{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:VOERQFRE2MS2SDE2C5XJEGJ2G4","short_pith_number":"pith:VOERQFRE","canonical_record":{"source":{"id":"1502.00199","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2015-02-01T04:56:13Z","cross_cats_sorted":[],"title_canon_sha256":"d755a109a0405483a5d2b5e761bdf851613619179b1d613926fe9fd34c0fe9c6","abstract_canon_sha256":"551b7b8108780cff9a2b180a0ff2cf2369e3c278dcdf27c778f53604b7db0522"},"schema_version":"1.0"},"canonical_sha256":"ab89181624d325a90c9a176e92193a3737363e8f17917c6d57d6df303828107f","source":{"kind":"arxiv","id":"1502.00199","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1502.00199","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"arxiv_version","alias_value":"1502.00199v1","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1502.00199","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"pith_short_12","alias_value":"VOERQFRE2MS2","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_16","alias_value":"VOERQFRE2MS2SDE2","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_8","alias_value":"VOERQFRE","created_at":"2026-05-18T12:29:47Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:VOERQFRE2MS2SDE2C5XJEGJ2G4","target":"record","payload":{"canonical_record":{"source":{"id":"1502.00199","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2015-02-01T04:56:13Z","cross_cats_sorted":[],"title_canon_sha256":"d755a109a0405483a5d2b5e761bdf851613619179b1d613926fe9fd34c0fe9c6","abstract_canon_sha256":"551b7b8108780cff9a2b180a0ff2cf2369e3c278dcdf27c778f53604b7db0522"},"schema_version":"1.0"},"canonical_sha256":"ab89181624d325a90c9a176e92193a3737363e8f17917c6d57d6df303828107f","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:28:06.469253Z","signature_b64":"lJq5jyzjGR2NUlyArWAovchz6jHq+2HDsXpbLIiWgnjJ2P2ugkDcD96pvA+PMNsqE4oE1N5MTRllqRZHzs48DQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ab89181624d325a90c9a176e92193a3737363e8f17917c6d57d6df303828107f","last_reissued_at":"2026-05-18T02:28:06.468925Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:28:06.468925Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1502.00199","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":"2026-05-18T02:28:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uGGbXnhVgC5KgjGrAWynQBz17J+bLWAbiz1FZhv0YRu2o35dnMGdCpRHq7lBcI9ISjPz/RBZCUkNPsp0UTYQCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T08:49:53.252077Z"},"content_sha256":"5fb77711b9d34174a159ce9e99816eb7407f83bb85491af83970b710ef52175d","schema_version":"1.0","event_id":"sha256:5fb77711b9d34174a159ce9e99816eb7407f83bb85491af83970b710ef52175d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:VOERQFRE2MS2SDE2C5XJEGJ2G4","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Chemical Reaction Optimization for the Set Covering Problem","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.NE","authors_text":"Albert Y.S. Lam, James J.Q. Yu, Victor O.K. Li","submitted_at":"2015-02-01T04:56:13Z","abstract_excerpt":"The set covering problem (SCP) is one of the representative combinatorial optimization problems, having many practical applications. This paper investigates the development of an algorithm to solve SCP by employing chemical reaction optimization (CRO), a general-purpose metaheuristic. It is tested on a wide range of benchmark instances of SCP. The simulation results indicate that this algorithm gives outstanding performance compared with other heuristics and metaheuristics in solving SCP."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.00199","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":"2026-05-18T02:28:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LjLVMeeeiGS31NBoFt8jzZA9LitFCQ43og64bxoCWtd8Q4soVt5kY5zD9ms1HixC2ZtDCm85h/6qpiXwtEN8Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T08:49:53.252436Z"},"content_sha256":"1c4331c83a5d275dbab223a3d471fde92c2350cd518817c07fabaa6b56b9d432","schema_version":"1.0","event_id":"sha256:1c4331c83a5d275dbab223a3d471fde92c2350cd518817c07fabaa6b56b9d432"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/bundle.json","state_url":"https://pith.science