The reliability of a composite score is a fundamental and important topic in the social and behavioral sciences. The most commonly used reliability estimate of a composite score is coefficient a. However, under regularity conditions, the population value of coefficient a is only a lower bound on the population reliability, unless the items are essentially s-equivalent, an assumption that is lik...

Transient errors are caused by variations in feelings, moods, and mental states over time. If these errors are present, coefficient alpha is an inflated estimate of reliability. A true-score model is presented that incorporates transient errors for test-retest data, and a reliability estimate is derived. This estimate, referred to as the test-retest alpha, is less than coefficient alpha if tran...

We consider an inverse parabolic problem. We prove that the heat radiative coefficient, the initial temperature and a boundary coefficient can be simultaneously determined from the final overdetermination, provided that the heat radiative coefficient is a priori known in a small subdomain. Moreover we establish a stability estimate for this inverse problem.

July-August 2012 Imagine you fly home from vacation with your one-and-ahalf-year-old son who is traveling for free as a “lap child.” In the airport parking lot, you put him into his forwardfacing car seat, where he sits much more contentedly than he did in the rear-facing one that was mandatory until his first birthday. After he falls asleep on the way home, you transfer him to his crib without...

In this paper, we estimate the second and third Maclaurin's coefficients of certain subclass of bi-univalent functions in open unit disk defined by Caputo Fractional calculus operator and also indicate certain special cases.

We suggest a modification of the estimate for weighted L2-norm of the solution gradient of a parabolic equation via L2-norm of the free term. We found the limit upper estimate that can be achieved by transformation of the equation via adding a constant to the zero order coefficient. This upper limit estimate is used to obtain an asymptotic estimate for this weighted norm of the gradient at init...

Most statistics students know that the sample correlation coefficient R is used to estimate the population correlation coefficient ρ. If the pair (X, Y) has a bivariate normal distribution, this would not cause any trouble. However, if the marginals are nonnormal, particularly if they have high skewness and kurtosis, the estimated value from a sample may be quite different from the population c...

The Hill coefficient is commonly used to estimate the number of ligand molecules that are required to bind to a receptor to produce a functional effect. However, for a receptor with more than one ligand binding site, the Hill equation does not reflect a physically possible reaction scheme; only under the very specific condition of marked positive cooperativity does the Hill coefficient accurate...

The tire-road friction coefficient is critical to the performance of mobile robots working outdoors. However, it is difficult to measure using commercially available technology sensors. This paper presents a method of estimating the tire-road friction coefficient using a disturbance observer (DO) with compensator; the chassis speed is not needed. In this paper, the torque produced by the tire-r...