ideal ohm 's law plasma given math mathbf e mathbf v times mathbf b math faraday 's law math frac partial mathbf b partial nabla times mathbf e math low frequency amp 's law neglects displacement current given math mu mathbf j nabla times mathbf b math magnetic divergence constraint math nabla cdot mathbf b math energy equation given math frac mathrm mathrm left frac p rho gamma right math ratio specific heats adiabatic equation state energy equation applicable absence shocks heat conduction assumes entropy fluid element


change applicability ideal mhd plasmas ideal mhd strictly applicable plasma strongly collisional time scale collisions shorter characteristic times system particle distributions therefore close maxwellian resistivity due collisions small particular typical magnetic diffusion times scale length present system must longer time scale interest interest length scales much longer ion skin depth larmor radius perpendicular

Natural science
Space science
Numerical simulations
Magnetohydrodynamics


solar active region collisional resistivity hundreds thousands years much longer actual lifetime sunspot would seem reasonable ignore resistivity contrast meter sized volume seawater magnetic diffusion time measured milliseconds even physical systems large conductive enough simple estimates lundquist number suggest resistivity ignored resistivity may still important many instabilities exist increase effective resistivity plasma factors sup sup enhanced resistivity usually


result formation small scale structure like current sheets fine scale magnetic turbulence introducing small spatial scales system ideal mhd broken magnetic diffusion occur quickly happens magnetic reconnection may occur plasma release stored magnetic energy waves bulk mechanical acceleration material particle acceleration heat magnetic reconnection highly conductive systems important concentrates energy time space gentle forces applied plasma long periods time cause violent explosions bursts radiation


fluid cannot considered completely conductive conditions ideal mhd satisfied possible use extended model called resistive mhd includes extra term ohm 's law models collisional resistivity generally mhd computer simulations least somewhat resistive computational grid introduces numerical resistivity importance kinetic effects another limitation mhd fluid theories general depend assumption plasma strongly collisional first criterion listed time scale collisions


shorter characteristic times system particle distributions maxwellian usually case fusion space astrophysical plasmas case interest smaller spatial scales may necessary use kinetic model properly accounts non maxwellian shape distribution function however mhd relatively simple captures many important properties plasma dynamics often qualitatively accurate therefore often first model tried effects essentially kinetic captured


fluid models include double layers landau damping wide range instabilities chemical separation space plasmas electron runaway case ultra high intensity laser interactions incredibly short timescales energy deposition mean hydrodynamic codes fail capture essential physics structures mhd systems schematic view different current systems shape earth 's magnetosphere many mhd systems electric current compressed thin nearly two dimensional ribbons termed current sheets divide fluid magnetic domains inside currents relatively weak current


sheets solar corona thought meters kilometers thickness quite thin compared magnetic domains thousands hundreds thousands kilometers across another example earth 's magnetosphere current sheets separate topologically distinct domains isolating earth 's ionosphere solar wind waves wave modes derived using mhd plasma theory called '''magnetohydrodynamic waves''' '''mhd waves''' general three mhd wave modes pure oblique alfv n wave slow mhd wave fast mhd wave


image mhd wave mode svg alt math v v math caption image mhd wave mode svg alt math v v math caption waves constant phase velocities frequencies hence dispersion limits angle wave propagation vector magnetic field either wave modes called class wikitable style margin em auto em auto name type propagation phase velocity association medium names sound wave longitudinal adiabatic sound velocity none compressible nonconducting fluid alfv n wave transverse alfv n velocity


additionally dispersion equation gives math frac omega k left tfrac left v v right pm tfrac sqrt left v v right v v cos theta right frac math math v sqrt frac gamma p rho math ideal gas speed sound plus branch corresponds fast mhd wave mode minus branch corresponds slow mhd wave mode mhd oscillations damped fluid perfectly conducting finite conductivity viscous effects present mhd waves oscillations popular tool remote diagnostics laboratory astrophysical plasmas example corona sun coronal seismology extensions


resistive resistive mhd describes magnetized fluids finite electron diffusivity diffusivity leads breaking magnetic topology magnetic field lines 'reconnect' collide usually term small reconnections handled thinking dissimilar shocks process shown important earth solar magnetic interactions extended extended mhd describes class phenomena plasmas higher order resistive mhd adequately treated single fluid description include effects


hall physics electron pressure gradients finite larmor radii particle gyromotion electron inertia two fluid two fluid mhd describes plasmas include non negligible hall electric field result electron ion momenta must treated separately description closely tied maxwell 's equations evolution equation electric field exists hall j lighthill criticized applicability ideal resistive mhd theory plasmas concerned neglect hall current term frequent simplification made magnetic fusion theory hall magnetohydrodynamics


hmhd takes account electric field description magnetohydrodynamics important difference absence field line breaking magnetic field tied electrons bulk fluid electron mhd electron magnetohydrodynamics emhd describes small scales plasmas electron motion much faster ion one main effects changes conservation laws additional resistivity importance electron inertia many effects electron mhd similar effects two fluid mhd hall mhd emhd especially important z pinch magnetic reconnection ion


thrusters neutron stars plasma switches collisionless mhd also often used collisionless plasmas case mhd equations derived vlasov equation ref name space w baumjohann r treumann ''basic space plasma physics'' imperial college press ref reduced using multiscale analysis resistive mhd equations reduced set four closed scalar equations allows amongst things efficient numerical calculations ref name paper hegna ref applications geophysics beneath earth 's mantle lies core made two parts solid inner


core liquid outer core significant quantities iron liquid outer core moves presence magnetic field eddies set due coriolis effect eddies develop magnetic field boosts earth 's original magnetic field process self sustaining called geomagnetic dynamo ref name pbs https wwwpbsorg wgbh nova magnetic reve driveshtml nova magnetic storm drives earth 's magnetic field pbs ref reversals earth 's magnetic field based mhd equations glatzmaier paul roberts made supercomputer model earth 's interior running simulations


thousands years virtual time changes earth 's magnetic field studied simulation results good agreement observations simulations correctly predicted earth 's magnetic field flips every hundred thousand years flips magnetic field vanish altogether gets complex ref name glatz https sciencenasagov science news science nasa dec magneticfield earth 's inconstant magnetic field nasa science ref earthquakes monitoring stations reported earthquakes sometimes preceded spike ultra low frequency ulf activity remarkable example occurred loma prieta earthquake


california although subsequent study indicates little sensor malfunction december geoscientists announced demeter satellite observed dramatic increase ulf radio waves haiti month magnitude nbsp sub w sub earthquake researchers attempting learn correlation find whether method used part early warning system earthquakes astrophysics mhd applies astrophysics including stars interplanetary medium space planets possibly within interstellar medium space stars jets


astrophysical systems local thermal equilibrium therefore require additional kinematic treatment describe phenomena within system see astrophysical plasma sunspots caused sun 's magnetic fields joseph larmor theorized solar wind also governed mhd differential solar rotation may long term effect magnetic drag poles sun mhd phenomenon due parker spiral shape assumed extended magnetic field sun previously theories describing formation sun planets could explain


sun mass yet angular momentum solar system closed system cloud gas dust sun formed mass angular momentum conserved conservation would imply mass concentrated center cloud form sun would spin faster much like skater pulling arms high speed rotation predicted early theories would flung proto sun apart could formed however magnetohydrodynamic effects transfer sun 's


angular momentum outer solar system slowing rotation breakdown ideal mhd form magnetic reconnection known likely cause solar flares magnetic field solar active region sunspot store energy released suddenly burst motion x rays radiation main current sheet collapses reconnecting field sensors magnetohydrodynamic sensors used precision measurements angular velocities inertial navigation systems aerospace engineering accuracy improves size sensor sensor capable surviving


harsh environments engineering mhd related engineering problems plasma confinement liquid metal cooling nuclear reactors electromagnetic casting among others magnetohydrodynamic drive mhd propulsor method propelling seagoing vessels using electric magnetic fields moving parts using magnetohydrodynamics working principle involves electrification propellant gas water directed magnetic field pushing vehicle opposite direction although working prototypes exist mhd drives remain impractical first prototype kind propulsion built tested


steward way professor mechanical engineering university california santa barbara way leave job westinghouse electric assigned senior year undergraduate students develop submarine new propulsion system early foundation japan ship ocean foundation minato ku tokyo built experimental boat ''yamato '' used magnetohydrodynamic drive incorporating superconductor cooled liquid helium could travel nbsp km h ref name yamato setsuo takezawa et al march ''operation thruster superconducting electromagnetohydrodynamic propu sion ship yamato '' ref mhd power generation fueled


potassium seeded coal combustion gas showed potential efficient energy conversion absence solid moving parts allows operation higher temperatures failed due cost prohibitive technical difficulties one major engineering problem failure wall primary coal combustion chamber due abrasion microfluidics mhd studied fluid pump producing continuous nonpulsating flow complex microchannel design ref name nguyen ref mhd implemented continuous casting process metals suppress instabilities control flow industrial mhd problems modeled using open source software eof library two simulation


