{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2014:W5NEKPJRYHPN52JOVTY5XRZL6M","short_pith_number":"pith:W5NEKPJR","canonical_record":{"source":{"id":"1405.6945","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2014-05-25T22:22:04Z","cross_cats_sorted":[],"title_canon_sha256":"c7fbbd4b9a708f3fa9f51a34a4c3e2cabf71b70e57481a5001ff5257fc168c1e","abstract_canon_sha256":"e3fd016e0527b11f5cd89aa8fa88c7f424e251a5e56f6ab0a8a7253922e8fb3f"},"schema_version":"1.0"},"canonical_sha256":"b75a453d31c1dedee92eacf1dbc72bf3010339b6b5918688a395a1e81ca3c3ed","source":{"kind":"arxiv","id":"1405.6945","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.6945","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"arxiv_version","alias_value":"1405.6945v1","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.6945","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"pith_short_12","alias_value":"W5NEKPJRYHPN","created_at":"2026-05-18T12:28:54Z"},{"alias_kind":"pith_short_16","alias_value":"W5NEKPJRYHPN52JO","created_at":"2026-05-18T12:28:54Z"},{"alias_kind":"pith_short_8","alias_value":"W5NEKPJR","created_at":"2026-05-18T12:28:54Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2014:W5NEKPJRYHPN52JOVTY5XRZL6M","target":"record","payload":{"canonical_record":{"source":{"id":"1405.6945","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2014-05-25T22:22:04Z","cross_cats_sorted":[],"title_canon_sha256":"c7fbbd4b9a708f3fa9f51a34a4c3e2cabf71b70e57481a5001ff5257fc168c1e","abstract_canon_sha256":"e3fd016e0527b11f5cd89aa8fa88c7f424e251a5e56f6ab0a8a7253922e8fb3f"},"schema_version":"1.0"},"canonical_sha256":"b75a453d31c1dedee92eacf1dbc72bf3010339b6b5918688a395a1e81ca3c3ed","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:51:00.060623Z","signature_b64":"/cm7MuHAE7+Q0v+ZJTdFhRNJ/14qvey0Qhh6lOF4IEsxS8LauH3e+09Ow+yj1GfbIyV48YAVm5IwwBnPwZErDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b75a453d31c1dedee92eacf1dbc72bf3010339b6b5918688a395a1e81ca3c3ed","last_reissued_at":"2026-05-18T02:51:00.060185Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:51:00.060185Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1405.6945","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":"2026-05-18T02:51:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"aHkzeLpocH+UIVH7rTiP9qu2TPHcAdWiXuxspLD4AefdAnL1yx7QhXpeKa/QTSDRQubLRhEgsobuH8uI3l0KDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T08:04:39.733749Z"},"content_sha256":"45d9e5233d575c2b0dba31356984040f74d6f21e97c9bd7e178765bd9e7c5808","schema_version":"1.0","event_id":"sha256:45d9e5233d575c2b0dba31356984040f74d6f21e97c9bd7e178765bd9e7c5808"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2014:W5NEKPJRYHPN52JOVTY5XRZL6M","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Sparsity-Aware Filtered-X Affine Projection Algorithms for Active Noise Control","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.SD","authors_text":"A.Gully, R. C. de Lamare","submitted_at":"2014-05-25T22:22:04Z","abstract_excerpt":"This paper describes a novel technique for promoting sparsity in the modified filtered-x algorithms required for active noise control. The proposed algorithms are based on recent techniques incorporating approximations to the \\ell_0-norm in the cost functions that are used to derive adaptive filtering algorithms. In particular, zero-attracting and reweighted zero-attracting filtered-x adaptive algorithms are developed and considered for active noise control problems. The results of simulations indicate that the proposed techniques improve the convergence of the existing modified algorithm in t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.6945","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":"2026-05-18T02:51:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"diZPPQUKugYv9Uql/bBxFkC6AmBfLdNJH381s7Bb2EBKXoUXKu0iNYeLyIOAS6Za1Kn83umfOfkx4u1wYdBtBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T08:04:39.734350Z"},"content_sha256":"5a4d0eec0feffe144dfc291dbca000ff69b805705afb0cc74d58ee3238ca55d5","schema_version":"1.0","event_id":"sha256:5a4d0eec0feffe144dfc291dbca000ff69b805705afb0cc74d58ee3238ca55d5"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/bundle.json","state_url":"https://pith.science/