A Note on Queueing Systems Exposed to Disasters

We discuss queueing systems subject to total disasters. If the time intervals between successive disasters are i.i.d. random variables independent of arrival and service process and arrivals form a Poisson process, then the transient and the asymptotic analysis of such models may be based on Feller's Second Renewal Theorem. Several examples are given: the limiting behavior of M/G/1 in case of exponential disasters and its special cases M/M/1, M/M/1/K and M/M/infinity. (author´s abstract)Series: Research Report Series / Department of Statistics and Mathematic

Non-minimal Wu-Yang monopole

We discuss new exact spherically symmetric static solutions to non-minimally extended Einstein-Yang-Mills equations. The obtained solution to the Yang-Mills subsystem is interpreted as a non-minimal Wu-Yang monopole solution. We focus on the analysis of two classes of the exact solutions to the gravitational field equations. Solutions of the first class belong to the Reissner-Nordstr{\"o}m type, i.e., they are characterized by horizons and by the singularity at the point of origin. The solutions of the second class are regular ones. The horizons and singularities of a new type, the non-minimal ones, are indicated.Comment: 10 pages, no figures, typos correcte

Non-minimal Wu-Yang wormhole

We discuss exact solutions of three-parameter non-minimal Einstein-Yang-Mills model, which describe the wormholes of a new type. These wormholes are considered to be supported by SU(2)-symmetric Yang-Mills field, non-minimally coupled to gravity, the Wu-Yang ansatz for the gauge field being used. We distinguish between regular solutions, describing traversable non-minimal Wu-Yang wormholes, and black wormholes possessing one or two event horizons. The relation between the asymptotic mass of the regular traversable Wu-Yang wormhole and its throat radius is analysed.Comment: 9 pages, 2 figures, typos corrected, 2 references adde

The Future of Institutional Repositories at Small Academic Institutions: Analysis and Insights

Institutional repositories (IRs) established at universities and academic libraries over a decade ago, large and small, have encountered challenges along the way in keeping faith with their original objective: to collect, preserve, and disseminate the intellectual output of an institution in digital form. While all institutional repositories have experienced the same obstacles relating to a lack of faculty participation, those at small universities face unique challenges. This article examines causes of low faculty contribution to IR content growth, particularly at small academic institutions. It also offers a first-hand account of building and developing an institutional repository at a small university. The article concludes by suggesting how institutional repositories at small academic institutions can thrive by focusing on classroom teaching and student experiential learning, strategic priorities of their parent institutions

How to Defeat W\"{u}thrich’s Abysmal Embarrassment Argument against Space-Time Structuralism

In his 2009 PSA Recent Ph.D. Award winning contribution to the bi-annual PSA Conference at Pittsburgh in 2008, C. Wu ̈thrich mounted an argument against struc- turalism about space-time in the context of the General Theory of Relativity (GTR), to the effect that structuralists cannot discern space-time points. An “abysmal embarrass- ment” for the structuralist, Wu ̈thrich judged. Wu ̈thrich’s characterisation of space-time structuralism is however incorrect. We demonstrate how, on the basis of a correct char- acterisation of space-time structuralism, it is possible to discern space-time points in the GTR-structures under consideration. Thus Wu ̈thrich’s argument crumbles

ON NEWTON-RAPHSON METHOD

Recent versions of the well-known Newton-Raphson method for solving algebraic equations are presented. First of these is the method given by J. H. He in 2003. He reduces the problem to solving a second degree polynomial equation. However He’s method is not applicable when this equation has complex roots. In 2008, D. Wei, J. Wu and M. Mei eliminated this deficiency, obtaining a third order polynomial equation, which has always a real root. First of the authors of present paper obtained higher order polynomial equations, which for orders 2 and 3 are reduced to equations given by He and respectively by Wei-Wu-Mei, with much improved form. In this paper, we present these methods. An example is given.newton-raphson

Industrial cluster formation in European regions. U.S. cluster templates and Austrian evidence.

The paper will be organized in the following manner. We first provide a concise review of how industrial trade clusters were developed from available I/O coefficients (see box), including how regional industrial data may be embedded within their "templates". Second, we will review the steps taken, using available industrial concordances, that permit regional data from other advanced national industrial systems to be embedded within these templates. Third, we will illustrate the results of applying the U.S. template for the motor vehicle industrial trade cluster to regions in both Austria and North Carolina over 5-10 year time periods. Finally, we will offer some speculative observations about what the results may indicate about regional cluster development in these two regions. (authors' abstract, ed. M.Putz)Series: SRE - Discussion Paper