Binciken bangaren jagora

Binciken bangaren kai tsaye (DCA) wata hanya ce ta ƙididdiga da aka yi amfani da ita a cikin ilimin kimiyyar yanayi don gano alamun wakilci na sauye-sauye a cikin bayanan lokaci-lokaci kamar abubuwan lura da yanayin yanayi na tarihi,Jewson, S. (2020). "An Alternative to PCA for Estimating Dominant Patterns of Climate Variability and Extremes, with Application to U.S. and China Seasonal Rainfall". Atmosphere. 11 (4): 354. Bibcode:2020Atmos..11..354J. doi:10.3390/atmos11040354. hasashen yanayi ensembles ko yanayin yanayi.Jewson, S.; Messori, G.; Barbato, G.; Mercogliano, P.; Mysiak, J.; Sassi, M. (2022). "Developing Representative Impact Scenarios From Climate Projection Ensembles, With Application to UKCP18 and EURO-CORDEX Precipitation". Journal of Advances in Modeling Earth Systems. 15 (1). doi:10.1029/2022MS003038. S2CID 254965361.

Tsarin DCA na farko shi ne yanayin yanayi ko canjin yanayi wanda duka biyun zasu iya faruwa (aunawa ta amfani da yuwuwar) kuma yana da babban tasiri (don ƙayyadaddun tasirin tasiri na layi, kuma an ba da wasu yanayi na lissafi: duba ƙasa).Scher, S.; Jewson, S.; Messori, G. (2021). "Robust Worst-Case Scenarios from Ensemble Forecasts". Weather and Forecasting. 36 (4): 1357–1373. Bibcode:2021WtFor..36.1357S. doi:10.1175/WAF-D-20-0219.1. S2CID 236300040.

Tsarin DCA na farko ya bambanta da tsarin PCA na farko, wanda zai yiwu ya faru, amma maiyuwa bazai sami babban tasiri ba, kuma tare da tsarin da aka samo daga gradient na aikin tasiri, wanda ke da babban tasiri, amma mai yiwuwa ba zai iya faruwa ba.

DCA ya bambanta da sauran hanyoyin gano alamu da aka yi amfani da su a cikin binciken yanayi, irin su EOFs, juya EOFs da kuma EOFs mai tsawo a cikin cewa yana la'akari da vector na waje, girman tasirin tasirin.Mestas-Nunez, A. (2000). "Orthogonality properties of rotated empirical modes". International Journal of Climatology. 20 (12): 1509–1516. doi:10.1002/1097-0088(200010)20:12<1509::AID-JOC553>3.0.CO;2-Q

DCA tana ba da hanya don rage manyan taruka daga hasashen yanayi ko ƙirar yanayi zuwa alamu biyu kawai. Tsarin farko shine ma'anar haɗuwa, kuma tsari na biyu shine tsarin DCA, wanda ke wakiltar sauye-sauye a kusa da ma'anar ma'anar ta hanyar da za ta yi tasiri a cikin lissafi. DCA ya bambanta da sauran hanyoyin da aka ba da shawarar don rage ƙungiyoyin l a cikin cewa yana ɗaukar tasiri a cikin la'akari da tsarin tsarin.

 Dubawa 

 Abubuwan shigarwa 
Ana ƙididdige DCA daga abubuwa biyu:

saitin bayanai iri-iri na yanayi ko bayanan yanayi, kamar abubuwan lura da yanayi na tarihi, ko yanayin yanayi ko taron yanayi.

aikin tasiri na linzamin kwamfuta. Ayyukan tasiri na linzamin aiki aiki ne wanda ke bayyana matakin tasiri ga kowane yanayin sararin samaniya a cikin yanayi ko bayanan yanayi a matsayin jimlar ma'auni na ma'auni a wurare daban-daban a cikin yanayin sararin samaniya. Misali shine maƙasudin ƙima a cikin tsarin sararin samaniya. Za a iya samar da aikin tasiri na layi a matsayin kalma ta farko a cikin jerin nau'in Taylor mai yawa na aikin tasirin da ba na layi ba.Mestas-Nunez, A. (2000). "Orthogonality properties of rotated empirical modes". International Journal of Climatology. 20 (12): 1509–1516. doi:10.1002/1097-0088(200010)20:12<1509::AID-JOC553>3.0.CO;2-Q

 Formula 
Yi la'akari da saitin bayanan lokacin sarari

X

{\displaystyle X}, yana ƙunshe da nau'ikan ƙirar sararin samaniya

x

{\ displaystyle x}, inda ake ɗaukar kowane tsarin kowane ɗayan a matsayin samfura guda ɗaya daga rarraba al'ada mai yawa tare da ma'anar sifili da matrix covariance.

