. was a motocross enthusiast and introduced his son to the sport at the age of three. Stewart entered his first motocross race. Having 84 amateur wins and 7 Loretta Lynn's Amateur Championships all before the age of 16, he debuted as pro in 2002. While crashes and rookie mistakes kept him from winning the 2002 125 West Supercross title, he finished 2nd overall, he went on to dominate the 2002 Motocross Championship, was named the 2002 AMA Rookie of the Year. He was named one of "20 Teens Who Will Change the World" in the April 2003 issue of Teen People magazine.

Stewart went on to win the 2003 125 West Supercross Championship and the 125 East/West Shootout in Las Vegas, Nevada. In 2004 he won both the 125 East Supercross title and the 125 Outdoor national title, only losing one moto to Mike Brown in the latter due to a broken clutch cover. 1 of 2 riders in history to win every moto/race in season Ranked # 2. Ranked #3 all time pro AMA wins. X games medal for best whip. 2002 AMA 125 Motocross national champion. 2003 AMA 125 West Supercross Champion. 2004 AMA 125 East Supercross Champion. 2004 AMA 125 Motocross National Champion. 2006 FIM World Supercross Grand Prix Champion. 2006 Motocross of Nations Champion. 2007 AMA Supercross Champion. 2007 FIM World Supercross Grand Prix Champion. 2008 AMA Motocross National Champion. 2008 Motocross of Nations Champion. 2009 AMA Supercross Champion. 2009 FIM World Supercross Champion. 2014 Redbull Straight Rhythm Champion. 2015 Redbull Straight Rhythm Champion On April 2, 2005, at Texas Stadium, Stewart captured his first Supercross victory.

He would go on to record many more victories throughout 2005 and 2006, he won the 2007 Supercross Championship. He was unable to finish the 2007 National series due to a knee injury. Stewart missed the last 15 races of the 2008 Supercross season due to a knee injury caused by a crash into Dale White #7. Stewart signed with L&M Yamaha racing for the 2009 season, replacing Chad Reed for the supercross season. In the latter season Stewart and Chad Reed were involved in the tightest points race of Stewart's career. Stewart won 11 of the 17 events. On May 2, 2009, at Sam Boyd Stadium in Las Vegas, Stewart won the 2009 Supercross Championship by a margin of 4 points over Reed. After a strong charge by Supercross class rookie Ryan Dungey at the opening round at Anaheim, Stewart captured the lead on lap 18, going on to take the win. In round 2, Stewart was involved in a crash during his heat, but came back to win the Last Chance Qualifier. In the final, a collision with Chad Reed caused both riders to fall.

Reed's left hand was pinned under Stewart and Reed pushed Stewart's head off his arm, in what some deemed to be a physically aggressive manner. Controversy followed in the pits when Stewart pushed Reed's bike off its stand, resulting in an official warning from the AMA. Still struggling with injury Stewart finished 3rd behind Ryan Dungey and Josh Hill in round 3. Stewart retired from the season after having surgery from Dr. Arthur Ting for a broken right scaphoid. Stewart's wrist injury took longer than expected to heal, leaving him out of the 2010 Motocross series, although he did return for one round at Unadilla where he placed third in the first moto and retired early from the second moto, citing bike setup issues and exhaustion. On January 8, 2011 Stewart made his return to Supercross placing 3rd in the Anaheim season opener; the next week at Phoenix on January 15, he won his first main event in over a year, leading all 20 laps over Ryan Villopoto, who trailed close behind for most of the race.

Throughout the season Stewart suffered several crashes with his last big crash in the season finale at Las Vegas where he had the lead but crashed in the whoops. He took out Kevin Windham along with him, allowing Villopoto and Reed to pass On March 10, 2012 Stewart claimed his 44th Supercross win by taking 1st place at Daytona International Speedway. At the end of the season, Stewart left Joe Gibbs Mot