{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:Y4T2ETOT55QU63KZVND3GAEGQA","short_pith_number":"pith:Y4T2ETOT","canonical_record":{"source":{"id":"0904.4635","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2009-04-29T15:31:41Z","cross_cats_sorted":[],"title_canon_sha256":"301ce2aff67a268ac6deffb6ac2636018d230fd842bfc809333897f23039de79","abstract_canon_sha256":"0ecf481b47cf6252b0e0fa219c2f72530b0d0c38a83c79c70b6ae3ea1144c075"},"schema_version":"1.0"},"canonical_sha256":"c727a24dd3ef614f6d59ab47b30086802818328645cd2d9f0c6f41b6a2079394","source":{"kind":"arxiv","id":"0904.4635","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.4635","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"arxiv_version","alias_value":"0904.4635v1","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.4635","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"pith_short_12","alias_value":"Y4T2ETOT55QU","created_at":"2026-05-18T12:26:02Z"},{"alias_kind":"pith_short_16","alias_value":"Y4T2ETOT55QU63KZ","created_at":"2026-05-18T12:26:02Z"},{"alias_kind":"pith_short_8","alias_value":"Y4T2ETOT","created_at":"2026-05-18T12:26:02Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:Y4T2ETOT55QU63KZVND3GAEGQA","target":"record","payload":{"canonical_record":{"source":{"id":"0904.4635","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2009-04-29T15:31:41Z","cross_cats_sorted":[],"title_canon_sha256":"301ce2aff67a268ac6deffb6ac2636018d230fd842bfc809333897f23039de79","abstract_canon_sha256":"0ecf481b47cf6252b0e0fa219c2f72530b0d0c38a83c79c70b6ae3ea1144c075"},"schema_version":"1.0"},"canonical_sha256":"c727a24dd3ef614f6d59ab47b30086802818328645cd2d9f0c6f41b6a2079394","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:58:20.206248Z","signature_b64":"Ref2BQxTECrM6bSknrSnZoRvdVH4Iw1Rzc9QalN/pUWObQmvcVwtpAoZF2BYNu3P1+ISBM2bPoA33QC/uJmQAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"c727a24dd3ef614f6d59ab47b30086802818328645cd2d9f0c6f41b6a2079394","last_reissued_at":"2026-05-18T00:58:20.205398Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:58:20.205398Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0904.4635","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":"2026-05-18T00:58:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sa/yfq3nBsPMHp4SZxaH4Dicy/+vKTFaq06Mf9/Obb4+4cA0K2WBrQO6M6p0BJfNsRvKP46+FbEdZcjRUvwSAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T20:53:36.367642Z"},"content_sha256":"76ee24ddf5794ed8a2b126915443f5b3c6d292d63955de8d756e3942c3a0da5e","schema_version":"1.0","event_id":"sha256:76ee24ddf5794ed8a2b126915443f5b3c6d292d63955de8d756e3942c3a0da5e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:Y4T2ETOT55QU63KZVND3GAEGQA","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A Variable Splitting Augmented Lagrangian Approach to Linear Spectral Unmixing","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.OC","authors_text":"Jose Bioucas-Dias","submitted_at":"2009-04-29T15:31:41Z","abstract_excerpt":"This paper presents a new linear hyperspectral unmixing method of the minimum volume class, termed \\emph{simplex identification via split augmented Lagrangian} (SISAL). Following Craig's seminal ideas, hyperspectral linear unmixing amounts to finding the minimum volume simplex containing the hyperspectral vectors. This is a nonconvex optimization problem with convex constraints. In the proposed approach, the positivity constraints, forcing the spectral vectors to belong to the convex hull of the endmember signatures, are replaced by soft constraints. The obtained problem is solved by a sequenc"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.4635","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":"2026-05-18T00:58:20Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2Q3LDS6H8z1LygLkxurnBKXjQWb9pnO597U7NV5Hhe4WuEmRdkv+X5x7OPmSz3Q9pgNLcjEYPEqScMNcIRHHDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-23T20:53:36.367986Z"},"content_sha256":"cc5ad72bff84d2179df808fef60eecae77b520b5561156ac7c604e79be59b9fa","schema_version":"1.0","event_id":"sha256:cc5ad72bff84d2179df808fef60eecae77b520b5561156ac7c604e79be59b9fa"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/Y4T2ETOT55QU63KZVND3GAEGQA/bundle.json","state_url":"https://pith.science/pith/Y4T2ETOT55QU63KZVND3GAEGQA/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/Y4T2ETOT55QU63KZVND3GAEGQA/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":"2026-06-23T20:53:36Z","links":{"resolver":"https://pith.science/pith/Y4T2ETOT55QU63KZVND3GAEGQA","bundle":"https://pith.science/pith/Y4T2ETOT55QU63KZVND3GAEGQA/bundle.json","state":"https://pith.science/pith/Y4T2ETOT55QU63KZVND3GAEGQA/state.json","well_known_bundle":"https://pith.science/.well-known/pith/Y4T2ETOT55QU63KZVND3GAEGQA/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:Y4T2ETOT55QU63KZVND3GAEGQA","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":"0ecf481b47cf6252b0e0fa219c2f72530b0d0c38a83c79c70b6ae3ea1144c075","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2009-04-29T15:31:41Z","title_canon_sha256":"301ce2aff67a268ac6deffb6ac2636018d230fd842bfc809333897f23039de79"},"schema_version":"1.0","source":{"id":"0904.4635","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.4635","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"arxiv_version","alias_value":"0904.4635v1","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.4635","created_at":"2026-05-18T00:58:20Z"},{"alias_kind":"pith_short_12","alias_value":"Y4T2ETOT55QU","created_at":"2026-05-18T12:26:02Z"},{"alias_kind":"pith_short_16","alias_value":"Y4T2ETOT55QU63KZ","created_at":"2026-05-18T12:26:02Z"},{"alias_kind":"pith_short_8","alias_value":"Y4T2ETOT","created_at":"2026-05-18T12:26:02Z"}],"graph_snapshots":[{"event_id":"sha256:cc5ad72bff84d2179df808fef60eecae77b520b5561156ac7c604e79be59b9fa","target":"graph","created_at":"2026-05-18T00:58:20Z","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 presents a new linear hyperspectral unmixing method of the minimum volume class, termed \\emph{simplex identification via split augmented Lagrangian} (SISAL). Following Craig's seminal ideas, hyperspectral linear unmixing amounts to finding the minimum volume simplex containing the hyperspectral vectors. This is a nonconvex optimization problem with convex constraints. In the proposed approach, the positivity constraints, forcing the spectral vectors to belong to the convex hull of the endmember signatures, are replaced by soft constraints. The obtained problem is solved by a sequenc","authors_text":"Jose Bioucas-Dias","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2009-04-29T15:31:41Z","title":"A Variable Splitting Augmented Lagrangian Approach to Linear Spectral Unmixing"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.4635","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":"sha256:76ee24ddf5794ed8a2b126915443f5b3c6d292d63955de8d756e3942c3a0da5e","target":"record","created_at":"2026-05-18T00:58:20Z","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":"0ecf481b47cf6252b0e0fa219c2f72530b0d0c38a83c79c70b6ae3ea1144c075","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.OC","submitted_at":"2009-04-29T15:31:41Z","title_canon_sha256":"301ce2aff67a268ac6deffb6ac2636018d230fd842bfc809333897f23039de79"},"schema_version":"1.0","source":{"id":"0904.4635","kind":"arxiv","version":1}},"canonical_sha256":"c727a24dd3ef614f6d59ab47b30086802818328645cd2d9f0c6f41b6a2079394","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"c727a24dd3ef614f6d59ab47b30086802818328645cd2d9f0c6f41b6a2079394","first_computed_at":"2026-05-18T00:58:20.205398Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:58:20.205398Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Ref2BQxTECrM6bSknrSnZoRvdVH4Iw1Rzc9QalN/pUWObQmvcVwtpAoZF2BYNu3P1+ISBM2bPoA33QC/uJmQAg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:58:20.206248Z","signed_message":"canonical_sha256_bytes"},"source_id":"0904.4635","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:76ee24ddf5794ed8a2b126915443f5b3c6d292d63955de8d756e3942c3a0da5e","sha256:cc5ad72bff84d2179df808fef60eecae77b520b5561156ac7c604e79be59b9fa"],"state_sha256":"7de6fa7db2cf06e469fdf0c2a9e91b42688b73afae9ca9c093ba7de4d382bfb7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"wfiaGnrPT16oDUPkoAhou5qKT989LwOwzg32DgGjQec/G0bAUyFjh57XAXWDsLk9lXHlTE3+p1HJ/SQKooOKCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-23T20:53:36.369902Z","bundle_sha256":"ed5d815f002a0c1dcfca6a4563199da6d93e193d5557efe7e982060cb0415854"}}