首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 171 毫秒
1.
文本的生成模型是基于文本向量空间表示基础上,针对文本数据的概率表示,针对文本的产生过程进行统计建模的方法。生成模型的优势在于在准确描述表示文本的前提下,达到提高文本挖掘效率的目的。同时,根植于概率统计的生成模型,拥有一整套用于模型学习、推论、模型比较、选择的理论和方法,是其他非统计方法所无法比拟的。本文介绍了用于描述可交换的离散数据集合主要的几种概率生成模型,在向量空间表示的基础上能够捕捉不同程度的词与词之间的上下文(主题)依赖性,因而在英文文本的挖掘上得到了一定程度的应用和肯定。  相似文献   

2.
《价值工程》2013,(23):235-236
粒子群优化算法是由Kennedy和Eberhart[1,2]在1995年提出的一种基于群体智能的随机进化算法,是在鸟群、鱼群和人类社会行为规律的启发下提出来的。针对粒子群优化算法容易陷入局部极小的缺陷,对粒子群优化算法的速度进化公式进行改进,将粒粒子行为基于个体极值和全局极值变化为基于个体极值的加权平均、全局极值和按概率选择其它粒子的个体极值。新算法更符合生物的学习规律,使得粒子充分利用整个种群的信息,保证了群体的多样性。  相似文献   

3.
医院的会计与统计属于医院经济管理信息系统 ,在 2 1世纪的今天 ,医院将面临各种新情况、新问题和新要求 ,医院的各项经济活动、各种经济信息、业绩分析评价、目标落实的措施、内部考核的各种数据等等 ,都与会计与统计有着紧密的联系 ,都要求会计与统计在管理上与之相适应。笔者试从二者的结合上谈谈自己的认识和看法。一、会计与统计在理论上的有机结合了解会计与统计的渊源关系的过程 ,我们可以发现 ,人类起初的统计行为 ,大体上是与会计行为同时产生的。在进入古代文明社会之后 ,统计工作又是“大会计”范畴中的一个组成部分 ,会计、统计…  相似文献   

4.
传统的系统防御方法是基于特征库的被动防御,它们无法实时发现零日攻击。本文基于隐马尔科夫模型建立描述系统CPU行为的模型。该方法根据系统用户的行为习惯动态调整模型参数,利用观测序列相对于代表正常行为轮廓的模型的似然概率衡量系统CPU行为的正常度。由于该方法不需要特征库,可以更有效地应用于未知主机威胁的早期检测。  相似文献   

5.
龚娟萍 《中外企业家》2013,(8Z):203-203
无论是认识自然还是认识人类社会都离不开统计,统计研究社会现象数量方面必须运用马列主义哲学关于质与量的辩证关系和必然性与偶然性的辩证关系,来认识社会现象的本质及其规律性。  相似文献   

6.
杜娟  邵盈盈  李利杰 《价值工程》2010,29(7):145-146
垃圾邮件日益蔓延,引起全世界的广泛关注,研究基于内容过滤的反垃圾邮件技术,主要包括基于原则评分和基于概率统计的方法,并进行系统的设计和实现,最后,在实验中通过采用K次交叉的验证方法,得到系统的评价指标,并证明了系统的有效性。  相似文献   

7.
彩票与概率统计有着千丝万缕的联系,这是数学学科与社会生活实践相联系的一大典型。文章通过阐述概率统计、彩票的具体情况,分析概率统计在彩票中的应用依据,对概率统计在彩票中的应用展开探讨,旨在为如何促进概率统计在彩票中的科学合理应用研究提供一些思路。  相似文献   

8.
骞龙江 《价值工程》2011,30(22):186-187
在中学数学进行大幅度的改革后,随着概率统计向高中数学的下方,工程数学如何适应中学数学改革与社会进步的要求,改革概率统计教学、课程体系,是工程数学教育必须直面的一个问题。文章探讨了高中数学课改的影响,分析了目前概率统计教育与中学数学课改不相适应的现状,分析了目前招收的学生普遍认为概率统计比较难学原因,提出了概率统计教育改革的内容与目标。  相似文献   

9.
芮同林  赵锦 《价值工程》2015,(5):303-305
维修性是产品使用阶段的设计属性,维修性好坏直接影响到产品的持续使用能力。产品维修性验证需要通过特定试验进行,本文基于概率统计的方法,论述了产品维修性试验开展的理论基础,并在某型产品维修性试验中进行了验证。  相似文献   

10.
蒙特卡罗方法在核类本科专业的教学初探   总被引:1,自引:0,他引:1  
向东  李小华  王振华  宋碧英 《价值工程》2010,29(29):182-183
蒙特卡罗方法是以概率统计理论为基础、通过计算机编程而实现的一种数值计算方法,在核科学与技术等领域有着广泛的应用。新时期下,初步尝试面向核类本科专业开设蒙特卡罗方法这门课程,将概率统计思想和编程实践训练融入到蒙特卡罗方法教学中,教学取得了一定成效。  相似文献   

11.
The theory of probability employs a deductive method of thinking which traces effect from cause. Statistics uses an inductive method of thinking and tries to trace cause from effect. This noble goal can be successfully achieved if and only if a researcher deals with a homogeneous data set. A homogeneous data set is generated logically and then it is to be tested statistically. The homogeneity principle bridges the gap between probability theory and applied statistics and makes statistics as precise as the theory of probability. In this role statistics opens new horizons for estimating parameters when the central limit theorem is not applied.  相似文献   

