An investigation of modal structures as an alternative semantic basis for epistemic logics

In the past, Kripke structures have been used to specify the semantic theory of various modal logics. More recently, modal structures have been developed as an alternative to Kripke structures for providing the semantics of such logics. While these approaches are equivalent in a certain sense, it has been argued that modal structures provide a more appropriate basis for representing the modal notions of knowledge and belief. Since these notions, rather than the traditional notions of necessity and possibility, are of particular interest to artificial intelligence, it is of interest to examine the applicability and versatility of these structures. This paper presents an investigation of modal structures by examining how they may be extended to account for generalizations of Kripke structures. To begin with, we present an alternative formulation of modal structures in terms of trees; this formulation emphasizes the relation between Kripke structures and modal structures, by showing how the latter may be obtained from the former by means of a three-step transformation. Following this, we show how modal structures may be extended to represent generalizations of possible worlds, and to represent generalizations of accessibility between possible worlds. Lastly, we show how modal structures may be used in the case of a full first-order system. In all cases, the extensions are shown to be equivalent to the corresponding extension of Kripke structures.     

数学领域集体词结构形式化处理研究

根据数学领域自然语言理解的特点,结合集合论的思想深入分析了集体词结构。集体词结构是表示一个可数的集体概念,其外延是一个事物类。集体词结构较好地解决了数学领域中的数量词结构的形式化处理问题。首先给出了集体词结构的语义认知基础,并采用基于知识的方法,应用本体论思想,构造了系统的集体词结构模型。然后对集体词结构的群体关系进行分类和介绍。这种集体词结构的处理方法在数学领域智能辅导领域中得到了较好的应用。     

混凝土结构温度内力数值分析

为研究混凝土结构的温度效应,利用ANSYS对混凝土框架、框架-剪力墙和剪力墙等结构在温度变化作用下的变形特点和内力分布规律进行系统分析.对具有不同纵向长度、楼层数和建筑体形特征的结构分别建立计算模型,在假设建筑物内外无温差和有温差两种温变条件下进行计算分析,从中得到各种结构温度变形和内力分布的基本规律,其主要结论对结构工程师具有实用价值.     

The effect of the microfluidic diodicity on the efficiency of valve-less rectification micropumps using Lattice Boltzmann Method

The efficiency of the valve-less rectification micropump depends primarily on the microfluidic diodicity (the ratio of the backward pressure drop to the forward pressure drop). In this study, different rectifying structures, including the conventional structures (nozzle/diffuser and Tesla structures), were investigated at very low Reynolds numbers (between 0.2 and 60). The rectifying structures were characterized with respect to their design, and a numerical approach was illustrated to calculate the diodicity for the rectifying structures. In this study, the microfluidic diodicity was evaluated numerically for different rectifying structures including half circle, semicircle, heart, triangle, bifurcation, nozzle/diffuser, and Tesla structures. The Lattice Boltzmann Method (LBM) was utilized as a numerical method to simulate the fluid flow in the microscale. The results suggest that at very low Reynolds number flow, rectification and multifunction micropumping may be achievable by using a number of the presented structures. The results for the conventional structures agree with the reported results.     

Knowledge structures in a knowledge base

Rough set theory is a useful tool for dealing with imprecise knowledge. One of the advantages of rough set theory is the fact that an unknown target concept can be approximately characterized by existing knowledge structures in a knowledge base. This paper explores knowledge structures in a knowledge base. Knowledge structures in a knowledge base are firstly described by means of set vectors and relationships between knowledge structures divided into four classes. Then, properties of knowledge structures are discussed. Finally, group, lattice, mapping, and soft characterizations of knowledge structures are given.     

度量空间中高维索引结构回顾

1 引言近年来,高维数据库的应用得到快速的发展,如海量的多媒体数据库、大规模的文本数据以及生物信息学中庞大的DNA数据库等,这些信息一般使用特征抽取等方法映射为高维数据,然后通过计算这些高维数据之间距离实现相似性查询。例如,对于图像数据,往往采用颜色直方图来表征一幅图像,当需要从数据集查找与给定图像相似的图像时,通过计算     

Recent developments in the theory of data structures

This paper surveys some of the recent theoretical work on data structures. Work employing abstract graph models is covered as well as work on specific structures such as arrays and string patterns. Also included is work treating algorithms on complex structures and proving properties of programs that manipulate such structures. The paper concludes with a section on results using program schemata models to compare the utility of various data structures.     

