event detection
121Railway signalling — Not to be confused with Railway signal. A gantry of British semaphore signals seen from the cab of a steam locomotive Railway signalling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Being… …
122History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
123Planetary defense — Planetary defense, is the concept of protecting Earth (or another planet) from extraterrestrial threats such as near Earth objects or alien invasions.Mitigation of near Earth objectsNear Earth objects (NEOs) are asteroids, comets and large… …
124Human cognitive reliability correlation — (HCR) is a technique used in the field of Human reliability Assessment (HRA), for the purposes of evaluating the probability of a human error occurring throughout the completion of a specific task. From such analyses measures can then be taken to …
125Paradoxe de Fermi — Pour les articles homonymes, voir Fermi. Le radiotélescope Very Large Array dans le Nouveau Mexique (États Unis), haut lieu du …
126Trou noir — Pour les articles homonymes, voir Trou noir (homonymie). En astrophysique, un trou noir est un corps dont le champ gravitationnel est si intense qu’il empêche toute forme de matière ou de rayonnement de s’en échapper (à l exception notable de la… …
127police — /peuh lees /, n., v., policed, policing. n. 1. Also called police force. an organized civil force for maintaining order, preventing and detecting crime, and enforcing the laws. 2. (used with a pl. v.) members of such a force: Several police are… …
128star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
