special emotional needs ''f rderschule f r blinde'' school blind blind children ''f rderschule f r sehbehinderte'' school visually impaired children visually challenged ''f rderschule f r geh rlose'' school deaf deaf children ''f rderschule f r schwerh rige'' school hearing impaired children hearing impaired ''f rderschule f r k rperbehinderte'' school children physical disabilities children physical disabilities ''f rderschule f r sprachbehinderte'' school children language disorders children language disorders ''f rderschule f r taubblinde'' school deafblind children deafblind ''schule f r kranke'' school ill children


children ill attend school hospitalized longer period time ''f rderschule f r schwer mehrfach behinderte'' school children severe multiple disabilities children severe multiple disabilities need special care attention sometimes children susceptible basic emotional sensory stimulation thus teachers school well schools deafblind highly specialized professionals one german students attends special school teachers schools specially trained professionals specialized special needs education

Applied science
Education
Curriculum and instruction
Special education


disabilities received significant bonus eight points university entrance examination criticized unfair ref name ofqual republic ireland national council special education ncse supports students physical intellectual disabilities netherlands general rule students special educational needs integrated regular mainstream schools appropriate support going school together policy ''weer samen naar school'' ref name ofqual four types disability specific special schools exist national policy moving towards suitable education ''passend onderwijs'' based individual 's strengths weaknesses ref name ofqual strong emphasis


placed specific needs positive capabilities individual rather limitations ref name ofqual disabilities normally documented experts ref name ofqual norway national support system special needs education statped managed norwegian directorate education training general objective statped give guidance support charge education municipalities county administrations ensure children young people adults major special educational needs secured well advised educational developmental provisions institutions affiliated statped offer broad spectrum


resources students special educational needs make progress participate school ref name ofqual local school unable provide appropriately individual student student may transferred special school ref name ofqual spanish non governmental organizations like traditionally provided significant services students disabilities ref name ofqual sweden local schools significant autonomy based national guidelines schools expected help students meet goals set ref name ofqual special schools students low abilities attend normal education


media criticism fact students light problems dyslexia placed special schools seriously hampering chances labour market switzerland education controlled cantons special education programs vary place place ref name ofqual however integration typical ref name ofqual students assessed according individual learning goals ref name ofqual united kingdom england wales acronym ''sen'' special educational needs denotes condition special educational needs services provide support programmes


instead individual plan group plans used group students similar goals scotland additional support needs act places obligation education authorities meet needs students consultation agencies parents scotland term special educational needs sen variants official terminology although recent implementation additional support learning act means ''sen'' ''asn'' additional support needs used interchangeably current common practice turkey young age students special needs


turkey provided special education ministry education responsible giving education need ref name ref order get special education required certain things residency certificate nbsp written application parents school administration nbsp personal development report child already registered nbsp child 's health report hospital ref name special needs students receive individualized education program bep outlines school meet student 's individual needs zel e itim kurumlar netmeli eky requires students special needs provided free appropriate


public education least restrictive environment appropriate student 's needs government run schools provide special education varying degrees least restrictive settings full inclusion restrictive settings segregation special school education offered school must appropriate student 's individual needs schools required maximize student 's potential provide best possible services unlike developed world american schools also required provide many medical services speech therapy student needs services according


department education approximately percent school aged children currently receive type special education services countries world students poor ethnic minorities speak dominant language fluently disproportionately identified needing special education services poor people refugees likely limited resources employ inexperienced teachers cope well student behavior problems thereby increasing number students referred special education teacher efficacy tolerance gender years experience special education referrals latin america


little action taken educate children disabilities colombia children would left home without much interaction outside world special education researched across country education programs created people disabilities given access public school classes increase advocation accessibility children disabilities initiated awareness recognition rights group children education improvement recent years still slow development special education programs special education policy


colombia statistics dane departamento administrativo nacional de estad stica state disabled people reside colombia representing country 's population according research disabled students colombia attend mainstream school able attend school ref name correa montoya lucas castro mart nez marta catalina disability social inclusion colombia saldarria ga concha foundation alternative report committee rights persons disabilities saldarriaga concha foun dation press bogot dc colombia p ref history special education colombia


public schools include students disabilities called law colombia entered convention rights persons disabilities agreement among united nations education scientific culture organization unesco protect people live disabilities ref name recent development special education colombia article law passed law states ministry education define policy regulate scheme education persons special educational needs promoting educational access quality system based inclusion educational services


colombian government also made financial strides special education investing million ref name north america north america special education commonly abbreviated ' 'special ed'' ''speced'' ''sped'' ''sped'' professional context canada education canada responsibility individual provinces territories ref name ofqual rules vary somewhat place place however inclusion dominant model major exams canadian schools commonly use accommodations specially printed examinations students visual impairments assessing achievements students special needs ref name ofqual


instances alternative assessments modifications simplify tests permitted students disabilities may exempted tests entirely ref name ofqual united states special needs students receive individualized education program iep outlines school meet student 's individual needs individuals disabilities education act idea requires students special needs provided free appropriate public education least restrictive environment appropriate student 's needs government run schools provide special education varying degrees least restrictive settings full inclusion restrictive settings


receiving special education services home hospital ref name teachers schools society education offered school must appropriate student 's individual needs schools required maximize student 's potential provide best possible services unlike developed world american schools also required provide many medical services speech therapy student needs services according department education approximately million children roughly percent school aged children currently receive type special education services countries


world students poor ethnic minorities speak dominant language fluently disproportionately identified needing special education services ref name blanchett poor black latino urban schools likely limited resources employ inexperienced teachers cope well student behavior problems thereby increasing number students referred special education part due civil rights movement researchers began study disparity education amongst people disabilities landmark ''brown v board education'' decision declared unconstitutional


separate equal arrangements public schools students different races paved way ''parc v commonwealth pennsylvania'' ''mills vs board education district columbia'' challenged segregation students special needs courts ruled unnecessary inappropriate segregation students disabilities unconstitutional ref name blanchett ref congress responded court rulings federal education handicapped children act since renamed individuals disabilities education act idea law required schools provide services students previously denied access appropriate education us government run


schools dominant model inclusion united states three five students academic learning challenges spend overwhelming majority time regular classroom integrating technology special education classrooms autism autism autism spectrum disorder asd refers range conditions conditions involve challenges social skills repetitive behaviors speech nonverbal communication also involve unique strengths differences autism disability impairs social interactions communication skills person people autistic tend think act differently others


many children autism spectrum disorder asd find comfortable device hands nbsp students autism apps called visual scene displays helpful children difficulty verbal skills according jules csillag speech language pathologist focuses special ed tech apps scenespeak speech milo help autistic children develop storytelling skills text speech voice interactive storybooks using apps like classroom improve autistic student 's verbal skills several controversies surrounding diagnoses causes autism believed


single cause autism research seems suggest autism normally result genetic environmental influences syndrome student syndrome assistive technology help learning experience author nbsp ''down syndrome promising future together'' nbsp terry hassold got phd human genetics explains students syndrome delays cognitive ability brains late reaction neurological system sends message task late reaction tend take longer complete task


average student assistive technology crucial helping 's students writing ability syndrome children tend shorter fingers lowered thumb making ability write difficult also usual wrist bones formed making difficult hold objects slanted desks one type assisted technology aid successful ability write three ring binder used create slanted desk turning binder sideways also students syndrome often try hold pencils anchoring thumb rather


using tip thumb shortened pencils triangular shaped pencils encourage students hold correctly using assistive technologies help syndrome students educational process special education sports benefits many people special needs denied want participate sport us office civil rights ensures students disabilities always opportunities participate extracurricular athletics equal students special education students benefit sports many ways example studies show boosts self confidence


improves participant 's skills relationship building working part team types sports sport altered special education purposes ref name ref popular sports swimming wheel chair soccer handball gymnastics weightlifting ref name organizations programs many competitive organizations available special needs student athletes example special olympics annual world wide competition held children disabilities want participate sports organizations include paralympic games unified sports latter pairs participants without


intellectual disabilities team educational institutions also promote adapted physical education tailors sports students certain disabilities organizations like stride adaptive sports help educational institutions providing opportunities special education student athletes sports might include wheelchair basketball sledge hockey sports even organizations example baseball athletes participate miracle league little league challenger division another organization soccer athletes participate us youth soccer topsoccer kicks sports played adapted include track field


quad rugby tennis bowling skiing impact study examined impact sharp reduction provision special education services texas found policy change substantially reduced high school completion rates college enrollment rates students denied access special education see also adapted physical education disability poverty disability studies disadvantaged early childhood intervention inclusive learning environment learning space mainstreaming education matching person technology model post secondary transition high school students disabilities reasonable accommodation response intervention special assistance program australian education special


needs supported employment services tracking education vocational rehabilitation washington county closed circuit educational television project references sources reading birsh judith r wolf b eds multisensory teaching basic language skills third edition baltimore brookes wilmshurst l brue w complete guide special education nd ed san francisco jossey bass snell e brown f ''instruction students severe disabilities'' th edition seoul pearson external links http wwweuropean agencyorg european agency special needs inclusive education http wwwparentcenterhuborg center parent information resources us http wwwcecspedorg council exceptional children us


http wwwedgov offices list osers indexhtml office special education rehabilitative services us department education https webarchiveorg web http onlinesjuedu sites sju files edu terms acronymspdf guide special education terms acronyms us alternative education educational programs segregation


