{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:M6TQFT6VD2D3QP2REBMBZLYC7N","short_pith_number":"pith:M6TQFT6V","canonical_record":{"source":{"id":"1603.02977","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ML","submitted_at":"2016-03-08T08:07:26Z","cross_cats_sorted":["stat.AP"],"title_canon_sha256":"ab085d3d2ad31743c3f2e74d8190fab1cc221bd78e73e6a9881e29606c31e23c","abstract_canon_sha256":"2515097c97d5f327b647412fcb545d269e7482a4a8ca001bc3f1f2786414baa5"},"schema_version":"1.0"},"canonical_sha256":"67a702cfd51e87b83f5120581caf02fb783eaaf14b2f824f0a704f60a56a06f9","source":{"kind":"arxiv","id":"1603.02977","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1603.02977","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"arxiv_version","alias_value":"1603.02977v1","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1603.02977","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"pith_short_12","alias_value":"M6TQFT6VD2D3","created_at":"2026-05-18T12:30:29Z"},{"alias_kind":"pith_short_16","alias_value":"M6TQFT6VD2D3QP2R","created_at":"2026-05-18T12:30:29Z"},{"alias_kind":"pith_short_8","alias_value":"M6TQFT6V","created_at":"2026-05-18T12:30:29Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:M6TQFT6VD2D3QP2REBMBZLYC7N","target":"record","payload":{"canonical_record":{"source":{"id":"1603.02977","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ML","submitted_at":"2016-03-08T08:07:26Z","cross_cats_sorted":["stat.AP"],"title_canon_sha256":"ab085d3d2ad31743c3f2e74d8190fab1cc221bd78e73e6a9881e29606c31e23c","abstract_canon_sha256":"2515097c97d5f327b647412fcb545d269e7482a4a8ca001bc3f1f2786414baa5"},"schema_version":"1.0"},"canonical_sha256":"67a702cfd51e87b83f5120581caf02fb783eaaf14b2f824f0a704f60a56a06f9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:19:19.419772Z","signature_b64":"CD7UEoLDx5qL9jH0c1hd5KBNdAH5fakb0ApUOUazZth0g/l7t9FviKb89yeBdGwHdOBiCNVuyw+VjBOz88OpBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"67a702cfd51e87b83f5120581caf02fb783eaaf14b2f824f0a704f60a56a06f9","last_reissued_at":"2026-05-18T01:19:19.419388Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:19:19.419388Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1603.02977","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":"2026-05-18T01:19:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"l5ELFAXEcKLaGQ3kXGFCubCVNykf6kwEJ/TjmriyYM4bH1arDYGfeiBVXd3/KZtqirRaxxcoPbK1X4MxYw64Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-11T06:04:51.631520Z"},"content_sha256":"b2c9422b53a4696b97204b5d5b2e8588fe70c741fd0c288951632a0efcbcdee8","schema_version":"1.0","event_id":"sha256:b2c9422b53a4696b97204b5d5b2e8588fe70c741fd0c288951632a0efcbcdee8"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:M6TQFT6VD2D3QP2REBMBZLYC7N","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Frequency estimation in three-phase power systems with harmonic contamination: A multistage quaternion Kalman filtering approach","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["stat.AP"],"primary_cat":"stat.ML","authors_text":"Danilo P. Mandic, Sayed Pouria Talebi","submitted_at":"2016-03-08T08:07:26Z","abstract_excerpt":"Motivated by the need for accurate frequency information, a novel algorithm for estimating the fundamental frequency and its rate of change in three-phase power systems is developed. This is achieved through two stages of Kalman filtering. In the first stage a quaternion extended Kalman filter, which provides a unified framework for joint modeling of voltage measurements from all the phases, is used to estimate the instantaneous phase increment of the three-phase voltages. The phase increment estimates are then used as observations of the extended Kalman filter in the second stage that account"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1603.02977","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":"2026-05-18T01:19:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"jPZApbJIK4rC5r10PBdNcTV0pR6iRuSMwclEQn689UuNKyqCifUVbwKwRjLBJsr1Dxx06xYfB3+oRC+LlLvsBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-11T06:04:51.632224Z"},"content_sha256":"deb863f0e0edd0d4c4d0a6f42fb59310d4457139428aa86c0e7adb40daeb8667","schema_version":"1.0","event_id":"sha256:deb863f0e0edd0d4c4d0a6f42fb59310d4457139428aa86c0e7adb40daeb8667"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/bundle.json","state_url":"https://pith.science/