{"artifact_id":"L1-037","layer":"L1","title":"Dual-Energy X-ray Absorptiometry (DEXA)","domain":"Medical Imaging","sub_domain":"Bone mineral density via two-energy decomposition","physics_fingerprint":{"L_DAG":3.2,"title":"Dual-Energy X-ray Absorptiometry (DEXA)","domain":"Medical Imaging","carrier":"x_ray","primitives":["L.xray_source_dual","L.beer_lambert","L.two_material_decompose","int.spatial"],"sub_domain":"Bone mineral density via two-energy decomposition","noise_model":"shot_poisson","problem_class":"linear_inverse","solution_space":"2D_bone_mineral_density","difficulty_delta":3,"integration_axis":"spatial","sensing_mechanism":"dual_energy_xray"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 2D bone mineral density is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 10); beam_hardening dominates the stability cliff; patient_alignment and the remaining mismatch parameters contribute higher-order bias terms. Photon-shot-noise-limited (poisson counting) sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":1024,"W":512,"mAs":10,"kVp_hi":140,"kVp_lo":70,"pixel_mm":0.5,"beam_hardening":0.05,"patient_alignment":0.0,"fat_fraction_variation":0.0},"input_format":"measurement_only","problem_class":"dexa","forward_operator":"dexa_forward","epsilon_fn_center":"30.0"},"omega_bounds":{"H":512,"W":256,"mAs":[1,100],"kVp_hi":[100,150],"kVp_lo":[60,80],"pixel_mm":[0.1,2.0],"beam_hardening":[0.0,0.2],"calibration_drift":[0.0,0.05],"patient_alignment":[0.0,2.0],"fat_fraction_variation":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["dexa"],"allowed_omega_dimensions":["H","W","kVp_hi","kVp_lo","mAs","pixel_mm","beam_hardening","patient_alignment","fat_fraction_variation","beam_hardening","patient_alignment","fat_fraction_variation","calibration_drift"],"allowed_forward_operators":["dexa_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":200,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x1b180345715c22e98dce5616f472c3135d9d037edf910135ff5401bfb049afa0","chain_tx_hash":"0xa2c4275ad933053a705d24233547692e6480513eda72372e3e28e98e515152cb","chain_block":41552301}