根箭图表示范畴中的Gorenstein平坦-余挠对象

设R是具有单位元的结合环,Q=(Q 0,Q 1,s,t)是箭图.给出根箭图表示范畴中的Gorenstein平坦-余挠对象的定义及等价刻画,并研究Gorenstein平坦-余挠对象的相关性质.

基于概率密度演化的输电塔-线体系抗风可靠性分析

以三线两塔直线段输电塔-线体系为工程对象,应用有限元数值模拟,建立了基于概率密度演化的输电塔-线体系抗风可靠性分析方法。首先,应用谱表示-降维方法模拟结构脉动风场,生成风荷载的代表性样本集合。然后,结合概率密度演化理论,分析了输电塔-线体系考虑气弹效应的随机动力反应。最后,应用等价极值思想构建了风荷载作用下输电塔-线体系失效准则,进而对输电塔-线体系的抗风可靠性进行精细化分析。本文结合谱表示-降维方法与概率密度演化理论,实现了仅用较少数量的代表性样本来精细地分析结构的抗风可靠性,为工程实践提供参考。

关于标准π-表示与π-同余类结构的研究

引进^∑上字α的逆序数r(α).利用这一概念及^∑上字的初等变换,对任何α∈^∑*,给出了一个得到π-同余类[α]π的标准π-表示的方法及若干有关π-同余类[α]π的结构的结果.

σ-弱本质有界函数和σ-弱可表示算子

本文引入了σ-弱本质有界算子函数及σ-弱可表示;证明了L(Ω,M)中的元素都能表示成Ω上的σ-弱可列可加算子测度,即存在等距映射将L(Ω,M)等距嵌入Ba(R)中。还刻画了L(Ω,M)上线性算子和线性泛函的性质;最后证明了L(Ω,μ)上算子T为σ-弱可表示算子的充要条件。

对《JJF1059-1999测量不确定度评定与表示》的初浅认识

通过学习计量技术规范《JJF10 5 9- 1999测量不确定度的评定与表示》我们体会到 ,该规范对理工科院校的教学培养目标有较强的适用性 ,规范对术语及概念的解释准确 ,不确定度的评定方法简便 。

基于随机函数-谱表示的高阶矩结构动力可靠度分析方法

基于随机函数-谱表示模型,提出了结构响应极值前四阶矩的计算方法 ,发展了非高斯随机激励下的结构动力可靠度分析的高阶矩方法:(1)修正了随机函数单个基本随机变量的离散点集表达式;(2)根据修正的离散点集生成少量的非高斯加速度时程样本并进行结构时程分析,从而估计得到结构响应极值的前四阶矩(均值、标准差、偏度、峰度);(3)提出了四阶矩可靠指标的完整表达,并应用于计算在非高斯随机激励下的结构动力可靠度。最后,以双自由度系统及八层框架结构的动力可靠度分析为算例,验证了本文方法的精确性与高效性:在样本数量明显减少的情形下,本文方法计算的前四阶矩与Monte Carlo模拟结果相比最大相对误差为5.54%,且动力可靠度分析结果几乎一致。

关于C~*-代数中Bohr不等式的一个注记（英文）

利用C*-代数到B(H)中的等距*-表示,研究C*-代数中的Bohr不等式,得到了4个推广的Bohr不等式成立的一些充分必要条件1.主要结论如下:设p,q∈R^+,且满足1/p+1/q=1,则A,B∈S(S为有单位元的C*-代数),|A-B|~2+|(1-p)A-B|~2≤p|A|~2+q|B|~2成立当且仅当p≤2;设α,β,u,v∈R,p,q∈R^+,则|αA+βB|~2+|uA+vB|~2≤p|A|~2+q|B|~2成立当且仅当p≥α~2+u^2,q≥β~2+v^2且(p-(α~2+u^2))(q-(β~2+v^2))≥(αβ+uv)~2;设a,b∈R^+,c∈C,则A,B∈S,a|A|~2+b|B|~2+cA*B+cB*A≥0成立当且仅当ab≥|c|2;设α,β∈R,x,y是正数,则A,B∈S,|αA+βB|~2≤x|A|~2+y|B|~2成立,当且仅当x≥α~2,y≥β~2且(x-α~2)(y-β)≥α~2β~2.