examples mhd free surface electromagnetic levitation melting liquid metal stirring rotating permanent magnets magnetic drug targeting important task cancer research developing precise methods delivery medicine affected areas one method involves binding medicine biologically compatible magnetic particles ferrofluids guided target via careful placement permanent magnets external body magnetohydrodynamic equations finite element analysis used study interaction magnetic fluid particles bloodstream external magnetic field see also


computational magnetohydrodynamics electrohydrodynamics electromagnetic pump ferrofluid list plasma physics articles lorentz force velocity meter magnetic flow meter magnetohydrodynamic generator magnetohydrodynamic turbulence molten salt plasma stability shocks discontinuities magnetohydrodynamics notes references bansal j l ''magnetofluiddynamics viscous fluids'' jaipur publishing house jaipur india biskamp dieter ''nonlinear magnetohydrodynamics'' cambridge england cambridge university press p nbsp calvert james b october https webarchiveorg web http wwwduedu jcalvert phys mhdhtm magnetohydrodynamics dynamics conducting fluids electromagnetic field self published associate professor emeritus engineering university denver usa davidson peter alan may ''an introduction


magnetohydrodynamics'' cambridge university press cambridge england faraday experimental researches electricity first series ''philosophical transactions royal society'' pp nbsp ferraro vincenzo consolato antonio plumpton charles ''an introduction magneto fluid mechanics'' nd ed galtier sebastien http wwwcambridgeorg fr academic subjects physics plasma physics fusion physics introduction modern magnetohydrodynamicsformat hb fktjat pcsurpkl introduction modern magnetohydrodynamics cambridge university press cambridge england p haverkort jw ''magnetohydrodynamics'' short introduction fluid dynamicists http jwhaverkortnet net documents mhdpdf magnetohydrodynamics hughes william f young frederick j ''the electromagnetodynamics fluids'' john wiley new york kulikovskiy andre g lyubimov grigori ''magnetohydrodynamics'' addison wesley reading massachusetts lorrain paul lorrain fran ois houle st phane ''magneto fluid


magnetohydrodynamics'' mcgraw hill book company new york van wie https webarchiveorg web http ftprtanatoint public pubfulltext rto en rto en avt en avt pdf future technologies application plasma devices vehicle systems johns hopkins university applied physics laboratory laurel maryland usa nato document http wwwbookragscom research magnetohydrodynamics mee magnetohydrodynamics ''in'' zumerchik john editor ''macmillan encyclopedia energy'' macmillan reference usa new york plasma physics


personnel integrity confidence organizational culture motivation team spirit quality relationships inspection major component quality control physical product examined visually end results service analyzed product inspectors provided lists descriptions unacceptable product defects cracks surface blemishes example ref name aftfunda history introduction early stone tools anvils holes designed interchangeable parts mass production established processes creation parts system identical dimensions design processes uniform

Applied science
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hence customers unsatisfied result quality control separates act testing products uncover defects decision allow deny product release may determined fiscal constraints ref name shewhart ref contract work particularly work awarded government agencies quality control issues among top reasons renewing contract simplest form quality control sketch desired item sketch match item rejected simple go go procedure however manufacturers soon found difficult costly make


parts exactly like depiction hence around tolerance limits introduced wherein design would function parts measured within limits quality thus precisely defined using devices plug gauges ring gauges however address problem defective items recycling disposing waste adds cost production trying reduce defect rate various methods proposed prioritize quality control issues determine whether leave unaddressed use quality assurance techniques improve stabilize production ref name shewhart


notable approaches tendency individual consultants organizations name unique approaches quality control ended widespread use class wikitable terminology approximate year first use description statistical quality control sqc application statistical methods specifically control charts acceptance sampling quality control ref name juran ref total quality control tqc popularized armand v feigenbaum harvard business review article book name stresses involvement departments addition


statistical quality control applied business strategy originated motorola lean six sigma l six sigma applied principles lean manufacturing lean enterprise originated wheat ''et al'' ref name wheatleaning ref project management project management quality control requires project manager project team inspect accomplished work ensure alignment project scope practice projects typically dedicated quality control team focuses area ref name roseproject ref see also analytical quality control corrective preventative action capa eight dimensions quality first article


inspection fai good automated manufacturing practice gamp good manufacturing practice quality assurance quality management framework standard operating procedure sop qa qc references reading external links http wwwastmorg standards quality control standardshtml astm quality control standards design x statistical process control quality management


'''quality control''' process maintaining proper standards manufacturing '''quality control''' may also refer analytical quality control ''quality control'' album album jurassic quality control title track quality control music american record label ''quality control control streets volume '' compilation album quality control music song ''summer girl'' fifth lp smash mouth


women 's army corps associated national security avoiding conversations war work'''security''' freedom resilience potential harm unwanted coercive change caused others beneficiaries technically referents security may persons social groups objects institutions ecosystems entity phenomenon vulnerable unwanted change refugees fleeing war insecurity iraq syria arrive lesbos island supported spanish volunteers security mostly refers protection hostile forces wide range senses example absence harm eg freedom

Applied science
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Security


want presence essential good eg food security resilience potential damage harm eg secure foundations secrecy eg secure telephone line containment eg secure room cell state mind eg emotional security term also used refer acts systems whose purpose may provide security eg security companies security forces security guard cyber security systems security cameras remote guarding security physical also '''virtual''' etymology word 'secure' entered english language


th century ref name derived latin ' 'securus'' meaning freedom anxiety ' 'se'' without ''cura'' care anxiety ref name ref overview referent security referent focus security policy discourse example referent may potential beneficiary victim security policy system security referents may persons social groups objects institutions ecosystems phenomenon vulnerable unwanted change forces environment ref name barry buzan ole w ver jaap de wilde ''security new framework analysis'' boulder lynne rienner publishers


p ref referent question may combine many referents way example nation state composed many individual citizens ref name ref context security context relationships security referent environment ref name perspective security insecurity depend first whether environment beneficial hostile referent also capable referent responding environment order survive thrive ref name capabilities means referent provides security provided


vary widely include example ''coercive capabilities'' including capacity project coercive power environment eg aircraft carrier handgun firearms ''protective systems'' eg lock fence wall antivirus software air defence system armour ''warning systems'' eg alarm radar ''diplomatic social action'' intended prevent insecurity developing eg conflict prevention transformation strategies ''policy'' intended develop lasting economic physical ecological conditions security eg economic reform ecological protection progressive demilitarization militarization effects action intended provide security may multiple effects example action may wide benefit


enhancing security several security referents context alternatively action may effective temporarily benefit one referent expense another entirely ineffective counterproductive contested approaches approaches security contested subject debate example debate national security strategies argue security depends principally developing protective coercive capabilities order protect security referent hostile environment potentially project power environment dominate point strategic supremacy others argue


security depends principally building conditions equitable relationships develop partly reducing antagonism actors ensuring fundamental needs met also differences interest negotiated effectively ref name border security vehicle us canadian border contexts security examples table shows main domains security concerns prominent '''it realm''' communications security computer security internet security application security data security digital security information security network security endpoint security'''physical realm''' airport security corporate security food security environmental security home security infrastructure security physical security port security supply


chain security security bag security print border security security seal '''political''' national security public security homeland security internal security international security human security '''monetary''' economic security financial security social security range security contexts illustrated following examples alphabetical order computer security computer security also known cybersecurity security refers security computing devices computers smartphones well computer networks private public networks internet field growing importance due increasing reliance computer systems societies concerns protection


hardware software data people also procedures systems accessed means computer security include physical security systems security information held corporate security corporate security refers resilience corporations espionage theft damage threats security corporations become complex reliance systems increased physical presence become highly distributed across several countries including environments may rapidly become hostile themsecurity checkpoint entrance delta air lines corporate headquarters


atlanta x ray machines metal detectors used control allowed pass airport security perimeter security checkpoint entrance shopping mall jakarta indonesia ecological security ecological security also known environmental security refers integrity ecosystems biosphere particularly relation capacity sustain diversity life forms including human life security ecosystems attracted greater attention impact ecological damage humans grown graffiti ecological security belarus food security food security refers


ready supply access safe nutritious food food security gaining importance world 's population grown productive land diminished overuse climate change climate change affecting global agriculture food security home security home security normally refers security systems used property used dwelling commonly including doors locks alarm systems lighting fencing personal security practices ensuring doors locked alarms activated windows closed etc security spikes protect gated community east end london human security


boys play among bombed ruins gaza city human security emerging paradigm response traditional emphasis right nation states protect focused primacy security people individuals communities concept supported united nations general assembly stressed right people live freedom dignity recognized individuals particular vulnerable people entitled freedom fear freedom want national security national security refers security nation state


change perceptions security without necessarily affecting security example visual signs security protections home advertises alarm system may deter intruder whether system functions properly similarly increased presence military personnel streets city terrorist attack may help reassure public whether diminishes risk attacks security concepts examples certain concepts recur throughout different fields security access control selective restriction access place resource assurance expression confidence


security measure perform expected authorization function specifying access rights privileges resources related information security computer security general access control particular countermeasure means preventing act system intended effect defense depth school thought holding wider range security measures enhance security exploit noun means capitalizing vulnerability security system usually cyber security system identity management enables right individuals access right resources right


times right reasons resilience degree person community nation system able resist adverse external forces risk possible event could lead damage harm loss security management identification organization 's assets including people buildings machines systems information assets followed development documentation implementation policies procedures protecting assets threat potential source harm vulnerability degree something may changed usually unwanted manner external forces see also peace safety security increase


security risk security convergence references external links prevention law enforcement


popular puzzle rubik 's cube invented ern rubik used illustration permutation groups see rubik 's cube group mathematics abstract algebra '''group theory''' studies algebraic structures known groups concept group central abstract algebra well known algebraic structures rings fields vector spaces seen groups endowed additional operations axioms groups recur throughout mathematics methods group theory influenced many parts algebra linear algebraic groups lie groups two branches group theory

