id
stringlengths
40
40
title
stringlengths
15
120
text
stringlengths
41
3.14k
source
stringclasses
2 values
bdd7d7bc7bab8ada63f9cb75856f7905ea51a1eb
where | Λ | {\displaystyle |\lambda |} represents
where | Λ | {\displaystyle |\lambda |} represents the volume of the parallelepiped formed by the vectors { v,..., v }. this periodic function is often referred to as the sampled spectrum and can be interpreted as the analogue of the discrete-time fourier transform (dtft) in higher dimensions. if the original wavenumber...
wikipedia
ea91dc6ecfa9c9be8014490e90159356758884f7
the generalization of the poisson summation formula to
the generalization of the poisson summation formula to higher dimensions can be used to show that the samples, { f (x): x ∈ Λ } {\displaystyle \{f(x):x\in \lambda \}}, of the function f (⋅) {\displaystyle f(\cdot)} on the lattice Λ {\displaystyle \lambda } are sufficient to create a periodic summation of the function f...
wikipedia
b4f39e8713d2098b2e0ff2bd89f291220f08fcc9
let Λ {\displaystyle \lambda } denote a lattice
let Λ {\displaystyle \lambda } denote a lattice in ℜ n {\displaystyle \re ^{n}} and Γ {\displaystyle \gamma } the corresponding reciprocal lattice. the theorem of petersen and middleton states that a function f (⋅) {\displaystyle f(\cdot)} that is wavenumber-limited to a set Ω ⊂ ℜ n {\displaystyle \omega \subset \re ^{...
wikipedia
becb5e7ea3bf6038d535ab0677feecc57c1c5e01
where the vectors u i {\displaystyle u_{i}} are
where the vectors u i {\displaystyle u_{i}} are chosen to satisfy ⟨ u i, v j ⟩ = δ i j {\displaystyle \langle u_{i},v_{j}\rangle =\delta _{ij}}. that is, if the vectors u i {\displaystyle u_{i}} form columns of a matrix a {\displaystyle a} and v i {\displaystyle v_{i}} the columns of a matrix b {\displaystyle b}, then ...
wikipedia
5cd0071e1aad0f6738a71f8a82d767e5cfa9c853
similarly, the configuration of uniformly spaced sampling points
similarly, the configuration of uniformly spaced sampling points in one-dimension can be generalized to a lattice in higher dimensions. a lattice is a collection of points Λ ⊂ ℜ n {\displaystyle \lambda \subset \re ^{n}} of the form Λ = { ∑ i = 1 n a i v i | a i ∈ z } {\displaystyle \lambda =\left\{\sum _{i=1}^{n}a_{i}...
wikipedia
aa63fc7f300d9ffa7d341c4ab06154d5c6e39e6a
where x and ξ are n -dimensional vectors,
where x and ξ are n -dimensional vectors, and ⟨ x, ξ ⟩ {\displaystyle \langle x,\xi \rangle } is the inner product of the vectors. the function f (⋅) {\displaystyle f(\cdot)} is said to be wavenumber-limited to a set Ω {\displaystyle \omega } if the fourier transform satisfies f ^ (ξ) = 0 {\displaystyle {\hat {f}}(\xi)...
wikipedia
cc74a055f6aa27e0829dc066f560a364f0719e73
the concept of a bandlimited function in one
the concept of a bandlimited function in one dimension can be generalized to the notion of a wavenumber-limited function in higher dimensions. recall that the fourier transform of an integrable function f (⋅) {\displaystyle f(\cdot)} on n -dimensional euclidean space is defined as:
wikipedia
7cee571675c3b829060f154cc31f4ef049982dd4
as with the nyquist–shannon sampling theorem, this theorem
as with the nyquist–shannon sampling theorem, this theorem also assumes an idealization of any real-world situation, as it only applies to functions that are sampled over an infinitude of points. perfect reconstruction is mathematically possible for the idealized model but only an approximation for real-world functions...
wikipedia
099de64d3db91f10f047f08e43c81269c66c57f2
in essence, the petersen–middleton theorem shows that a
in essence, the petersen–middleton theorem shows that a wavenumber-limited function can be perfectly reconstructed from its values on an infinite lattice of points, provided the lattice is fine enough. the theorem provides conditions on the lattice under which perfect reconstruction is possible.
wikipedia
99f4ca1b71728a7cb8e76a4fc080c7b71bc4ac14
in digital signal processing, multidimensional sampling is the
in digital signal processing, multidimensional sampling is the process of converting a function of a multidimensional variable into a discrete collection of values of the function measured on a discrete set of points. this article presents the basic result due to petersen and middleton on conditions for perfectly recon...
wikipedia
847184193f950133f67b31d470685d491365e2ef
kompressor is a marketing name for forced induction
kompressor is a marketing name for forced induction (supercharged) mercedes-benz engines. the term is not widely used by other motor manufacturers. the first mercedes supercharger was developed in 1921 by a daimler-benz team with assistance from ferdinand porsche. mercedes became the first manufacturer to install super...
