Glossary of the key notions in Bionics and beyond
Yüklə 295,25 Kb.
|
Valence electron → Valence electrons are the electrons orbiting the outermost shell of the atom are weakly held by the positive proton charges and can be transferred to or shared with one or more other atoms. Valence electrons are bound until they are freed by some outside force or reaction. Validation set → Traning samples for verifying and avoiding overtraninig. For each sample the empirical error is computed during the learning procedure. Value → The process of measurement yields a value of a particular quantity. Van der Waals forces → The attractive or repulsive forces between molecular entities (or between groups within the same molecular entity) other than those due to bond formation or to the electrostatic interaction of ions or of ionic groups with one another or with neutral molecules. The term includes: dipole–dipole, dipole-induced dipole and London (instantaneous induced dipole-induced dipole) forces. The term is sometimes used loosely for the totality of nonspecific attractive or repulsive intermolecular forces. Vapnik-Chernowsky dimension, VC dimension (learning theory) → It characterizes classifiers, related to the classification “power” of Net(x,w), a measure of the capacity of a statistical classification algorithm. It gives the number of how many different separation is possible to made by the same architecture. Variable → The symbol of a quantity or an object meaning the place where we can store one amount of quantity. Variance → It is used as a measure of how far a set of samples are spread out from each other. Variational approach → The variational problem is equivalent to and allows for the derivation of the differential equations of motion of the physical system. Although formulated originally for classical mechanics, Hamilton’s principle also applies to classical fields such as the electromagnetic and gravitational fields, and has even been extended to quantum mechanics, quantum field theory. Variational calculus → ~ is a field of mathematics that deals with extremizing functionals, as opposed to ordinary calculus which deals with functions VC (Vapnik- -Chervonenkis) dimension (learning theory) → ~ characterizes classifiers, related to the classification “power” of the neural network (frequently denoted by Net(x,w)), a measure of the capacity of a statistical classification algorithm. It gives the number of how many different separation is possible to made by the same architecture Vector field → A ~ is an assignment of a vector to each point in a subset of Euclidean space. Vector potential → A ~ is a vector field whose curl is a given vector field. Vector superposition → In physics the superposition principle states that for all linear systems the net response at a given place and time caused by two or more stimuli is the sum of the responses which would have been caused by each stimulus individually. The superposition principle applies to any linear system. The stimuli and responses could be for example vectors or vector fields or any other object which satisfies certain axioms. When vectors or vector fields are involved, a superposition is interpreted as a vector sum. Vectorcardiogram (VCG) → Magnitude and direction of the electrical currents of the heart in the form of a vector loop. Vehicle (medical) → A substance of no therapeutic value used to convey an active medicine for administration. Velocity → In physics, ~ is the measurement of the rate and direction of change in the position of an object. It is a vector physical quantity; both magnitude and direction are required to define it. The scalar absolute value (magnitude) of ~ is speed, a quantity that is measured in m/s or ms−1. Velocity vector → Velocity is the rate of change of displacement which is the first time derivative of the position. Venn diagram → A graphical method to visualize sets and its oprations (invented by John Venn). For each set there is a corresponding bordered area in the plane representing that set. Ventral root → Fiber bundle of motor efferents carrying information from spinal segments to the target structure Ventricular tremor → The phenomenon of fibrillation is caused by the different contraction rhythm of the heart muscle fibers, when instead of contractions, the heart is only shaking. Very Large Scale Integration (VLSI) → It is the current level of computer microchip miniaturization. Very Long Instruction Word (VLIW) → VLIW refers to a CPU architecture designed to take advantage of instruction level parallelism Virtual cell → Nonexistent cells in the neighborhood of the boundary cells Visceral nervous system → The visceral part of the peripheral nervous system that comprises the whole complex of nerves, fibers, ganglia, and plexuses by which impulses travel from the central nervous system to the viscera and from the viscera to the central nervous system. It contains the usual afferent fibers that receive stimuli and carry impulses toward the central nervous system and efferent fibers that carry impulses from the appropriate centers to the active effector organs, such as the nonstriated muscle, cardiac muscle, and glands of the body. Viscoelasticity → The property of materials that exhibit both viscous and elastic characteristics when undergoing deformation Viscosity → Describes a fluid’s internal resistance to flow and may be regarded as the measure of fluid friction Visible light → ~ has a wavelength in a range from about 380 or 400 nanometres to about 760 or 780 nm, with a frequency range of about 405 THz to 790 THz. Visual evoked potential (VEP) → Response of the brain to a visual stimulus. Visuotopic/Retinotopic organization → RRetinotopy describes the spatial organization of the neuronal responses to visual stimuli. There is an orderly arrangement, which emerges from the spatial specificity of connections between neurons in different parts of the visual system; cells in each structure can be seen as forming a map of the visual field (also called a retinotopic map, or a visuotopic map). Vital Capacity → The sum of the tidal volume