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experienced advances become subject areas right various physical systems crystals hydrogen atom may modelled symmetry groups thus group theory closely related representation theory many important applications physics chemistry materials science group theory also central public key cryptography early history group theory dates th century one important mathematical achievements th century collaborative effort taking journal pages mostly published culminated


complete classification finite simple groups main classes groups range groups considered gradually expanded finite permutation groups special examples matrix groups abstract groups may specified presentation generators relations permutation groups first class groups undergo systematic study permutation groups given set ''x'' collection ''g'' bijections ''x'' known ''permutations'' closed compositions inverses ''g'' group acting ''x'' ''x'' consists ''n'' elements ''g'' consists


''all'' permutations ''g'' symmetric group sub ''n'' sub general permutation group ''g'' subgroup symmetric group ''x'' early construction due cayley exhibited group permutation group acting means left regular representation many cases structure permutation group studied using properties action corresponding set example way one proves alternating group sub ''n'' sub simple ie admit proper normal subgroups fact plays key role


''n'' radicals matrix groups next important class groups given ''matrix groups'' linear groups ''g'' set consisting invertible matrices given order ''n'' field ''k'' closed products inverses group acts ''n'' dimensional vector space ''k'' sup ''n'' sup linear transformations action makes matrix groups conceptually similar permutation groups geometry action may usefully exploited establish properties group ''g'' transformation groups permutation groups matrix groups special cases transformation groups


groups act certain space ''x'' preserving inherent structure case permutation groups ''x'' set matrix groups ''x'' vector space concept transformation group closely related concept symmetry group transformation groups frequently consist ''all'' transformations preserve certain structure theory transformation groups forms bridge connecting group theory differential geometry long line research originating lie klein considers group actions manifolds homeomorphisms diffeomorphisms groups may discrete continuous abstract


groups groups considered first stage development group theory concrete realized numbers permutations matrices late nineteenth century idea abstract group set operations satisfying certain system axioms began take hold typical way specifying abstract group presentation ''generators relations'' math g langle r rangle math significant source abstract groups given construction ''factor group'' quotient group ''g'' ''h'' group ''g''


normal subgroup ''h'' class groups algebraic number fields among earliest examples factor groups much interest number theory group ''g'' permutation group set ''x'' factor group ''g'' ''h'' longer acting ''x'' idea abstract group permits one worry discrepancy change perspective concrete abstract groups makes natural consider properties groups independent particular realization modern language invariant isomorphism well classes group


groups mainstays differential geometry unitary representation theory certain classification questions cannot solved general approached resolved special subclasses groups thus compact connected lie groups completely classified fruitful relation infinite abstract groups topological groups whenever group '' '' realized lattice topological group ''g'' geometry analysis pertaining ''g'' yield important results '' '' comparatively recent trend theory finite groups exploits connections compact topological groups profinite groups example


single ''p'' adic analytic group ''g'' family quotients finite ''p'' groups various orders properties ''g'' translate properties finite quotients branches group theory finite group theory twentieth century mathematicians investigated aspects theory finite groups great depth especially local theory finite groups theory solvable nilpotent groups consequence complete classification finite simple groups achieved meaning simple groups finite groups built known second


properties finite groups thus play role subjects theoretical physics chemistry representation groups saying group ''g'' ''acts'' set ''x'' means every element ''g'' defines bijective map set ''x'' way compatible group structure ''x'' structure useful restrict notion representation ''g'' vector space ''v'' group homomorphism math rho g operatorname gl v math gl ''v'' consists invertible linear transformations ''v'' words every group element ''g''


assigned automorphism '' '' ''g'' ''h'' ''g'' definition understood two directions give rise whole new domains mathematics one hand may yield new information group ''g'' often group operation ''g'' abstractly given via '' '' corresponds multiplication matrices explicit hand given well understood group acting complicated object simplifies study object question example ''g'' finite known ''v''


decomposes irreducible parts parts turn much easily manageable whole ''v'' via schur 's lemma given group ''g'' representation theory asks representations ''g'' exist several settings employed methods obtained results rather different every case representation theory finite groups representations lie groups two main subdomains theory totality representations governed group 's characters example fourier polynomials interpreted characters u group complex numbers absolute value '' '' acting


''l'' sup sup space periodic functions lie theory lie group group also differentiable manifold property group operations compatible smooth structure lie groups named sophus lie laid foundations theory continuous transformation groups term ''groupes de lie'' first appeared french thesis lie 's student arthur tresse page lie groups represent best developed theory continuous symmetry mathematical objects structures makes indispensable tools many parts contemporary mathematics well


assumptions satisfied example finitely generated groups finitely presented groups ie addition relations finite area makes use connection graphs via fundamental groups example one show every subgroup free group free several natural questions arising giving group presentation ''word problem'' asks whether two words effectively group element relating problem turing machines one show general algorithm solving task another generally harder algorithmically insoluble problem


correspond group elements edges correspond right multiplication group given two elements one constructs word metric given length minimal path elements theorem milnor svarc says given group ''g'' acting reasonable manner metric space ''x'' example compact manifold ''g'' quasi isometric ie looks similar distance space ''x'' connection groups symmetry given structured object ''x'' sort symmetry mapping object onto preserves


structure occurs many cases example ''x'' set additional structure symmetry bijective map set giving rise permutation groups object ''x'' set points plane metric structure metric space symmetry bijection set preserves distance pair points isometry corresponding group called isometry group ''x'' instead angles preserved one speaks conformal maps conformal maps give rise kleinian


symmetry group automorphism group object question applications group theory applications group theory abound almost structures abstract algebra special cases groups rings example viewed abelian groups corresponding addition together second operation corresponding multiplication therefore group theoretic arguments underlie large parts theory entities galois theory galois theory uses groups describe symmetries roots polynomial precisely automorphisms algebras generated roots fundamental theorem galois theory provides


way classifying spaces groups finally name torsion subgroup infinite group shows legacy topology group theory '''c''' '''c''' '''z''' '' '''''z''' '' '' parameter living upper half plane algebraic geometry algebraic geometry likewise uses group theory many ways abelian varieties introduced presence group operation yields additional information makes varieties particularly accessible also often serve test new conjectures one dimensional case namely elliptic curves studied particular detail theoretically


practically intriguing another direction toric varieties algebraic varieties acted torus toroidal embeddings recently led advances algebraic geometry particular resolution singularities algebraic number theory algebraic number theory makes uses groups important applications example euler 's product formula math begin align sum n geq frac n prod p text prime frac p end align math captures fact integer decomposes unique way primes failure statement general rings gives rise class groups regular primes feature kummer 's treatment fermat 's last


set theory transformational theory models musical transformations elements mathematical group physics physics groups important describe symmetries laws physics seem obey according noether 's theorem every continuous symmetry physical system corresponds conservation law system physicists interested group representations especially lie groups since representations often point way possible physical theories examples use groups physics include standard model gauge theory lorentz group poincar group group theory used


elements point line plane respect symmetry operation carried symmetry operations molecule determine specific point group molecule water molecule symmetry axis chemistry five important symmetry operations identity operation '''e ''' rotation operation proper rotation '''c sub ''n'' sub ''' reflection operation ''' ''' inversion '''i''' rotation reflection operation improper rotation '''s sub ''n'' sub ''' identity operation '''e''' consists leaving molecule equivalent number full rotations around axis symmetry


molecules whereas symmetry group chiral molecule consists identity operation identity operation characteristic every molecule even symmetry rotation around axis '''c sub ''n'' sub ''' consists rotating molecule around specific axis specific angle rotation angle ''n'' ''n'' integer rotation axis example water molecule rotates around axis passes oxygen atom hydrogen atoms configuration started case


started plane perpendicular principal axis rotation called ''' sub ''h'' sub ''' horizontal planes contain principal axis rotation labeled vertical ''' sub ''v'' sub ''' dihedral ''' sub ' 'd'' sub ''' inversion complex operation point moves center molecule position opposite original position far central point started many molecules seem first glance inversion center example methane tetrahedral molecules lack inversion symmetry see hold


