Many economic data sets are contaminated by the mismeasured variables. The problem of measurement errors is one of the most fundamental problems in empirical economics. The presence of measurement errors causes biased and inconsistent parameter estimates and leads to erroneous conclusions to various degrees in economic analysis. Techniques for addressing measurement error problems can be classi...

A new heterodyne nano-displacement with error reduction is presented. The main errors affecting the displacement accuracy of the nano-displacement measurement system including intermodulation distortion error, cross-talk error, cross-polarization error and phase detection error are calculated. In the designed system, a He-Ne laser having three-longitudinal-mode is considered as the stabiliz...

Medidas analíticas modernas são comumente apresentadas na forma de vetores (e.g., espectros) ou estruturas de dados de ordem maior como matrizes, que são normalmente sujeitas a estratégias de análise multivariada de dados para a extração de informações. Um aspecto dessas medidas que normalmente é pouco compreendida é a natureza subentendida dos erros, e como eles afetam a obtenção da informação...

Steve Hickey, Hilary Roberts The Cochrane review by Douglas et al. [1], which is referenced in the Best Practice article by Douglas and Hemilä [2], covers 60 years of research into vitamin C and the common cold. However, the review omits pharmacokinetic data that invalidate the conclusion that vitamin C is ineffective. This conclusion is not derivable from the data presented. The dual-phase pha...

The value of research in any topic area turns on its validity. Patient safety research has revealed--or, at least, given renewed urgency to--a raft of methodological issues. The meaning and thus the value of empirical research in this field is contingent on getting the methodology right. The need for good methods for the measurement of error is necessary whenever an inference is intended and, s...

Two radiation measurement technologies for estimating and lowering the occurrence rate of “soft errors” are introduced. Radiation such as fast neutrons (generated by cosmic rays) and α-rays (generated by the impurities in materials composing LSIs) cause incorrect operations—known as soft errors—in computer systems. Since soft errors undermine the reliability of mission-critical products such as...

Definitions of the concepts of bias and recovery are discussed and approaches to dealing with them described. The Guide To Uncertainty in Measurement (GUM) recommends correction for all significant systematic effects, but it is also possible to expand measurement uncertainty to take account of uncorrected bias. Run, laboratory and method bias can be defined as components of the bias of a partic...

OBJECTIVE To quantify the errors associated with manual measurement of QT intervals and to determine the source of the errors. DESIGN A randomised study of QT measurement by four cardiologists of electrocardiograms plotted on paper in presentations with different noise levels, paper speeds, amplifier gains, and with and without a second QRST complex to indicate the RR interval. SUBJECTS Fou...

It is common to model the random errors in a classical measurement by the normal (Gaussian) distribution, because of the central limit theorem. In the quantum theory, the analogous hypothesis is that the matrix elements of the errors of an observable are distributed normally. We obtain the probability distribution this implies for the outcome of a measurement, exactly for the case of traceless ...