木糖醇发酵过程软测量

针对木糖酵发酵过程中关键参数在线测量难的问题，建立了基于均匀设计和遗传算法的神经网络结构法，实现其在线软测量，实验表明，该模型可实现在线测量。     

木糖醇发酵过程软测量

针对木糖醇发酵过程中关键参数在线测量难的问题 ,建立了基于均匀设计和遗传算法的神经网络结构法 ,实现其在线软测量 ,实验表明 ,该模型可实现在线测量     

一种利用多神经网络结构建立非线性软测量模型的方法

采用多种神经网络结构建立软测量模型。建模所用的样本数据经过Ｋｍｅａｎｓ聚类方法分成多组训练数据,每组数据建立一个单个神经网络模型,再通过ＰＣＲ方法连接起来得到整个模型的输出,从而显著地提高了模型的精确度和鲁棒性。仿真研究表明,采用该建模方法能够达到较好的建模效果。     

粗糙分类器的多模型软测量建模方法

根据多模型可以改善模型估计精度,提高泛化性的思想,提出了1种粗糙分类器的多模型软测量建模方法。该方法采用聚类、分类相结合的方式对数据进行分组训练,在一定程度上消除了矛盾样本点可能对模型精度造成的影响。对各组样本利用支持向量回归机建立回归子模型,得到多模型软测量系统。同时,通过向粗糙集引入相似度作为评价样本间相似性的指标,解决了传统粗糙集无法识别训练样本集中未出现过的模式的问题。通过引入概率测度,利用概率公式作为粗糙集分类的决策规则,简化了算法。基于上述理论构造的粗糙分类器,有效地提高了分类器的分类精度,确保了各子模型的估计精度。将该方法应用于双酚A生产过程的质量指标软测量建模,仿真结果表明了该算法的有效性。     

软测量技术在DehaV DCS上的实现和应用

针对丁二烯生产装置精馏塔塔顶控制回路存在的问题，建立了软测量模型，并设计了串级推断控制回路。利用从集散控制系统采集的大量现场数据，运用基于多元线性回归方法的软测量建模技术，建立了塔顶中丁二烯产品纯度的软测量模型．实现了产品质量闭环控制。通过DeltaV DES系统实现控制回路的改造。实际使用证明，该软测量模型具有良好的特性，较高的估计精度和实时性；塔的控制更加平稳，节约了能耗，具有较好的经济效益。     

丙烯腈收率软测量

本文研究了基于PCA-RBFNN的丙烯腈收率软测量建模方法;并以此为基础,采用FCM聚类方法对样本数据分类,建立了基于多模型的丙烯腈收率软测量模型.实验结果表明,基于多PCA-RBFNN的丙烯腈收率软测量模型与有关方法比较,预估效果最好.     

贝叶斯分类器的关联向量机多模型软测量建模

为了改善软测量模型的估计精度,提出了一种基于贝叶斯分类算法和关联向量机的多模型软测量建模方法。采用贝叶斯分类器对样本数据集进行分类,并对不同类别的输入数据分别建立关联向量回归机子模型,用“切换开关”方式组合作为最终的软测量模型输出。将该方法应用于双酚A生产过程的质量指标软测量建模,仿真结果表明：与单模型支持向量机相比,该方法估计精度较高,具有一定的应用价值。     

基于Bootstrap多神经网络的软测量方法

针对原油蒸馏过程常规软测量模型难以适应原油进料性质变化的问题,提出Bootstrap多神经网络的非线性软测量处理策略。通过Bootstrap算法复制出训练集样本空间上的多个样本子空间,训练出多神经网络模型,避免了单个神经网络易于陷入局部最优及过度训练的弱点,具有较高的准确率和泛化能力。本处理策略用于建立常压塔一线干点的软测量模型,仿真结果表明模型预测准确率和鲁棒性较好,对原油性质变化具有较好的适应性。该方法将会改进实际蒸馏过程在进料性质变化情况下的产品质量指标的软测量精度。     

基于神经网络的污水处理软测量系统的研究

针对污水处理质量指标无法在线检测的问题,提出了基于人工神经网络的软测量方法。构造了污水处理质量软测量的神经网络结构,运用实际工业污水处理过程测量数据对BP神经网络进行了训练和仿真。结果表明,实能准确地进行污水处理质量的实时估计,实现污水处理质量的实时控制。     

基于改进RBF网络的乙烯纯度软测量建模方法

对兰州某石化厂乙烯精馏塔产品质量进行了软测量建模研究,针对经典RBF神经网络建模时存在的问题,提出了一种改进的RBF网络结构,增加了从输入直接到输出的线性环节,应用最近邻聚类和最陡下降法训练改进后的网络,实验结果表明改进后的网络具有较好的网络性能,适用于乙烯精馏塔产品质量的软测量建模和预测.     

