检索结果-南通市图书馆

Design and Optimization of VLC Enabled Data Center Network

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2020年第1期25卷 81-92页

作者： Yudong Qin Deke Guo Xu Lin geyao cheng Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410073China School of Computer Science and Technology Xidian UniversityXi’an 710000China

Visible-Light Communication(VLC) has the potential to provide dense and fast connectivity at low cost. In this paper we propose SFNet, a novel VLC-enabled hybrid data center network that extends the design of wireless Data Center Networks(DCNs) into three further dimensions:(1) fully wireless at the inter-rack level;(2) no need for a centralized control mechanism on wireless links;and(3) no need for any infrastructure-level alterations to data centers. Previous proposals typically cannot realize these three rationales simultaneously. To achieve this vision,the proposed SFNet augments fat-tree by organizing all racks into a wireless small-world network via VLC links. The use of VLC links eliminates hierarchical switches and cables in the wireless network, and thus reduces hardware investment and maintenance costs. To fully exploit the benefits of the topology of SFNet, we further propose its topology design and optimization method, routing scheme, and online flow scheduling algorithm. Comprehensive experiments indicate that SFNet exhibits good topological properties and network performance.

关键词： Data Center Network(DCN) Visible Light Communication(VLC) topology design

Design and optimization of VLC based small-world data centers

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2019年第5期13卷 1034-1047页

作者： Yudong QIN Deke GUO Lailong LUO geyao cheng Zeliu DING Science and Technology on Information System Engineering Laboratory National University of Defense Technology Changsha 410073 China School of Electronic Engineering Naval University of Engineering Wuhan 430033 China

The visible light communication (VLC) has the potential to provide dense and fast connectivity at low cost. In this paper, we propose a novel VLC enabled Wireless Small-World Data Center (WSWDC). It employs VLC links to achieve a fully wireless data center network (DCN) across racks for the first time. The using of VLC links eliminates hierarchical switches and inter-rack cables, and thus reducing hardware investment, as well as maintenance cost. More precisely, to simplify the configuration and control operations, we propose three DCN design rationales:(1) fully-wireless, all inter-rack links are wireless;(2) easy-deployable, it is not necessary to change the existing infrastructure inside data center;(3) plug-and-play, no extra centralized control operations are required. Previous proposals, however, cannot achieve the three rationales simultaneously. To this end, we first use regular VLC links to interconnect racks as a regular grid DCN and optimize the rack placement to shorten the average path length and the network diameter. To further exploiting the benefits of VLC links, a few random VLC links are carefully introduced to update the wireless grid DCN as a wireless small-world DCN. To avoid the potential interference among VLC links, we deploy VLC transceivers at different heights on the top of each rack. In this way, VLC links would not interfere with others at each height level. Moreover, we design a greedy but efficient routing method for any pair of racks using their identifiers as inputs. Comprehensive evaluation results indicate that our WSWDC exhibits good topological properties and network performance.

关键词： data center network visible light communication small-world wireless links topology design

研究生压力知觉对生活满意度的影响：孤独感的中介作用

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

现代医学 2024年第7期52卷 1018-1023页

作者：杨婷周戈耀陈思银程远芬杨娟华李丹曹煜贵州医科大学公共卫生与健康学院环境污染与疾病监控教育部重点实验室贵州医科大学大健康研究院

目的:探讨硕士研究生孤独感在压力知觉与生活满意度之间的关系和作用机制。方法:采用孤独感量表、压力知觉量表以及生活满意度量表对728名统招硕士研究生进行问卷调查，运用SPSS 25.0统计软件对数据进行独立样本t检验、方差分析、Pearso... 详细信息

目的:探讨硕士研究生孤独感在压力知觉与生活满意度之间的关系和作用机制。方法:采用孤独感量表、压力知觉量表以及生活满意度量表对728名统招硕士研究生进行问卷调查，运用SPSS 25.0统计软件对数据进行独立样本t检验、方差分析、Pearson相关分析、多元回归分析，使用AMOS 26.0软件构建结构方程模型并进行评估。结果:(1)压力知觉、孤独感与生活满意度均呈负相关(r=-0.519、-0.440,均P<0.01);压力知觉与孤独感呈正相关(r=0.568,P<0.01)。(2)压力知觉可以直接预测生活满意度(β=-1.217,t=-16.349,P<0.001),孤独感在压力知觉与生活满意度之间起部分中介作用，其中直接效应为-0.931,间接效应为-0.285,中介效应占总效应的23.45%。结论:压力知觉既能够直接影响生活满意度，也能够通过孤独感的中介作用影响生活满意度。

关键词：压力知觉孤独感生活满意度硕士研究生

在线全文

学校读者我要写书评

暂无评论

宋代龙泉青瓷的研究

陶瓷学报 1999年第2期20卷 64-78页

作者：叶宏明李国桢郭演仪周绍达叶培华胡兆雄沈世耕叶国珍曹鹤呜程朱海中国硅酸盐学会陶瓷分会

研究了在浙江龙泉大窑地区窑址群中出土的质量很高的南宋哥窑和弟窑瓷片胎、釉的化学组成、显微结构和烧制工艺，分析了影响青瓷釉呈色的基本因素，讨论了青瓷釉“开片”、“鸡爪纹”、“朱砂底”、“紫口铁足”的主要成因，论证了哥。

关键词：古陶瓷龙泉青瓷工艺陶瓷宋代瓷器