methane model two hydrogen atoms vertical plane right two hydrogen atoms horizontal plane left inversion results two hydrogen atoms horizontal plane right two hydrogen atoms vertical plane left inversion therefore symmetry operation methane orientation molecule following inversion operation differs original orientation last operation improper rotation rotation reflection operation '''s sub ''n'' sub ''' requires rotation ''n'' followed reflection plane perpendicular axis


rotation cryptography large groups prime order constructed elliptic curve cryptography serve public key cryptography cryptographical methods kind benefit flexibility geometric objects hence group structures together complicated structure groups make discrete logarithm hard calculate one earliest encryption protocols caesar 's cipher may also interpreted easy group operation cryptographic schemes use groups way particular diffie hellman key exchange uses finite cyclic groups term group based cryptography refers mostly cryptographic protocols use infinite


nonabelian groups braid group cyclic group '''z''' sub sub underlies caesar 's cipher history group theory three main historical sources number theory theory algebraic equations geometry number theoretic strand begun leonhard euler developed gauss 's work modular arithmetic additive multiplicative groups related quadratic fields early results permutation groups obtained lagrange ruffini abel quest general solutions polynomial equations high degree variste galois coined term group established connection known galois theory nascent theory


groups field theory geometry groups first became important projective geometry later non euclidean geometry felix klein 's erlangen program proclaimed group theory organizing principle geometry galois first employ groups determine solvability polynomial equations arthur cayley augustin louis cauchy pushed investigations creating theory permutation groups second historical source groups stems geometrical situations attempt come grips possible geometries euclidean hyperbolic projective geometry using group theory felix klein initiated erlangen


programme sophus lie started using groups called lie groups attached analytic problems thirdly groups first implicitly later explicitly used algebraic number theory different scope early sources resulted different notions groups theory groups unified starting around since impact group theory ever growing giving rise birth abstract algebra early th century representation theory many influential spin domains classification finite simple groups vast body work mid th


century classifying finite simple groups see also list group theory topics examples groups notes references references shows advantage generalising group groupoid introductory undergraduate text spirit texts gallian herstein covering groups rings integral domains fields galois theory free downloadable pdf open source gfdl license conveys practical value group theory explaining points symmetries physics sciences ronan ''symmetry monster'' oxford university press lay readers describes quest find basic


building blocks finite groups standard contemporary reference inexpensive fairly readable somewhat dated emphasis style notation external links http www historymcsst andrewsacuk history histtopics abstract groupshtml history abstract group concept https archivetoday http wwwbangoracuk rbrown hdaweb htm higher dimensional group theory presents view group theory level one theory extends dimensions applications homotopy theory higher dimensional nonabelian methods local global problems http plusmathsorg issue package indexhtml plus teacher student package group theory package brings together articles group theory ''plus'' online mathematics magazine produced millennium mathematics project


university cambridge exploring applications recent breakthroughs giving explicit definitions examples groups detailed exposition contemporaneous understanding group theory early researcher field ml


'''plastic surgery''' surgical specialty involving restoration reconstruction alteration human body divided two main categories '' 'reconstructive surgery''' '''cosmetic surgery''' reconstructive surgery includes craniofacial surgery hand surgery microsurgery treatment burns reconstructive surgery aims reconstruct part body improve functioning cosmetic aesthetic surgery aims improving appearance etymology word ''plastic'' ''plastic surgery'' means reshaping comes greek ''plastik '' ''tekhn '' art modelling malleable flesh meaning english

Applied science
Medicine and health
Surgery
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name ref early trauma surgery textbook named american egyptologist edwin smith ref name reconstructive surgery techniques carried india bc ref name ep msn encarta http wwwencartaes encyclopedia plastic surgeryhtml ''plastic surgery'' ref sushruta physician made contributions field plastic cataract surgery th century bc ref name dwivedi dwivedi dwivedi girish dwivedi shridhar http medindnicin iae iaet p pdf ''history medicine sushruta clinician teacher par excellence'' national informatics centre government india ref sushruta 's developments preserved book ''sushruta samhita'' roman scholar aulus cornelius celsus recorded surgical techniques including plastic surgery


first century ad romans also performed plastic cosmetic surgery using simple techniques repairing damaged ears around st century bc religious reasons dissect either human beings animals thus knowledge based entirety texts greek predecessors notwithstanding aulus cornelius celsus left surprisingly accurate anatomical descriptions instance studies genitalia skeleton special interest plastic surgery indian medical works sushruta charaka originally sanskrit translated


arabic language abbasid caliphate ad ref name locka lock stephen etc ''the oxford illustrated companion medicine'' usa oxford university press '' page '' ref arabic translations made way europe via intermediaries ref name locka italy branca family sicily gaspare tagliacozzi bologna became familiar techniques sushruta ref name locka illustration th century nose reconstruction method poona performed indian potter gentleman magazine british physicians traveled india see rhinoplasties performed indian methods ref name lock lock stephen etc ''the oxford illustrated companion medicine'' usa oxford


university press '' page '' ref reports indian rhinoplasty performed kumhar vaidya published ''gentleman 's magazine'' ref name lock joseph constantine carpue spent years india studying local plastic surgery methods ref name lock carpue able perform first major surgery western world year ref name lock lock stephen etc ''the oxford illustrated companion medicine'' usa oxford university press '' page '' ref instruments described ''sushruta samhita'' modified western world ref name lock sabuncu 's book description classification hypospadias informative


jacques joseph german orthopaedic trained surgeon published first account reduction rhinoplasty jacques joseph published ''nasenplastik und sonstige gesichtsplastik'' development modern techniques walter yeo sailor injured battle jutland assumed received plastic surgery photograph shows immediately following right flap surgery sir harold gillies healing left father modern plastic surgery generally considered sir harold gillies new zealand otolaryngologist working london developed many techniques modern facial surgery caring soldiers suffering


disfiguring facial injuries first world war world war worked medical minder royal army medical corps working renowned french oral maxillofacial surgeon hippolyte morestin skin graft persuaded army 's chief surgeon arbuthnot lane establish facial injury ward cambridge military hospital aldershot later upgraded new hospital facial repairs sidcup gillies colleagues developed many techniques plastic surgery operations performed men mostly soldiers facial injuries usually


surgical instrument named kilner cheek retractor went queen mary 's hospital roehampton mowlem went st albans mcindoe consultant raf moved recently rebuilt queen victoria hospital east grinstead sussex founded centre plastic jaw surgery treated deep burn serious facial disfigurement loss eyelids typical caused aircrew burning fuel mcindoe often recognized developing new techniques treating badly burned faces hands also recognising importance


rehabilitation casualties particularly social reintegration back normal life disposed convalescent uniforms let patients use service uniforms instead help two friends neville elaine blond also convinced locals support patients invite homes mcindoe kept referring boys staff called boss maestro important work included development walking stalk skin graft discovery immersion saline promoted healing well improving survival rates victims


component plastic surgery includes facial body aesthetic surgery plastic surgeons use cosmetic surgical principles reconstructive surgical procedures well isolated operations improve overall appearance burn surgery burn surgery generally takes place two phases acute burn surgery treatment immediately burn reconstructive burn surgery takes place burn wounds healed craniofacial surgery craniofacial surgery divided pediatric adult craniofacial surgery pediatric craniofacial surgery mostly revolves around treatment congenital anomalies craniofacial skeleton soft tissues cleft lip palate microtia craniosynostosis


pediatric fractures adult craniofacial surgery deals mostly reconstructive surgeries trauma cancer revision surgeries along orthognathic surgery facial feminization surgery craniofacial surgery important part plastic surgery training programs training subspecialisation obtained via craniofacial fellowship craniofacial surgery also practiced maxillofacial surgeons ethnic plastic surgery ethnic plastic surgery plastic surgery performed change ethnic attributes often considered used way passing hand surgery hand surgery concerned acute injuries chronic diseases hand wrist correction congenital malformations


upper extremities peripheral nerve problems brachial plexus injuries carpal tunnel syndrome hand surgery important part training plastic surgery well microsurgery necessary replant amputated extremity hand surgery field also practiced orthopedic surgeons general surgeons scar tissue formation surgery problematic delicate hand causing loss dexterity digit function severe enough cases surgery women 's hands order correct perceived flaws create perfect engagement ring photo microsurgery microsurgery generally


concerned reconstruction missing tissues transferring piece tissue reconstruction site reconnecting blood vessels popular subspecialty areas breast reconstruction head neck reconstruction hand surgery replantation brachial plexus surgery pediatric plastic surgery children often face medical issues different experiences adult patient many birth defects syndromes present birth best treated childhood pediatric plastic surgeons specialize treating conditions children conditions commonly treated pediatric plastic surgeons include craniofacial anomalies syndactyly webbing fingers toes polydactyly excess fingers toes


birth cleft lip palate congenital hand deformities prison plastic surgery plastic surgery performed incarcerated population order affect recidivism rate practice instituted early th century lasted mid separate surgery performed medical need techniques procedures plastic surgery transfer skin tissue skin grafting common procedure skin grafts derived recipient donors autografts taken recipient absent deficient natural tissue alternatives cultured sheets epithelial cells ''in


