用好网上搜索引擎

简要介绍了网上搜索引擎的“目录分类检索”和“关键词检索”的正确使用方法。     

基于Internet的分布式设计知识资源检索策略

提出了一种快速、高效的两级知识检索方法：首先根据“加权关键词匹配定位法”来有效、准确地定位知识站点；然后“约束驱动知识检索”方法在所定位的知识站点中准确获取满足用户意愿的具体知识。两级知识检索方法可以改善原有传统检索方法的有效性，使设计开发人员在分布式知识资源环境下的知识检索效率大大提高。     

用程序方法实现“与或非”逻辑检索

“与或非”逻辑检索是一种方便灵活、功能强大的检索方式。一般的数据库管理系统都允许以逻辑检索表达式作为条件“输入”，但是目前还有许多情况是用高级语言（如C、COBOL、BASICA）编程，在这种情况下，就需要用户自己来实现这种功能。本文介绍了实现“与或非”逻辑检索的一种方法。     

一种基于感兴趣内容的图像检索方法

在基于内容图像检索研究中,针对如何提取用户感兴趣的内容以提高检索效果的问题,该文根据用户选择的相似图像自动获取“感兴趣”区域,使用Fisher判别进行区域中“感兴趣”特征分量阈值的动态选择,并以该“感兴趣”特征分量及“感兴趣”区域作为用户感兴趣的内容进行图像检索。试验结果表明了该方法的有效性。     

基于模糊关系的信息检索系统设计方法

传统的信息检索方法只能在“检索语”与“索引语”完全一致时有效,而无法解决二只有部分一致或意义相近时的信息检索。为此,利用模糊关系设计了信息检索系统,实验证明该方法可以把检索所需要的信息尽可能地查出;并给出每个信息的重要度,以便检索对信息进行舍取。     

商标检索中形状特征描述的研究

针对图像检索中的“语义鸿沟”问题,以商标图像为研究对象.分析了拉丁字母的物象、抽象和意象等含义,构建了一套“字母描述子”语言.同时还分析了商标的起源、构成和特征,并提出了用“字母描述子”对商标图像进行特征描述和编码的方法.经系列的检索结果和统计数据说明,用“字母描述子”对商标特征进行描述、编码和检索的方法具有一定的实用...     

中文专利侵权检索模型研究

结合中文专利权利要求的结构特征,首次将中文专利按照“分割词”重新分类,以重新划分的“新类别”进行词性选择,构造向量空间,设计了中文专利侵权检索模型,通过我国集成电路封装技术领域的发明专利进行技术侵权检索实证分析与对比实验,实验结果显示该模型的检索效果明显优于一般的侵权检索方法。     

基于相容粗糙集的图形图像信息预检索

早期的利用粗糙集理论进行信息检索都是以“等价粗糙集模型”为基础的，但是等价粗糙集的性质限制了该方法的应用范围，为此有些研究者提出以“相容粗糙集模型”代替“等价粗糙集模型”的新的信息检索的概念，此概念的关键在于“关键词的同时发生”和关于相容粗包含的“匹配算法”，提出了一种利用“相容粗糙集”的理论对图形图像进行预检索的新方法，即在相容类的近似空间里对图形图像进行预检索。为了验证这种新方法的有效性，在人脸图形和图像库中做了若干实验，实验结果表明，该方法可以有效地克服等价粗糙集在图形图像检索方面的限制，对提高图形图像的检索效率具有一定的作用。     

基于模糊关系的信息检索系统设计方法

传统的信息检索方法只能在“检索语”与“索引语”完全一致时有效,而无法解决二者只有部分一致或意义相近时的信息检索.为此,利用模糊关系设计了信息检索系统,实验证明该方法可以把检索者所需要的信息尽可能地查出;并给出每个信息的重要度,以便检索者对信息进行舍取.     

一种压缩域特征提取与语义图像检索技术

为了解决“语义鸿沟”问题，通过将隐含语义索引(LSI)技术引入到图像语义提取问题的研究中，试图从图像的视觉特征中抽取出“高层概念”．基于GM(1，1)压缩域中的一种图像特征，提出了一种建立“图像视觉特征”与“语义信息”之间映射的技术方法．实验研究表明，这种基于压缩域特征和LSI技术的图像检索方法能显著改善图像检索的性能，提高图像检索的质量．     

A Simulation Model of the Price Bargaining Rules in Vertical Relationships

This paper analyzes the dynamics of the price and quantity bargaining betweenfour agents, in a current industrial structure, with a special attention tothe price bargaining. The structure combines a bilateral monopoly in a marketfor inputs, and a duopoly in a final market. After a simplified presentationof a model which proposes equilibrium solutions to the bargaining, we presentthe protocol and the results of an experiment whose objective is twofold. Thefirst one is to test the assumptions of the model. The second one is toidentify behavioral models and bargaining rules for a work of simulation. Theexperimental results do not confirm the solutions of the theoretical model,which predicted a Nash solution for the price bargaining, and used the cournotconjecture in the quantity bargaining. A detailed analysis of the resultsleads to some observations useful to parameterize a simulation model. Thesimulation runs a systematic analysis of the dynamics of the bargaining rulesin this structure.     

