积单元神经网络预测噪声环境的混沌时间序列

用人工神经网络预测噪声环境的混沌时间序列是一个重要的问题,因为许多实际的时间序列数据都是含噪声的。提出一种利用积单元神经网络(PUNN)预测噪声环境的混沌时间序列的方法,它采用了粒子群优化器(PSO)训练PUNN网络。用所提方法对Lorenz混沌序列做了仿真实验,结果表明:所提方法结构简单、泛化能力强,是一种有效的方法;当PUNN网络的输入节点数目为2或3时,预测精度更高,而且泛化能力也更强。

具有FIR突触的积单元神经网络预测时间序列

提出一种具有有限脉冲响应 (FIR)突触的积单元神经网络 (PUNN)结构 ,并用于预测混沌时间序列 这种神经网络结构既继承了标准PUNN的结构简单、信息存储能力强的优点 ,又更适合预测混沌时间序列 ,特别是在小的学习样本情况 分别用具有FIR突触的PUNN、标准PUNN以及模糊神经网络 (FNN)等 3种神经网络对小的样本混沌时间序列做了 1步和多步预测对比实验 结果显示具有FIR突触的PUNN比其他 2种神经网络预测精度都高

基于粒子群优化的积单元网络预测混沌序列

提出一种基于粒子群优化 (PSO)的积单元神经网络 (PU NN )预测混沌时间序列的方法 .PUNN信息存储能力强 ,但是它的训练却很困难 .PSO是一类基于群智能的随机全局优化技术 ,故该文用 PSO算法训练 PUNN.对 Mackey-Glass混沌序列分别用 PU NN和模糊神经网络方法做的单步及多步预测对比实验结果说明不仅用 PSO算法训练PUNN是有效的 ,而且用 PU NN预测混沌时间序列是一种有效的方法 .

东营凹陷东营三角洲沙三段中亚段古地貌特征及其对沉积的控制

东营凹陷沙三段中亚段发育9期特征明显的三角洲进积单元,古地貌对三角洲进积单元的控制作用明显。利用东营凹陷丰富的钻井和高精度三维地震数据,采用适用于该区的定量高精度古地貌恢复方法——滨线轨迹法,来重建研究区9期三角洲进积单元的古地貌特征,并揭示古地貌对沉积的控制作用。研究结果表明,东营三角洲在沙三段中亚段沉积时期古地貌整体呈现南缓北陡、斜坡向西迁移的特征。沉积体的分布范围和沉积样式与古地貌特征具有良好的耦合关系:三角洲沉积主要沿着东部和东南部凸起逐渐向湖盆推进,受物源供给能力和古地貌特征的影响,三角洲朵体沿斜坡向西延伸;深洼区主要发育半深湖—深湖相沉积,在坡度较大的斜坡前端沉积物易发生失稳而形成浊积砂体。

一口清乘法的单元积用倍数法最简便

所谓“一口清”指能一口读出多位数乘法的单元积，以便进行快速加(减)．这里的定俗成沿用这个通俗的词语．乘法由九九的递位叠加(或用倍数乘)得积到双九九的接加，中间要先熟习“本个”加“后进”．所谓道位叠加是慢镜头的表述，既要顾“本个”又要顾“后进”．更有后面几位数所造成的连续进位，因此，得单元积是较繁复的。

大型特斯拉变压器内铁芯成型叠积方式的研究

从大型特斯拉变压器对铁芯性能的基本要求出发 ,根据硅钢薄带、树脂粘接剂及叠片的物理机械性能 ,导出了内铁芯断面硅钢薄带成型曲线的数学公式 ,详细分析了内铁芯的结构形式、成型基本叠积单元及薄带插叠原则 ,最后 。

山东安丘地区郯庐断裂带古近纪冲积物震积岩序列

在郯庐断裂带的安丘—夏庄箕状盆地的古近纪朱壁店组厚层冲积层中,发育许多震积岩层。它们是由地震液化、地震裂隙充填、振动塌落、地震断裂和地震沉陷作用而形成的震积岩组合。通过野外观测、室内鉴定和比较地震地质学研究,鉴别出了液化砂岩脉、液化砂岩墙、液化砂岩团块、裂隙充填砂砾岩墙、震塌岩、地震成因层内断裂及地震沉陷构造等震积岩构造。根据震积岩构造的特征和有关的研究成果,本文建立了由A、B和C3个震积岩单元组成的震积岩序列。水饱和砂受强烈振动液化作用形成A单元;随后,由砂砾层或砂层的地震裂隙充填和震动塌落而形成B单元;最后,由层内断裂作用及地面沉陷作用生成C单元;该序列的3个单元反映了厚层冲积物的地震作用全过程。

ANALYSIS OF NONLINEAR PIEZOELECTRIC CIRCULAR SHALLOW SPHERICAL SHELLS BY DIFFERENTIAL QUADRATURE ELEMENT METHOD

The static behavior of piezoelectric circular spherical shallow shells under both electrical and mechanical loads is studied by using the differential quadrature element method (DQEM). Geometrical nonlinearity effect is considered. Detailed formulations and procedures are given for the first time. Several examples are analyzed and accurate results are obtained by the DQEM. Based on the results in this paper, one may conclude that the DQEM is a useful tool for obtaining solutions of structural elements. It can be seen that the shell shape may be theore tically controlled and snap through may occur when the applied voltage reaches a critical value even without mechanical load for certain geometric configurations.

