{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:IMDV553VHH5OH6DXOWVSWZCYJZ","short_pith_number":"pith:IMDV553V","canonical_record":{"source":{"id":"2108.12804","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.flu-dyn","submitted_at":"2021-08-29T10:01:28Z","cross_cats_sorted":["nlin.CD"],"title_canon_sha256":"8aa1f19080fed067add9d00c0830237e23ba790a60da1980a1d72e0df03a63bf","abstract_canon_sha256":"5feea54450027a4ea1b1a8bc5e9d07dac69a91262288a4c689aa9d1e052a4954"},"schema_version":"1.0"},"canonical_sha256":"43075ef77539fae3f87775ab2b64584e7c57ff9c6289c75f5f525375159e6a76","source":{"kind":"arxiv","id":"2108.12804","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2108.12804","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"arxiv_version","alias_value":"2108.12804v1","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2108.12804","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_12","alias_value":"IMDV553VHH5O","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_16","alias_value":"IMDV553VHH5OH6DX","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_8","alias_value":"IMDV553V","created_at":"2026-07-05T03:09:35Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:IMDV553VHH5OH6DXOWVSWZCYJZ","target":"record","payload":{"canonical_record":{"source":{"id":"2108.12804","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.flu-dyn","submitted_at":"2021-08-29T10:01:28Z","cross_cats_sorted":["nlin.CD"],"title_canon_sha256":"8aa1f19080fed067add9d00c0830237e23ba790a60da1980a1d72e0df03a63bf","abstract_canon_sha256":"5feea54450027a4ea1b1a8bc5e9d07dac69a91262288a4c689aa9d1e052a4954"},"schema_version":"1.0"},"canonical_sha256":"43075ef77539fae3f87775ab2b64584e7c57ff9c6289c75f5f525375159e6a76","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:09:35.787711Z","signature_b64":"5cynk+xtYcvyZuKNOAIbqNVRbxyPhhY6gY65fWbFpCRTTG1S11U1GDtWClxf4JPvp8o/4jWIWgBFVfFiKJ1SBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"43075ef77539fae3f87775ab2b64584e7c57ff9c6289c75f5f525375159e6a76","last_reissued_at":"2026-07-05T03:09:35.787355Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:09:35.787355Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2108.12804","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":"2026-07-05T03:09:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"nVBi7YHHvhibIGWnXL5Oj3pFL9FnGporC8ssLJmUaKEoN+tp9EMxPsL3SHmdQxbSSQKC1XWZsF4DDkG6k6n+Aw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T11:28:37.459138Z"},"content_sha256":"f545721da12b0bfdc45b72b7f9fdaf8bdaf30e50fa4b517eef04b387f99b4a6a","schema_version":"1.0","event_id":"sha256:f545721da12b0bfdc45b72b7f9fdaf8bdaf30e50fa4b517eef04b387f99b4a6a"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:IMDV553VHH5OH6DXOWVSWZCYJZ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Sound induced by a simple impact oscillator","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["nlin.CD"],"primary_cat":"physics.flu-dyn","authors_text":"Kartik Venkatraman, S. P. Narla","submitted_at":"2021-08-29T10:01:28Z","abstract_excerpt":"Acoustic radiation due to vibration and impact of a spring-mass-damper oscillator whose motion is constrained by a barrier is analyzed at a field point in a free field. Impact between the mass and the barrier is modeled using a coefficient of restitution model. Non-linear behavior of the oscillator is observed due to motion constraint. Steady state response is studied using a bifurcation diagram. For small amplitudes of oscillation, the pressure perturbation by a vibrating mass in a compressible fluid is modeled as an acoustic dipole with its center at the equilibrium position of the mass and "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2108.12804","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2108.12804/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T03:09:35Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"E2l/8FwlFoTz+zG43tCgLAJBw6PPMpJ/TviRyPgovmFEew0YlJAS58RzqGf27fgPeurk0Dp9ANBH7hTziiyKDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-21T11:28:37.459655Z"},"content_sha256":"f9d280a8ff463bb043c6b68d8aad2a21d1117080ffd97a3577f2943aac26c7e4","schema_version":"1.0","event_id":"sha256:f9d280a8ff463bb043c6b68d8aad2a21d1117080ffd97a3577f2943aac26c7e4"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/bundle.json","state_url":"https://pith.science