An Incremental Algorithm for Non-Slicing Floorplan Based on Corner Block List Representation

We present a novel incremental algorithm for non-slicing floorplans based on the corner block list representation. The horizontal and vertical adjacency graphs are derived from the packing of the initial floorplanning results. Based on the critical path and the accumulated slack distances we define,we choose the best position for insertion and do a series of operations incrementally, such as deleting modules, adding modules, and resizing modules quickly. This incremental floorplanning algorithm has a very high speed less than 1μm,which is one of the most important measures in this research. The algorithm preserves the original good performances on area and wire length. It can also supply other tools with good physical estimates for area, wire length, and other performance guidelines.

Ground-roll separation of seismic data based on morphological component analysis in twodimensional domain

Ground roll is an interference wave that severely degrades the signal-to-noise ratio of seismic data and affects its subsequent processing and interpretation.In this study,according to differences in morphological characteristics between ground roll and reflected waves,we use morphological component analysis based on two-dimensional dictionaries to separate ground roll and reflected waves.Because ground roll is characterized by lowfrequency,low-velocity,and dispersion,we select two-dimensional undecimated discrete wavelet transform as a sparse representation dictionary of ground roll.Because of a strong local correlation of the reflected wave,we select two-dimensional local discrete cosine transform as the sparse representation dictionary of reflected waves.A sparse representation model of seismic data is constructed based on a two-dimensional joint dictionary then a block coordinate relaxation algorithm is used to solve the model and decompose seismic record into reflected wave part and ground roll part.The good effects for the synthetic seismic data and application of real seismic data indicate that when using the model,strong-energy ground roll is considerably suppressed and the waveform of the reflected wave is effectively protected.

Concept-based approach for information retrieval

A concept-based approach is expected to resolve the word sense ambiguities in information retrieval and apply the semantic importance of the concepts, instead of the term frequency, to representing the contents of a document. Consequently, a formalized document framework is proposed. The document framework is used to express the meaning of a document with the concepts which are expressed by high semantic importance. The framework consists of two parts： the ＂domain＂ information and the ＂situation ＆ background＂ information of a document. A document-extracting algorithm and a two-stage smoothing method are also proposed. The quantification of the similarity between the query and the document framework depends on the smoothing method. The experiments on the TREC6 collection demonstrate the feasibility and effectiveness of the proposed approach in information retrieval tasks. The average recall level precision of the model using the proposed approach is about 10% higher than that of traditional ones.

Two-level Bregmanized method for image interpolation with graph regularized sparse coding

A two-level Bregmanized method with graph regularized sparse coding （TBGSC） is presented for image interpolation. The outer-level Bregman iterative procedure enforces the observation data constraints, while the inner-level Bregmanized method devotes to dictionary updating and sparse represention of small overlapping image patches. The introduced constraint of graph regularized sparse coding can capture local image features effectively, and consequently enables accurate reconstruction from highly undersampled partial data. Furthermore, modified sparse coding and simple dictionary updating applied in the inner minimization make the proposed algorithm converge within a relatively small number of iterations. Experimental results demonstrate that the proposed algorithm can effectively reconstruct images and it outperforms the current state-of-the-art approaches in terms of visual comparisons and quantitative measures.

Fractional S transform-Part 1:Theory

The S transform, which is a time-frequency representation known for its local spectral phase properties in signal processing, uniquely combines elements of wavelet transforms and the short-time Fourier transform （STFT）. The fractional Fourier transform is a tool for non-stationary signal analysis. In this paper, we define the concept of the fractional S transform （FRST） of a signal, based on the idea of the fractional Fourier transform （FRFT） and S transform （ST）, extend the S transform to the time-fractional frequency domain from the time- frequency domain to obtain the inverse transform, and study the FRST mathematical properties. The FRST, which has the advantages of FRFT and ST, can enhance the ST flexibility to process signals. Compared to the S transform, the FRST can effectively improve the signal time- frequency resolution capacity. Simulation results show that the proposed method is effective.