and the inspiratory and expiratory reserve. Its normal value is 4800 ml. Vivisection → The dissection of live animals to view their living internal structure. Voltage → It is an informal term for electric potential difference. Voltage clamp → ~ means that the membrane voltage is held (“clamped”) at a specific value by external current injection. Used to measure the ion currents across the membrane of excitable cells, such as neurons, while the membrane voltage is controlled. Voltage controled → A circuit element where the current on the output can be controlled by the input voltage. Voltage gated carriers → Carriers opening of which is regulated by the membrane potential around the protein. Voltage sensitive dyes (VSD) → Dyes that change their colour due to change in voltage. Voltage-dependent conductance → (or voltage-gated ion channel) A class of ion channels that are activated by changes in electrical potential difference near the channel (across the cell membrane). If activated, the channel becomes conductive to an ion specific for the channel. Voltage-gated ion channel → A class of ion channels that are activated by changes in electrical potential difference near the channel (across the cell membrane). If activated, the channel becomes conductive to an ion specific for the channel. Voltaic pile (galvanic cell) → It is the first electric battery invented by Alessandro Volta (1745–1827) in 1800. Also termed as galvanic cell. The device consists of pairs of alternating copper and zinc discs separated by cardboards soaked in salt water. The metal discs are the electrodes while the salt water playes the role of the electrolyte. Voxel → A three-dimensional volume element. 26. W Wafer → Thin disc of pure silicon upon which up to a couple of thousand semiconductor die can be manufactured simultaneously. Afterwards, the discs are cut apart into a single die in preparation for the package-assembly and test process steps, before finally being shipped to end users. Wafer bonding → ~ is a process of joining two or more wafers prior to dicing and packaging. Watchdog → A counter which the software sets to zero peri+B2556odically and the hardware is constantly scrolling it. If it reaches a certain value, it resets the device with the hardware, and restarts the program (because the software presumably is not running because of an error). Wave equation → The ~ is an important second-order linear partial differential equation for the description of waves – as they occur in. Wave function → It is a function of the spacial coordinates of the particle. It has no picturesque physical meaning but its square is the probability density function of the localization of the particle. Wave impedance → The ~ of an electromagnetic wave is the ratio of the transverse components of the electric and magnetic fields (the transverse components being those at right angles to the direction of propagation). Wave packet → A ~ is a short “burst” or “envelope” of wave action that travels as a unit. A wave packet can be analyzed into, or can be synthesized from, an infinite set of component sinusoidal waves of different wavenumbers, with phases and amplitudes such that they interfere constructively only over a small region of space, and destructively elsewhere. Depending on the evolution equation, the wave packet’s envelope may remain constant (no dispersion) or it may change (dispersion) while propagating. Waveform → Representation of a general periodic signal. Waveguide, rectangular, circular → A ~ is a structure which guides electromagnetic waves. The original and most common meaning is a hollow conductive metal pipe. Waveguides differ in their geometry. Wavelength → The ~ of a sinusoidal wave is the spatial period of the wave – the distance over which the wave’s shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase. Wavenumber → It is a property of a wave proportional to the reciprocal of the wavelength. Because of ~ is proportional to frequency for the case of an electromagnetic wave, wavenumbers are used as a unit of energy. Wavicle ~ wave-particle → The particle and wave ‘waveicle’ enigma (Feynman). It is not a wave. It is not a particle. It is both a wave and a particle together with their respective intrinsic properties of wavelength, frequency, linear and angular momentum. In addition a wavicle has intrinsic double spins. Both spins can singularly be described by a conserved mass independent local infinitesimal angular acceleration such that the scalar inner dot product of this acceleration and the local infinitesimal metric is a constant the square of light speed in vacuum. Weak acid → Weak acids are ionizing only slightly in water. Ka << [H2O] Weak base → Weak bases are ionizing only slightly in water. Weak nuclear force → Weak interaction /weak force/weak nuclear force is one of the four fundamental forces of nature, alongside the strong nuclear force, electromagnetism, and gravity. It is responsible for the radioactive decay of subatomic particles and begins the process known as nuclear fusion. Weak interactions affect all known fermions; that is, particles whose spin (a property of all particles) is a half-integer. Weakly stationary processes → Random processes, whereas the first and second order statistics are time invariant Weight matrix → Represenatation of the weights between neuron in HNN Weights (Neural Networks) → The connections between neurons. Wetting → Interactions between the molecules of the liquid and the surrounding materials, especially at a triple contact point Weyl → Hermann Klaus Hugo Weyl (1885–1955), German mathematican evolved the concept of continuous groups using matrix representations. Wheland intermediate (σ-complex/adduct) → The product formed by the attachment of an electrophilic or nucleophilic entering group or of a radical to a ring carbon of an aromatic species so that a new σ-bond is formed and the original conjugation is disrupted. The term may also be used for analogous adducts to unsaturated (and conjugated) systems in general. Wide sens stationary process (WSS) → A property of a random process. In