| { |
| "body_sha256": "49f932d4c234baf0a869aa614b963990e6538dd1a59f3f41d75e7e3e4620a0f6", |
| "caveats": { |
| "echo_spacing": "Only their te = 100 us train is reproduced: it is the one their relaxivities were fitted on. The te-DEPENDENCE of their trains (100 us to 20 ms) IS the garnet's internal-gradient effect, and a label-volume pack carries no C3 field channel, so a longer-te train is refused by name rather than served as a decay without its dephasing.", |
| "grade": "The pre-protocol record of this family stated grade B as a FIELD, reasoning that the paper prints no T2 value. grade_of assigns A by rule: the quantity is read from their own RELEASED echo trains, which ARE the measurement, on the same physical object. What the absence of a printed number costs is the reference's uncertainty -- it is 0.0 with a reason, so the `published-` comparison cannot be failed on and its disagreement is recorded instead.", |
| "mixtures": "The three MIXTURES have no reference row. LabelVolume accumulates ONE boundary local time over every wall and Tissue.rho is one scalar, so a single pack cannot carry Ling's 12.5 um/s on quartz and 98.5 um/s on garnet at once. They are built, certified, gated and published -- the geometry, the positions and the contact channel are all sound -- and their spec declares NO nominal relaxivity, so a consumer must state one. Recorded as blocked (dmipy-sim#491), not approximated with one of the two numbers.", |
| "windows": "The five packs do not share a window: 3.5 s for the two quartz-rich packs (35,000 echoes) and 2.0 s for the three garnet-rich ones (20,000 echoes), each the extent of ITS OWN released train. The design's window is the longest and each pack's own is in the walk record." |
| }, |
| "crossref": { |
| "agency": "crossref", |
| "container": "Transport in Porous Media", |
| "doi": "10.1007/s11242-022-01764-w", |
| "resolved": "2026-09-27T01:17:40Z", |
| "title": "Model Synthetic Samples for Validation of NMR Signal Simulations", |
| "type": "journal-article" |
| }, |
| "description": "Resin-set quartz and garnet sand packs whose CPMG was measured and whose pore space was then imaged: the relaxometry reference where the measurement and the geometry are the SAME object. Relaxation is not in the walk, so one pack answers every relaxivity.", |
| "doi": "10.1007/s11242-022-01764-w", |
| "geometry_derivation": "the geometry is the released one when no free parameter marked 'ours' changes it; none of this family's parameters does", |
| "geometry_parameters_ours": [], |
| "inputs_sha256": "441526872b5bd57169d88f18d0974666682d06d84acc8d34502e1362bc3bd174", |
| "licence_note": "CC-BY-4.0 images and echo trains; the packs are CC-BY-4.0 and no byte of the deposit is redistributed", |
| "parameters": [ |
| { |
| "changes_geometry": false, |
| "how": "fitted by them per mineral to their own te = 100 us trains; an effective value tied to their 3.93 um voxel, because a segmentation's surface is the Manhattan area at that resolution, which is what both walks relax against", |
| "name": "rho", |
| "unit": "m/s", |
| "value": { |
| "garnet": 9.85e-05, |
| "quartz": 1.25e-05 |
| }, |
| "where": "paper \u00a73.2", |
| "whose": "theirs" |
| }, |
| { |
| "changes_geometry": false, |
| "how": "the brine's self-diffusion, stated", |
| "name": "D0", |
| "unit": "m^2/s", |
| "value": 2.3e-09, |
| "where": "paper \u00a72.3", |
| "whose": "theirs" |
| }, |
| { |
| "changes_geometry": false, |
| "how": "the paper states no bulk T2; 3.0 s is ours, applied at replay and not in the walk, and the reproduction reports the log-mean over 2.4-3.1 s as well", |
| "name": "T2B", |
| "unit": "s", |
| "value": 3.0, |
| "where": "not in the paper", |
| "whose": "ours" |
| }, |
| { |
| "changes_geometry": false, |
| "how": "non-negative least squares with a second-difference penalty on 60 points from 1 ms, applied to THEIR released train and to ours identically, so the two sides of the comparison share the estimator even though it is not theirs", |
| "name": "T2 inversion", |
| "unit": "-", |
| "value": "non-negative least squares with a second-difference penalty, lam = 0.1 (t2_distribution)", |
| "where": "the paper states its own only as a regularised inversion", |
| "whose": "ours" |
| }, |
| { |
| "changes_geometry": false, |
| "how": "the boundary local time is stored as a channel and weighted at replay; their walk kills a walker at an attempted move into a grain voxel. The two agree in the continuum limit", |
| "name": "surface rule", |
| "unit": "-", |
| "value": "exp(-2 (rho/D) d_perp) per reflection", |
| "where": "the walk", |
| "whose": "ours" |
| } |
| ], |
| "previous_sha256": "4ad52625c812a8f904e346b41e1f6793b8418f430fddc402abe67c5111813023", |
| "published_kind": "data", |
| "quantities": [ |
| { |
| "direct": { |
| "grid": { |
| "from_s": 0.001, |
| "kind": "log", |
| "n": 60, |
| "sample_ms": 1.0, |
| "solver": "non-negative least squares with a second-difference penalty, lam = 0.1 (t2_distribution)", |
| "to_s": 10.0 |
| }, |
| "n_walkers": 200000, |
| "se": 0.001101402177425109, |
