Computation of extreme eigenvalues in higher dimensions using block tensor train format

We consider approximate computation of several minimal eigenpairs of large Hermitian matrices which come from high-dimensional problems. We use the tensor train (TT) format for vectors and matrices to overcome the curse of dimensionality and make storage and computational cost feasible. We approximate several low-lying eigenvectors simultaneously in the block version of the TT format. The computation is done by the alternating minimization of the block Rayleigh quotient sequentially for all TT cores. The proposed method combines the advances of the density matrix renormalization group (DMRG) and the variational numerical renormalization group (vNRG) methods. We compare the performance of the proposed method with several versions of the DMRG codes, and show that it may be preferable for systems with large dimension and/or mode size, or when a large number of eigenstates is sought.     

Addendum to “On the consistency of MPS” [Comput. Phys. Comm. 184 (3) (2013) 732–745]

The analogies between the Moving Particle Semi-implicit method (MPS) and Incompressible Smoothed Particle Hydrodynamics method (ISPH) are established in this note, as an extension of the MPS consistency analysis conducted in Souto-Iglesias et al. (2013).     

Analysis of the Void Distribution in a Circular Tube with the Two-Fluid Particle Interacthion Method

A particle interaction method called MPS (Moving Particle Semi-Implicit) has been developed in recent years, which formulates the differential operators in Navier-Stokes' equation as interactions between particles characterized by a kernel function and adopts a mesh-free algorithm. This method is suitable especially for treating fluid breakup. We have extended this method to a two-fluid (liquid-liquid and gas-liquid) system and introduced a potential-type surface tension to calculate the two-phase flow without experimental correlation. With this extended method, a several number of two-phase flow experiments were analyzed successfully as reported in our previous paper. Herein, as one of the verification studies, the experiment by Valukina et al. was analyzed to show that our method could reproduce the bubble size effect on the radial void distribution in a circular tube. The experiment showed that the radial void distribution changes drastically as the bubble size changes. Our previous work with SIMMER-IV code which has a general solver for multi-phase flows revealed that the “lateral lift force” and “wall force” should be introduced into the momentum conservation equation to reproduce the bubble size effect. We evaluated these forces using the velocities of particles calculated by our particle method and compared with the SIMMER-IV results.     

MPS课程模块化教学的思考

开展专业课的模块化教学,是对传统教学模式的改革。以MPS课程为例,对模块化教学的教学内容、教学方法和教学评价等问题进行总结和思考,以便更好地提高机电一体化专业学生的综合能力,更好地服务就业。     

降低烧结生产成本的几点作法

指出了冶金企业在市场竞争中要降低成本，烧吉应首先优化原、燃料结构、提高科技含量，节能降耗，生产高品位，高碱度的烧结矿。     

济(源)钢小球团烧结生产实践

介绍了济钢烧结在技改过程中，采用小球团烧结技术及多项专利的情况。技改后，混合料的成球率大大提高，料层由300mm提高到550到600mm，固体燃料单耗大幅度降低。     

MRP Ⅱ系统中主生产计划的关键技术及过程模型研究

主生产计划系统是ＭＲＰⅡ系统的重要组成部分,本文针对ＭＰＳ的特点,详细地分析和描述了ＭＰＳ的功能及处理流程,并对ＭＰＳ的一些关键技术进行了研究。提出了基于Ｐｅｔｒｉ网的ＭＰＳ过程模型和ＭＰＳ基本算法。     

基于MPS方法的自密实混凝土流动数值模拟

采用三维移动粒子半隐式(MPS)法来分析和预测自密实混凝土(SCC)的流动性,对L形箱试验进行数值模拟,对比分析了数值模拟与试验中SCC的流动形态和流动时间.在此基础上,研究了L形箱试验和V形漏斗试验中塑性黏度对SCC流动性的影响,并建立了SCC密度和塑性黏度与V形漏斗试验下落时间的关系.结果表明:使用基于Bingham流变模型的MPS方法可以较好地模拟SCC的流动特性,且精度较高;MPS方法可以对SCC在施工过程中的流动时间和流动形态进行模拟预测,结合流变参数分析可以为SCC工程的设计和施工实践提供参考依据.     

基于相序的多点地质统计学相建模方法及其应用

目前的多点地质统计建模方法均以一定维度的数据模板为载体,将概率或几何距离作为建模工区未知区域模拟取值的判定标准,该判定标准在地质建模时与地质含义的联系较为薄弱。针对上述不足,文章回归地质建模的本质,考虑相建模过程中数据事件与训练图型对比的地质含义,提出基于相序的多点地质统计相建模方法。该方法以具有沉积学意义的相序为基本的相似度对比单元,新建适合于相序相似度对比的动态数据模板,采用句法模式识别技术,通过动态规划方法计算数据事件中已知相序与训练图型中对应相序的相似度,对建模工区未知区域进行相模拟,实现了从沉积学意义出发对强非均质性储层进行多点地质统计学建模。理想模型和塔河X区三角洲前缘储层沉积相模拟表明,本文方法能够有效重现训练图像所显示的各地质体的几何形态,较好地反映储层不同相的沉积展布规律,大幅提高了相建模的精度。该方法将沉积学与多点地质统计学有效结合,提出了一种全新的多点地质统计学相似度对比方法和多点地质统计学建模框架,为复杂储层的相建模提供了一种新的方法。     

GE RX3i系统设计与虚拟对象应用 第6讲 GERX3i在模块化加工站的设计

模块化加工系统是将定制产品的制造问题通过产品重组和过程重组转化为或部分转化为批量制造问题,即提供给用户的是全新的、定制的个性化产品,而实际产品则主要由标准的模块组成。本文介绍了GE RX3i在模块化加工站中的设计。