{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:27FUB4ST56COGD27A3M5WV3MVL","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":"b6e99972e455d640a4f5388323c605af650fe681b24f82371513e66e4d05eb92","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2013-06-23T08:10:40Z","title_canon_sha256":"ba552e7d0b09ec777d4ba8a164e0d36f89ab64aa75a287fa6d03371cd24e5780"},"schema_version":"1.0","source":{"id":"1306.5386","kind":"arxiv","version":6}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1306.5386","created_at":"2026-05-18T02:29:39Z"},{"alias_kind":"arxiv_version","alias_value":"1306.5386v6","created_at":"2026-05-18T02:29:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1306.5386","created_at":"2026-05-18T02:29:39Z"},{"alias_kind":"pith_short_12","alias_value":"27FUB4ST56CO","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_16","alias_value":"27FUB4ST56COGD27","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_8","alias_value":"27FUB4ST","created_at":"2026-05-18T12:27:30Z"}],"graph_snapshots":[{"event_id":"sha256:7728c6d42101ec6010f023d4bd9ba9433419acad658a7104e3f6a08dea47ef42","target":"graph","created_at":"2026-05-18T02:29:39Z","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 a robust second-order method is developed for the solution of strongly convex l1-regularized problems. The main aim is to make the proposed method as inexpensive as possible, while even difficult problems can be efficiently solved. The proposed approach is a primal-dual Newton Conjugate Gradients (pdNCG) method. Convergence properties of pdNCG are studied and worst-case iteration complexity is established. Numerical results are presented on synthetic sparse least-squares problems and real world machine learning problems.","authors_text":"Jacek Gondzio, Kimon Fountoulakis","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2013-06-23T08:10:40Z","title":"A Second-Order Method for Strongly Convex L1-Regularization Problems"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1306.5386","kind":"arxiv","version":6},"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:cae5a2a346ff9e416a47319fa6bfbd0e3bc11f7fd60b8e4a1423986508218e0d","target":"record","created_at":"2026-05-18T02:29:39Z","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":"b6e99972e455d640a4f5388323c605af650fe681b24f82371513e66e4d05eb92","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2013-06-23T08:10:40Z","title_canon_sha256":"ba552e7d0b09ec777d4ba8a164e0d36f89ab64aa75a287fa6d03371cd24e5780"},"schema_version":"1.0","source":{"id":"1306.5386","kind":"arxiv","version":6}},"canonical_sha256":"d7cb40f253ef84e30f5f06d9db576caaca37bd93f3548ef83af3aebe80647c52","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d7cb40f253ef84e30f5f06d9db576caaca37bd93f3548ef83af3aebe80647c52","first_computed_at":"2026-05-18T02:29:39.274425Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:29:39.274425Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xLwP96/A9BWCEUCaIXo0nI9kcANvAOpCuaX0gIw20XixB51gg8HRpZ1+Yy33X6oPVcLOFriJo/Mus7DHkqEMAw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:29:39.274831Z","signed_message":"canonical_sha256_bytes"},"source_id":"1306.5386","source_kind":"arxiv","source_version":6}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:cae5a2a346ff9e416a47319fa6bfbd0e3bc11f7fd60b8e4a1423986508218e0d","sha256:7728c6d42101ec6010f023d4bd9ba9433419acad658a7104e3f6a08dea47ef42"],"state_sha256":"fd69a817befdc36bfe346f810fddebff948f4e574e29064b664f577c6fca042d"}