Ludwig D A, Krock L P
University of North Carolina, Department of Mathematics and Statistics, Greensboro.
Aviat Space Environ Med. 1991 Mar;62(3):261-5.
Most acceleration studies estimate a subject's G-level tolerance by taking only one determination (test) for a given condition. The purpose of this study was to examine the error structure and reliability of an individual's acceleration tolerance and to provide design considerations for future experimentation. A hierarchical (nested) design was used to estimate the sources of variation in measuring G-level tolerance. Six males rode relaxed in the USAF School of Aerospace Medicine human-use centrifuge and were exposed to a 0.1 G/s onset rate profile until greyout. Each subject was tested on three randomly selected days with three repeated determinations within a day. This design allowed for an estimate of both day-to-day and measurement error within a testing session. A single +Gz tolerance determination was found to be moderately unreliable (reliability coefficient = 0.74). Under the best of circumstances a subject's G-level tolerance cannot be estimated with any more accuracy than about +/- 0.3 G with 95% confidence. This degree of accuracy can only be obtained with multiple measurements.
大多数加速度研究通过对给定条件仅进行一次测定（测试）来估计受试者的G值耐受能力。本研究的目的是检验个体加速度耐受能力的误差结构和可靠性，并为未来的实验提供设计考量。采用分层（嵌套）设计来估计测量G值耐受能力时的变异来源。六名男性在美国空军航空航天医学院的人体离心机中放松乘坐，并暴露于0.1G/s的起始速率曲线下，直至出现灰视。每个受试者在三个随机选择的日子进行测试，每天重复测定三次。这种设计能够估计出每日误差和测试期间的测量误差。发现单次 +Gz 耐受能力测定的可靠性中等（可靠性系数 = 0.74）。在最佳情况下，受试者的G值耐受能力估计精度在95%置信度下不会超过约±0.3G。只有通过多次测量才能获得这种精度。
