Wi-Fi (IPA: /ˈwaɪfaɪ/) is a trademark of the Wi-Fi Alliance, founded in 1999 as Wireless Internet Compatibility Alliance (WICA), comprising more than 300 companies, whose products are certified by the Wi-Fi Alliance, based on the IEEE 802.11 standards (also called Wireless LAN (WLAN) and Wi-Fi). This certification warrants interoperability between different wireless devices.
The alliance was founded because many products did not correctly implement IEEE 802.11 and some included proprietary extensions. This led to incompatibilities between products from different manufacturers.
The Wi-Fi Alliance tests the wireless components to their own terms of reference. Products that pass become Wi-Fi certified and may carry the Wi-Fi logo. Only products of Wi-Fi Members are tested, because they pay membership and per-item fees. Absence of the Wi-Fi logo does not necessarily mean non-compliance with the standard.
In France, Poland, the United States, and some other countries, the term Wi-Fi often is used by the public as a synonym for wireless Internet (WLAN); but not every wireless Internet product has a Wi-Fi certification, which may be because of certification costs that must be paid for each certified device type.
Saturday, March 14, 2009
Keyboard
From mechanical typewriters
* Shift selects the upper character, or select upper case of letters. The Shift key in typewriters was attached to a lever that moved the character types so that the uppercase characters could be printed in the paper. Unlike mechanical typewriters, PC keyboards do not capitalize all letters properly when both shift keys are engaged simultaneously.
* Caps Lock selects upper case, or if shift is pressed, lower case of letters. In mechanical typewriters, it worked like the Shift key, but also used a lock to keep the Shift key depressed. The lock was released by pressing the Shift key.
* Enter wraps to the next line or activates the default or selected option. ASCII keyboards were labeled CR or Return. Typewriters used a lever that would return the cylinder with the paper to the start of the line.
[edit] From Teletype keyboards
* Ctrl shifts the value of letters and numbers from the ASCII graphics range, down into the ASCII control characters. For example, CTRL-S is XOFF (stops many programs as they print to screen) CTRL-Q is XON (resume printing stopped by CTRL-S).
* Esc produces an ASCII escape character. It may be used to exit menus or modes.
* Tab produces an ASCII tab character. Moves to the next tab stop.
* ~ is the tilde, an accent backspaced and printed over other letters for non-English languages. Nowadays the key does not produce a backspaceable character and is used for 'not' or 'circa'.
* ` is a grave accent or backtick, also formerly backspaced over letters to write non-English languages; on some systems it is used as an opening quote. The single quote ' is normally used for an acute accent.
* ^ is a circumflex, another accent for non-English languages. Also used to indicate exponentiation where superscript is not available.
* * is an asterisk, used to indicate a note, or multiplication.
* _ is an underscore, backspaced and overprinted to add emphasis.
* | is a vertical bar, originally used as a typographic separator for optical character recognition. Many character sets break it in the middle so it cannot be confused with the numeral "1" or the letter "l" (in most EBCDIC codepages, vertical bar and divided vertical bar are separate characters). This character is often known as a "pipe" or a "fencepost.
* Shift selects the upper character, or select upper case of letters. The Shift key in typewriters was attached to a lever that moved the character types so that the uppercase characters could be printed in the paper. Unlike mechanical typewriters, PC keyboards do not capitalize all letters properly when both shift keys are engaged simultaneously.
* Caps Lock selects upper case, or if shift is pressed, lower case of letters. In mechanical typewriters, it worked like the Shift key, but also used a lock to keep the Shift key depressed. The lock was released by pressing the Shift key.
* Enter wraps to the next line or activates the default or selected option. ASCII keyboards were labeled CR or Return. Typewriters used a lever that would return the cylinder with the paper to the start of the line.
[edit] From Teletype keyboards
* Ctrl shifts the value of letters and numbers from the ASCII graphics range, down into the ASCII control characters. For example, CTRL-S is XOFF (stops many programs as they print to screen) CTRL-Q is XON (resume printing stopped by CTRL-S).
* Esc produces an ASCII escape character. It may be used to exit menus or modes.
* Tab produces an ASCII tab character. Moves to the next tab stop.
* ~ is the tilde, an accent backspaced and printed over other letters for non-English languages. Nowadays the key does not produce a backspaceable character and is used for 'not' or 'circa'.
* ` is a grave accent or backtick, also formerly backspaced over letters to write non-English languages; on some systems it is used as an opening quote. The single quote ' is normally used for an acute accent.
* ^ is a circumflex, another accent for non-English languages. Also used to indicate exponentiation where superscript is not available.
* * is an asterisk, used to indicate a note, or multiplication.