谈话节目语料库的构建与会话结构分析

口语语料库的建设是口语研究的基础工作,该文选择具有代表性的交谈式谈话节目《锵锵三人行》和对谈式谈话节目《鲁豫有约》作为语料,建立了一个小型的谈话节目语料库,并构建了包含五大类16小类的会话结构标注体系,对语料进行了会话结构的标注。统计得到打断结构309例,插入结构141例,重复结构111例,问答结构653/589例,阻碍—修正结构51/21例,反映了会话结构在数量上的不均衡分布,节目的形式、性质以及交际任务是会话结构分布的主要影响因素。会话结构组合具有模式性,该文使用Trigram方法对其组合情况进行了分析,发现语料中的高频组合是问答毗邻对,此外有大量的非毗邻性组合。会话结构组合模式不但反映出谈话节目的风格特点,还有助于分析会话中的功能性模块、会话策略的形成,进而更加深入地了解会话的运作机制。     

Systolic structures: A notion and characterization

A notion of systolicity based on embeddability of processing structures is introduced. This notion characterizes the systolic structures that can be extended to solve problems of larger size, without a corresponding increase in processing time. A mathematical model for specifying such extendable structures is developed. The extensions of these structures are specified by extension rules using wavefronts and interconnection functions. An approach to deriving the algorithm schema corresponding to the computation performed by extendable structures is discussed. A simple necessary and sufficient condition for the systolicity of these structures is finally established.     

Homogeneous digital analogous structures with programmable cojxutation

Homogeneous digital analogous structures intended for solving a broad class of simulation are worked out. The above-mentioned simulating structures consist of processors and homogeneous commutation register structures. Each processor can be rearranged for solving some enormous operations. Commutation structures form commutation channels between the processors.     

紧凑型电磁带隙结构的设计方法分析

为了在有限空间放置能够起作用的电磁带隙结构数量,必须减小电磁带隙结构的尺寸。针对此问题,总结了电磁带隙结构两种类型的带隙形成的物理机理,根据带隙形成机理给出了设计小型化紧凑电磁带隙结构的思路,并依据此思路设计了一种紧凑型电磁带隙结构。仿真结果表明,新电磁带隙结构在中心频率3.28GHz处得到了900MHz的禁带宽度,相对带宽达到27.4%。     

Multi-structure docking analysis of BACE1 crystal structures and non-peptidic ligands

In order to design novel non-peptidic inhibitors of BACE1, many research groups have attempted using computational studies including docking analyses. Since there are too many 3D structures for BACE1 in the protein database, the selection of suitable crystal structures is a key prerequisite for the successful application of molecular docking. We employed a multi-structure docking protocol. In which 615 ligands’ structures were docked into 150 BACE1 structures. The large number of the resultant docking scores were post-processed by different data analysis methods including exploratory data analysis, regression analysis and discriminant analysis. It was found that using one crystal structure for docking did not result in high accuracy for predicting activity of the BACE1 inhibitors. Instead, using of the multi-structural docking scores, post-processed by chemometrics methods arrived to highly accurate predictive models. In this regards, the PDB accession codes of 4B70, 4DVF and 2WEZ could discriminate between active and inactive compounds, with higher accuracy. Clustering of the BACE1 structures based on principal component analysis of the crystallographic structures the revealed that the discriminant structures are in the center of the clusters. Thus, these structures can be selected as predominant crystal structures for docking studies of non-peptidic BACE1 inhibitors.     

面向无线自组网的交叠分簇网络结构及性能分析

无线自组网常常采用分簇网络结构来改善网络性能,并且大都是非交叠分簇结构.首先,比较了交叠分簇结构和非交叠分簇结构的优缺点.然后,重点对交叠分簇网络结构的特性进行了研究,特别考虑了相邻簇之间的高效通信问题.最后,通过模拟实验分析了交叠分簇策略下几种典型分簇算法的性能,验证了算法的有效性.     

