{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:2L2SKD4DUUUUJ7HLVO6BAZWGCO","short_pith_number":"pith:2L2SKD4D","canonical_record":{"source":{"id":"1312.5756","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-12-18T13:51:24Z","cross_cats_sorted":["physics.optics"],"title_canon_sha256":"1bca5c9eb3130f3c1cf189bbb6c70f6e8dafc52b6780941bf5eb14cfd7d873cb","abstract_canon_sha256":"1e79d93c303a0a301beae27a3e408350c03b6a52937a85b1648370187c940fc8"},"schema_version":"1.0"},"canonical_sha256":"d2f5250f83a52944fcebabbc1066c613850f3a44ad29919228ad409f34efb685","source":{"kind":"arxiv","id":"1312.5756","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1312.5756","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"arxiv_version","alias_value":"1312.5756v1","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1312.5756","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"pith_short_12","alias_value":"2L2SKD4DUUUU","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_16","alias_value":"2L2SKD4DUUUUJ7HL","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_8","alias_value":"2L2SKD4D","created_at":"2026-05-18T12:27:30Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:2L2SKD4DUUUUJ7HLVO6BAZWGCO","target":"record","payload":{"canonical_record":{"source":{"id":"1312.5756","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-12-18T13:51:24Z","cross_cats_sorted":["physics.optics"],"title_canon_sha256":"1bca5c9eb3130f3c1cf189bbb6c70f6e8dafc52b6780941bf5eb14cfd7d873cb","abstract_canon_sha256":"1e79d93c303a0a301beae27a3e408350c03b6a52937a85b1648370187c940fc8"},"schema_version":"1.0"},"canonical_sha256":"d2f5250f83a52944fcebabbc1066c613850f3a44ad29919228ad409f34efb685","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:45:43.651532Z","signature_b64":"BDPHDfWUiLuZs6SDUeuquc6RbdVxLIKQIdBTsgKIe+Q9cq9yBso6E7mB07azIIJ2p0k+V9uMvANSChCXZpPACw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d2f5250f83a52944fcebabbc1066c613850f3a44ad29919228ad409f34efb685","last_reissued_at":"2026-05-18T01:45:43.650803Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:45:43.650803Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1312.5756","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":"2026-05-18T01:45:43Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"IPptGyfmdT3q+6iUySAKJCLvWW3CI6CvStj7CQLtDVqkI1xtG4/CpKlpL2s/iSBs/R9BDdGE7bWTA1MsIKtrBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T21:57:47.086863Z"},"content_sha256":"3fcfe903d3ecc4ae872b3f33ca589f38bad5f88d39d1e57fc9060ab7db9df40f","schema_version":"1.0","event_id":"sha256:3fcfe903d3ecc4ae872b3f33ca589f38bad5f88d39d1e57fc9060ab7db9df40f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:2L2SKD4DUUUUJ7HLVO6BAZWGCO","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Achieving Selective Damage Interrogation and Sub-Wavelength Resolution in Thin Plates with Embedded Metamaterial Acoustic Lenses","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.optics"],"primary_cat":"cond-mat.mtrl-sci","authors_text":"Fabio Semperlotti, Hongfei Zhu","submitted_at":"2013-12-18T13:51:24Z","abstract_excerpt":"In this study, we present an approach to ultrasonic beamforming and high resolution identification of acoustic sources having critical implications for structural health monitoring technology. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. The ultrasonic beams can be steered by simply tuning the frequency o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1312.5756","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":"2026-05-18T01:45:43Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hiDK8MS6fzCk/9ufLWuyJgKkNWpmsMFzH3geS/W+sdz5jSGWty98Q09urR3GQ2EwlUz2blaojM+Hbzg9qnIDDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T21:57:47.087206Z"},"content_sha256":"5df91af963f542018eabfdfe4c94ef27dca2f17600725f52ba6736bf4e12c81d","schema_version":"1.0","event_id":"sha256:5df91af963f542018eabfdfe4c94ef27dca2f17600725f52ba6736bf4e12c81d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/bundle.json","state_url":"https://pith.science/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