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Relations among Mobility Metrics in Wireless Networks
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作者 Xiao SHU xining li 《International Journal of Communications, Network and System Sciences》 2008年第3期246-253,共8页
In wireless network simulation analysis, researchers tweak mobility metrics, such as the speed or the pause time of the nodes, to get different stability levels of the network. Meanwhile, in theoretical analysis, link... In wireless network simulation analysis, researchers tweak mobility metrics, such as the speed or the pause time of the nodes, to get different stability levels of the network. Meanwhile, in theoretical analysis, link failure rate is widely used to model the stability of a wireless network. This paper presents an analysis of a simplified mobility model and shows that the link failure rate is positively correlated with the average speed of nodes in this model. Though this result is based on a mobility model with many restrictions, a simulation evaluation suggests that the result still holds in the popular random waypoint model and random direction model. Based on this observation, this paper also encourages the use of link failure rate as mobility metric instead of the problematic pause time in future practice. 展开更多
关键词 MOBILITY Metrics LINK FAILURE Rate Simulation
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A Scalable and Robust DHT Protocol for Structured P2P Network
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作者 Xiao Shu xining li 《International Journal of Communications, Network and System Sciences》 2012年第12期802-809,共8页
Distributed Hash Tables (DHTs) were originated from the design of structured peer-to-peer (P2P) systems. A DHT provides a key-based lookup service similar to a hash table. In this paper, we present the detailed design... Distributed Hash Tables (DHTs) were originated from the design of structured peer-to-peer (P2P) systems. A DHT provides a key-based lookup service similar to a hash table. In this paper, we present the detailed design of a new DHT protocol, Tambour. The novelty of the protocol is that it uses parallel lookup to reduce retrive latency and bounds communication overhead to a dynamically adjusted routing table. Tambour estimates the probabilities of routing entries' liveness based on statistics of node lifetime history and evicts dead entries after lookup failures. When the network is unstable, more routing entries will be evicted in a given period of time, and the routing tables will be getting smaller which minimize the number of timeouts for later lookup requests. An experimental prototype of Tambour has been simulated and compared against two popular DHT protocols. Results show that Tambour outperforms the compared systems in terms of bandwith cost, lookup latency and the overall efficiency. 展开更多
关键词 P2P Network Distributed HASH TABLE SMALL-WORLD Distribution Parallel Lookups
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A grounded theory research on public librarians’ percep-tion of organizational cultures
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作者 Ping KE Wenliang ZHANG +1 位作者 xining li Chengxiu TANG 《Journal of Library Science in China》 2014年第1期40-57,共18页
This research is a case study of Shandong Public library with the application of a grounded theory to identify the perceived dimensions and the theoretical framework of organizational culture in the view of librarians... This research is a case study of Shandong Public library with the application of a grounded theory to identify the perceived dimensions and the theoretical framework of organizational culture in the view of librarians.Research found two dimensions which were internal cultural perception and external cultural perception.In the internal cultural perception,there include two notion areas,which are career orientation and personal characteristics of the individual;in the external cultural perception,there include five notion areas,which are social environment,architecture,systems,tasks and leadership.The theoretical framework of mechanisms of public librarians’ perception of organizational cultures is constructed.The study found two mechanisms of the dynamic evolution of organizational culture of public libraries:the first is the mechanism of individual internalization of cultures,and the other is the mechanism of the person-culture fit. 展开更多
关键词 LIBRARIES ORGANIZATIONAL CULTURE Grounded THEORY
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Location layout design of aircraft parts assembly based on MSVR 被引量:7
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作者 xining li Zhihao ZHAO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第5期1532-1540,共9页
Location layout of aircraft assembly is an important factor affecting product quality.Most of the existing re-searches use the combination of finite element analysis and intelligent algorithm to optimize the location ... Location layout of aircraft assembly is an important factor affecting product quality.Most of the existing re-searches use the combination of finite element analysis and intelligent algorithm to optimize the location layout,which are limited by numerical simulation accuracy and the selection and improvement of intelligent algorithms.At present,the analysis and decision-making technology based on field data is gradually applied in aircraft manufacturing.Based on the perception data of intelligent assembly unit of aircraft parts,a regression model of multi-input and multioutput support vector machine with Gauss kernel function as radial basis function is established,and the hyperparameters of the model are optimized by hybrid particle swarm optimization genetic algorithm(PSO-GA).GA-MSVR,PSO-MSVR and PSOGA-MSVR model are constructed respectively,and their results show that PSOGA-MSVR model has the best performance.Finally,the design of the aircraft wing location layout is taken as an example to verify the effectiveness of the method. 展开更多
关键词 Aircraft parts ASSEMBLY Hybrid particle swarm optimization genetic algorithm Location layout Multi-output support vector regression(MSVR) Perception data
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