A case study of a difficult refinement: a fast dictionary for a spell-checking program

We present a difficult refinement of a dictionary for a spell-checker. It represents a realistic problem and shows how a calculational approach using a relation known as a coupling invariant can improve the process of refinement over the conventional posit-and-prove approach. The paper concludes with a brief discussion of the advantages of the approach we adopt. We also hope that the paper will contribute a difficult refinement to the rather sparse corpus of such case studies in the literature—especially those using the calculational approach.     

The importance of introducing a waiting time for Lattice Monte Carlo simulations of a polymer translocation process

For a standard Lattice Monte Carlo (LMC) simulation of a random walker subject to a bias, it is impossible to obtain both a correct mean velocity and diffusion coefficient. To correct this, a modified LMC algorithm has been developed where the introduction of a probability of remaining in the current state allows for a distribution of intervals between jumps. In this paper, we demonstrate the impact of this modification for a first-passage problem: the translocation of a polymer through a nanopore. We find that while either approach yields the correct mean first-passage time, the incorporation of a waiting time is necessary to obtain the correct spread of times.     

A path following problem for a class of non-holonomic control systems with noise

This paper deals with a path following problem for a system affected by noise and proposes a dynamic inversion-based controller that makes use of the error between the real position and a suitable path location. An estimate of such error is given in terms of the noise bounds, showing the practical stability of the closed loop system. The results presented in this article apply to a subclass of Chaplygin control systems which includes several common mechanical systems. As an example the developed strategy has been applied to maneuver a kinematic model of a system moving in a 3-dimensional space in such a way that a point located at a positive distance from its center of geometry is driven towards a given path.     

Reliability analysis of a repairable duplex system

We analyse the survival time of a repairable duplex system characterised by cold standby and by a pre-emptive priority rule. We allow general probability distributions for failure and repair. Moreover, an important realistic feature of the system is the general assumption that the non-priority unit has a memory. This combination of features has not been analysed in the previous literature. Our (new) methodology is based on a concatenation of a Cauchy-type integral representation of the modified Heaviside unit-step function and a two-sided stochastic inequality. Finally, we introduce a security interval related to a security level and a suitable risk-criterion based on the survival function of the system. As a practical application, we analyse some particular cases of the survival function jointly with the security interval corresponding to a security level of 90.     

A simulation-based heuristic algorithm for disposition of direction finders

A direction finder is a military weapon that is used to find locations of targets that emit radio frequencies. Multiple direction finders are used in a direction finder system for finding locations of targets in an area of interest. We present a two-stage heuristic algorithm for disposing direction finders in a direction finder system for the objective of maximizing the accuracy of estimation of the location of a target that is assumed to be located in the area of interest. In the suggested heuristic algorithm, a simulation-based method is used for estimating the probability of coverage, the probability that a target is in a given region (of a given size) surrounding the estimated location of the target, and another simulation-based method and a local search method are used to determine locations of direction finders that result in the maximum probability of coverage. Performance of the suggested algorithm is evaluated through computational experiments and results show that the algorithm gives a good disposition plan in a reasonable amount of computation time.     

The conversion of a dynamic B-spline curve into piecewise polynomials in power form

The evaluation of points and the computations of inflection points or cusps on a curve are often necessary in CAGD applications. When a curve is represented in a B-spline form, such computations can be made easier once it is transformed into a set of piecewise polynomial curves in power form. The usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in power form is done either by a knot refinement followed by basis conversions, or by applying a Taylor expansion on each knot span of a B-spline curve.Presented in this paper is a new algorithm to convert a B-spline curve into a set of piecewise polynomial curves in power form. Experiment shows that the proposed algorithm significantly outperforms the conventional approach when one or more control points of a B-spline curve are continuously moving.     

Learning criterion and inductive behaviour

Inductive behaviours may be classified according to their aim. We intend to show that there are at least two kinds of inductive behaviours. Most of the publications seem to take into consideration only one of these: to copy as exactly as possible the behaviour of a probability process. After a brief discussion to explain the necessity of a learning criterion and a recall about one criterion, representative of most of them, we shall define a new criterion, and show why it is better fitted to learn the laws of a deterministic process from a set of observations.This criterion has been used to implement a program which builds an acceptor of natural language sentences in a CAI environment using a tutorial strategy, and then for a question answering device. As attractive as the results are, their improvement requires a semantic model. We give the basic principles of a model which we currently develop, and whose main feature is approximation.     

Curvature weighted gradient based shape orientation

Determining the orientation of a shape is a common task in many image processing applications. It is usually part of the image preprocessing stages and further processing may rely on an adequate method to determine the orientation. There are several methods for computing the orientation of a shape, each of them with its own strengths and weaknesses; a method which performs outstandingly for one application may have a poor performance for a different application. In this paper we present a new method for computing shape orientation based on the projection of the tangent vectors of a shape onto a line and weighting them using a function of the curvature. Some of the results from ?uni? (2008) [14] are particular cases of the results presented here.