经典错误逻辑的相似转化词

经典错误逻辑研究的是错误传递、转化的规律,它为决策中避免错误,消除错误,减小错误的危害提供了新的方法.相似转化词是经典错误逻辑中的一个重要转化词,定义了相似转化词的概念,研究了这个转化词所具有的性质和规律.     

模糊错误逻辑的组合转化词分析

模糊错误逻辑研究的是错误传递、转化的规律,它为决策中避免错误,消除错误,减小错误的危害提供了新的方法.组合转化词是模糊错误逻辑中的一个重要转化词,定义了组合转化词的概念.分析了这个转化词的性质和运算规律.     

模糊错误逻辑的增加转化词及其在规避金融衍生交易风险中的应用

研究模糊错误逻辑的增加转化词在错误的传递、转化与消除过程中的性质和规律,建立了避免金融衍生交易风险的数学模型,介绍了增加转化词在避免金融衍生交易风险中的应用方法。     

模糊错误逻辑分解转化词与内涵否定词的逻辑关系

在文 [1]的基础上 ,在简单分析现时中错误的传递与转化的实际存在的同时 ,介绍国内外在逻辑研究领域对事物传递与转化规律的研究现状。特别为了探索控制与防范证券风险的技术而主要研究模糊错误逻辑分解转化词与内涵否定词的逻辑关系。     

模糊错误逻辑事物毁灭转化联结词研究

给出模糊错误逻辑事物毁灭转化联结词所涉及的概念、运算及其模糊错误逻辑事物毁灭转化联结词与外延联结词否定,∧合取,∨析取,∨bxr不相容析取,→实质蕴涵等和对模糊错误逻辑事物毁灭转化联结词与内涵联结词∧n内涵合取词,∨n内涵析取,—n内涵差取,/nf l内涵分离,/nf h内涵分化,∥nhb内涵互补,∥-nhd l内涵对立等的关系作了一点研究。     

基于实物期权的土地转化开发决策研究

在几何布朗运动假设基础上利用实物期权方法分析了不确定环境下农业用地向城市用地转化问题,得到了地价结构函数,同时利用首次达到时间理论分析了这一问题的可达性,并进行了比较静态分析,最后通过在转化开发前后征收不同税率分析了税收对土地转化和地价的影响.研究加深了我们对土地转化开发中的各种经济现象的理解和认识,并为房地产开发中的科学决策提供了理论支持.     

基于成果转化贡献的科研团队成员收益分配研究

促进科技成果转化是我国深化科技体制改革的重要内容,是科技成果转化为现实生产力的关键环节,是实施创新驱动发展战略的根本要求。科研团队成员作为企业科技创新活动的主体,让其参与成果转化收益的分配,有利于调动其科技创新与成果转化的积极性。本文通过理论分析,采用主成分分析法和关键绩效指标法,研究科研团队成员在成果转化阶段的贡献的关键指标、权重及量表,构建收益分配模型。研究结论为完善科技成果转化各利益相关者的激励机制提供了理论依据。     

知识约简和属性约简的转化及等价性

研究了知识库的知识约简和知识表达系统的属性约简的转化和联系,证明了这两种约简在一定意义下可相互转化且是等价的。     

阅读与转化一例

数学中的转化与化归思想,是指在研究和解决有关数学问题时,采用某种手段将问题通过变换使之转化,进而得到解决的一种思想.常见的转化方式有：一般向特殊转化、复杂向简单转化、数形转化、构造转化、类比转化等.能否有意识地运用转化与化归思想解决问题,往往取决于能否发现待解问题中的转化点.     

失业型贫困群体的创业意向-行为转化研究——应用半参数Cox风险模型的触发效应分析

研究应用事件史分析方法跟踪失业型贫困群体创业意向到创业行为转化的过程,解释是什么因素影响着这一独特群体创业行为的触发.在研究中,构建了包含情景因素的"意向一行为"解释框架,估计"意向一行为"的转化时间,将转化的时间间隔作为创业状态转换事件的"生存时间",应用事件史分析中的半参数Cox风险模型,考察外驱力和内驱力因素对这种时间间隔的触发效用差异.研究结果表明,"意向一行为"的转化时间在地区和性别之间的差异显著,并受到体制工作经验背景、创业培训、创业行为态度的多重影响.基于以上研究结论,针对缩短创业意向转化时间、维持创业者创业热情、鼓励女性创业等提出政策建议.     

