Orientational analysis—a supplement to dimensional analysis—I

A method for extending the methods of dimensional analysis is based upon assigning “orientational” symbols to physical quantities such as area, force and angle which are spatially oriented. These symbols are shown to form a noncyclic group with four members, and they can be used to derive additional information that resolve problems incompletely solved by conventional dimensional analysis.     

Orientational analysis, tensor analysis and the group properties of the SI supplementary units—II

A method for extending the methods of dimensional analysis is based upon assigning “orientational” symbols to physical quantities such as area, force and angle which are spatially oriented. These symbols are shown to form a noncyclic group with four members, and they can be used to derive additional information that resolve problems incompletely solved by conventional dimensional analysis.     

量纲分析的基础及其应用研究

量纲分析是研究物理问题重要方法之一．在研究有关量纲分析的基本理论问题的基础上，提出了关于量纲分析和应用的一些新见解、新方法，引入了量纲式的向量表示法，提出了量纲的幂级数定理和解系定理，有利于从量纲角度来研究复杂的物理问题。     

On Constitutive Equations and Dimensional Analysis

A method of obtaining a system of partial differential equations from the invariance of a constitutive function under some restrictions of a continuous group of transformations is shown. Using the theory of partial differential equations, a set of independent solutions and dependence relationship is derived. Group theory technique is employed relative to dimensional analysis to show how the transformation from one unit system to another results in a relationship among different dimensional variables. An alternative proof of Buckingham's Pi-theorem is presented.     

深基坑支护体系的空间变形性状分析

为探讨在工程上简便实用的从三维空间角度来整体分析深基坑支护体系变形状的有效方法,对基坑支护结构的连续介质三维有限元模型进行分析,得出了分阶段开挖情况下基坑混合支护体系空间变形的性状,并与按一次性开挖的分析结果进行了比较,从分析结果可知,支护结构上部的位移计算结果与理否考虑开挖掘的阶段性有关关系,而按空间问题还是平面问题来分析,角点附近的位移计算结果有较大判别。     

基于PCA的SOM网络在基因数据聚类分析中的应用

把主分量分析（PCA）方法和自组织特征映射网络（SOM）相结合,应用到基因数据聚类分析中。首先对基因数据集进行PCA分析,提取出少量的特征主分量,再对数据集进行降维。这些主分量基本上可以反映原数据集的综合信息,然后应用SOM网络对得到的特征分量进行聚类分析,把相似的基因划分到一个区域。实验结果表明,与单一地选用SOM网络进行聚类分析相比,该方法有较高的分类正确率及较为清晰的分类边界,是一种非常有效的聚类分析方法。     

Learning a subspace for clustering via pattern shrinking

Clustering is a basic technique in information processing. Traditional clustering methods, however, are not suitable for high dimensional data. Thus, learning a subspace for clustering has emerged as an important research direction. Nevertheless, the meaningful data are often lying on a low dimensional manifold while existing subspace learning approaches cannot fully capture the nonlinear structures of hidden manifold. In this paper, we propose a novel subspace learning method that not only characterizes the linear and nonlinear structures of data, but also reflects the requirements of following clustering. Compared with other related approaches, the proposed method can derive a subspace that is more suitable for high dimensional data clustering. Promising experimental results on different kinds of data sets demonstrate the effectiveness of the proposed approach.     

高校图书馆核心竞争力评价研究

高校图书馆在辅助教学与科研方面起着重要的支撑作用，这正是高校图书馆核心竞争力的体现。本文从核心竞争力的资源与能力观点出发，构建了高校图书馆核心竞争力的评价指标体系，提出了一种三维评价模型并进一步分析了其投影操作。本文还给出了适用于评价多个研究对象的最优点法。应用此方法，本文对国内10所著名大学的图书馆进行了实证研究，发现制约高校图书馆核心竞争力充分发挥的主要因素在于馆员素质方面。对此，本文提出了相应的措施与建议。     

Two dimensional quaternion valued singular spectrum analysis with application to image denoising

