Two-Dimensional Cutting Problem

This paper deals with two-dimensional cutting problems. Firstly the complexity of the problem in question is estimated. Then, several known approaches for the regular (rectangular) and irregular (not necessarily rectangular) cutting problems are described. In the second part, a decision support system for cutting a rectangular sheet of material into pieces of arbitrary shapes, is presented. The system uses two earlier described methods which prefer different types of data and the user may decide which one is more suitable for the problem in question. After brief description of system data files and its manual, some experimental results are presented

Istriâ ukraїn’skogo kozactva. Narisi u dvoh tomah, pod red. V. A. Smolija – Nacional’na Akademiâ Nauk Ukraїni Instytut Istriї Ukraїni Naukovo-Doslidnij Instytut Kozactva, t. I, Kiїv 2006, ss. 799, t. II, Kiїv 2007, ss. 723

Recenzja628028

Scheduling divisible loads with time and cost constraints

In distributed computing, divisible load theory provides an important system model for allocation of data-intensive computations to processing units working in parallel. The main task is to define how a computation job should be split into parts, to which processors those parts should be allocated and in which sequence. The model is characterized by multiple parameters describing processor availability in time, transfer times of job parts to processors, their computation times and processor usage costs. The main criteria are usually the schedule length and cost minimization. In this paper, we provide the generalized formulation of the problem, combining key features of divisible load models studied in the literature, and prove its NP-hardness even for unrestricted processor availability windows. We formulate a linear program for the version of the problem with a fixed number of processors. For the case with an arbitrary number of processors, we close the gaps in the study of special cases, developing efficient algorithms for single criterion and bicriteria versions of the problem, when transfer times are negligible

Ruś – Ukraina, Białoruś w Pierwszej Rzeczypospolitej

The reviewed book is the eleventh in the series devoted to the “Culture of the First Polish Republic in dialogue with Europe. Hermeneutics of values”. This series is the aftermath of an interesting research project, whose aim is both to comprehensively present the cultural relations of the Polish-Lithuanian Commonwealth with Europe, as well as to recognize the ways and forms of mutual communication of literary, aesthetic, political and religious values. In addition, it aims to present in a broad comparative context the structure of Early Modern culture of the Polish-Lithuanian Commonwealth. Apart from the introduction, the book contains the dissertations of 11 authors originating from various scientific centers in Poland and abroad (Toruń, Białystok, Vilnius, Venice, Padua, Cracow, Poznań, Rzeszów) and representing different research specialties: philology, history, and history of art. The general and primary goal of the text it is to analyze various aspects of the Ruthenian culture of the Polish-Lithuanian Commonwealth, both in its dynamic connection with the Polish-Latin culture and the processes occurring in Eastern European Orthodoxy after the fall of the Byzantine Empire and in connection with the strengthening of the Moscow state. The key issues developed in the volume relate essentially to: values of the Ruthenian culture, some of which coincide or are identical to those recognized by Western-Polish citizens of the Commonwealth, while depend on the centuries old tradition of Eastern-Christian culture.The articles focuses on the values displayed in the Orthodox and Uniate spheres and around the polemics between them, punching with axiological arguments. The most frequently and basic problems that were raised are: determinants of identity, faith (religion), language (languages), social status, origin; the policy of rulers, the problem of ecclesiastical jurisdiction; tradition and change in culture – biblical studies, patristics, liturgy, theology; printing, translations, education; apologetics and polemics, preaching, iconography; a renewal program for the clergy that was to become the vanguard of the renewal of the entire Eastern Church; Bazylian Uniate ( Greek- Catholic) clergy: the idea of cultural integration, education, translation and publishing.The reviewed book is the eleventh in the series devoted to the “Culture of the First Polish Republic in dialogue with Europe. Hermeneutics of values”. This series is the aftermath of an interesting research project, whose aim is both to comprehensively present the cultural relations of the Polish-Lithuanian Commonwealth with Europe, as well as to recognize the ways and forms of mutual communication of literary, aesthetic, political and religious values. In addition, it aims to present in a broad comparative context the structure of Early Modern culture of the Polish-Lithuanian Commonwealth. Apart from the introduction, the book contains the dissertations of 11 authors originating from various scientific centers in Poland and abroad (Toruń, Białystok, Vilnius, Venice, Padua, Cracow, Poznań, Rzeszów) and representing different research specialties: philology, history, and history of art. The general and primary goal of the text it is to analyze various aspects of the Ruthenian culture of the Polish-Lithuanian Commonwealth, both in its dynamic connection with the Polish-Latin culture and the processes occurring in Eastern European Orthodoxy after the fall of the Byzantine Empire and in connection with the strengthening of the Moscow state. The key issues developed in the volume relate essentially to: values of the Ruthenian culture, some of which coincide or are identical to those recognized by Western-Polish citizens of the Commonwealth, while depend on the centuries old tradition of Eastern-Christian culture.The articles focuses on the values displayed in the Orthodox and Uniate spheres and around the polemics between them, punching with axiological arguments. The most frequently and basic problems that were raised are: determinants of identity, faith (religion), language (languages), social status, origin; the policy of rulers, the problem of ecclesiastical jurisdiction; tradition and change in culture – biblical studies, patristics, liturgy, theology; printing, translations, education; apologetics and polemics, preaching, iconography; a renewal program for the clergy that was to become the vanguard of the renewal of the entire Eastern Church; Bazylian Uniate ( Greek- Catholic) clergy: the idea of cultural integration, education, translation and publishing

