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961.
Maïtine Bergounioux 《Numerical Functional Analysis & Optimization》2013,34(5-6):515-543
The aim of this paper is to present a simple qualification condition for control elliptic problems involving constraints both on the control and the state, when there are both a distributed and a boundary control. We establish a general maximum principle and give some examples. Then we study the particular case when the control is only a boundary one and we present a Lagrangian Algorithm with a few numerical results. 相似文献
962.
On the light of a previous work and its recommendations by Matoba et al. [J. Phys. B 41, 145205 (2008)], this paper proposes to look at the mobility of ground and metastable-excited states of C+ ions moving into a helium buffer gas. The calculations, based on the three-temperature theory for solving the Boltzmann kinetic equation, are accomplished with quantum-mechanical transport cross sections at the low temperatures 4.3 and 77?K. The obtained mobility results are contrasted with the available theoretical data and experimental measurements, which show acceptable agreements. 相似文献
963.
Let (S n ) n?≥?0 be a ? d -valued random walk (d?≥?2). Using Babillot’s method (Babillot, Ann Inst Henri Poincaré, B, Tome 24(4):507–569, 1988), we give general conditions on the characteristic function of S n under which (S n ) n?≥?0 satisfies the same renewal theorem as in the independent case (i.e. the same conclusion as in the case when the increments of (S n ) n?≥?0 are assumed to be independent and identically distributed). This statement is applied to additive functionals of strongly ergodic Markov chains under the non-lattice condition and (almost) optimal moment conditions. 相似文献
964.
We present a second order image decomposition model to perform denoising and texture extraction. We look for the decomposition f=u+v+w where u is a first order term, v a second order term and w the (0 order) remainder term. For highly textured images the model gives a two-scale texture decomposition: u can be viewed as a macro-texture (larger scale) whose oscillations are not too large and w is the micro-texture (very oscillating) that may contain noise. We perform mathematical analysis of the model and give numerical examples. 相似文献
965.
Several versions of the devour digest tidy-up heuristic for unconstrained binary quadratic problems 总被引:1,自引:0,他引:1
The unconstrained binary quadratic minimization problem is known to be NP-hard and due to its computational challenge and application capability, it becomes more and more considered and involved by the recent research studies, including both exact and heuristic solution approaches. Our work is in line with what was suggested by Glover et al. (in Eur. J. Oper. Res. 137, 272–287, 2002) who proposed one pass heuristics as alternatives to the well-known Devour Digest Tidy-up procedure (DDT) of Boros et al. (in RRR 39-89, 1989). The “devour” step sets a term of the current representation to 0 or 1, and the “tidy-up” step substitutes the logical consequences derived from the “digest” step into the current quadratic function. We propose several versions of the DDT constructive heuristic based on the alternative representation of the quadratic function. We also present an efficient implementation of local search using one-flip and two-flip moves that simultaneously change the values of one or two binary variables. Computational experiments performed on instances up to 7000 variables show the efficiency of our implementation in terms of quality improvement and CPU use enhancement. 相似文献
966.
Loïc Peletan Sébastien Baguet Mohamed Torkhani Georges Jacquet-Richardet 《Nonlinear dynamics》2014,78(4):2501-2515
A quasi-periodic harmonic balance method (HBM) coupled with a pseudo arc-length continuation algorithm is developed and used for the prediction of the steady-state dynamic behaviour of rotor–stator contact problems. Quasi-periodic phenomena generally involve two incommensurable fundamental frequencies, and at present, the HBM has been adapted to deal with cases where those frequencies are known. The problem here is to improve the procedure in order to be able to deal with cases where one of the two fundamental frequencies is a priori unknown, in order to be able to reproduce self-excited phenomena such as the so-called quasi-periodic partial rub. Considering the proposed developments, the unknown fundamental frequency is automatically determined during calculation and an automatic harmonic selection procedure gives both accuracy and performance improvements. The application is based on a Jeffcott rotor model, and results obtained are compared with traditional time-marching solutions. The modified quasi-periodic HBM appears one order of magnitude faster than transient simulations while providing very accurate results. 相似文献
967.
Meccanica - In recent experimental studies an unusual time-dependent transversal behavior of the annulus fibrosus of the intervertebral disc mainly caused by the coupling between mechanics and... 相似文献
968.
Thaïs Aznar-Fernández Alessio Cimmino Marco Masi Diego Rubiales 《Natural product research》2019,33(17):2471-2479
Aphids are noxious insect pests of major crops including cereals and legumes. Particularly, pea aphid (Acyrthosiphon pisum) causes significant yield and quality loses in pea. Crop protection is largely based on noxious chemical pesticides which have prompted a renewed interest in the discovery of natural products as alternatives to synthetic insecticides. In this study different classes of natural compounds were tested in dual choice bioassays to evaluate their feeding deterrence and mortality effect on pea aphid. High feeding deterrence was produced by some of the compounds, particularly1-hexadecanol, gliotoxin, cyclopaldic acid and seiridin. On the contrary, aphid mortality was low although significant for 1-heptadecanol, cytochalasin A, 1-nonadecanol and gliotoxin. Phytotoxicity assessment showed low or imperceptible plant damaged for cytochalasin A, seiridin and 1-nonadecanol. The results obtained showed the potential of seiridin to be used as an alternative to synthetic insecticides. 相似文献
969.
Manuel Andreini Anne-Sophie Felten Hoang-Trang Tran Thien Claude Taillefumier Nadia Pellegrini-Moïse Yves Chapleur 《Tetrahedron letters》2012,53(22):2702-2705
New C-glycosylated Nβ-protected aza-β3-amino acid building blocks have been prepared from C-glycosyl aldehydes of gluco and galacto configuration by reductive amination and subsequent N-alkylation. These moieties were elaborated to β-dipeptides by elongation at the C- or the N-terminus establishing their ability to be incorporated in original glycosylated foldamers. 相似文献
970.
Dr. Julia Kaffy Dr. Corentin Berardet Dr. Loïc Mathieu Dr. Baptiste Legrand Prof. Myriam Taverna Dr. Frédéric Halgand Prof. Guillaume Van Der Rest Dr. Ludovic T. Maillard Prof. Sandrine Ongeri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(64):14612-14622
Type 2 diabetes (T2D) and Alzheimer's disease (AD) belong to the 10 deadliest diseases and are sorely lacking in effective treatments. Both pathologies are part of the degenerative disorders named amyloidoses, which involve the misfolding and the aggregation of amyloid peptides, hIAPP for T2D and Aβ1-42 for AD. While hIAPP and Aβ1-42 inhibitors have been essentially designed to target β-sheet-rich structures composing the toxic amyloid oligomers and fibrils of these peptides, the strategy aiming at trapping the non-toxic monomers in their helical native conformation has been rarely explored. We report herein the first example of helical foldamers as dual inhibitors of hIAPP and Aβ1-42 aggregation and able to preserve the monomeric species of both amyloid peptides. A foldamer composed of 4-amino(methyl)-1,3-thiazole-5-carboxylic acid (ATC) units, adopting a 9-helix structure reminiscent of 310 helix, was remarkable as demonstrated by biophysical assays combining thioflavin-T fluorescence, transmission electronic microscopy, capillary electrophoresis and mass spectrometry. 相似文献