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data
: statements accepted at a given value (face value); Latin data
is the plural of datum. A large class of practically
important statements are measurements or observations of physical
system properties; such statements may comprise numbers, words, or
images. NOTE : term data should
be used in English with a plural verb, e.g. " the data are
inconclusive". |
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datum
: a statement accepted at a given value (face value); Latin datum
is neuter past participle of dare (to give), hence 'something
given'. (a "given"). NOTE :
term data, the plural of datum, is used more often in
English. |
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dB : see
decibel |
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dBa
: dimensionless unit used for A-weighted sound levels, an adjusted
acoustic scale.
Since the human ear is
not equally sensitive to all the frequencies of sound within the
entire spectrum, noise levels at maximum human sensitivity - middle
A and its higher harmonics (from 2 to 4 kHz) - are factored more
heavily into sound descriptions using a process called frequency
weighting.
The most widely used
frequency weighting is the ‘A-weighting’, which roughly
corresponds to the inverse of the 40 dB (at 1 kHz) equal-loudness
curve, i.e. ‘A weighting’ parallels the sensitivity of the human
ear.
Frequency weighted sound
levels are still expressed in decibels (dB), although symbol dBa is
commonly used for A-weighted sound levels. |
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economics |
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debt
: a sum of money or other property owed by one person or
organization to another; debt comes into being through the granting
of credit or through raising loan capital. |
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money
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decibel
(dB) : one tenth of bell (B) : dimensionless unit used in
electronics, telecommunication and acoustics to express the ratio of
two magnitudes on the common logarithmic scale; if I1
and I2 are the magnitudes of two
same kind signals, then the number of decibels, n,
expressing their ration is
n
= 10 lg(I1/I2)
Magnitude
Ii could be any physical quantity characteristic
for a particular signal, e.g. voltage, current or power for an
electric signal, and sound pressure for loudness in acoustics. If a
reference magnitude I0 is
established for a particular signal, then any signal of the same
kind could be referenced to it by the number of decibels. For
example, the minimum detectable sound pressure level by average
human ear is established as 20 µPa, and this value is set as a
reference magnitude in acoustics. Then, by definition that level is
0 dB, the threshold loudness level. The sensitivity of the average
human ear ranges from about 0 dB to about 140 dB, the level at which
pain sets in. |
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botany
& gardening |
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decurrent
: extending down the stem below from the place of insertion, as
certain leaves |
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botany
& gardening |
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dehiscent
: opening or splitting at maturity to discharge seeds (used of a
seed pod), or opening to discharge pollen (used of an anther). |
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botany
& gardening |
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dentate
: having a toothed margin or toothlike projection, as the edges of
leaves. |
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derived
(measurement) unit : a unit of measurement derived from
basic
units. Each system of measurement units has certain number of units
(called "basic units") defined by standards, while the rest of units is
derived from the basic units.
EXAMPLE: Electrical
potential
is defined as work performed per unit of electrical charge;
consequently SI
unit of electrical potential, V (volt) could be expressed as V = J/C,
where
J (joule) is SI unit of work & energy and C (coulomb) is SI unit of
electrical charge. However, neither J nor C are basic units in SI, so
V = J/C = (kg m s-2)/(A s) = kg
m s-3 A-1
where kg (kilogram), m (meter), s (second) and A (ampere) are basic
SI units. |
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basic
units
SI |
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device
: a technical artifact, i.e. any artifact which is not a piece of
art. |
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artifact |
meteorology |
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dew
: atmospheric moisture that has
condensed on objects near the ground, whose temperatures have fallen
below the dew point temperature. |
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meteorology |
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dew
point (temperature)
: a measure of atmospheric moisture : the temperature to which
air must be cooled in order to reach saturation (assuming air
pressure and moisture content are constant). A higher dew point
(temperature) indicates more moisture present in the air. Note:
sometimes written as one word : dewpoint. |
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diaspora
: any people or ethnic population forced or induced to leave their
traditional ethnic homelands, being dispersed throughout other parts
of the world, and the ensuing developments in their dispersal and
culture; from ancient Greek *4"FB@DV
(a scattering or sowing of seeds).
NOTE:
originally, the term was used to refer specifically to the
populations of Jews exiled from Judea in 586 BC by the Babylonians,
and Jerusalem in 135 AD by the Roman Empire: "thou shalt be a
diaspora in all kingdoms of the earth". |
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botany
& gardening |
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diclinous
: (of a plant species, variety, etc.) unisexual flowers, having the
stamens and the pistils in separate flowers, either on the same
plant or on different plants; either monoecious or dioecious. |
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digit
: any numeral from 0 to 9, especially when forming part of an arabic
number; in computing the term has a broader meaning: it includes any
one of the decimal characters 0 through 9, either of the binary
characters 0 or 1, and the digits 0...9, A...F used in the
hexadecimal system. |
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digital
: a system presentation by binary numbers (a pattern of 0s and
1s) for input, processing, transmission, storage, or display, rather
than a continuous spectrum of values (an analog system) or
non-numeric symbols such as letters or icons. In such a system
data-carrying signals are restricted to one of the two electronic or
optical pulses, either logic 1 (where the pulse is present) or 0
(where the pulse is absent). |
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digraph
: a pair of signs or symbols (two graphs), which together represent
a single sound or a single linguistic unit. The English writing
system employs many digraphs (for example, th, ch,
sh, qu, and so on). The same two symbols may not always be
interpreted as a digraph (for example, cathode
versus cathouse). |
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botany
& gardening |
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dioecious
: having the male and female organs in separate and distinct
individuals; plants having male flowers on one plant and female on
another. |
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botany
& gardening |
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dissepiment
: a partition formed in an ovary by the united sides of cohering
carpels, separating the inside into cells. |
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dispersoid
: a substance in the disperse phase, i.e. a substance consisting of
particles or droplets distributed through another substance. |
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computing
& web |
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dither
: a form of noise, or 'erroneous' signal or data which is intentionally
added to sample data to minimize undesirable effects in digital
signal processing, where a continuous range of values (or a very
large set of possible discrete values) is approximated by a
relatively small set of discrete symbols or integer values. |
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acronym |
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DIY
: Do It Yourself : the phrase along with
its acronym fell into common usage in the 1950s in reference to
various jobs that people could do in and around their houses without
the the aid of paid professionals, using their own abilities and
available tools and procedures. Moreover, as a subculture, DIY
movement confronts consumer culture which emphasizes a purchase as
the solution to all our needs. |
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doctrine
: a principle or body of principles presented for acceptance or
belief, as by a religious, political, scientific, or philosophic
group. |
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principle |
meteorology |
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drizzle
: precipitation consisting of numerous
minute droplets of water less than 0.5 mm in diameter. |
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botany
& gardening |
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drupe
: any fruit consisting of an outer skin, a usually pulpy and
succulent middle layer, and a hard and woody inner shell usually
enclosing a single seed; fruit with a hard kernel and a fleshy
pericarp, as in cherry, peach, apricot, plum, etc. |
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computing
& web acronym |
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DSL
: Digital Subscriber Line : a high-bandwidth Internet
connection over a telephone line. |
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bandwidth |
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