12.
We propose that the process of abduction is a useful tool for how management scholars can better develop new explanatory hypotheses and theories. In doing so, we differentiate abduction from the more commonly studied methods of deduction and induction. We briefly explain the various research streams on abductive reasoning and propose a version that is focused more on the process of abductive reasoning and less on the outcomes. We argue that by using contrastive reasoning and by recognizing different triggers of abduction, this process can help guide researchers to the types of causal explanations that are interesting. We conclude with some examples of abduction in the history of management research and a discussion of features of the reasoning processes involved.  相似文献   

13.
Si studia una nozione di riassunto esaustivo, che diremo a fini predittivi e che è già stata oggetto d'indagine da parte di F. Spizzichino sotto diversa denominazione. Si pone in evidenza la naturalezza di questa nuova definizione che, senza alcuna restrizione, può essere applicata in ogni tipo di ragionamento induttivo. Nella prima parte della ricerca, dopo alcune esemplificazioni sull'applicazione in alcuni tipici problemi inferenziali con particolare riguardo alla costruzione di modelli ipotetici a partire da considerazioni squisitamente predittive del concentto di riassunto esaustivo a fini predittivi, se ne studiano le principali proprietà. Nella seconda parte (che apparirà in un prossimo numero di questa Rivista) se ne analizzeranno i rapporti con le più abituali nozioni di riassunto esaustivo.
In this paper (first part of a wider work; the second part will appear in the next issue of this journal) we support the idea that the major objective of inductive reasoning is the distribution for outcomes of any sample not jet observed (predictive distribution) Parameters are a secondary device that can ultimately be justified and can lend some simplification.According to this point of view, we study a notion of prediction sufficiency introduced by F. Spizzichino (1978). Many of the results true for classical sufficient statistics apply to our predictive sufficient statistics as we demonstrate in Section 3.In the second part we analyse sequences of predictive sufficient statistics and their relations with classical sufficient statistics for the parameters which are limits of these sequences. The examples of Section 2 represent a first limited approach to this problem.


Lavoro eseguito nell'ambito del GNAFA-CNR.  相似文献   

14.
薛凤  张利凤 《价值工程》2012,31(3):239-240
独立学院作为我国高等教育大众化的产物,是一种新的办学模式。开拓独具特色的"应用型人才培养"模式是三本院校持续发展的保障。而概率论与数理统计作为应用性广泛的数学分支是一门重要的基础课程,那么对当前三本院校的概率论与数理统计如何改革,才能既符合独立学院的办学模式。探索一些改革措施,对提高教学质量具有重要的意义。文章从教学方法,教学内容,教学结构以及教材选取等多方面探讨了独立学院概率论与数理统计的改革。  相似文献   

15.
微观交通仿真技术是解决城市交通网络拥塞问题的有效工具,情感是人类具有智能的一个重要体现,然而如何通过情感来提高Agent的智能性已成为亟待解决的关键问题。文章结合生理和认知对情感的影响,提出了情感计算的建模方法,建立与Agent相结合的情感结构,以产生具体、真实的情感行为。  相似文献   

16.
This paper discusses the uses of computer algebra within statistics and probability. A distinction is drawn between the use of computer algebra packages to support investigations, by performing calculations, ankl their use to implement structure; to build in elements of a theory (such as stochastic calculus or the Taylor string theory of Barndorff Nielsen and others) as a preliminary to research investigations. Brief surveys are given of instances in the literature of use of computer algebra in probability and statistics. Two examples of implementations of structure are discussed, both drawn from the author's own work with the computer algebra package REDUCE. One is a simple demonstration using moments of the Poisson distribution. The other is itovsn3 , an implementation of the semimartingale stochastic calculus. It is described how itovsn3 may be used to derive the characteristic function of the Lévy stochastic area, following a proof due to S. Janson. Prospects for future work and for work in progress are discussed.  相似文献   

17.
Two studies were carried out to analyze whether learning technical drawing improves a person’s ability for spatial visualization. Visualization and inductive reasoning tests were applied at the beginning and end of a course in technical drawing in samples of first year engineering students. In both studies it was observed that a moderate percentage of students improved their Visualization test execution. The improvement was similar in men and women. There was no improvement on the inductive reasoning test. The results support the conclusion that the spatial visualization ability can be improved with training.  相似文献   

18.
Why is context important in human resource management (HRM) research? What and how contextual factors may be studied when investigating an organisational phenomenon? Against a positivist trend of decontextualisation in HRM research, this paper addresses these questions by situating them in an international context. It argues that context is important in making sense of what is happening at workplaces in order to provide relevant solutions. It also outlines three layers of context and draws on an empirical story to illustrate how the utilisation and conceptualisation of context may be underpinned by the researcher's intellectual and social upbringing and theoretical orientation. The paper calls for more qualitative studies to redress the imbalance in HRM research. It also calls for a more open‐minded, inductive, and inclusive approach to indigenous research that may present very different contexts, ways of contextualising, and knowledge paradigms from the dominant discourses prevailing in HRM research.  相似文献   

19.
信贷配给:从理论模型到中国实际   总被引:4,自引:0,他引:4  
张勋民 《价值工程》2004,23(6):113-116
信贷配给是各国资金配置中常见的现象,在中国更是普遍存在“中小企业贷款难”的问题。这究竟是一种短期行为还是长期均衡现象,究竟是政府的干预造成还是商业银行自身理性行为使然?本文将利用信息经济学知识对信贷配给做出均衡分析,并进行模型的扩展,结合中国实际探讨如何减少因信息不对称带来的信贷配给。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号