{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:EC4FKPLXVBP3OOR7M4ZXPKDNCP","short_pith_number":"pith:EC4FKPLX","canonical_record":{"source":{"id":"1809.06114","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2018-09-17T10:24:27Z","cross_cats_sorted":[],"title_canon_sha256":"21ab01aee87d58c8d1c5c377b7c67b437d464aa3e94eee2bb436122d94374129","abstract_canon_sha256":"7f9eff3580aa1ffab6e70839e056b77ce8220668d6fa89c6b1bea9805f27bce4"},"schema_version":"1.0"},"canonical_sha256":"20b8553d77a85fb73a3f673377a86d13ffdf9384d4f29f08da5d5b11c416905b","source":{"kind":"arxiv","id":"1809.06114","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1809.06114","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"arxiv_version","alias_value":"1809.06114v3","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1809.06114","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"pith_short_12","alias_value":"EC4FKPLXVBP3","created_at":"2026-05-18T12:32:22Z"},{"alias_kind":"pith_short_16","alias_value":"EC4FKPLXVBP3OOR7","created_at":"2026-05-18T12:32:22Z"},{"alias_kind":"pith_short_8","alias_value":"EC4FKPLX","created_at":"2026-05-18T12:32:22Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:EC4FKPLXVBP3OOR7M4ZXPKDNCP","target":"record","payload":{"canonical_record":{"source":{"id":"1809.06114","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2018-09-17T10:24:27Z","cross_cats_sorted":[],"title_canon_sha256":"21ab01aee87d58c8d1c5c377b7c67b437d464aa3e94eee2bb436122d94374129","abstract_canon_sha256":"7f9eff3580aa1ffab6e70839e056b77ce8220668d6fa89c6b1bea9805f27bce4"},"schema_version":"1.0"},"canonical_sha256":"20b8553d77a85fb73a3f673377a86d13ffdf9384d4f29f08da5d5b11c416905b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:53:50.791696Z","signature_b64":"1Wv6VPdVC4H9HKFGPuAfrMiTPY2hzW//Yzyed496B8U8Pwq/mP0/9INRTLlnZpzXqrVGJNDQxP4/dbtXDBILDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"20b8553d77a85fb73a3f673377a86d13ffdf9384d4f29f08da5d5b11c416905b","last_reissued_at":"2026-05-17T23:53:50.790907Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:53:50.790907Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1809.06114","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:53:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"l/IWfMyS9cZoHerq7dLaXily6sT3BTQRcMPC6dHOALPnSkeORLi4ZFkS/WYmvj7nqOIPKQB37y7+K8wRyBtaAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T10:32:11.894338Z"},"content_sha256":"db58bd2375cfbce91f827807e39d49cfe3cb3df1fd32a0db602d3a1062532774","schema_version":"1.0","event_id":"sha256:db58bd2375cfbce91f827807e39d49cfe3cb3df1fd32a0db602d3a1062532774"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:EC4FKPLXVBP3OOR7M4ZXPKDNCP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Constraint-consistent Runge-Kutta methods for one-dimensional incompressible multiphase flow","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.NA","authors_text":"Arthur E.P. Veldman, Benjamin Sanderse","submitted_at":"2018-09-17T10:24:27Z","abstract_excerpt":"New time integration methods are proposed for simulating incompressible multiphase flow in pipelines described by the one-dimensional two-fluid model. The methodology is based on 'half-explicit' Runge-Kutta methods, being explicit for the mass and momentum equations and implicit for the volume constraint. These half-explicit methods are constraint-consistent, i.e., they satisfy the hidden constraints of the two-fluid model, namely the volumetric flow (incompressibility) constraint and the Poisson equation for the pressure. A novel analysis shows that these hidden constraints are present in the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.06114","kind":"arxiv","version":3},"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":"2026-05-17T23:53:50Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GVUItRyD3R93yrJD2PyoF3c4Y/I5pXiPHbncMG79wXGxANqkvV7UW+vMN9jGG6LMBed4wWH5G0qSzoDHaUCoDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T10:32:11.894694Z"},"content_sha256":"3ce5f82a68449a0e627d6a718a1a405336191824f8105eb016e5de2aa7f4b847","schema_version":"1.0","event_id":"sha256:3ce5f82a68449a0e627d6a718a1a405336191824f8105eb016e5de2aa7f4b847"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/bundle.json","state_url":"https://pith.science