Copyright © 2015 Anran Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This study aimed to investigate the athletic

Thus wrote Li Yu, the Qing dramatist and playwright, who composed the

Termination and confluence properties of term rewriting systems are of fundamental importance, both from a theoretical point of view and also concerning many practical applications in computer science and mathematics. We study structural aspects of termination and confluence properties of unconditional and conditional term rewriting systems. Two types of structural aspects are considered. First we investigate single rewrite systems. In a systematic manner we analyze how restricted versions of termination and confluence relate to each other and to general termination and confluence. In particular we focus on innermost rewriting and its properties. Various structural syntactic and semantic conditions are isolated which guarantee equivalence of general termination (and confluence) and weakened versions of these properties. In a second major part we consider structural aspects of combining systems. Here we investigate modularity and preservation properties of rewrite systems under various types of combinations. We survey known results in a unifying framework and develop new approaches, in particular for ensuring the preservation of termination under various

Abstract. A virtual relation (or view) can be defined with a recursive Horn clause that is a function of one or more base relations. In general, the number of times such a Horn clause must be applied in order to retrieve all the tuples in the virtual relation depends on the contents of the base relations of the definition. However, there exist Horn clauses for which there is an upper bound on the number of applications ecessary toform the virtual relation, independent of the contents of the base relations. Considering a restricted class of recursive Horn clauses, we give necessary and sufficient conditions for members of the class to have this bound.

Natural images are complex but very structured objects and, in spite of its complexity, the sensory areas in the neocortex in mammals are able to devise learned strategies to encode them efficiently. How is this goal achieved? In this paper, we will discuss the multiscaling approach, which has been recently used to derive a redundancy reducing wavelet basis. This kind of representation can be statistically learned from the data and is optimally adapted for image coding; besides, it presents some remarkable features found in the visual pathway. We will show that the introduction of oriented wavelets is necessary to provide a complete description, which stresses the role of the wavelets as edge detectors.

Abstract. Effects of SiO2 and Fe2O3 on morphological of mullite were investigated for a special use related to mullite containing SiO2 and Fe2O3. It was concluded that, when Al2O3/SiO2 ratio near the theoretical component of mullite, the composites cannot been sintered at 1600°C. The normal morphology of mullite presents granule form with Fe2O3 addition, while takes a long column shape with the condition of excessive. SiO2 presenting. Fe2O3 can promote sintering of mullite, as well as growing in needle-like morphology.

Abstract. The axial buckling threshold force of continuous welded rail (CWR) depends on lateral stability of railway track. The conventional CWR buckling models are based on track static parameters and behavior. In this paper, a dynamic finite element model for investigating the relationship between the rail nature frequencies and the critical buckling axial force of CWR track is presented. This model consists of rails, sleepers and foundation, and covers factors of interest such as track curvature, supporting distance between adjoining sleepers. With the new dynamic model, numerical computations and analyses are performed. The correlations among the critical axial force of rail, the lateral stability and the nature frequencies of CWR track are studied. The computational results of the new dynamic model show a great agreement with the field testing results.

This paper addresses two concerns with the state of the art in network revenue management with dependent demands. The first concern is that the basic attraction model (BAM), of which the multinomial logit (MNL) model is a special case, tends to overestimate demand recapture in practice. The second concern is that the choice based deterministic linear program, currently in use to derive heuristics for the stochastic network revenue management problem, has an exponential number of variables. We introduce a generalized attraction model (GAM) that allows for partial demand dependencies ranging from the BAM to the independent demand model (IDM). We also provide an axiomatic justification for the GAM and a method to estimate its parameters. As a choice model, the GAM is of practical interest because of its flexibility to adjust productspecific recapture. Our second contribution is a new formulation called the Sales Based Linear Program (SBLP) that works for the GAM. This formulation avoids the exponential number of variables in the earlier choice-based network RM approaches, and is essentially the same size as the well known LP formulation for the IDM. The SBLP should be of interest to revenue managers because it makes choice-based network RM problems tractable to solve. In addition, the SBLP formulation yields new insights into the assortment problem that arises when capacities are infinite. Together these two contributions move forward the state of the art for network revenue management under customer choice and competition.

Multiscale domain decomposition preconditioners for anisotropic high-contrast problems

Abstract: Based on the calculation and analysis of three kinds of elastic beam’s stiffness coefficient in micro machined gyroscope, the results show: in the condition of small displacement, forces and displacement are linear relationship in clamped-clamped beam, crab-foot beam and bow beam; but as the displacement increases, the relationship between forces and displacement are obvious non-linear in clamped-clamped beam. When the displacement is three times the length of beam’s width, the bow beam’s force and displacement are linear relationship. By ANSYS crab-foot beam and bow beam’s stiffness is obtained, the simulation results and the polynomial fitting coefficient are all credible.