Γ-左群的分解

引入了Γ 左零半群和Γ 左群的概念。讨论了Γ 左群的一些性质。利用Γ 群 ,给出了Γ 左群的分解 ,证明了Γ 半群M是Γ 左群当且仅当M是Γ 群的Γ 左零带     

Г—纯整半群

印度数学家Ｍ．Ｋ．Ｓｅｎ和Ｎ．Ｋ．Ｓａｈａ在１９８６年给出了Г－半群的概念和讨论了Г－半群的若干性质。本文引入了Г－正则半群和Г－纯整半群的概念。     

左阿基米德序半群的自然序带

刻划了分别可分解为左阿基米德序半群，左单序半群的幂零拆张序半群和左单序半群的自然序带的序半群的特征。     

A Koszul Decomposition for the Computation of Linear Syzygies

In the present paper some algorithms are proposed for computing Linear Strands and Betti Numbers of graded modules over polynomial rings. These algorithms are based on a block-decomposition, induced by the Koszul syzygies, of the linear systems involved with the Hilbert's method for computing syzygies. Some further optimizations are suggested and applied by the authors to an implementation they have developed of the algorithms. Received: January 10, 2000; revised version: July 17, 2000     

有关AMBN热分解特征的研究

该文用蓄热贮存试验法测定了自反应性物质ＡＭＢＮ试样从试样进入恒温箱到发生热爆炸过程中温温度（Ｔ）随时间（ｔ）的变化曲线；描述和解释了Ｔ－ｔ曲线的变化特点和ＡＭＢＮ试样的热分解、熔解及熔点下降之间的关系，并指出当ＡＭＢＮ试样受热后呈固－液两相共存和熔点下降时，预示着试样将发生自加速反应。     

3A型分子筛对四氢呋喃水合物分解的影响

在常压下,将粉碎并筛分后的成型3A分子筛粉加入四氢呋喃-水（二者质量比为19：81）体系中,然后将体系温度从室温降低到零下5度,等水合物形成后将体系温度回升,用显微镜观察四氢呋喃水合物的生成及分解过程,并与未加3A分子筛的体系进行比较。结果发现,THF水合物的分解过程可以分为大概2个阶段,即客体分子脱离区和晶体分解区;同时,3A分子筛的加入能够显著降低四氢呋喃水合物的分解温度,降低的幅度约为0．6℃。     

A Decomposition of Total Variation Depth for Understanding Functional Outliers

Abstract

There has been extensive work on data depth-based methods for robust multivariate data analysis. Recent developments have moved to infinite-dimensional objects, such as functional data. In this work, we propose a notion of depth, the total variation depth, for functional data, which has many desirable features and is well suited for outlier detection. The proposed depth is in the form of an integral of a univariate depth function. We show that the novel formation of the total variation depth leads to useful decomposition associated with shape and magnitude outlyingness of functional data. Compared to magnitude outliers, shape outliers are often masked among the rest of samples and more difficult to identify. We then further develop an effective procedure and visualization tools for detecting both types of outliers, while naturally accounting for the correlation in functional data. The outlier detection performance is investigated through simulations under various outlier models. Finally, the proposed methodology is demonstrated using real datasets of curves, images, and video frames.     

A Decomposition Strategy for the Variational Inference of Complex Systems

Markov chain Monte Carlo approaches have been widely used for Bayesian inference. The drawback of these methods is that they can be computationally prohibitive especially when complex models are analyzed. In such cases, variational methods may provide an efficient and attractive alternative. However, the variational methods reported to date are applicable to relatively simple models and most are based on a factorized approximation to the posterior distribution. Here, we propose a variational approach that is capable of handling models that consist of a system of differential-algebraic equations and whose posterior approximation can be represented by a multivariate distribution. Under the proposed approach, the solution of the variational inference problem is decomposed into three steps: a maximum a posteriori optimization, which is facilitated by using an orthogonal collocation approach, a preprocessing step, which is based on the estimation of the eigenvectors of the posterior covariance matrix, and an expected propagation optimization problem. To tackle multivariate integration, we employ quadratures derived from the Smolyak rule (sparse grids). Examples are reported to elucidate the advantages and limitations of the proposed methodology. The results are compared to the solutions obtained from a Markov chain Monte Carlo approach. It is demonstrated that significant computational savings can be gained using the proposed approach. This article has supplementary material online.     

Task Decomposition in Cut-Off Dimensioning: A Frame-Based Model

The cut-off dimensioning problem is characterized by the complexity of the problem, and by environmental uncertainty. A solution is proposed using deeomposition into lateral modules and vertical layers Lateral decomposition permits the distribution of expertise, hence the reduction in the complexity of the problem. The vertical decomposition permits greater expert decision-making, hence the reduction in uncertainty. A synergy of three knowledge representation methods is used: Declarative knowledge is used for rule-based reasoning, heuristic methodologies are used for the deterministic, context-dependent decision-making, and strictly algorithmic procedures are used for the tasks inclined to data abstraction and mathematical manipulations. The frame is used as the common knowledge carrier among all three tasks.     

商品房购房群体市场细分研究

目的：将人口统计学变量与生活方式变量结合起来对商品房购房群体进行市场细分研究。方法：采用深度访谈法及问卷法,对北京市商品房购房群体特征及购买偏好进行调查。结果：将商品房购房群体通过生活方式变量划分为四个细分群体,工作积极群、社交休闲群、家庭自我群、中庸理性群。结论：商品房购房群体特点倾向于年龄较大,职业偏向于中高层管理人员且家庭收入较高,家庭状况为已婚。不同细分群体购房者在人口统计变量以及商品房购买偏好中有显著差异。     

合金调幅分解与有序化共存的图形热力学分析

经典固溶体理论认的调幅分解与有序化两种失稳模式不可能在同一合金系中同时出现，但许多合金中都发现了这一现象。本文通过构造的多种热力学图形，直观地解释了共存现象，从理论上证实了调幅分解与有序化共存反应的可能性。     

Decomposition of perceived usefulness: A theoretical perspective and empirical test

Information technology (IT) research largely treats perceived usefulness as a simple concept reflecting system effectiveness in improving task productivity. In the context of continuing use of modern IS – complex systems capable of supporting various uses – this approach is overly simplistic. This simplicity negatively affects content validity of the key determinants of IT use, thereby biasing research findings and conclusions. This study applies affordance theory integrated with uses and gratifications to conceptualize the factor of usefulness as a multidimensional construct accounting for the complexity of modern IT. This perspective is empirically tested using a cross-sectional survey sample of 218 university-student Facebook users. The results of the analysis affirm that the proposed conceptualization of perceived usefulness is valid. The study contributes by depicting the mechanism by which usefulness beliefs shape users’ decisions, and by demonstrating that using a multidimensional approach to measure conceptually complex constructs can lead to more accurate prediction and explanation of IT usage.     

振动载荷识别的奇异值分解法

本文采用奇异值分解技术处理载荷识别方程组系数矩阵的病态问题,并将这一技术应用于某机平尾的地面振动载荷识别,得到了令人满意的结果,为该机平尾的飞行载荷识别提供了有关技术和经验。