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The vast size of real world stochastic programming instances requires sampling to make them practically solvable. In this
paper we extend the understanding of how sampling affects the solution quality of multistage stochastic programming problems.
We present a new heuristic for determining good feasible solutions for a multistage decision problem. For power and log-utility
functions we address the question of how tree structures, number of stages, number of outcomes and number of assets affect
the solution quality. We also present a new method for evaluating the quality of first stage decisions. 相似文献
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Francisco J. Salgado Sara Vázquez Amparo Pérez-Díaz Pilar Arias 《Analytica chimica acta》2010,658(1):18-3648
Serum is a typical sample for non-invasive studies in clinical research. Its proteome characterization is challenging, since requires extensive protein depletion. Methods used nowadays for removal of high-abundance proteins are expensive or show quite often a low loading capacity, which has strong repercussions on the number of samples and replicates per analysis.In order to deplete immunoglobulins (Igs) and albumin (HSA) from 1 mL serum samples, we have developed a protocol based on a combination of thiophilic chromatography, not previously used in clinical proteomics, and a HSA-specific resin. Ig/HSA-depleted samples, immunoglobulinome and albuminone were analyzed by 2-DE. Thiophilic chromatography, coupled with HSA-depletion, allows a good 2-DE resolution as well as the visualization of new spots. Moreover, it yields enough protein to evaluate technical variability and facilitate subsequent protein identification. To validate the protocol, we carried out a preliminary comparative study between triplicate Igs/HSA-depleted serum samples from healthy control individuals and recently diagnosed/untreated rheumatoid arthritis (RA) patients. RA patients showed several acute phase proteins, as well as additional serum proteins, differentially and significantly regulated.Therefore, thiophilic chromatography can be used as an efficient and economical method in 2-DE to deplete immunoglobulins from large human serum samples before a more extensive fractioning. 相似文献
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为减小物资生产与配送不协调造成的成本及生产资源浪费,建立了考虑推动式生产调度的物资配送优化模型,并针对标准模拟退火算法受随机因素影响易陷入局部最优的缺点,设计带有回火与缓冷操作的改进模拟退火算法对模型求解,确定了优化的车辆配送路线以及物资生产计划。对比实验结果表明:相对于单纯的物资配送优化模型,考虑推动式生产调度的配送优化模型,能够有效减小物资滞留时间以及配送延误成本;相较于标准模拟退火算法,改进算法搜索到了更优解,且计算结果的标准差减小了93.42%,稳定性更好;同时,改进模拟退火算法具有较低的偏差率,在中小规模算例中求解质量较高,平均偏差率在0.5%以内。 相似文献
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Stanislava G. Dmitrienko Elena V. KochukAuthor VitaeVladimir V. ApyariAuthor Vitae Veronika V. TolmachevaAuthor VitaeYury A. ZolotovAuthor Vitae 《Analytica chimica acta》2014
Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid–liquid and solid-phase extraction, dispersive liquid–liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed. 相似文献
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对于高介电常量分形粗糙面的双站散射与透射的数值计算,须用密网格来剖分粗糙面,这样就产生了计算内存大和计算时间长的问题.双网格法通常可以用来减少计算机计算所需内存和计算时间.为计算任意角度(包括低掠角)TE和TM波入射下的高介电常量分形粗糙面在各种物理条件下的双站散射与透射,将双网格法和前后向迭代与谱积分加速法相结合,发展了新的数值计算方法,并验证了散射与透射的能量守恒,讨论了双站散射与透射角度性变化的特征.
关键词:
双站散射
透射
PBTGFBMSAA
分形粗糙面 相似文献
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《Operations Research Letters》2021,49(2):164-170
Stochastic semidefinite programming (SSDP) is a new class of optimization problems with a wide variety of applications. In this article, asymptotic analysis results of sample average approximation estimator for SSDP are established. Asymptotic analysis result already existing for stochastic nonlinear programming is extended to SSDP, that is, the conditions ensuring the convergence in distribution of sample average approximation estimator for SSDP to a multivariate normal are obtained and the corresponding covariance matrix is described in a closed form. 相似文献
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