wikipedia
6bc53141f32d4af69d48314ff0ad68d70106c0e0
amg phased out the supercharged 5.4 l engines
amg phased out the supercharged 5.4 l engines in favor of the new m156 v8 beginning in 2006, which was paired with 7g-tronic. however, some enthusiasts were disappointed because the m156 produces less torque than the supercharged m155.
wikipedia
a4d4dc313d509c5ac67d728232e81b92ba748e07
the v8 s55 amg had a comparable output
the v8 s55 amg had a comparable output to the v12-powered s600 throughout their production. the s55 amg (2001–02) was outfitted with a 5.4l 354 hp (264 kw) v8 motor while the later versions (2003–06) sported the same motor, but supercharged to a rated 493 hp (386 kw). the s600 (2001–02) was outfitted with a 5.8l 362 hp...
wikipedia
8d4d1cbd242497ea305d354356c961578a93570a
the m113k was mated to the speedshift 5-speed
the m113k was mated to the speedshift 5-speed automatic transmission, which has a torque capacity of 796 lb⋅ft (1,079 n⋅m), as the newer 7g-tronic introduced in 2003 is limited to 542 lb⋅ft (735 n⋅m), not enough to handle the torque from the supercharged v8.
wikipedia
dac42354eaa2715ae23867118c920e7d439a1d28
the m113 kompressor, also nicknamed m113k, is supercharged
the m113 kompressor, also nicknamed m113k, is supercharged variant of the m113 v8. it is a 5.4 l v8 engine with a lysholm type twin screw supercharger and water-to-air intercooler. the supercharger was developed in conjunction with ihi and features teflon -coated rotors, is found in the rest of the amg 55 models which ...
wikipedia
5667d2c28435b42fe9dc71a2103a71dd76b4ede5
the c32 had a smaller engine than its
the c32 had a smaller engine than its predecessors, the c36 amg with the m104 3.6l i6 engine, and the c43 amg powered by the m113 4.3l v8 engine. nonetheless, the c32 amg was capable of runs to 60 in 4.5 seconds, when reviewed by autocar on june 27, 2001, beating the bmw m3 and the porsche 911.
wikipedia
1cbab2a5c1292ad027bd050fb89bb1dd7986df97
while rival bmw m developed the smg-ii automated
while rival bmw m developed the smg-ii automated manual for the bmw m3, the c32 and slk32 have a 5-speed automatic transmission's "speedshift" system which now has quicker response (up to 35 percent) to accelerator and shift selector movements.
wikipedia
02effe38ff7e12894af354c961bb3c6b689cb51e
powertrain consists of amg speedshift black series 5-speed
powertrain consists of amg speedshift black series 5-speed automatic transmission mated to an amg 3.2 liter v6 kompressor engine with an output of 260 kw/349 hp and 332 lb⋅ft (450 n⋅m) @ 4,400 rpm. the engine is a special version of the 3.2 l (3199 cc) m112 e32, fitted with a helical twin-screw supercharger and water-t...
wikipedia
e7b7100e6eb161db23d6625b3455b5f345c83a25
initial engine options comprised the c 180 (139
initial engine options comprised the c 180 (139 ps), c220 (143 ps), c 200 kompressor, and c 230 kompressor. in 2003, mercedes-benz added the c 180 kompressor, followed by the c 200 compressor in 2003-2007 (187 hp), and finally the c 160 kompressor in 2005. the c 230 sportcoupé was powered by a 2.3-litre supercharged, f...
wikipedia
6893483f4493753f63305dd062ad8d2729657dd6
in 2002 for the 2003 model year, a
in 2002 for the 2003 model year, a new family of supercharged four cylinder engines, dubbed m271, debuted for the entire c-class range. all of them used the same 1.8-litre engine, with different designations according to horsepower levels, including a version powered by natural gas. the c 230 kompressor variant sported...
wikipedia
a514d940cc2b9ef235ca572e14473a80419dcfbf
the first mercedes supercharger was developed in 1921
the first mercedes supercharger was developed in 1921 by a daimler-benz team with assistance from ferdinand porsche. mercedes became the first manufacturer to install superchargers on some production models. the designation "k" on mercedes usually means "kurz", or short, but can mean "kompressor".
wikipedia
840c90d8bbd38a6b0f8d1248a3357d5029869b73
lund was president of the british phycological society
lund was president of the british phycological society in 1957. he was elected a fellow of the royal society (frs) in 1963 and made commander of the most excellent order of the british empire (cbe) in 1975. in 1975 he and hilda mabel canter-lund received the prescott award from the phycological society of america "for ...
wikipedia
3d724fbd3e069c44c1ac7f81b91bdfb7e0203bbd
in 1944 he joined the freshwater biological association
in 1944 he joined the freshwater biological association (fba) as scientific officer for algology, moving to windermere with the association's fritsch collection of freshwater algae in 1954. he retired in 1978, was appointed deputy chief scientific officer and then honorary advisor to the fba. in 1991 he was elected an ...
