动态雾计算网络中基于在线学习的任务卸载算法     

谭友钰  陈蕾  周明拓  王昆仑  杨旸  张武雄 《中国科学院大学学报》2020,37(5):688-698

任务卸载是雾计算的主要技术之一，即计算能力不足的节点将任务卸载给具有富余资源的节点帮助计算。以优化任务平均卸载时延和提升卸载服务成功率为目标，利用多臂老虎机理论为动态雾计算网络提出一种基于在线学习的任务卸载算法，可实时做出最优卸载决策。将该算法扩展到非稳定网络状态，使之可以动态追踪网络中节点的资源与环境变化，实时调整卸载决策。详细分析所提出算法的性能、复杂度和存储占用情况。仿真结果表明，这两种算法可达到的长期平均任务卸载时延均十分接近理想算法下的最优时延，卸载服务成功率也得到显著提升。此外，所提算法在非稳定的网络状态下能够追踪到计算资源与环境的变化。  相似文献   

English in Education: the first fifty years     

John Hodgson  Sarah Wilkin 《English in Education》2014,48(3):196-229

On the fiftieth anniversary of the first publication of English in Education, this article reviews the journal's contribution to research and practice in the teaching of English. A thematic analysis based on close study of a sample of volumes is arranged chronologically (to show the development of ideas and practices) and thematically in terms of language mode (speaking; writing; reading, including new technologies). The article argues that the journal archive can shed light on the educational past in ways that can effectively inform the educational present and help to set agenda for the future.  相似文献   

常用数值并行算法的研究与应用     

李戈  崔会军 《河北旅游职业学院学报》2016,(2):86-88

本文详细的介绍了MPI并行程序编程实现和设计方法，针对常用数值进行并行运算求解，主要是解决了如何用布尔积求幂矩阵判断各顶点之间是否可达，同时推算出经过多少（个顶点）条边才能到达这两个问题。最后对并行程序进行测试分析，并总结了本论文所做的工作中的经验与不足，并指出需要继续研究的问题。  相似文献   

Exploring an intervention’s impact on everyday school activities     

Marianne Björn  Idor Svensson 《Support for Learning》2021,36(1):5-19

The focus of this paper is on a group of pupils with reading and writing difficulties who have been participating in an intervention study using assistive technology. That intervention study contained supervised training sessions with reading and writing tasks using an iPad with special supportive applications. The current study is a qualitative investigation of whether there has been any transfer from the intervention, to the pupils’ everyday school activities. Interviews with pupils and their teachers and observations during classroom lectures have been used to collect data. The results show that the pupils were positive to the assistive technology (the applications on the iPads), they found the apps easy to learn how to use and they appreciated the benefits they could give. Even so, only a few of the pupils had found use for and continued to use the tools after the intervention period finished. Possible reasons are that when the novelty wore off, students reverted to their usual study habits and that older students with many teachers and different classrooms were less able to adapt to using the apps. To improve transfer, it is suggested to introduce assistive technology earlier to students, in the younger grades, before study habits have been formed and to inform teachers about the use of AT in the classroom, including what is available and how it can benefit students.  相似文献   

利用AIS数据计算港口间竞争度的方法     

向哲  施朝健  胡勤友  杨春 《上海海事大学学报》2016,37(1):60-64

为能更有效地提供有价值的航运情报, 借鉴网络分析法相关原理，挖掘船舶AIS数据，获取港口之间的竞争度.该法通过船舶数据模型、港口数据模型、船舶抵达港口事件模型、船舶挂靠港记录、港口之间运力、港口网络等建立港口间竞争度模型. 选取2014年4—8月中国沿海船舶AIS数据和17个主要港口数据，利用模型计算出对上海港竞争度排名前三的港口依次是宁波港、张家港港和南通港.  相似文献   

