{"id":"https://openalex.org/W7130420468","doi":"https://doi.org/10.48550/arxiv.2602.15637","title":"The Stationarity Bias: Stratified Stress-Testing for Time-Series Imputation in Regulated Dynamical Systems","display_name":"The Stationarity Bias: Stratified Stress-Testing for Time-Series Imputation in Regulated Dynamical Systems","publication_year":2026,"publication_date":"2026-02-17","ids":{"openalex":"https://openalex.org/W7130420468","doi":"https://doi.org/10.48550/arxiv.2602.15637"},"language":null,"primary_location":{"id":"doi:10.48550/arxiv.2602.15637","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2602.15637","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"},"type":"preprint","indexed_in":["datacite"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://doi.org/10.48550/arxiv.2602.15637","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5126304696","display_name":"Amirreza Dolatpour Fathkouhi","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Fathkouhi, Amirreza Dolatpour","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5126292268","display_name":"Alireza Namazi","orcid":null},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Namazi, Alireza","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"last","author":{"id":"https://openalex.org/A5006445265","display_name":"Heman Shakeri","orcid":"https://orcid.org/0000-0002-9891-5748"},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Shakeri, Heman","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11689","display_name":"Adversarial Robustness in Machine Learning","score":0.1371999979019165,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11689","display_name":"Adversarial Robustness in Machine Learning","score":0.1371999979019165,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10560","display_name":"Diabetes Management and Research","score":0.09910000115633011,"subfield":{"id":"https://openalex.org/subfields/2712","display_name":"Endocrinology, Diabetes and Metabolism"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10745","display_name":"Heart Rate Variability and Autonomic Control","score":0.06509999930858612,"subfield":{"id":"https://openalex.org/subfields/2705","display_name":"Cardiology and Cardiovascular Medicine"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/pointwise","display_name":"Pointwise","score":0.7675999999046326},{"id":"https://openalex.org/keywords/weighting","display_name":"Weighting","score":0.6556000113487244},{"id":"https://openalex.org/keywords/robustness","display_name":"Robustness (evolution)","score":0.5835000276565552},{"id":"https://openalex.org/keywords/testbed","display_name":"Testbed","score":0.5791000127792358},{"id":"https://openalex.org/keywords/dynamical-systems-theory","display_name":"Dynamical systems theory","score":0.5368000268936157},{"id":"https://openalex.org/keywords/observability","display_name":"Observability","score":0.4498000144958496},{"id":"https://openalex.org/keywords/benchmark","display_name":"Benchmark (surveying)","score":0.3978999853134155},{"id":"https://openalex.org/keywords/attractor","display_name":"Attractor","score":0.37860000133514404},{"id":"https://openalex.org/keywords/fidelity","display_name":"Fidelity","score":0.3785000145435333},{"id":"https://openalex.org/keywords/missing-data","display_name":"Missing data","score":0.3774999976158142}],"concepts":[{"id":"https://openalex.org/C2777984123","wikidata":"https://www.wikidata.org/wiki/Q9248237","display_name":"Pointwise","level":2,"score":0.7675999999046326},{"id":"https://openalex.org/C183115368","wikidata":"https://www.wikidata.org/wiki/Q856577","display_name":"Weighting","level":2,"score":0.6556000113487244},{"id":"https://openalex.org/C63479239","wikidata":"https://www.wikidata.org/wiki/Q7353546","display_name":"Robustness (evolution)","level":3,"score":0.5835000276565552},{"id":"https://openalex.org/C31395832","wikidata":"https://www.wikidata.org/wiki/Q1318674","display_name":"Testbed","level":2,"score":0.5791000127792358},{"id":"https://openalex.org/C79379906","wikidata":"https://www.wikidata.org/wiki/Q3174497","display_name":"Dynamical systems