wikipedia
dabdc6b800cb18328d99cb0708a1a909b80ad292
he worked for a time as a lecturer
he worked for a time as a lecturer at the university of sheffield, and then joined the west midlands forensic science laboratory as staff biologist. while there he worked on the case of the unsolved murder victim who has become known as wych elm bella.
wikipedia
245c01835ab7cc3fd235ceff5fdd19f2c635bf8b
lund was born in 1912 and was educated
lund was born in 1912 and was educated at sedbergh school. he studied for his bachelor of science and master of science degrees at the university of manchester, before moving to the university of london in 1935. he was awarded his phd in 1939 and his dsc in 1951. in 1949 he married hilda mabel canter and they had two c...
wikipedia
f0bf4f4695da34e67a498d6c60b13bc6aadea050
nicolas fuss was married to albertine benedikte philippine
nicolas fuss was married to albertine benedikte philippine luise euler (1766-1822). albertine euler was the daughter of leonhard euler's eldest son johann albrecht euler (1734-1800) and his wife anna sophie charlotte hagemeister. pauline fuss, a daughter of nicolas and albertine, married russian chemist genrikh struve....
wikipedia
7d1c1194591ecf33f80c155c44e3212ccd87dccb
in 1797, he was elected a foreign member
in 1797, he was elected a foreign member of the royal swedish academy of sciences. from 1800 – 1826, fuss served as the permanent secretary to the imperial academy of sciences in saint petersburg. he was elected a foreign honorary member of the american academy of arts and sciences in 1812. he died in saint petersburg.
wikipedia
a046880b557db4bb51cc0d3fed66f742c415d636
fuss was born in basel, switzerland. he moved
fuss was born in basel, switzerland. he moved to saint petersburg to serve as a mathematical assistant to leonhard euler from 1773 – 1783, and remained there until his death. he contributed to spherical trigonometry, differential equations, the optics of microscopes and telescopes, differential geometry, and actuarial ...
wikipedia
ca8dd0c08aed173fce150b593624bfdd7d8e9849
jutta maria jokiranta is a finnish theologian and,
jutta maria jokiranta is a finnish theologian and, since 2018, a professor in hebrew bible and cognate studies at the university of helsinki. she is a former university lecturer of the hebrew bible at the university of helsinki and an academy research fellow of the academy of finland. her area of specialization is qumr...
wikipedia
8e113f87178195f6d62003dff0a447fd8cfe2bae
jutta maria jokiranta (née miettinen; born 14 april
jutta maria jokiranta (née miettinen; born 14 april 1971 in salla) is a finnish theologian and, since 2018, a professor in hebrew bible and cognate studies at the university of helsinki. she is a former university lecturer of the hebrew bible at the university of helsinki and an academy research fellow of the academy o...
wikipedia
9676aa2c21b29d4ac51df2e6607b3994b88c8e1f
a separator is a permeable membrane placed between
a separator is a permeable membrane placed between a battery's anode and cathode. the main function of a separator is to keep the two electrodes apart to prevent electrical short circuits while also allowing the transport of ionic charge carriers that are needed to close the circuit during the passage of current in an ...
wikipedia
a80a52752be505bb54b1d034bdf279f0505b0d90
inorganic polymer separators have also been of interest
inorganic polymer separators have also been of interest as use in lithium-ion batteries. inorganic particulate film/ poly(methyl methacrylate) (pmma) /inorganic particulate film trilayer separators are prepared by dip-coating inorganic particle layers on both sides of pmma thin films. this inorganic trilayer membrane i...
wikipedia
2d1a23289322caeae300e1d224eba6135c1bd4b5
ni/mh batteries of bipolar design (bipolar batteries) are
ni/mh batteries of bipolar design (bipolar batteries) are being developed because they offer some advantages for applications as storage systems for electric vehicles. this solid polymer membrane gel separator could be useful for such applications in bipolar design. in other words, this design can help to avoid short-c...
wikipedia
9e17bd16fcd63150b3ac3d44d1c0dffc26026789
the sealed rechargeable nickel-metal hydride battery offers significant
the sealed rechargeable nickel-metal hydride battery offers significant performance and environmental friendliness above alkaline rechargeable batteries. ni/mh, like the lithium-ion battery, provides high energy and power density with long cycle lives. this technology's greatest problem is its inherent high corrosion r...
wikipedia
e749038f91d888a142d1ee6b7ef6abcb1233c17e
plasma technology was used to modify a polyethylene
plasma technology was used to modify a polyethylene membrane for enhanced adhesion, wettability and printability. these are usually performed by modifying the membrane on only its outermost several molecular levels. this allows the surface to behave differently without modifying the properties of the remainder. the sur...
