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False Alarms
A false alarm, also called a nuisance alarm, is the deceptive or erroneous report of an emergency, causing unnecessary panic and/or bringing resources (such as emergency services) to a place where they are not needed. False alarms may occur with residential burglary alarms, smoke detectors, industrial alarms, and in signal detection theory. False alarms have the potential to divert emergency responders away from legitimate emergencies, which could ultimately lead to loss of life. In some cases, repeated false alarms in a certain area may cause occupants to develop alarm fatigue and to start ignoring most alarms, knowing that each time it will probably be false. Intentionally falsely activating alarms in businesses and schools can lead to serious disciplinary actions, and criminal penalties such as fines and jail time. Overview The term “false alarm” refers to alarm systems in many different applications being triggered by something other than the expected trigger-event. Exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alarm
An alarm device is a mechanism that gives an audible, visual or other kind of alarm signal to alert someone to a problem or condition that requires urgent attention. Alphabetical musical instruments Etymology The word ''alarm'' comes from the Old French ''a l'arme'' meaning "to the arms", or "to the weapons", telling armed men to pick up their weapons and get ready for action because an enemy may have suddenly appeared. The word ''alarum'' is an archaic form of ''alarm''. It was sometimes used as a call to arms in the stage directions of Elizabethan dramas. The term comes from the Italian ''all'armi'' and appears 89 times in Shakespeare's first folio. Often explained as the off-stage sounds of conflict or disturbance, recent research suggests a bell or drum may have been used to rouse soldiers from sleep. History and development Early alarm devices were often bells, drums, other musical instruments, or any items which made unusual loud noises that attracted the attention o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1983 Soviet Nuclear False Alarm Incident
On 26 September 1983, during the Cold War, the nuclear early-warning radar of the Soviet Union reported the launch of one intercontinental ballistic missile with four more missiles behind it, from bases in the United States. These missile attack warnings were suspected to be false alarms by Stanislav Petrov, an officer of the Soviet Air Defence Forces on duty at the command center of the early-warning system. He decided to wait for corroborating evidence—of which none arrived—rather than immediately relaying the warning up the chain-of-command. This decision is seen as having prevented a retaliatory nuclear attack against the United States and its NATO allies, which would likely have resulted in an escalation to a full-scale nuclear war. Investigation of the satellite warning system later determined that the system had indeed malfunctioned. Background The incident occurred at a time of severely strained relations between the United States and the Soviet Union. Respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burglar Alarm
A security alarm is a system designed to detect intrusion, such as unauthorized entry, into a building or other areas such as a home or school. Security alarms used in residential, commercial, industrial, and military properties protect against burglary (theft) or property damage, as well as personal protection against intruders. Security alerts in neighborhoods show a connection with diminished robbery. Car alarms likewise help protect vehicles and their contents. Prisons also use security systems for the control of inmates. Some alarm systems serve a single purpose of burglary protection; combination systems provide fire and intrusion protection. Intrusion-alarm systems are combined with closed-circuit television surveillance (CCTV) systems to record intruders' activities and interface to access control systems for electrically locked doors. There are many types of security systems. Homeowners typically have small, self-contained noisemakers. These devices can also be complica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2018 Hawaii False Missile Alert
On the morning of Saturday, January 13, 2018, a ballistic missile alert was accidentally issued via the Emergency Alert System and Wireless Emergency Alert System over television, radio and cellphones in the U.S. state of Hawaii. The alert stated that there was an incoming ballistic missile threat inbound to Hawaii, advised residents to seek shelter, before it concluded: "This is not a drill". The message was sent at 8:07 a.m. local time. Civil defense outdoor warning sirens were not authorized by the state. Thirty-eight minutes and 13 seconds later, state officials blamed a miscommunication during a drill at the Hawaii Emergency Management Agency for the first message. Then-Governor David Ige publicly apologized for the erroneous alert. The Federal Communications Commission and the Hawaii House of Representatives launched investigations into the incident, leading to the resignation of the state's emergency management administrator. Background Escalating tensions betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2005 Connecticut False Evacuation Alert
On February 1, 2005, the Emergency Alert System was activated in portions of Connecticut calling for the immediate evacuation of the entire state. The activation was in error. Later studies showed that residents did not evacuate, and that the most common response was to 'change the channel' or seek other confirmation. Background The Emergency Alert System (EAS) is a public warning system in the United States that allows designated government authorities to suspend and preempt terrestrial radio and television broadcasts when needed to issue urgent public safety alerts. The highest priority alert that can be issued is an Emergency Action Notification (EAN), sometimes called a "presidential alert". An EAN sets into motion a series of events that causes all of the United States' television and radio stations to become networked together to simulcast the President of the United States, or another federal official. An Emergency Action Notification has never been used for an actual even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alarm Fatigue