图像序列的多通道围线结构匹配

本文对于运动图像序列提出了基于多通道围线结构的匹配,根据一对运动图像和n个通道中的n对卷积图,建立了多通道围线结构,然后利用这些结构所具有的良好性质,分层次地实现匹配。实验表明:本算法对于真实场景下多物体运动的处理,表现出令人满意的简单性、精确性、稳定性和实时性。     

Lagrangian Coherent Structures with Guaranteed Material Separation

Given an unsteady flow field, one common way to compute Lagrangian Coherent Structures (LCS) is to extract extremal structures of the Finite Time Lyapunov Exponent (FTLE). Experience has shown that the resulting structures are often close to material structures (i.e., material lines or material surfaces). Moreover, it has been proven that for an integration time converging to infinity, they converge to exact material structures. However, due to the finite integration time in FTLE, they are generally not exact material structures. In this paper we introduce a modification of the FTLE method which is guaranteed to produce separating material structures as features of a scalar field. We achieve this by incorporating the complete available integration time both in forward and backward direction, and by choosing an appropriate definition for separating structures. We apply our method to two test data sets and show the differences to classical FTLE.     

On the mathematics of higher structures

In a series of papers, we have discussed higher structures in science in general, and developed a framework called hyperstructures for describing and working with higher structures. We discussed the philosophy behind higher structures and formulated a principle in six stages – the Hyperstructure Principle – for forming higher structures. In this paper, we will relate hyperstructures and the general principle to known mathematical structures. We also discuss how they may give rise to new mathematical structures and prepare a framework for a mathematical theory.     

利用扩展标记集的词结构分析

该文给出了一种与传统分词不同的词法分析选择,提出了一种利用扩展标记集来实现词内部结构分析的方法。首先阐述了词的内部结构特点,把结构中的前后缀视为特殊的词,进而通过识别出每一个词的前后缀来识别词的内部结构。方法是把词内部结构识别问题转换成序列标注问题,通过扩展标记集,采用CRF模型来实现词的内部结构分析。最终实验表明,无论是在总体性能上,还是在各层结构的识别上都取得了较高的准确度。     

空间剖分树形查找结构的效率分析

空间剖分是构造快速空间查找数据结构的有效方法,四叉树、八叉树、Kd-树是典型的基于空间剖分思想的树形空间查找结构。选择合适的参数来构造实际点集数据的树形查找结构,对提高相关算法的效率具有重要意义。在分析三种树形查找结构基本原理的基础上,通过构造具有不同空间分布特征的实验数据,设置不同的树形空间剖分结构参数,来分析三种结构支持下搜索算法的时间消耗,确定使查找效率达到最优的树形结构构造参数。相关研究结论对于优化空间剖分树形查找结构的效率、提高相关算法的性能等,有一定的参考价值。     

A rational reconstruction of the domain of feature structures

Feature structures are employed in various forms in many areas of linguistics. Informally, one can picture a feature structure as a sort of tree decorated with information about constraints requiring that specific subtrees be identical (isomorphic). Here I show that this informal picture of feature structures can be used to characterize exactly the class of feature structures under their usual subsumption ordering. Furthermore, once a precise definition of tree is fixed, this characterization makes use only of standard domain-theoretic notions regarding the information borne by elements in a domain, thus removing (or better, explaining) all apparentlyad hoc choices in the original definition of feature structures. In addition, I show how this characterization can be parameterized in order to yield similar characterizations of various different notions of feature structure, including acyclic structures, structures with appropriateness conditions and structures with apartness conditions (used to model path inequations). The generalizations to other notions of feature structure also emphasize that the construction given here is in fact independent of the application to feature structures.This research has been supported by the Deutsche Forschungsgemeinschaft as part of Sonderforschungsbereich 314, Projekt N3.     

制造系统控制结构现状和发展——从集中结构到动态结构

系统的决策控制系统依赖于系统内部的控制结构,制造系统的控制结构是先进制造与自动化领域的重要研究课题。制造系统的控制结构与计算机技术、生产设备自动化水平及制造模式等因素有关。早期的制造系统采用集中控制结构,而柔性制造系统和计算机集成制造系统多采用递阶控制结构。目前制造业已进入一个新时代,传统生产模式和企业结构无法适应不可预测的激烈的环境变化。因此,未来制造系统需要具备快速变化能力的动态控制结构。