wikipedia
cfa76b0fd464d46bd1ced887d3fba30ede5a9cd5
in addition to polymer separators, there are several
in addition to polymer separators, there are several other types of separators. there are nonwovens, which consist of a manufactured sheet, web, or mat of directionally or randomly oriented fibers. supported liquid membranes, which consist of a solid and liquid phase contained within a microporous separator. additional...
wikipedia
9172a6c4c4dcfeed6f5a6b275c7fbfbd3b0e7ac3
separators are also subjected to numerous stresses during
separators are also subjected to numerous stresses during battery assembly and battery usage. common stresses include tensile stresses from dry/wet processes and compressive stresses from the volumetric expansion of electrodes and required forces to ensure sufficient contact between components. dendritic lithium growth...
wikipedia
dd83401a578dea51c3aabfbbc2b0320bff91fe14
polymer separators, similar to battery separators in general,
polymer separators, similar to battery separators in general, act as a separator of the anode and cathode in the li-ion battery while also enabling the movement of ions through the cell. additionally, many of the polymer separators, typically multilayer polymer separators, can act as “shutdown separators”, which are ab...
wikipedia
ef0ad3e5f591cdd00556763ffc1089b1578f8f31
many structural defects can form in polymer separators
many structural defects can form in polymer separators due to temperature changes. these structural defects can result in a thicker separators. furthermore, there can be intrinsic defects in the polymers themselves, such as polyethylene often begins to deteriorate during the stages of polymerization, transportation, an...
wikipedia
806dfbdfc7dc4e09a9f296b647fa2d13aef7b4eb
specific types of polymers are ideal for the
specific types of polymers are ideal for the different types of synthesis. most polymers currently used in battery separators are polyolefin based materials with semi-crystalline structure. among them, polyethylene, polypropylene, pvc, and their blends such as polyethylene-polypropylene are widely used. recently, graft...
wikipedia
2a329ebe82bf5a37b5d2bcbcd0693806415d599e
the wet process is suitable for both crystalline
the wet process is suitable for both crystalline and amorphous polymers. wet process separators often use ultrahigh-molecular-weight polyethylene. the use of these polymers enables the batteries with favorable mechanical properties, while shutting it down when it becomes too hot.
wikipedia
24081257b7c33331f29f205e22ab950a29515a2f
the wet process consists of mixing, heating, extruding,
the wet process consists of mixing, heating, extruding, stretching and additive removal steps. the polymer resins are first mixed with, paraffin oil, antioxidant and other additives. the mixture is heated to produce a homogenous solution. the heated solution is pushed through a sheet die to make a gel-like film. the ad...
wikipedia
4bbf10e2e61716171656660b29270f1869dfbbfa
after processing, separators formed from the dry process
after processing, separators formed from the dry process possess a porous microstructure. while specific processing parameters (such as temperature and rolling speed) influence the final microstructure, generally, these separators have elongated, slit-like pores and thin fibrils that run parallel to the machine directi...
wikipedia
01c981c95da9959af9e9ab2474bef02885c2572e
the dry process is only suitable for polymers
the dry process is only suitable for polymers with high crystallinity. these include but are not limited to: semi-crystalline polyolefins, polyoxymethylene, and isotactic poly (4-methyl-1-pentene). one can also use blends of immiscible polymers, in which at least one polymer has a crystalline structure, such as polyeth...
wikipedia
db29968b8de932d8915f01de4f21cec17f899651
the dry process involves extruding, annealing and stretching
the dry process involves extruding, annealing and stretching steps. the final porosity depends on the morphology of the precursor film and the specifics of each step. the extruding step is generally carried out at a temperature higher than the melting point of the polymer resin. this is because the resins are melted to...
wikipedia
8e597f6453bfeb916036362b347c28b29e24bb86
membranes synthesized by dry processes are more suitable
membranes synthesized by dry processes are more suitable for higher power density, given their open and uniform pore structure, while those made by wet processes are offer more charge/discharge cycles because of their tortuous and interconnected pore structure. this helps to suppress the conversion of charge carriers i...
wikipedia
a1336d1719d299340f52c5ef6c303ef19955955f
materials include nonwoven fibers (cotton, nylon, polyesters, glass),
materials include nonwoven fibers (cotton, nylon, polyesters, glass), polymer films (polyethylene, polypropylene, poly (tetrafluoroethylene), polyvinyl chloride), ceramic and naturally occurring substances (rubber, asbestos, wood). some separators employ polymeric materials with pores of less than 20 Å, generally too s...
wikipedia
bff573b6de94fbefe47a49687038cf529a8dd58a
initially, lithium cobalt oxide was used as the
initially, lithium cobalt oxide was used as the cathode and polyacetylene as the anode. later in 1985, it was found that using lithium cobalt oxide as the cathode and graphite as the anode produced an excellent secondary battery with enhanced stability, employing the frontier electron theory of kenichi fukui. this enab...
