一种双向聚类协同过滤推荐算法研究     

范奥哲  何利力 《教育技术导刊》2020,19(5):78-82

针对传统协同过滤推荐算法在大数据环境下存在数据稀疏性及计算复杂性等问题,提出一种双向聚类协同过滤推荐算法。该算法首先从用户维度和项目维度两个方向分别进行属性聚类,然后在目标用户和目标项目所在类簇中分别使用改进后的相似度计算方法进行协同过滤推荐,最后通过平衡因子综合预测评分并形成最终推荐列表。在 MovieLens 公开数据集上进行实验,结果表明,该算法（DCF）相比传统协同过滤推荐算法（TCF）、基于用户聚类的协同过滤推荐算法（UCF）以及基于项目聚类的协同过滤推荐算法（ICF）,在平均绝对误差上分别降低了 16%、8.1%、7.5%,有效提高了推荐精度。  相似文献   

大数据时代高校图书馆参考咨询服务的创新与发展     

赵雪琛 《教育教学论坛》2020,(10):68-69

高校图书馆参考咨询服务工作不仅是体现其人性化、现代化、信息化服务的重要表现,也是满足广大师生群体提高自身查阅资料效率和质量的重要保障。为充分发挥大数据时代对高校图书馆参考咨询服务管理的优势,从而促进高校图书馆参考咨询服务的创新与发展,作者以《大数据时代高校图书馆参考咨询服务的创新与发展》为课题,从引言入手,对大数据时代高校图书馆参考咨询服务现状进行了全方位、深层次的剖析,并在此基础上深入地探究了大数据时代高校图书馆参考咨询服务创新与发展策略,给出了作者具有代表性的个人建议。  相似文献   

Shifting the focus of validity for test use     

Pamela A. Moss 《Assessment in Education: Principles, Policy & Practice》2016,23(2):236-251

The conventional focus of validity in educational measurement has been on intended interpretations and uses of test scores. Empirical studies of test use by teachers, administrators and policy-makers show that actual interpretations and uses of test scores in context are invariably shaped by local users’ questions, which frequently require attention to multiple sources of evidence about students’ learning and the factors that shape it, and depend on local capacity to use such information well. This requires a more complex theory of validity that can shift focus as needed from the intended interpretations and uses of test scores that guide test developers to local capacity to support the actual interpretations, decisions and actions that routinely serve local users’ purposes. I draw on the growing empirical literature on data use to illustrate the need for an expanded theory of validity, point to theoretical resources that might guide such an expansion, and suggest a research agenda towards these ends.  相似文献   

基于数据挖掘技术的CRM系统研究     

江学锋  罗新星 《深圳职业技术学院学报》2005,4(4):36-38

数据挖掘是CRM的核心，作者介绍了数据挖掘的概念、过程、目标，并分析了基于数据挖掘的CRM的特征。在此基础上提出了基于数据挖掘的面向CRM的综合决策支持系统模型。  相似文献   

机器数在数轴上的表示方法     

王国伟 《河西学院学报》2002,18(2):22-24

介绍了机器数在数轴上的几何表示方法，并用此方法分析了补码运算的溢出问题．  相似文献   

The Relative Efficiency of Departments at a Turkish Engineering College: A Data Envelopment Analysis     

Gülser Köksal  Burak Nalçaci 《Higher Education》2006,51(2):173-189

In this study, Data Envelopment Analysis is used to measure relative efficiencies of academic departments of an engineering college. Input and output criteria are determined and measured utilizing the academic personnel performance measurement scheme of the College. New measures are developed to compare departments of different disciplines. The discriminating power of the measurement models is improved by restricting criteria weights directly and by using a multiple criteria decision making approach. Sensitivity of the results to exclusion of a criterion and changes in relative importance of the criteria is analyzed. Evaluation of the results jointly by the college administration and the departments is explained for a successful efficiency improvement mechanism.  相似文献   

Bayesian Regularized Multivariate Generalized Latent Variable Models     

Xiang-Nan Feng  Xin-Yuan Song 《Structural equation modeling》2017,24(3):341-358

We consider a multivariate generalized latent variable model to investigate the effects of observable and latent explanatory variables on multiple responses of interest. Various types of correlated responses, such as continuous, count, ordinal, and nominal variables, are considered in the regression. A generalized confirmatory factor analysis model that is capable of managing mixed-type data is proposed to characterize latent variables via correlated observed indicators. In addressing the complicated structure of the proposed model, we introduce continuous underlying measurements to provide a unified model framework for mixed-type data. We develop a multivariate version of the Bayesian adaptive least absolute shrinkage and selection operator procedure, which is implemented with a Markov chain Monte Carlo (MCMC) algorithm in a full Bayesian context, to simultaneously conduct estimation and model selection. The empirical performance of the proposed methodology is demonstrated through a simulation study. An application of the proposed method to a study of adolescent substance abuse based on the National Longitudinal Survey of Youth is presented.  相似文献   

Visualising Correlation with Spreadsheets     

Erich Neuwirth 《Teaching Statistics》1990,12(3):86-88

When teaching correlation it is often very useful to show examples of data sets with a given correlation. This article describes a method using a spreadsheet to generate such scatterplots and to obtain “confidence regions”.  相似文献   

My tongue on your theory: the bittersweet reminder of every-thing unnameable     

Rachel Holmes 《Discourse: Studies in the Cultural Politics of Education》2016,37(5):662-679

ABSTRACT

Across research in UK Higher Education, the most immanent demands for quality have taken the shape of the Research Assessment Exercise and the Research Excellence Framework (REF). The theorist, Martin, is cautious of the relationship academics have engendered with the process of the REF, asking are we actually creating a Frankenstein monster, becoming complicit in generating quality thresholds and standards that will become our own tormentors? I am taken by the idea of the monster when pursuing alternative discourses of childhood in educational research – fear of its potential to torment seduces me with the promise of dis-order, de-formity, chaos and mutation. The aim of this paper is to resist a fixed, knowable form of ‘quality’ (in) research, moving between the idea of ‘monster’ and the formlessness of ‘monstrosity’ to oppose the epistemological, ontological and ethical paradigms of reason.  相似文献   

沿海地区设计潮位计算方法探讨   总被引：1，自引：0，他引：1  

孔乐  陈娥 《泰州职业技术学院学报》2005,5(3):36-38

采用P-Ⅲ型分布及极值Ⅰ型分布,研究了沿海地区设计潮位计算方法.阐述了资料的一致性检验的方法.结合坎门站潮位资料,对比了两种方法的计算效果.结果表明,两种方法对不同重现期设计值的估计结果相当,但P-Ⅲ型分布计算时参数的选取与习惯用法不符,因此,建议采用极值Ⅰ型分布进行设计潮位计算.  相似文献