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/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":"2026-06-11T06:04:51Z","links":{"resolver":"https://pith.science/pith/M6TQFT6VD2D3QP2REBMBZLYC7N","bundle":"https://pith.science/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/bundle.json","state":"https://pith.science/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/state.json","well_known_bundle":"https://pith.science/.well-known/pith/M6TQFT6VD2D3QP2REBMBZLYC7N/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:M6TQFT6VD2D3QP2REBMBZLYC7N","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":"2515097c97d5f327b647412fcb545d269e7482a4a8ca001bc3f1f2786414baa5","cross_cats_sorted":["stat.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ML","submitted_at":"2016-03-08T08:07:26Z","title_canon_sha256":"ab085d3d2ad31743c3f2e74d8190fab1cc221bd78e73e6a9881e29606c31e23c"},"schema_version":"1.0","source":{"id":"1603.02977","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1603.02977","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"arxiv_version","alias_value":"1603.02977v1","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1603.02977","created_at":"2026-05-18T01:19:19Z"},{"alias_kind":"pith_short_12","alias_value":"M6TQFT6VD2D3","created_at":"2026-05-18T12:30:29Z"},{"alias_kind":"pith_short_16","alias_value":"M6TQFT6VD2D3QP2R","created_at":"2026-05-18T12:30:29Z"},{"alias_kind":"pith_short_8","alias_value":"M6TQFT6V","created_at":"2026-05-18T12:30:29Z"}],"graph_snapshots":[{"event_id":"sha256:deb863f0e0edd0d4c4d0a6f42fb59310d4457139428aa86c0e7adb40daeb8667","target":"graph","created_at":"2026-05-18T01:19:19Z","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":"Motivated by the need for accurate frequency information, a novel algorithm for estimating the fundamental frequency and its rate of change in three-phase power systems is developed. This is achieved through two stages of Kalman filtering. In the first stage a quaternion extended Kalman filter, which provides a unified framework for joint modeling of voltage measurements from all the phases, is used to estimate the instantaneous phase increment of the three-phase voltages. The phase increment estimates are then used as observations of the extended Kalman filter in the second stage that account","authors_text":"Danilo P. Mandic, Sayed Pouria Talebi","cross_cats":["stat.AP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ML","submitted_at":"2016-03-08T08:07:26Z","title":"Frequency estimation in three-phase power systems with harmonic contamination: A multistage quaternion Kalman filtering approach"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1603.02977","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:b2c9422b53a4696b97204b5d5b2e8588fe70c741fd0c288951632a0efcbcdee8","target":"record","created_at":"2026-05-18T01:19:19Z","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":"2515097c97d5f327b647412fcb545d269e7482a4a8ca001bc3f1f2786414baa5","cross_cats_sorted":["stat.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"stat.ML","submitted_at":"2016-03-08T08:07:26Z","title_canon_sha256":"ab085d3d2ad31743c3f2e74d8190fab1cc221bd78e73e6a9881e29606c31e23c"},"schema_version":"1.0","source":{"id":"1603.02977","kind":"arxiv","version":1}},"canonical_sha256":"67a702cfd51e87b83f5120581caf02fb783eaaf14b2f824f0a704f60a56a06f9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"67a702cfd51e87b83f5120581caf02fb783eaaf14b2f824f0a704f60a56a06f9","first_computed_at":"2026-05-18T01:19:19.419388Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:19:19.419388Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"CD7UEoLDx5qL9jH0c1hd5KBNdAH5fakb0ApUOUazZth0g/l7t9FviKb89yeBdGwHdOBiCNVuyw+VjBOz88OpBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:19:19.419772Z","signed_message":"canonical_sha256_bytes"},"source_id":"1603.02977","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b2c9422b53a4696b97204b5d5b2e8588fe70c741fd0c288951632a0efcbcdee8","sha256:deb863f0e0edd0d4c4d0a6f42fb59310d4457139428aa86c0e7adb40daeb8667"],"state_sha256":"052d81cd61a52d433d8af3b22cc25a2312c9d864a7f4ae80d03d3fee45b488c5"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"n17k4D2tKCHwQCtAAH5K70hZwa+V3vIOzTFUAyEKvEgIhDOPUQ1AY3VOG0AV2X0zMXDGg1HCJPNuZwhOOSzoBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-11T06:04:51.636225Z","bundle_sha256":"ecb87abc1eff7778cd541dab2aefbd58a3aa6d4847135cfca23d1e904536b8f1"}}