wikipedia
a84a079986cfd13af78a06cc7b49858fc6d5e0a2
unlike many forms of technology, polymer separators were
unlike many forms of technology, polymer separators were not developed specifically for batteries. they were instead spin-offs of existing technologies, which is why most are not optimized for the systems they are used in. even though this may seem unfavorable, most polymer separators can be mass-produced at a low cost...
wikipedia
5f85290d1bea373a5f1e5dd4e18e624143ff10e6
separators are critical components in liquid electrolyte batteries.
separators are critical components in liquid electrolyte batteries. a separator generally consists of a polymeric membrane forming a microporous layer. it must be chemically and electrochemically stable with regard to the electrolyte and electrode materials and mechanically strong enough to withstand the high tension d...
wikipedia
f2eb025107ce6a8a2be07484f6b9c871383b225c
a separator is a permeable membrane placed between
a separator is a permeable membrane placed between a battery's anode and cathode. the main function of a separator is to keep the two electrodes apart to prevent electrical short circuits while also allowing the transport of ionic charge carriers that are needed to close the circuit during the passage of current in an ...
wikipedia
671599a28d39cde13732f3dd1a10e69524e8e612
the all-ireland senior hurling championship of 1997 was
the all-ireland senior hurling championship of 1997 was the 111th staging of ireland's premier hurling competition. clare won the championship, beating tipperary 0-20 to 2-13 in the final at croke park, dublin.
wikipedia
fb723dd393dbfbf72632df5bd1beadd681d4ce3d
quarter-finals: (2 matches) these are two lone matches
quarter-finals: (2 matches) these are two lone matches between the connacht champions and the leinster runners-up, and the ulster champions and the munster runners-up. two teams are eliminated at this stage, while the winners advance to the all-ireland semi-finals.
wikipedia
0e00068c4ce4b2a07d1e3b63fcf689ab417c9d5b
final: (1 match) the winner of the semi-final
final: (1 match) the winner of the semi-final joins another ulster team to contest this game. one team is eliminated at this stage, while the winners advance to the all-ireland quarter-final where that play the munster runners-up.
wikipedia
b8e0763e8b9400eba4fcf1216ac9fcb6f4ba05cd
quarter-finals: (2 matches) the winner of the preliminary
quarter-finals: (2 matches) the winner of the preliminary round game joins three other leinster teams to make up the two quarter-final pairings. two teams are eliminated at this stage, while two teams advance to the leinster semi-finals.
wikipedia
0ea76275e1221cf9032d33693da1761390e9dcda
prior to the opening of the championship former
prior to the opening of the championship former all-ireland-winning manager Éamonn cregan gave his predictions for the upcoming championship in the irish times. as with the previous three championships the field was wide open. although they were the reigning champions, wexford were given little chance of making it two-...
wikipedia
f7535262a183e62fc13052d1e803bedbc3708de8
at the start of 1996 these proposals looked
at the start of 1996 these proposals looked unlikely of being introduced, however, a whistle-stop tour undertaken by the committee's secretary frank murphy and pat daly, the gaa's games development officer, had changed the position. in april 1996 the committee's proposals were accepted at the gaa's annual congress. mos...
wikipedia
89df259f4b2f32a18717ef69fb963a446d9831d1
in 1995 the hurling development committee began investigating
in 1995 the hurling development committee began investigating a way of improving hurling in general and revamping the championship. their proposals involved allowing the defeated munster and leinster finalists to re-enter the all-ireland championship. although the two provincial final winners would automatically qualif...
wikipedia
a2623b34d08d1f1de9e2f646ae31a18d829e0e91
since its inception in 1887 the championship had
since its inception in 1887 the championship had been played on a straight knock-out basis. if any team was defeated at any stage of the provincial or all-ireland competitions it meant automatic elimination. this system was deemed the fairest as the all-ireland champions would always be the team who won all of their ga...
wikipedia
6067cbc98def749fb7e5c2eabfb229c8d5b393ec
the all-ireland senior hurling championship of 1997 (known
the all-ireland senior hurling championship of 1997 (known for sponsorship reasons as the guinness hurling championship 1997) was the 111th staging of ireland 's premier hurling competition. clare won the championship, beating tipperary 0-20 to 2-13 in the final at croke park, dublin.
wikipedia
4328be4e4bb12c639615a71c8af2188faa32f0c9
in mathematics, the set of positive real numbers,
in mathematics, the set of positive real numbers, r > 0 = { x ∈ r ∣ x > 0 } , is the subset of those real numbers that are greater than zero. the non-negative real numbers, r ≥ 0 = { x ∈ r ∣ x ≥ 0 } , also include zero. although the symbols r + and r + are ambiguously used for either of these, the notation r + or r + f...
wikipedia
8658dd31416aeeafe91d33a0b507db5cde88f43a
the realms of business and science abound in
the realms of business and science abound in ratios, and any change in ratios draws attention. the study refers to hyperbolic coordinates in q. motion against the l axis indicates a change in the geometric mean x y, {\displaystyle {\sqrt {xy}},} while a change along h indicates a new hyperbolic angle.