Compared to the traditional single color plane based image denoising methods, the quaternion valued singular value decomposition (QSVD) exploits the relationship among different color planes. Hence, it has been applied to the color image denoising. On the other hand, compared to the non-overlapping based image denoising methods, the two dimensional real valued singular spectrum analysis (2DSSA) constructs the trajectory matrix with many elements in the matrix being overlapped. Since the 2DSSA exploits the local information within each color plane, it has also been applied to the single color plane based image denoising. However, neither these two image denoising methods can exploit the relationship among the color planes and the local information within each color plane simultaneously. Therefore, this paper proposes a two dimensional quaternion valued singular spectrum analysis (2DQSSA) based method for performing the color image denoising. Our proposed method can enjoy the advantages of both methods. However, the most critical issue for the 2DQSSA is on the selection of these 2DQSSA components. This paper finds that the optimal total number of the 2DQSSA components used for performing the reconstruction is monotonic decreasing with respect to the power of the noise in the image. Therefore, the polynomial fitting approach is proposed to model this relationship. Since the 2DQSSA based denoising method exploits the relationship among the red color plane, the green color plane and the blue color plane, the 2DQSSA based denoising method outperforms the conventional single color plane based denoising methods. Moreover, since the 2DQSSA based denoising method also exploits the local relationship within each color plane, the 2DQSSA based denoising method outperforms the non-overlapping based methods.     

LOW DIMENSIONAL GALERKIN METHOD AND ITS ROLE IN QUALITATIVE ANALYSIS OF NONLINEAR BEHAVIOR OF BLUFF BODY WAKES

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基于主体间多维交互的产学研知识转移机理

本文以促进产学研合作中的知识转移效果为目标,从主体间多维交互的视角,选择“沈鼓-大工”产学研合作为案例样本,采用探索性单案例研究方法,基于SECI知识转移过程模型,探讨产研双方在知识转移过程中的交互形式及其作用机理。首先,从项目合作、技术中心、合作研究院等多种合作形式的演变过程介绍了“沈鼓-大工”合作历程;其次,基于案例信息的分析,发现在产研合作知识转移过程中存在利益交互、情感交互、任务交互、行为交互这四个维度的主体间交互,分析了四个维度的主体交互在知识转移过程中的体现形式;然后探究了这四个维度的主体交互在产学研合作中知识转移的作用机理,发掘了不同交互维度在知识转移不同阶段发挥的多元化作用;最后,提出了基于主体间多维交互的产学研知识转移过程整合模型,并阐释了多维交互的一般过程。     

Analysis and pinning control for generalized synchronization of delayed coupled neural networks with different dimensional nodes

This paper investigate the generalized synchronization and pinning adaptive generalized synchronization for delayed coupled different dimensional neural networks with hybrid coupling, respectively. First, some sufficient conditions for reaching the generalized synchronization and pinning generalized synchronization of the considered network are acquired by using some inequality techniques and Lyapunov functional method. Second, because the precise parameter values of network cannot be obtained in some situations, we also purse the study on the generalized synchronization analysis and pinning control for the case of coupled different dimensional neural networks with parameter uncertainties. Third, two numerical examples are provided for substantiating the effectiveness of the derived results.     

基于业务维生命周期的螺旋式开发方法研究

将业务维生命周期法和螺旋式开发方法引入数据仓库的开发设计过程,提出了基于业务维生命周期的螺旋式开发方法,该方案能以螺旋盘升的方式逐步拓展数据仓库系统,使数据仓库能动态地满足用户不断变化的决策需求。应用该方法进行了设备管理数据仓库系统的开发,证明了该方法的有效性。     

The origin of dimensional analysis

A paper by Macagno (3) in this Journal is discussed. The origin of the concept of physical dimensions is traced back to ideas previously used in analytic geometry. Descartes' use of the word “dimension” in the study of physical magnitudes is shown to have properties completely different from Fourier's dimensions, being therefore unimportant to the evolution of dimensional analysis. It is also shown that the principle of homogeneity was used in the derivation of physical equations sixty years prior to the publication of Fourier's work, and that the latter was aware of this paper, that may be considered the earliest publication on dimensional analysis.     

基于顾客价值的电子商务网站竞争优势的构建

在对已有的基于顾客价值构建企业竞争优势的方法进行评价的基础上,提出了顾客价值构建电子商务网站竞争优势的流程;以T、J、Z、D 4家电子商务网站的消费者为调查对象,通过问卷调查及验证性因子分析识别出电子商务网站顾客价值驱动因素;利用问卷调查、层次分析、方差分析等方法分析顾客价值要素,并建立重要性/竞争差异/顾客期望三维模型,对各象限要素进行具体的分析及解读,分析4家电子商务网站的竞争优、劣势,提出各电子商务网站竞争战略备选方案.     

