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Electronic Article Surveillance
Electronic article surveillance is a technological method for preventing shoplifting from retail stores, pilferage of books from libraries or removal of properties from office buildings. Special tags are fixed to merchandise; these tags are removed or deactivated by the clerks when the item is properly bought or checked out. At the exits of the store, a detection system sounds an alarm or otherwise alerts the staff when it senses active tags. Some stores also have detection systems at the entrance to the restrooms that sound an alarm if someone tries to take unpaid merchandise with them into the restroom. For high-value goods that are to be manipulated by the patrons, wired alarm clips called spider wrap may be used instead of tags. History Surveillance tags that could be attached to items in stores were first invented by Arthur Minasy in 1966. Initially the concept of pilferage becoming a real concern to retailers started in 1964 when a requirement was raised by a retailer in Oh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoplifting
Shoplifting is the theft of goods from an open retail establishment, typically by concealing a store item on one's person, in pockets, under clothes or in a bag, and leaving the store without paying. With clothing, shoplifters may put on items from the store and leave the store wearing the clothes. The terms ''shoplifting'' and ''shoplifter'' are not usually defined in law. The crime of shoplifting generally falls under the legal classification of larceny. Shoplifting is distinct from burglary (theft by breaking into a closed store), robbery (stealing by threatening or engaging in violent behavior), or armed robbery (stealing by using a weapon). In the retail industry, the word '' shrinkage'' (or ''shrink'') can be used to refer to merchandise lost by shoplifting, but the word also includes loss by other means, such as waste, uninsured damage to products and theft by store employees. Shoplifters range from amateurs acting on impulse, to career criminals who habitually engage i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Booster Bag
A booster bag is a handmade bag used to shoplift, typically from retail stores, libraries, and any other location employing security detectors to deter theft. The booster bag can be an ordinary shopping bag, backpack, pocketed garment, or other inconspicuous container whose inside is lined with a special material, typically multiple layers of aluminium foil. An item is placed inside the booster bag (effectively a Faraday cage). This provides electromagnetic shielding, with the result that electronic security tags inside the bag may not be detected by security panels in the detector antennas at the store exit. Booster bags have been used by professional shoplifters for several years. Once a bag has been successfully tested, a shoplifter can steal dozens of items with very little effort. However, as electronic article systems improve, shoplifters are turning to high efficiency tag removal devices. The name "booster bag" comes from "boost" in the slang sense of "shoplift." See als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diode
A diode is a two- terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diode vacuum tube or thermionic diode is a vacuum tube with two electrodes, a heated cathode and a plate, in which electrons can flow in only one direction, from cathode to plate. A semiconductor diode, the most commonly used type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals. Semiconductor diodes were the first semiconductor electronic devices. The discovery of asymmetric electrical conduction across the contact between a crystalline mineral and a metal was made by German physicist Ferdinand Braun in 1874. Today, most diodes are made of silicon, but other semiconducting materials such as gallium arsenide and germanium are also used. Among many uses, diodes are found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves ( radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into electrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakdown Voltage
The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to experience electrical breakdown and become electrically conductive. For diodes, the breakdown voltage is the minimum reverse voltage that makes the diode conduct appreciably in reverse. Some devices (such as TRIACs) also have a ''forward breakdown voltage''. Electrical breakdown Materials are often classified as conductors or insulators based on their resistivity. A conductor is a substance which contains many mobile charged particles called charge carriers which are free to move about inside the material. An electric field is created across a piece of the material by applying a voltage difference between electrical contacts on different sides of the material. The force of the field causes the charge carriers within the material to move, creating an electric current from the positive contact to the negative contact. For example, in metals one or more of the negatively charg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electricity and magnetism, two distinct but closely intertwined phenomena. In essence, electric forces occur between any two charged particles, causing an attraction between particles with opposite charges and repulsion between particles with the same charge, while magnetism is an interaction that occurs exclusively between ''moving'' charged particles. These two effects combine to create electromagnetic fields in the vicinity of charge particles, which can exert influence on other particles via the Lorentz force. At high energy, the weak force and electromagnetic force are unified as a single electroweak force. The electromagnetic force is responsible for ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the '' condenser microphone''. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LC Circuit
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together. The circuit can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency. LC circuits are used either for generating signals at a particular frequency, or picking out a signal at a particular frequency from a more complex signal; this function is called a bandpass filter. They are key components in many electronic devices, particularly radio equipment, used in circuits such as oscillators, filters, tuners and frequency mixers. An LC circuit is an idealized model since it assumes there is no dissipation of energy due to resistance. Any practical implementation of an LC circuit will always include loss resulting from small but non-zero resistance within the components an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
304 RF EAS Label
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societies. Evolution of the Arabic digit The use of three lines to denote the number 3 occurred in many writing systems, including some (like Roman and Chinese numerals) that are still in use. That was also the original representation of 3 in the Brahmic (Indian) numerical notation, its earliest forms aligned vertically. However, during the Gupta Empire the sign was modified by the addition of a curve on each line. The Nāgarī script rotated the lines clockwise, so they appeared horizontally, and ended each line with a short downward stroke on the right. In cursive script, the three strokes were eventually connected to form a glyph resembling a with an additional stroke at the bottom: ३. The Indian digits spread to the Caliphate in the 9th c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ws Rfrp
WS, Ws, or ws may refer to: Businesses and organizations * Ware Shoals Railroad (reporting mark WS) * WestJet (IATA airline code WS) * Society of Writers to Her Majesty's Signet, in post-nomial abbreviation * Williams Street, the production arm for Cartoon Network’s nighttime programming block, Adult Swim. * Warm Showers, a non-profit hospitality exchange network for world cyclists. * Williams-Sonoma, Inc., American kitchenware and home furnishings retailer. Places * WS postcode area, West Midlands, UK * Samoa (ISO 3166-1 country code WS) * Winschoten railway station, the Netherlandsm station code Science and technology * .ws, the Internet country code top-level domain for Samoa * ws:// WebSocket protocol prefix in a URI * Watt second (Ws) or Joule, a unit of energy * Web service, software system designed to support machine-to-machine interaction over the Web * Werner syndrome, premature aging * Williams syndrome, a developmental disorder * WonderSwan, handheld game console ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Anisotropy
In condensed matter physics, magnetic anisotropy describes how an object's magnetic properties can be different depending on direction. In the simplest case, there is no preferential direction for an object's magnetic moment. It will respond to an applied magnetic field in the same way, regardless of which direction the field is applied. This is known as magnetic isotropy. In contrast, magnetically anisotropic materials will be easier or harder to magnetize depending on which way the object is rotated. For most magnetically anisotropic materials, there are two easiest directions to magnetize the material, which are a 180° rotation apart. The line parallel to these directions is called the easy axis. In other words, the easy axis is an energetically favorable direction of spontaneous magnetization. Because the two opposite directions along an easy axis are usually equivalently easy to magnetize along, the actual direction of magnetization can just as easily settle into either d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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