Subword complexes and edge subdivisions

For a finite Coxeter group, a subword complex is a simplicial complex associated with a pair (Q, π), where Q is a word in the alphabet of simple reflections and π is a group element. We discuss the transformations of such a complex that are induced by braid moves of the word Q. We show that under certain conditions, such a transformation is a composition of edge subdivisions and inverse edge subdivisions. In this case, we describe how the H- and γ-polynomials change under the transformation. This case includes all braid moves for groups with simply laced Coxeter diagrams.     

Extension of Karmarkar's algorithm onto convex quadratically constrained quadratic problems

Convex quadratically constrained quadratic problems are considered. It is shown that such problems can be transformed to aconic form. The feasible set of the conic form is the intersection of a direct product of standard quadratic cones intersected with a hyperplane (the analogue of a simplex), and a linear subspace. For a problem of such form, the analogue of Karmarkar's projective transformation and logarithmic barrier function are built. This allows us to extend “word by word” the method of Karmarkar for LP to QCQP and allows us to obtain a similar polynomial worst-case bound for the number of iterations.     

Coping strategies applied to comprehend multistep arithmetic word problems by students with above-average numeracy skills and below-average reading skills

This article discusses how 13-year-old students with above-average numeracy skills and below-average reading skills cope with comprehending word problems. Compared to other students who are proficient in numeracy and are skilled readers, these students are more disadvantaged when solving single-step and multistep arithmetic word problems. The difference is smaller for single-step word problems. Analysis of large-scale data as well as a case study suggested that students used knowledge of stereotype item formats and keywords to cope with comprehending word problems. Instances where students used prior experiences to form predispositions to word problems were observed in the case study. In addition, analyses in both studies revealed that errors caused by overuse of keywords were more frequent among the students with below-average reading skills.     

Complexity results on restricted instances of a paint shop problem for words

We study the following problem: an instance is a word with every letter occurring twice. A solution is a 2-coloring of its letters such that the two occurrences of every letter are colored with different colors. The goal is to minimize the number of color changes between adjacent letters.This is a special case of the paint shop problem for words, which was previously shown to be NP-complete. We show that this special case is also NP-complete and even APX-hard. Furthermore, derive lower bounds for this problem and discuss a transformation into matroid theory enabling us to solve some specific instances within polynomial time.     

Multi-objective optimization of mobile phone keymaps for typing messages using a word list

Most mobile phones today offer the option of using a word list to ease the typing of short messages (SMS). When a word list is used, a word is input as a sequence of digits by pressing the key corresponding to each letter once. The word list is used to look up the word(s) that correspond to this sequence of digits. This paper describes how a mobile phone keyboard layout can be obtained that is better suited for typing such messages. Two objectives are considered: the total cost of typing, and the total cost of word clashes that occur when a certain digit sequence corresponds to two or more words in the word list. A multi-start descent algorithm is developed to obtain a Pareto set of solutions.     

Context representation using word sequences extracted from a news corpus

The ambiguity in language is one of the most difficult problems in dealing with word senses using computers. Word senses vary dynamically depending on context. We need to specify the context to identify these. However, context also varies depending on specificity and the viewpoint of the topic. Therefore, generally speaking, people pay attention to the part of the attributes of the entity, which the dictionary definition of the word indicates, depending on such variant contexts. Dealing with word senses on computer can be split into two steps. The first is to determine all the different senses for every word, and the second is to assign each occurrence of a word to the appropriate sense. In this paper, we propose a method focusing on the first step, which is to generate atomic conceptual fuzzy sets using word sequences. Then, both contexts identified by word sequences and atomic conceptual fuzzy sets, which express word senses, and that are related to the contexts can be shown concretely. We used the Reuters collection consisting of 800,000 news articles, and extracted word sequences and generated fuzzy sets automatically using the confabulation model (a prediction method similar to the n-gram model) and five statistical measures as relations. We compared the compatibility between the confabulation model and each measure, and found that cogency and mutual information were the most effective in representing context. We demonstrate the usefulness of the word sequences to identify the context.     

