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数字图书馆系统中基于Ontology的用户偏好模型 总被引:2,自引:0,他引:2
个性化服务技术为数字图书馆的研究带来一些新的挑战.如何描述用户的偏好以及如何使数字图书馆支持偏好查询是有待研究的一个问题.人们已经提出了基于偏序关系的用户偏好模型,并针对关系数据提出了一系列偏好构造方法.数字图书馆中的数据是半结构数据.半结构数据上用户偏好的描述比关系数据复杂得多.偏序模型无法有效地表达数字图书馆中的用户偏好.提出基于ontology的新的用户偏好模型,用ontology来描述数字图书馆中的文本和文本上的偏好.该模型能够充分表达用户偏好的结构和语义,并提供了复杂的偏好操作,能够有效地支持数字图书馆中的个性化检索和推荐操作. 相似文献
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针对专家之间具有优先关系时直觉乘法偏好关系下群体共识决策问题,提出一种基于优先集成算子的直觉乘法偏好关系共识方法。为了有效集结专家偏好信息,提出直觉乘法优先加权平均(IMPWA)算子和直觉乘法优先加权几何(IMPWG)算子,并研究其相关性质;定义直觉乘法偏好关系的共识度和接近度概念,据此完成非共识偏好信息的识别和修正,构建一种迭代共识算法。案例表明该方法的可行性和有效性。 相似文献
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丁宪成 《计算机工程与应用》2016,52(24):62-69
模糊偏好关系是处理决策问题的一种有效工具。针对模糊偏好关系,研究了加性一致性模糊偏好关系的若干判定条件,构造了满足加性一致性的特征模糊偏好关系,并提出一致性指数、满意加性一致性等概念。在此基础上,构建了不满足加性一致性模糊偏好关系的改进算法,论证了算法的收敛性,该算法使得改进后的模糊偏好关系具有满意一致性条件,进而使得决策者获得合理可靠的决策结果。最后建立了基于模糊偏好关系加性一致性的决策模型。实例分析说明提出的模糊偏好关系决策模型是可行和有效的。 相似文献
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传统关于偏好推理、偏好查询的研究主要集中在对关系元组表示的单个对象的偏好上,而将时间条件偏好查询的方法扩展到数据流的提取序列中是一个挑战,遇到的问题主要包括对数据流中序列的提取、快速处理以得到占优序列和占优对象等.针对偏好数据流,首先,扩展了连续查询语言(CQL),提出专门为有效处理数据流上的时间条件偏好的查询语言St... 相似文献
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针对犹豫模糊元中元素发生的概率信息不完备的群决策问题,提出一种基于最优化模型和一致性调整算法的群决策模型。该模型首先引入了概率不完备犹豫模糊偏好关系(PIHFPR)、概率不完备犹豫模糊偏好关系的期望一致性以及概率不完备犹豫模糊偏好关系的满意加性期望一致性等概念;其次,以PIHFPR和排序权重向量间的偏差最小化作为目标函数,构建线性最优化模型计算得到PIHFPR中不完备的概率信息;随后,通过提出的加权概率不完备犹豫模糊偏好关系集成算子确定综合的PIHFPR,同时设计一种群体一致性调整算法,不仅使得调整后的PIHFPR具有满意加性期望一致性,还可以计算方案的排序权重。最后,将群决策模型应用于区块链的选择实例中。实验结果表明,决策结果合理可靠,且更能反映实际决策情况。 相似文献
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针对移动网络对个性化移动网络服务系统的性能提出了更高的要求,但现有研究难以自适应地修改上下文移动用户偏好以为移动用户提供实时、准确的个性化移动网络服务的问题,提出了一种上下文移动用户偏好自适应学习方法,在保证精确度的基础上缩短了学习的响应时间.首先,通过分析移动用户行为日志来判断移动用户行为是否受上下文影响,并在此基础上判断移动用户行为是否发生变化.然后,根据判断结果对上下文移动用户偏好进行修正.在对发生变化的上下文移动用户偏好进行学习时,将上下文引入到最小二乘支持向量机中,进一步提出了基于上下文最小二乘支持向量机(C-LSSVM)的上下文移动用户偏好学习方法.最后,实验结果表明,当综合考虑精确度和响应时间两方面因素时,所提出的方法优于其他学习方法,并且可应用于个性化移动网络服务系统中. 相似文献
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The binary relation framework has been shown to be applicable to many real-life preference handling scenarios. Here we study preference contraction: the problem of discarding selected preferences. We argue that the property of minimality and the preservation of strict partial orders are crucial for contractions. Contractions can be further constrained by specifying which preferences should be protected. We consider preference relations that are finite or finitely representable using preference formulas. We present algorithms for computing minimal and preference-protecting minimal contractions for finite as well as finitely representable preference relations. We study relationships between preference change in the binary relation framework and belief change in the belief revision theory. We evaluate the proposed algorithms experimentally and present the results. 相似文献
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The aim of this paper is to investigate decision making problems with interval-valued intuitionistic fuzzy preference information, in which the preferences provided by the decision maker over alternatives are incomplete or uncertain. We define some new preference relations, including additive consistent incomplete interval-valued intuitionistic fuzzy preference relation, multiplicative consistent incomplete interval-valued intuitionistic fuzzy preference relation and acceptable incomplete interval-valued intuitionistic fuzzy preference relation. Based on the arithmetic average and the geometric mean, respectively, we give two procedures for extending the acceptable incomplete interval-valued intuitionistic fuzzy preference relations to the complete interval-valued intuitionistic fuzzy preference relations. Then, by using the interval-valued intuitionistic fuzzy averaging operator or the interval-valued intuitionistic fuzzy geometric operator, an approach is given to decision making based on the incomplete interval-valued intuitionistic fuzzy preference relation, and the developed approach is applied to a practical problem. It is worth pointing out that if the interval-valued intuitionistic fuzzy preference relation is reduced to the real-valued intuitionistic fuzzy preference relation, then all the above results are also reduced to the counterparts, which can be applied to solve the decision making problems with incomplete intuitionistic fuzzy preference information. 相似文献