''see islamic schools branches different schools thought see aqidah concept different creeds islam see kalam concept theological discourse'' '''schools islamic theology''' various islamic schools branches different schools thought regarding ''aqidah'' creed according muhammad abu zahra qadariyah jahmis murji'ah mu tazila batiniyya ash ar tur har ancient schools islamic theology meeting theologians abd allah musawwir mid th century main schism sunn shi kharijite branches islam initially political theological time


theological differences developed throughout history islam ref name izutsu ref divinity schools islam according ''encyclopaedia qur n'' qur n displays wide range theological topics related religious thought late antiquity prophet mu ammad presents coherent vision creator cosmos man main issues muslim theological dispute prove hidden wording qur nic message closely tied mu ammad 's biography ref name eoq quran ref however historians scholars islamic studies recognize istances theological thought already


developed among polytheistic pagans pre islamic arabia belief fatalism '' adar'' reoccurs islamic theology regarding metaphysical debates attributes god islam predestination human free ref name schmidtke br ref original schism kharijites sunn shi among muslims disputed political religious succession guidance muslim community ''ummah'' death islamic prophet muhammad ref name izutsu essentially political position kharijites developed extreme doctrines set apart mainstream sunn shi muslims ref name izutsu shi believe


ali ibn abi talib true successor muhammad sunn consider abu bakr hold position kharijites broke away shi sunn first fitna first islamic civil war ref name izutsu particularly noted adopting radical approach ''takf r'' excommunication whereby declared sunn shi muslims either infidels ''kuff r'' false muslims ''mun fi n'' therefore deemed worthy death perceived apostasy ''ridda'' ref name izutsu ''aqidah'' islamic term meaning creed belief ref name abdel haleem ref religious belief system


creed considered example ''aqidah'' however term taken significant technical usage muslim history theology denoting matters muslims hold conviction term usually translated theology traditions divisions orthogonal sectarian divisions within islam mu tazilite may example belong ja fari zaydi even hanafi schools islamic jurisprudence one earliest systematic schools islamic theology develop mid th century mu tazila ref name schmidtke ref name peters ref mu tazilites emphasized reason rational thought positing injunctions god accessible


rational thought inquiry affirmed quran albeit word god created rather co eternal god would develop one contentious questions islamic theology ref name schmidtke ref name peters th century ash ar school developed response mu tazila ash ar tes still taught use reason understanding quran denied possibility deduce moral truths reasoning position opposed tur school taught certain moral truths may found use reason without aid


revelation another point contention relative position ''im n'' faith contrasted ''taqw '' piety schools islamic theology summarized '' ilm al kal m'' science discourse opposed mystical schools deny theological truth may discovered means discourse reason ilm al kal '' ilm al kal m'' literally science discourse ref name abdel haleem usually foreshortened '''kalam''' sometimes called islamic scholastic theology speculative theology rational undertaking born need establish defend tenets islamic faith doubters detractors 'ilm al kalam


incorporates aristotelian reasoning logic islamic theology ref name peters scholar kalam referred ''mutakallim'' plural ''mutakallim n'' distinguished philosophers jurists scientists many possible interpretations discipline originally called kalam one widest controversy discipline whether word god revealed quran considered part god 's essence therefore created whether made words normal sense speech therefore created ref name peters mu tazila first


group pursue undertaking mu tazila school asserted truth could known reason alone mu tazilite theology originated th century basra wasil ibn 'ata' stormed lesson hasan al basri following theological dispute mu tazilites asserted everything revelation could found rational means alone mu tazilites heavily influenced greek philosophy encountered began adopt ideas plotinus whose neoplatonic theology caused enormous backlash mu tazila longer considered orthodox school theology sunni muslims


bishriyya bishriyya followed teachings bishr ibn al mu'tamir distinct wasil ibn ata b hashim iyyah b h sham iyyah school mu'tazili thought rivaling school qadi abd al jabbar based primarily earlier teaching abu hashim al jubba'i son abu 'ali muhammad al jubba'i sunn schools theology sunnis adopted ash ariyya school theology similar r iyyah school also sunni adherents ref name heer lecture ref sunni muslims largest denomination islam known ''ahl sunnah wa l jam h'' simply ''ahl


sunnah'' word ''sunni'' comes word ' 'sunnah'' means teachings actions examples islamic prophet muhammad therefore term sunni refers follow maintain ' 'sunnah'' prophet muhammad sunnis believe muhammad appoint successor lead muslim ''ummah'' community death initial period confusion group prominent companions gathered elected abu bakr muhammad 's close friend father law first ''caliph'' islam sunni muslims regard first four caliphs abu bakr `umar ibn


al khatt b uthman ibn affan ali ibn abu talib al khulaf ur r shid n rightly guided caliphs rashidun position turned hereditary right caliph 's role limited political symbol muslim strength unity athari atharism ''textualism'' movement islamic scholars reject rationalistic islamic theology ''kalam'' favor strict textualism interpreting quran ref name halverson q ref name derived arabic word '''''' literally meaning remnant also referring narrative disciples called ''athariyya'' atharis followers


ref essence meaning accepted without asking bi la kaifa hand famous hanbali scholar ibn al jawzi states ''kitab akhbar sifat'' ahmad ibn hanbal would opposed anthropomorphic interpretations quranic texts al qadi abu ya'la ibn hamid ibn az zaghuni based abu'l faraj ibn al jawzi 's criticism ''athari hanbalis'' muhammad abu zahra professor islamic law cairo university deduced ''salafi aqidah'' located somewhere ta'tili anthropopathy '' absolute hir sm understanding tashbih qur'an '' ref name zahra muhammad abu zahra ''the history


madh'habs divinity schools islam'' ref ref name news http wwwarabnewscom node scholar renown muhammad abu zahrah ed adil salahi arab news published wednesday november accessed sunday june ref islam ''absolute hir sm'' total rejection ''ta'wil'' amongst fundamental characteristics '' new '' islamic school theology ash ar yyah mu tazila school theology challenged abu al hasan al ash ar famously defected formed rival ash ar school ash ar school took opposite position mu tazila insisted truth cannot known reason alone ash ar school claimed


truth known revelation without revelation unaided human mind would n't able know something good evil called attempt create middle position rationalism mu tazilites scripturalism traditionalists ref name heer lecture ref attempt explain god power control everything humans responsible sins al ash ar developed doctrine ''kasb'' acquisition whereby human acts even raising finger ''created'' god human performs


act ' 'responsible'' acquired act ref name glasse cyril glass huston smith ''the new encyclopedia islam'' rowman altamira page ref today ash ar school considered one orthodox schools sunni theology sunnis adopted ash'ari school basis shafi'i school jurisprudence supplied famous disciples ref name arabnewscom ref famous abul hassan al bahili abu bakr al baqillani al juwayni al razi al ghazali thus ash ar school became together maturidi main schools reflecting beliefs


sunnah ref name arabnewscom r iyyah maturidi school founded abu mansur al maturidi popular theological school amongst muslims especially areas formerly controlled ottomans mughals today maturidi school position favored ''ahl ar ra'y'' people reason includes hanafi school fiqh make majority sunni muslims maturidi school takes middle position ash'ari mu'tazili schools questions knowing truth free maturidis say unaided human mind


able find major sins alcohol murder evil without help revelation still maintain revelation ultimate source knowledge additionally maturidi believe god created control creation allows humans make individual decisions choices jahmiyyah jahmis followers islamic theologian jahm bin safwan associate al harith ibn surayj exponent extreme determinism according man acts metaphorically


way sun acts something sets ref name pest ref position adopted ash'ari school holds god 's omnipotence absolute perfect creation qadariyyah qadariyyah originally derogatory term designating early islamic theologians asserted human beings ontologically free perfect free whose exercise justifies divine punishment absolving god responsibility evil world ref name qadariyyah ref doctrines adopted mu'tazilis rejected ash'aris ref name qadariyyah tension free god 's omnipotence later


p ref kharijites reject doctrine infallibility leader muslim community contrast shi'a agreement sunnis modern day islamic scholar abul ala maududi wrote analysis kharijite beliefs marking number differences kharijism sunni islam kharijites believed act sinning analogous kufr disbelief every grave sinner regarded k fir disbeliever unless repents argument denounced mentioned bah even cursed used abusive language ordinary muslims also declared disbelievers first


ibadiyya ibadiyya common beliefs overlapping ashari mu'tazila sunni shi'ites ref name ess murji'ah murji'ah early islamic school whose followers known english murjites murji'ites murji'ah emerged theological school response kharijites early question relationship sin apostasy '' rida '' murji'ah believed sin affect person 's beliefs ''iman'' rather piety ''taqwa'' therefore advocated idea delayed judgement ''irjaa '' murji'ah maintain anyone proclaims bare minimum


faith must considered muslim sin alone cannot cause someone become disbeliever '' kafir '' murjite opinion would eventually dominate kharijites become mainstream opinion sunni islam later schools sunni theology adopted stance form developed theological schools concepts shi schools theology zaydi fivers ''zaydi school divinity'' close mu tazila school issues schools notably zaydi doctrine imamate rejected mu tazilites amongst shi zaydis


similar sunn since zaydism shares similar doctrines jurisprudential opinions sunn scholars b en iyyah ''the b en iyyah aq dah'' originally introduced ''abu l kh tt b muhammad ibn abu zaynab al asad '' ref name abu l b asad ref ref name biya ref later developed ''maym n al qadd h'' ref name z z mustafa ''mezhepler tarihi terimleri zl history madh'habs terminology dictionary '' ensar yay nc l k stanbul name trainer muhammad bin ism l agh r ibn j far established principles b en iyyah madh'hab later ref son '' abd h ibn maym n'' ref name maym n ref esoteric interpretation ref name b en ya ref qur'an members