ON THE PRODUCT OF RIESZ ALGEBRAS AND REPRESENTATION

Let { E i∶i∈I } be a family of Archimedean Riesz algebras.The product of Riesz algebras is denoted by Π i∈I E i .The main result in this paper is the following conclusion:there exists a completely regular Hausdorff space X such that Π i∈I E i is Riesz algebra isomorphic to C(X) if and only if for every i∈I there exists a completely regular Hausdorff space X i such that E i is Riesz algebra isomorphic to C(X i) .

Surface edge element method for 3-D electromagnetic computation

A surface edge element method is proposed and implemented in the study ofelectromagnetic scattering fields of general targets. The basis functions for surfaces of arbitraryshape are derived according to the geometrical properties of each triangular patch. The proposedbasis functions are 3-D linear functions and the tangential components of the vectors are continuousas the traditional edge element method. Combined field integral equations (CFIE) that include bothelectrical field and magnetic field integral equations are used to model the electromagneticscattering of general dielectric targets. Special treatment for singularity is presented to enhancethe quality of numerical solutions. The proposed method is used to compute the scattering fieldsfrom various targets. Numerical results obtained by the proposed method are validated by resultsfrom other numerical methods.

Sedimentary evolution since the late Last Deglaciation in the western North Yellow Sea

To decipher the sedimentary evolution and environmental changes since the late Last Deglaciation, two gravity cores were analyzed from the western North Yellow Sea (NYS). The two cores (B-L44 and B-U35) were sampled for grain size, clay minerals, detrital minerals, and 14C dating. They are comparable in lithofaies, and the observed succession was divided into four depositional units based on lithology and mineral assemblages, which recorded the postglacial transgression. Depositional unit 4 (DU 4) (before 11.5 ka) was characterized with enrichment in sand, and was interpreted as nearshore deposits in shallow water during the Younger Dryas Event. DU 3 (11.5-9.6 ka) displayed a fining-upward succession composed of sediments from local rivers, such as the Huanghe (Yellow) River, and from coastal erosion, which clearly were related to the Early Holocene transgression. Stable muddy deposition (DU 2) in NYS began to form at about 9.6 ka, which received direct supply of fine materials from the Shandong subaqueous clinoform. It is believed that the Yellow Sea circulation system played a major role in controlling the formation of fine sediment deposition in DU 1 (after 6.4 ka) after the sea level maximum.

Selection of organic Rankine cycle working fluid based on unit-heat-exchange-area net power

To improve energy conversion efficiency, optimization of the working fluids in organic Rankine cycles(ORCs) was explored in the range of low-temperature heat sources. The concept of unit-heat-exchange-area(UHEA) net power, embodying the cost/performance ratio of an ORC system, was proposed as a new indicator to judge the suitability of ORC working fluids on a given condition. The heat exchange area was computed by an improved evaporator model without fixing the minimum temperature difference between working fluid and hot fluid, and the flow pattern transition during heat exchange was also taken into account. The maximum UHEA net powers obtained show that dry organic fluids are more suitable for ORCs than wet organic fluids to recover low-temperature heat. The organic fluid 1-butene is recommended if the inlet temperature of hot fluid is 353.15-363.15 K or443.15-453.15 K, heptane is more suitable at 373.15-423.15 K, and R245 ca is a good option at 483.15-503.15 K.

Quadrature Element Vibration Analysis of Arbitrarily Shaped Membranes

The aim of the present study is to develop an efficient weak form quadrature element for free vibration analysis of arbitrarily shaped membranes.The arbitrarily shaped membrane is firstly mapped into a regular domain using blending functions,and the displacement in the element is assumed as the trigonometric functions.Explicit formulations are worked out for nodes of any type and a varying number of nodes.For verifications,results are compared with exact solutions and data obtained by other numerical methods.It is demonstrated that highly accurate frequencies can be obtained with a small number of nodes by present method.

