{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:PXBR7F3JKAJDW2JH6J7XPT2CZB","short_pith_number":"pith:PXBR7F3J","canonical_record":{"source":{"id":"2103.14552","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"math.NA","submitted_at":"2021-03-26T16:12:47Z","cross_cats_sorted":["cs.NA"],"title_canon_sha256":"a528559d7fb1283d5d4ff3ed8853a57b10abb2d554d5445c499527dedcf8e281","abstract_canon_sha256":"a3f58118e87a0e905f65ee16f4f95e974fa49df6f9f27da695f0d3494d3a5b3a"},"schema_version":"1.0"},"canonical_sha256":"7dc31f976950123b6927f27f77cf42c877dfb78f170f2b4a592ff4f15ce46842","source":{"kind":"arxiv","id":"2103.14552","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2103.14552","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"arxiv_version","alias_value":"2103.14552v2","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2103.14552","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_12","alias_value":"PXBR7F3JKAJD","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_16","alias_value":"PXBR7F3JKAJDW2JH","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_8","alias_value":"PXBR7F3J","created_at":"2026-07-05T02:26:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:PXBR7F3JKAJDW2JH6J7XPT2CZB","target":"record","payload":{"canonical_record":{"source":{"id":"2103.14552","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"math.NA","submitted_at":"2021-03-26T16:12:47Z","cross_cats_sorted":["cs.NA"],"title_canon_sha256":"a528559d7fb1283d5d4ff3ed8853a57b10abb2d554d5445c499527dedcf8e281","abstract_canon_sha256":"a3f58118e87a0e905f65ee16f4f95e974fa49df6f9f27da695f0d3494d3a5b3a"},"schema_version":"1.0"},"canonical_sha256":"7dc31f976950123b6927f27f77cf42c877dfb78f170f2b4a592ff4f15ce46842","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:26:58.035779Z","signature_b64":"I89YsUK4grsEO5c64yLfkOg1yvz4mj9CgERd4okTjOFEfi0KiI0HFB2mU1CVH3OlyINuNeLv5Cu4Dv5xShqvBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7dc31f976950123b6927f27f77cf42c877dfb78f170f2b4a592ff4f15ce46842","last_reissued_at":"2026-07-05T02:26:58.035341Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:26:58.035341Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2103.14552","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T02:26:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UpG4dBLw18nHyCTnOK4DNmhSNRsKEv6Q9iBrSZ0XP65ovtJ1JTgmDENf00znXUASQRghI0MvP0TLIBhTWLQeAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T14:53:17.134503Z"},"content_sha256":"d5f8ed3fc6ba6da0060219ec77ebb4b3e7a86d88dfe9b2eb6f5c073c2e517e18","schema_version":"1.0","event_id":"sha256:d5f8ed3fc6ba6da0060219ec77ebb4b3e7a86d88dfe9b2eb6f5c073c2e517e18"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:PXBR7F3JKAJDW2JH6J7XPT2CZB","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Multilevel Active-Set Trust-Region (MASTR) Method for Bound Constrained Minimization","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":["cs.NA"],"primary_cat":"math.NA","authors_text":"Alena Kopani\\v{c}\\'akov\\'a, Rolf Krause","submitted_at":"2021-03-26T16:12:47Z","abstract_excerpt":"We introduce a novel variant of the recursive multilevel trust-region (RMTR) method, called MASTR. The method is designed for solving non-convex bound-constrained minimization problems, which arise from the finite element discretization of partial differential equations. MASTR utilizes an active-set strategy based on the truncated basis approach in order to preserve the variable bounds defined on the finest level by the coarser levels. Usage of this approach allows for fast convergence of the MASTR method, especially once the exact active-set is detected. The efficiency of the method is demons"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2103.14552","kind":"arxiv","version":2},"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/2103.14552/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":"2026-07-05T02:26:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"L9gONfiGU/AlQePFxBDtd7ZSR3xcKk40g/ymKrhs3PVOn/I7lu2JVGS2yXUH/vuchaN26oH/iNN/ar6HoEhdAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T14:53:17.134879Z"},"content_sha256":"2ae5b5d2740c62551eaf9a91fbf62f8436b609ffa8e2016022ba7a987d222151","schema_version":"1.0","event_id":"sha256:2ae5b5d2740c62551eaf9a91fbf62f8436b609ffa8e2016022ba7a987d222151"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/bundle.json","state_url":"https://pith.science/