Alarm fatigue or alert fatigue describes how busy workers (in the case of health care, clinicians) become desensitized to safety alerts, and as a result ignore or fail to respond appropriately to such warnings. Alarm fatigue occurs in many fields, including construction and mining (where backup alarms sound so frequently that they often become senseless background noise), healthcare (where electronic monitors tracking clinical information such as vital signs and blood glucose sound alarms so frequently, and often for such minor reasons, that they lose the urgency and attention-grabbing power which they are intended to have), and the nuclear power field. Like crying wolf, such false alarms rob the critical alarms of the importance they deserve. Alarm management and policy are critical to prevent alarm fatigue. Healthcare The constant sounds of alarms and noises from blood pressure machines, ventilators and heart monitors causes a "tuning out" of the sounds due to the brain adj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boland Hall Fire
The Boland Hall fire was a fatal fire in Boland Hall, a freshman residence hall on the Seton Hall University campus in South Orange, New Jersey, United States on January 19, 2000. Three students died and 58 were injured, several with very serious burns. It was one of the deadliest college fires in recent U.S. history. Two students who started the fire as a prank were indicted in mid-2003, reached a plea agreement with prosecutors in late 2006, and were sentenced to five years' imprisonment in early 2007. The Fire The fire began around 4:30 a.m. on January 19, 2000, when most students were asleep. Two students, later identified as Sean Ryan and Joseph LePore, set fire to a paper banner that had been partially torn off from a wall display, located in a third floor lounge. In their account, the two men were intoxicated and decided to set fire to the banner as a prank, which would cause the smoke detectors to go off and the students would evacuate into weather. Ryan lit a match, pas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanislav Petrov
Stanislav Yevgrafovich Petrov (russian: Станисла́в Евгра́фович Петро́в; 7 September 1939 – 19 May 2017) was a lieutenant colonel of the Soviet Air Defence Forces who played a key role in the 1983 Soviet nuclear false alarm incident. On 26 September 1983, three weeks after the Soviet military had shot down Korean Air Lines Flight 007, Petrov was the duty officer at the command center for the Oko nuclear early-warning system when the system reported that a missile had been launched from the United States, followed by up to five more. Petrov judged the reports to be a false alarm. His subsequent decision to disobey orders, against Soviet military protocol, is credited with having prevented an erroneous retaliatory nuclear attack on the United States and its NATO allies that could have resulted in a large-scale nuclear war which could have wiped out half of the population of the countries involved. An investigation later confirmed that the Soviet sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant False Alarm Rate
Constant false alarm rate (CFAR) detection refers to a common form of adaptive algorithm used in radar systems to detect target returns against a background of noise, clutter and interference. Principle In the radar receiver, the returning echoes are typically received by the antenna, amplified, down-converted to an intermediate frequency, and then passed through detector circuitry that extracts the envelope of the signal, known as the ''video signal''. This video signal is proportional to the power of the received echo. It comprises the desired echo signal as well as the unwanted signals from internal receiver noise and external clutter and interference. The term ''video'' refers to the resulting signal being appropriate for display on a cathode ray tube, or "video screen". The role of the constant false alarm rate circuitry is to determine the power threshold above which any return can be considered to probably originate from a target as opposed to one of the spurious sources ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoke Detector
A smoke detector is a device that senses smoke, typically as an indicator of fire. Smoke detectors are usually housed in plastic enclosures, typically shaped like a disk about in diameter and thick, but shape and size vary. Smoke can be detected either optically (photoelectric) or by physical process (ionization). Detectors may use one or both sensing methods. Sensitive alarms can be used to detect and deter smoking in banned areas. Smoke detectors in large commercial and industrial buildings are usually connected to a central fire alarm system. Household smoke detectors, also known as ''smoke alarms'', generally issue an audible or visual alarm from the detector itself or several detectors if there are multiple devices interlinked. Household smoke detectors range from individual battery-powered units to several interlinked units with battery backup. With interlinked units, if any unit detects smoke, alarms will trigger at all of the units. This happens even if household power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detection Theory
Detection theory or signal detection theory is a means to measure the ability to differentiate between information-bearing patterns (called stimulus in living organisms, signal in machines) and random patterns that distract from the information (called noise, consisting of background stimuli and random activity of the detection machine and of the nervous system of the operator). In the field of electronics, signal recovery is the separation of such patterns from a disguising background. According to the theory, there are a number of determiners of how a detecting system will detect a signal, and where its threshold levels will be. The theory can explain how changing the threshold will affect the ability to discern, often exposing how adapted the system is to the task, purpose or goal at which it is aimed. When the detecting system is a human being, characteristics such as experience, expectations, physiological state (e.g., fatigue) and other factors can affect the threshold app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information
Information is an abstract concept that refers to that which has the power to inform. At the most fundamental level information pertains to the interpretation of that which may be sensed. Any natural process that is not completely random, and any observable pattern in any medium can be said to convey some amount of information. Whereas digital signals and other data use discrete signs to convey information, other phenomena and artifacts such as analog signals, poems, pictures, music or other sounds, and currents convey information in a more continuous form. Information is not knowledge itself, but the meaning that may be derived from a representation through interpretation. Information is often processed iteratively: Data available at one step are processed into information to be interpreted and processed at the next step. For example, in written text each symbol or letter conveys information relevant to the word it is part of, each word conveys information rele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
