Bit By Bit - Misa tshebedisano - 5.2.1 Galaxy Zoo
Galaxy Zoo kopanya boiteko ba baithaopi ba bangata bao e seng setsebi ho bee sehlopheng milione lihlopha tsa linaleli.
Galaxy Zoo hōla tsoa bothata tobana ke Kevin Schawinski, seithuti se fumaneng lengolo thutong ea linaleli Univesithing ea Oxford a 2007. nolofatsa haholo a batla a, Schawinski ne a thahasella ho lihlopha tsa linaleli, 'me lihlopha tsa linaleli ka classified ke bona phetoho-elliptical kapa spiral-le ke bona mebala ea tsona-a maputsoa kapa o mofubelu. Ka nako eo, bohlale bo tloaelehileng har'a litsebi tsa linaleli e ne e le lihlopha tsa linaleli tse spiral, joaloka rona Milky Way, e ne e le boputsoa bo ka 'mala (bocheng bontšang) le hore lihlopha tsa linaleli tse elliptical ne mofubelu ka' mala (bontšang botsofali). Schawinski belaela bohlale boo tloaelehileng. O belaela hore le hoja paterone ena ka 'na ba' nete ka kakaretso, ho ne ho ka etsahala hore ebe e sizable palo ya ntle le mabaka a, 'me seo ka ho ithuta lotho ea lihlopha tsa linaleli-e leng tsena e sa tloaelehang ba ne ba sa lumellane le ho lebeletsoe paterone-o ne a ka ithuta ho hong ka tshebetso eo ka yona lihlopha tsa linaleli thehoa.
Ka hona, seo Schawinski hlokahalang e le hore ho phethola bohlale ba tloaelehileng e ne e le sete e kholo ea lihlopha tsa linaleli morphologically arologantsweng; ke hore, lihlopha tsa linaleli tse neng li classified e le e ka ba spiral kapa elliptical. Bothata Leha ho le joalo, e ne e le mekhoa e teng algorithmic bakeng tlhophiso e ne e se leha ho le joalo ho a lekana ho sebediswa bakeng sa lipatlisiso tsa saense; ka mantsoe a mang, di baya ka ditlhopha melala e ne e ka nako eo, bothata boo ne ho le thata bakeng sa lik'homphieutha. Ka hona, seo ho ne ho hlokahala e ne e le palo e kholo ea botho classified lihlopha tsa linaleli. Schawinski ba etsa bothata bona tlhophiso le lebaka la cheseho ea seithuti sa kalogo. Ka marathone fa setlhopha se kopane e fihle ho supa, 12 matsatsi a lihora tse, o ne a khona ho bee sehlopheng melala 50,000. Ha a ntse a melala 50,000 ka 'na utloahala eka ngata, ho ha e le hantle feela ka 5% ea hoo e ka bang milione lihlopha tsa linaleli tse neng li fota ka Sloan Digital Sky Survey. Schawinski hlokomela hore o hloka mokhoa o eketsehileng scalable.
Ka lehlohonolo, ho fellang kateng le hore mosebetsi oa ho di baya ka ditlhopha lihlopha tsa linaleli ha a hloke koetliso ea e tsoetseng pele thutong ea linaleli; u ka ruta motho ho etsa hore se be setle ka potlako. Ka mantsoe a mang, le hoja di baya ka ditlhopha lihlopha tsa linaleli ke mosebetsi o neng o boima bakeng sa lik'homphieutha, ho ne ho e ntle bonolo hore batho. Kahoo, ha a lutse ka pub a Oxford, Schawinski tsa habo tsona le setsebi sa linaleli Chris Lintott lora ka e ho website ya moo baithaopi ba ne ba bee sehlopheng litšoantšo tsa lihlopha tsa linaleli. Likhoeli tse seng kae hamorao, Galaxy Zoo ile a hlaha.
At setsheng sa inthanete Galaxy Zoo, baithaopi ba ne ba feta metsotso e seng mekae ea ho koetlisa; Ka mohlala, ho ithuta phapang pakeng tsa spiral le elliptical galaxy (Figure 5.2). Ka mor'a hore koetliso ena, baithaopi ile ka tlameha ho feta ba bonolo ba nonya-nepo di baya ka ditlhopha 11 of 15 lihlopha tsa linaleli le tsejoa classifications-joale e ntan'o ba moithaopi tla qala tlhophiso ea sebele ea lihlopha tsa linaleli sa tsejoeng ka tsela e itekanetseng e ho web thehiloeng segokanyimmediamentsi sa sebolokigolo (Figure 5.3 go). Phetoho ea ho tloha moithaopi ho setsebi sa linaleli li tla etsahala ka mor'a metsotso e ka tlase ho 10 le feela e hlokehang ho fetisetsa tse tlaase-tlaase tsa mathata, e nonya maikutlo bonolo.