管内气液两相流动空泡率传播模型研究

以波传播的观点 ,将流动工况视为连续波与动力波相互作用在特定流动条件下的非线性解 ,尝试提出了两相流分析的一种新思路 .从一维气液两相流守恒方程出发 ,应用气液两相流漂移流模型 ,推导了空泡率双曲型守恒方程 ,用特征线法数值求解气液两相流空泡率分布的传播过程 ,对传播稳定性和流型转变进行讨论 .数值分析表明 ,低空泡率时发生流型转变的位置相对于两相流平均速度将向下游蔓延 ;而高空泡率时则相对地向上游蔓延 ;空泡率很高时空泡率分布传播过程中将不会出现流型转变 .计算表明 :流型转变起始点的空泡率为 0 2 7,空泡率达到 0 5 8时流型转变终止 ;这与文献报告的气液两相流实验结果符合较好     

K-d tree based approach for point location problem in explicit model predictive control

Explicit Model Predictive Control (EMPC) produces control laws defined over a set of polyhedral regions in the state space, and the online computation of EMPC is to find the corresponding control law according to a given state by searching in a lookup table, called point location problem. This paper presents an approach of constructing a hybrid data structure called constructed k-d tree(CKDT), which combines the k-dimensional tree (k-d tree) with the binary search tree (BST) for point location in such polyhedral sets. To maintain a ‘full’ and balanced constructed tree the number of affine control laws is used as the basis for choosing the candidate hyperplanes (HPs) during the main construction process of CKDT, thus increasing offline efficiency by reducing the number of candidate HPs requiring computation. This methodology can be applied to the EMPC of high dimensional problems as the k-d tree – a main part of the CKDT approach - has already been successfully used to solve high dimensional problems in the field of computer science and engineering. The method involves a trade-off between memory storage requirement and online efficiency. A complexity analysis of the approach in the runtime and storage requirements is provided. The advantages of the method are supported by two examples in the paper.     

面向高维数据环境的个性化推荐质量控制模型研究

[目的/意义] 在高维数据环境下,推荐的精准度和实时性存在相互制约的现象。如何在精准度与实时性之间取得平衡,实现对推荐质量的有效控制是值得研究的问题。[方法/过程] 本文首先分析了高维数据环境的成因及其对推荐质量的影响,在此基础上构建了一种个性化推荐质量控制模型,该模型先评估推荐质量在精准度和实时性两个方面的损失,再结合应用环境,得到相应的质量控制策略。[结果/结论] 实验分析的结果证明该模型可以在高维数据环境下实现对推荐质量的有效控制,让推荐系统可以更好地适应不同的应用环境。     

政策目标与政策工具视角下湖北省大气污染防治政策内容分析

[目的/意义]对大气污染防治政策文本进行分析,为湖北省大气污染防治政策体系完善提供依据为目标。[方法/过程]引入内容分析方法,从政策工具、政策主题、政策利益相关者三个维度构建政策分析框架对湖北省大气污染防治政策展开研究。[结果/结论]2001—2018年间强制性政策占据了政策的绝大部分;政策主题结构较为单一,以机制建立类政策为主,预警与技术支撑类政策发展不足;政府在大气污染防治中扮演着主要角色;政策制定主体种类较少。维度协同分析结果表明,政策对政府的约束力度最强且存在较多政策空白。今后湖北省大气污染防治政策的制定要坚持政策工具运用的多元化,注重政策执行的协同化。     

网络舆情演化机理多维建模与仿真研究

[目的/意义]研究网络舆情演化的多维度模型,从更高视角解读网络舆情传播规律,丰富和完善网络舆情传播理论。[方法/过程]定量分析网络舆情趋势预测中信息增长率的变化问题,构建以增长率和时间为自变量,信息累计数量为因变量的多维函数模型,并通过MATLAB仿真研究各个参数对网络舆情传播的影响以及网络舆情传播路径分析,然后通过“成都女司机”微博数据验证了模型的可行性,更加直观地诠释了高维模型研究网络舆情演化机理的优势。[结论/结果]经过理论建模和实证分析得出,将logistic模型拓展到高维研究网络舆情演化机理是可行的,并且多维度模型很好地解释了网络舆情数据出现多个“峰值”现象,而网络舆情统计数据的实质是高维度模型曲线在时间轴的投影。