{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:YDBDDAFTQQWLHHLRGOBFJSHBH4","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":"979cd1bb14f49d8b8088d7f240ac1340d23eed75aaf1c2acde7efcc1b06f1afb","cross_cats_sorted":["stat.ML"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.LG","submitted_at":"2018-03-12T23:27:06Z","title_canon_sha256":"a1611269824b786dc41d4b2af461aa4ae7085c63caa8f2bdb48d8d7daf9cded8"},"schema_version":"1.0","source":{"id":"1803.04572","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1803.04572","created_at":"2026-05-18T00:07:10Z"},{"alias_kind":"arxiv_version","alias_value":"1803.04572v2","created_at":"2026-05-18T00:07:10Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1803.04572","created_at":"2026-05-18T00:07:10Z"},{"alias_kind":"pith_short_12","alias_value":"YDBDDAFTQQWL","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_16","alias_value":"YDBDDAFTQQWLHHLR","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_8","alias_value":"YDBDDAFT","created_at":"2026-05-18T12:33:04Z"}],"graph_snapshots":[{"event_id":"sha256:7d8087cfc9290a6feeb198f693e734660198737bf644c5185d3900c9017897ab","target":"graph","created_at":"2026-05-18T00:07:10Z","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":"PARAFAC2 has demonstrated success in modeling irregular tensors, where the tensor dimensions vary across one of the modes. An example scenario is modeling treatments across a set of patients with the varying number of medical encounters over time. Despite recent improvements on unconstrained PARAFAC2, its model factors are usually dense and sensitive to noise which limits their interpretability. As a result, the following open challenges remain: a) various modeling constraints, such as temporal smoothness, sparsity and non-negativity, are needed to be imposed for interpretable temporal modelin","authors_text":"Ardavan Afshar, Elizabeth Searles, Evangelos E. Papalexakis, Ioakeim Perros, Jimeng Sun, Joyce Ho","cross_cats":["stat.ML"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.LG","submitted_at":"2018-03-12T23:27:06Z","title":"COPA: Constrained PARAFAC2 for Sparse & Large Datasets"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1803.04572","kind":"arxiv","version":2},"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":"sha256:1768087da1cb0b7f7ea167d4644503347d20916ca8e455409125f93cc7411ca2","target":"record","created_at":"2026-05-18T00:07:10Z","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":"979cd1bb14f49d8b8088d7f240ac1340d23eed75aaf1c2acde7efcc1b06f1afb","cross_cats_sorted":["stat.ML"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.LG","submitted_at":"2018-03-12T23:27:06Z","title_canon_sha256":"a1611269824b786dc41d4b2af461aa4ae7085c63caa8f2bdb48d8d7daf9cded8"},"schema_version":"1.0","source":{"id":"1803.04572","kind":"arxiv","version":2}},"canonical_sha256":"c0c23180b3842cb39d71338254c8e13f1f2d138b8bf93a6f27a01221e2be3711","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c0c23180b3842cb39d71338254c8e13f1f2d138b8bf93a6f27a01221e2be3711","first_computed_at":"2026-05-18T00:07:10.433342Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:07:10.433342Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"j5TnVAOUZbj//OH5glYj/xPCjbLetqyU0Pr0BWqJUNO/bLoBtWIWlppGghkZHbXrQKvqfhgTyVu4Sj2cgbQqBg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:07:10.433945Z","signed_message":"canonical_sha256_bytes"},"source_id":"1803.04572","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1768087da1cb0b7f7ea167d4644503347d20916ca8e455409125f93cc7411ca2","sha256:7d8087cfc9290a6feeb198f693e734660198737bf644c5185d3900c9017897ab"],"state_sha256":"173b690b880f19f9dbb4538a586c126cc80346ef6d1c19c96d8f1a8e672cf1b0"}