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/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":"2026-07-06T14:53:17Z","links":{"resolver":"https://pith.science/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB","bundle":"https://pith.science/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/bundle.json","state":"https://pith.science/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PXBR7F3JKAJDW2JH6J7XPT2CZB/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:PXBR7F3JKAJDW2JH6J7XPT2CZB","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":"a3f58118e87a0e905f65ee16f4f95e974fa49df6f9f27da695f0d3494d3a5b3a","cross_cats_sorted":["cs.NA"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"math.NA","submitted_at":"2021-03-26T16:12:47Z","title_canon_sha256":"a528559d7fb1283d5d4ff3ed8853a57b10abb2d554d5445c499527dedcf8e281"},"schema_version":"1.0","source":{"id":"2103.14552","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2103.14552","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"arxiv_version","alias_value":"2103.14552v2","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2103.14552","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_12","alias_value":"PXBR7F3JKAJD","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_16","alias_value":"PXBR7F3JKAJDW2JH","created_at":"2026-07-05T02:26:58Z"},{"alias_kind":"pith_short_8","alias_value":"PXBR7F3J","created_at":"2026-07-05T02:26:58Z"}],"graph_snapshots":[{"event_id":"sha256:2ae5b5d2740c62551eaf9a91fbf62f8436b609ffa8e2016022ba7a987d222151","target":"graph","created_at":"2026-07-05T02:26:58Z","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/2103.14552/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We introduce a novel variant of the recursive multilevel trust-region (RMTR) method, called MASTR. The method is designed for solving non-convex bound-constrained minimization problems, which arise from the finite element discretization of partial differential equations. MASTR utilizes an active-set strategy based on the truncated basis approach in order to preserve the variable bounds defined on the finest level by the coarser levels. Usage of this approach allows for fast convergence of the MASTR method, especially once the exact active-set is detected. The efficiency of the method is demons","authors_text":"Alena Kopani\\v{c}\\'akov\\'a, Rolf Krause","cross_cats":["cs.NA"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"math.NA","submitted_at":"2021-03-26T16:12:47Z","title":"Multilevel Active-Set Trust-Region (MASTR) Method for Bound Constrained Minimization"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2103.14552","kind":"arxiv","version":2},"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:d5f8ed3fc6ba6da0060219ec77ebb4b3e7a86d88dfe9b2eb6f5c073c2e517e18","target":"record","created_at":"2026-07-05T02:26:58Z","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":"a3f58118e87a0e905f65ee16f4f95e974fa49df6f9f27da695f0d3494d3a5b3a","cross_cats_sorted":["cs.NA"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"math.NA","submitted_at":"2021-03-26T16:12:47Z","title_canon_sha256":"a528559d7fb1283d5d4ff3ed8853a57b10abb2d554d5445c499527dedcf8e281"},"schema_version":"1.0","source":{"id":"2103.14552","kind":"arxiv","version":2}},"canonical_sha256":"7dc31f976950123b6927f27f77cf42c877dfb78f170f2b4a592ff4f15ce46842","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"7dc31f976950123b6927f27f77cf42c877dfb78f170f2b4a592ff4f15ce46842","first_computed_at":"2026-07-05T02:26:58.035341Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:26:58.035341Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"I89YsUK4grsEO5c64yLfkOg1yvz4mj9CgERd4okTjOFEfi0KiI0HFB2mU1CVH3OlyINuNeLv5Cu4Dv5xShqvBg==","signature_status":"signed_v1","signed_at":"2026-07-05T02:26:58.035779Z","signed_message":"canonical_sha256_bytes"},"source_id":"2103.14552","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d5f8ed3fc6ba6da0060219ec77ebb4b3e7a86d88dfe9b2eb6f5c073c2e517e18","sha256:2ae5b5d2740c62551eaf9a91fbf62f8436b609ffa8e2016022ba7a987d222151"],"state_sha256":"0b1688b8483fcd5a88c4122b5bf5b8b7642e1163a5f73c36bdb3c8dc368e6688"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"oKV1AarKqbk/93LxxSDfDmpKK5uwDsHt4RdYANTaL7wRIjPBYjpF0T7mJCFEKWN/AVsav3O92goy32qDVhT6BQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-06T14:53:17.136945Z","bundle_sha256":"96b9f2c41c31603cb594e27180b824d934093ac83787ea54bce1e5a95c1fe50b"}}