C

{\nuni C}.

Muna ayyana aikin tasiri na linzamin kwamfuta na tsarin sararin samaniya kamar

r

t

x

{\displaystyle r^{t}x}, ina

r

{\displaystyle r} shine ma'aunin nauyi na sarari.

An ba da tsarin DCA na farko cikin sharuddan matrix covariance

C

{\displaystyle C} da ma'auni

r

{\displaystyle r} ta madaidaicin magana

x

∝

C

r

{\displaystyle x\propto Cr}.

Ana iya daidaita tsarin zuwa kowane tsayi kamar yadda ake buƙata.

Kayayyaki

Idan an rarraba bayanan yanayi ko yanayin yanayi (misali, an rarraba shi azaman rarrabawar al'ada mai yawa ko rarraba t-rabawa mai yawa) to ana bayyana tsarin DCA na farko (DCA1) azaman yanayin sararin samaniya tare da abubuwan lissafi masu zuwa:

DCA1 yana ƙara girman yuwuwar yuwuwar ga ƙimar da aka bayar na tasiri

DCA1 yana haɓaka tasiri don ƙimar yuwuwar yuwuwar

DCA1 yana haɓaka samfurin tasiri da yuwuwar yuwuwar

DCA1 shine tsammanin sharadi, sharadi akan wuce wani matakin tasiri

DCA1 shine ma'anar tasiri mai nauyin nauyi

Duk wani gyare-gyare na DCA1 zai haifar da wani tsari wanda ko dai ya wuce iyaka, ko kuma yana da ƙananan yuwuwar yuwuwar.

Misalin ruwan sama

Misali, a cikin ma'auni na rashin daidaituwa na ruwan sama, ta amfani da ma'aunin tasirin da aka ayyana a matsayin jimlar ruwan sama, tsarin DCA na farko shine tsarin sararin samaniya wanda ke da mafi girman yuwuwar yuwuwar yawan ruwan sama da aka bayar. Idan an zaɓi yawan ruwan sama da aka ba da shi don samun babban darajar, to wannan tsarin ya haɗu da kasancewa matsananci dangane da ma'auni (watau, wakiltar yawan yawan ruwan sama) tare da kasancewa mai yiwuwa dangane da tsarin, don haka ya dace sosai a matsayin wakilin matsananciyar tsari.

Kwatanta da PCA

Babban bambance-bambancen da ke tsakanin Babban Fassara (PCA) da DCA sune

PCA aiki ne na matrix covariance kawai, kuma ana siffanta tsarin PCA na farko don haɓaka bambance-bambancen da aka bayyana.

DCA aiki ne na matrix covariance da kuma jagorar vector (ƙarfin aikin tasiri), kuma ana siffanta tsarin DCA na farko don ƙara girman yuwuwar yuwuwar ƙimar ƙimar tasirin tasirin.

Sakamakon haka, don ƙirar sararin samaniya na naúrar:

Tsarin sararin samaniya na farko na PCA koyaushe yana dacewa da bambance-bambancen da aka bayyana mafi girma, amma yana da ƙarancin ƙimar ma'aunin tasiri (misali, jimlar ruwan sama), sai dai a cikin yanayin lalacewa.

Tsarin sararin samaniya na DCA na farko koyaushe yana dacewa da ƙimar mafi girma na ma'aunin tasiri, amma yana da ƙarancin ƙimar bambance-bambancen da aka bayyana, sai dai a lokuta masu lalacewa.

Matsalolin lalacewa suna faruwa lokacin da tsarin PCA da DCA suka yi daidai.

 Manazarta