某软土地区深基坑支护工程设计实例

本文以某软土地区深基坑支护工程为背景,结合工程实例,针对周围环境复杂多变,分析了放坡+土体加固方案、支护桩+内支撑支护体系、SMW工法桩的支护结构优点和缺点,节省了工程造价和工期。实施结果表明,对于某软土地区的断陷盆地南部冲湖积平原地貌单元,这三种基坑支护方案在基坑稳定性和止水方面均可取得不错的效果,将基坑施工对周边环境的影响控制在安全范围内,保护了工程环境,此经验可为今后类似工程设计提供一定的借鉴作用,值得推广。

Discrete element method for adhesion properties evaluation of deep-sea sediment from macro and micro perspectives

The adhesion between the mining machine and the deep-sea sediments will significantly affect the driving performance of the mining machine in the deep-sea environment.When the mining machine and the deep-sea sediment interaction simulation was carried out,the accuracy of the particle interaction parameters will directly affect the simulation results.This study proposed a method to systematically calibrate the interaction parameters between deep-sea sediment and grouser through the combination of experiment and simulation.The uniaxial compression test and macro adhesion test and corresponding discrete element numerical simulation were carried out,modifying the contact parameters until the simulation results are close to the experimental results.Then the micro-parameters of the JKR adhesion contact model were back calibrated with the test results,and the contact parameters between soil particle-soil particle and soil particle-metal are calibrated.Besides,the adhesion test shows that the adhesion forces were ranked in the order of 5052<STi80<TA2<TC4 under the same surface roughness,which indicates the aluminum alloy 5052 has the best anti-adhesion performance.The relationship between surface adhesion force and microscopic contact parameters was studied by discrete element numerical simulation,and the result shows that the coefficient of static friction and the coefficient of rolling friction has little effect on adhesion force.While it is mainly affected by the coefficient of restitution and surface energy,the surface adhesion force tends to decrease with the increase of the coefficient of restitution and increase with the growth of surface energy.The obtained parameters of soil particle to soil particle and soil particle to metal affecting the adhesion can contribute to the design optimization for the grouser of mining machines to decrease surface adhesion and enhance its movability and mining efficiency.

Origin of Sulfur and Mode of Gypsum Formation in Central Iraqi Soils

The δ18O and 8D values of gypsum crystallization water together with δ18O and 834S of sulfates were used as reliable techniques to study source of sulfur and mode of gypsum formation in selected central Iraqi soils. Six representative pedons on different geologic units were studied. The slope of 3.9 for δ18O and 8D plot of gypsum crystallization water showed that evaporation was the major process of gypsum deposition in the study area. The mean 834S value of ＋17.58 %0 showed that Cretaceous sea sulfate followed by Tertiary is the source of sulfur in studied soils. The heavier 834S value （＋17.58 %0） of the study area compared to central Iran （＋13.5 %） proved that gypsum in central Iraq soils has been formed in the later stage of evaporation and that Iraqi landforms were cut off from the Tethys seaway after central Iran was evolved.

Shadow Volume in Real-Time Rendering

This paper presents an optimization of shadow volume algorithm, which allow a rendering in real-time. This technique is based on previous works which makes it possible to obtain shadows in real-time, although the calculation of the silhouette requires a pretreatment of the geometry implemented on the CPU （Central Processing Unit）. By using last version of the GPU （Graphic Processing Unit）, the authors propose to implement the calculation of the silhouette on the GPU by using Geometry Shader. The authors present the step which made it possible to lead to a concrete implementation of this algorithm, the modifications which were made, as well as a comparative study of results, followed by a discussion of these results and choices of implementation.

Turnout fault prediction method based on gated recurrent units model

Turnout is one of the important signal infrastructure equipment,which will directly affect the safety and efficiency of driving.Base on analysis of the power curve of the turnout,we extract and select the time domain and Haar wavelet transform characteristics of the curve firstly.Then the correlation between the degradation state and the fault state is established by using the clustering algorithm and the Pearson correlation coefficient.Finally,the convolutional neural network(CNN)and the gated recurrent unit(GRU)are used to establish the state prediction model of the turnout to realize the failure prediction.The CNN can directly extract features from the original data of the turnout and reduce the dimension,which simplifies the prediction process.Due to its unique gate structure and time series processing features,GRU has certain advantages over the traditional forecasting methods in terms of prediction accuracy and time.The experimental results show that the accuracy of prediction can reach 94.2%when the feature matrix adopts 40-dimensional input and iterates 50 times.

Physical Modelling of the Drained Flow on a Suction Box of a Papermachine

Suction boxes are used in the paper industry to simultaneously drain a pulp suspension and form a fibre mat （or filter cake）. This research addresses the modelling of fibre deposition in the forming unit of an industrial papermachine, assuming a filtration process, and that of the flowing suspension drained through the building fibre mat and the wire on a suction box. From experimental data of the cumulative drained V volume, per unit surface area, for two vacuum pressures △P and 6 dwell times t, an extension of the classical law （t/V） versus V is proposed, validated and applied. This relation enables determining the average specific filtration resistance of the fibre mat over the box and the mass of solids deposited before and over the suction box. The model obtained is as precise as 1% and can be used to limit and reduce the energy consumption of drainage vacuum assisted devices such as suction boxes in the forming unit of industrial papermachines.