wikipedia
146dde875e470d0ccbf7c5a63654c1967073d462
since r > 0 {\displaystyle \mathbb {r} _{>0}}
since r > 0 {\displaystyle \mathbb {r} _{>0}} is a group, q {\displaystyle q} is a direct product of groups. the one-parameter subgroups l and h in q profile the activity in the product, and l × h {\displaystyle l\times h} is a resolution of the types of group action.
wikipedia
a5c29a458b00a6323a1cebd502b69d37f72bdb01
the l ∪ h {\displaystyle l\cup h} forms
the l ∪ h {\displaystyle l\cup h} forms a trident while l ∩ h = (1, 1) {\displaystyle l\cap h=(1,1)} is the central point. it is the identity element of two one-parameter groups that intersect there: { { (e a, e a): a ∈ r }, × } on l and { { (e a, e − a): a ∈ r }, × } on h. {\displaystyle \{\left\{\left(e^{a},\ e^{a}\r...
wikipedia
5083325eee027f5675d342c25c6ce3a505141b1a
let q = r > 0 × r
let q = r > 0 × r > 0, {\displaystyle q=\mathbb {r} _{>0}\times \mathbb {r} _{>0},} the first quadrant of the cartesian plane. the quadrant itself is divided into four parts by the line l = { (x, y): x = y } {\displaystyle l=\{(x,y):x=y\}} and the standard hyperbola h = { (x, y): x y = 1 }. {\displaystyle h=\{(x,y):xy=...
wikipedia
ca41c7198ffdfd09bbd0962f9a9e880d77f3a35a
including 0, the set r ≥ 0 {\displaystyle
including 0, the set r ≥ 0 {\displaystyle \mathbb {r} _{\geq 0}} has a semiring structure (0 being the additive identity), known as the probability semiring; taking logarithms (with a choice of base giving a logarithmic unit) gives an isomorphism with the log semiring (with 0 corresponding to − ∞ {\displaystyle -\infty...
wikipedia
f4aefa263477a85fdd963cf44ceae2aed3f42e03
the utility of this measure is shown in
the utility of this measure is shown in its use for describing stellar magnitudes and noise levels in decibels, among other applications of the logarithmic scale. for purposes of international standards iso 80000-3, the dimensionless quantities are referred to as levels.
wikipedia
b5279219a2d59e11e6b21ba9a6bc75f16d077bbf
if ⊆ r > 0 {\displaystyle \subseteq \mathbb
if ⊆ r > 0 {\displaystyle \subseteq \mathbb {r} _{>0}} is an interval, then μ () = log (b / a) = log b − log a {\displaystyle \mu ()=\log(b/a)=\log b-\log a} determines a measure on certain subsets of r > 0, {\displaystyle \mathbb {r} _{>0},} corresponding to the pullback of the usual lebesgue measure on the real numbe...
wikipedia
8d69e2d79064b76fa175252f709881bcc7d40330
among the levels of measurement the ratio scale
among the levels of measurement the ratio scale provides the finest detail. the division function takes a value of one when numerator and denominator are equal. other ratios are compared to one by logarithms, often common logarithm using base 10. the ratio scale then segments by orders of magnitude used in science and ...
wikipedia
a7a23e9a81e918b9e67e1bb17c3ee472cbf371fb
in the study of classical groups, for every
in the study of classical groups, for every n ∈ n, {\displaystyle n\in \mathbb {n},} the determinant gives a map from n × n {\displaystyle n\times n} matrices over the reals to the real numbers: m (n, r) → r. {\displaystyle \mathrm {m} (n,\mathbb {r})\to \mathbb {r}.} restricting to invertible matrices gives a map from...
wikipedia
7cf47adc8901be770baaaff1f95a558e9d0a97da
the ordered set (r > 0, >) {\displaystyle
the ordered set (r > 0, >) {\displaystyle \left(\mathbb {r} _{>0},>\right)} forms a total order but is not a well-ordered set. the doubly infinite geometric progression 10 n, {\displaystyle 10^{n},} where n {\displaystyle n} is an integer, lies entirely in (r > 0, >) {\displaystyle \left(\mathbb {r} _{>0},>\right)} and...
wikipedia
8a5f741b7c2c89d5db82f6d1fbe6bcffa7485eba
r > 0 = (0, 1) ∪ {
r > 0 = (0, 1) ∪ { 1 } ∪ (1, ∞) {\displaystyle \mathbb {r} _{>0}=(0,1)\cup \{1\}\cup (1,\infty)} and the multiplicative inverse function exchanges the intervals. the functions floor, floor:, {\displaystyle \left,} which is a sequence of integers obtained from the floor function after the excess has been reciprocated. f...