theory","level":2,"score":0.5368000268936157},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.4867999851703644},{"id":"https://openalex.org/C36299963","wikidata":"https://www.wikidata.org/wiki/Q1369844","display_name":"Observability","level":2,"score":0.4498000144958496},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.44190001487731934},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.42910000681877136},{"id":"https://openalex.org/C185798385","wikidata":"https://www.wikidata.org/wiki/Q1161707","display_name":"Benchmark (surveying)","level":2,"score":0.3978999853134155},{"id":"https://openalex.org/C164380108","wikidata":"https://www.wikidata.org/wiki/Q507187","display_name":"Attractor","level":2,"score":0.37860000133514404},{"id":"https://openalex.org/C2776459999","wikidata":"https://www.wikidata.org/wiki/Q2119376","display_name":"Fidelity","level":2,"score":0.3785000145435333},{"id":"https://openalex.org/C9357733","wikidata":"https://www.wikidata.org/wiki/Q6878417","display_name":"Missing data","level":2,"score":0.3774999976158142},{"id":"https://openalex.org/C125112378","wikidata":"https://www.wikidata.org/wiki/Q176640","display_name":"Randomness","level":2,"score":0.3686999976634979},{"id":"https://openalex.org/C139945424","wikidata":"https://www.wikidata.org/wiki/Q1940696","display_name":"Mean squared error","level":2,"score":0.36559998989105225},{"id":"https://openalex.org/C114275822","wikidata":"https://www.wikidata.org/wiki/Q621512","display_name":"Linear dynamical system","level":3,"score":0.35359999537467957},{"id":"https://openalex.org/C6802819","wikidata":"https://www.wikidata.org/wiki/Q1072174","display_name":"Linear system","level":2,"score":0.3528999984264374},{"id":"https://openalex.org/C61797465","wikidata":"https://www.wikidata.org/wiki/Q1188986","display_name":"Term (time)","level":2,"score":0.33160001039505005},{"id":"https://openalex.org/C119247159","wikidata":"https://www.wikidata.org/wiki/Q1366192","display_name":"System identification","level":3,"score":0.3264999985694885},{"id":"https://openalex.org/C58041806","wikidata":"https://www.wikidata.org/wiki/Q1660484","display_name":"Imputation (statistics)","level":3,"score":0.32100000977516174},{"id":"https://openalex.org/C132459708","wikidata":"https://www.wikidata.org/wiki/Q744069","display_name":"Extrapolation","level":2,"score":0.3192000091075897},{"id":"https://openalex.org/C19619285","wikidata":"https://www.wikidata.org/wiki/Q196372","display_name":"Observational error","level":2,"score":0.3167000114917755},{"id":"https://openalex.org/C85847156","wikidata":"https://www.wikidata.org/wiki/Q59015987","display_name":"Verifiable secret sharing","level":3,"score":0.3077000081539154},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.3059999942779541},{"id":"https://openalex.org/C157286648","wikidata":"https://www.wikidata.org/wiki/Q846780","display_name":"Kalman filter","level":2,"score":0.29420000314712524},{"id":"https://openalex.org/C83546350","wikidata":"https://www.wikidata.org/wiki/Q1139051","display_name":"Regression","level":2,"score":0.289900004863739},{"id":"https://openalex.org/C197115733","wikidata":"https://www.wikidata.org/wiki/Q1003136","display_name":"Forcing (mathematics)","level":2,"score":0.28600001335144043},{"id":"https://openalex.org/C163175372","wikidata":"https://www.wikidata.org/wiki/Q3339222","display_name":"Linear model","level":2,"score":0.2824999988079071},{"id":"https://openalex.org/C5297727","wikidata":"https://www.wikidata.org/wiki/Q786970","display_name":"Autocorrelation","level":2,"score":0.2727999985218048},{"id":"https://openalex.org/C150921843","wikidata":"https://www.wikidata.org/wiki/Q1170431","display_name":"Resampling","level":2,"score":0.2720000147819519},{"id":"https://openalex.org/C28826006","wikidata":"https://www.wikidata.org/wiki/Q33521","display_name":"Applied mathematics","level":1,"score":0.26579999923706055},{"id":"https://openalex.org/C2780799671","wikidata":"https://www.wikidata.org/wiki/Q17087362","display_name":"Transient (computer programming)","level":2,"score":0.2651999890804291},{"id":"https://openalex.org/C124101348","wikidata":"https://www.wikidata.org/wiki/Q172491","display_name":"Data