排序方式: 共有71条查询结果,搜索用时 15 毫秒
51.
In this paper, we propose a parallel exact method to solve bi-objective combinatorial optimization problems. This method has been inspired by the two-phase method which is a very general scheme to optimally solve bi-objective combinatorial optimization problems. Here, we first show that applying such a method to a particular problem allows improvements. Secondly, we propose a parallel model to speed up the search. Experiments have been carried out on a bi-objective permutation flowshop problem for which we also propose a new lower bound. 相似文献
52.
Pierre Haquette Barisa Talbi Jean-Luc Renaud Michèle Salmain 《Journal of organometallic chemistry》2009,694(6):937-430
2,2′-Dipyridylamine (dpa) derivatives carrying a thiol-targeted maleimide group located at the end of an alkyl substituent on the central amine were synthesized. Reaction with the organometallic precursors [(η6-arene)RuCl2]2 (arene = benzene or p-cymene) yielded the half-sandwich cationic complexes [(η6-arene)Ru(dpa)Cl]+ where the dipyridylamine derivatives were coordinated as bidentate N,N donor ligands. Enzymatic studies showed that these derivatives were able to inactivate the cysteine endoproteinase papain by S-alkylation of the cysteine active site. 相似文献
53.
The bin packing problem with conflicts (BPC) consists of minimizing the number of bins used to pack a set of items, where some items cannot be packed together in the same bin due to compatibility restrictions. The concepts of dual-feasible functions (DFF) and data-dependent dual-feasible functions (DDFF) have been used in the literature to improve the resolution of several cutting and packing problems. In this paper, we propose a general framework for deriving new DDFF as well as a new concept of generalized data-dependent dual-feasible functions (GDDFF), a conflict generalization of DDFF. The GDDFF take into account the structure of the conflict graph using the techniques of graph triangulation and tree-decomposition. Then we show how these techniques can be used in order to improve the existing lower bounds. 相似文献
54.
F. Talbi M. Bouledroua K. Alioua 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,50(2):141-151
This theoretical work reports full quantum-mechanical analysis of the
potassium far-wing photoabsorption spectra. The accuracy of the adopted
K2 potential-energy curves and transition dipole moments is
established by computing the vibration-rotation levels and the radiative
lifetimes of the excited molecular states and by determining the variation
law with temperature of the diffusion coefficient of atomic K(4p)
in a ground potassium gas. The pressure-broadening calculations revealed
that the photoabsorption spectra have, in the temperature range 850-3000 K, a satellite structure characterized by the presence
of three
peaks around 718.7 nm in the blue wings and 1048.1 and 1100.8 nm in the red wings. This theoretical work could in particular
point
out the occurrence in the blue wing of a satellite originating from the
bound-free B←X transitions near 731.5 nm. All
these results agree quite well with the experimentally measured values. 相似文献
55.
El-Ghazali Talbi 《Annals of Operations Research》2016,239(1):171-188
We consider the problem of creating fair course timetables in the setting of a university. The central idea is that undesirable arrangements in the course timetable, i.e., violations of soft constraints, should be distributed in a fair way among the stakeholders. We propose and discuss in detail two fair versions of the popular curriculum-based course timetabling (CB-CTT) problem, the MMF-CB-CTT problem and the JFI-CB-CTT problem, which are based on max–min fairness (MMF) and Jain’s fairness index (JFI), respectively. For solving the MMF-CB-CTT problem, we present and experimentally evaluate an optimization algorithm based on simulated annealing. We introduce three different energy difference measures and evaluate their impact on the overall algorithm performance. The proposed algorithm improves the fairness on 20 out of 32 standard instances compared to the known best timetables. The JFI-CB-CTT problem formulation focuses on the trade-off between fairness and the aggregated soft constraint violations. Here, our experimental evaluation shows that the known best solutions to 32 CB-CTT standard instances are quite fair with respect to JFI. Our experiments show that the fairness can often be improved at the cost of only a small increase in the overall amount of penalty. 相似文献
56.
Pauzat F Talbi D Miller MD DeFrees DJ Ellinger Y 《The Journal of physical chemistry》1992,96(20):7882-7886
We report the results of a theoretical study of the effect of ionization on the IR spectrum of naphthalene, using ab initio molecular orbital theory. For that purpose we determined the structures, band frequencies, and intensities of neutral and positively ionized naphthalene. The calculated frequencies and intensities allowed an assignment of the most important bands appearing in the newly reported experimental spectrum of the positive ion. Agreement with the experimental spectrum is satisfactory enough to take into consideration the unexpected and important result that ionization significantly affects the intensities of most vibrations. A possible consequence on the interpretation of the IR interstellar emission, generally supposed to originate from polycyclic aromatic hydrocarbons (PAHs), is briefly presented. 相似文献
57.
Talbi S Raffi J Aréna S Colombani J Piccerelle P Prinderre P Dolo JM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(6):1335-1341
To better understand the composite character of amino acids EPR spectra, the radiolysis and reactions which occurred after irradiation of amino acids, a comparative EPR study of a few simple amino acids has been made in order to identify qualitatively and quantitatively the different radiation-induced radicals in amino acid powders. A spin-trapping methodology has been developed and carried out on irradiated glycine, alanine and valine. 相似文献
58.
Billaud D Humbert B Thevenot L Thomas P Talbi H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(1):163-168
Electropolymerisation of indole-5-carboxylic-acid leads to the formation of electroactive polymer films. Potentiostatic deposition of the related polymer, poly(indole-5-carboxylic-acid), was carried out at a constant potential at 1.35 V versus SCE. The cyclic voltammogram of the resulting polymer in LiClO4 (0.15 mol dm(-3))/acetonitrile solution is characterized by two poorly resolved anodic and cathodic set peaks. FTIR spectroscopy was used to characterize both reduced and oxidized forms of poly(indole-5-carboxylic-acid). Assignments of the vibrational modes were proposed by comparison of the vibrational spectra of polyindole and polycyanoindole. The polymerization sites correspond to the 2 and 3 carbon positions of the pyrrole cycle. In the oxidized form of the polymer, the NH group is deprotonated while the quinoid form is present between the pyrrole rings. 相似文献
59.
Bahedi K. Addou M. Mrigal A. Ftouhi H. Talbi A. Cherrad H. Fellahi N. Bayoud S. 《Optical Review》2022,29(1):25-33
Optical Review - This paper reports the linear and nonlinear optical spectroscopic study of tungsten-doped zinc oxide thin films (ZnO:W) with various dopant concentration grown by spray pyrolysis... 相似文献
60.
Li(2p $\leftarrow$ 2s) + Na(3s) pressure broadening in the far-wing and line-core profiles
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This work reports pressure-broadening line-wing and line-core of the lithium Li (2p $\leftarrow$ 2s) resonance line perturbed by ground sodium Na (3s) atoms. In far-wing regions, the calculations are performed quantum-mechanically and are intended to examine the photoabsorption coefficients at diverse temperatures. The results show the existence of three satellites, in the blue wing near the wavelengths 470 nm and in the red wing around 862 nm and 1070 nm. For the line-core region, by adopting the simplified Baranger model, the line-width and line-shift rates are determined, and their variation law with temperature is examined. No published data were found to compare these results with. 相似文献