Local and global approaches of affinity propagation clustering for large scale data   总被引：2，自引：0，他引：2  

Ding-yin Xia  Fei Wu  Xu-qing Zhang  Yue-ting Zhuang 《浙江大学学报(A卷英文版)》2008,9(10):1373-1381

Recently a new clustering algorithm called ＇affinity propagation＇ （AP） has been proposed, which efficiently clustered sparsely related data by passing messages between data points. However, we want to cluster large scale data where the similarities are not sparse in many cases. This paper presents two variants of AP for grouping large scale data with a dense similarity matrix. The local approach is partition affinity propagation （PAP） and the global method is landmark affinity propagation （LAP）. PAP passes messages in the subsets of data first and then merges them as the number of initial step of iterations; it can effectively reduce the number of iterations of clustering. LAP passes messages between the landmark data points first and then clusters non-landmark data points; it is a large global approximation method to speed up clustering. Experiments are conducted on many datasets, such as random data points, manifold subspaces, images of faces and Chinese calligraphy, and the results demonstrate that the two approaches are feasible and practicable.  相似文献   

确保供应链安全背景下,广东企业研究院的创建思路     

王卫红  张威 《科技管理研究》2020,40(24):138-143

受中美博弈、疫情冲击叠加影响可能出现的“逆全球化”甚至“去中国化”的环境背景下，为确保供应链安全，在广东大型企业创建研究院具有重要的战略意义和现实意义。研究广东大型制造业企业研究院的功能定位和主要作用，探讨创建企业研究院的思路及运行机制，为广东大型企业创建研究院提供对策建议。研究认为：应创建一批国家级和省级研究院；梳理重点产业的短板技术、关键技术瓶颈清单，支持企业研究院重点攻关；构建多元化、多层次投资机制，对承担清单上核心技术攻关的研究院重点支持；围绕确保供应链安全、做强产业链、部署创新链的目标，进行规划和政策制定；为大型企业研究院建设吸引、凝聚高端人才。  相似文献   

大系统思维—21世纪管理的主要思维方法     

代杰  赖晓鹏 《临沂师范学院学报》2001,23(2):8-10

大系统思维是随着时代发展而出现的一种新的思维方法，它的特征和原则决定它必然成为21世纪管理的主要思维方法。  相似文献   

狂欢的符号--大型电视平民选秀节目的文化阐释   总被引：1，自引：0，他引：1  

田中阳  赵颖峰 《湖南大众传媒职业技术学院学报》2006,6(3):19-21

自2004年以来,大型电视平民选秀节目愈演愈盛,对其评价也褒贬不一。本文从符号学理论与狂欢节理论角度切入,以《超级女声》为文本,对这类型节目进行文化解释。该类节目在满足广大受众对颠覆层级及建构乌托邦式理想生活的欲望的同时成为缓解社会焦虑的“溢洪道”,从而起到维持现有社会秩序正常持续运转的重要作用。  相似文献   

大整数运算的抽象类研究与设计     

王溢琴  齐悦 《人天科学研究》2010,(1)

大整数运算应用广泛,但常常受限于计算机硬件与软件的能力。研究并设计了一个用于大整数运算的C++抽象类作为大整数运算的统一接口,采用链表实现动态分配存储空间,从而可以实现各种类型、无限大的整数科学计算。  相似文献   

What changes,and for whom? A study of the impact of learning analytics-based process feedback in a large course     

《Learning and Instruction》2021

Recent developments in educational technologies have provided a viable solution to the challenges associated with scaling personalised feedback to students. However, there is currently little empirical evidence about the impact such scaled feedback has on student learning progress and study behaviour. This paper presents the findings of a study that looked at the impact of a learning analytics (LA)-based feedback system on students' self-regulated learning and academic achievement in a large, first-year undergraduate course. Using the COPES model of self-regulated learning (SRL), we analysed the learning operations of students, by way of log data from the learning management system and e-book, as well as the products of SRL, namely, performance on course assessments, from three years of course offerings. The latest course offering involved an intervention condition that made use of an educational technology to provide LA-based process feedback. Propensity score matching was employed to match a control group to the student cohort enrolled in the latest course offering, creating two equal-sized groups of students who received the feedback (the experimental group) and those who did not (the control group). Growth mixture modelling and mixed between-within ANOVA were also employed to identify differences in the patterns of online self-regulated learning operations over the course of the semester. The results showed that the experimental group showed significantly different patterns in their learning operations and performed better in terms of final grades. Moreover, there was no difference in the effect of feedback on final grades among students with different prior academic achievement scores, indicating that the LA-based feedback deployed in this course is able to support students’ learning, regardless of prior academic standing.  相似文献   

Similarity caching in large-scale image retrieval     

Fabrizio Falchi  Claudio Lucchese  Salvatore Orlando  Raffaele Perego  Fausto Rabitti 《Information processing & management》2012

Feature-rich data, such as audio-video recordings, digital images, and results of scientific experiments, nowadays constitute the largest fraction of the massive data sets produced daily in the e-society. Content-based similarity search systems working on such data collections are rapidly growing in importance. Unfortunately, similarity search is in general very expensive and hardly scalable.  相似文献   

云南省三大体育场馆经营管理模式比较研究     

史永 《鞍山师范学院学报》2013,(6):81-84

主要采用文献资料法、专家访谈法、逻辑分析与比较研究相结合的方法,经实地考查后,运用管理学、经济学等相关学科知识对目前云南省内的体育场馆经营管理模式及其经营管理现状进行研究。在对云南省3个大中型体育场馆中的产权、经营权和经营管理的投入产出进行比较分析后,发现其经营管理中的不足,为云南省内的大中型体育场馆的发展提供理论依据及借鉴意义。  相似文献   

Study of large medical equipment allocation in Xuzhou     

Miao CX  Zhuo L  Gu YM  Qin ZH 《Journal of Zhejiang University. Science. B》2007,8(12):881-884

Objective： To investigate the allocation and management of large medical equipment （LME） in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods： The research collected data from all hospitals that have LME in Xuzhou using questionnaire; 38 （97.4%） hospitals returned the questionnaire. Results： In Xuzhou, there are a total of 71 pieces of LME, each serving 126 600 people in an area of 163 km^2. Sixty-two percent of them are allocated in urban areas, with Gini coefficient at 0.52, indicating imbalance and biased allocation of LME. Conclusion： The allocation of LME in Xuzhou is out of control and unfairly allocated.  相似文献   

大起伏地区快速高程控制测量研究     

刘明学 《大众科技》2015,(5)

针对水准仪测量法在大起伏地区高程控制测量中作业速度慢、误差累积大的问题,采用全站仪中间设站法在大起伏地区进行高程控制测量。通过高程面归化改正和投影改正对测量距离进行处理,对全站仪中间设站法的测量影响因素进行分析,采用附合、闭合高程测量路线精度要求进行把控,通过测量实例验证全站仪中间设站法在大起伏地区快速高程控制测量中是实用性。  相似文献