Effective solution of certain problems of theory of schedulings of nets

Cybernetics and Systems Analysis -     

Complexity of families of learning algorithms and estimation of the nonrandomness of extraction of empirical regularities

The paper presents a general approach to the evaluation of the complexity of classes of algorithms, so-called pVCD-method. To develop this method, all the examined families of models of empiric generalization were restricted to classes implementable on computers and, wider, by examining their partially recursive representations. Within the framework of the algorithmic approach, the concept of Kolmogorov’ complexity of algorithms for the recognition of properties or the extraction of regularities is proposed. The method proposed to evaluate the nonrandomness of the extraction of empirical regularities is based on this concept.     

变电站一次设备喷涂PRTV用量的分析

对国网宁夏电力检修公司宁安运维站近2年来一次设备喷涂PRTV用量的统计数据进行分析整理,得出各类一次设备按照标准要求喷涂PRTV时的用量估算值,并针对现存作业中存在的问题,提出相应解决方案。     

Analysis of microdensitometric data in terms of probability of cleavage of DNA

Computer-aided analysis of autoradiographic films of DNA fragments is presented. The Powell least-squares procedure is used for optimization of parameters for components of complex densitometric curves. Since each densitometric spectrum may be divided for several non-overlapped blocks of bands, there is no upper limit on the number of parameters which must be optimized. Eight shapes for the component bands are utilized: symmetric and asymmetric Gauss and Cauchy functions, direct, symmetric and asymmetric product of Gauss function and inverse of Cauchy function, and log-normal function. The probability of DNA cleavage is calculated with correction for multiple cuts. The methods presented was applied to detailed analysis of densitometric spectra of a 21-bp DNA restriction fragment and allowed for direct correlation between structural microheterogeneity of DNA and the resulting cutting pattern. This method should facilitate the analysis of densitometric data from antibiotic-induced cleavage of DNA and footprinting experiments.     

联合收割机脱粒滚筒恒速智能控制器设计

研究了轴流式联合收割机的控制问题,给出了联合收割机脱粒滚筒的数学模型,介绍了基于模式识别的智能控制原理,建立了联合收割机脱粒滚筒恒速控制模型,设计了基于模式识别的智能恒速控制器.应用Matlab/Simulink进行了控制器仿真,其结果表明,将基于模式识别的智能控制应用于联合收割机脱粒滚筒的恒速控制,其过渡过程平稳、响应速度快、无超调、无振荡并且无稳态误差.     

An estimate of numbers of terms of semicycles of delay difference equations

In this paper, we study the semicycles of oscillatory solutions of the delay difference equation y_n+1 − y_n + p_ny_n-k = 0, where p_n is a sequence of nonnegative real numbers and k is a positive integer. Upper bound of numbers of terms of semicycles are determined in the case when

Our results improve and complement known results in literature.     

Complexity of approximation of 3-edge-coloring of graphs

The problem to find a 4-edge-coloring of a 3-regular graph is solvable in polynomial time but an analogous problem for 3-edge-coloring is NP-hard. To make the gap more precise, we study complexity of approximation algorithms for invariants measuring how far is a 3-regular graph from having a 3-edge-coloring. We show that it is an NP-hard problem to approximate such invariants with an error O(n1−ε), where n denotes the order of the graph and 0<ε<1 is a constant.     

Modifications of the method of variation of parameters

In spite of being a classical method for solving differential equations, the method of variation of parameters continues having a great interest in theoretical and practical applications, as in astrodynamics. In this paper we analyse this method providing some modifications and generalised theoretical results. Finally, we present an application to the determination of the ephemeris of an artificial satellite, showing the benefits of the method of variation of parameters for this kind of problems.