Given a polyhedron P by a list of inequalities we develop unbiased estimates of the number of vertices and bases of P . The estimates are based on applying tree estimation methods to the reverse search technique. The time to generate an unbiased estimate is essentially bounded by the time taken to solve a linear program on P with the simplex method. Computational experience is reported. The met...

When properly constructed, biased estimators are known to produce lower mean-square errors than unbiased estimators. A biased estimator for the problem of ultrasound time-delay estimation was recently proposed. The proposed estimator incorporates knowledge of adjacent displacement estimates into the final estimate of a displacement. This is accomplished by using adjacent estimates to create a p...

BACKGROUND Measurement error in self-reported sugars intake may be obscuring the association between sugars and cancer risk in nutritional epidemiologic studies. METHODS We used 24-hour urinary sucrose and fructose as a predictive biomarker for total sugars, to assess measurement error in self-reported sugars intake. The Nutrition and Physical Activity Assessment Study (NPAAS) is a biomarker ...

The article by Kotsopoulos and colleagues (1) shows that oophorectomy significantly decreased the incidence of breast cancer in carriers of deleterious BRCA mutations, with OR, 0.52 [95% confidence interval (CI), 0.40–0.66]. This is an important result. The authors, however, wrongly interpreted their results writing that "women who underwent surgical menopause had a 48% decrease in the risk of ...

The ability to operate effectively in a variety of contexts will be a critical attribute of deployed mobile manipulators. In general, a variety of properties, such as battery charge, workspace constraints, and the presence of dangerous obstacles, will determine the suitability of particular control policies. Some context changes will cause shifts in risk sensitivity, or tendency to seek or avoi...

In the design of randomized algorithms, we sometimes wish to estimate some quantity using an unbiased estimator. (Say we wish to estimate some quantity A, X ∼ μ is an unbiased estimator if E[X] = A.) We would like those estimations to be close to its mean w.h.p. Given some distribution μ, let Y1, · · · , Yn be i.i.d samples from μ and Y = 1 n ∑ i Yi be the empirical mean. Recall that in Problem...

Summary We investigate estimation of a normal mean matrix under the quadratic loss. Improved loss implies improved any linear combination columns First, an unbiased estimate risk is derived and Efron–Morris estimator shown to be minimax. Next, notion superharmonicity for matrix-variate functions introduced have properties analogous those usual superharmonic functions, which may independent inte...