Ensuring the relocatability of programs in the operational system DOS YeS

Specific modifications in the Disk Operational System Unified Series to insure the relocatability of programs stored permanently in the core image library is described. A self-relocating method for loading programs into the working memory with re-editing all the programs recorded in the core image library is presented. The modified linkage editor can be included in a relocation dictionary containing data about each address constant at the assembly stage at the request of the programmer. The relocation dictionary increases the dimension of the RL-phase in comparison with the dimension of this same phase when edited by the standard method, making possible the creation of multiphase program complexes. Generation and use of the modified system using Assembly language is described. An example of the use of the system is given, and limitations of the use of the relocatable programs in the modified system are outlined

Mirror symmetry for Del Pezzo surfaces: Vanishing cycles and coherent sheaves

We study homological mirror symmetry for Del Pezzo surfaces and their mirror Landau-Ginzburg models. In particular, we show that the derived category of coherent sheaves on a Del Pezzo surface X_k obtained by blowing up CP^2 at k points is equivalent to the derived category of vanishing cycles of a certain elliptic fibration W_k:M_k\to\C with k+3 singular fibers, equipped with a suitable symplectic form. Moreover, we also show that this mirror correspondence between derived categories can be extended to noncommutative deformations of X_k, and give an explicit correspondence between the deformation parameters for X_k and the cohomology class [B+i\omega]\in H^2(M_k,C).Comment: 40 pages, 9 figure

Negative high-frequency differential conductivity in semiconductor superlattices

We examine the high-frequency differential conductivity response properties of semiconductor superlattices having various miniband dispersion laws. Our analysis shows that the anharmonicity of Bloch oscillations (beyond tight-binding approximation) leads to the occurrence of negative high-frequency differential conductivity at frequency multiples of the Bloch frequency. This effect can arise even in regions of positive static differential conductivity. The influence of strong electron scattering by optic phonons is analyzed. We propose an optimal superlattice miniband dispersion law to achieve high-frequency field amplification

Ugljikovodici i klorirani ugljikovodici u zraku Splita i okolice

The content of hydrocarbons and chlorinated hydrocarbons was examined in samples of air from the greater Split area. Organic pollutants were accumulated from the air by adsorption on Polysorb-10 and desorplion with hot water vapour. Gaseous and liquid phases were analysed by gas chromatography. Hydrocarbon concentrations were within permissible limits and their effects on human health were negligible. There were marked differences between pollutant concentrations in air samples taken from the industrial zone, crossroads in the city centre and "clean" zones.Sadržaj ugljikovodika i kloriranih ugljikovodika ispitan je u uzorcima zraka iz Splita i okolice. Organski onečiščivaći akumulirani su iz zraka adsorpcijom na polimeru Polisorb-10 i desorpcijom pomoću vruće vodene pare. Plinovita i vodena faza analizirane su metodom plinske kromatografije. Koncentracije ugljikovodika bila su unutar dopuštonih granica a učinci na ljudsko zdravlje zanemarivi. Koncentracije u uzorcima zraka iz industrijske zone, raskršća u gradskom središtu i "čistih" područja uočljivo su se razlikovale

Stability of Landau-Ginzburg branes

We evaluate the ideas of Pi-stability at the Landau-Ginzburg point in moduli space of compact Calabi-Yau manifolds, using matrix factorizations to B-model the topological D-brane category. The standard requirement of unitarity at the IR fixed point is argued to lead to a notion of "R-stability" for matrix factorizations of quasi-homogeneous LG potentials. The D0-brane on the quintic at the Landau-Ginzburg point is not obviously unstable. Aiming to relate R-stability to a moduli space problem, we then study the action of the gauge group of similarity transformations on matrix factorizations. We define a naive moment map-like flow on the gauge orbits and use it to study boundary flows in several examples. Gauge transformations of non-zero degree play an interesting role for brane-antibrane annihilation. We also give a careful exposition of the grading of the Landau-Ginzburg category of B-branes, and prove an index theorem for matrix factorizations.Comment: 46 pages, LaTeX, summary adde