{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2016:YTLTSB7O7APH5Q5M5TXFA2TPUL","short_pith_number":"pith:YTLTSB7O","schema_version":"1.0","canonical_sha256":"c4d73907eef81e7ec3acecee506a6fa2e267b594efd94c5d30804d002cbe6103","source":{"kind":"arxiv","id":"1609.09561","version":1},"attestation_state":"computed","paper":{"title":"Optimal Sound Absorbing Structures","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.class-ph","authors_text":"Caixing Fu, Min Yang, Ping Sheng, Shuyu Chen","submitted_at":"2016-09-30T01:18:19Z","abstract_excerpt":"Causal nature of the acoustic response, for any materials or structures, dictates an inequality that relates the absorption spectrum of the sample to its thickness. We present a general recipe for constructing sound-absorbing structures that can attain near-equality for the causal relation with very high absorption performance; such structures are denoted optimal. Our strategy involves using carefully designed acoustic metamaterials as backing to a thin layer of conventional sound absorbing material, e.g., acoustic sponge. By using this design approach, we have realized a 12 cm-thick structure"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1609.09561","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.class-ph","submitted_at":"2016-09-30T01:18:19Z","cross_cats_sorted":[],"title_canon_sha256":"b9036a7cd56acbc9015b359f9590fe3d1102a5722086a6e7c574d0422a65ff87","abstract_canon_sha256":"b18d58a2e50768a7f1d5d657848e4c78516c618db9046344e46a1e53365127e8"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:16:46.419879Z","signature_b64":"aHddO1vBXVEBfUm7qwyT6QypUYFJheGOoL4glmz3rfOGe8uNEb69XUpMHZBmd/rfwBasc6b/0uAL1HImj4VnCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c4d73907eef81e7ec3acecee506a6fa2e267b594efd94c5d30804d002cbe6103","last_reissued_at":"2026-07-05T11:16:46.419358Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:16:46.419358Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Optimal Sound Absorbing Structures","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.class-ph","authors_text":"Caixing Fu, Min Yang, Ping Sheng, Shuyu Chen","submitted_at":"2016-09-30T01:18:19Z","abstract_excerpt":"Causal nature of the acoustic response, for any materials or structures, dictates an inequality that relates the absorption spectrum of the sample to its thickness. We present a general recipe for constructing sound-absorbing structures that can attain near-equality for the causal relation with very high absorption performance; such structures are denoted optimal. Our strategy involves using carefully designed acoustic metamaterials as backing to a thin layer of conventional sound absorbing material, e.g., acoustic sponge. By using this design approach, we have realized a 12 cm-thick structure"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.09561","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/1609.09561/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1609.09561","created_at":"2026-07-05T11:16:46.419426+00:00"},{"alias_kind":"arxiv_version","alias_value":"1609.09561v1","created_at":"2026-07-05T11:16:46.419426+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1609.09561","created_at":"2026-07-05T11:16:46.419426+00:00"},{"alias_kind":"pith_short_12","alias_value":"YTLTSB7O7APH","created_at":"2026-07-05T11:16:46.419426+00:00"},{"alias_kind":"pith_short_16","alias_value":"YTLTSB7O7APH5Q5M","created_at":"2026-07-05T11:16:46.419426+00:00"},{"alias_kind":"pith_short_8","alias_value":"YTLTSB7O","created_at":"2026-07-05T11:16:46.419426+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL","json":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL.json","graph_json":"https://pith.science/api/pith-number/YTLTSB7O7APH5Q5M5TXFA2TPUL/graph.json","events_json":"https://pith.science/api/pith-number/YTLTSB7O7APH5Q5M5TXFA2TPUL/events.json","paper":"https://pith.science/paper/YTLTSB7O"},"agent_actions":{"view_html":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL","download_json":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL.json","view_paper":"https://pith.science/paper/YTLTSB7O","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1609.09561&json=true","fetch_graph":"https://pith.science/api/pith-number/YTLTSB7O7APH5Q5M5TXFA2TPUL/graph.json","fetch_events":"https://pith.science/api/pith-number/YTLTSB7O7APH5Q5M5TXFA2TPUL/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL/action/timestamp_anchor","attest_storage":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL/action/storage_attestation","attest_author":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL/action/author_attestation","sign_citation":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL/action/citation_signature","submit_replication":"https://pith.science/pith/YTLTSB7O7APH5Q5M5TXFA2TPUL/action/replication_record"}},"created_at":"2026-07-05T11:16:46.419426+00:00","updated_at":"2026-07-05T11:16:46.419426+00:00"}