全文获取类型
收费全文 | 930篇 |
免费 | 19篇 |
国内免费 | 38篇 |
专业分类
教育 | 604篇 |
科学研究 | 181篇 |
体育 | 5篇 |
综合类 | 78篇 |
信息传播 | 119篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 17篇 |
2020年 | 28篇 |
2019年 | 18篇 |
2018年 | 15篇 |
2017年 | 14篇 |
2016年 | 13篇 |
2015年 | 29篇 |
2014年 | 77篇 |
2013年 | 59篇 |
2012年 | 62篇 |
2011年 | 82篇 |
2010年 | 55篇 |
2009年 | 65篇 |
2008年 | 79篇 |
2007年 | 66篇 |
2006年 | 61篇 |
2005年 | 40篇 |
2004年 | 44篇 |
2003年 | 40篇 |
2002年 | 37篇 |
2001年 | 28篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有987条查询结果,搜索用时 15 毫秒
81.
程淑玉 《宜宾师范高等专科学校学报》2013,(6):82-85
个性化推荐系统被越来越多地应用到各类网站中,以解决信息增长带来的信息迷失和信息过栽问题,而协同过滤算法是个性化推荐系统的重要算法之一,但是传统的协同过滤算法存在数据稀疏、冷启动等问题,为了解决这些问题,在综合WEB日志挖掘和聚类两个因素基础上,提出基于WEB日志和聚类的协同过滤算法,并将该算法与传统的协同过滤算法进行分析比较,验证了该算法能够提高推荐的精确度和实时性. 相似文献
82.
常规PID算法,在被控对象具有不确定、非线性、变参数等因素的复杂环境中,难以满足控制要求,因此采用粒子群算法PSO(particle swarm optimization)对PID算法的Kp,Ki,Kd 3个参数进行在线整定.利用MATLAB软件对常规PID控制及粒子群PID控制进行仿真实验,仿真结果显示,相较于常规PID算法,PSO-PID控制算法具有更好的快速性和稳定性. 相似文献
83.
Lesly Alejandra Gonzalez Camacho Solange Nice Alves-Souza 《Information processing & management》2018,54(4):529-544
Recommender Systems are currently highly relevant for helping users deal with the information overload they suffer from the large volume of data on the web, and automatically suggest the most appropriate items that meet users needs. However, in cases in which a user is new to Recommender System, the system cannot recommend items that are relevant to her/him because of lack of previous information about the user and/or the user-item rating history that helps to determine the users preferences. This problem is known as cold-start, which remains open because it does not have a final solution. Social networks have been employed as a good source of information to determine users preferences to mitigate the cold-start problem. This paper presents the results of a Systematic Literature Review on Collaborative Filtering-based Recommender System that uses social network data to mitigate the cold-start problem. This Systematic Literature Review compiled the papers published between 2011–2017, to select the most recent studies in the area. Each selected paper was evaluated and classified according to the depth which social networks used to mitigate the cold-start problem. The final results show that there are several publications that use the information of the social networks within the Recommender System; however, few research papers currently use this data to mitigate the cold-start problem. 相似文献
84.
张虎 《苏州市职业大学学报》2021,(1)
针对早高峰短时交通流量预测数据少、波动大的特点,提出用灰色模型进行预测。将灰色GM(2,1)改进为灰色GM(2,1,λ,ρ)预测模型,以提高预测精度。针对粒子群算法(PSO)的早熟现象,将Logistic混沌搜索嵌入到PSO算法,应用混沌粒子群算法(CPSO)寻找灰色GM(2,1,λ,ρ)预测模型最优的参数λ和ρ。结合两者提出了基于CPSO–GM(2,1,λ,ρ)的早高峰短时交通流预测模型。利用VISSIM对研究路网进行微观交通仿真,通过VISSIM–Excel、VBA–Matlab平台实现了短时交通流量预测和路网微观交通仿真数据的交互,对集成交通控制系统的架构进行了方案设计。仿真结果表明,结合流量预测的路网优于固定信号配时下的路网仿真。 相似文献
85.
