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101.
In this work, we present a method, called Two-Phase Pareto Local Search, to find a good approximation of the efficient set
of the biobjective traveling salesman problem. In the first phase of the method, an initial population composed of a good
approximation of the extreme supported efficient solutions is generated. We use as second phase a Pareto Local Search method
applied to each solution of the initial population. We show that using the combination of these two techniques: good initial
population generation plus Pareto Local Search gives better results than state-of-the-art algorithms. Two other points are
introduced: the notion of ideal set and a simple way to produce near-efficient solutions of multiobjective problems, by using
an efficient single-objective solver with a data perturbation technique. 相似文献
102.
Thibaut Mastrolia Dylan Possamaï 《Journal of Optimization Theory and Applications》2018,179(2):452-500
In this paper, we extend the classical Holmström and Milgrom contracting problem, by adding uncertainty on the volatility of the output for both the Agent and the Principal. We study more precisely the impact of the “Nature” playing against the Agent and the Principal, by choosing the worst possible volatility of the output. We solve the first-best and the second-best problems in this framework, and we show that optimal contracts are in a class of contracts linear with respect to the output and its quadratic variation. We also present a general modus operandi to apply our method. 相似文献
103.
Leonardo Fontoura Rafael Martinelli Marcus Poggi Thibaut Vidal 《Journal of Global Optimization》2018,72(1):27-53
The partial digest problem consists in retrieving the positions of a set of points on the real line from their unlabeled pairwise distances. This problem is critical for DNA sequencing, as well as for phase retrieval in X-ray crystallography. When some of the distances are missing, this problem generalizes into a “minimum distance superset problem”, which aims to find a set of points of minimum cardinality such that the multiset of their pairwise distances is a superset of the input. We introduce a quadratic integer programming formulation for the minimum distance superset problem with a pseudo-polynomial number of variables, as well as a polynomial-size integer programming formulation. We investigate three types of solution approaches based on an available integer programming solver: (1) solving a linearization of the pseudo-polynomial-sized formulation, (2) solving the complete polynomial-sized formulation, or (3) performing a binary search over the number of points and solving a simpler feasibility or optimization problem at each step. As illustrated by our computational experiments, the polynomial formulation with binary search leads to the most promising results, allowing to optimally solve most instances with up to 25 distance values and 8 solution points. 相似文献
104.
Autrusson TB Sabra KG Leamy MJ 《The Journal of the Acoustical Society of America》2012,131(3):1928-1937
Previous ultrasonic studies have demonstrated that measurements of material nonlinearities can provide a means for detecting early signs of fatigue damage using both compressional (P) and Rayleigh (R) surface waves. However, these experimental studies have typically been limited to the direct wave arrival between the source and receiver in simple geometries where no reflection occurs. In particular, the degree of material nonlinearity is often quantified by the ratio of the cumulative amplitude of the first harmonic to that of the fundamental for the direct arrival only. Hence a practical question arises over the interpretation of ultrasonic measurements of material nonlinearities in the presence of reflected nonlinear waves. Thus, this article investigates the reflection problem of P or R waves at the edge of a homogeneous plate with quadratic nonlinearity using both a theoretical formulation, based on perturbation analysis, and direct numerical simulations using a Cellular Automata formulation. The numerical approach is first validated against an existing theoretical formulation for reflecting nonlinear P waves. It is then used to simulate the nonlinear reflection of R waves at a plate's edge for which no closed-form formulation is presently available. 相似文献
105.
We experimentally demonstrate the operation of a passively mode-locked Raman fiber ring laser with an ultrahigh repetition rate of 100 GHz and up to 430 mW of average output power. This laser constitutes a simple wavelength versatile pulsed optical source. Stable mode locking is based on dissipative four-wave mixing with a single fiber Bragg grating acting as the mode-locking element. 相似文献
106.
107.
Thibaut Mastrolia 《Stochastic Processes and their Applications》2018,128(3):897-938
In this paper, we provide conditions which ensure that stochastic Lipschitz BSDEs admit Malliavin differentiable solutions. We investigate the problem of existence of densities for the first components of solutions to general path-dependent stochastic Lipschitz BSDEs and obtain results for the second components in particular cases. We apply these results to both the study of a gene expression model in biology and to the classical pricing problems in mathematical finance. 相似文献
108.
109.
Thibaut Stoll Dr. Marcello Gennari Dr. Isabel Serrano Dr. Jérôme Fortage Dr. Jérôme Chauvin Dr. Fabrice Odobel Dr. Mateusz Rebarz Dr. Olivier Poizat Dr. Michel Sliwa Dr. Alain Deronzier Dr. Marie‐Noëlle Collomb 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):782-792
We report a very efficient homogeneous system for the visible‐light‐driven hydrogen production in pure aqueous solution at room temperature. This comprises [RhIII(dmbpy)2Cl2]Cl ( 1 ) as catalyst, [Ru(bpy)3]Cl2 ( PS1 ) as photosensitizer, and ascorbate as sacrificial electron donor. Comparative studies in aqueous solutions also performed with other known rhodium catalysts, or with an iridium photosensitizer, show that 1) the PS1 / 1 /ascorbate/ascorbic acid system is by far the most active rhodium‐based homogeneous photocatalytic system for hydrogen production in a purely aqueous medium when compared to the previously reported rhodium catalysts, Na3[RhI(dpm)3Cl] and [RhIII(bpy)Cp*(H2O)]SO4 and 2) the system is less efficient when [IrIII(ppy)2(bpy)]Cl ( PS2 ) is used as photosensitizer. Because catalyst 1 is the most efficient rhodium‐based H2‐evolving catalyst in water, the performance limits of this complex were further investigated by varying the PS1 / 1 ratio at pH 4.0. Under optimal conditions, the system gives up to 1010 turnovers versus the catalyst with an initial turnover frequency as high as 857 TON h?1. Nanosecond transient absorption spectroscopy measurements show that the initial step of the photocatalytic H2‐evolution mechanism is a reductive quenching of the PS1 excited state by ascorbate, leading to the reduced form of PS1 , which is then able to reduce [RhIII(dmbpy)2Cl2]+ to [RhI(dmbpy)2]+. This reduced species can react with protons to yield the hydride [RhIII(H)(dmbpy)2(H2O)]2+, which is the key intermediate for the H2 production. 相似文献
110.
Devièse T Ribechini E Baraldi P Farago-Szekeres B Duday H Regert M Colombini MP 《Analytical and bioanalytical chemistry》2011,401(6):1739-1748
Violet-purple residues collected from a Gallo-Roman burial dated back to the second half of the third century A.D. and excavated at Naintré (France) were chemically investigated by multi-analytical methodology involving the use of Raman spectroscopy, direct exposure-mass spectrometry (DE-MS) and high-performance liquid chromatography (HPLC-UV-visible). Little is known about funeral treatment and rituals during Roman times. Retrieving valuable information on these by chemical analysis of organic residues was thus a key aspect of this work. Analyses demonstrated the presence of the very precious purple colorant obtained from shellfish glands commonly known as Tyrian or royal purple and its exceptional preservation. Chemical investigation and archaeological evidence have shown that purple was widely spread after the deposition of the body for burial. These results are the earliest chemical evidence of purple colorant used during funeral rituals (not as textile dye) and enabled us to highlight new aspects of funeral practices in Roman times. 相似文献