''batiniyyah'' may belong either ismailis twelvers imami ism ' l ''ism ' l im mate'' differ twelvers ''living imams da'is'' centuries followed isma'il ibn jafar elder brother musa al kadhim rightful imam father ja'far al sadiq ismailis believe whether imam ismail die imam ja'far passed mantle im mate son mu ammad ibn ism ' l al maktum next imam batini twelver aq dah schools followers '' batiniyyah twelver madh'hab'' consist alevis nusayris developed


fiqh system pursue ja'fari jurisprudence combined population nearly around world overall muslim population ref name alevi ref alevism alevis sometimes categorized part twelver shia islam sometimes religious tradition markedly different philosophy customs rituals many ''tasawwuf '' characteristics express belief qur'an twelve imams reject polygamy accept religious traditions predating islam like turkish shamanism significant east central turkey sometimes considered sufi sect untraditional form religious leadership


scholarship oriented like sunni shia groups seven eleven million alevi people including denominations twelver shi'ites live anatolia ref name alevi alevi islamic school divinity turkey shia muslim people belong ja'fari jurisprudence madhhab tracks back sixth shia imam ja'far al sadiq '' also known imam jafar sadiq '' called ja'faris belong twelver shia although alevi turks considered part twelver shia islam belief different ja'fari jurisprudence conviction '' alevi turks '' unique


perplex conviction tracing back kaysanites shia khurramites considered ghulat shia according turkish scholar abd lbaki g lpinarli qizilbash '' red heads '' th century religious political movement azerbaijan helped establish safavid dynasty spiritual descendants khurramites among members ''qizilbash tariqah '' considered sub sect alevis two figures firstly ''abu muslim khorasani'' assisted abbasid caliphate beat umayyad caliphate later eliminated murdered caliph al mansur secondly ''babak khorramdin'' incited rebellion abbasid caliphate


consequently killed caliph al mu'tasim highly respected belief provides strong clues kaysanites shia khurramites origins addition safaviyya tariqah leader ''ismail i'' highly regarded individual belief alevi qizilbash tariqah associating ''imamah shia twelver doctrine '' conviction twelver shi'a islam aqidah '' theological conviction '' based upon syncretic fiqh system called batiniyya sufism ref name b en ya incorporates ''qarmatian sentiments'' originally introduced '' abu l kh tt b muhammad ibn abu zaynab al asad '' ref name abu l b asad ref name biya later developed '' maymun al q dd h '' son '' abd h ibn maymun '' ref name maym n


looks like sub classes twelver conviction includes batiniyya hurufism sevener qarmatians ismailism sentiments ref name b en ya may considered special groups following ja'fari jurisprudence like alawites class ghulat twelver shia islam special batiniyya belief somewhat similar isma'ilism conviction twelver branch shia islam muslim population turkey composed mu'tazila aqidah ja'fari jurisprudence madhhab batiniyya sufism aqidah maym n al q dd h fiqh alev cill aqidah maym n ibn abu l q sim sulaiman ibn ahmad ibn tabar n fiqh alawites ref name meym n altogether constitutes nearly one third


external pretense real pilgrimage internal one 's heart '' non attendance mosques ref name angelfire ref members sub groups claim god takes abode bodies human beings '' ul l'' believe metempsychosis ''tan sukh'' consider islamic law obligatory ''ib a'' similar antinomianism alevis criticizes course islam practiced overwhelmingly sunni shia population believe major additions implemented time ummayads easily refuse basic principles grounds believe contradicts


period prophet muhammad furthermore period ottoman empire alevis forbidden proselytise alevism regenerated internally paternal descent prevent penetration hostile outsiders alevis insisted strict endogamy eventually made quasi ethnic group alevi taboos limited interaction dominant sunni political religious centre excommunication ultimate punishment threatening married outsiders cooperated outsiders economically ate outsiders also forbidden use state sunni courts ref name angelfire bakt shism '' bekta ilik '' founder bektashiyyah sufi order hac bekta veli '' jj


called '' bel evladlar children loins '' became hereditary spiritual leaders rural alevis ''baba an'' faithful path '' yol evladlar children way '' dominated official bektashi sufi order elected leadership ref name angelfire bektashism places much emphasis concept wahdat ul wujood unity formulated ibn arabi often labeled pantheism although concept closer panentheism bektashism also heavily permeated shiite concepts marked veneration ali twelve imams ritual


prophetic practice sunnah written doctrine specific thus rules rituals may differ depending whose influence one taught bektashis generally revere sufi mystics outside order ibn arabi al ghazali jelalludin rumi close spirit bakt shi aq dah four spiritual stations bektashiyyah ''' sharia tariqa haqiqa fourth station marifa considered unseen actually ''the center'' ''haqiqa'' region marifa essence four stations bektashi order sufi order shares much


common islamic mystical movements need experienced spiritual guide called ''baba'' bektashi parlance well doctrine four gates must traversed sharia '' religious law '' tariqah '' spiritual path '' haqiqah '' truth '' marifa '' true knowledge '' bektashis hold qur'an two levels meaning outer ''z her'' inner ''b en'' ref name b en ref hold latter superior eternal reflected understanding universe humanity view also


found ismailism batiniyya ref name b en ya bektashism also initiatic members must traverse various levels ranks progress along spiritual path reality first level members called ''a ks'' taken initiation order nevertheless drawn following initiation called ''nasip'' one becomes ''m hip'' time ''m hip'' one take vows become ' 'dervish'' next level dervish ''baba'' ''baba'' lit father considered head ''tekke'' qualified


islamic view last judgment shia ''hadiths'' include sayings imams many muslims criticise shia certain beliefs practices including practices mourning muharram ''m tam'' largest shia school thought predominant azerbaijan iran iraq lebanon bahrain significant population pakistan india afghanistan kuwait eastern province saudi arabia twelver shia followers ''either jaf'ari batiniyyah madh'habs'' imami ja'faris followers ''the jaf'ari madh'hab'' divided following sub divisions followers


''the theology twelvers '' usulism usuli form overwhelming majority within twelver shia denomination follow marja taqlid subject taqlid fiqh concentrated iran pakistan azerbaijan india iraq lebanon imam ali shrine najaf iraq shias believe ali buried akhbarism akhbari similar usulis however reject ijtihad favor hadith concentrated bahrain shaykhism shaykhism islamic religious movement founded shaykh ahmad early th century qajar dynasty iran retaining minority following iran


tariqat'' pp beirut ref one million three hundred fifty thousand lived syria lebanon estimated population syria million alawite islamic school divinity alawites consider muslims although sunnis dispute ref name globsec http wwwglobalsecurityorg military intro islam alawihtm alawi islam globalsecurityorg ref alawite doctrine incorporates gnostic neo platonic islamic christian elements therefore described syncretistic ref name friedman ref theology based divine triad ref name globsec ref name princeton ref ref name friedman ref trinity core


alawite belief ref name plain ref triad comprises three emanations one god supreme aspect entity called essence ref name plain meaning ref name friedman translations ''ma'na'' together two lesser emanations known name ''ism'' veil ''hijab'' gate ''bab'' ref name princeton ref name friedman ref name plain ref name peters ref emanations manifested different human forms several cycles history last cycle ali essence meaning muhammad name salman persian gate ref name princeton ref name plain ref name peters alawite belief


summarised formula turn gate bow name adore meaning ref name globsec claim alawites believe ali deity contested scholars misrepresentation basis ali fact considered essence form human believers grasp god alawites also hold originally stars divine lights cast heaven disobedience must undergo repeated reincarnation metempsychosis ref name plain returning heaven ref name globsec ref name peters reincarnated


christians others sin animals become infidels ref name globsec ref name cs http countrystudiesus syria htm alawis countrystudiesus us library congress ref alawite beliefs never confirmed modern religious authorities ref name yunis p 'abd al latif al yunis mudhakkirat al duktur 'abd al latif al yunis damascus dar al `ilm p ref alawites tend conceal beliefs ''taqiyya'' due historical persecution ref name telegraph https wwwtelegraphcouk news religion secretive sect rulers syriahtml secretive sect rulers syria telegraph aug ref tenets faith secret known select ref name globsec ref therefore described mystical sect ref name booksgooglecouk ref addition islamic