广义限制李超代数及其表示

定义了广义限制李超代数 ,证明了这一定义的三个等价条件 ,给出了广义限制李超代数的两个典型例子 。

A FORMAL REPRESENTATION FOR FEATURE-BASED DESIGN

Feature based design has been regarded as a promising approach for CAD/CAM integration.This paper aims to establish a domain independent representation formalism for feature based design in three aspects: formal representation,design process model and design algorithm.The implementing scheme and formal description of feature taxonomy,feature operator,feature model validation and feature transformation are given in the paper.The feature based design process model suited for either sequencial or concurrent engineering is proposed and its application to product structural design and process plan design is presented. Some general design algorithms for developing feature based design system are also addressed.The proposed scheme provides a formal methodology elementary for feature based design system development and operation in a structural way.

面向对象的家庭全息地图表示与构建

针对现代复杂而多样化的家庭环境,人对家庭服务机器人的服务需求,以及其自身基于家庭全息地图的路径规划的任务要求,借鉴人对空间环境的认知和地图的组建过程,提出了一种改进的面向对象的家庭服务机器人全息地图表示方法,设计出家庭-房间-物品三层表示模型。依据面向对象的思想,分别给出了改进的物品层、房间层和家庭层的面向对象表示方法。基于机器人自身携带的传感器对各层对象的空间数据进行采集。将该表示方法转化成可存储在数据库中的数据类型,将采集的数据存储到数据库中并对地图进行实时的更新。在家庭环境下,机器人基于该全息地图分别对各层进行对象识别和路径规划,实物实验说明基于家庭-房间-物品表示模型的家庭全息地图能满足服务机器人任务的需要。

“表示”的形式动词用法及其语法化

“表示”作为一个言说动词,要求宾语是一个意义完整的表述,一般由句子或者句群充当。一个表述可以压缩为一个谓词性短语,也可以只用一个谓词来概括。因此“表示”的宾语逐渐过渡为表征言语行为及情感态度的双音节及物动词,这种情况下的“表示”与典型形式动词有不容忽视的共性:语义虚化,句法上可以标记前置受事。“表示”能从言说动词逐渐虚化为形式动词是语法化的结果。“表示”以“副词+动词”为宾语时,一般被识解为定中而不是状中结构反映了“表示”动性增强,呈现出向形式动词靠拢的趋势。“表示”语法化的动因是满足书面语语体表达的需求。

整数对的低重量表示JSF_3(英文)

J.A.Solinas给出了整数对的最优带符号二进制表示,称做联合稀疏表示(JSF).JSF表示长度至多是最大整数的二进制长度加一,其平均汉明密度为1/2.利用窗口方法扩展了联合稀疏表示,给出了整数对的一种新表示方法:3-宽度联合稀疏表示(JSF3).该表示长度至多是最大整数的二进制长度加一,平均汉明密度为19/52.因此,利用JSF3计算uP+vQ比用JSF大约提高9%的效率.

基于改进型Kriging-HDMR的翼身融合水下滑翔机外形优化设计

为了使翼身融合水下滑翔机(BWBUG)具有更优的升阻特性,文中通过在优化过程中引入改善期望(EI)补点策略和移动中心点策略,对传统克里金-高维模型表示(Kriging-HDMR)优化方法进行了改进,以达到更准确的预测精度和更高效的优化效率。首先通过基于分类函数变换的参数化方法,建立BWBUG外形的参数化模型,然后以最大化升阻比为优化目标,采用改进型Kriging-HDMR优化方法,对BWBUG外形进行优化设计。试验结果表明,优化后BWBUG外形的升阻比比初始外形提高了3.135 6%。

约化C＊-代数自由积构造的注记

利用*-代数自由积上的GNS构造,给出C*-代数约化自由积的一种构造方法,证明此构造与Voiculescu所给出的C*-代数约化自由积的构造是等价的.

Logical-Structure Modeling for Conceptual Design

Based on the definition of a logic structure feature to relate logically functional requirements to geometric representation independent upon detailed geometric representation, this paper presents an idea of logical structure modeling for computer aided conceptual design and makes attempt to establish a representation formalism of logic structure modeling. The definition and representation of logical structure feature are given and an assembly module definition for supporting top down conceptual design is also proposed. The proposed scheme contributes to several aspects of conceptual design research, especially to provide elementarily a formal methodology for computer aided conceptual design system development and operation.