We extend the optimal symmetric group sequential tests of Eales & Jennison (1992) to the broader class of asymmetric designs. Two forms of asymmetry are considered, involving unequal type I and type II error rates and different emphases on expected sample sizes at the null and alternative hypotheses. We discuss the properties of our optimal designs and use them to assess the efficiency of the f...

Traditionally, the earthmoving operations have been developed based on the minimum cost per production criterion. Nowadays, due to the negative impacts of the emissions on the environment, there is an increasing public awareness to reduce the emissions from the earthmoving operations. Different management strategies can be employed to reduce emissions, amongst other things, which can also resul...

Three-stage t-tests of separated one-sided hypotheses are derived, extending Lorden’s optimal three-stage tests for the one-dimensional exponential family by using Lai and Zhang’s generalization of Schwarz’s optimal fully-sequential tests to the multiparameter exponential family. The resulting three-stage t-tests are shown to be asymptotically optimal, achieving the same average sample size as ...

By shouldering the burden of a big chunk of global production, and giving Shelter to half of the world’s population, currently cities play an important role in national economies. Benefits of agglomeration in cities have played a major role in the process of economic development of different countries, however, the expansion of urbanization has produced some problems including environmental and...

In this paper, we present a method for overlapping communications on parallel computers for pipelined algorithms. We rst introduce a general theoretical model which leads to a generic computation scheme for the optimal packet size. Then, we use the OPIUM 3 library, which provides an easy-to-use and eecient way to compute, in the general case, this optimal packet size, on the column LU factoriza...

Optimal firm size and patterns of returns to scale among the local exchange companies in the U.S. telecommunications industry are estimated for the years: 1975, 1978, 1981, 1984, 1987 and 1990. The independent companies display increasing returns to scale, while the Baby Bells display constant or decreasing returns to scale. The independent companies operate at a scale smaller than optimal size...