vitro'' synthetic compounds integra consists silicone bovine tendon collagen glycosaminoglycans allografts taken donor species xenografts taken donor different species usually good results would expected plastic surgery emphasize careful planning incisions fall within line natural skin folds lines appropriate choice wound closure use best available suture materials early removal exposed sutures wound held closed buried sutures reconstructive surgery navy doctors perform reconstructive surgery


breast reduction men decreased percent performed common reconstructive surgical procedures include breast reconstruction mastectomy treatment cancer cleft lip palate surgery contracture surgery burn survivors creating new outer ear one congenitally absent plastic surgeons use microsurgery transfer tissue coverage defect local tissue available free flaps skin muscle bone fat combination may removed body moved another site body reconnected


blood supply suturing arteries veins small millimeters diameter cosmetic surgery procedures cosmetic surgery voluntary elective surgery performed normal parts body purpose improving person 's appearance removing signs aging nearly million cosmetic procedures performed united states alone number cosmetic procedures performed united states almost doubled since start century cosmetic procedures performed women nearly


society plastic surgeons asps estimates cosmetic procedures performed patients years age younger us compared approx significant encourages younger people continue procedures later life increased use cosmetic procedures crosses racial ethnic lines us increases seen among african americans asian americans hispanic americans well caucasian americans uk newspaper articles used term plastic surgery context cosmetic surgery significant shows


frequency western world portrays cosmetic surgery asia cosmetic surgery become popular countries china india become asia 's biggest cosmetic surgery markets south korea also rising popularity due expertise facial bone surgeries first publication team south korean surgeons facial bone contouring surgeries published illustrating various surgery methods used facial bone contouring surgeries ref name ref plastic surgery increasing slowly rising according annual plastic surgery procedural statistics million surgical


including asian blepharoplasty phalloplasty penile surgery construction reconstruction penis sometimes artificial modification penis surgery often cosmetic purposes mammoplasty breast augmentations breast implant boob job augmentation breasts means fat grafting saline silicone gel prosthetics initially performed women micromastia reduction mammoplasty breast reduction removal skin glandular tissue done reduce back shoulder pain women gigantomastia men gynecomastia mastopexy breast lift lifting reshaping breasts make less saggy often weight loss


enhancement buttocks using silicone implants fat grafting brazilian butt lift fat transferred areas body cryolipolysis refers medical device used destroy fat cells principle relies controlled cooling non invasive local reduction fat deposits reshape body contours cryoneuromodulation treatment superficial subcutaneous tissue structures using gaseous nitrous oxide including temporary wrinkle reduction temporary pain reduction treatment dermatologic conditions focal cryo treatment tissue calf augmentation done silicone implants fat transfer add bulk calf muscles labiaplasty surgical reduction reshaping


labia lip augmentation alter appearance lips increasing fullness surgical enlargement lip implants nonsurgical enhancement injectable fillers cheiloplasty surgical reconstruction lip rhinoplasty nose job reshaping nose sometimes used correct breathing impaired structural defects otoplasty ear surgery ear pinning reshaping ear often done pinning protruding ear closer head rhytidectomy face lift removal wrinkles signs aging face neck lift tightening lax tissues neck procedure often combined facelift lower


face rejuvenation browplasty brow lift forehead lift elevates eyebrows smooths forehead skin midface lift cheek lift tightening cheeks genioplasty augmentation chin individual 's bones use implant usually silicone suture soft tissue ref name mentoplasty surgery chin involve either enhancing reducing size chin enhancements achieved use facial implants reduction chin involved reducing size chin bone cheek augmentation cheek implant implants cheek orthognathic surgery altering upper lower


jaw bones osteotomy correct jaw alignment issues correct teeth alignment fillers injections collagen fat tissue filler injections hyaluronic acid brachioplasty arm lift reducing excess skin fat underarm elbow laser skin rejuvenation laser resurfacing lessening depth facial pores exfoliation dead damaged skin cells liposuction suction lipectomy removal fat deposits traditional suction technique ultrasonic energy aid fat removal zygoma reduction plasty reducing facial width performing osteotomy resecting part zygomatic bone arch ref name


jaw reduction reduction mandible angle smooth angular jaw creating slim jaw ref name buccal fat extraction extraction buccal pads body contouring removal excess skin fat numerous areas body restoring appearance skin elasticity remaining skin surgery prominent undergone significant weight loss resulting excess sagging skin present around areas body skin losses elasticity condition called elastosis stretched past capacity unable recoil back


bones depleted articular cartilage casing development within field occurred time synthetic forms hyaluronic acid created playing roles forms cosmetic surgery facial augmentation micropigmentation creation permanent makeup using natural pigments places eyes create effect eye shadow lips creating lipstick cheek bones create blush like look pigment inserted beneath skin using machine injects small needle fast rate carrying pigment skin creating


lasting colouration desired area popular surgeries botox liposuction eyelid surgery breast implants nose jobs facelifts complications risks reversals surgery risks common complications cosmetic surgery includes hematoma nerve damage infection scarring implant failure organ damage breast implants many complications including rupture study augmentation mammaplasty patients eisenberg reported overfilling saline breast implants significantly reduced rupture deflation rate years post implantation ref name eisenberg ref fda stated one five patients received implants breast augmentation need


removed within years implantation psychological disorders though media advertising play large role influencing many people 's lives making people believe plastic surgery acceptable course change identities liking researchers believe plastic surgery obsession linked psychological disorders like body dysmorphic disorder exists correlation sufferers bdd predilection toward cosmetic plastic surgery order correct perceived defect appearance ref name pmjbdd ref bdd disorder resulting sufferer becoming preoccupied regard defects


bodies faces alternatively slight physical anomaly person 's concern markedly excessive ref name pmjbdd people suffer body dysmorphic disorder united states patients seeing dermatologist cosmetic surgeons disorder half patients disorder cosmetic surgery performed pleased aesthetic outcome bdd lead suicide sufferers many bdd seek cosmetic surgery procedures treat bdd ultimately worsen problem psychological root problem


usually unidentified therefore causing treatment even difficult say fixation obsession correction area could sub disorder anorexia muscle dysmorphia increased use body facial reshaping applications snapchat facetune identified potential triggers bdd recently phenomenon referred 'snapchat dysmorphia' appeared describe people request surgery resemble edited version appear snapchat filters protest detrimental trend instagram banned augmented reality ar filters


depict promote cosmetic surgery cases people whose physicians refuse perform surgeries turned plastic surgery injecting running extreme safety risks see also biomaterial body modification dental trauma ethnic plastic surgery ''plastic reconstructive surgery'' scalp reconstruction list plastic surgery flaps cosmetic surgery australia references reading external links '' https wwwstatistacom statistics leading countries total number cosmetic procedures countries largest total number cosmetic procedures '' statista medical specialties cosmetic surgery cosmetic industry


'''data mining''' process extracting discovering patterns large data sets involving methods intersection machine learning statistics database systems ref name acm data mining interdisciplinary subfield computer science statistics overall goal extract information intelligent methods data set transform information comprehensible structure use ref name acm ref ref name brittanica ref ref name elements ref data mining analysis step knowledge discovery databases process kdd ref name fayyad aside raw analysis step also involves database data management aspects data

Formal science
Computer science
Social sciences
Data mining


pre processing model inference considerations interestingness metrics complexity considerations post processing discovered structures visualization online updating ref name acm term data mining misnomer goal extraction patterns knowledge large amounts data extraction ''mining'' data ref name han kamber ref also buzzword frequently applied form large scale data information processing collection extraction warehousing analysis statistics well application computer decision support system including artificial intelligence eg machine learning business intelligence book ''data mining practical machine learning tools


techniques java'' ref name witten ref covers mostly machine learning material originally named ''practical machine learning'' term ' 'data mining'' added marketing reasons often general terms ''large scale'' ' 'data analysis'' ''analytics'' referring actual methods ''artificial intelligence'' ''machine learning'' appropriate actual data mining task semi automatic automatic analysis large quantities data extract previously unknown interesting patterns groups data records cluster analysis unusual records anomaly detection dependencies association rule mining sequential pattern mining usually involves using


database techniques spatial indices patterns seen kind summary input data may used analysis example machine learning predictive analytics example data mining step might identify multiple groups data used obtain accurate prediction results decision support system neither data collection data preparation result interpretation reporting part data mining step belong overall kdd process additional steps difference data analysis


data mining data analysis used test models hypotheses dataset eg analyzing effectiveness marketing campaign regardless amount data contrast data mining uses machine learning statistical models uncover clandestine hidden patterns large volume data related terms ' 'data dredging'' ' 'data fishing'' ' 'data snooping'' refer use data mining methods sample parts larger population data set may small reliable statistical inferences made validity patterns


discovered methods however used creating new hypotheses test larger data populations etymology statisticians economists used terms like ' 'data fishing'' ' 'data dredging'' refer considered bad practice analyzing data without priori hypothesis term data mining used similarly critical way economist michael lovell article published ''review economic studies'' lovell indicates practice masquerades variety aliases ranging experimentation positive fishing snooping negative term ' 'data mining''