基于消费者低碳偏好的供应链碳减排策略     

熊榕  梁承姬  韩婷婷 《上海海事大学学报》2019,40(4):52-60

针对一个占主导地位的零售商和两个制造商(名牌产品和普通产品制造商)组成的二级供应链,考虑制造商之间的定价顺序和低碳偏好消费者对普通产品的接受度,分别构建普通产品制造商采用或不采用减排技术情景下的收益模型,得出各情景下最优零售价格和收益。研究发现:零售商选择销售哪种产品与顾客对普通产品的接受度有关;普通产品制造商的减排策略主要取决于减排成本。在相同减排策略下,若顾客对普通产品接受度较大,制造商同时定价时产品的最优零售价小于等于不同时定价时产品的最优零售价,而同时定价时制造商的最优收益大于等于不同时定价时的最优收益,因此两个制造商应同时定价以获得更大的收益。  相似文献   

信息技术与新型教学模式的构建     

黄军鹰 《实验室研究与探索》2011,(7)

随着信息技术的进步,结合传统教学、实践教学和实验教学模式进行的新型教学模式出现,各种媒体被先后运用到了教学中,使教学变得灵活多样,丰富了课堂教学方式,提高了教学质量。以计算机为中心的互联网、多媒体技术的崛起,给现代教育注入了新的生命,在教育体制、教育方针、教育模式等各方面带来巨大的变革。从理论与现实的角度对信息技术在教学模式中所起的重大作用做出梳理,并指明新型教学模式实现的途径。  相似文献   

Exploring Developmental Appropriateness of Multitouch Tables in Prekindergarten: A Video Analysis     

Jennifer Ward  Stephanie Branson  Megan D. Cross  Ilene R. Berson 《Journal of Research on Technology in Education》2016,48(3):227-238

This study explored how developmentally appropriate practices influenced the affordances of a multitouch surface in an early childhood classroom. Children, ages 4 to 5 years old, were videotaped while engaged in a storymaking application on a multitouch table. As a result of the study, we found that some challenges with the functionality undermined children's autonomous control. The researchers observed numerous instances of issues with control of the medium, including height of the table, sensitivity to multiple types of touch, and limited instructions and prompts. Implications for future research and practice are discussed.  相似文献   

A Process for Reviewing and Evaluating Generated Test Items     

Mark J. Gierl  Hollis Lai 《Educational Measurement》2016,35(4):6-20

Testing organization needs large numbers of high‐quality items due to the proliferation of alternative test administration methods and modern test designs. But the current demand for items far exceeds the supply. Test items, as they are currently written, evoke a process that is both time‐consuming and expensive because each item is written, edited, and reviewed by a subject‐matter expert. One promising approach that may address this challenge is with automatic item generation. Automatic item generation combines cognitive and psychometric modeling practices to guide the production of items that are generated with the aid of computer technology. The purpose of this study is to describe and illustrate a process that can be used to review and evaluate the quality of the generated item by focusing on the content and logic specified within the item generation procedure. We illustrate our process using an item development example from mathematics drawn from the Common Core State Standards and from surgical education drawn from the health sciences domain.  相似文献   

科学技术支撑酒店安全的作用机制与保障体系研究     

林军华 《闽江学院学报》2011,32(6):77-81

信息资讯技术的飞跃式发展对现代酒店安全管理提出了巨大的挑战,特别是酒店安全问题越来越受到旅游者的重视,由于显性和隐性的安全隐患来源渠道广泛,使得酒店安全控制与管理变得更为复杂和困难,同时也对酒店安全管理的科技支撑提出越来越高的要求。鉴于此,我们应从酒店安全管理实践的角度出发,对酒店安全管理和科学技术支撑的内在共生性进行分析,构建科学技术支撑酒店安全的作用机制模型,并进一步完善科学技术支撑酒店安全的保障体系,以期能够为酒店安全管理和控制提供一定的借鉴意义,从而促进酒店业的健康、稳定和持续发展。  相似文献