Time-dependent x-ray and radio observations of accreting sources give considerable insight into how jets might be produced, both in low-luminosity and high-luminosity situations. I discuss recent observations of binary x-ray sources and AGN that may have a direct bearing on jet production, and I review the theoretical efforts that have been made to understand them. While it is certainly true th...

One of the common metaphors used in textbooks on ObjectOriented programming (OOP) is to view objects in terms of the services they provide, describing them in “service oriented” terms. This opens a number of interesting questions, moving away from the simple view of OOP as an implementation tool for Web Services. First of all: if an Object is a Service, can we also say that a Service is an Obje...

We investigate properties of two-dimensional asymptotically flat black holes which arise in both string theory and in scale invariant theories of gravity. By introducing matter sources in the field equations we show how such objects can arise as the endpoint of gravitational collapse. We examine the motion of test particles outside the horizons, and show that they fall through in a finite amoun...

and in which a and 6 are constants, arises in applied mathematics in two main groups of problems. The first group, of which Mathieu's problem of the transverse vibrations of a taut elliptic membrane is typical, consists of boundary problems relative to some partial differential equation, such as the wave equation, where the boundary is an ellipse—or possibly a hyperbola. Here a fundamental requ...

An asymptotic analysis is carried out for the equations of free vibrations of a beam having varying curvature and cross-section. The effect of splitting the asymptotic limit for eigenvalues into two families is revealed and its connection with boundary conditions is discussed. The analysis of the properties of the asymptotic solution explains the phenomenon of transformation of mode shape with ...

We study strong-gravity effects on modulation of radiation emerging from accreting compact objects as a possible mechanism for flux modulation in QPOs. We construct a toy model of an oscillating torus in the slender approximation assuming thermal bremsstrahlung for the intrinsic emissivity of the medium and we compute observed (predicted) radiation signal including contribution of indirect (hig...

We are developing an advanced IaaS (Infrastructure-as-a-Service) datacenter management system that dynamically minimizes running physical servers depending on resource utilization. The management system periodically monitors the loading of a datacenter, and dynamically repacks virtual machines (VMs) into optimal physical servers. Live migration of VMs and the standby mode of physical servers ar...

“What – if” analyses of the interfacial component of nanocrystalline materials (NCM), especially at higher temperatures, were performed using a two-dimensional model. What influence would thermal excitations have on the pair distribution function, the vibrational spectra and the specific heat, over the temperature range of 30–1200 K, if the NCM would be stable over this temperature range, i.e. ...

In this paper we present how to extend object speciication logic by defaults. Thus overridable rules may be used in speciications which deal not only with object states, but also with dynamic object behaviour like enabling / occurrence of actions and temporal evolution. Defaults are particularly useful to formalize implicit negation, the \minimal change" semantics of actions, inheritance betwee...

Active commuting between home and place of work or study is often cited as an interesting source of physical activity in a public health perspective. However, knowledge about these behaviors is meager. This was therefore studied in adult active commuters (n = 1872) in Greater Stockholm, Sweden, a Nordic metropolitan setting. They received questionnaires and individually adjusted maps to draw th...