appeared around database community generally positive connotations short time phrase database mining used since trademarked hnc san diego based company pitch database mining workstation ref name mena ref researchers consequently turned ' 'data mining'' terms used include ' 'data archaeology'' ''information harvesting'' ''information discovery'' ''knowledge extraction'' etc gregory piatetsky shapiro coined term knowledge discovery databases first workshop topic http wwwkdnuggetscom meetings kdd kdd term became popular ai machine learning community however term data mining became popular


business press communities currently terms ' 'data mining'' ''knowledge discovery'' used interchangeably academic community major forums research started first international conference data mining knowledge discovery kdd started montreal aaai sponsorship co chaired usama fayyad ramasamy uthurusamy year later usama fayyad launched journal kluwer called data mining knowledge discovery founding editor chief later started sigkdd newsletter sigkdd explorations ref name sigkdd explorations ref kdd international conference became primary highest quality conference data mining


acceptance rate research paper submissions journal ''data mining knowledge discovery'' primary research journal field background manual extraction patterns data occurred centuries early methods identifying patterns data include bayes' theorem regression analysis proliferation ubiquity increasing power computer technology dramatically increased data collection storage manipulation ability data sets grown size complexity direct hands data analysis increasingly augmented indirect automated data processing aided discoveries computer science specially


field machine learning neural networks cluster analysis genetic algorithms decision trees decision rules support vector machines data mining process applying methods intention uncovering hidden patterns ref name kantardzic ref large data sets bridges gap applied statistics artificial intelligence usually provide mathematical background database management exploiting way data stored indexed databases execute actual learning discovery algorithms efficiently allowing methods applied ever larger data sets process ''knowledge


discovery databases kdd process'' commonly defined stages selection pre processing transformation ''data mining'' interpretation evaluation ref name fayyad exists however many variations theme cross industry standard process data mining crisp dm defines six phases business understanding data understanding data preparation modeling evaluation deployment simplified process pre processing data mining results validation polls conducted show crisp dm methodology leading methodology used data miners


data mining standard named polls semma however times many people reported using crisp dm several teams researchers published reviews data mining process models ref name kurgan lukasz kurgan petr musilek http journalscambridgeorg action displayabstractfrompage online aid survey knowledge discovery data mining process models ''the knowledge engineering review'' volume issue march pp nbsp cambridge university press new york ref azevedo santos conducted comparison crisp dm semma ref name azevedosantos azevedo santos f http wwwiadisnet dl final uploads p pdf kdd semma crisp dm parallel overview proceedings iadis european conference


data mining pp nbsp ref pre processing data mining algorithms used target data set must assembled data mining uncover patterns actually present data target data set must large enough contain patterns remaining concise enough mined within acceptable time limit common source data data mart data warehouse pre processing essential analyze multivariate data sets data mining target set cleaned data cleaning removes observations containing noise missing data data mining data


showing close link best word winning spelling bee competition number people united states killed venomous spiders similarity trends obviously coincidence data mining unintentionally misused produce results appear significant actually predict future behavior cannot reproduced new sample data bear little use often results investigating many hypotheses performing proper statistical hypothesis testing simple version problem machine learning known overfitting


problem arise different phases process thus train test split applicable may sufficient prevent happening ref name hawkins ref final step knowledge discovery data verify patterns produced data mining algorithms occur wider data set patterns found data mining algorithms necessarily valid common data mining algorithms find patterns training set present general data set called overfitting overcome evaluation uses


test set data data mining algorithm trained learned patterns applied test set resulting output compared desired output example data mining algorithm trying distinguish spam legitimate emails would trained training set sample e mails trained learned patterns would applied test set e mails ''not'' trained accuracy patterns measured many e mails correctly classify several statistical methods may used evaluate


published biannual academic journal titled sigkdd explorations computer science conferences data mining include cikm conference acm conference information knowledge management european conference machine learning principles practice knowledge discovery databases kdd conference acm sigkdd conference knowledge discovery data mining data mining topics also present many data management database conferences icde conference sigmod conference international conference large data bases standards efforts define standards data mining process example european cross industry standard process


data mining crisp dm java data mining standard jdm development successors processes crisp dm jdm active stalled since jdm withdrawn without reaching final draft exchanging extracted models particular use predictive analytics key standard predictive model markup language pmml xml based language developed data mining group dmg supported exchange format many data mining applications name suggests covers prediction models particular data mining task high


importance business applications however extensions cover example subspace clustering proposed independently dmg notable uses data mining used wherever digital data available today notable examples data mining found throughout business medicine science surveillance privacy concerns ethics term data mining may ethical implications often associated mining information relation peoples' behavior ethical otherwise ways data mining used cases contexts raise questions regarding privacy legality ethics


particular data mining government commercial data sets national security law enforcement purposes total information awareness program advise raised privacy concerns data mining requires data preparation uncovers information patterns compromise confidentiality privacy obligations common way occur data aggregation data aggregation involves combining data together possibly various sources way facilitates analysis also might make identification private individual level data deducible otherwise apparent ref name nascio http wwwnascioorg publications documents nascio dataminingpdf ''think dig privacy implications data mining aggregation''


nascio research brief september ref data mining ''per se'' result preparation data purposes analysis threat individual 's privacy comes play data compiled cause data miner anyone access newly compiled data set able identify specific individuals especially data originally anonymous recommended aware following '''before''' data collected ref name nascio purpose data collection known data mining projects data


consequence edward snowden 's global surveillance disclosure increased discussion revoke agreement particular data fully exposed national security agency attempts reach agreement united states failed united kingdom particular cases corporations using data mining way target certain groups customers forcing pay unfairly high prices groups tend people lower socio economic status savvy ways exploited digital market places


individuals underscores necessity data anonymity data aggregation mining practices us information privacy legislation hipaa family educational rights privacy act ferpa applies specific areas law addresses use data mining majority businesses us controlled legislation copyright law situation europe european copyright database laws mining copyright works web mining without permission copyright owner legal database pure data europe


may copyright database rights may exist data mining becomes subject intellectual property owners' rights protected database directive recommendation hargreaves review led uk government amend copyright law allow content mining limitation exception uk second country world japan introduced exception data mining however due restriction information society directive uk exception allows content mining non commercial


purposes uk copyright law also allow provision overridden contractual terms conditions since also switzerland regulating data mining allowing research field certain conditions laid art swiss copyright act new article entered force st april european commission facilitated stakeholder discussion text data mining title licences europe focus solution legal issue licensing rather limitations exceptions led representatives universities researchers


libraries civil society groups open access publishers leave stakeholder dialogue may situation united states us copyright law particular provision fair use upholds legality content mining america fair use countries israel taiwan south korea content mining transformative supplant original work viewed lawful fair use example part google book settlement presiding judge case ruled google 's digitization project copyright books lawful


part transformative uses digitization project displayed one text data mining software free open source data mining software applications following applications available free open source licenses public access application source code also available carrot text search results clustering framework chemicalizeorg chemical structure miner web search engine elki university research project advanced cluster analysis outlier detection methods written java language gate natural language processing language engineering tool knime konstanz information miner user friendly comprehensive data analytics framework massive online analysis


moa real time big data stream mining concept drift tool java programming language mepx cross platform tool regression classification problems based genetic programming variant mlpack collection ready use machine learning algorithms written c language nltk natural language toolkit suite libraries programs symbolic statistical natural language processing nlp python language opennn open neural networks library orange component based data mining machine learning software suite written python language pspp data mining statistics software gnu project similar spss r


data mining experiments sas enterprise miner data mining software provided sas institute spss modeler data mining software provided ibm statistica data miner data mining software provided statsoft tanagra visualisation oriented data mining software also teaching vertica data mining software provided hewlett packard google cloud platform automated custom ml models managed google amazon sagemaker managed service provided amazon creating productionising custom ml models see also methods application domains application examples related topics information extracting information data opposed ''analyzing'' data see


resources international journal data warehousing mining references reading cabena peter hadjnian pablo stadler rolf verhees jaap zanasi alessandro ''discovering data mining concept implementation'' prentice hall ms chen j han ps yu http csnjueducn zhouzh zhouzhfiles course dm reading reading chen tkde pdf data mining overview database perspective ''knowledge data engineering ieee transactions'' feldman ronen sanger james ''the text mining handbook'' cambridge university press guo yike grossman robert editors ''high performance data mining scaling algorithms applications systems'' kluwer academic publishers han jiawei micheline kamber jian pei ''data mining concepts


techniques'' morgan kaufmann hastie trevor tibshirani robert friedman jerome ''the elements statistical learning data mining inference prediction'' springer liu bing ''web data mining exploring hyperlinks contents usage data'' springer nisbet robert elder john miner gary ''handbook statistical analysis data mining applications'' academic press elsevier poncelet pascal masseglia florent teisseire maguelonne editors october data mining patterns new methods applications ''information science reference'' tan pang ning steinbach michael kumar vipin ''introduction data mining'' theodoridis sergios koutroumbas konstantinos ''pattern recognition'' th edition academic press weiss sholom


indurkhya nitin ''predictive data mining'' morgan kaufmann see also free weka software ye nong ''the handbook data mining'' mahwah nj lawrence erlbaum external links formal sciences