/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/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":"2026-08-21T11:28:37Z","links":{"resolver":"https://pith.science/pith/IMDV553VHH5OH6DXOWVSWZCYJZ","bundle":"https://pith.science/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/bundle.json","state":"https://pith.science/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IMDV553VHH5OH6DXOWVSWZCYJZ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:IMDV553VHH5OH6DXOWVSWZCYJZ","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":"5feea54450027a4ea1b1a8bc5e9d07dac69a91262288a4c689aa9d1e052a4954","cross_cats_sorted":["nlin.CD"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.flu-dyn","submitted_at":"2021-08-29T10:01:28Z","title_canon_sha256":"8aa1f19080fed067add9d00c0830237e23ba790a60da1980a1d72e0df03a63bf"},"schema_version":"1.0","source":{"id":"2108.12804","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2108.12804","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"arxiv_version","alias_value":"2108.12804v1","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2108.12804","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_12","alias_value":"IMDV553VHH5O","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_16","alias_value":"IMDV553VHH5OH6DX","created_at":"2026-07-05T03:09:35Z"},{"alias_kind":"pith_short_8","alias_value":"IMDV553V","created_at":"2026-07-05T03:09:35Z"}],"graph_snapshots":[{"event_id":"sha256:f9d280a8ff463bb043c6b68d8aad2a21d1117080ffd97a3577f2943aac26c7e4","target":"graph","created_at":"2026-07-05T03:09:35Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2108.12804/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Acoustic radiation due to vibration and impact of a spring-mass-damper oscillator whose motion is constrained by a barrier is analyzed at a field point in a free field. Impact between the mass and the barrier is modeled using a coefficient of restitution model. Non-linear behavior of the oscillator is observed due to motion constraint. Steady state response is studied using a bifurcation diagram. For small amplitudes of oscillation, the pressure perturbation by a vibrating mass in a compressible fluid is modeled as an acoustic dipole with its center at the equilibrium position of the mass and ","authors_text":"Kartik Venkatraman, S. P. Narla","cross_cats":["nlin.CD"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.flu-dyn","submitted_at":"2021-08-29T10:01:28Z","title":"Sound induced by a simple impact oscillator"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2108.12804","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:f545721da12b0bfdc45b72b7f9fdaf8bdaf30e50fa4b517eef04b387f99b4a6a","target":"record","created_at":"2026-07-05T03:09:35Z","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":"5feea54450027a4ea1b1a8bc5e9d07dac69a91262288a4c689aa9d1e052a4954","cross_cats_sorted":["nlin.CD"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.flu-dyn","submitted_at":"2021-08-29T10:01:28Z","title_canon_sha256":"8aa1f19080fed067add9d00c0830237e23ba790a60da1980a1d72e0df03a63bf"},"schema_version":"1.0","source":{"id":"2108.12804","kind":"arxiv","version":1}},"canonical_sha256":"43075ef77539fae3f87775ab2b64584e7c57ff9c6289c75f5f525375159e6a76","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"43075ef77539fae3f87775ab2b64584e7c57ff9c6289c75f5f525375159e6a76","first_computed_at":"2026-07-05T03:09:35.787355Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:09:35.787355Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"5cynk+xtYcvyZuKNOAIbqNVRbxyPhhY6gY65fWbFpCRTTG1S11U1GDtWClxf4JPvp8o/4jWIWgBFVfFiKJ1SBA==","signature_status":"signed_v1","signed_at":"2026-07-05T03:09:35.787711Z","signed_message":"canonical_sha256_bytes"},"source_id":"2108.12804","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f545721da12b0bfdc45b72b7f9fdaf8bdaf30e50fa4b517eef04b387f99b4a6a","sha256:f9d280a8ff463bb043c6b68d8aad2a21d1117080ffd97a3577f2943aac26c7e4"],"state_sha256":"9c7db24be7027e56076fa6846a94698b981926d605828ec0027dbffa1cac0cc0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"fl9ihDUSDfP8LRiaTmmVBLlCEhK6KCv1wWFw4eBb2jYhYyDTcKdtWMz4Ugp39B6K4QapxsaH295IJ4rf4M1DCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-21T11:28:37.464472Z","bundle_sha256":"89ca554bc5866815ed454af32e776055998a60a03ee0c612c4efa54f626cbd2c"}}