wikipedia
bb684b41638df273594c59c5a77c7fbf5bfb12be
for a given positive real number x, {\displaystyle
for a given positive real number x, {\displaystyle x,} the sequence { x n } {\displaystyle \left\{x^{n}\right\}} of its integral powers has three different fates: when x ∈ (0, 1), {\displaystyle x\in (0,1),} the limit is zero; when x = 1, {\displaystyle x=1,} the sequence is constant; and when x > 1, {\displaystyle x>1...
wikipedia
cefc84290fb7a042fe8838ea1d976df529437bcb
the set r > 0 {\displaystyle \mathbb {r}
the set r > 0 {\displaystyle \mathbb {r} _{>0}} is closed under addition, multiplication, and division. it inherits a topology from the real line and, thus, has the structure of a multiplicative topological group or of an additive topological semigroup.
wikipedia
14006abbbeb539fb745ed22679c9d060dd58e83f
in a complex plane, r > 0 {\displaystyle
in a complex plane, r > 0 {\displaystyle \mathbb {r} _{>0}} is identified with the positive real axis, and is usually drawn as a horizontal ray. this ray is used as reference in the polar form of a complex number. the real positive axis corresponds to complex numbers z = | z | e i φ, {\displaystyle z=|z|\mathrm {e} ^{\...
wikipedia
93ca67c7ee89153ad5a1934344d42e3d83161c51
in mathematics, the set of positive real numbers,
in mathematics, the set of positive real numbers, r > 0 = { x ∈ r ∣ x > 0 }, {\displaystyle \mathbb {r} _{>0}=\left\{x\in \mathbb {r} \mid x>0\right\},} is the subset of those real numbers that are greater than zero. the non-negative real numbers, r ≥ 0 = { x ∈ r ∣ x ≥ 0 }, {\displaystyle \mathbb {r} _{\geq 0}=\left\{x...
wikipedia
2bd6218f50b4adec85d693e8d78fd8eb8438afb7
a rangefinder is a device used to measure
a rangefinder is a device used to measure distances to remote objects. originally optical devices used in surveying, they soon found applications in other fields, such as photography, the military, and space travel. they were especially useful for finding the range of a target, such as in naval gunnery and anti-aircraf...
wikipedia
f8ffcb4700a1768758c27d0af4f5117efb3d6ed8
rangefinders may be used by users of firearms
rangefinders may be used by users of firearms over long distances, to measure the distance to a target to allow for projectile drop. until the development of electronic means of measuring range during the second world war, warships used very large optical rangefinders—with a baseline of many meters—to measure range for...
wikipedia
3280d613b10b17413d5615d281ec400c561e1def
laser rangefinders are used in golf to measure
laser rangefinders are used in golf to measure the yardage of a particular shot but also to gauge slope and wind as well. there has been debate over whether they should be allowed in tournaments. while their use is banned on the professional level, they are becoming widely used on the amateur level.
wikipedia
44f23cb45db34169f39615149ce2be4c3046c765
world war ii -era rangefinders worked optically with
world war ii -era rangefinders worked optically with two telescopes focused on the same target but a distance apart along a baseline. the range to the target is found by measuring the difference in bearing of the two telescopes and solving the skinny triangle. solutions can be obtained automatically, using tables or, r...
wikipedia
38853b81909ed6d6c578f30ea1601c1a18e1c996
in 1881, the british royal artillery adopted the
in 1881, the british royal artillery adopted the depression range finder, which had been developed by captain h.s.s. watkin for use by coastal artillery. it used the measurement of the angle of depression from the observer, sited on a high vantage point, to the waterline of the target vessel.
wikipedia
f5e0462fb30e6978c2b1a4d6b7acb9f421a50a3a
in 1778, georg friedrich brander invented the coincidence
in 1778, georg friedrich brander invented the coincidence rangefinder. two mirrors set a distance apart horizontally in a long slim box, similar to a subtense bar but located at the measuring station, and forming two images. this rangefinder does not require a measuring rod at the target and could perhaps be considered...
wikipedia
154b81da81db8e4342786df5bf6078374973b15b
several others have been credited with the invention
several others have been credited with the invention of the rangefinder telemeter at one time or another. the royal society of arts gave an award to w. green for its invention in 1778, even though they were made aware of watt's priority.
wikipedia
b911ecc0947dd294b984ddcdf62b33ffbcd07f9c
the first rangefinder telemeter was invented by james
the first rangefinder telemeter was invented by james watt in 1769 and put to use in 1771 in surveying canals. watt called his instrument a micrometer, a term now used with a different meaning in engineering (the micrometer screw gauge). it consisted of two parallel hairs in the focal plane of a telescope eyepiece cros...
wikipedia
29c4da2659e9292128ad4c0394671d9d69445a65
a rangefinder (also rangefinding telemeter, depending on the
a rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. originally optical devices used in surveying, they soon found applications in other fields, such as photography, the military, and space travel. they were especially useful for finding the rang...
