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11.
The conditional expectation of integrands and random sets is the main tool of stochastic optimization. This work wishes to make up for the lack of real synthesis about this subject. We improve the existing hypothesis and simplify the corresponding proofs. In the convex case we especially study the problem of the exchange of conditional expectation and subdifferential operators.  相似文献   
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Fluorescence line narrowing (FLN) spectroscopy was used to study the role of the polypeptide chain in influencing the spectrum of Zn-substituted cytochrome c (Zn cyt c) and metal-free cyt c (porphyrin cyt c). For both derivatives the spectra show characteristics of relaxed fluorescence from an inhomogeneously broadened sample. Zero phonon lines and phonon wings can be clearly distinguished, and vibrational frequencies of the ground and excited states were identified. The inhomogeneous distribution width for porphyrin cyt c is slightly wider than that of Zn cyt c and a second population of molecules was apparent in the porphyrin cyt c. The phonon coupling was greater for Zn cyt c than for porphyrin cyt c, which may be due to the extra coupling to the polypeptide chain by metal ligation.This work has been done in partial fulfillment of the requirements for the Doctor of Philosophy degree.  相似文献   
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二维随机激光器的模式选择及阈值与饱和特性   总被引:4,自引:0,他引:4       下载免费PDF全文
刘劲松  刘海  王春  吕健滔  樊婷  王晓东 《物理学报》2006,55(8):4123-4131
基于将Maxwell方程与四能级原子系统速率方程相结合而建立起随机激光时域理论,并利用有限时域差分法,研究了二维随机介质中激光模式的输出特性与介质尺寸、外形及抽运速率等参数的关系.结果表明,与传统激光模式相似,随机激光模式的强度随抽运速率的变化不仅具有阈值特性,而且具有饱和特性.基于模式特性对介质及抽运参数的依赖关系,提出了二维随机激光器的选模方式,在很大程度上不同于传统激光器的选模方式. 关键词: 随机激光器 模式选择 无序介质中的光学特性  相似文献   
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The feature selection consists of obtaining a subset of these features to optimally realize the task without the irrelevant ones. Since it can provide faster and cost-effective learning machines and also improve the prediction performance of the predictors, it is a crucial step in machine learning. The feature selection methods using support machines have obtained satisfactory results, but the noises and outliers often reduce the performance. In this paper, we propose a feature selection approach using fuzzy support vector machines and compare it with the previous work, the results of experiments on the UCI data sets show that feature selection using fuzzy SVM obtains better results than using SVM.  相似文献   
16.
《Electroanalysis》2006,18(24):2451-2457
This paper describes a layer‐by‐layer (LBL) self‐assembly process of chitosan (CTS) and gold nanoparticles (Au) on the pretreated negatively charged glassy carbon (GC) electrode to fabricate electrochemistry immunosensor with a nontoxic biomimetic interface, which provided an environment similar to a native system and allowed more freedom in orientation for immobilization of carcinoembryonic antibody (anti‐CEA) to monitor carcinoembryonic antigen (CEA). UV‐vis spectroscope, atomic force microscopy (AFM), and cyclic voltammetric (CV) measurements were used to follow the multilayer film formation. The performance of the biominetic interface and factors influencing the assay system were investigated in detail. The differential pulse voltammetry (DPV) current response is used for the CEA concentration assay. The dynamic range was from 0.50 to 80.00 ng mL?1 with a detection limit of 0.27 ng mL?1 at 3σ. In addition, the experiment results indicate that immobilization described in this proposed method exhibits a good sensitivity, selectivity, and stability.  相似文献   
17.
An automatic monitoring and intervention algorithm that permits the supervision of very general aspects in an univariate linear Gaussian state–space model is proposed. The algorithm makes use of a model comparison and selection approach within a Bayesian framework. In addition, this algorithm incorporates the possibility of eliminating earlier interventions when subsequent evidence against them comes to light. Finally, the procedure is illustrated with two empirical examples taken from the literature. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
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短脉冲激光加热模型的遴选原则   总被引:2,自引:0,他引:2       下载免费PDF全文
胡汉平  董艺 《强激光与粒子束》2006,18(10):1593-1596
 利用推导出的1维半空间光致热弹性应力响应的精确解,对激光与材料相互作用的加热模型的选取进行了研究。理论分析和计算结果表明:常用的表面加热模型只有在热穿透深度远大于光吸收长度时有效,若将其应用于超短脉冲激光(ps以下量级)加热的情况,可能会导致较大的误差;皮秒和飞秒激光辐照的热效应须用体加热模型计算。  相似文献   
20.
We present a Bayesian theory of object identification. Here, identifying an object means selecting a particular observation from a group of observations (variants), this observation (the regular variant) being characterized by a distributional model. In this sense, object identification means assigning a given model to one of several observations. Often, it is the statistical model of the regular variant, only, that is known. We study an estimator which relies essentially on this model and not on the characteristics of the “irregular” variants. In particular, we investigate under what conditions this variant selector is optimal. It turns out that there is a close relationship with exchangeability and Markovian reversibility. We finally apply our theory to the case of irregular variants generated from the regular variant by a Gaussian linear model.  相似文献   
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