{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:2VD2MCHOL4QRWGU45BWLWUZSAX","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":"27a50e43ff95c3cd0878ba3bbdd9156103b5480349f73ca8b5c8eb61a53d9131","cross_cats_sorted":["cs.NA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DC","submitted_at":"2009-12-14T04:01:05Z","title_canon_sha256":"a46b36e14713b4a4df214049d43cd67c32a099a2e70efcb4478794013141ab84"},"schema_version":"1.0","source":{"id":"0912.2572","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0912.2572","created_at":"2026-05-18T00:59:11Z"},{"alias_kind":"arxiv_version","alias_value":"0912.2572v1","created_at":"2026-05-18T00:59:11Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0912.2572","created_at":"2026-05-18T00:59:11Z"},{"alias_kind":"pith_short_12","alias_value":"2VD2MCHOL4QR","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"2VD2MCHOL4QRWGU4","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"2VD2MCHO","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:844d35effc26b6780882042edd0412bf6e86d80df65413b2e8d20f01de79ea85","target":"graph","created_at":"2026-05-18T00:59:11Z","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":"Previous studies have reported that common dense linear algebra operations do not achieve speed up by using multiple geographical sites of a computational grid. Because such operations are the building blocks of most scientific applications, conventional supercomputers are still strongly predominant in high-performance computing and the use of grids for speeding up large-scale scientific problems is limited to applications exhibiting parallelism at a higher level. We have identified two performance bottlenecks in the distributed memory algorithms implemented in ScaLAPACK, a state-of-the-art de","authors_text":"Camille Coti, Emmanuel Agullo, Jack Dongarra, Julien Langou, Thomas Herault","cross_cats":["cs.NA"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DC","submitted_at":"2009-12-14T04:01:05Z","title":"QR Factorization of Tall and Skinny Matrices in a Grid Computing Environment"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0912.2572","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:e7d8e8dcebfc2cde8841831697e11da265b376383f04cc8d572b8dabea4f1963","target":"record","created_at":"2026-05-18T00:59:11Z","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":"27a50e43ff95c3cd0878ba3bbdd9156103b5480349f73ca8b5c8eb61a53d9131","cross_cats_sorted":["cs.NA"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DC","submitted_at":"2009-12-14T04:01:05Z","title_canon_sha256":"a46b36e14713b4a4df214049d43cd67c32a099a2e70efcb4478794013141ab84"},"schema_version":"1.0","source":{"id":"0912.2572","kind":"arxiv","version":1}},"canonical_sha256":"d547a608ee5f211b1a9ce86cbb533205dbe6d9e21429b2b333521a46a60a330a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d547a608ee5f211b1a9ce86cbb533205dbe6d9e21429b2b333521a46a60a330a","first_computed_at":"2026-05-18T00:59:11.131558Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:59:11.131558Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xLJFlRjt5q9BPSG7PP5p1sW5xg7nfHi1IbMVOh6pXG8Iyqa2AEBFM3pmdjlmz94j9dwwM55PW+IYy5uFg/TLBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:59:11.132208Z","signed_message":"canonical_sha256_bytes"},"source_id":"0912.2572","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e7d8e8dcebfc2cde8841831697e11da265b376383f04cc8d572b8dabea4f1963","sha256:844d35effc26b6780882042edd0412bf6e86d80df65413b2e8d20f01de79ea85"],"state_sha256":"7e332c5c3bd22ccfab3513838f28f68b26097c35104982fc764db695a0d6f08b"}