* _ is an underscore, backspaced and overprinted to add emphasis.
* | is a vertical bar, originally used as a typographic separator for optical character recognition. Many character sets break it in the middle so it cannot be confused with the numeral "1" or the letter "l" (in most EBCDIC codepages, vertical bar and divided vertical bar are separate characters). This character is often known as a "pipe" or a "fencepost.
VCD
Overall picture quality is intended to be comparable to VHS video.[3] Poorly compressed VCD video can sometimes be lower quality than VHS video, but VCD exhibits block artifacts rather than analog noise, and does not deteriorate further with each use.
352x240 (or SIF) resolution was chosen because it is half the vertical, and half the horizontal resolution of NTSC video. 352x288 is similarly one quarter PAL/SECAM resolution. This approximates the (overall) resolution of an analog VHS tape, which, although it has double the number of (vertical) scan lines, has a much lower horizontal resolution.
VCD video is mostly compatible with the DVD-Video standard, except for any video encoded at 23.976 frames per second, which must use 3:2 pulldown.
[edit] Audio
* Codec: MPEG-1 Audio Layer II
* Frequency: 44,100 hertz (44.1 kHz)
* Output: Dual channel or stereo
* Bitrate: 224 kilobits per second
o Rate Control: Constant bitrate
As with most CD-based formats, VCD audio is incompatible with the DVD-Video standard due to a difference in frequency; DVDs require 48 kHz, whereas VCDs use 44.1 kHz.
352x240 (or SIF) resolution was chosen because it is half the vertical, and half the horizontal resolution of NTSC video. 352x288 is similarly one quarter PAL/SECAM resolution. This approximates the (overall) resolution of an analog VHS tape, which, although it has double the number of (vertical) scan lines, has a much lower horizontal resolution.
VCD video is mostly compatible with the DVD-Video standard, except for any video encoded at 23.976 frames per second, which must use 3:2 pulldown.
[edit] Audio
* Codec: MPEG-1 Audio Layer II
* Frequency: 44,100 hertz (44.1 kHz)
* Output: Dual channel or stereo
* Bitrate: 224 kilobits per second
o Rate Control: Constant bitrate
As with most CD-based formats, VCD audio is incompatible with the DVD-Video standard due to a difference in frequency; DVDs require 48 kHz, whereas VCDs use 44.1 kHz.
DVD
DVD, also known as "Digital Versatile Disc" or "Digital Video Disc," is a optical disc storage media format. Its main uses are video and data storage. Most DVDs are of the same dimensions as compact discs (CDs) but store more than six times as much data.
Variations of the term DVD often describe the way data is stored on the discs: DVD-ROM (Read Only Memory), has data that can only be read and not written, DVD-R and DVD+R can record data only once and then function as a DVD-ROM. DVD-RW, DVD+RW and DVD-RAM can both record and erase data multiple times. The wavelength used by standard DVD lasers is 650 nm,[1] and thus the light has a red color.
DVD-Video and DVD-Audio discs respectively refer to properly formatted and structured video and audio content. Other types of DVDs, including those with video content, may be referred to as DVD-Data discs. As next generation high-definition optical formats also use a disc identical in some aspects yet more advanced than a DVD, such as Blu-ray Disc, the original DVD is occasionally given the retronym SD DVD (for standard definition).[2][3]
Variations of the term DVD often describe the way data is stored on the discs: DVD-ROM (Read Only Memory), has data that can only be read and not written, DVD-R and DVD+R can record data only once and then function as a DVD-ROM. DVD-RW, DVD+RW and DVD-RAM can both record and erase data multiple times. The wavelength used by standard DVD lasers is 650 nm,[1] and thus the light has a red color.
DVD-Video and DVD-Audio discs respectively refer to properly formatted and structured video and audio content. Other types of DVDs, including those with video content, may be referred to as DVD-Data discs. As next generation high-definition optical formats also use a disc identical in some aspects yet more advanced than a DVD, such as Blu-ray Disc, the original DVD is occasionally given the retronym SD DVD (for standard definition).[2][3]
Broadband
In telecommunication
Broadband in telecommunications refers to a signaling method that includes or handles a relatively wide range of frequencies, which may be divided into channels or frequency bins. Broadband is always a relative term, understood according to its context. The wider the bandwidth, the greater the information-carrying capacity. In radio, for example, a very narrow-band signal will carry Morse code; a broader band will carry speech; a still broader band is required to carry music without losing the high audio frequencies required for realistic sound reproduction. A television antenna described as "normal" may be capable of receiving a certain range of channels; one described as "broadband" will receive more channels. In data communications an analogue modem will transmit a bandwidth of 56 kilobits per seconds (kbit/s) over a telephone line; over the same telephone line a bandwidth of several megabits per second can be handled by ADSL, which is described as broadband (relative to a modem over a telephone line, although much less than can be achieved over a fibre optic circuit).