'''sex education''' also known '' 'sexual education''' '' 'sexuality''' '''education''' '' 'sex ed''' instruction issues relating human sexuality including emotional relations responsibilities human sexual anatomy sexual activity sexual reproduction age consent reproductive health reproductive rights sexual health safe sex birth control sex education includes issues known comprehensive sex education often opposed abstinence sex education focuses sexual abstinence sex education may provided parents caregivers part school programs public health campaigns countries

Social science
Sociology
Sexology
Sex education


known relationships sexual health education history many cultures discussion sexual issues traditionally considered taboo adolescents given information sexual matters instruction given traditionally left child 's parents often put marriage however late th century progressive education movement led introduction sex education social hygiene north american school curricula introduction school based sex education ref name tupper ref despite early inroads school based sex education information


sexual matters mid th century obtained informally friends media much information deficient dubious value especially period following puberty curiosity sexual matters acute deficiency heightened increasing incidence teenage pregnancies particularly western countries part country 's efforts reduce pregnancies programs sex education introduced initially strong opposition parent religious groups outbreak aids given new sense urgency sex education many african


countries aids epidemic levels see hiv aids africa sex education seen scientists vital public health strategy international organizations planned parenthood consider broad sex education programs global benefits controlling risk overpopulation advancement women 's rights see also reproductive rights use mass media campaigns sometimes resulted high levels awareness coupled essentially superficial knowledge hiv transmission ref name newapproach ref according siecus sexuality information education council united states adults surveyed support sexuality


education high school support junior high school fact parents junior high school students parents secondary school students believe sex education school makes easier talk adolescents sex also adolescents report want talk parents sex comprehensive school sex education furthermore study conducted mathematica policy research behalf us department health human services found abstinence marriage programs ineffective definitions leepson sees


information family planning reproduction fertilization conception development embryo fetus childbirth plus information aspects one 's sexuality including body image sexual orientation sexual pleasure values decision making communication dating relationships sexually transmitted infections stis avoid birth control methods ref name delamare various aspects sex education considered appropriate school depending age students children comprehend particular point time rubin kindendall expressed sex education merely topics reproduction teaching babies


conceived born instead far richer scope goal helping children incorporate sex meaningfully present future life provide basic understanding virtually every aspect sex time reach full maturity evidence evidence shows combination comprehensive sex education access birth control appears decrease rates unintended pregnancies among teenagers meta analysis compared comprehensive sex education programs abstinence programs found abstinence programs reduce likelihood pregnancy rather may increased


numerous studies show curricula providing accurate information condoms contraception lead reductions risky behaviors reported young people well reductions unintended pregnancies stis ref name unfpaorg ref programs teach abstinence shown effective ref name unfpaorg according unfpa review found 'gender focused' curricula meaning curricula integrate gender equality learning material substantially effective reducing risky behaviors programmes consider gender ref name unfpaorg research also shown delay sexual initiation use condoms


practice contraception result young people adopting egalitarian attitudes gender roles individuals also found less likely engaged violent relationships lower rate stis including hiv unintended pregnancy ref name unfpaorg emphasizing rights gender issues programs help reduce gender based violence bullying promote safe schools empower young people advocate rights advance gender equality ref name unfpaorg sexual health interventions designed input adolescents adolescents suggested sex education positive less emphasis anatomy


scare tactics focus negotiation skills sexual relationships communication details sexual health clinics advertised areas adolescents frequent example school toilets shopping centres ref name dicenso ref also us review concludes overwhelming weight evidence shows sex education discusses contraception increase sexual activity ref name kirby isbn ref ref name kirby ref study found comprehensive program hastened initiation sex increased frequency sex results many people fear report showed comprehensive programs worked genders major ethnic


groups sexually inexperienced experienced teens different settings different communities ref name kirby united nations population fund unfpa recommends comprehensive sexuality education enables young people make informed decisions sexuality according unfpa ref name guide ref blockquote taught several years introducing age appropriate information consistent evolving capacities young people includes scientifically accurate curriculum based information human development anatomy pregnancy also includes information contraception sexually transmitted infections stis including hiv goes beyond information encourage confidence improved communication skills curricula also address


social issues surrounding sexuality reproduction including cultural norms family life interpersonal relationships blockquote places comprehensive sex education sti pregnancy rates drop ref name ref attitudes children also found differ depending content sex education one comparison results made sex education curriculum netherlands us average teens europe netherlands comprehensive sex ed sex younger age teens us less comprehensive sex ed however teens


integrated every aspect discussions includes human rights protection fulfilment empowerment impact gender discrimination importance equality gender sensitivity ideas underlying gender roles sexual abuse gender based violence harmful practices also discussed taken together information teaches young people life skills necessary assume responsibility behavior respect rights others ref name unfpaorg comprehensive sex education enables young people make informed decisions sexuality health programmes build life skills increase responsible behaviors


sex education necessary prepare young task ahead according officials generally agree kind planned sex education necessary sometimes formal sex education taught full course part curriculum junior high school high school times one unit within broad biology health home economics physical education class schools offer sex education since remains controversial issue several countries particularly united states especially regard age children start receiving


education amount detail revealed including lgbt sex education ref name nyt topics dealing human sexual behavior eg safe sex practices masturbation premarital sex sexual ethics wilhelm reich commented sex education time work deception focusing biology concealing excitement arousal pubescent individual mostly interested reich added emphasis obscures believed basic psychological principle worries difficulties originate unsatisfied sexual impulses leepson asserted majority people favor sort sex instruction public


schools become intensely controversial issue unlike subjects sex education concerned especially sensitive highly personal part human life suggested sex education taught classroom ref name delamare problem pregnancy adolescents delicate difficult assess using sex education calderone believed otherwise stating answer adolescents' sexual woes pregnancy lie primarily school programmes best remedial needed prevention education parents involved sex education


contentiously debated chief controversial points whether covering child sexuality valuable detrimental whether lgbt sex education integrated curriculum ref name nyt use birth control condoms hormonal contraception impact use pregnancy outside marriage teenage pregnancy transmission stis increasing support abstinence sex education conservative groups one primary causes controversy countries conservative attitudes towards sex education including uk us higher incidence stis teenage pregnancy ref name joy sex education http educationguardiancouk schools comment story html


joy sex education george monbiot ''the guardian'' may ref public opinion survey conducted britain canada united states angus reid public opinion november asked adult respondents look back time teenagers describe useful several sources enabling learn sex far largest proportion respondents three countries canada britain united states said conversations friends useful moderately useful next reputable source


media television books movies magazines mentioned three five british canadians half americans useful ''angus reid public opinion'' said half canadians americans found sex education courses school useful britons share view half americans say conversations family useful canadians britons said ref name opinion ref area africa sex education africa focused stemming growing aids epidemic governments


region established aids education programs partnership world health organization international ngos programs undercut significantly mexico city policy initiative put place president ronald reagan suspended president bill clinton instated president george w bush global gag rule required nongovernmental organizations agree condition receipt federal funds organizations would neither perform actively promote abortion method family planning nations policy suspended one first official acts united


states president barack obama incidences new hiv transmissions uganda decreased dramatically clinton supported comprehensive sex education approach including information contraception abortion ref name uganda https wwwwhoint inf new aids htm uganda reverses tide hiv aids ref according ugandan aids activists policy undermined community efforts reduce hiv prevalence hiv transmission ref name pepfar http wwwstdcheckcom aids reliefphp health gap pepfar policies retrieved february ref egypt teaches knowledge male female reproductive systems sexual organs contraception stds public schools second third years middle preparatory phase students aged coordinated program undp


unicef ministries health education promotes sexual education larger scale rural areas spreads awareness dangers female genital mutilation asia state sex education programs asia various stages development like country philippines topic sex education considered controversial deals different topics sometimes vague broad implemented largely society thailand thailand progress sex education boundaries pushed forward


revision curriculum first national policy sexuality education schools announced sex education taught schools called life family studies content consisted issues related reproductive system personal hygiene education curriculum revised several times involving efforts government non government sectors sex education accepted problem solving tool adolescent sexual reproduction health issues consequence educational reform following national education act increasing awareness


problems related adolescents' sexual practices emergence women 's sexuality queer movements another new approach sexuality education curricula thailand teenpath project developed path thailand path also succeeded institutionalizing sexuality education curricula schools since india india many programs promoting sex education including information aids sex sexuality schools well public education advertising aids clinics however universally available ref source untaboo company dedicated sex education however age appropriate programs sex sexuality safety awareness education


conducted schools small private groups outside schoolssexual reproduction different contraceptive methods taught grades age compulsorily china new five year project introduced china family planning association promote reproductive health education among chinese teenagers unmarried youth twelve urban districts three counties included discussion sex within human relationships well pregnancy hiv prevention ref name chinasexed http wwwchinadevelopmentbriefcom node sex education begins break taboos china development brief june ref since