festivals alawites reported celebrate honor certain christian festivals birth jesus palm sunday ref name kaplan ref ref name glasse ref important feast eid al ghadeer alawite aq dah alawites always described twelver shi'ite muslims recognized prominent lebanese shi'ite cleric musa al sadr ref name kramer ref sunni grand mufti jerusalem haj amin al husseini issued ''fatwa'' recognising part muslim community interest arab nationalism ref name bar asherkootstra ref however athari sunni modern day salafis scholars ibn kathir '' disciple ibn


taymiyya '' categorised alawites pagans writings ref name globsec ref name abdullah abd allah umar f ''islamic struggle syria'' berkeley mizan press c pp ref barry rubin suggested syrian leader hafiz al assad son successor bashar al assad pressed fellow alawites behave like ' 'regular muslims'' shedding least concealing distinctive aspects early booklet ''al `alawiyyun shi'atu ahl al bait'' alawites followers household prophet published signed numerous 'alawi' men religion described doctrines imami shia alawite additionally


recent movement unite alawism branches twelver islam educational exchange programs syria qom ref name cofr ref sources discussed sunnification alawites al assad regime ref name dilemma joshua landis director center middle east studies writes hafiz al assad tried turn alawites 'good' read sunnified muslims exchange preserving modicum secularism tolerance society hand al assad declared alawites nothing twelver shiites ref name dilemma http faculty staffouedu l joshuamlandis syriablog asads alawi dilemmahtm syrian comment asad 's alawi dilemma october ref paper islamic education


syria landis wrote mention made syrian textbooks controlled al assad regime alawites druze ismailis shia islam islam presented monolithic religion ali sulayman al ahmad chief judge baathist syrian state said k z lba l k qizilbash aq dah shah ismail sheikh safavi tariqa founder safavid dynasty iran commander chief k z lba armies contributed lot development implementation ''the qizilbash aq dah'' amongst turkmen people qizilbash bektashi tariqah shared common religious beliefs


practices becoming intermingled alevis spite many local variations isolated sunni ottomans twelver shi`a safavids qizilbash bektashi developed traditions practices doctrines early th century marked closed autonomous religious community result immense pressures conform sunni islam members alevism developed tradition opposition '' ib '' forms external religion ref name angelfire doctrine qizilbashism well explained following poem written shaykh safaviyya tariqah sh h ism il khatai lines poetry may


easily judged act shirk '' polytheism '' sunni ulama b en ref name b en ta w l '' inner explanation '' qizilbashism tashbih karram iyyah ''anthropomorphic anthropopathic karram iyyah'' founded ab abd h mu ammad b karr ibn karram considered god substance body ''jism'' finite certain directions comes contact throne ref name ess ref ref name mat ref anthropopathy history ghul shia belief incarnation first emerged saba iyya later personalities like muhammad ibn al hanafiyyah abu muslim sunpadh


ishaq al turk al muqanna babak khorramdin maziar ismail become subject god incarnates ahmadiyya ahmadis' beliefs aligned sunni tradition five pillars islam six articles islamic faith likewise ahmadis accept qur'an holy text face kaaba prayer accept authority hadiths reported sayings stories muhammad practice sunnah traditions muhammad however many muslims consider ahmadis heretics ahmadi teachings state founders major world religions divine origins god


working towards establishment islam final religion complete included previous teachings religion believe religions gone astray present form completion consummation development religion came coming muhammad perfection manifestation muhammad 's prophethood conveyance message destined occur coming mahdi ahmadiyya muslim community regard mirza ghulam ahmad claimed promised messiah second coming


christ mahdi awaited muslims 'subordinate' prophet muhammad whose job restore sharia given muhammad guiding rallying disenchanted ummah back islam thwart attacks islam opponents promised one religions fulfilling eschatological prophecies found scriptures abrahamic religions well zoroastrianism indian religions native american traditions others ref name ita invitation ahmadiyyat mirza bashir ud din mahmood ahmad part ii argument chapter promised messiah promised one religions ref ahmadi muslims believe ahmad divinely commissioned


true reflection muhammad 's prophethood establish unity god remind mankind duties towards god god 's creation see also outline islam glossary islam abdol hamid khosro shahi index islam related articles islamic eschatology islamic schools branches islamic studies list extinct shia sects shia sunni relations shi'ite crescent succession muhammad sunni islam references external links http islamqainfo en online fatwa site islam question answer http wwwmasudcouk islam ahm newmadhhhtm four sunni schools thought http wwwaskimamorg ask imam islam q http wwwsunnipathcom online islamic learning https webarchiveorg web http wwwtasawwuforg sufism


'''psychophysics''' quantitatively investigates relationship physical stimuli sensations perceptions produce psychophysics described scientific study relation stimulus sensation ref name gescheiderpix ref completely analysis perceptual processes studying effect subject 's experience behaviour systematically varying properties stimulus along one physical dimensions ref name bruce ref ''psychophysics'' also refers general class methods applied study perceptual system modern applications rely heavily threshold measurement ref name boff kaufman thomas ref ideal observer analysis signal detection theory ref


name gescheiderchap ref psychophysics widespread important practical applications example study digital signal processing psychophysics informed development models methods lossy compression models explain humans perceive little loss signal quality audio video signals formatted using lossy compression history many classical techniques theories psychophysics formulated gustav theodor fechner leipzig published ''elemente der psychophysik elements psychophysics '' ref name fechner ref coined term psychophysics describing research intended relate physical stimuli contents consciousness sensations '' empfindungen ''


physicist philosopher fechner aimed developing method relates matter mind connecting publicly observable world person 's privately experienced impression ideas inspired experimental results sense touch light obtained early german physiologist ernst heinrich weber leipzig ref name snodgrass snodgrass jg psychophysics ''experimental sensory psychology'' b scharf ed pp ref ref name gescheiderchap ref notably minimum discernible difference intensity stimuli moderate strength noticeable difference jnd weber shown


constant fraction reference intensity fechner referred weber 's law fechner derived well known logarithmic scale known fechner scale weber 's fechner 's work formed one bases psychology science wilhelm wundt founding first laboratory psychological research leipzig institut f r experimentelle psychologie fechner 's work systematised introspectionist approach psychology science consciousness contend behaviorist approach even verbal responses physical stimuli psychological research nazi germany essentially came


halt approaches eventually began replaced use stimulus response relationships evidence conscious unconscious processing mind fechner 's work studied extended charles peirce aided student joseph jastrow soon became distinguished experimental psychologist right peirce jastrow largely confirmed fechner 's empirical findings particular classic experiment peirce jastrow rejected fechner 's estimation threshold perception weights far high experiment peirce jastrow fact invented randomized experiments


randomly assigned volunteers blinded repeated measures design evaluate ability discriminate weights ref name smalldiff ref ref name telepathy ref ref name stigler ref ref name dehue ref peirce 's experiment inspired researchers psychology education developed research tradition randomized experiments laboratories specialized textbooks ref name smalldiff ref name telepathy ref name stigler ref name dehue peirce jastrow experiments conducted part peirce 's application pragmaticism program human perception studies considered perception light etc jastrow wrote following summary mr peirce courses logic gave first real experience intellectual muscle though promptly took laboratory


psychology established stanley hall peirce gave first training handling psychological problem time stimulated self esteem entrusting fairly innocent laboratory habits real bit research borrowed apparatus took room installed window conditions illumination right took observations results published joint names ''proceedings national academy sciences'' demonstration traces


sensory effect slight make registry consciousness could none less influence judgment may persistent motive induced years later undertake book ''the subconscious'' work clearly distinguishes observable cognitive performance expression consciousness modern approaches sensory perception research vision hearing touch measure perceiver 's judgment extracts stimulus often putting aside question sensations experienced one leading method based signal detection theory developed cases weak stimuli however subjectivist


approach persists among tradition stanley smith stevens ndash stevens revived idea power law suggested th century researchers contrast fechner 's log linear function cf stevens' power law also advocated assignment numbers ratio strengths stimuli called magnitude estimation stevens added techniques magnitude production cross modality matching opposed assignment stimulus strengths points line labeled order strength nevertheless sort response remained popular applied psychophysics multiple category layouts often


misnamed likert scaling question items used likert create multi item psychometric scales eg seven phrases strongly agree strongly disagree omar khaleefa ref name khaleefa ref argued medieval scientist alhazen considered founder psychophysics although al haytham made many subjective reports regarding vision evidence used quantitative psychophysical techniques claims rebuffed ref name aaenstockdale ref thresholds psychophysicists usually employ experimental stimuli objectively measured pure tones varying intensity lights varying luminance senses studied vision hearing touch including skin


point stimulus change stimulus detected proportion '' p'' occasions detection absolute threshold level intensity stimulus subject able detect presence stimulus proportion time ''p'' level often used example absolute threshold number hairs back one 's hand must touched felt participant may unable feel single hair touched may able