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Advanced personalized e-applications require comprehensive knowledge about their users’ likes and dislikes in order to provide individual product recommendations, personal customer advice, and custom-tailored product offers. In our approach we model such preferences as strict partial orders with “A is better than B” semantics, which has been proven to be very suitable in various e-applications. In this paper we present preference mining techniques for detecting strict partial order preferences in user log data. Real-life e-applications like online shops or financial services usually have large log data sets containing the transactions of their customers. Since the preference miner uses sophisticated SQL operations to execute all data intensive operations on database layer, our algorithms scale well even for such large log data sets. With preference mining personalized e-applications can gain valuable knowledge about their customers’ preferences, which can be applied for personalized product recommendations, individual customer service, or one-to-one marketing. 相似文献
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Group consensus algorithms based on preference relations 总被引:1,自引:0,他引:1
In many group decision-making situations, decision makers’ preferences for alternatives are expressed in preference relations (including fuzzy preference relations and multiplicative preference relations). An important step in the process of aggregating preference relations, is to determine the importance weight of each preference relation. In this paper, we develop a number of goal programming models and quadratic programming models based on the idea of maximizing group consensus. Our models can be used to derive the importance weights of fuzzy preference relations and multiplicative preference relations. We further develop iterative algorithms for reaching acceptable levels of consensus in group decision making based on fuzzy preference relations or multiplicative preference relations. Finally, we include an illustrative example. 相似文献
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The experts may have difficulty in expressing all their preferences over alternatives or criteria, and produce the incomplete linguistic preference relation. Consistency plays an important role in estimating unknown values from an incomplete linguistic preference relation. Many methods have been developed to obtain a complete linguistic preference relation based on additive consistency, but some unreasonable values may be produced in the estimation process. To overcome this issue, we propose a new characterisation about multiplicative consistency of the linguistic preference relation, present an algorithm to estimate missing values from an incomplete linguistic preference relation, and establish a decision support system for aiding the experts to complete their linguistic preference relations in a more consistent way. Some examples are also given to illustrate the proposed methods. 相似文献
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In order to simulate the hesitancy and uncertainty associated with impression or vagueness, a decision maker may give her/his judgments by means of hesitant fuzzy preference relations in the process of decision making. The study of their consistency becomes a very important aspect to avoid a misleading solution. This paper defines the concept of additive consistent hesitant fuzzy preference relations. The characterizations of additive consistent hesitant fuzzy preference relations are studied in detail. Owing to the limitations of the experts’ professional knowledge and experience, the provided preferences in a hesitant fuzzy preference relation are usually incomplete. Consequently, this paper introduces the concepts of incomplete hesitant fuzzy preference relation, acceptable incomplete hesitant fuzzy preference relation, and additive consistent incomplete hesitant fuzzy preference relation. Then, two estimation procedures are developed to estimate the missing information in an expert's incomplete hesitant fuzzy preference relation. The first procedure is used to construct an additive consistent hesitant fuzzy preference relation from the lowest possible number, (n − 1), of pairwise comparisons. The second one is designed for the estimation of missing elements of the acceptable incomplete hesitant fuzzy preference relations with more known judgments. Moreover, an algorithm is given to solve the multi-criteria group decision making problem with incomplete hesitant fuzzy preference relations. Finally, a numerical example is provided to illustrate the solution processes of the developed algorithm and to verify its effectiveness and practicality. 相似文献
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Database querying under changing preferences 总被引:1,自引:0,他引:1
Jan Chomicki 《Annals of Mathematics and Artificial Intelligence》2007,50(1-2):79-109
We present here a formal foundation for an iterative and incremental approach to constructing and evaluating preference queries.
