{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2010:3NYE4SPRB26GB7Y5A4MZSMYCY4","short_pith_number":"pith:3NYE4SPR","canonical_record":{"source":{"id":"1010.3988","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2010-10-19T17:32:26Z","cross_cats_sorted":["physics.soc-ph"],"title_canon_sha256":"5a6be087ccd0161d6945526153989aa169fba0737495d2382268d402908f8f2e","abstract_canon_sha256":"dfaa197ffacf04848a90cfced3a5e0995ac08590010623bbe11b4320d313344a"},"schema_version":"1.0"},"canonical_sha256":"db704e49f10ebc60ff1d0719993302c70fe0c40958bc4372c76ba6f2c5c9a3ed","source":{"kind":"arxiv","id":"1010.3988","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1010.3988","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"arxiv_version","alias_value":"1010.3988v1","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1010.3988","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"pith_short_12","alias_value":"3NYE4SPRB26G","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"3NYE4SPRB26GB7Y5","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"3NYE4SPR","created_at":"2026-05-18T12:26:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2010:3NYE4SPRB26GB7Y5A4MZSMYCY4","target":"record","payload":{"canonical_record":{"source":{"id":"1010.3988","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2010-10-19T17:32:26Z","cross_cats_sorted":["physics.soc-ph"],"title_canon_sha256":"5a6be087ccd0161d6945526153989aa169fba0737495d2382268d402908f8f2e","abstract_canon_sha256":"dfaa197ffacf04848a90cfced3a5e0995ac08590010623bbe11b4320d313344a"},"schema_version":"1.0"},"canonical_sha256":"db704e49f10ebc60ff1d0719993302c70fe0c40958bc4372c76ba6f2c5c9a3ed","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:39:07.099918Z","signature_b64":"kYNyivG/qvOiODm3WzXwWiHYuKnbu4K4QcAgRcEEY8o+J7ozkGbCAJYIgFkwFBwYATPsYGJ95krJAuGJ4dxQDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"db704e49f10ebc60ff1d0719993302c70fe0c40958bc4372c76ba6f2c5c9a3ed","last_reissued_at":"2026-05-18T04:39:07.099341Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:39:07.099341Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1010.3988","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T04:39:07Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1cY3PvPSeLPZM2Vy1VSfVgNPNkSP1AgfDg/QNfMl+ZZcf6CT3A5XY+n8tG5+uxFk3tGSiklbMMlQiJFUe6R6Bg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-25T12:40:00.444565Z"},"content_sha256":"68b9e4c6cf29c76630c06511fa78b3f6b776804c1ff38cf8acce240ff6f9bd1e","schema_version":"1.0","event_id":"sha256:68b9e4c6cf29c76630c06511fa78b3f6b776804c1ff38cf8acce240ff6f9bd1e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2010:3NYE4SPRB26GB7Y5A4MZSMYCY4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Time-aware Collaborative Filtering with the Piecewise Decay Function","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.soc-ph"],"primary_cat":"cs.IR","authors_text":"Chi Ho Yeung, Cihang Jin, Pei Wu, Weiping Liu, Yi-Cheng Zhang","submitted_at":"2010-10-19T17:32:26Z","abstract_excerpt":"In this paper, we determine the appropriate decay function for item-based collaborative filtering (CF). Instead of intuitive deduction, we introduce the Similarity-Signal-to-Noise-Ratio (SSNR) to quantify the impacts of rated items on current recommendations. By measuring the variation of SSNR over time, drift in user interest is well visualized and quantified. Based on the trend changes of SSNR, the piecewise decay function is thus devised and incorporated to build our time-aware CF algorithm. Experiments show that the proposed algorithm strongly outperforms the conventional item-based CF alg"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1010.3988","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T04:39:07Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2/FAHqPbYzI2l4d5I7fC2RswLzy4vEtU9GGCV7GspMER9sr5ctbWTAg/+dxM/Jab3sNpqhwi8Vlyg4r3AoQpDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-25T12:40:00.444895Z"},"content_sha256":"13ad69532332b65d29bc0c3897b1651f189724ca615b38dfa38c6090388d2e48","schema_version":"1.0","event_id":"sha256:13ad69532332b65d29bc0c3897b1651f189724ca615b38dfa38c6090388d2e48"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/bundle.json","state_url":"https://pith.science/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-25T12:40:00Z","links":{"resolver":"https://pith.science/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4","bundle":"https://pith.science/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/bundle.json","state":"https://pith.science/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3NYE4SPRB26GB7Y5A4MZSMYCY4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2010:3NYE4SPRB26GB7Y5A4MZSMYCY4","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"dfaa197ffacf04848a90cfced3a5e0995ac08590010623bbe11b4320d313344a","cross_cats_sorted":["physics.soc-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2010-10-19T17:32:26Z","title_canon_sha256":"5a6be087ccd0161d6945526153989aa169fba0737495d2382268d402908f8f2e"},"schema_version":"1.0","source":{"id":"1010.3988","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1010.3988","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"arxiv_version","alias_value":"1010.3988v1","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1010.3988","created_at":"2026-05-18T04:39:07Z"},{"alias_kind":"pith_short_12","alias_value":"3NYE4SPRB26G","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"3NYE4SPRB26GB7Y5","created_at":"2026-05-18T12:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"3NYE4SPR","created_at":"2026-05-18T12:26:03Z"}],"graph_snapshots":[{"event_id":"sha256:13ad69532332b65d29bc0c3897b1651f189724ca615b38dfa38c6090388d2e48","target":"graph","created_at":"2026-05-18T04:39:07Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"In this paper, we determine the appropriate decay function for item-based collaborative filtering (CF). Instead of intuitive deduction, we introduce the Similarity-Signal-to-Noise-Ratio (SSNR) to quantify the impacts of rated items on current recommendations. By measuring the variation of SSNR over time, drift in user interest is well visualized and quantified. Based on the trend changes of SSNR, the piecewise decay function is thus devised and incorporated to build our time-aware CF algorithm. Experiments show that the proposed algorithm strongly outperforms the conventional item-based CF alg","authors_text":"Chi Ho Yeung, Cihang Jin, Pei Wu, Weiping Liu, Yi-Cheng Zhang","cross_cats":["physics.soc-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2010-10-19T17:32:26Z","title":"Time-aware Collaborative Filtering with the Piecewise Decay Function"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1010.3988","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:68b9e4c6cf29c76630c06511fa78b3f6b776804c1ff38cf8acce240ff6f9bd1e","target":"record","created_at":"2026-05-18T04:39:07Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"dfaa197ffacf04848a90cfced3a5e0995ac08590010623bbe11b4320d313344a","cross_cats_sorted":["physics.soc-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IR","submitted_at":"2010-10-19T17:32:26Z","title_canon_sha256":"5a6be087ccd0161d6945526153989aa169fba0737495d2382268d402908f8f2e"},"schema_version":"1.0","source":{"id":"1010.3988","kind":"arxiv","version":1}},"canonical_sha256":"db704e49f10ebc60ff1d0719993302c70fe0c40958bc4372c76ba6f2c5c9a3ed","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"db704e49f10ebc60ff1d0719993302c70fe0c40958bc4372c76ba6f2c5c9a3ed","first_computed_at":"2026-05-18T04:39:07.099341Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:39:07.099341Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"kYNyivG/qvOiODm3WzXwWiHYuKnbu4K4QcAgRcEEY8o+J7ozkGbCAJYIgFkwFBwYATPsYGJ95krJAuGJ4dxQDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T04:39:07.099918Z","signed_message":"canonical_sha256_bytes"},"source_id":"1010.3988","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:68b9e4c6cf29c76630c06511fa78b3f6b776804c1ff38cf8acce240ff6f9bd1e","sha256:13ad69532332b65d29bc0c3897b1651f189724ca615b38dfa38c6090388d2e48"],"state_sha256":"82be55c8141a16cee20262d9d3baa0d4778e01bc369e7ce1d71612faaf74f865"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AO/mBo8kWXHI1r2pb14Ac2V+3cUn7QgnlQJGHjyKTXvv+toCv5AFEx0ZjQ3K25aFFfCW1weT/A6+aznkHEEIAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-25T12:40:00.446792Z","bundle_sha256":"49695b1df27a6e288879fed305a08a9a53115084a435c5c8e986f4cd2f2bc4c6"}}