education mandatory age mainly covering biological topics menstruation ejaculation ref name swedsexed sri lanka sex education traditionally consisted reading reproduction section biology textbooks young people taught years old international planned parenthood federation bbc world service ran part series known ''sexwise'' discussed sex education family life education contraception parenting first launched south asia extended worldwide ref name sexwise http wwwunescoorg courier uk apprend htm involve young interview dr pramilla senanayake assistant director general international planned parenthood federation ref


singapore singapore family planning association developed series sex education programs young people focusing strict control sexual behavior age singapore government attaches great importance moral education young people sentencing sexual offenses strict europe world health organization german federal office health education recommend sex education children ages finland finland sexual education usually incorporated various compulsory courses mainly part biology lessons lower grades later course related general health


issues france france sex education part school curricula since schools expected provide hours sex education pass condoms students grades aged january french government launched information campaign contraception tv radio spots distribution five million leaflets contraception high school students ref name britsexed http wwwunescoorg courier uk apprendhtm britain sex education fire ''unesco courier'' ref september government launched new program called 'the abcd equality' whose main aim fight


gender stereotypes school ultimate goal foster mutual respect boys girls early impacts conception world later germany first state sponsored courses sex education introduced breslau prussia c dr martin chotzen ref name hammill ref germany sex education part school curricula since since sex education governmental duty law normally covers subjects concerning process growing bodily changes puberty emotions involved biological process reproduction sexual activity partnership homosexuality unwanted pregnancies


complications abortion dangers sexual violence child abuse sex transmitted diseases comprehensive enough sometimes also includes things curricula sex positions schools offer courses correct usage contraception sex survey world health organization concerning habits european teenagers revealed german teenagers care contraception birth rate among year olds low per people compared births per people uk births per people bulgaria incidentally


highest birth rate europe ref name european sex survey ref german constitutional court later european court human rights rejected complaints several baptists germany concerning mandatory sex education poland time people 's republic poland since sex education one school subjects however relatively poor achieve actual success practically vanished school life currently subject called family life education rather sex education schools explicitly require parental consent children attend sex education classes


netherlands required law receive level sex education flexibility subject taught however required principles sexual diversity sexual assertiveness ref name ref moreover according amy schalet dutch parents tend form close relationships children openly discussing teen sexuality dutch parents try accept children 's romantic relationships even allow sleepovers expecting sex media encouraged open dialogue health care system guarantees confidentiality non judgmental approach netherlands one lowest teenage pregnancy rates


world dutch approach often seen model countries ref name dutchmodel http unesdocunescoorg images epdf dutch model ''unesco courier'' ref slovakia slovakia content sex education varies school school frequently segment larger lesson plan subject akin nature science english course covers biology petrology generally sex ed content taught slovakia quite basic sometimes lacking though exactly given lesson contains varies among schools dependent teacher 's knowledge subject uncommon teachers


rely students asking questions opposed documentaries discussions textbooks class debates classes usually divided boys girls boys taught basics sex usually limited dialogue student teacher annotated diagrams genitalia girls additionally taught menstruation pregnancy sweden sweden sex education established secondary education grades subject usually started kindergarten continues cumulatively throughout student 's entire schooling sexual education incorporated different subjects biology history ref name swedsexed https webarchiveorg web http wwwtimecom time magazine article html sex


many accents ''time'' ref swedish association sexuality education rfsu sex education emphasizes sexual diversity freedom enjoyment ref name ref rfsu collaborate frequently government organizations national institute public health alongside emphasis sexual diversity swedish sex education equal incorporations lesbian gay sexuality well heterosexual sexuality provide knowledge masturbation oral anal sex well heterosexual genital intercourse ref name switzerland switzerland content amount sex education decided cantonal level geneva courses given


secondary level first girls since compulsory programs implemented secondary level classes since french speaking cantons since generalized courses implemented states duly formed trained specialists working within school health services secondary level interventions primary schools started basic objective empowering children strengthening resources giving capacity discriminate right wrong based upon allowed law society also given knowledge


youth needs know sexual life conformity age maturity german part country situation somewhat different sex education school implemented program fairly recent subject responsibility given school teachers though federal structures give authority state decide efforts notably auspices swiss branch ippf international planned parenthood federation look propose possible models application take account factors sex education according different levels


currently withdraw children parts sex relationship education want compulsory curriculum focuses reproductive system foetal development physical emotional changes adolescence information contraception safe sex discretionary discussion relationships often neglected ref name britsexed britain one highest teenage pregnancy rates europe however halved across england wales recent years continue fall schools actively choose deliver age appropriate relationship sex education early years foundation stage include differences


boys girls naming body parts areas body private touched unless child happy gives consent following sustained political pressure march announced department education dofe september relationship education primary schools relationship sex education rse secondary schools made mandatory england uk government existing category sre sex relationship education referred rse relationship sex education british government consultation held


doug ford inviting parents file complaints teachers comply change mandatory sex education removed quebec provincial curriculum leaving discretion teacher rates syphilis gonorrhea rising province since change several researchers sex educators criticizing current policy notably lisa trimble stephanie mitelman brought back facultative subject mandatory school year united states almost us students receive form sex education least


grades many schools begin addressing topics grades however students learn varies widely curriculum decisions decentralized many states laws governing taught sex education classes contain provisions allow parents opt state laws leave curriculum decisions individual school districts ref name kaiser ref sex education required states also require hiv education states require hiv education states require information taught medically accurate law states allow parents


opt kids sex ed states require instruction sexual activity occur marriage states require abstinence stressed contextually states must inclusively discuss sexual orientation legally must emphasize heterosexuality provide negative information homosexuality states require importance consent sexual situation example study guttmacher institute found us sex education courses grades cover puberty hiv stis abstinence implications teenage pregnancy resist peer pressure studied topics


nearly births per ref name cdc ref percentage teens reporting ever sex currently sexually active showed small declines still us highest teen birth rate one highest rates stis among teens industrialized world ref name advocates youth public opinion polls conducted years found vast majority americans favor broader sex education programs teach abstinence although abstinence educators recently published poll data opposite conclusion proponents comprehensive


sex education include american psychological association american medical association national association school psychologists american academy pediatrics american public health association society adolescent medicine ref name adolescent health american college health association ref name adolescent health http wwwadolescenthealthorg positionpaper abstinence edu policies programspdf adolescent health ref argue sexual behavior puberty given therefore crucial provide information risks minimized also claim denying teens factual information leads unwanted pregnancies stis hand proponents abstinence sex education object curricula


fail teach standard moral behavior maintain morality based sex within bounds marriage healthy constructive value free knowledge body may lead immoral unhealthy harmful practices within last decade federal government encouraged abstinence education steering billion dollars programs states decline funding continue teach comprehensive sex education funding one federal government 's two main abstinence funding programs ''title v'' extended december


congress debating whether continue past date impact rise abstinence education remains question date published studies abstinence programs found consistent significant program effects delaying onset intercourse ref name advocates youth ref study ordered us congress found middle school students took part abstinence sex education programs likely sex use contraception teenage years abstinence advocates claimed study flawed


narrow began abstinence curricula infancy studies demonstrated positive effects according anna mulrine ''us news world report'' records show professionals still know method sex education works best keep teens engaging sexual activity still working find virginia virginia uses sex education program called national campaign prevent teen unplanned pregnancy national campaign created focuses preventing teen unplanned pregnancies young adults national campaign set goal


reduce teen pregnancy rate ten years virginia department health ranked virginia th teen pregnancy birth rates virginia also rated teen births per girls aged healthy people goal teen pregnancy rate pregnancies per females age texas sex education texas recently become policy much focus state rise recent protests proposed bills texas house current policy focus much scrutiny


senate bill enacted texas left decision inclusion sex education classes within schools individual districts school board members entitled approve curricula taught however bill certain criteria school must abide choosing teach sex ed include present abstinence sexual activity preferred choice behavior relationship sexual activity unmarried persons school age devote attention abstinence sexual activity behavior emphasize abstinence sexual


activity used consistently correctly method percent effective preventing pregnancy sexually transmitted diseases infection human immunodeficiency virus hiv acquired immune deficiency syndrome aids emotional trauma associated adolescent sexual activity direct adolescents standard behavior abstinence sexual activity marriage effective way prevent pregnancy sexually transmitted diseases infection hiv aids teach contraception condom use terms real world failure rates statistics based laboratory rates instruction contraception condoms included


factual errors distort truth condoms stds according texas state representative mike villarreal responsibility ensure children receive accurate information classroom particularly students' health stake villarreal said 're dealing myriad problems texas result sky high teen pregnancy rates cannot allow schools provide erroneous information stakes far high mind many state legislators proposed bills improve sex education texas schools sb hb feb senator ellis


proposed education works bill bill would require schools teach sex education provide evidence based age appropriate information emphasizes importance abstinence effective method avoiding sexually transmitted infections stis pregnancy also teaching contraceptive methods avoid stis pregnancy hb sb representatives joaquin castro mike villarreal introduced bill calling abstinence plus sexual health education bill bill would medically accurate information including abstinence contraception really takes parent bill received hearing left