[edit] In data communications
Broadband in data can refer to broadband networks or broadband Internet and may have the same meaning as above, so that data transmission over a fiber optic cable would be referred to as broadband as compared to a telephone modem operating at 56,000 bits per second.
However, broadband in data communications is frequently used in a more technical sense to refer to data transmission where multiple pieces of data are sent simultaneously to increase the effective rate of transmission, regardless of data signaling rate. In network engineering this term is used for methods where two or more signals share a medium.[1]
Broadband in telecommunications refers to a signaling method that includes or handles a relatively wide range of frequencies, which may be divided into channels or frequency bins. Broadband is always a relative term, understood according to its context. The wider the bandwidth, the greater the information-carrying capacity. In radio, for example, a very narrow-band signal will carry Morse code; a broader band will carry speech; a still broader band is required to carry music without losing the high audio frequencies required for realistic sound reproduction. A television antenna described as "normal" may be capable of receiving a certain range of channels; one described as "broadband" will receive more channels. In data communications an analogue modem will transmit a bandwidth of 56 kilobits per seconds (kbit/s) over a telephone line; over the same telephone line a bandwidth of several megabits per second can be handled by ADSL, which is described as broadband (relative to a modem over a telephone line, although much less than can be achieved over a fibre optic circuit).
[edit] In data communications
Broadband in data can refer to broadband networks or broadband Internet and may have the same meaning as above, so that data transmission over a fiber optic cable would be referred to as broadband as compared to a telephone modem operating at 56,000 bits per second.
However, broadband in data communications is frequently used in a more technical sense to refer to data transmission where multiple pieces of data are sent simultaneously to increase the effective rate of transmission, regardless of data signaling rate. In network engineering this term is used for methods where two or more signals share a medium.[1]
Handphone
A mobile phone (also known as a handphone,[1] wireless phone, cell phone, cellular phone, cellular telephone or cell telephone) is a long-range, electronic device used for mobile voice or data communication over a network of specialized base stations known as cell sites. In addition to the standard voice function of a mobile phone, telephone, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video, MP3 player, radio and GPS. Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception is satellite phones).
A mobile phone proper typically has a telephone keypad, more advanced devices have a separate key for each letter. Some mobile phones have a touchscreen.
A mobile phone proper typically has a telephone keypad, more advanced devices have a separate key for each letter. Some mobile phones have a touchscreen.
Remote
A remote control is an electronic device used for the remote operation of a machine.
The term remote control can be contracted to remote or controller. It is known by many other names as well, such as clicker and also the changer. It however, is also known as the button, mainly in North England[citation needed]. Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems and DVD players. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. The codes can be copied onto another device, and it this principle that is used in the TV Silencer, where the code for mute is copied and then replayed automatically whenever the telephone rings. They are usually powered by small AAA or AA size batteries.
The term remote control can be contracted to remote or controller. It is known by many other names as well, such as clicker and also the changer. It however, is also known as the button, mainly in North England[citation needed]. Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems and DVD players. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. The codes can be copied onto another device, and it this principle that is used in the TV Silencer, where the code for mute is copied and then replayed automatically whenever the telephone rings. They are usually powered by small AAA or AA size batteries.
Printer
In computing, a printer is a peripheral which produces a hard copy (permanent human-readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most newer printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces (typically wireless or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time.
In addition, a few modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanners and/or fax machines in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called Multifunction Printers (MFP), Multi-Function Devices (MFD), or All-In-One (AIO) printers. Most MFPs include printing, scanning, and copying among their features. A Virtual printer is a piece of computer software whose user interface and API resemble that of a printer driver, but which is not connected with a physical computer printer.
Printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. The printing press remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.[1]
In addition, a few modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanners and/or fax machines in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called Multifunction Printers (MFP), Multi-Function Devices (MFD), or All-In-One (AIO) printers. Most MFPs include printing, scanning, and copying among their features. A Virtual printer is a piece of computer software whose user interface and API resemble that of a printer driver, but which is not connected with a physical computer printer.
Printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. The printing press remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.[1]
Computer
A computer is a machine that manipulates data according to a list of instructions.
The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC).[1] Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.
The ability to store and execute lists of instructions called programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks given enough time and storage capacity.
The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC).[1] Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.
The ability to store and execute lists of instructions called programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks given enough time and storage capacity.