Methods for Partitioning Data to Improve Parallel Execution Time for Sorting on Heterogeneous Clusters

International audienceThe aim of the paper is to introduce general techniques in order to optimize the parallel execution time of sorting on a distributed architectures with processors of various speeds. Such an application requires a partitioning step. For uniformly related processors (processors speeds are related by a constant factor), we develop a constant time technique for mastering processor load and execution time in an heterogeneous environment and also a technique to deal with unknown cost functions. For non uniformly related processors, we use a technique based on dynamic programming. Most of the time, the solutions are in O(p) (p is the number of processors), independent of the problem size n. Consequently, there is a small overhead regarding the problem we deal with but it is inherently limited by the knowing of time complexity of the portion of code following the partitioning

Properties of metastable alkaline-earth-metal atoms calculated using an accurate effective core potential

The first three electronically excited states in the alkaline-earth-metal atoms magnesium, calcium, and strontium comprise the (nsnp) triplet P^o_J (J=0,1,2) fine-structure manifold. All three states are metastable and are of interest for optical atomic clocks as well as for cold-collision physics. An efficient technique--based on a physically motivated potential that models the presence of the ionic core--is employed to solve the Schroedinger equation for the two-electron valence shell. In this way, radiative lifetimes, laser-induced clock shifts, and long-range interaction parameters are calculated for metastable Mg, Ca, and Sr.Comment: 13 pages, 9 table

Precision mass measurements of magnesium isotopes and implications on the validity of the Isobaric Mass Multiplet Equation

If the mass excess of neutron-deficient nuclei and their neutron-rich mirror partners are both known, it can be shown that deviations of the Isobaric Mass Multiplet Equation (IMME) in the form of a cubic term can be probed. Such a cubic term was probed by using the atomic mass of neutron-rich magnesium isotopes measured using the TITAN Penning trap and the recently measured proton-separation energies of $^{29}$Cl and $^{30}$Ar. The atomic mass of $^{27}$Mg was found to be within 1.6$\sigma$ of the value stated in the Atomic Mass Evaluation. The atomic masses of $^{28,29}$Mg were measured to be both within 1$\sigma$, while being 8 and 34 times more precise, respectively. Using the $^{29}$Mg mass excess and previous measurements of $^{29}$Cl we uncovered a cubic coefficient of $d$ = 28(7) keV, which is the largest known cubic coefficient of the IMME. This departure, however, could also be caused by experimental data with unknown systematic errors. Hence there is a need to confirm the mass excess of $^{28}$S and the one-neutron separation energy of $^{29}$Cl, which have both come from a single measurement. Finally, our results were compared to ab initio calculations from the valence-space in-medium similarity renormalization group, resulting in a good agreement.Comment: 7 pages, 3 figure

Combined CI+MBPT calculations of energy levels and transition amplitudes in Be, Mg, Ca, and Sr

Configuration interaction (CI) calculations in atoms with two valence electrons, carried out in the V(N-2) Hartree-Fock potential of the core, are corrected for core-valence interactions using many-body perturbation theory (MBPT). Two variants of the mixed CI+MBPT theory are described and applied to obtain energy levels and transition amplitudes for Be, Mg, Ca, and Sr

Calculations of collisions between cold alkaline earth atoms in a weak laser field

We calculate the light-induced collisional loss of laser-cooled and trapped magnesium atoms for detunings up to 50 atomic linewidths to the red of the ^1S_0-^1P_1 cooling transition. We evaluate loss rate coefficients due to both radiative and nonradiative state-changing mechanisms for temperatures at and below the Doppler cooling temperature. We solve the Schrodinger equation with a complex potential to represent spontaneous decay, but also give analytic models for various limits. Vibrational structure due to molecular photoassociation is present in the trap loss spectrum. Relatively broad structure due to absorption to the Mg_2 ^1Sigma_u state occurs for detunings larger than about 10 atomic linewidths. Much sharper structure, especially evident at low temperature, occurs even at smaller detunings due to of Mg_2 ^1Pi_g absorption, which is weakly allowed due to relativistic retardation corrections to the forbidden dipole transition strength. We also perform model studies for the other alkaline earth species Ca, Sr, and Ba and for Yb, and find similar qualitative behavior as for Mg.Comment: 20 pages, RevTex, 13 eps figures embedde