wikipedia
214a3daed65c8b321d051e08ad3a03fa6c3edc4c
representation theory is a branch of mathematics that
representation theory is a branch of mathematics that studies abstract algebraic structures by representing their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures. in essence, a representation makes an abstract algebraic object more concrete by describing...
wikipedia
3f47d37f17a5a67079850d137ad441188b03962c
has an impact in number theory via automorphic
has an impact in number theory via automorphic forms and the langlands program. there are diverse approaches to representation theory. the same objects can be studied using methods from algebraic geometry, module theory, analytic number theory, differential geometry, operator theory, algebraic combinatorics and topolog...
wikipedia
354a03fac6253fbe39571afb135aa9c6a52ebdf3
one special case has had a significant impact
one special case has had a significant impact on representation theory, namely the representation theory of quivers. a quiver is simply a directed graph (with loops and multiple arrows allowed), but it can be made into a category (and also an algebra) by considering paths in the graph. representations of such categorie...
wikipedia
1f7fa76f60300d1b634e3c119495682f7321af43
since groups are categories, one can also consider
since groups are categories, one can also consider representation of other categories. the simplest generalization is to monoids, which are categories with one object. groups are monoids for which every morphism is invertible. general monoids have representations in any category. in the category of sets, these are mono...
wikipedia
de35f535cfb8bb594303b8183bb1b84546afd99c
every group g can be viewed as a
every group g can be viewed as a category with a single object; morphisms in this category are just the elements of g. given an arbitrary category c, a representation of g in c is a functor from g to c. such a functor selects an object x in c and a group homomorphism from g to aut(x), the automorphism group of x.
wikipedia
b2b3587b9b6b154c7df969e162e65c4f2936cf36
this condition and the axioms for a group
this condition and the axioms for a group imply that ρ (g) is a bijection (or permutation) for all g in g. thus we may equivalently define a permutation representation to be a group homomorphism from g to the symmetric group s of x.
wikipedia
ab04ae3102eb9c68cc5c49b8def46fb7ec8f048f
a set-theoretic representation (also known as a group
a set-theoretic representation (also known as a group action or permutation representation) of a group g on a set x is given by a function ρ from g to x, the set of functions from x to x, such that for all g, g in g and all x in x:
wikipedia
dd28db81c1878511b7e8a0f8182be058632ca1c8
the hopf algebras associated to groups have a
the hopf algebras associated to groups have a commutative algebra structure, and so general hopf algebras are known as quantum groups, although this term is often restricted to certain hopf algebras arising as deformations of groups or their universal enveloping algebras. the representation theory of quantum groups has...
wikipedia
2efb0bb9aff8d0cafaa058f86f050cfe3a541cbe
hopf algebras provide a way to improve the
hopf algebras provide a way to improve the representation theory of associative algebras, while retaining the representation theory of groups and lie algebras as special cases. in particular, the tensor product of two representations is a representation, as is the dual vector space.
wikipedia
d822043fed562c8c9558f8e2aa749f2d82152257
when considering representations of an associative algebra, one
when considering representations of an associative algebra, one can forget the underlying field, and simply regard the associative algebra as a ring, and its representations as modules. this approach is surprisingly fruitful: many results in representation theory can be interpreted as special cases of results about mod...
wikipedia
bab5e89648fb37ad89042f32adeb211c1a1c9903
in one sense, associative algebra representations generalize both
in one sense, associative algebra representations generalize both representations of groups and lie algebras. a representation of a group induces a representation of a corresponding group ring or group algebra, while representations of a lie algebra correspond bijectively to representations of its universal enveloping ...
wikipedia
4cc248f02717e1589d7aabe5485477449b1699f6
before the development of the general theory, many
before the development of the general theory, many important special cases were worked out in detail, including the hilbert modular forms and siegel modular forms. important results in the theory include the selberg trace formula and the realization by robert langlands that the riemann–roch theorem could be applied to ...
wikipedia
7cb267b7f26d072ef9c394cb7008fd0a6c39afd5
automorphic forms are a generalization of modular forms
automorphic forms are a generalization of modular forms to more general analytic functions, perhaps of several complex variables, with similar transformation properties. the generalization involves replacing the modular group psl (r) and a chosen congruence subgroup by a semisimple lie group g and a discrete subgroup Γ...
wikipedia
0251f82eca9261c3f15a0f065c6d7feefd44d4ff
the representation theory of semisimple lie groups has
the representation theory of semisimple lie groups has its roots in invariant theory and the strong links between representation theory and algebraic geometry have many parallels in differential geometry, beginning with felix klein 's erlangen program and Élie cartan 's connections, which place groups and symmetry at t...
wikipedia
868de828062cec844a53ff2bf73b71a8d4526389
invariant theory of infinite groups is inextricably linked
invariant theory of infinite groups is inextricably linked with the development of linear algebra, especially, the theories of quadratic forms and determinants. another subject with strong mutual influence is projective geometry, where invariant theory can be used to organize the subject, and during the 1960s, new life...
wikipedia