feel two three exceeds threshold absolute threshold also often referred ' 'detection threshold'' several different methods used measuring absolute thresholds discrimination thresholds see discrimination difference threshold noticeable difference jnd magnitude smallest difference two stimuli differing intensities participant able detect proportion time percentage depending kind task test threshold several different methods used subject may asked adjust one stimulus perceived


method adjustment may asked describe direction magnitude difference two stimuli may asked decide whether intensities pair stimuli forced choice noticeable difference jnd fixed quantity rather depends intense stimuli measured particular sense measured weber 's law states noticeable difference stimulus constant proportion despite variation intensity discrimination experiments experimenter seeks determine point difference two


addition two alternative forced choice afc paradigm used assess point performance reduces chance discrimination two alternatives ''p'' typically since ''p'' corresponds chance afc task absolute difference thresholds sometimes considered similar principle always background noise interfering ability detect stimuli ref name snodgrass ref name gescheiderchap ref experimentation psychophysics experiments seek determine whether subject detect stimulus identify differentiate another stimulus describe magnitude nature difference ref name snodgrass ref name gescheiderchap


example experiment testing minimum amplitude sound detected sound begins quietly perceived made gradually louder descending method limits reversed case threshold considered level stimulus property stimuli detected ref name gescheiderchap experiments ascending descending methods used alternately thresholds averaged possible disadvantage methods subject may become accustomed reporting perceive stimulus may continue reporting


way even beyond threshold error habituation conversely subject may also anticipate stimulus become detectable undetectable may make premature judgment error anticipation avoid potential pitfalls georg von b k sy introduced staircase procedure study auditory perception method sound starts audible gets quieter subject 's responses subject report hearing point sound made louder step subject reports hearing


point made quieter steps way experimenter able zero threshold ref name gescheiderchap method constant stimuli instead presented ascending descending order method constant stimuli levels certain property stimulus related one trial next presented randomly prevents subject able predict level next stimulus therefore reduces errors habituation expectation 'absolute thresholds' subject reports whether able detect stimulus ref name gescheiderchap


psychophysical methods classic methods experimentation often argued inefficient advance testing psychometric threshold usually unknown data collected points psychometric function provide little information parameter interest usually threshold adaptive staircase procedures classical method adjustment used points sampled clustered around psychometric threshold data points also spread slightly wider range psychometric function 's slope also interest adaptive methods thus optimized


taken design many different staircase algorithms modeled practical recommendations suggested garcia perez ref name garciaperez ref one common staircase designs fixed step sizes n staircase participant makes correct response n times row stimulus intensity reduced one step size participant makes incorrect response stimulus intensity increased one size threshold estimated mean midpoint runs estimate approaches asymptotically correct threshold bayesian maximum likelihood procedures bayesian maximum likelihood ml adaptive procedures behave


observer 's perspective similar staircase procedures choice next intensity level works differently however observer response set previous stimulus response pairs likelihood calculated threshold lies point maximum likelihood chosen best estimate threshold next stimulus presented level since decision level add information bayesian procedure prior likelihood included calculation ref name treutwein compared staircase procedures bayesian ml procedures


cross modality matching exponents dimensions found numerical magnitude estimation predict exponents found magnitude production magnitude estimation generally finds lower exponents psychophysical function multiple category responses restricted range categorical anchors used likert items attitude scales ref name stevens ref see also medical physics neurophysics behavioral neuroscience psychoacoustics physiological psychology vision science notes references external links http bedienhaptikde themen psychophysik link german website dissertation project animation staircase method transformed staricase method branches psychology cognitive psychology neuroscience


'''welfare economics''' branch economics uses microeconomic techniques evaluate well welfare aggregate economy wide level attempting apply principles welfare economics gives rise field public economics study government might intervene improve social welfare welfare economics also provides theoretical foundations particular instruments public economics including cost benefit analysis combination welfare economics insights behavioral economics led creation new subfield behavioral welfare economics ref name bwe ref field welfare economics associated two fundamental theorems

Social science
Economics
Welfare economics


first states given certain assumptions competitive markets produce pareto efficient outcomes ref name ipe ref captures logic adam smith 's invisible hand ref name mas second states given restrictions pareto efficient outcome supported competitive market equilibrium ref name ipe thus social planner could use social welfare function pick equitable efficient outcome use lump sum transfers followed competitive trade bring ref name ipe ref name mas ref welfare economics' close ties social choice theory arrow 's impossibility theorem sometimes listed third fundamental theorem ref name feldman ref


typical methodology begins derivation assumption social welfare function used rank economically feasible allocations resources terms social welfare entail functions typically include measures economic efficiency equity though recent attempts quantify social welfare included broader range measures including economic freedom capability approach approaches cardinal utility early ''neoclassical approach'' developed edgeworth sidgwick marshall pigou assumes following utility cardinal scale measurable observation judgment preferences


work pareto hicks kaldor explicitly recognizes differences efficiency aspect discipline distribution aspect treats differently questions efficiency assessed criteria pareto efficiency kaldor hicks compensation tests questions income distribution covered social welfare function specification efficiency dispenses cardinal measures utility replacing ordinal utility merely ranks commodity bundles indifference curve map example criteria efficiency situations considered distributive efficiency goods distributed people


gain utility pareto efficiency useful efficiency goal standard economics situation pareto efficient individual made better without making someone else worse example inefficient situation would smith owns apple would prefer consume orange jones owns orange would prefer consume apple could made better trading pareto efficient state affairs come four criteria met marginal rates substitution consumption


two goods identical consumers cannot reallocate goods two consumers make happier marginal rate transformation production two goods identical producers two goods cannot reallocate production two producers increase total output marginal physical product factor input eg labor must producers good cannot reduce production cost reallocating production two producers marginal rates substitution consumption equal marginal rates transformation production


pair goods producers cannot make consumers happier producing one good less number conditions lead inefficiency include imperfect market structures monopoly monopsony oligopoly oligopsony monopolistic competition factor allocation inefficiencies production theory basics externalities asymmetric information including principal agent problems long run declining average costs natural monopoly taxes tariffs government restrictions prices quantities sold regulation resulting government failure note one conditions leads inefficiency another condition might help counteracting


example pollution externality leads overproduction tires tax tires might restore efficient level production condition inefficient first best might desirable second best determine whether activity moving economy towards pareto efficiency two compensation tests developed policy changes usually help people hurting others tests ask would happen winners compensate losers using ''kaldor criterion'' change desirable maximum amount winners would willing pay greater minimum


losers would accept ''hicks criterion'' change desirable maximum losers would willing offer winners prevent change less minimum winners would accept bribe give change hicks compensation test losers' point view kaldor compensation test winners' conditions satisfied proposed change move economy toward pareto optimality idea known kaldor hicks efficiency two conditions disagree yields scitovsky paradox equity


many combinations consumer utility production mixes factor input combinations consistent efficiency fact infinity consumption production equilibria yield pareto optimal results many optima points aggregate production possibility frontier hence pareto efficiency necessary sufficient condition social welfare pareto optimum corresponds different income distribution economy may involve great inequalities income decide pareto optimum desirable decision made either tacitly overtly


specify social welfare function function embodies value judgements interpersonal utility social welfare function shows relative importance individuals comprise society utilitarian welfare function also called benthamite welfare function sums utility individual order obtain society 's overall welfare people treated regardless initial level utility one extra unit utility starving person seen greater value extra unit utility millionaire extreme max min rawlsian utility


function according max min criterion welfare maximized utility society members least greatest economic activity increase social welfare unless improves position society member worst economists specify social welfare functions intermediate two extremes social welfare function typically translated social indifference curves used graphic space functions interact utilitarian social indifference curve linear downward sloping right


max min social indifference curve takes shape two straight lines joined form degree angle social indifference curve drawn intermediate social welfare function curve slopes downward right div style float center image social indifference curves smallpng div intermediate form social indifference curve interpreted showing inequality increases larger improvement utility relatively rich individuals needed compensate loss utility relatively poor individuals crude social welfare function constructed measuring subjective dollar value goods


condition ref name mas direct consequence second theorem benevolent social planner could use system lump sum transfers ensure best pareto efficient allocation supported competitive equilibrium set prices ref name ipe ref name mas generally suggests redistribution possible achieved without affecting prices continue reflect relative scarcity thus ensuring final post trade result efficient put practice policy might resemble predistribution welfare economics' close ties social choice theory arrow 's impossibility theorem sometimes listed


supply demand diagram curve mn social utility frontier point corresponds point c earlier diagram point social utility frontier marginal rate substitution point c equal marginal rate transformation point point e corresponds point b previous diagram lies inside social utility frontier indicating inefficiency mrs point c equal mrt point div style float center file social indifference curve diagramsvg div although points grand social


utility frontier pareto efficient one point identifies social welfare maximized point called point bliss point z social utility frontier mn tangent highest possible social indifference curve labelled si criticisms economists tradition austrian school doubt whether cardinal utility function cardinal social welfare function value reason given difficult aggregate utilities various people differing marginal utility money wealthy poor also


