Hypoellipticity in Gevrey classesG is characterized for a simple family of sums of squares of vector fields satisfying the bracket hypothesis, with analytic coefficients. It is shown that hypoellipticity holds if and only if s is greater than or equal to an optimal exponent that may take on any rational value.

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Due to the assumption that the best practice methods refer to each input separately instead of the whole set of inputs used by a firm, the benchmark technology as defined in the stochastic varying coefficient frontier model may be infeasible and theoretically improper whenever the maximum response coefficients are not coming from the same production unit. To overcome this problem we suggest an ...

Today, in every society the health and treatment sector are among the most important service sectors. Therefore, it is crucial that their performance be evaluated and examined. Although the researchers have proposed many different approaches to evaluate and rank the health sectors, no precise approach for evaluating and ranking have been reported up to now. Assessing the coefficient of variatio...

an experimental study has been conducted on the hydrodynamics of a stage mixer-settler to obtain an appropriate design. in this paper several tests was performed to investigate full factorial design of experiments. since each test was repeated seven times, the repeatability of the test was confirmed (p=1 bar and t=25 °c). sauter diameter was determined by photographing both the mixer and settle...

Mercurio aims at the provision of an environment for the creation of secure e-commerce services. This is motivated by the observation that pure WWW technology (as we see it at the moment) is not sufficient to realise a big variety of services provided over the Internet. The main goal is to allow the operators of e-commerce service centers and the simple vendor to develop, deploy, operate, and m...

Different definitions of the uncovered set are commonly, and often interchangeably, used in the literature. If we assume individual preferences are strict over all alternatives, these definitions are equivalent. However, if one or more voters is indifferent between alternatives these definitions may not yield the same uncovered set. This note examines how these definitions differ in a distribut...

The purpose of this study is to explore the emerging applications of E-Government, both in the United States and in the International Community. Information technology allows governments to service citizens in a more timely, effective, and cost-efficient method. E-Government implementation may meet initial citizen resistance, require cultural sensitivity, and change the way citizens and governm...

The channel choice branch of e-government studies citizens’ and businesses’ choice of channels for interacting with government, and how government organizations can integrate channels and migrate users towards the most cost-efficient channels. In spite of the valuable contributions offered no systematic overview exist of channel choice. We present a literature review of channel choice studies i...