Figure 5.2: Mehlala ea mefuta e 'meli e ka sehloohong ea lihlopha tsa linaleli: spiral le elliptical. Ngoe kahong eo Galaxy Zoo sebelisoa ho feta 100,000 baithaopi ho dihlopha tse fetang 900.000 litšoantšo. Source: www.galaxyzoo.org .
Figure 5.3 go: Keletso skrine moo bakgethi ile ra kōptjoa ho bee sehlopheng setšoantšo se nang balekane. Source: www.galaxyzoo.org .
Galaxy Zoo khahloa baithaopi yona lekgetlo la ntlha ka mor'a morero o ile a hlahisa sehloohong o mong oa litaba, 'me e ka bang ka likhoeli tse tšeletseng morero hōla ho akarelletsa ho feta 100,000 moahi-rasaense, batho ba neng ba kopanela hobane ba ne ba thabela mosebetsi' me ba batla ho thusa esale pele botsebi ba linaleli. Hammoho, baithaopi bana ba 100,000 tlatselitse kakaretso ea classifications ba fetang limilione tse 40, le boholo ba classifications e tlang ho tswa ho fokolang, sehlopha konokono tsa barupeluoa (Lintott et al. 2008) .
Bafuputsi ba na le phihlelo hira bathusi etsa lipatlisiso basenadikerii ka 'na hang-hang ba belaela hore ho ka boleng ya data. Ha a ntse a belaella sena ke kahlolo e molemo, Galaxy Zoo bontša hore ha menehelo moithaopi ba nepo hloekisa, debiased, 'me kopanya palokakaretso, ba ka hlahisa litholoana boleng bo phahameng (Lintott et al. 2008) . An qhekella le habohlokoa hore ho bongata ho bōpa profeshenale ya data boleng ke redundancy; ke hore, kaha mosebetsi tšoanang e etsoang ke batho ba bangata e fapaneng. A Galaxy Zoo, ho ne ho ka bang 40 classifications ka galaxy; bafuputsi ba sebelisa bathusi etsa lipatlisiso basenadikerii ka mohla khona ho bophahamo ba ee ea redundancy 'me ka hona lokela ho ho hongata amehile haholo ka boleng ba mong le e mong tlhophiso ka bomong. Seo baithaopi haelloa a koetlisoa ka thata, ba entsoeng ka etsoe ba nang le redundancy.
Esita le classifications multiple ka galaxy Leha ho le joalo, kopantseng e behiloeng ea classifications moithaopi ho hlahisa be betere nakong e tlhophiso ke a qhekellang. Hobane mathata a tšoanang haholo hlaha mererong fetisisa go balelela batho, ho molemo ho hlahlobeng ho se hokae mehato e meraro eo ea bafuputsi Galaxy Zoo sebelisoa ho hlahisa batla tumellano classifications bona. Taba ea pele, bafuputsi "hloekisa" boitsebiso ka ho tlosa classifications bogus. Ka mohlala, batho ba pheta-pheta classified e le 'ngoe galaxy-e leng ntho e neng e tla etsahala haeba ba ne ba leka ho laola ho bile le litholoana-o ne a classifications tsohle tsa bona tse lahliloeng. Ena le tse ling tse tšoanang ho hloekisa tlosa mabapi 4% ea classifications tsohle.
Ea bobeli, ka mor'a hore ho hloekisa, bafuputsi ba ne ba hloka ho tlosa biases e laolehileng ka classifications. A sebelisa letoto la lithuto tsa leeme phumano aa ageletsweng ka hara mantlha mohlala projeke-ka, ho bontša le baithaopi ba bang sena sa linaleli ka mosoeu ho e-na tse mebala-ebang bafuputsi fumana biases 'maloa e laolehileng, tse kang leeme ka thulaganyo ho bee sehlopheng melala hōle spiral joalokaha melala elliptical (Bamford et al. 2009) . Tloaela bakeng biases tsena ka tsela e hlophisitsoeng ke ea bohlokoa haholo hobane e leng karolelano ea menehelo e mengata ha le e tlose leeme ka tsela e hlophisitsoeng; ho hlokahala feela tlosa phoso khethe.