/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/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":"2026-06-02T08:49:53Z","links":{"resolver":"https://pith.science/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4","bundle":"https://pith.science/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/bundle.json","state":"https://pith.science/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VOERQFRE2MS2SDE2C5XJEGJ2G4/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:VOERQFRE2MS2SDE2C5XJEGJ2G4","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":"551b7b8108780cff9a2b180a0ff2cf2369e3c278dcdf27c778f53604b7db0522","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2015-02-01T04:56:13Z","title_canon_sha256":"d755a109a0405483a5d2b5e761bdf851613619179b1d613926fe9fd34c0fe9c6"},"schema_version":"1.0","source":{"id":"1502.00199","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1502.00199","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"arxiv_version","alias_value":"1502.00199v1","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1502.00199","created_at":"2026-05-18T02:28:06Z"},{"alias_kind":"pith_short_12","alias_value":"VOERQFRE2MS2","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_16","alias_value":"VOERQFRE2MS2SDE2","created_at":"2026-05-18T12:29:47Z"},{"alias_kind":"pith_short_8","alias_value":"VOERQFRE","created_at":"2026-05-18T12:29:47Z"}],"graph_snapshots":[{"event_id":"sha256:1c4331c83a5d275dbab223a3d471fde92c2350cd518817c07fabaa6b56b9d432","target":"graph","created_at":"2026-05-18T02:28:06Z","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":"The set covering problem (SCP) is one of the representative combinatorial optimization problems, having many practical applications. This paper investigates the development of an algorithm to solve SCP by employing chemical reaction optimization (CRO), a general-purpose metaheuristic. It is tested on a wide range of benchmark instances of SCP. The simulation results indicate that this algorithm gives outstanding performance compared with other heuristics and metaheuristics in solving SCP.","authors_text":"Albert Y.S. Lam, James J.Q. Yu, Victor O.K. Li","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2015-02-01T04:56:13Z","title":"Chemical Reaction Optimization for the Set Covering Problem"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.00199","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":"sha256:5fb77711b9d34174a159ce9e99816eb7407f83bb85491af83970b710ef52175d","target":"record","created_at":"2026-05-18T02:28:06Z","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":"551b7b8108780cff9a2b180a0ff2cf2369e3c278dcdf27c778f53604b7db0522","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.NE","submitted_at":"2015-02-01T04:56:13Z","title_canon_sha256":"d755a109a0405483a5d2b5e761bdf851613619179b1d613926fe9fd34c0fe9c6"},"schema_version":"1.0","source":{"id":"1502.00199","kind":"arxiv","version":1}},"canonical_sha256":"ab89181624d325a90c9a176e92193a3737363e8f17917c6d57d6df303828107f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ab89181624d325a90c9a176e92193a3737363e8f17917c6d57d6df303828107f","first_computed_at":"2026-05-18T02:28:06.468925Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:28:06.468925Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lJq5jyzjGR2NUlyArWAovchz6jHq+2HDsXpbLIiWgnjJ2P2ugkDcD96pvA+PMNsqE4oE1N5MTRllqRZHzs48DQ==","signature_status":"signed_v1","signed_at":"2026-05-18T02:28:06.469253Z","signed_message":"canonical_sha256_bytes"},"source_id":"1502.00199","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5fb77711b9d34174a159ce9e99816eb7407f83bb85491af83970b710ef52175d","sha256:1c4331c83a5d275dbab223a3d471fde92c2350cd518817c07fabaa6b56b9d432"],"state_sha256":"3346726dd40bc074684cea515c687d3e64c95000ca1a4c6cb55ad48dbf5b4455"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JR19sGcnvm0y2WhSCVM/WAWt1ozrGzdCj0qU8hD19Kw8B5g8XG++Va54IFkE76vz7e2ls095u2puuCMWupbvDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-02T08:49:53.254368Z","bundle_sha256":"c27801cb4a0af2aa91d0ccd4622a31ba14674c6d4274096c61359579dd8b52f3"}}