Complex Hyperbolic Surfaces of Abelian Type

2000 Mathematics Subject Classification: 11G15, 11G18, 14H52, 14J25, 32L07.

Factorizations of some Groups of Lie Type of Lie Rank 4

Еленка Генчева, Цанко Генчев В настоящата работа се разглеждат крайни прости групи G , които могат да се представят като произведение на две свои собствени неабелеви прости подгрупи A и B. Всяко такова представяне G = AB е прието да се нарича факторизация на G, а тъй като множителите A и B са избрани да бъдат прости подгрупи на G, то разглежданите факторизации са известни още като прости факторизации на G. Тук се предполага, че G е проста група от лиев тип и лиев ранг 4 над крайно поле GF (q). Ключови думи: крайни прости групи, групи от лиев тип, факторизации на групи.

Principles of Extremum and Application to some Problems of Analysis

AMS subject classification: 41A17, 41A50, 49Kxx, 90C25.

On some Extremal Problems of Landau

2000 Mathematics Subject Classification: Primary: 42A05. Secondary: 42A82, 11N05.

Weighted Approximation by a Class of Bernstein-Type Operators

AMS classification: 41A36, 41A10, 41A25, 41Al7.

Luminescence of delafossite-type CuAlO2 fibers with Eu substitution for Al cations

CuAlO2 has been examined as a potential luminescent material by substituting Eu for Al cations in the delafossite structure. CuAlO2:Eu3+ nanofibers have been prepared via electrospinning for the ease of mitigating synthesis requirements and for future optoelectronics and emerging applications. Single-phase CuAlO2 fibers could be obtained at a temperature of 1100 °C in air. The Eu was successfully doped in the delafossite structure and two strong emission bands at ~405 and 610 nm were observed in the photoluminescence spectra. These bands are due to the intrinsic near-band-edge transition of CuAlO2 and the f-f transition of the Eu3+ activator, respectively. Further electrical characterization indicated that these fibers exhibit semiconducting behavior and the introduction of Eu could act as band-edge modifiers, thus changing the thermal activation energies. In light of this study, CuAlO2:Eu3+ fibers with both strong photoluminescence and p-type conductivity could be produced by tailoring the rare earth doping concentrations.

A method for solving LSM problems of small size in the AHP

The Analytic Hierarchy Process (AHP) is one of the most popular methods used in Multi-Attribute Decision Making. It provides with ratio-scale measurements of the prioirities of elements on the various leveles of a hierarchy. These priorities are obtained through the pairwise comparisons of elements on one level with reference to each element on the immediate higher level. The Eigenvector Method (EM) and some distance minimizing methods such as the Least Squares Method (LSM), Logarithmic Least Squares Method (LLSM), Weighted Least Squares Method (WLSM) and Chi Squares Method (X2M) are of the tools for computing the priorities of the alternatives. This paper studies a method for generating all the solutions of the LSM problems for 3 × 3 matrices. We observe non-uniqueness and rank reversals by presenting numerical results.

Versenyképesség haloptikával – Helyi gazdaságfejlesztési problémák fejlődő városokban = Competitiveness at short range - Local problems of economic development in medium-sized towns

The aim of our research in the first half of 2011 was to find out what were the administrative, regulative and other problems that were specific obstacles to local economic development and what best practices can be found in local economies. During our research we carried out interviews with leaders and local professionals in five medium size towns of Hungary. We stated that the most obstructive factors were the imperfection of vocational training, the excessively bureaucratic administrative proceedings (supplying of data, acquisition of authority permits, the attitude of the authorities, etc.) and the system of application and finding sources of funds. We think that the most innovative solutions are the good examples of the institutionalized co-operation between local governments and local businesses. We've come to the conclusion that there is a need for reducing administrative burdens for the sake of local economic development.