Qetellong, ka mor'a debiasing, bafuputsi ba ne ba hloka mokhoa ho kopana ea classifications motho ka mong ho hlahisa be betere nakong e tlhophiso. Tsela eo bonolo ho kopana classifications mong le e mong galaxy ne e tla ba ho khetha tlhophiso atileng ka ho fetisisa. Leha ho le joalo, mokhoa ona e ne e tla fana ka mong le e mong oa boithaopo bo lekanang, 'me bafuputsi ba belaela hore baithaopi ba ka bang ba ne ba molemo ho tlhophiso feta ba bang. Ka hona, bafuputsi ba tsa qapa rarahaneng haholoanyane iterative bokete Tsamaiso e hore leka ho ka tsela e iketsang khona ho utloa ho classifiers molemo ka ho fetisisa le ba fa boima ho feta.
Kahoo, ka mor'a hore a tsamaise mehato ea tse tharo tiriso ya thulaganyo-ke hloekisa, debiasing, 'me boima bo-e leng Galaxy Zoo thimi etsa lipatlisiso sokolohetseng limilione tse 40 tsa baithaopi classifications ho kena sete ya batla tumellano classifications morphological. Ha tsena classifications Galaxy Zoo ne ba bapisoa le boiteko ba bararo mehleng tse nyenyane tse ka tekanyo e ke litsebi tsa linaleli profeshenale, ho akarelletsa le tlhophiso ka Schawinski hore thusitse ho bululela Galaxy Zoo, ho ne ho le matla tumellano. Kahoo, baithaopi, a aggregate, ba ile ba khona ho fana ka classifications boleng bo phahameng 'me ka tekanyo e nepahetseng tseo babatlisisi ba ne ba ke ke tšoanang le (Lintott et al. 2008) . Ha e le hantle, ka ho ba le classifications botho bakeng sa palo e kholo e joalo ea lihlopha tsa linaleli, Schawinski, Lintott le ba bang ba ile ba khona ho bontša hore e ka bang 80% ea lihlopha tsa linaleli latela lebeletsoe paterone-botala ikhara hona le ellipticals-khubelu lipampiri tse ngata li ngotsoe hoo e ka bang sibolloa ena (Fortson et al. 2011) .
Fuoa semelo sena, re ka hona joale re bone kamoo Galaxy Zoo latela petsoha-amang-kopana risepe, e leng risepe e tšoanang le eo e sebelisitsoe bakeng sa diporojeke fetisisa go balelela batho. Taba ea pele, ke tlisa jwang mathata khōlō e aroha chunks. Tabeng ena, bothata ba di baya ka ditlhopha milione melala e aroha e mathata a limilione tse di baya ka ditlhopha galaxy le 'ngoe. Ka mor'a moo, buuoa e sebelisoa ho e mong le e chunk nosi. Tabeng ena, moithaopi e ne e tla bee sehlopheng mong le e mong galaxy joalokaha mohlomong spiral kapa elliptical. Qetellong, liphello e ba ho kopantswe ho hlahisa lebaka tumellano. Tabeng ena, ea kopana bohato ba akarelletsa ho hloekisa, ho debiasing, 'me boima bo ho hlahisa be betere nakong e tlhophiso mong le e mong galaxy. Le hoja diporojeke fetisisa sebelisa risepe ena kakaretso, nngwe le nngwe ya mehato e lokela ho customized ho bothata tse tobileng tseo ba lebisitsoe. Ka mohlala, ka tsela eo batho balelela projeke hlalosoa mona ka tlase, e risepe e tšoanang e tla lateloa, empa etsa le kopana mehato e tla ba fapane haholo.
Bakeng sa thimi Galaxy Zoo, morero ona pele e ne e mpa e le qalo feela. Ka pele haholo ba hlokomela hore le hoja ba ne ba khona ho bee sehlopheng haufi le lihlopha tsa linaleli tse limilione tse, tekanyo e sena ha hoa lekana ho sebetsa le liphuputso tse ncha dijethale sepakapakeng, e leng ne a ka hlahisa litšoantšo ba ka bang limilione tse likete tse 10 le lihlopha tse (Kuminski et al. 2014) . Ho sebetsana le keketseho e tsoang limilione tse 1 ho isa ho 10 limilione tse likete tse-le palokatiso ya 10,000-Galaxy Zoo tla lokela ho e tsoma badiri le kakanyo feela e ka makhetlo 10,000 ho feta barupeluoa. Le hoja palo ea baithaopi ho Internet o moholo, hase lekanngoa. Ka hona, bafuputsi ba tsa hlokomela hore haeba ba eang ho sebetsana leha e le neng hōla bokae ya data, o mocha, o le ho feta scalable, mokhoa ho ne ho hlokahala.