economists austrian school question relevance pareto optimal allocation considering situations framework means ends perfectly known since neoclassical theory always assumes ends means framework perfectly defined value ordinal utility functions questioned economists proposed means measuring well alternative price indices like willingness pay using revealed stated preference method includes subjective well functions based individuals' ratings happiness life satisfaction rather preferences ref name dolan ref price based measures seen promoting


consumerism productivism many possible welfare economics without use prices however always done value assumptions explicit social welfare function used implicit efficiency criterion chosen tend make welfare economics normative perhaps subjective field make controversial however perhaps significant concerns limits utilitarian approach welfare economics according line argument utility thing matters comprehensive approach welfare economics include factors


capability approach theoretical framework entails two core normative claims first claim freedom achieve well primary moral importance second freedom achieve well understood terms people 's capabilities real opportunities reason value see also arrow 's impossibility theorem compensation principle consumer surplus deadweight loss distribution economics economic surplus equity economics feminist economics gini coefficient happiness economics humanistic economics income inequality metrics involuntary unemployment justice economics kaldor hicks efficiency lorenz curve pareto efficiency public interest social safety net


social welfare function universal basic income welfare state world happiness report notes references reading arrow kenneth j nd ed ''social choice individual values'' yale university press new arrow kenneth j g rard debreu ed ''landmark papers general equilibrium theory social choice welfare'' edward elgar publishing description table http wwwe elgarcouk bookentry contentslassoid contents atkinson anthony b ''the economics inequality'' oxford university press london atkinson anthony b ''optimum population welfare economics inequality'' oxford university press london bator francis simple analytics welfare maximization


''american economic review'' https wwwjstororg pss pp calsamiglia xavier alan kirman unique informationally efficient decentralized mechanism fair outcomes ''econometrica'' https wwwjstororg stable pp chipman john james c moore new welfare economics ''international economic review'' https wwwjstororg stable pp mishan e j new welfare economics alternative view ''international economic review'' https wwwjstororg pss pp feldman allan equity ''the new palgrave dictionary economics'' v pp nbsp feldman allan roberto serrano ''welfare economics social choice theory'' nd ed


https booksgooglecom booksid pzv n wwc dq arrow 's theorem source gbs summary cad arrow searchable chapter previews graaff johannes de villiers rev ed ''theoretical welfare economics'' cambridge uk cambridge university press harberger arnold c three basic postulates applied welfare economics interpretive essay ''journal economic literature'' https wwwjstororg stable pp richard et al ''the welfare economics public policy'' edward elgar publishing cheltenham northampton kuenne robert e ed ''readings social welfare theory policy'' wiley description scroll chapter preview https booksgooglecom booksid kmir g njykc printsec frontcover source gbs v summary r cad v onepage q f false links little ''a critique welfare economics'' oxford preview ng yew kwang


rev ed ''welfare economics'' london macmillan o'connell john f ''welfare economic theory'' auburn house publishing boston samuelson paul enlarged ed welfare economics ''foundations economic analysis'' harvard university press cambridge ch viii pp nbsp reaffirming existence 'reasonable' bergson samuelson social welfare functions ''economica'' ns https wwwjstororg pss pp reprinted ''the collected scientific papers paul samuelson'' pp https booksgooglecom booksid ukejec r ac printsec fnd pg pa gbs atb v onepage q f false bergsonian welfare economics rosefielde ed ''economic welfare economics soviet socialism essays honor abram bergson'' cambridge university press cambridge


pp nbsp reprinted ''the collected scientific papers paul samuelson'' https booksgooglecom booksid ukejec r ac printsec fnd pg pa gbs atb v onepage q f false pp sen amartya k distribution transitivity little 's welfare criteria ''economic journal'' https wwwjstororg stable pp ''choice welfare measurement'' mit press description scroll chapter preview https booksgooglecom booksid u gpyet qauc printsec frontcover dq false links suzumura kotaro distributional value judgments piecemeal welfare criteria ''economica'' https wwwjstororg stable pp


siberian tiger zoology '''mammalogy''' study mammals class vertebrates characteristics homeothermic metabolism fur four chambered hearts complex nervous systems ref name ref mammalogy also known '''mastology''' '''theriology''' '''therology''' archive number mammals earth constantly growing currently set different mammal species including recently extinct ref name ref living mammals identified earth roughly newly discovered since ref name major branches mammalogy include natural history taxonomy systematics anatomy physiology ethology ecology

Natural science
Biology
Zoology
Mammalogy


management control approximate salary mammalogist varies year depending experience mammalogists typically involved activities conducting research managing personnel writing proposals ref name ref mammalogy branches taxonomically oriented disciplines primatology study primates cetology study cetaceans like studies mammalogy also part zoology also part biology study living things research purposes mammalogists stated multiple reasons study observation mammals knowing mammals


average make roughly year depends employer state history first people recorded researched mammals ancient greeks records mammals even native greece others aristotle one first recognize whales dolphins mammals since th century study done taxonomy list mammalogy journals list scientific journals broadly serving mammalogists addition many general zoology ecology evolution conservation journals


also deal mammals several journals specific certain taxonomic groups mammals class wikitable sortable journal organization publication schedule impact factor first issue open access page charges online issn print issn former name ''journal mammalogy'' american society mammalogists bimonthly option yes none ''mammal review'' mammal society quarterly option none


''mammalian biology'' german society mammalian biology bimonthly option zeitschrift f r ugetierkunde ''mammalia'' quarterly option none ''mammal research'' polish academy sciences quarterly option x acta theriologica ''mammal study'' mammal society japan quarterly journal mammalogical


none ''acta theriologica sinica'' mammalogical society china quarterly yes none '' http terioshkolaorgua en journalhtm theriologia ukrainica '' ukrainian theriological society biannually yes proceedings theriological school see also list mammalogists references external links https webarchiveorg web http webupacza defaultaspipkcategoryid mammal research institute university pretoria south africa http wwwmammalsocietyorg american society mammalogists subfields zoology


'''reliability engineering''' sub discipline systems engineering emphasizes ability equipment function without failure reliability describes ability system component function stated conditions specified period time reliability closely related availability typically described ability component system function specified moment interval time '' 'reliability''' function theoretically defined probability success time denoted r probability estimated detailed physics failure analysis previous data sets

Applied science
Library and museum studies
Statistics
Reliability Theory


reliability testing reliability modelling availability testability maintainability maintenance often defined part reliability engineering reliability programs reliability often plays key role cost effectiveness systems reliability engineering deals prediction prevention management high levels lifetime engineering uncertainty risks failure although stochastic parameters define affect reliability reliability achieved mathematics statistics nearly teaching literature subject emphasize aspects ignore reality ranges uncertainty involved largely invalidate quantitative methods prediction measurement ref name o'connor o'connor patrick


''practical reliability engineering'' fourth ed john wiley sons new york ref example easy represent probability failure symbol value equation almost impossible predict true magnitude practice massively multivariate equation reliability begin equal accurate predictive measurement reliability reliability engineering relates closely quality engineering safety engineering system safety use common methods analysis may require input said


system must reliably safe reliability engineering focuses costs failure caused system downtime cost spares repair equipment personnel cost warranty claims word ' 'reliability'' traced back first attested poet samuel taylor coleridge world war ii term linked mostly repeatability test type science considered reliable results would obtained repeatedly product improvement use statistical process control promoted dr walter shewhart bell


labs around time waloddi weibull working statistical models fatigue development reliability engineering parallel path quality modern use word reliability defined us military characterizing product would operate expected specified period time world war ii many reliability issues due inherent unreliability electronic equipment available time fatigue issues miner published seminal paper titled cumulative damage fatigue asme journal


main application reliability engineering military vacuum tube used radar systems electronics reliability proved problematic costly ieee formed reliability society united states department defense formed group called advisory group reliability electronic equipment agree investigate reliability methods military equipment group recommended three main ways working improve component reliability establish quality reliability requirements suppliers collect field data find root causes failures emphasis


given reliability testing component system level famous military standard mil std created time around period also much used predecessor military handbook published rca used prediction failure rates electronic components emphasis component reliability empirical research eg mil std alone slowly decreased pragmatic approaches used consumer industries used televisions increasingly made solid state semiconductors automobiles rapidly increased use semiconductors variety microcomputers hood


dash large air conditioning systems developed electronic controllers microwave ovens variety appliances communications systems began adopt electronics replace older mechanical switching systems bellcore issued first consumer prediction methodology telecommunications sae developed similar document sae automotive applications nature predictions evolved decade became apparent die complexity n't factor determined failure rates integrated circuits ics kam wong published paper questioning bathtub curve see also reliability centered maintenance decade failure rate many components


dropped factor software became important reliability systems pace ic development picking wider use stand alone microcomputers common pc market helped keep ic densities following moore 's law doubling every months reliability engineering changing moved towards understanding physics failure failure rates components kept dropping system level issues became prominent systems thinking became important software cmm model capability maturity model developed gave qualitative approach reliability


