Bande passanteEn électronique, la bande passante d'un système est l'intervalle de fréquences dans lequel l'affaiblissement du signal est inférieur à une valeur spécifiée. C'est une façon sommaire de caractériser la fonction de transfert d'un système, pour indiquer la gamme de fréquences qu'un système peut raisonnablement traiter. Il faut distinguer la bande passante de la largeur de bande, d'une définition plus générale et qui concerne aussi bien les systèmes que les signaux.
Silicon photonicsSilicon photonics is the study and application of photonic systems which use silicon as an optical medium. The silicon is usually patterned with sub-micrometre precision, into microphotonic components. These operate in the infrared, most commonly at the 1.55 micrometre wavelength used by most fiber optic telecommunication systems. The silicon typically lies on top of a layer of silica in what (by analogy with a similar construction in microelectronics) is known as silicon on insulator (SOI).
Quantization (image processing)Quantization, involved in , is a lossy compression technique achieved by compressing a range of values to a single quantum (discrete) value. When the number of discrete symbols in a given stream is reduced, the stream becomes more compressible. For example, reducing the number of colors required to represent a digital makes it possible to reduce its file size. Specific applications include DCT data quantization in JPEG and DWT data quantization in JPEG 2000.
Disque compactUn disque compact, le plus souvent désigné par son sigle anglais CD – abréviation de Compact Disc – est un disque optique utilisé pour stocker des données sous forme numérique. Le Compact Disc a été développé par Sony et Philips et commercialisé à partir de décembre 1982 (mars 1983 en France). Au début des années 1990, il se démocratise, et petit à petit, finit par remplacer les supports analogiques (disque microsillon, cassette audio). vignette|Creux sur la surface d'un CD vu au microscope à balayage.
Silicium-germaniumLes alliages silicium-germanium forment une famille de composés de formule GexSi1-x, utilisés en tant que semi-conducteurs dans des transistors. Ces alliages possèdent également de bonnes caractéristiques thermoélectriques aux hautes températures (au-dessus de ) et sont notamment utilisés pour la génération d’électricité dans le domaine spatial. Ce sont par exemple des alliages de ce type qui sont utilisés pour l' des sondes Voyager. Transistor Thermoélectricité Catégorie:Composé du silicium Catégorie:Comp
Crystalline siliconCrystalline silicon or (c-Si) Is the crystalline forms of silicon, either polycrystalline silicon (poly-Si, consisting of small crystals), or monocrystalline silicon (mono-Si, a continuous crystal). Crystalline silicon is the dominant semiconducting material used in photovoltaic technology for the production of solar cells. These cells are assembled into solar panels as part of a photovoltaic system to generate solar power from sunlight. In electronics, crystalline silicon is typically the monocrystalline form of silicon, and is used for producing microchips.
Soft errorIn electronics and computing, a soft error is a type of error where a signal or datum is wrong. Errors may be caused by a defect, usually understood either to be a mistake in design or construction, or a broken component. A soft error is also a signal or datum which is wrong, but is not assumed to imply such a mistake or breakage. After observing a soft error, there is no implication that the system is any less reliable than before. One cause of soft errors is single event upsets from cosmic rays.
Bandwidth-delay productIn data communications, the bandwidth-delay product is the product of a data link's capacity (in bits per second) and its round-trip delay time (in seconds). The result, an amount of data measured in bits (or bytes), is equivalent to the maximum amount of data on the network circuit at any given time, i.e., data that has been transmitted but not yet acknowledged. The bandwidth-delay product was originally proposed as a rule of thumb for sizing router buffers in conjunction with congestion avoidance algorithm random early detection (RED).
Spectral leakageThe Fourier transform of a function of time, s(t), is a complex-valued function of frequency, S(f), often referred to as a frequency spectrum. Any linear time-invariant operation on s(t) produces a new spectrum of the form H(f)•S(f), which changes the relative magnitudes and/or angles (phase) of the non-zero values of S(f). Any other type of operation creates new frequency components that may be referred to as spectral leakage in the broadest sense. Sampling, for instance, produces leakage, which we call aliases of the original spectral component.
Cost-effectiveness analysisCost-effectiveness analysis (CEA) is a form of economic analysis that compares the relative costs and outcomes (effects) of different courses of action. Cost-effectiveness analysis is distinct from cost–benefit analysis, which assigns a monetary value to the measure of effect. Cost-effectiveness analysis is often used in the field of health services, where it may be inappropriate to monetize health effect.
