論文紹介： "A Unified Search Federation System Based on Online User Feedback"

社内勉強会の発表スライドです。

Transcript

1. A Unified Search Federa/on System
   Based on Online User Feedback
   Authors: Luo Jie, Sudarshan Lamkhede, Rochit Sapra,
   Evans Hsu, Helen Song, Yi Chang (at Yahoo! Labs,
   Yahoo! Search, Yahoo! Taiwan)
   Proceedings of the 19th ACM SIGKDD interna:onal
   conference on Knowledge discovery and data mining
   - KDD '13
   ঺հऀ: দଜ Үੜ (CA ProFit-X)
   Journal Club, 2015-03-27 1
   

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2. ࿦จͷ֓؍
   • YahooͰݕࡧ݁Ռϖʔδͷ࠷దԽΛContextual
   BanditͰϞσϧԽ࣮ͯ͠૷͠ɼDaily਺ԯΫΤϦͷ
   ຊ൪؀ڥͰӡ༻ͨ͠ࣄྫ
   • ใुਪఆث(ઢܗϞσϧ)ͷֶशΛVowpal WabbitͰ
   ߦ͍ɼ਺ԯexamplesΛ਺෼Ͱॲཧ
   • ෳ਺ͷػցֶशͷࠞ੒Ͱ͋ͬͨچ൛γεςϜʹൺ
   ΂ͯɼCTR͕࠷େ200%ఔ޲্ͨ͠
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3. എܠɾѻ͏໰୊
   ౷߹ݕࡧʢδϟϯϧʹಛԽͨ͠
   ݕࡧαϒγεςϜΛ౷߹ͯ͠ද
   ࣔʣ
   ΫΤϦ͝ͱʹϢʔβͷڵຯ͋Δ
   δϟϯϧΛਪఆ͍͕ͨ͠ɼWeb
   ίϯςϯπ΋ΫΤϦ΋๲େͰ࣌
   ࣄࠁʑͱมԽ͢Δ
   े෼ͳϥϕϧ෇͖σʔλΛͲ͏
   ूΊΔଓ͚Δ͔ʁ
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4. ຊ࿦
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5. Contextual Bandit ͷ֓ཁ
   ֤࣌ࠁ ʹ͓͍ͯԼΛߦ͍ใुͷ࿨Λ࠷େԽ͢Δɿ
   1. ֤ΞΫγϣϯ ͷจ຺৘ใ͕ಛ௃ϕΫτϧ Ͱ
   ༩͑ΒΕΔ
   2. ֤ΞΫγϣϯ͝ͱʹใु Λਪఆ͢Δ
   3. ΞΫγϣϯ Λ1ͭબ୒ɾ࣮ߦ͠ใु ΛಘΔ
   4. ಘͨใुʹΑͬͯ 2. 3.ͷਪఆͱબ୒Λվળ͢Δ
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6. ౷߹ݕࡧΛContextual Banditͱͯ͠ϞσϧԽ
   ΞΫγϣϯɿ දࣔ͢Δδϟϯϧͷ૊ (Ґஔ΍಺༰ͷҧ
   ͍͸ࣺ৅ʣ
   ใुɿ δϟϯϧ͝ͱͷ click-skip஋ (ޙड़) ͷ߹ܭ
   ୳ࡧɿ Ұఆ֬཰ ( -greedy)ɼׂ౰Ґஔ΋ϥϯμϜ
   ׆༻ɿ ্͔Βॱʹਪఆใुͷߴ͍δϟϯϧΛׂ౰
   ૉੑɿ ݕࡧޠɼݕࡧ৔ॴɼδϟϯϧຖͷݕࡧ݁Ռ΍
   ώοτ਺ͳͲ
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7. ใु: δϟϯϧຖclick-skipͷ߹ܭ
   click-skipͰͷՃࢉ஋
   - ΫϦοΫ͞Εͨδϟϯϧ͸+1
   - ͦΕΑΓ্ͷδϟϯϧ͸-1
   - ͦΕΑΓԼͷδϟϯϧ͸+0
   Ϣʔβຬ଍౓ͷࢦඪ͸ଞʹ΋͋
   Δ͕...
   - CTR͸ԼҐදࣔͷ΋ͷ͕ෆར
   - ηογϣϯϨϕϧͷ΋ͷ2͸ߩ
   ݙ౓ͷׂ౰͕ෳࡶ
   2 PTS (path to success) ͳͲ
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8. γεςϜ֓ཁɿ ୳ࡧͰಘΒΕͨϩά͔Β܇࿅σʔλΛੜ੒͠ɼ
   ͦΕΛֶशͯ͠ಘΒΕͨϞσϧͰใुΛਪఆͯ͠׆༻͢Δ
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9. ౷ܭϞσϧͱֶशख๏
   ܇࿅σʔλͷ example ͸ ͷ4ͭ૊, ͸
   exampleͷॏཁ౓3ɽ
   จ຺ , ΞΫγϣϯ ͷظ଴ใु͸
   SGD, L-BFGSͰॏΈ Λਪఆɽ࣮૷͸VW4ɽ
   4 h$ps:/
   /github.com/JohnLangford/vowpal_wabbit
   3 ͦͷ഑ஔ͕ੜ͡Δ֬཰ ͷٯ਺ɽϏδωε্ͷ੍໿΍໢ཏੑʹґଘɽ4.1અʹৄࡉɽ
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10. USͰͷCTRͷมԽ
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11. ·ͱΊ
    • ౷߹ݕࡧΛContextual BanditͰϞσϧԽɾ࣮૷ɼ
    Daily਺ԯΫΤϦͷຊ൪؀ڥͰӡ༻
    • ใुਪఆث(ઢܗϞσϧ)ͷֶशΛVowpal WabbitͰ
    • ෳ਺ͷػցֶशͷࠞ੒Ͱ͋ͬͨچ൛γεςϜʹൺ
    ΂ͯɼCTR͕࠷େ200%ఔ޲্
    <঺հ͠ͳ͔ͬͨ಺༰>
    ΦϑϥΠϯςετɺ୆࿷ͰͷධՁ݁Ռ ͳͲ
    Journal Club, 2015-03-27 11
    

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