/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":"2026-06-23T21:57:47Z","links":{"resolver":"https://pith.science/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO","bundle":"https://pith.science/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/bundle.json","state":"https://pith.science/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/state.json","well_known_bundle":"https://pith.science/.well-known/pith/2L2SKD4DUUUUJ7HLVO6BAZWGCO/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:2L2SKD4DUUUUJ7HLVO6BAZWGCO","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":"1e79d93c303a0a301beae27a3e408350c03b6a52937a85b1648370187c940fc8","cross_cats_sorted":["physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-12-18T13:51:24Z","title_canon_sha256":"1bca5c9eb3130f3c1cf189bbb6c70f6e8dafc52b6780941bf5eb14cfd7d873cb"},"schema_version":"1.0","source":{"id":"1312.5756","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1312.5756","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"arxiv_version","alias_value":"1312.5756v1","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1312.5756","created_at":"2026-05-18T01:45:43Z"},{"alias_kind":"pith_short_12","alias_value":"2L2SKD4DUUUU","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_16","alias_value":"2L2SKD4DUUUUJ7HL","created_at":"2026-05-18T12:27:30Z"},{"alias_kind":"pith_short_8","alias_value":"2L2SKD4D","created_at":"2026-05-18T12:27:30Z"}],"graph_snapshots":[{"event_id":"sha256:5df91af963f542018eabfdfe4c94ef27dca2f17600725f52ba6736bf4e12c81d","target":"graph","created_at":"2026-05-18T01:45:43Z","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":"In this study, we present an approach to ultrasonic beamforming and high resolution identification of acoustic sources having critical implications for structural health monitoring technology. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. The ultrasonic beams can be steered by simply tuning the frequency o","authors_text":"Fabio Semperlotti, Hongfei Zhu","cross_cats":["physics.optics"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-12-18T13:51:24Z","title":"Achieving Selective Damage Interrogation and Sub-Wavelength Resolution in Thin Plates with Embedded Metamaterial Acoustic Lenses"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1312.5756","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":"sha256:3fcfe903d3ecc4ae872b3f33ca589f38bad5f88d39d1e57fc9060ab7db9df40f","target":"record","created_at":"2026-05-18T01:45:43Z","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":"1e79d93c303a0a301beae27a3e408350c03b6a52937a85b1648370187c940fc8","cross_cats_sorted":["physics.optics"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.mtrl-sci","submitted_at":"2013-12-18T13:51:24Z","title_canon_sha256":"1bca5c9eb3130f3c1cf189bbb6c70f6e8dafc52b6780941bf5eb14cfd7d873cb"},"schema_version":"1.0","source":{"id":"1312.5756","kind":"arxiv","version":1}},"canonical_sha256":"d2f5250f83a52944fcebabbc1066c613850f3a44ad29919228ad409f34efb685","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d2f5250f83a52944fcebabbc1066c613850f3a44ad29919228ad409f34efb685","first_computed_at":"2026-05-18T01:45:43.650803Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:45:43.650803Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"BDPHDfWUiLuZs6SDUeuquc6RbdVxLIKQIdBTsgKIe+Q9cq9yBso6E7mB07azIIJ2p0k+V9uMvANSChCXZpPACw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:45:43.651532Z","signed_message":"canonical_sha256_bytes"},"source_id":"1312.5756","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:3fcfe903d3ecc4ae872b3f33ca589f38bad5f88d39d1e57fc9060ab7db9df40f","sha256:5df91af963f542018eabfdfe4c94ef27dca2f17600725f52ba6736bf4e12c81d"],"state_sha256":"d4b8a02d678c55783210a1010b98c6d4c7a9d246fe49c49e1cecf3b4023a0aa0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"nYPQAq0h1G3un8sk9uc3KDgJGzdfgIsQpoWgR9sdCgw7hdELGHpjPtM7T2SyRI1EDyt6vN1a6jLm2Y8qqp+8Ag==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-23T21:57:47.089121Z","bundle_sha256":"0f9f06b6401e7e8c602568626d3c236c17b44e8fdaf78e41940a0cf9e153e8a5"}}