iso added reliability measures part design development portion certification expansion world wide web created new challenges security trust older problem little reliability information available replaced much information questionable value consumer reliability problems could discussed online real time using data new technologies micro electromechanical systems mems handheld gps hand held devices combined cell phones computers represent challenges maintain reliability product development time continued shorten decade done


failures occur causes corrected apply methods estimating likely reliability new designs analysing reliability data reason priority emphasis far effective way working terms minimizing costs generating reliable products primary skills required therefore ability understand anticipate possible causes failures knowledge prevent also necessary knowledge methods used analysing designs data


maintenance induced failures transport induced failures storage induced failures use load studies component stress analysis derived requirements specification software systematic failures failure reliability testing derived requirements field failure monitoring corrective actions spare parts stocking availability control technical documentation caution warning analysis data information acquisition organisation creation general reliability development hazard log fracas system chaos engineering effective reliability engineering requires understanding basics failure mechanisms experience broad engineering skills good knowledge many different special fields engineering required example tribology stress mechanics fracture mechanics fatigue thermal engineering


fluid mechanics shock loading engineering electrical engineering chemical engineering eg corrosion material science definitions reliability may defined following ways idea item fit purpose respect time capacity designed produced maintained item perform required time capacity population designed produced maintained items perform required time resistance failure item time probability item perform required function stated conditions specified period time durability


projects develop reliability program plan specify reliability tasks statement work sow requirements performed specific system consistent creation safety cases example per arp goal reliability assessments provide robust set qualitative quantitative evidence use component system associated unacceptable risk basic steps take thoroughly identify relevant unreliability hazards eg potential conditions events human errors failure modes interactions failure mechanisms root causes specific analysis tests assess associated system


risk specific analysis testing propose mitigation eg requirements design changes detection logic maintenance training risks may lowered controlled acceptable level determine best mitigation get agreement final acceptable risk levels possibly based cost benefit analysis risk combination probability severity failure incident scenario occurring severity looked system safety system availability point view reliability safety thought different focus reliability system availability availability safety


exist dynamic tension keeping system available unsafe forcing engineering system safe state quickly force false alarms impede availability system ' 'de minimis'' definition severity failures includes cost spare parts man hours logistics damage secondary failures downtime machines may cause production loss complete definition failure also mean injury dismemberment death people within system witness mine accidents industrial accidents space shuttle failures innocent bystanders witness citizenry cities like


best practices tasks methods tools analysis tests required particular sub system well clarify customer requirements reliability assessment large scale complex systems reliability program plan separate document resource determination manpower budgets testing tasks critical successful program general amount work required effective program complex systems large reliability program plan essential achieving high levels reliability testability maintainability resulting system availability developed early system development refined


system 's life cycle specifies reliability engineer also tasks performed stakeholders effective reliability program plan must approved top program management responsible allocation sufficient resources implementation reliability program plan may also used evaluate improve availability system strategy focusing increasing testability maintainability reliability improving maintainability generally easier improving reliability maintainability estimates repair rates also generally accurate however uncertainties reliability estimates


cases large likely dominate availability calculation prediction uncertainty problem even maintainability levels high reliability control complicated issues may arise like manpower maintainers customer service capability shortages spare part availability logistic delays lack repair facilities extensive retro fit complex configuration management costs others problem unreliability may increased also due domino effect maintenance induced failures repairs focusing maintainability therefore enough failures prevented none issues importance therefore


reliability generally regarded important part availability reliability needs evaluated improved related availability total cost ownership tco due cost spare parts maintenance man hours transport costs storage cost part obsolete risks etc gm toyota belatedly discovered tco also includes downstream liability costs reliability calculations sufficiently accurately addressed customers' personal bodily risks often trade needed two might maximum ratio availability cost ownership testability


cost translates even minor increase availability unavailability platform results massive loss revenue easily exceed high cost ownership proper reliability plan always address ramt analysis total context ramt stands reliability availability maintainability maintenance testability context customer 's needs reliability requirements system one first tasks reliability engineering adequately specify reliability maintainability requirements allocated overall availability needs importantly derived proper design failure analysis


preliminary prototype test results clear requirements able designed constrain designers designing particular unreliable items constructions interfaces systems setting availability reliability testability maintainability targets eg max failure rates appropriate broad misunderstanding reliability requirements engineering reliability requirements address system including test assessment requirements associated tasks documentation reliability requirements included appropriate system subsystem requirements specifications test plans contract statements creation proper lower level requirements critical references group todinov mt reliability


risk models setting reliability requirements wiley provision quantitative minimum targets eg mean time failure mtbf values failure rates sufficient different reasons one reason full validation related correctness verifiability time quantitative reliability allocation requirement spec lower levels complex systems often made consequence fact requirements probabilistic extremely high level uncertainties involved showing compliance probabilistic requirements reliability function time accurate


terms mtbf far uncertain design parameters design furthermore reliability design requirements drive system part design incorporate features prevent failures occurring limit consequences failure first place would aid predictions effort would keep distracting engineering effort kind accounting work design requirement precise enough designer design also prove analysis testing requirement achieved possible within stated confidence


type reliability requirement detailed could derived failure analysis finite element stress fatigue analysis reliability hazard analysis fta fmea human factor analysis functional hazard analysis etc type reliability testing also requirements needed verification tests eg required overload stresses test time needed derive requirements effective manner systems engineering based risk assessment mitigation logic used robust hazard log systems must created contain detailed information systems could failed requirements derived


tracked way practical design requirements shall drive design used verification purposes requirements often design constraints way derived failure analysis preliminary tests understanding difference compared purely quantitative logistic requirement specification eg failure rate mtbf target paramount development successful complex systems maintainability requirements address costs repairs well repair time testability confused test requirements requirements provide link reliability maintainability address detectability


failure modes particular system level isolation levels creation diagnostics procedures references group todinov mt reliability risk models setting reliability requirements wiley indicated reliability engineers also address requirements various reliability tasks documentation system development testing production operation requirements generally specified contract statement work depend much leeway customer wishes provide contractor reliability tasks include various analyses planning failure reporting task selection depends criticality system well cost


safety critical system may require formal failure reporting review process throughout development whereas non critical system may rely final test reports common reliability program tasks documented reliability program standards mil std ieee failure reporting analysis corrective action systems common approach product process reliability monitoring reliability culture human errors human factors practice failures traced back type human error example management decisions eg budgeting timing required tasks systems engineering use studies load


cases systems engineering requirement analysis setting systems engineering configuration control assumptions calculations simulations fem analysis design design drawings testing eg incorrect load settings failure measurement statistical analysis manufacturing quality control maintenance maintenance manuals training classifying ordering information feedback field information eg incorrect vague etc however humans also good detecting failures correcting improvising abnormal situations occur therefore policies completely rule human actions design production processes improve reliability may effective tasks better performed humans


better performed machines furthermore human errors management organization data information misuse abuse items may also contribute unreliability core reason high levels reliability complex systems achieved following robust systems engineering process proper planning execution validation verification tasks also includes careful organization data information sharing creating reliability culture way safety culture paramount development safety critical systems reliability prediction


costly addition argue prediction reliability historic data misleading comparisons valid identical designs products manufacturing processes maintenance identical operating loads usage environments even minor changes could major effects reliability furthermore unreliable important items ie interesting candidates reliability investigation likely modified engineered since historical data gathered making standard active pro active statistical methods processes used eg medical insurance industries less effective another


surprising logical argument able accurately predict reliability testing exact mechanisms failure must known therefore cases could prevented following incorrect route trying quantify solve complex reliability engineering problem terms mtbf probability using incorrect example active approach referred barnard playing numbers game regarded bad practice ref name lambda ref existing systems arguable attempt responsible program correct root


cause discovered failures may render initial mtbf estimate invalid new assumptions subject high error levels effect correction must made another practical issue general unavailability detailed failure data available often featuring inconsistent filtering failure feedback data ignoring statistical errors high rare events like reliability related failures clear guidelines must present count compare failures related different type root causes eg manufacturing maintenance transport system induced inherent design failures comparing different types causes may lead


incorrect estimations incorrect business decisions focus improvement perform proper quantitative reliability prediction systems may difficult expensive done testing individual part level reliability results often obtained comparatively high confidence testing many sample parts might possible using available testing budget however unfortunately tests may lack validity system level due assumptions made part level testing authors emphasized importance initial part system level testing failure learn failures improve system part


general conclusion drawn accurate absolute prediction either field data comparison testing reliability cases possible exception might failures due wear problems fatigue failures introduction mil std written reliability prediction used great caution used solely comparison trade studies design reliability design reliability dfr process encompasses tools procedures ensure product meets reliability requirements use environment duration


lifetime dfr implemented design stage product proactively improve product reliability dfr often used part overall design excellence dfx strategy statistics based approach ie mtbf reliability design begins development system model reliability availability models use block diagrams fault tree analysis provide graphical means evaluating relationships different parts system models may incorporate predictions based failure rates taken historical data input data predictions often accurate absolute sense valuable


