Self-study guide to developing English linguistic competences for students of Computer Sciences

Методичні вказівки призначені для самостійної роботи студентів ІТ спеціальностей над опануванням фахової термінології та мають на меті допомогти студентам І та ІІ курсів самостійно працювати над розширенням словникового запасу, розвитком вмінь здобування інформації з англомовних текстових джерел

Алгоритм построения прогнозируемой площади пожара в тактической модели

The miniaturization of components in the field of life science, consumer electronics and micro-electro-mechanical systems (MEMS) is becoming a part of our everyday life. As the manufacturing of these components demands in many cases the machining by micromilling with cutting tools down to 100 µm diameter, highly dynamic machine tools are needed to machine the more and more complex freeform surfaces at optimal process parameters. The paper describes the development of a highly dynamic milling machine which is equipped with linear direct drives in all axes with integrated impulse decoupling units to allow high dynamics and especially high jerks at low impact on the machine structure. Additionally the development of a metrology frame is detailed which can be used to characterize the dyna mic tool path of machine tools to optimize its dynamic setup and to increase the work piece precision at minimized machining time

ВНЕСОК КРАЄЗНАВЦЯ В.В. БІНКЕВИЧА У ДОСЛІДЖЕННЯ АРХЕОЛОГІЧНИХ ПАМ’ЯТОК НАДПОРІЖЖЯ

Розглянуто творчий шлях визначного дніпропетровського краєзнавця Володимира Васильовича Бінкевича.The author considers creative way of the famous dnipropetrovsk student of local lore Volodimir Vasil’ovich Binkevich

Decay Modes of Intersecting Fluxbranes

Just as the single fluxbrane is quantum mechanically unstable to the nucleation of a locally charged spherical brane, so intersecting fluxbranes are unstable to various decay modes. Each individual element of the intersection can decay via the nucleation of a spherical brane, but uncharged spheres can also be nucleated in the region of intersection. For special values of the fluxes, however, intersecting fluxbranes are supersymmetric, and so are expected to be stable. We explicitly consider the instanton describing the decay modes of the two--element intersection (an F5-brane in the string theory context), and show that in dimensions greater than four the action for the decay mode of the supersymmetric intersection diverges. This observation allows us to show that stable intersecting fluxbranes should also exist in type 0A string theory.Comment: 19 pages, 6 figures. References adde

The polarization of F1 strings into D2 branes: "Aut Caesar aut nihil"

We give matrix and supergravity descriptions of type IIA F-strings polarizing into cylindrical D2 branes. When a RR four-form field strength F_4 is turned on in a supersymmetric fashion (with 4 supercharges), a complete analysis of the solutions reveals the existence of a moduli space of F1 -> D2 polarizations (Caesar) for some fractional strengths of the perturbation, and of no polarization whatsoever (nihil) for all other strengths of the perturbation. This is a very intriguing phenomenon, whose physical implications we can only speculate about. In the matrix description of the polarization we use the Non-Abelian Born-Infeld action in an extreme regime, where the commutators of the fields are much larger than 1. The validity of the results we obtain, provides a direct confirmation of this action, although is does not confirm or disprove the symmetrized trace prescription.Comment: 14 page

Rotating charged Black Holes in Einstein-Born-Infeld theories and their ADM mass

In this work, the solution of the Einstein equations for a slowly rotating black hole with Born-Infeld charge is obtained. Geometrical properties and horizons of this solution are analyzed. The conditions when the ADM mass (as in the nonlinear static cases) and the ADM angular momentum of the system have been modified by the non linear electromagnetic field of the black hole, are considered.Comment: Final version and figures in journal. References and comments adde

Non-Abelian Giant Gravitons

We argue that the giant graviton configurations known from the literature have a complementary, microscopical description in terms of multiple gravitational waves undergoing a dielectric (or magnetic moment) effect. We present a non-Abelian effective action for these gravitational waves with dielectric couplings and show that stable dielectric solutions exist. These solutions agree in the large $N$ limit with the giant graviton configurations in the literature.Comment: 8 pages. Contribution to the proceedings of the RTN workshop in Leuven, Belgium, September 200

More D-branes in plane wave spacetime

We present classical solutions of Dp-branes $(p \ge 5)$ in plane wave spacetime with nonconstant R-R 3-form flux. We also show the existence of a system of D3-branes in this background. We further analyze the supersymmetric properties of these branes by solving type II Killing spinor equations explicitly.Comment: 13 pages, references added, to appear in Phys. Letts.

Primordial magnetic field and spectral distortion of cosmic background radiation

The role played by a primordial magnetic field during the pre-recombination epoch is analysed through the cyclotron radiation (due to the free electrons) it might produce in the primordial plasma. We discuss the constraint implied by the measurement or lack thereof COBE on this primordial field.Comment: to appear in International Journal of Mod. Phy

Supertube domain-walls and elimination of closed time-like curves in string theory

We show that some novel physics of supertubes removes closed time-like curves from many supersymmetric spaces which naively suffer from this problem. The main claim is that supertubes naturally form domain-walls, so while analytical continuation of the metric would lead to closed time-like curves, across the domain-wall the metric is non-differentiable, and the closed time-like curves are eliminated. In the examples we study the metric inside the domain-wall is always of the G\"odel type, while outside the shell it looks like a localized rotating object, often a rotating black hole. Thus this mechanism prevents the appearance of closed time-like curves behind the horizons of certain rotating black holes.Comment: 22 pages, JHEP3 class. V2: Some corrections and clariffications, references added. V3: more corrections to formulas, results unchanged. V4: minor typos, as published in PR