Randomized exponential backoff is a widely deployed technique for coordinating access to a shared resource. A good backoff protocol should, arguably, satisfy three natural properties: (i) it should provide constant throughput, wasting as little time as possible; (ii) it should require few failed access attempts, minimizing the amount of wasted effort; and (iii) it should be robust, continuing t...

In recent years, a number of countries have had notable success in eliminating measles using a variety of vaccination strategies. Three WHO regions — the Americas, the Eastern Mediterranean and Europe — now have measles elimination goals. In the Americas a strategy based on supplementing high routine coverage with an initial catch-up and periodic follow-up campaigns has achieved a dramatic redu...

A fix-free code is a code, which is prefix-free and suffix-free, i.e. any codeword of a fix-free code is neither a prefix, nor a suffix of another codeword. Fix-free codes were first introduced by Schützenberg (4) and Gilbert and Moore (5), where they were called never-self-synchronizing codes. Ahlswede, Balkenhol and Khachatrian propose in (6) the conjecture that a Kraftsum of a lengths sequen...

We present a special constraint structure that possesses both reducable and chain structure. Using our constraint structure, we show that the number of required gauge fixing conditions is just equal to the number of chains and the remaining requirements follow from consistency conditions. Electrodynamics and Yang-Mills theories are discussed as examples. e-mail address: [email protected] e-m...

There are two very different approaches to accommodating the possibility of occasional identity—that is, the possibility of certain objects being identical at one time but distinct at another. One approach, advanced by André Gallois, seeks to qualify Kripke‘s notion of rigid designation, while the other, originally advanced by George Myro, seeks to qualify Leibniz’s law instead. This paper focu...

A new technique is proposed for paratubal electromyography, using a surface, non-invasive, electrode applied transnasally under nasopharyngoscope guidance. This electrode records activity of the tensor veli palatini muscle during swallowing. This technique is of interest for two reasons: endoscopic guidance offers the possibility to check correct positioning of the electrode recording at tensor...

In this paper, two methods are described, by means of which it is possible to calculate the non rigid group of molecules consisting of a number of XH3 groups attached to a rigid framework. The first method is a combination of the wreath product formalism of Balasubramanian and modern computer algebra and the second method is a computational approach by using group theory package GAP. We apply t...

Understanding of articulated shape motion plays an important role in many applications in the mechanical engineering, movie industry, graphics, and vision communities. In this paper, we study motion-based segmentation of articulated 3D shapes into rigid parts. We pose the problem as finding a group-valued map between the shapes describing the motion, forcing it to favor piecewise rigid motions....

(Nov/03 draft, forthcoming in " Pacific Philosophical Quarterly " , comments to [email protected]) abstract In this paper I argue that questions about the semantics of rigid designation are commonly and illicitly run together with distinct issues, such as questions about the metaphysics of essence and questions about the theoretical legitimacy of the possible-worlds framework. I discuss in depth t...