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排序方式: 共有1071条查询结果,搜索用时 31 毫秒
971.
Multiple objective combinatorial optimization problems are difficult to solve and often, exact algorithms are unable to produce
optimal solutions. The development of multiple objective heuristics was inspired by the need to quickly produce acceptable
solutions. In this paper, we present a new multiple objective Pareto memetic algorithm called PMSMO. The PMSMO algorithm incorporates an enhanced fine-grained fitness assignment, a double level archiving process and a local search procedure
to improve performance. The performance of PMSMO is benchmarked against state-of-the-art algorithms using 0–1 multi-dimensional multiple objective knapsack problem from the
literature and an industrial scheduling problem from the aluminum industry. 相似文献
972.
973.
974.
Lecrenier Foerster Wolf Sand O. Scheen Karl Hallmann A. Fischer John G. Fairchild G. L. Heath Frary Irving H. Buckminster Edgar F. Smith T. Slater Price und A. W. T. Hyde 《Fresenius' Journal of Analytical Chemistry》1912,51(12):761-765
Ohne Zusammenfassung 相似文献
975.
On the basis of rigorous analysis supported by numerical computation, a systematic study is presented to locate and examine chaotic Kolmogorov flows resulting from the interaction of a basic steady-state flow and oscillatory modes. Referenced to suitably chosen initial conditions of the Kolmogorov flow model, these oscillatory modes are derived from the equation linearized around the basic steady-state flow. The numerical experiments provide insight into the transition process from secondary self-oscillation flows or secondary steady-state flows to chaotic Kolmogorov flows. 相似文献
976.
De-Yi Wang Yun Liu C. Perdomo Artiles Dennis Price 《Polymer Degradation and Stability》2007,92(8):1592-1598
A reactive extrusion technology was adopted to synthesize a flame retardant (ER), based on the esterification of melamine phosphate and pentaerythritol. The ER imparts good flame retardancy and non-dripping for polyethylene (PE) when combined with ammonium polyphosphate to yield an intumescent polyethylene (PE-IFR). The performance of this intumescent system has been enhanced by the addition of small amounts (0.2%) chelated copper(II)salicylaldehyde (CuSA) and salicylaldoxime, (CuSAO). The thermal stabilization and burning behaviour of the flame retardant PE system have been investigated by TGA, LOI, the UL-94 test and cone calorimetry. All formulations studied provide good flame retardant behaviour, with LOI ≥ 27.4 and UL-94 V-0 rating. The onset of decomposition in TGA for flame retarded PE (PE-IFR, PE-IFR-CuSA and PE-IFR-CuSAO) commences at lower temperature than that of PE with release of blowing agent, but continues to a higher temperature, leaving a greater residue. Significant differences have been observed in burning behaviour using cone calorimetry, between flame retarded PE (PE-IFR, PE-IFR-CuSA and PE-IFR-CuSAO) and PE, showing decreases in HRR, PHRR, MLR, FIGRA and CO emission. 相似文献
977.
This note is a continuation of the earlier paper [Chen, Z. M., Price, W. G.: Time dependent periodic Navier–Stokes flows on
a two-dimensional torus. Commun. Math. Phys. {\bf 179}, 577–597 (1996)], where the evidences of the occurrence for the time
dependent periodic Navier–Stokes flows were found based on a combination of analysis and computation. This investigation is
now confirmed via rigorous analysis. The existence of the time dependent periodic Navier–Stokes flows on a two-dimensional
torus is proved.
Received: 4 August 1998 / Accepted: 9 April 1999 相似文献
978.
非线性流体-刚体结构相互作用问题的一种数值模拟方法 总被引:4,自引:0,他引:4
给出了一种模拟非线性流体-刚体结构相互作用问题的数值方法.文中假定结构承受大的刚体运动,流体流动受非线性有粘或无粘的场方程支配并满足自由表面和两相耦合界面上的非线性边界条件,利用任意拉氏-欧氏(ALE)网格系统构造了数值模型.采用所探讨的多块数值格式,允许可动重造网格间有独立的相对运动,从而克服了流体网格与固体大运动匹配的困难.通过数值离散化,导出了描述非线性流固耦合动力学的数值方程并应用耦合迭代过程对其作了求解.通过算例,说明了所提出数值模型的应用. 相似文献
979.
Tarbert CM Watts DP Aguar P Ahrens J Annand JR Arends HJ Beck R Bekrenev V Boillat B Braghieri A Branford D Briscoe WJ Brudvik J Cherepnya S Codling R Downie EJ Föhl K Glazier DI Grabmayr P Gregor R Heid E Hornidge D Jahn O Kashevarov VL Knezevic A Kondratiev R Korolija M Kotulla M Krambrich D Krusche B Lang M Lisin V Livingston K Lugert S Macgregor IJ Manley DM Martinez M McGeorge JC Mekterovic D Metag V Nefkens BM Nikolaev A Novotny R Owens RO Pedroni P Polonski A Prakhov SN Price JW Rosner G 《Physical review letters》2008,100(13):132301
We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The 12C(gamma,pi(0))(12)C*(4.4 MeV) reaction has been studied with the Glasgow photon tagger at MAMI employing a new technique which uses the large solid angle Crystal Ball detector both as a pi(0) spectrometer and to detect decay photons from the excited residual nucleus. The technique has potential applications to a broad range of future nuclear measurements with the Crystal Ball and similar detector systems elsewhere. Such data are sensitive to the propagation of the Delta in the nuclear medium and will give the first information on matter transition form factors from measurements with an electromagnetic probe. The incoherent cross sections are compared to two theoretical predictions including a Delta-hole model. 相似文献
980.
Nykter M Price ND Larjo A Aho T Kauffman SA Yli-Harja O Shmulevich I 《Physical review letters》2008,100(5):058702
Network structure strongly constrains the range of dynamic behaviors available to a complex system. These system dynamics can be classified based on their response to perturbations over time into two distinct regimes, ordered or chaotic, separated by a critical phase transition. Numerous studies have shown that the most complex dynamics arise near the critical regime. Here we use an information theoretic approach to study structure-dynamics relationships within a unified framework and show that these relationships are most diverse in the critical regime. 相似文献