Ka lebaka leo, Manda Banerji-sebetsa le Kevin Schawinski, Chris Lintott, 'me litho tse ling tsa Galaxy Zoo thimi-ho qala lik'homphieutha ruta ho bee sehlopheng lihlopha tsa linaleli. More ka ho toba, a sebelisa classifications botho bōpiloe ke Galaxy Zoo, Banerji et al. (2010) haha mochine ithuta ea mohlala e neng e ka noha tlhophiso botho tsa linaleli e thehiloeng litšobotsi tsa setšoantšo. Haeba sena mochine ithuta ea mohlala ka ikatisa ea classifications botho ka ho nepahala phahameng, joale ho ne ho ka sebelisoa ke bafuputsi Galaxy Zoo ho bee sehlopheng palo e le hantle ke keng ba lekanngoa ba lihlopha tsa linaleli.
Mesebetsi ea mantlha ea ho atamela Banerji le basebetsi-'moho 'ha e le hantle le ntle tšoanang le dithekniki sebediswang ka mehla a etsa lipatlisiso tsa phedisano, le hoja eo tšoana ka' na se ke ua hlakileng nakong habanya taba. Taba ea pele, Banerji le basebetsi-'moho sokoloha mong le e mong setšoantšo sa ho kena sete ya ditshebetso tse sa dinomoro hore akaretsa ho thepa ea bona. Ka mohlala, bakeng sa litšoantšo tsa lihlopha tsa linaleli ho na le ditshebetso tse tharo: tjhelete ya a maputsoa a setšoantšo, e leng lumellane ha a ee khanyeng ea dipikselse, 'me palo ea dipikselse non-tšoeu. Tlhopho ya ditshebetso tse nepahetseng ke karolo ea bohlokoa ea bothata, 'me e ka kakaretso e hloka ho ipeha tlas'a-sebakeng sa bokgoni. Mohato ona oa pele, ka tloaelo ho thoeng tšobotsi boenjiniere, fella ka popeho ya data le moleng o le mong ka setšoantšo 'me joale a mararo litšiea hlalosa hore setšoantšo se qalong. Fuoa popeho ya data le khumo lakatsa (mohlala, ebang setšoantšo ile classified ke batho joalokaha e galaxy elliptical), eo e leng mofuputsi ea hakanya meedi ya dipalopalo ea mohlala-ka mohlala, ho hong ho kang logistic bofokoli-hore o bolela esale pele go baya botho thehiloeng ka libopeho tsa setšoantšo. Qetellong, eo e leng mofuputsi ea sebelisa entsprechen a ea mohlala ena dipalopalo ho hlahisa hakanngoa classifications ea lihlopha tsa linaleli tse ncha (Figure 5.4). Ho nahana ka analoge tsoang sechabeng, nka hore u tlameha u fumane boitsebiso bo babapatsi mabapi liithuti tse milione, 'me u tsebe hore na ba qeta k'holejeng kapa che. U ka lumellane e bofokoli logistic ho data ya ena, 'me ka nako eo o ne a ka sebelisa sephetho entsprechen ea mohlala ho noha hore na liithuti tse ncha tsa eang ho qeta k'holejeng. Ka ho ithuta, mochine o mokhoa ona-ho sebelisa ngotsweng mehlala ho bopa dipalopalo ea mohlala eo ka nako eo nka e ncha ya data-o bitsoa leihlo ithuta (Hastie, Tibshirani, and Friedman 2009) .
Figure 5.4: KHATISO tlhaloso ea hore na Banerji et al. (2010) o ile a sebelisa Galaxy Zoo classifications ho koetlisa mochine ithuta ea mohlala ho etsa tlhophiso galaxy. Litšoantšo tsa lihlopha tsa linaleli li ne li fetoloa ka popeho ya dikarolo. Ka mohlala lena le nolofalitsoeng ho na le ditshebetso tse tharo (tjhelete ya bolou ka setšoantšo, e leng lumellane ha a ee khanyeng ea dipikselse, 'me palo ea dipikselse non-o mosoeu). Joale, bakeng sa karolo ea litšoantšo, e leng se ngotsweng Galaxy Zoo li sebelisetsoa ho koetlisa a beha mohlala o mochine ithuta. Qetellong, ho ithuta mochine e sebelisoa ho hakanya classifications bakeng sa lihlopha tsa linaleli tse setseng. Ke hoeletsa mofuta ona morero bobeli molokong o mong ka dikhomphuitha botho projeke hobane, ho e-na ho ba le batho ba rarolla bothata, ba e-na batho haha ​​sete ea datha hore e ka sebediswa ho koetlisa k'homphieutha ho rarolla bothata boo. Ka ba molemo ho mokhoa ona k'homphieutha a thusa ke hore e thusa u ho sebetsana bokae hantle ke keng ba lekanngoa ya data sebelisa feela lekanyelitsoeng palo ya boiteko ba motho.