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/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":"2026-05-25T08:04:39Z","links":{"resolver":"https://pith.science/pith/W5NEKPJRYHPN52JOVTY5XRZL6M","bundle":"https://pith.science/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/bundle.json","state":"https://pith.science/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/state.json","well_known_bundle":"https://pith.science/.well-known/pith/W5NEKPJRYHPN52JOVTY5XRZL6M/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2014:W5NEKPJRYHPN52JOVTY5XRZL6M","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":"e3fd016e0527b11f5cd89aa8fa88c7f424e251a5e56f6ab0a8a7253922e8fb3f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2014-05-25T22:22:04Z","title_canon_sha256":"c7fbbd4b9a708f3fa9f51a34a4c3e2cabf71b70e57481a5001ff5257fc168c1e"},"schema_version":"1.0","source":{"id":"1405.6945","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1405.6945","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"arxiv_version","alias_value":"1405.6945v1","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1405.6945","created_at":"2026-05-18T02:51:00Z"},{"alias_kind":"pith_short_12","alias_value":"W5NEKPJRYHPN","created_at":"2026-05-18T12:28:54Z"},{"alias_kind":"pith_short_16","alias_value":"W5NEKPJRYHPN52JO","created_at":"2026-05-18T12:28:54Z"},{"alias_kind":"pith_short_8","alias_value":"W5NEKPJR","created_at":"2026-05-18T12:28:54Z"}],"graph_snapshots":[{"event_id":"sha256:5a4d0eec0feffe144dfc291dbca000ff69b805705afb0cc74d58ee3238ca55d5","target":"graph","created_at":"2026-05-18T02:51:00Z","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":"This paper describes a novel technique for promoting sparsity in the modified filtered-x algorithms required for active noise control. The proposed algorithms are based on recent techniques incorporating approximations to the \\ell_0-norm in the cost functions that are used to derive adaptive filtering algorithms. In particular, zero-attracting and reweighted zero-attracting filtered-x adaptive algorithms are developed and considered for active noise control problems. The results of simulations indicate that the proposed techniques improve the convergence of the existing modified algorithm in t","authors_text":"A.Gully, R. C. de Lamare","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2014-05-25T22:22:04Z","title":"Sparsity-Aware Filtered-X Affine Projection Algorithms for Active Noise Control"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1405.6945","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":"sha256:45d9e5233d575c2b0dba31356984040f74d6f21e97c9bd7e178765bd9e7c5808","target":"record","created_at":"2026-05-18T02:51:00Z","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":"e3fd016e0527b11f5cd89aa8fa88c7f424e251a5e56f6ab0a8a7253922e8fb3f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.SD","submitted_at":"2014-05-25T22:22:04Z","title_canon_sha256":"c7fbbd4b9a708f3fa9f51a34a4c3e2cabf71b70e57481a5001ff5257fc168c1e"},"schema_version":"1.0","source":{"id":"1405.6945","kind":"arxiv","version":1}},"canonical_sha256":"b75a453d31c1dedee92eacf1dbc72bf3010339b6b5918688a395a1e81ca3c3ed","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b75a453d31c1dedee92eacf1dbc72bf3010339b6b5918688a395a1e81ca3c3ed","first_computed_at":"2026-05-18T02:51:00.060185Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:51:00.060185Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"/cm7MuHAE7+Q0v+ZJTdFhRNJ/14qvey0Qhh6lOF4IEsxS8LauH3e+09Ow+yj1GfbIyV48YAVm5IwwBnPwZErDw==","signature_status":"signed_v1","signed_at":"2026-05-18T02:51:00.060623Z","signed_message":"canonical_sha256_bytes"},"source_id":"1405.6945","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:45d9e5233d575c2b0dba31356984040f74d6f21e97c9bd7e178765bd9e7c5808","sha256:5a4d0eec0feffe144dfc291dbca000ff69b805705afb0cc74d58ee3238ca55d5"],"state_sha256":"b9d0ebd5069d6b8abb2a58e8b074f208fd12de218f22d2dbb419c4897ccc6596"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/t9zsTvuGJbk6YrYnhrOlMK6aJPl9gbLixFI68FI3V732rr96jVDv0CaAxvjFk154IavK/avuYFeODtl+nLLCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T08:04:39.736830Z","bundle_sha256":"aa1f25fd8a6c7a7c49a601302a700d9e135e46bceae5edde80f9711547f0bec4"}}