Free products and the word problem

An example is given to show that even in a variety whose free word problem (identity problem) is solvable, the free product of two recursive presentations with solvable word problems may have unsolvable word problem. Under some extra conditions on the syntax of the identities defining the variety however, the free product is shown to preserve solvability of the word problem for recursive presentations. The conditions can be checked mechanically, and common varieties such as semigroups and groups satisfy them, as well as many less familiar varieties. The results are obtained by using rewrite-completion techniques.Presented by Ralph Freese.     

Word problems in mathematics education: a survey

Word problems are among the most difficult kinds of problems that mathematics learners encounter. Perhaps as a result, they have been the object of a tremendous amount research over the past 50 years. This opening article gives an overview of the research literature on word problem solving, by pointing to a number of major topics, questions, and debates that have dominated the field. After a short introduction, we begin with research that has conceived word problems primarily as problems of comprehension, and we describe the various ways in which this complex comprehension process has been conceived theoretically as well as the empirical evidence supporting different theoretical models. Next we review research that has focused on strategies for actually solving the word problem. Strengths and weaknesses of informal and formal solution strategies—at various levels of learners’ mathematical development (i.e., arithmetic, algebra)—are discussed. Fourth, we address research that thinks of word problems as exercises in complex problem solving, requiring the use of cognitive strategies (heuristics) as well as metacognitive (or self-regulatory) strategies. The fifth section concerns the role of graphical representations in word problem solving. The complex and sometimes surprising results of research on representations—both self-made and externally provided ones—are summarized and discussed. As in many other domains of mathematics learning, word problem solving performance has been shown to be significantly associated with a number of general cognitive resources such as working memory capacity and inhibitory skills. Research focusing on the role of these general cognitive resources is reviewed afterwards. The seventh section discusses research that analyzes the complex relationship between (traditional) word problems and (genuine) mathematical modeling tasks. Generally, this research points to the gap between the artificial word problems learners encounter in their mathematics lessons, on the one hand, and the authentic mathematical modeling situations with which they are confronted in real life, on the other hand. Finally, we review research on the impact of three important elements of the teaching/learning environment on the development of learners’ word problem solving competence: textbooks, software, and teachers. It is shown how each of these three environmental elements may support or hinder the development of learners’ word problem solving competence. With this general overview of international research on the various perspectives on this complex and fascinating kind of mathematical problem, we set the scene for the empirical contributions on word problems that appear in this special issue.

     

The sequence of open and closed prefixes of a Sturmian word

A finite word is closed if it contains a factor that occurs both as a prefix and as a suffix but does not have internal occurrences, otherwise it is open. We are interested in the oc-sequence of a word, which is the binary sequence whose n-th element is 0 if the prefix of length n of the word is open, or 1 if it is closed. We exhibit results showing that this sequence is deeply related to the combinatorial and periodic structure of a word. In the case of Sturmian words, we show that these are uniquely determined (up to renaming letters) by their oc-sequence. Moreover, we prove that the class of finite Sturmian words is a maximal element with this property in the class of binary factorial languages. We then discuss several aspects of Sturmian words that can be expressed through this sequence. Finally, we provide a linear-time algorithm that computes the oc-sequence of a finite word, and a linear-time algorithm that reconstructs a finite Sturmian word from its oc-sequence.     

Interactions Between Natural Language and Mathematical Structures: The Case of "Wordwalking"

In the course of solving relatively routine word problems, 7th-grade students sometimes made a substitution of a word or phrase in the original problem statement. The substitutions discussed here appeared insignificant because the natural language meaning overlapped with that of the replaced word or phrase, but they had major consequences mathematically because they affected the mathematical structure that modeled the resulting problem statement. The term wordwalking was coined to refer to such substitutions. Wordwalking was observed during qualitative data reduction required for the coding of a quantitative study. The relative ambiguity of natural language and the precision of mathematical expressions are invoked to explain the dynamics of wordwalking.