Models for capacitated lot-sizing problem with backlogging,setup carryover and crossover

Setup operations are significant in some production environments. It is mandatory that their production plans consider some features, as setup state conservation across periods through setup carryover and crossover. The modelling of setup crossover allows more flexible decisions and is essential for problems with long setup times. This paper proposes two models for the capacitated lot-sizing problem with backlogging and setup carryover and crossover. The first is in line with other models from the literature, whereas the second considers a disaggregated setup variable, which tracks the starting and completion times of the setup operation. This innovative approach permits a more compact formulation. Computational results show that the proposed models have outperformed other state-of-the-art formulation.     

Stability and convergence of the spectral Lagrange-Galerkin method for mixed periodic/non-periodic convection-dominated diffusion problems

We present a convergence analysis of the spectral Lagrange-Galerkinmethod for mixed periodic/non-periodic convection-diffusionproblems. The scheme is unconditionally stable, independentof the diffusion coefficient, even in the case when numericalquadrature is used. The theoretical predictions are illustratedby a series of numerical experiments. For the periodic case,our results present a significant improvement on those givenby Süli & Ware (1991) SIAM J. Numer.Anal.28, 423-445).     

Investigation of neutrino oscillations in the T2k long-baseline accelerator experiment

High-sensitivity searches for transitions of muon neutrinos to electron neutrinos are the main task of the T2K (Tokai-to-Kamioka) second-generation long-baseline accelerator neutrino experiment. The present article is devoted to describing basic principles of T2K, surveying experimental apparatuses that it includes, and considering in detail the muon-range detector (SMRD) designed and manufactured by a group of physicists from the Institute of Nuclear Research (Russian Academy of Sciences, Moscow). The results of the first measurements with a neutrino beam are presented, and plans for the near future are discussed.     

Efficient evaluation of short-range Hartree-Fock exchange in large molecules and periodic systems

We present an efficient algorithm for the evaluation of short-range Hartree-Fock exchange energies and geometry gradients in Gaussian basis sets. Our method uses a hierarchy of screening levels to eliminate negligible two-electron integrals whose evaluation is the fundamental computational bottleneck of the procedure. By applying our screening technique to the Heyd-Scuseria-Ernzerhof [J. Chem. Phys. 118, 8207 (2003)] short-range Coulomb hybrid density functional, we achieve a computational efficiency comparable with that of standard nonhybrid density functional calculations.     

Resolution of the identity atomic orbital Laplace transformed second order Møller-Plesset theory for nonconducting periodic systems

An improvement in performance of the atomic orbital Laplace transformed second-order M?ller-Plesset (AO-LT-MP2) method for periodic systems is reported using the resolution of identity (RI) technique. Transformation of the two-electron integrals constitutes the main computational bottleneck of the AO-LT-MP2 method. A substitution of regular four-center integrals by their three center counterparts in the RI approximation naturally reduces the computational cost of the integral transformation step. The RI divergence problem in the presence of periodic boundary conditions is solved in our implementation by restricting the fitting domain. Accuracy and computational efficiency of the RI-AO-LT-MP2 approach are assessed on a set of one-dimensional test systems: trans-polyacetylene and anti-transoid polymethineimine.     

Generation of nonlinearity to increase the variety of systems with dynamic and static instability

A research axiom operating with notions of a conditional flux, a modifier, and an accumulator is put forward. The interpretation of the dynamic system (DS) including the author’s concepts of the DS “form” and isodynamism is used. As a result, a method of functional DS transformation under an external action is suggested given that the system structure remains unchanged. This gives the researchers and developers principles for the creation of a new DS. A computer experiment confirms the idea of nonlinearity control.     

Why are time-dependent density functional theory excitations in solids equal to band structure energy gaps for semilocal functionals, and how does nonlocal Hartree-Fock-type exchange introduce excitonic effects?

We examine the time-dependent density functional theory (TD-DFT) equations for calculating excitation energies in solids with Gaussian orbitals and analytically show that for semilocal functionals, their lowest eigenvalue collapses to the minimum band orbital energy difference. With the introduction of nonlocal Hartree-Fock-type exchange (as in hybrid functionals), this result is no longer valid, and the lowest TD-DFT eigenvalue reflects the appearance of excitonic effects. Previously reported "charge-transfer" problems with semilocal TD-DFT excitations in molecules can be deduced from our analysis by taking the limit to infinite lattice constant.     

Synthesis of chloro(organo)silylmethyl-o-carboranes from organochlorosilanes and bromomagnesiummethyl-o-carboranes

Russian Chemical Bulletin - An efficient method for the synthesis of 1-chloro(dimethyl)silylmethyl-o-carborane, 1-dichloro(methyl)silylmethyl-o-carborane, 1-trichlorosilylmethyl-o-carborane, and...