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Traffic Signal Preemption
Traffic signal preemption (also called traffic signal prioritisation) is a system that allows an operator to override the normal operation of traffic lights. The most common use of these systems manipulates traffic signals in the path of an emergency vehicle, halting conflicting traffic and allowing the emergency vehicle right-of-way, thereby reducing Emergency service#Response time, response times and enhancing traffic safety. Signal preemption can also be used on tram, light rail, light-rail and bus rapid transit systems, to allow public transportation priority access through intersections, and by level crossing, railroad systems at crossings to prevent collisions. Implementation Traffic preemption is implemented in a variety of ways. Traffic light activation devices can be installed on road vehicles, integrated with transport network management systems, or operated by remote control from a fixed location, such as a fire station, or by an Dispatcher#Emergency dispatchers, emerge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Light
Traffic lights, traffic signals, or stoplights – also known as robots in South Africa, Zambia, and Namibia – are signaling devices positioned at intersection (road), road intersections, pedestrian crossings, and other locations in order to control the flow of traffic. Traffic lights usually consist of three signals, transmitting meaningful information to road users through colours and symbols, including arrows and bicycles. The usual traffic light colours are red to stop traffic, Amber (color), amber for traffic change, and green to allow traffic to proceed. These are arranged vertically or horizontally in that order. Although this is internationally standardised, variations in traffic light sequences and laws exist on national and local scales. Traffic lights were first introduced in December 1868 on Parliament Square in London to reduce the need for police officers to control traffic. Since then, electricity and computerised control have advanced traffic light technolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downtown
''Downtown'' is a term primarily used in American and Canadian English to refer to a city's sometimes commercial, cultural and often the historical, political, and geographic heart. It is often synonymous with its central business district (CBD). It may also be a center for shopping and entertainment. Downtowns typically contain a small percentage of a city's employment but are concentrated in services, including high-end services (office or white-collar jobs). Sometimes, smaller downtowns include lower population densities and nearby lower incomes than suburbs. It is often distinguished as a hub of public transit and culture. History Origins The ''Oxford English Dictionarys first citation for "down town" or "downtown" dates to 1770, in reference to the center of Boston. Some have posited that the term "downtown" was coined in New York City, where it was in use by the 1830s to refer to the original settlement, or town, at the southern tip of the island of Manhattan.Fogels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millersville Opticom
Millersville may refer to: * Millersville, Illinois * A former settlement on Jarvis Island in the Pacific Ocean called Millersville, Jarvis Island * Millersville, Maryland * Millersville, Michigan * Millersville, Missouri * Millersville, Ohio * Millersville, Pennsylvania Millersville is a borough in Lancaster County, Pennsylvania, United States. At the 2020 census, the population was 7,629 and in 2021 it was estimated at 7,593. Millersville is home to Millersville University of Pennsylvania. History Origina ... * Millersville, Tennessee * Millersville University of Pennsylvania, a public university {{place name disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receiver (radio)
In radio, radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna (radio), antenna. The antenna intercepts radio waves (electromagnetic waves of radio frequency) and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation. Radio receivers are essential components of all systems based on radio technology. The information produced by the receiver may be in the form of sound, video (television), or digital signal, digital data. A radio receiver may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strobe Light
A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope. The word originated from the Ancient Greek ('), meaning "act of whirling". A typical commercial strobe light has a flash energy in the region of 10 to 150 joules, and discharge times as short as a few milliseconds, often resulting in a flash power of several kilowatts. Larger strobe lights can be used in “continuous” mode, producing extremely intense illumination. The light source is commonly a xenon flash lamp, or ''flashtube'', which has a complex spectrum and a color temperature of approximately 5,600 kelvins. To obtain colored light, colored gels may be used. Scientific explanation of flashtubes Strobe lights usually use flashtubes with energy supplied from a capacitor, an energy storage device much like a battery, but capable of charging and releasing energy much faster. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose level (logarithmic quantity), levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 101/20 (approximately ). The strict original usage above only expresses a relative change. However, the word decibel has since also been used for expressing an Absolute scale, absolute value that is relative to some fixed reference value, in which case the dB symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is "#Voltage, V" (e.g., "20 dBV"). As it originated from a need to express power ratios, two principal types of scaling of the decibel are used to provide consistency depending on whether the scaling refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphone
A microphone, colloquially called a mic (), or mike, is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, and radio and television broadcasting. They are also used in computers and other electronic devices, such as mobile phones, for recording sounds, speech recognition, Voice over IP, VoIP, and other purposes, such as Ultrasonic transducer, ultrasonic sensors or knock sensors. Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; the condenser microphone, which uses the vibrating Diaphragm (acoustics), diaphragm as a capacitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hillsboro, Oregon
Hillsboro ( ) is a city in the U.S. state of Oregon and is the county seat of Washington County, Oregon, Washington County. Situated in the Tualatin Valley on the west side of the Portland metropolitan area, the city hosts many High tech, high-technology companies, such as Intel, locally known as the Silicon Forest. The population was 106,447 at the 2020 United States census, 2020 census, making Hillsboro the List of cities in Oregon, fifth-most populous city in Oregon. Settlers founded a community here in 1842, later named after David Hill (Oregon politician), David Hill, an Oregon politician. Transportation by riverboat on the Tualatin River was part of Hillsboro's settler economy. A railroad reached the area in the early 1870s and an interurban electric railway about four decades later. These railways, as well as highways, aided the slow growth of the city to about 2,000 people by 1910 and about 5,000 by 1950, before the arrival of high-tech companies in the 1980s. Hillsboro h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Engine
A fire engine or fire truck (also spelled firetruck) is a vehicle, usually a specially designed or modified truck, that functions as a firefighting apparatus. The primary purposes of a fire engine include transporting firefighters and water to an incident as well as carrying equipment for firefighting operations in a fire drill. Some fire engines have specialized functions, such as wildfire suppression and aircraft rescue and firefighting, and may also carry equipment for technical rescue. Many fire engines are based on a commercial vehicle chassis that is further upgraded and customized for firefighting requirements. They are generally considered Emergency vehicle, emergency vehicles authorized to be Emergency vehicle equipment, equipped with Emergency vehicle lighting, emergency lights and Siren (alarm), sirens, as well as communication equipment such as two-way radios and mobile computer technology. The terms ''fire engine'' and ''fire truck'' are often used interchangeably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LED Light Bulb
An LED lamp or LED light is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more Electrical efficiency, energy-efficient than equivalent Incandescent light bulb, incandescent lamps and fluorescent lamps. The most efficient commercially available LED lamps have efficiencies exceeding 200 lumen (unit), lumens per watt (lm/W) and convert more than half the input power into light. Commercial LED lamps have a lifespan several times longer than both incandescent and fluorescent lamps. LED lamps require an electronic LED circuit to operate from mains power lines, and losses from this circuit means that the efficiency of the lamp is lower than the efficiency of the LED chips it uses. The driver circuit may require special features to be compatible with lamp dimmers intended for use on incandescent lamps. Generally the current waveform contains some amount of distortion, depending on the luminaires' technology. The LED lamp marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