assess relative differences design alternatives maintainability parameters example mean time repair mttr also used inputs models important fundamental initiating causes failure mechanisms identified analyzed engineering tools diverse set practical guidance performance reliability provided designers generate low stressed designs products protect protected damage excessive wear proper validation input loads requirements may needed addition verification reliability performance testing fault tree diagram


one important design techniques redundancy means one part system fails alternate success path backup system reason ultimate design choice related fact high confidence reliability evidence new parts systems often available extremely expensive obtain combining redundancy together high level failure monitoring avoidance common cause failures even system relatively poor single channel part reliability made highly reliable system level


mission critical reliability testing reliability required conjunction redundancy use dissimilar designs manufacturing processes eg via different suppliers similar parts single independent channels provide less sensitivity quality issues eg early childhood failures single supplier allowing high levels reliability achieved moments development cycle early life long term redundancy also applied systems engineering double checking requirements data designs calculations software tests overcome systematic failures another effective way deal


reliability issues perform analysis predicts degradation enabling prevention unscheduled downtime events failures rcm reliability centered maintenance programs used physics failure based approach electronic assemblies increasing shift towards different approach called physics failure technique relies understanding physical static dynamic failure mechanisms accounts variation load strength stress lead failure high level detail made possible use modern finite element method fem software programs handle complex geometries mechanisms


ffa predictive preventive maintenance reliability centered maintenance rcm analysis testability analysis failure diagnostics analysis normally also incorporated fmea human error analysis operational hazard analysis preventative planned maintenance optimization pmo manual screening integrated logistics support results methods presented reviews part system design logistics reliability one requirement among many complex part system engineering trade studies used determine optimum balance reliability requirements constraints importance language reliability engineers whether using quantitative qualitative methods describe failure hazard


failure occurred eg due stressed components manufacturing issues far likely lead improvement designs processes used ref name o'connor quantifying failure likely occur eg via determining mtbf first reliability hazards relating part system need classified ordered based form qualitative quantitative logic possible allow efficient assessment eventual improvement partly done pure language proposition logic also based experience similar items


example seen descriptions events fault tree analysis fmea analysis hazard tracking logs sense language proper grammar part qualitative analysis plays important role reliability engineering like safety engineering general within systems engineering correct use language also key identifying reducing risks human error often root cause many failures include proper instructions maintenance manuals operation manuals emergency procedures others prevent systematic human errors may result system failures


written trained experienced technical authors using called simplified english simplified technical english words structure specifically chosen created reduce ambiguity risk confusion eg replace old part could ambiguously refer swapping worn part non worn part replacing part one using recent hopefully improved design reliability modeling reliability modeling process predicting understanding reliability component system prior implementation two types analysis often used model


complete system 's availability behavior including effects logistics issues like spare part provisioning transport manpower fault tree analysis reliability block diagrams component level types analyses used together others input models come many sources including testing prior operational experience field data well data handbooks similar related industries regardless source model input data must used great caution predictions valid cases product used context predictions


often used help compare alternatives reliability block diagram showing oo redundant designed subsystem part level predictions two separate fields investigation common physics failure approach uses understanding physical failure mechanisms involved mechanical crack propagation chemical corrosion degradation failure parts stress modelling approach empirical method prediction based counting number type components system stress undergo operation reliability theory reliability defined probability device


perform intended function specified period time stated conditions mathematically may expressed math display block r pr int infty f x dx math math f x math failure probability density function math math length period time assumed start time zero key elements definition reliability predicated intended function generally taken mean operation without failure however even individual part system fails system whole intended


still charged system reliability system requirements specification criterion reliability measured reliability applies specified period time practical terms means system specified chance operate without failure time math math reliability engineering ensures components materials meet requirements specified time note units time may sometimes used eg mission operation cycles reliability restricted operation stated explicitly defined conditions constraint necessary


impossible design system unlimited conditions mars rover different specified conditions family car operating environment must addressed design testing rover may required operate varying conditions requiring additional scrutiny two notable references reliability theory mathematical statistical foundations barlow r e proschan f samaniego f j quantitative system reliability parameters theory quantitative requirements specified using reliability parameters common reliability parameter mean time failure mttf also


specified failure rate expressed frequency conditional probability density function pdf number failures given period parameters may useful higher system levels systems operated frequently ie vehicles machinery electronic equipment reliability increases mttf increases mttf usually specified hours also used units measurement miles cycles using mttf values lower system levels misleading especially specify associated failures modes mechanisms f


mttf ref name referencea cases reliability specified probability mission success example reliability scheduled aircraft flight specified dimensionless probability percentage often used system safety engineering special case mission success single shot device system devices systems remain relatively dormant operate examples include automobile airbags thermal batteries missiles single shot reliability specified probability one time success subsumed related parameter single shot missile reliability may specified requirement


confidence intervals reliability testing purpose reliability testing discover potential problems design early possible ultimately provide confidence system meets reliability requirements reliability testing may performed several levels different types testing complex systems may tested component circuit board unit assembly subsystem system levels test level nomenclature varies among applications example performing environmental stress screening tests lower levels piece parts small assemblies catches problems cause failures higher levels testing proceeds


level integration full system testing developmental testing operational testing thereby reducing program risk however testing mitigate unreliability risk test statistical type type error could made depends sample size test time assumptions needed discrimination ratio risk incorrectly accepting bad design type error risk incorrectly rejecting good design type error always feasible test system requirements systems prohibitively expensive test failure modes may take years


observe complex interactions result huge number possible test cases tests require use limited test ranges resources cases different approaches testing used highly accelerated life testing design experiments simulations desired level statistical confidence also plays role reliability testing statistical confidence increased increasing either test time number items tested reliability test plans designed achieve specified reliability specified confidence level minimum number test units test


time different test plans result different levels risk producer consumer desired reliability statistical confidence risk levels side influence ultimate test plan customer developer agree advance reliability requirements tested key aspect reliability testing define failure although may seem obvious many situations clear whether failure really fault system variations test conditions operator differences weather unexpected situations create differences customer system developer one


strategy address issue use scoring conference process scoring conference includes representatives customer developer test organization reliability organization sometimes independent observers scoring conference process defined statement work test case considered group scored success failure scoring official result used reliability engineer part requirements phase reliability engineer develops test strategy customer test strategy makes trade offs needs reliability organization wants


failure probability failure mode effect needs justified evidence generated level confidence testing software based systems probability mix software hardware based failures testing reliability requirements problematic several reasons single test cases insufficient generate enough statistical data multiple tests long duration tests usually expensive tests simply impractical environmental conditions hard predict systems life cycle reliability engineering used design realistic affordable test program provides empirical evidence system


meets reliability requirements statistical confidence levels used address concerns certain parameter expressed along corresponding confidence level example mtbf hours confidence level specification reliability engineer example design test explicit criteria number hours number failures requirement met failed different sorts tests possible combination required reliability level required confidence level greatly affects development cost risk customer producer care


induce field failure laboratory much faster rate providing harsher nonetheless representative environment test product expected fail lab would failed field much less time main objective accelerated test either following discover failure modes predict normal field life high stress lab life accelerated testing program broken following steps define objective scope test collect required information product identify


stress es determine level stress es conduct accelerated test analyze collected data common ways determine life stress relationship arrhenius model eyring model inverse power law model temperature humidity model temperature non thermal model software reliability software reliability special aspect reliability engineering system reliability definition includes parts system including hardware software supporting infrastructure including critical external interfaces operators procedures traditionally reliability engineering focuses critical hardware parts system since widespread use digital integrated circuit technology software become increasingly critical part


electronics hence nearly present day systems significant differences however software hardware behave hardware unreliability result component material failure results system performing intended function repairing replacing hardware component restores system original operating state however software fail sense hardware fails instead software unreliability result unanticipated results software operations even relatively small software programs astronomically large combinations inputs states infeasible exhaustively test


restoring software original state works combination inputs states results unintended result software reliability engineering must take account despite difference source failure software hardware several software reliability models based statistics proposed quantify experience software longer software run higher probability eventually used untested manner exhibit latent defect results failure shooman musa denney hardware software reliability depends


good requirements design implementation software reliability engineering relies heavily disciplined software engineering process anticipate design unintended consequences overlap software quality engineering software reliability engineering hardware quality reliability good software development plan key aspect software reliability program software development plan describes design coding standards peer reviews unit tests configuration management software metrics software models used software development common reliability metric number software faults usually expressed faults per thousand lines


code metric along software execution time key software reliability models estimates theory software reliability increases number faults fault density decreases establishing direct connection fault density mean time failure difficult however way software faults distributed code severity probability combination inputs necessary encounter fault nevertheless fault density serves useful indicator reliability engineer software metrics complexity also used metric remains controversial since


changes software development verification practices dramatic impact overall defect rates testing even important software hardware even best software development process results software faults nearly undetectable tested hardware software tested several levels starting individual units integration full system testing unlike hardware inadvisable skip levels software testing phases testing software faults discovered corrected tested reliability estimates updated based fault density metrics system level mean time failure