Noisy chaotic neural network for resource allocation in high-speed train OFDMA system     

赵宜升  纪红  陈忠辉 《天津大学学报(英文版)》2014,20(5):368-374

High-speed train communication system is a typical high-mobility wireless communication network. Resource allocation problem has a great impact on the system performance. However, conventional resource allocation approaches in cellular network cannot be directly applied to this kind of special communication environment. A multidomain resource allocation strategy was proposed in the orthogonal frequency-division multiple access （OFDMA） of high-speed. By analyzing the effect of Doppler shift, sub-channels, antennas, time slots and power were jointly consid- ered to maximize the energy efficiency under the constraint of total transmission power. For the purpose of reducing the computational complexity, noisy chaotic neural network algorithm was used to solve the above optimization problem. Simulation results showed that the proposed resource allocation method had a better performance than the traditional strategy.  相似文献   

开放获取S计划演进历程、动因及对我国的启示     

崔丽媛  刘春丽 《图书情报工作》2021,65(4):102-110

[目的/意义] 以利益相关者——科学共同体为视角,分析S计划的政策演变,及对我国开放获取实践发展的启示。[方法/过程] 运用文献调研法与内容分析法,追踪S计划的演进历程,对标志性事件的发生时间节点、内容及相关政策进行分析;梳理S计划的最新动态,包括S计划对科学共同体影响的监控框架、权利保留政策及钻石开放获取的新模式。[结果/结论] 聚焦政策的深层解读并挖掘内在动因,包括S计划被科学共同体的采纳受到资历、国别、学科的影响;科学共同体难以进行绿色开放获取存储;难以识别“掠夺性期刊”;影响学术出版自由选择。最后提出设置开放获取专员、制定APC相关政策、强化期刊出版机构质量管理、推进机构知识库的常态化建设等措施,以期对我国开放获取实践提供借鉴与参考。  相似文献   

信息网络安全创新接入认证模型方案的构建与实现     

张国柱 《天津职业技术师范学院学报》2014,(1):25-27,32

研究了网络安全领域可信网络概念和认证接入技术,提出了基于可信网络的新型接入认证模型,利用安全评估接入网络终端的方式可对网络访问进行有效控制,将网络安全威胁隔离在网络之外,构建一个安全、稳定、可靠的网络环境,减少网络安全事件发生的概率,同时支持802.lx、VPN和WAPI等网络接入技术,提高了其应对网络安全威胁的能力.  相似文献   

我国化学类中文核心期刊开放存取现状与分析     

杨珠 《福建师大福清分校学报》2014,(5):65-70

基于2011年版《中文核心期刊要目总览》中收录的化学类核心期刊,搜索并统计分析了我国化学类中文核心期刊开放存取的现状。结果表明:64.00%的期刊在自身的期刊网站实现了开放存取;回溯时间在1980-1989年的期刊数量最多(81.00%),81.25%的期刊回溯至创刊年;多数期刊开放了创刊年至今的全部期刊;75.00%的期刊网上开放全文与印刷版期刊同步,25.00%的期刊网上开放全文滞后于印刷版期刊1期,31.25%的期刊提供了网络预出版的文章;开放全文的格式以PDF格式为主;期刊的检索方式多元化。认为化学类期刊办刊者应加强开放存取理念、缩短开放存取时滞并提高文献检索效果。  相似文献   

Personal learning environments: design and use / Los entornos personales de aprendizaje en la educación superior: del diseño al uso     

César Coll  Anna Engel  Alexandra Saz  Alfonso Bustos 《Cultura y Educación》2014,26(4):775-801

Abstract

This study focuses on the uses that two groups of higher education students make of technological resources offered by an institution to build their own personal learning environments. The main thesis is that these uses depend on the techno-pedagogical design of the teaching and learning process in which the technological resources are framed. In order to explore and illustrate this thesis two instructional sequences have been analysed. Both use the same technological design, the Elgg platform, which allows users to select and organize a set of resources or widgets according to their interests and needs. The results show that in both cases the uses that students make of technology are related to the characteristics and requirements of the particular techno-pedagogical designs. We conclude that the key is not to offer technological resources to the students so they can build their own personal learning environments, but to design activities that attract and induce them to build these personal environments and to guide and support the process of construction.  相似文献   

云计算安全研究     

庄金莲  周志平 《泉州师范学院学报》2014,(2):96-99

为解决云计算平台的安全问题,对云计算的安全架构进行了系统的研究．针对云计算平台跨区域模糊边界、虚拟化服务、数据保密的安全威胁特点,从虚拟化技术、可信云计算、可信访问控制机制三个层面深入分析云计算安全框架,并提出云计算平台的安全策略与建议,满足云计算安全框架的建设需求．  相似文献   

Web Accessibility Assessment of Urban Public Library Websites     

Stephanie L. Maatta Smith 《Public Library Quarterly》2014,33(3):187-204

In an age of ubiquitous information and communication technologies, urban public libraries are some of the only places to provide free Internet access for all members of the community regardless of ability or disability. This study provides a website accessibility assessment of the 127 U.S. public library members of the Urban Library Council, using the World Wide Web Consortium’s Web Content Accessibility Guidelines to establish the level of Web readiness of urban public libraries to meet the needs of individuals with disabilities. Findings suggest these libraries require additional and ongoing maintenance to be digitally inclusive.  相似文献   

Designing User-Centered Discovery and Access Services for Enhanced Virtual User Experience     

Paoshan W. Yue  Amalia K. Beisler 《期刊图书馆员》2014,66(1-4):268-277

In 2010, the Technical Services Department at the University of Nevada, Reno Libraries established its top strategic direction to understand users’ workflows and strive to build seamless information access services around their workflows. To advance this strategic direction, an innovative reorganization was implemented within Technical Services by creating a new Knowledge Access and Discovery (KAD) Librarian position and forming a new Design and Discovery (DD) department from existing staff. In this session, the presenters discussed the shift to user-centered services, the roles of the KAD Librarian and the new DD department, their projects and initiatives, and how they work with the library-wide cross-departmental Virtual User Experience Committee to meet the Internet-fueled do-it-yourself (DIY) mindset of today’s library users.  相似文献   

《PLOS ONE》开放获取出版模式研究     

韩婧 《编辑学报》2014,26(2):202-204

以PLoS旗下的在线期刊《PLOS ONE》为例,从同行评审制度、经费来源、版权问题、评价方式等方面研究其开放获取出版模式。其中,同行评审与先发表后评价共存的评价模式,尤其值得我国科技期刊界思考和借鉴。  相似文献   

图书馆广域网接入高可用架构的技术分析     

郑晓军 《江西图书馆学刊》2014,(2):12-15

在广域网应用已成为图书馆业务工作不可或缺的今天,广域网接入布局高效率、高安全的架构可以避免网络攻击、设备故障等突发事件,确保图书馆业务工作能够持续地进行。  相似文献