mining","level":1,"score":0.26460000872612},{"id":"https://openalex.org/C47446073","wikidata":"https://www.wikidata.org/wiki/Q5165890","display_name":"Control theory (sociology)","level":3,"score":0.26030001044273376},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.2508000135421753}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.48550/arxiv.2602.15637","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2602.15637","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":null,"raw_source_name":null,"raw_type":"Preprint"}],"best_oa_location":{"id":"doi:10.48550/arxiv.2602.15637","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.2602.15637","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Preprint"},"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":0,"referenced_works":[],"related_works":[],"abstract_inverted_index":{"Time-series":[0],"imputation":[1],"benchmarks":[2],"employ":[3],"uniform":[4],"random":[5],"masking":[6],"and":[7,61,71,171,192,206],"shape-agnostic":[8],"metrics":[9],"(MSE,":[10],"RMSE),":[11],"implicitly":[12],"weighting":[13],"evaluation":[14,68],"by":[15],"regime":[16,52,95],"prevalence.":[17],"In":[18],"systems":[19],"with":[20,102],"a":[21,36,63,80,145],"dominant":[22],"attractor":[23],"--":[24,33,82,97,144],"homeostatic":[25],"physiology,":[26],"nominal":[27],"industrial":[28],"operation,":[29],"stable":[30,112],"network":[31],"traffic":[32],"this":[34,59],"creates":[35],"systematic":[37],"\\emph{Stationarity":[38],"Bias}:":[39],"simple":[40],"methods":[41,133],"appear":[42],"superior":[43],"because":[44],"the":[45,49,149,157],"benchmark":[46],"predominantly":[47],"samples":[48],"easy,":[50],"low-entropy":[51,122],"where":[53,152,219],"they":[54],"trivially":[55],"succeed.":[56],"We":[57,183],"formalize":[58],"bias":[60],"propose":[62],"\\emph{Stratified":[64],"Stress-Test}":[65],"that":[66,92,115],"partitions":[67],"into":[69],"Stationary":[70],"Transient":[72],"regimes.":[73],"Using":[74],"Continuous":[75],"Glucose":[76],"Monitoring":[77],"(CGM)":[78],"as":[79],"testbed":[81],"chosen":[83],"for":[84,179],"its":[85],"rigorous":[86],"ground-truth":[87],"forcing":[88],"functions":[89],"(meals,":[90],"insulin)":[91],"enable":[93],"precise":[94],"identification":[96],"we":[98,147],"establish":[99],"three":[100],"findings":[101],"broad":[103],"implications:(i)~Stationary":[104],"Efficiency:":[105],"Linear":[106],"interpolation":[107],"achieves":[108],"state-of-the-art":[109],"reconstruction":[110],"during":[111,174],"intervals,":[113],"confirming":[114],"complex":[116],"architectures":[117],"are":[118],"computationally":[119],"wasteful":[120],"in":[121],"regimes.(ii)~Transient":[123],"Fidelity:":[124],"During":[125],"critical":[126,223],"transients":[127],"(post-prandial":[128],"peaks,":[129],"hypoglycemic":[130],"events),":[131],"linear":[132],"exhibit":[134],"drastically":[135],"degraded":[136],"morphological":[137,172],"fidelity":[138],"(DTW),":[139],"disproportionate":[140],"to":[141,215],"their":[142],"RMSE":[143],"phenomenon":[146],"term":[148],"\\emph{RMSE":[150],"Mirage},":[151],"low":[153],"pointwise":[154,169],"error":[155],"masks":[156],"destruction":[158],"of":[159],"signal":[160],"shape.(iii)~Regime-Conditional":[161],"Model":[162],"Selection:":[163],"Deep":[164],"learning":[165],"models":[166,200],"preserve":[167],"both":[168],"accuracy":[170],"integrity":[173],"transients,":[175],"making":[176],"them":[177,194],"essential":[178],"safety-critical":[180],"downstream":[181],"tasks.":[182],"further":[184],"derive":[185],"empirical":[186],"missingness":[187],"distributions":[188],"from":[189,201],"clinical":[190],"trials":[191],"impose":[193],"on":[195],"complete":[196],"training":[197],"data,":[198],"preventing":[199],"exploiting":[202],"unrealistically":[203],"clean":[204],"observations":[205],"encouraging":[207],"robustness":[208],"under":[209],"real-world":[210],"missingness.":[211],"This":[212],"framework":[213],"generalizes":[214],"any":[216],"regulated":[217],"system":[218],"routine":[220],"stationarity":[221],"dominates":[222],"transients.":[224]},"counts_by_year":[],"updated_date":"2026-07-28T07:46:37.118299","created_date":"2026-02-19T00:00:00"}