/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/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":"2026-06-23T10:32:11Z","links":{"resolver":"https://pith.science/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP","bundle":"https://pith.science/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/bundle.json","state":"https://pith.science/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EC4FKPLXVBP3OOR7M4ZXPKDNCP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:EC4FKPLXVBP3OOR7M4ZXPKDNCP","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":"7f9eff3580aa1ffab6e70839e056b77ce8220668d6fa89c6b1bea9805f27bce4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2018-09-17T10:24:27Z","title_canon_sha256":"21ab01aee87d58c8d1c5c377b7c67b437d464aa3e94eee2bb436122d94374129"},"schema_version":"1.0","source":{"id":"1809.06114","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1809.06114","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"arxiv_version","alias_value":"1809.06114v3","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1809.06114","created_at":"2026-05-17T23:53:50Z"},{"alias_kind":"pith_short_12","alias_value":"EC4FKPLXVBP3","created_at":"2026-05-18T12:32:22Z"},{"alias_kind":"pith_short_16","alias_value":"EC4FKPLXVBP3OOR7","created_at":"2026-05-18T12:32:22Z"},{"alias_kind":"pith_short_8","alias_value":"EC4FKPLX","created_at":"2026-05-18T12:32:22Z"}],"graph_snapshots":[{"event_id":"sha256:3ce5f82a68449a0e627d6a718a1a405336191824f8105eb016e5de2aa7f4b847","target":"graph","created_at":"2026-05-17T23:53:50Z","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":"New time integration methods are proposed for simulating incompressible multiphase flow in pipelines described by the one-dimensional two-fluid model. The methodology is based on 'half-explicit' Runge-Kutta methods, being explicit for the mass and momentum equations and implicit for the volume constraint. These half-explicit methods are constraint-consistent, i.e., they satisfy the hidden constraints of the two-fluid model, namely the volumetric flow (incompressibility) constraint and the Poisson equation for the pressure. A novel analysis shows that these hidden constraints are present in the","authors_text":"Arthur E.P. Veldman, Benjamin Sanderse","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2018-09-17T10:24:27Z","title":"Constraint-consistent Runge-Kutta methods for one-dimensional incompressible multiphase flow"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1809.06114","kind":"arxiv","version":3},"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:db58bd2375cfbce91f827807e39d49cfe3cb3df1fd32a0db602d3a1062532774","target":"record","created_at":"2026-05-17T23:53:50Z","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":"7f9eff3580aa1ffab6e70839e056b77ce8220668d6fa89c6b1bea9805f27bce4","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.NA","submitted_at":"2018-09-17T10:24:27Z","title_canon_sha256":"21ab01aee87d58c8d1c5c377b7c67b437d464aa3e94eee2bb436122d94374129"},"schema_version":"1.0","source":{"id":"1809.06114","kind":"arxiv","version":3}},"canonical_sha256":"20b8553d77a85fb73a3f673377a86d13ffdf9384d4f29f08da5d5b11c416905b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"20b8553d77a85fb73a3f673377a86d13ffdf9384d4f29f08da5d5b11c416905b","first_computed_at":"2026-05-17T23:53:50.790907Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:53:50.790907Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"1Wv6VPdVC4H9HKFGPuAfrMiTPY2hzW//Yzyed496B8U8Pwq/mP0/9INRTLlnZpzXqrVGJNDQxP4/dbtXDBILDw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:53:50.791696Z","signed_message":"canonical_sha256_bytes"},"source_id":"1809.06114","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:db58bd2375cfbce91f827807e39d49cfe3cb3df1fd32a0db602d3a1062532774","sha256:3ce5f82a68449a0e627d6a718a1a405336191824f8105eb016e5de2aa7f4b847"],"state_sha256":"b522216d7828482b0b651a2188891669a7fd1f4c08ed90d00b6c85706bce5707"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CJzFnuY41UYp3PSITLKvHj2SVv96EXrSv9SdhurAaqnBuQQmcIxy7W35+9+gJlvSXqQkpJNoDPQjam6cXhmzBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-23T10:32:11.896658Z","bundle_sha256":"7331de908a4753b1bc8ac2f3677f9f45fa762985c2eb5133b0920e0140cb7a74"}}