Minsk and Budapest, the two capital cities. Selected studies of post-socialist urban geography and ecological problems of urban areas

The official cooperation between the Hungarian and the Belarusian geography began to be outlined in a sunny afternoon of June 2010 in the Minsk building of the Geographic Faculty of the Belarusian State University, four years ago. Then we reviewed the potential frames of cooperation with Professor Ekaterina Antipova. It was supported by the academican Károly Kocsis, member of the Hungarian Academy of Sciences, director of the Geographical Research Institute, and we could also win the support of the dean Ivan Pirozhnik and the academician Vladimir Loginov from the Belarusian State University and the National Academy of Sciences of Belarus, respectively. This informal cooperation became official in the autumn of 2010 in the frame of the Academic Mobility Agreement Project between the Hungarian and the Belarusian academies of sciences. Since then several publications have appeared about Hungary and Belarus in the geographic journals of both countries, however, this is the first, long awaited, significant common publication. Besides the project-based co-operations like e. g. the EastMig (www.eastmig.mtafki.hu) and the ReSEP-CEE (www.mtafki.hu/ReSEP_CEE_Be.html) supported by the Visegrad Fund, a vivid student exchange program was also launched from the autumn of 2010 between the Geographic Research Institute of the Hungarian Academy of Sciences, and the Geographic Faculty of the Belarusian State University with the scholarship program of the Visegrad Fund. Later the Department of Economic Geography of the Corvinus University of Budapest, headed by István Tózsa became also an active partner of the cooperation. The publishing expenses of this book are also fully financed by the Department of Economic Geography.

A Comparison of Anchor-Item Designs for the Concurrent Calibration of Large Banks of Likert-Type Items

Current interest in measuring quality of life is generating interest in the construction of computerized adaptive tests (CATs) with Likert-type items. Calibration of an item bank for use in CAT requires collecting responses to a large number of candidate items. However, the number is usually too large to administer to each subject in the calibration sample. The concurrent anchor-item design solves this problem by splitting the items into separate subtests, with some common items across subtests; then administering each subtest to a different sample; and finally running estimation algorithms once on the aggregated data array, from which a substantial number of responses are then missing. Although the use of anchor-item designs is widespread, the consequences of several configuration decisions on the accuracy of parameter estimates have never been studied in the polytomous case. The present study addresses this question by simulation, comparing the outcomes of several alternatives on the configuration of the anchor-item design. The factors defining variants of the anchor-item design are (a) subtest size, (b) balance of common and unique items per subtest, (c) characteristics of the common items, and (d) criteria for the distribution of unique items across subtests. The results of this study indicate that maximizing accuracy in item parameter recovery requires subtests of the largest possible number of items and the smallest possible number of common items; the characteristics of the common items and the criterion for distribution of unique items do not affect accuracy.

Type of actors, objects of exchange, type of original transactions in the coverage of corruption

In the following analysis we deal with only specific corruption cases within our seven-country sample for content analysis (France, Hungary, Italy, Latvia, Romania, Slovakia, and the UK). Only 5,212 relevant articles dealt with such cases within the total sample (12,742). We focus here on providing a descriptive comparative analysis of the actors, types of transactions and country specifics. The second part of the analysis describes the actors involved in the corrupt transactions, while in the third section we deal with the object of exchange in corrupt transactions. The fourth section focuses on the type of transaction which is linked to the corruption. Finally, a summary of the results of our preliminary findings is provided.

Giant enhancement of n-type carrier mobility in highly strained germanium nanostructures

First-principles electronic structure methods are used to predict the rate of n-type carrier scattering due to phonons in highly-strained Ge. We show that strains achievable in nanoscale structures, where Ge becomes a direct bandgap semiconductor, cause the phonon-limited mobility to be enhanced by hundreds of times that of unstrained Ge, and over a thousand times that of Si. This makes highly tensile strained Ge a most promising material for the construction of channels in CMOS devices, as well as for Si-based photonic applications. Biaxial (001) strain achieves mobility enhancements of 100 to 1000 with strains over 2%. Low temperature mobility can be increased by even larger factors. Second order terms in the deformation potential of the Gamma valley are found to be important in this mobility enhancement. Although they are modified by shifts in the conduction band valleys, which are caused by carrier quantum confinement, these mobility enhancements persist in strained nanostructures down to sizes of 20 nm.

First-principles calculation of P-type alloy scattering in Si1-xGex

The p-type carrier scattering rate due to alloy disorder in Si1-xGex alloys is obtained from first principles. The required alloy scattering matrix elements are calculated from the energy splitting of the valence bands, which arise when one average host atom is replaced by a Ge or Si atom in supercells containing up to 128 atoms. Alloy scattering within the valence bands is found to be characterized by a single scattering parameter. The hole mobility is calculated from the scattering rate using the Boltzmann transport equation in the relaxation time approximation. The results are in good agreement with experiments on bulk, unstrained alloys..