Ethernet over twisted pairEthernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers. Early Ethernet used various grades of coaxial cable, but in 1984, StarLAN showed the potential of simple unshielded twisted pair. This led to the development of 10BASE-T and its successors 100BASE-TX, 1000BASE-T and 10GBASE-T, supporting speeds of 10 and 100 megabit per second, then 1 and 10 gigabit per second respectively.
Opéravignette|Carmen avec Magdalena Kožená et Jonas Kaufmann, Festival de Salzbourg, 2012. vignette|Annonce de la première de Don Juan de Mozart. vignette|La Bohème de Puccini, l'un des opéras les plus joués. Dans la musique occidentale, un opéra est une œuvre musicale et théâtrale pour un orchestre et des chanteurs. L'opéra est l’une des formes de l'art lyrique du théâtre musical occidental.
Broadband Integrated Services Digital NetworkIn the 1980s, the telecommunications industry expected that digital services would follow much the same pattern as voice services did on the public switched telephone network, and conceived an end-to-end circuit switched service, known as Broadband Integrated Services Digital Network (B-ISDN). Before B-ISDN, the original ISDN attempted to substitute the analog telephone system with a digital system which was appropriate for both voice and non-voice traffic.
Câble catégorie 5thumb|upright|Câble Cat 5 équipé de connecteurs RJ45. Le câble catégorie 5 (ou Cat 5) sert de moyen de liaison pour la transmission de données à des débits allant de 10 à 100 Mbit/s (Fast Ethernet) et pour sa variante Cat 5e (Gigabit Ethernet). Il est largement employé dans le câblage de réseaux informatiques utilisant à la fois une topologie en étoile et la technologie Ethernet. thumb|upright|Prise murale permettant une connexion avec du câble Cat 5 ou Cat 5e.
Conformance testingConformance testing — an element of conformity assessment, and also known as compliance testing, or type testing — is testing or other activities that determine whether a process, product, or service complies with the requirements of a specification, technical standard, contract, or regulation. Testing is often either logical testing or physical testing. The test procedures may involve other criteria from mathematical testing or chemical testing. Beyond simple conformance, other requirements for efficiency, interoperability or compliance may apply.
Ghosting (television)In television, a ghost is a replica of the transmitted image, offset in position, that is superimposed on top of the main image. It is often caused when a TV signal travels by two different paths to a receiving antenna, with a slight difference in timing. Common causes of ghosts (in the more specific sense) are: Mismatched impedance along the communication channel, which causes unwanted reflections. The technical term for this phenomenon is ringing.
Electrical terminationIn electronics, electrical termination is the practice of ending a transmission line with a device that matches the characteristic impedance of the line. Termination prevents signals from reflecting off the end of the transmission line. Reflections at the ends of unterminated transmission lines cause distortion, which can produce ambiguous digital signal levels and misoperation of digital systems. Reflections in analog signal systems cause such effects as video ghosting, or power loss in radio transmitter transmission lines.
Primary line constantsThe primary line constants are parameters that describe the characteristics of conductive transmission lines, such as pairs of copper wires, in terms of the physical electrical properties of the line. The primary line constants are only relevant to transmission lines and are to be contrasted with the secondary line constants, which can be derived from them, and are more generally applicable. The secondary line constants can be used, for instance, to compare the characteristics of a waveguide to a copper line, whereas the primary constants have no meaning for a waveguide.
Metropolitan OperaLe Metropolitan Opera ou le « Met » est une salle d'opéra située dans le centre culturel du Lincoln Center, dans l'arrondissement de Manhattan à New York, aux États-Unis. vignette|left|L'ancien opéra de New York sur Broadway, en 1905. Le premier bâtiment, conçu par J. Cleaveland Cady, à l'initiative de riches familles new-yorkaises insatisfaites de ne pas avoir de place à "l'Academy of Music" sur la 14ème rue, est inauguré le . L'opéra Faust de Gounod est joué lors de cette inauguration, avec (Faust), Christine Nilsson (Marguerite) et Sofia Scalchi (Siebel).
Frequency compensationIn electronics engineering, frequency compensation is a technique used in amplifiers, and especially in amplifiers employing negative feedback. It usually has two primary goals: To avoid the unintentional creation of positive feedback, which will cause the amplifier to oscillate, and to control overshoot and ringing in the amplifier's step response. It is also used extensively to improve the bandwidth of single pole systems.