Our main focus is query modification: a query transformation approach which works by revising the preference relation in the query. We provide a detailed analysis
of the cases where the order-theoretic properties of the preference relation are preserved in the revision. We consider a
number of different revision operators: union, prioritized and Pareto composition. We also formulate algebraic laws that enable
incremental evaluation of preference queries. Finally, we consider two variations of the basic framework: finite restrictions
of preference relations and weak-order extensions of strict partial order preference relations.
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Due to the uncertainty of the decision environment and the lack of knowledge, decision-makers may use uncertain linguistic preference relations to express their preferences over alternatives and criteria. For group decision-making problems with preference relations, it is important to consider the individual consistency and the group consensus before aggregating the preference information. In this paper, consistency and consensus models for group decision-making with uncertain 2-tuple linguistic preference relations (U2TLPRs) are investigated. First of all, a formula which can construct a consistent U2TLPR from the original preference relation is presented. Based on the consistent preference relation, the individual consistency index for a U2TLPR is defined. An iterative algorithm is then developed to improve the individual consistency of a U2TLPR. To help decision-makers reach consensus in group decision-making under uncertain linguistic environment, the individual consensus and group consensus indices for group decision-making with U2TLPRs are defined. Based on the two indices, an algorithm for consensus reaching in group decision-making with U2TLPRs is also developed. Finally, two examples are provided to illustrate the effectiveness of the proposed algorithms. 相似文献
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Now the handling of user preference is becoming an increasingly important issue in database fields where they capture soft criteria for queries. A broader category of qualitative preferences with dependent relations among multiple attributes is widely existing, which is CP-nets. In this article, we focus on designing the operators of preference composition for CP-nets. Firstly, we extend Pareto composition to our model by including equivalence relation ≈, incomparability relation ∥ and conflicting relation ⊥, which can preserve a strict partial order and conditional associativity. On this basis, two questions are solved: (a) the generation of satisfiability sequences for CP-nets, (b) the top-k queries of relational database with CP-nets preference. For (a), a CP-net is induced into multiple tables, consequently the strong dominance tests between outcomes can be solved by using preference composition instead of using induced preference graph of CP-nets. For (b), we adopt the concept of Query Lattice to provide a natural semantics for the block sequence answering a preference query, where two algorithms (called QOCP and IQOCP) are introduced. These questions are solved efficiently and effectively at the perspective of combination of graph model and relational database. 相似文献
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Consistent models of transitivity for reciprocal preferences on a finite ordinal scale 总被引:1,自引:0,他引:1
In this paper we consider a decision maker who shows his/her preferences for different alternatives through a finite set of ordinal values. We analyze the problem of consistency taking into account some transitivity properties within this framework. These properties are based on the very general class of conjunctors on the set of ordinal values. Each reciprocal preference relation on a finite ordinal scale has both a crisp preference and a crisp indifference relation associated to it in a natural way. Taking this into account, we have started by analyzing the problem of propagating transitivity from the preference relation on a finite ordinal scale to the crisp preference and indifference relations. After that, we carried out the analysis in the opposite direction. We provide some necessary and sufficient conditions for that propagation, and therefore, we characterize the consistent class of conjunctors in each direction. 相似文献