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1.
Learners may increasingly encounter conflicting expert reports. However, little is known about how they deal with this challenge. We examined how learners' familiarity with a controversial historical topic affects their epistemic judgments of conflicting expert claims and sources, the interplay of their claim and source evaluation strategies, and their meta-epistemic understanding of the legitimacy of the disagreement (absolutist, multiplist, and evaluativist perspectives). In two studies, topic familiarity increased agreement with belief-consistent expert claims and the perceived trustworthiness of the expert who presented these claims. Topic familiarity also impacted the coordination of evaluation strategies and led to greater reliance on knowledge-based validation. However, topic familiarity did not affect meta-epistemic understanding of the legitimacy of the controversy. In the second study, reading an explanation about reasons for disagreements between historians resulted in higher evaluativism. Teaching about expert disagreement may be a productive approach for promoting appreciation of the diversity of knowledge.  相似文献   
2.
Aspect mining, which aims to extract ad hoc aspects from online reviews and predict rating or opinion on each aspect, can satisfy the personalized needs for evaluation of specific aspect on product quality. Recently, with the increase of related research, how to effectively integrate rating and review information has become the key issue for addressing this problem. Considering that matrix factorization is an effective tool for rating prediction and topic modeling is widely used for review processing, it is a natural idea to combine matrix factorization and topic modeling for aspect mining (or called aspect rating prediction). However, this idea faces several challenges on how to address suitable sharing factors, scale mismatch, and dependency relation of rating and review information. In this paper, we propose a novel model to effectively integrate Matrix factorization and Topic modeling for Aspect rating prediction (MaToAsp). To overcome the above challenges and ensure the performance, MaToAsp employs items as the sharing factors to combine matrix factorization and topic modeling, and introduces an interpretive preference probability to eliminate scale mismatch. In the hybrid model, we establish a dependency relation from ratings to sentiment terms in phrases. The experiments on two real datasets including Chinese Dianping and English Tripadvisor prove that MaToAsp not only obtains reasonable aspect identification but also achieves the best aspect rating prediction performance, compared to recent representative baselines.  相似文献   
3.
Contextual document clustering is a novel approach which uses information theoretic measures to cluster semantically related documents bound together by an implicit set of concepts or themes of narrow specificity. It facilitates cluster-based retrieval by assessing the similarity between a query and the cluster themes’ probability distribution. In this paper, we assess a relevance feedback mechanism, based on query refinement, that modifies the query’s probability distribution using a small number of documents that have been judged relevant to the query. We demonstrate that by providing only one relevance judgment, a performance improvement of 33% was obtained.  相似文献   
4.
In this paper, we propose a new language model, namely, a dependency structure language model, for topic detection and tracking (TDT) to compensate for weakness of unigram and bigram language models. The dependency structure language model is based on the Chow expansion theory and the dependency parse tree generated by a linguistic parser. So, long-distance dependencies can be naturally captured by the dependency structure language model. We carried out extensive experiments to verify the proposed model on topic tracking and link detection in TDT. In both cases, the dependency structure language models perform better than strong baseline approaches.  相似文献   
5.
In this paper, we present a topic discovery system aimed to reveal the implicit knowledge present in news streams. This knowledge is expressed as a hierarchy of topic/subtopics, where each topic contains the set of documents that are related to it and a summary extracted from these documents. Summaries so built are useful to browse and select topics of interest from the generated hierarchies. Our proposal consists of a new incremental hierarchical clustering algorithm, which combines both partitional and agglomerative approaches, taking the main benefits from them. Finally, a new summarization method based on Testor Theory has been proposed to build the topic summaries. Experimental results in the TDT2 collection demonstrate its usefulness and effectiveness not only as a topic detection system, but also as a classification and summarization tool.  相似文献   
6.
当前我国各省区就业人员的聚类分析   总被引:1,自引:0,他引:1  
进行全国各省区吸纳就业人员的聚类分析,要选择影响就业水平的指标,计算出相关数据并进行标准化处理,以利用SPSS聚类分析得出结论.  相似文献   
7.
以金边瑞香茎尖为外植体,探讨了不同培养基对丛生芽的诱导增殖、芽苗生根的影响。结果表明:1)金边瑞香丛生芽的诱导增殖可用培养基B5大量无机成分 MS微量无机成分 B5维生素 BA2.0 mg.L-1;2)丛生芽形成一定高度的芽苗后,接入培养基1/2B5 NAA50 mg.L-1中培养10 d,然后接入1/2B5培养基中可获得最佳生根效果.  相似文献   
8.
舞蹈是以经过提炼、组织和艺术加工的人体动作为主要表现手段,表达人们的思想感情,反映社会生活的一种艺术形式。舞蹈的编导创作是实践性的活动过程。本文结合实践从舞蹈动作、舞蹈创作构思和舞蹈构图三个方面阐述和分析了如何进行舞蹈的创编。  相似文献   
9.
为挖掘当前社交网络中具有相同内在因素、特定组织结构的群体,提出一种基于特定用户的群体关系挖掘与分析方法。首先,以特定用户为切入点,改进基于最短路径的图聚类算法,以此关联它们之间的关系,构建初级群体;然后,构造初级群体属性特征比对集合,利用动态权重相似性对其进行扩展,挖掘它们所处的群体;最后,对挖掘出的群体进行聚类效果评估。实验结果表明,该方法聚类效果良好,能够有效挖掘相关群体,为社交网络中的群体发现提供了新思路。  相似文献   
10.
遗传算法作为一种通用的寻优方法 ,本文将其用于PD (pulseDoppler)雷达的解模糊处理 .基于多重PRF (pulserepeatfrequency ,脉冲重复频率 )之间所有可能距离的均方误差 ,设计了适应度函数 ;讨论了基于逼近交叉策略的遗传算法在PD雷达解模糊中的应用 ,并通过仿真分析了解模糊正确率、测量误差、计算效率等之间的关系 .仿真结果证明该方法的解模糊正确率与滑窗相关器算法比较有了较大的提高 .  相似文献   
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