基于视觉暂留的验证码设计     

门涛 《乐山师范学院学报》2013,28(5):43-45

验证码能够有效抵御网络中机器程序的自动登录行为,防止机器程序群发垃圾邮件和自动投票等非法行为。但是随着图像识别技术和人工智能的发展,传统的验证码面临着被机器程序自动破解的危险。文章在分析不同验证码的优缺点后,提出一种基于人眼视觉暂留现象的动态验证码,利用有效字符和干扰字符混合组成多帧动态图像,普通用户可以轻易识别,而机器程序难以区分,理论分析和模拟实验证明该验证码简单有效。  相似文献   

The zone of proximal creativity: What dynamic assessment of divergent thinking reveals about students’ latent class membership     

《Contemporary educational psychology》2021

Divergent Thinking is a domain-general mental attribute closely associated with creativity that can be quantified through the use of text-mining algorithms. Past research has shown that students’ Divergent Thinking is malleable in response to relatively simple contextual prompts. In addition, there is substantial variance in the degree to which individual students’ Divergent Thinking is malleable, suggesting the presence of a student-specific zone-of-proximal-development in relation to creativity. Here, we adopted a dynamic assessment paradigm that included multiple conditions under which student Divergent Thinking was measured and fit a latent profile analysis model to that dynamic assessment data. We found that, although on average the Originality of student responses can be augmented through a prompt to generate surprising or unusual ideas, three latent classes emerged that differed significantly on their patterns of augmentation. These three latent classes were termed: (a) Conventional Thinkers (7.80% of the sample), whose response to the Divergent Thinking task were highly constrained and unoriginal across all conditions (b) Prompted Shifters (66.56%), whose Originality significantly increased across conditions, and (c) Idea Generators (25.64%), whose responses were highly original across all conditions. These latent profiles were validated in regard to personality characteristics and domain-specific creative activities, with Idea Generators reporting significantly more Openness and Intellect, less Industriousness, and more creative activities across the domains of Literature, Music, Sports, Visual Art, Science, and Cooking than did the other latent classes.  相似文献   

Swarm intelligence goal-oriented approach to data-driven innovation in customer churn management     

《International Journal of Information Management》2021

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The Effect of a Computerized Simulation on Middle School Students’ Understanding of the Kinetic Molecular Theory     

Luli Stern  Nitza Barnea  Sofia Shauli 《Journal of Science Education and Technology》2008,17(4):305-315

The objective of this study was to evaluate the effect of a dynamic software simulation on the understanding of the kinetic molecular theory by 7th graders. Students in the control group (n = 62) studied a curricular unit that addressed the differences in arrangement and motion of molecules in the three phases of matter. The experimental group (n = 71) studied the same unit combined with a few computer lessons using a software simulation. The results indicate that the students in the experimental group scored significantly higher than those in the control group. Nonetheless, while both groups of students improved their understanding of the kinetic molecular theory, the overall achievements were very low. These findings suggest that the simulation improved the understanding of the 7th graders; however, it was insufficient in itself to promote meaningful learning. Statistically significant gender differences were not observed. This paper concludes with a discussion of the educational implications of this study.  相似文献   

脉动式CVT连杆机构的运动规律研究     

冯士活 《浙江工贸职业技术学院学报》2008,8(1):37-42

本文对曲柄摇块式脉动无级变速的传动机构进行了运动分析,从运动学原理对机构进行深入研究,得出该机构的最佳参数,减小脉动及动载荷,降低功率损耗,进而改善其运动及动力性能,  相似文献   

改进蚁群算法的动态K-均值聚类分析     

匡青  鲍梦 《教育技术导刊》2008,(1)

提出了一种基于改进蚁群算法的动态K-均值聚类算法思想,该算法首先利用蚁群算法的较强处理局部极值的能力,动态地确定了聚类数目和中心,然后利用蚁群聚类得到的结果,再进行K-均值聚类弥补蚁群算法的不足。两者有机结合起来可以寻求到具有全局分布特性的最优聚类,实现了基于改进的蚁群聚类算法分析。  相似文献   

基于构件技术的一种报表生成器的设计     

郑婕  王平  肖斌 《九江职业技术学院学报》2008,(2):29-31

本文为动态生成需要的报表提出了构件技术的概念,使得可以通过构件技术制作报表。并且根据这种思想,建立了制作报表的模式,开发出基于构件技术的动态报表生成器,实现了报表的构件化管理和重用,实现了一表万用。  相似文献   

Dynamic response analysis of a moored crane-ship with a flexible boom   总被引：3，自引：0，他引：3  

Hui-li Ren  Xue-lin Wang  Yu-jin Hu  Cheng-gang Li 《浙江大学学报(A卷英文版)》2008,9(1):26-31

The dynamic response of moored crane-ship is studied. Governing equations for the dynamic response of a crane-ship coupled with the pendulum motion of the payload are derived based on Lagrange＇s equations. The boom is modeled based on finite element method, while the payload is modeled as a planar pendulum of point mass. The dynamic response was studied using numerical method. The calculation results show that the large-amplitude responses occur at wave periods near the natural period of the payload. Load swing angle is smaller for crane-ship with flexible boom, in comparison with rigid boom. The ship surge motions have large vibrations for crane-ship with flexible boom, which were not observed for a rigid boom. The analysis identifies the significance of key parameters and reveals how the system design can be adjusted to avoid critical conditions.  相似文献   

以“感性”中和“理性”的物理活力教学新渠道     

孙香琪  张勇 《天津教育》2021,(5):33-34

物理是一门以“理性”和“严谨”为标识的科学,因此,学习物理需要缜密集中的思维逻辑力,物理课堂教学需要更多的“理性化”的特点。但感性是人类认识活动的起点,加之物理的本源及物理规律与人类生活经验有密切的联系,“感性”便可成为高中物理教育的一个新朝向,而通过视频展示、人文诠释、活动体验和实验操作这四种方式可以激活物理课堂,渗透“理性”思维,从而实现课堂活力的充分迸发。  相似文献   

论数字图书馆如何实施动态库服务     

王金刚 《现代情报》2007,27(2):95-96

拟结合相关的软件技术,就网络环境下,现代图书馆向数字图书馆迈进的进程中,如何实施动态库服务问题略抒己见。  相似文献