With the imminent start of LHC experiments, development of phenomenological tools, and in particular the Monte Carlo programs and algorithms, becomes urgent. A new algorithm for the generation of a parton shower initiated by the single initial hadron beam is presented. The new algorithm is of the class of the so called “constrained MC” type algorithm (an alternative to the backward evolution MC...

Vicinal 4H and 6H-SiC(0001) surfaces have been investigated using atomic force microscopy and cross-sectional high-resolution transmission electron microscopy. We observed the characteristic self-ordering of nanofacets on any surface, regardless of polytypes and vicinal angles, after gas etching at high temperature. Two facet planes are typically revealed: (0001) and high index (112;n) that are...

Mathematical morphology is difficult to introduce for color images because in the color vector space, minimum and maximum cannot be easily defined. So, the necessary conditions, represented by the complete lattice structure induced by an ordering relation, cannot be accomplished. Instead, we can build a pseudo-morphology based on reduced color ordering. This approach uses geometrical shape inva...

‎We consider nonconvex vector optimization problems with variable ordering structures in Banach spaces‎. ‎Under certain boundedness and continuity properties we present necessary conditions for approximate solutions of these problems‎. ‎Using a generic approach to subdifferentials we derive necessary conditions for approximate minimizers and approximately minimal solutions of vector optimizatio...

We investigate the dynamic variable ordering (DVO) technique commonly used in conjunction with tree-search algorithms for solving constraint satisfaction problems. We first provide an implementation methodology for adding DVO to an arbitrary tree-search algorithm. Our methodology is applicable to a wide range of algorithms including those that maintain complicated information about the search h...

Two key issues for models of visual word recognition are the specification of an input-coding scheme and whether these input-coding schemes vary across orthographies. Here, we report two masked-priming lexical decision experiments that examined whether the ordering of the root letters plays a key role in producing transposed-letter effects in Arabic--a language characterized by non-concatenativ...

This paper addresses the classical graph drawing problem of designing an algorithm that computes an orthogonal representation with the minimum number of bends. The algorithm receives as input a 4-planar graph with a given ordering of the edges around the vertices and is allowed to change such ordering to reach the optimum. While the general problem has been shown to be NP-complete 10], polynomi...

Chemical ordering and clustering instabilities in alloys are governed by the Fourier transform of the effective pair interactions, V (k). We make use of a second-order-expansion formalism, based upon embedded-atom-method interatomic potentials, to calculate chemical and elastic contributions to V (k) for monolayer surface alloys on single-crystal substrates. It is demonstrated that the elastic ...

Line spectral frequencies (LSF) and immittance spectral frequencies (ISF) are widely used in modern speech codecs based on autoregressive model. This paper addresses LSF and ISF calculation problems. The investigation of LSF/ISF placement on adjacent quasi-stationary frames is performed. It is shown that in majority of cases the inter-frame ordering property takes place. On this basis a new app...

We consider ordering techniques to improve the performance of factored sparse approximate inverse preconditioners, concentrating on the AINV technique of M. Benzi and M. Tůma. Several practical existing unweighted orderings are considered along with a new algorithm, minimum inverse penalty (MIP), that we propose. We show how good orderings such as these can improve the speed of preconditioner c...