weak sense a random process is stationer if the first two moments (mean and variance) does not change in time Wideband system → A system is typically described as wideband if the message bandwidth significantly exceeds the channel’s coherence bandwidth. Wien → Wilhelm Carl Werner Otto Fritz Franz Wien (1864–1928) was a German physicist. He used theories about heat and electromagnetism to deduce Wien’s displacement law, which calculates the emission of a blackbody at any temperature from the emission at any one reference temperature. Wien’s law → ~ tells us that objects of different temperature emit spectra that peak at different wavelengths. Hotter objects emit most of their radiation at shorter wavelengths; cooler objects emit most of their radiation at longer wavelengths. At any wavelength, a hotter object radiates more than a cooler one. Window function → It is zero-valued outside of some chosen interval. Wire bonding → Thermosonic ball and stitch bonding is the most widely used assembly technique in the semiconductors. Wireless sensor networks (WSN) → It consists of spatially distributed autonomous sensors to monitor physical or environmental condition.The sensor nodes cooperatively pass their data on wireless links through the network to Base Station. Wireless Spectrum → The range of electromagnetic waves used for radio communication in the range of about 3 kHz to 300 GHz. The ISM band radio frequencies used for license-free wireless communications allocated for industrial, scientific and medical processes. Wireless Telemedicine → Quality clinical and health care services at a distance over wireless communications and networking systems. Woodward–Hoffmann rules → The Woodward–Hoffmann rules devised by Robert Burns Woodward and Roald Hoffmann are a set of rules in organic chemistry predicting the stereochemistry of pericyclic reactions based on orbital symmetry. Three rules are stated as:
Working memory → A limited capacity part of the memory system in humans and other animals that combines the temporary storage and manipulation of information in the service of cognition. Workspace → ~ is an area which can be defined as the reachable field of the limb.It is strictly determined by: a) segment lengths’ of the limb b) the degree of freedom of the joints c) a range of joint angles limited by the minimum and maximum available angles. WSSUS model → The Wide-Sense Stationary Uncorrelated Scattering (WSSUS) model provides a statistical description of the transmission behavior of wireless channels. 27. X X-ray → X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 120 eV to 120 keV. X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen (1845–1923, was a German physicist), who is generally credited as its discoverer, and who had named it X-radiation to signify an unknown type of radiation. X-ray Crystallography → X-ray crystallography is a method of determining the arrangement of atoms within a crystal. The crystal is radiated by a beam of X-rays which diffracts into many specific directions. A three-dimensional picture of the density of electrons can be produce from the angles and intensities of these diffracted beams. With this procedure, the mean positions of the atoms in the crystal can be determined. X-ray tube → A special cathode ray tube used for x-ray production. 28. Y Yeast two-hybrid system (Y2H) → The yeast two-hybrid system is a library-based high throughput method for detecting protein-protein interactions. 29. Z ZENNER effect → If the emptied layer has a sufficiently big field strength, then it is able to tear out electrons from their ties and this way free charge carriers appear. Zero bit → This bit is set by the CPU (Central Processor Unit) if the result of the previous operation was zero; cleared otherwise. Zero order reaction → A reaction where the rate is independent of the concentration of a reactant is zero order with respect to that reactant. Zero temperature kinetic energy → At absolute zero, all solids with a lowest-energy crystal lattice such those with a closest-packed arrangement contain minimal internal energy, retaining only that due to the ever-present background of zero-point energy. For a given substance at constant pressure, absolute zero is the point of lowest enthalpy. It is always true to say that all T = 0 substances contain zero kinetic heat energy. Absolute zero is the theoretical temperature at which entropy reaches its minimum value. A system at absolute zero still possesses quantum mechanical zero-point energy, the energy of its ground state. The kinetic energy of the ground state cannot be removed. However, in the classical interpretation it is zero and the thermal energy of matter vanishes. Absolute zero is the null point of any thermodynamic temperature scale. Zero, pole → A zero is a root of the denominator of a rational fraction function Z-transform → a power series transform. See mathematical formulation for details 30. α α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) → A specific agonist of a subset of glutamate receptors (AMPA receptor). α-helix → A kind of secondary structural elements of proteins. It is a right handed helix. It has 3.6 amino acids per turn and an 1.5 Å translation along the axis. Every backbone carboxyl oxygen form a hydrogen bond with the amino hydrogen of the amino acid fourth ahead along the chain. 31. β β-Oxidation → metabolism of fatty acids by oxidation of the β-carbon (C3) with release of acetyl-CoA β-sheet → A planar bundle of β-strands where adjacent strands are connected by hydrogen bond. In parallel beta sheets the particular strands are oriented in the same direction while in anti-parallel sheets they are oriented in opposite direction. β-strand → A kind of secondary structural elements of proteins. It is the most extended structure allowed by spherical constraints. ??????? → An enzyme-catalyzed chemical process resulting in complex products formed out of substrates. ??????? → Spatial organization (including conformation) of an entire protein molecule Created by XMLmind XSL-FO Converter. Yüklə 295,25 Kb. Dostları ilə paylaş:
|