Ditshebetso tse Banerji et al. (2010) mochine ithuta ea mohlala e ne e rarahane ho feta batho ba lipopi ba ka mohlala-ka mohlala, o ile a sebelisa litsobotsi tse ling tšoana le "de Khao Vaucouleurs lumellane axial karo-karolelano" -le ea mohlala hae e ne e se logistic bofokoli, e ne e le tsa maiketsetso neural netweke. U sebelisa litsobotsi tse ling hae, ea mohlala ea hae, 'me ba lumellana Galaxy Zoo classifications, o ile a khona ho theha litekanyo ka' ngoe tsobotsi, 'me joale sebelisa litekanyo tsena ho etsa tse boletsoeng esale pele ka go baya lihlopha tsa linaleli. Ka mohlala, Analysis hae ile a fumana hore litšoantšo le tlaase "de Khao Vaucouleurs lumellane axial karo-karolelano" e ne e ka etsahala ho ba spiral lihlopha tsa linaleli. Fuoa litekanyo tsena, o ile a khona ho noha tlhophiso botho tsa linaleli sa ka ho nepahala le kahlolo e molemo.
Mosebetsi oa Banerji et al. (2010) reteleha Galaxy Zoo sa seo ke tla bitsa bobeli molokong o mong ka balelela botho tsamaiso. Tsela e molemohali ea ho nahana ka litsamaiso tsena bobeli molokong o mong ka ke hore ho e-na ho ba le batho ba rarolla bothata, ba e-na batho haha ​​sete ea datha hore e ka sebediswa ho koetlisa k'homphieutha ho rarolla bothata boo. Ka tjhelete e ya data ho hlokahala hore a koetlise k'homphieutha ho ka ba moholo hoo e hloka e le motho boima tshebedisano ho bopa. Tabeng ea Galaxy Zoo, e marangrang neural sebelisoa ke Banerji et al. (2010) e hlokehang palo e khōlō haholo ka mehlala ea batho-ngotsweng e le hore a hahe ea mohlala eo o ile a khona ho tshepahala ikatisa ya tlhophiso ea batho.
Ka ba molemo ho mokhoa ona k'homphieutha a thusa ke hore e thusa u ho sebetsana bokae hantle ke keng ba lekanngoa ya data sebelisa feela lekanyelitsoeng palo ya boiteko ba motho. Ka mohlala, mofuputsi e mong o na le milione ea batho classified lihlopha tsa linaleli ka haha ​​lepa ea mohlala eo ka nako eo e sebelisoa ho bee sehlopheng bilione kapa esita le lihlopha tsa linaleli tse libilione tse. Haeba ho na le dinomoro tsa tonanahali tsa lihlopha tsa linaleli, joale mofuta ona tsa botho-khomphuteng ya lebasetere e le hantle e leng bona feela ba tharollo. Sena se scalability ke keng ba lekanngoa ha a free, leha ho le joalo. Ho haha mochine ithuta mohlala eo ka nepo ikatisa ea classifications motho ha o ka boeona le bothata ka thata, empa ka lehlohonolo ho na le ba se a ntse a libuka e babatsehang ea neheloa ho sehlooho sena (Hastie, Tibshirani, and Friedman 2009; Murphy 2012; James et al. 2013) .
Galaxy Zoo bontša hore lintho li iphetotse ea merero e mengata balelela batho. Taba ea pele, eo e leng mofuputsi e leka morero ke hore eena ka boeena kapa ka thimi e nyenyane ea bathusi ba etsa lipatlisiso (mohlala, Schawinski hore qalong tlhophiso ho bapala ka matla). Haeba mokhoa ona ha hloa hantle, mofuputsi e ka fallela palelelo projeke botho moo batho ba bangata ba kenya letsoho classifications. Empa, bakeng sa ba modumo e itseng ya data, boiteko bo hloekileng botho ba ke ke ba lekaneng. Ka nako eo, bafuputsi ba lokela ho haha ​​litsamaiso bobeli molokong o mong ka moo classifications botho li sebelisetsoa ho koetlisa mochine ithuta mohlala eo ka nako eo e sebelisoa ho bokae hoo e batlang e se nang moeli ya data.