| "se_derivation": "the delta method over walkers on the log-mean (talabi_micro_ct_rocks.log_mean_gradient), MEASURED at record time on this family's own 6_q100.rpk -- 0.001366 over 130,000 walkers at the same rho, channel and grid -- and scaled to the direct walk's 200,000 by 1/sqrt(N) (x 0.806226). The direct walk's own per-walker decays were not retained; the relative per-echo spread is a property of the substrate and the estimator, not of the pack", |
| "se_kind": "delta_method", |
| "solver": "non-negative least squares with a second-difference penalty, lam = 0.1 (t2_distribution)", |
| "source": "examples/validation/ling_sand_packs.py, recorded in this family's direct.json by the DIRECT fused-engine walk at the walker count and step stated with it; that walk is read, never repeated", |
| "unit": "ms", |
| "value": 856.54 |
| }, |
| "documents": { |
| "10.1007/s11242-022-01764-w": { |
| "agency": "crossref", |
| "container": "Transport in Porous Media", |
| "doi": "10.1007/s11242-022-01764-w", |
| "resolved": "2026-09-27T01:17:40Z", |
| "title": "Model Synthetic Samples for Validation of NMR Signal Simulations", |
| "type": "journal-article" |
| } |
| }, |
| "name": "T2_log_mean", |
| "published": { |
| "data_sha256": "a9e09a21776d4c3f2c24f017547e75da1322ae19251569017f8b0c480d716eae", |
| "data_url": "https://doi.org/10.6084/m9.figshare.17161730", |
| "document": "10.1007/s11242-022-01764-w", |
| "locator": "the log-mean of the released te = 100 us CPMG train of sample 6_Q100, inverted on the 1 ms grid with the same estimator as ours", |
| "printed_in": "Model Synthetic Samples for Validation of NMR Signal Simulations (Ling et al. 2022), whose released te = 100 us echo train the value is read from", |
| "uncertainty": 0.0, |
| "uncertainty_is": "none stated: the paper prints no T2 value anywhere -- its comparison is Fig. 5, two distributions overlaid with no agreement metric -- and the released echo train carries no repeat, so the gate's budget rests on our own standard errors alone and the disagreement with them is recorded rather than failed on", |
| "unit": "ms", |
| "value": 727.084, |
| "verbatim": "" |
| }, |
| "substrate": "6_Q100" |
| }, |
| { |
| "direct": { |
| "grid": { |
| "from_s": 0.001, |
| "kind": "log", |
| "n": 60, |
| "sample_ms": 1.0, |
| "solver": "non-negative least squares with a second-difference penalty, lam = 0.1 (t2_distribution)", |
| "to_s": 10.0 |
| }, |
| "n_walkers": 200000, |
| "se": 0.002699867506755278, |
| "se_derivation": "the delta method over walkers on the log-mean (talabi_micro_ct_rocks.log_mean_gradient), MEASURED at record time on this family's own 1_g100.rpk -- 0.003349 over 130,000 walkers at the same rho, channel and grid -- and scaled to the direct walk's 200,000 by 1/sqrt(N) (x 0.806226). The direct walk's own per-walker decays were not retained; the relative per-echo spread is a property of the substrate and the estimator, not of the pack", |
| "se_kind": "delta_method", |
| "solver": "non-negative least squares with a second-difference penalty, lam = 0.1 (t2_distribution)", |
| "source": "examples/validation/ling_sand_packs.py, recorded in this family's direct.json by the DIRECT fused-engine walk at the walker count and step stated with it; that walk is read, never repeated", |
| "unit": "ms", |
| "value": 223.26 |
| }, |
| "documents": { |
| "10.1007/s11242-022-01764-w": { |
| "agency": "crossref", |
| "container": "Transport in Porous Media", |
| "doi": "10.1007/s11242-022-01764-w", |
| "resolved": "2026-09-27T01:17:40Z", |
| "title": "Model Synthetic Samples for Validation of NMR Signal Simulations", |
| "type": "journal-article" |
| } |
| }, |
| "name": "T2_log_mean", |
| "published": { |
| "data_sha256": "0eb1de561db7930e31726105bd8f171e68a53db0997f8521f911c804c3093ebe", |
| "data_url": "https://doi.org/10.6084/m9.figshare.17161730", |
| "document": "10.1007/s11242-022-01764-w", |
| "locator": "the log-mean of the released te = 100 us CPMG train of sample 1_G100, inverted on the 1 ms grid with the same estimator as ours", |
| "printed_in": "Model Synthetic Samples for Validation of NMR Signal Simulations (Ling et al. 2022), whose released te = 100 us echo train the value is read from", |
| "uncertainty": 0.0, |
| "uncertainty_is": "none stated: the paper prints no T2 value anywhere -- its comparison is Fig. 5, two distributions overlaid with no agreement metric -- and the released echo train carries no repeat, so the gate's budget rests on our own standard errors alone and the disagreement with them is recorded rather than failed on", |
| "unit": "ms", |
| "value": 178.449, |
| "verbatim": "" |
| }, |
| "substrate": "1_G100" |
| } |
| ], |
| "same_released_geometry": true, |
| "sample": "the same physical object: the CPMG was measured on each pack, which was then resin-set and micro-CT imaged, and both halves are in the same deposit", |
| "sample_relation": "the same object", |
| "source_note": "Ling et al. 2022 (Transport in Porous Media 142:623-639) for the packs, the measured CPMG and the fitted relaxivities; the micro-CT lattices and the echo trains are both in the figshare deposit 10.6084/m9.figshare.17161730 (CC BY 4.0).", |
| "stage": "reference", |
| "title": "Model Synthetic Samples for Validation of NMR Signal Simulations", |
| "title_matches": true |
| } |