Canon
History
‘Precision Optical Instruments Laboratory’ is the predecessor of Canon Inc. and was founded in Tokyo in 1937 by Takeshi Mitarai, Goro Toshida, Saburo Uchida and Takeo Maeda.
1934 logo depicting the Bodhisattva Kwan'on
1930s - 60s 1934: ‘The Kwanon’[3], Japan’s first 35 mm focal plane-shutter camera, was produced in prototype form. 1940: An indirect X-ray camera, also a first for Japan, is developed. 1947: The company is renamed Canon Camera Co., Inc. 1958: A field zoom lens for television broadcasting is introduced. 1959: The world’s first camcorder with a zoom lens, ‘Relfex Zoom 8’, is introduced. 1964: ‘Canola 130’, the world’s first 10-key calculator is introduced. 1969: The company’s name is changed to Canon Inc.
1970s – 00s 1971: The ‘Canon F-1’, a top-end SLR (Single Lens Reflex) camera, and FD lenses are introduced. 1976: Canon launches the world’s first camera with an embedded micro-computer, the ‘AE-1’. 1985: The world’s first Ink Jet printer using Bubble Jet technology is introduced. 1987: The 'EOS 650' autofocus SLR camera is introduced and the Canon Foundation is established. 1988: Canon introduces 'Kyosei philosophy'. 1992: The ‘EOS-5’, the first-ever camera with eye-controlled autofocus is launched. 1995: The IXUS, a pocket-sized camera with the Advanced Photo System, is introduced. 1995: introduced the first commercially available SLR lens with internal image stabilization, the Canon EF75-300mm f/4-5.6 IS USM. 1997: Canon enters the digital video camcorder market. 2002: Mr Fujio Mitarai, President and CEO of Canon Inc., is named one of the world’s top 25 managers by magazine BusinessWeek. 2003: The world’s first portable digital X-ray system is used to reconstruct the face of an Egyptian mummy believed to be Queen Nefertiti. 2004: The XEED SX50 LCD projector is introduced. 2005: Canon’s first high-definition video camcorder is introduced. 2007: Canon Europe’s 50th anniversary.
Today, the company produces digital compact and SLR cameras, printers and analog and digital copiers for the office, including its line of imageRUNNER and imagePRESS digital multifunctional devices.
In 2008 Canon was awarded over 2000 patents in the U.S.; it regularly places in the top five in total patents for the year.
‘Precision Optical Instruments Laboratory’ is the predecessor of Canon Inc. and was founded in Tokyo in 1937 by Takeshi Mitarai, Goro Toshida, Saburo Uchida and Takeo Maeda.
1934 logo depicting the Bodhisattva Kwan'on
1930s - 60s 1934: ‘The Kwanon’[3], Japan’s first 35 mm focal plane-shutter camera, was produced in prototype form. 1940: An indirect X-ray camera, also a first for Japan, is developed. 1947: The company is renamed Canon Camera Co., Inc. 1958: A field zoom lens for television broadcasting is introduced. 1959: The world’s first camcorder with a zoom lens, ‘Relfex Zoom 8’, is introduced. 1964: ‘Canola 130’, the world’s first 10-key calculator is introduced. 1969: The company’s name is changed to Canon Inc.
1970s – 00s 1971: The ‘Canon F-1’, a top-end SLR (Single Lens Reflex) camera, and FD lenses are introduced. 1976: Canon launches the world’s first camera with an embedded micro-computer, the ‘AE-1’. 1985: The world’s first Ink Jet printer using Bubble Jet technology is introduced. 1987: The 'EOS 650' autofocus SLR camera is introduced and the Canon Foundation is established. 1988: Canon introduces 'Kyosei philosophy'. 1992: The ‘EOS-5’, the first-ever camera with eye-controlled autofocus is launched. 1995: The IXUS, a pocket-sized camera with the Advanced Photo System, is introduced. 1995: introduced the first commercially available SLR lens with internal image stabilization, the Canon EF75-300mm f/4-5.6 IS USM. 1997: Canon enters the digital video camcorder market. 2002: Mr Fujio Mitarai, President and CEO of Canon Inc., is named one of the world’s top 25 managers by magazine BusinessWeek. 2003: The world’s first portable digital X-ray system is used to reconstruct the face of an Egyptian mummy believed to be Queen Nefertiti. 2004: The XEED SX50 LCD projector is introduced. 2005: Canon’s first high-definition video camcorder is introduced. 2007: Canon Europe’s 50th anniversary.
Today, the company produces digital compact and SLR cameras, printers and analog and digital copiers for the office, including its line of imageRUNNER and imagePRESS digital multifunctional devices.
In 2008 Canon was awarded over 2000 patents in the U.S.; it regularly places in the top five in total patents for the year.
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