Panagiotis Symeonidis Alexandros Nanopoulos Apostolos N. Papadopoulos Yannis Manolopoulos 《Information Retrieval》2008,11(1):51-75
Collaborative Filtering (CF) Systems have been studied extensively for more than a decade to confront the “information overload”
problem. Nearest-neighbor CF is based either on similarities between users or between items, to form a neighborhood of users
or items, respectively. Recent research has tried to combine the two aforementioned approaches to improve effectiveness. Traditional
clustering approaches (k-means or hierarchical clustering) has been also used to speed up the recommendation process. In this paper, we use biclustering
to disclose this duality between users and items, by grouping them in both dimensions simultaneously. We propose a novel nearest-biclusters
algorithm, which uses a new similarity measure that achieves partial matching of users’ preferences. We apply nearest-biclusters
in combination with two different types of biclustering algorithms—Bimax and xMotif—for constant and coherent biclustering,
respectively. Extensive performance evaluation results in three real-life data sets are provided, which show that the proposed
method improves substantially the performance of the CF process.
相似文献
Yannis ManolopoulosEmail: |
86.
在软骨细胞自动分割计量系统的分割部分中,用Ostu法初步分割图像后,对轻度粘连细胞采用了形态滤波处理,利用细胞核信息进一步细化分割粘连较多的细胞,获得了较好的效果。 相似文献
87.
光散射法粒度测试涉及到粒度反演技术.随着反演粒级数的增加,通常的粒度反演法将出现严重的振荡.文章将Chahine迭代算法与平滑滤波技术相结合解决了高反演粒级数下数值解的振荡,在不改变激光粒度仪的原有结构情况下,就可明显提高仪器的精度和分辨能力. 相似文献
88.
Oyelami Olufemi Moses 《美中教育评论》2008,5(11):22-27
More recent motivational research focuses on the identification of effective techniques for enhancing instructional design and meeting the needs of diverse student populations (Wlodkowski R. J., 1981). Learning-motivation researchers are applying some of the same theories and concepts found to be effective in industry to the development of motivational models that enhance the teaching-learning environment. One of such models is the Attention Relevance Confidence Satisfaction (ARCS) model of motivational design developed by John M. Keller (Small Ruth V., 2007). The continuous improvement in handheld devices technologies has led to a new learning paradigm called mobile learning which involves the delivery of learning contents to learners utilizing mobile computing devices. Handheld devices, however, have constraints which limit their use for effective learning. Towards improving the effectiveness of mobile learning is a new mobile learning model proposed by Shih on which instructional designs for mobile learning can be based to facilitate mobile learning design and to achieve better mobile learning outcomes (Yushin E. Shih & Dennis Mills, 2007). Shih's model is based on Graphical User Interface (GUI). This paper presents an enhanced Shih's model for effective mobile learning outcome in a university environment by making provision for instructional design to include online library search for both e-books and audio books using collaborative filtering algorithm to aid the search and posting and reading of testimonials about positive mobile learning outcomes so as to encourage other mobile learners. It also incorporates the use of Voice User Interface (VUI) to access the learning portal in order to overcome mobile devices interface limitations in addition to Graphical User Interface (GUI) proposed by Shih, so as to cater for the learning needs of the blind and the visually impaired. 相似文献
89.
介绍了回声消除器的基本结构、回声路径的脉冲响应以及语音信号的特点,分析输入信号为白噪声、有色噪声和语音的情况下自适应算法的性能,在此基础上应用一种参数筛选更新归一化最小均方差(NLMS)算法以及基于互相关的双边对话侦测算法,并提供详细仿真结果。 相似文献
90.
利用智能微粒群算法(PSO)优化设计少片变截面弹簧代替原等截面板簧.文章通过ANSYS对其静态和动态特性进行有限元仿真分析,结果显示,在满足悬架性能条件下,质量比原板簧减轻了约31%. 相似文献