基于神经网络BP算法的出租汽车保有量预测法

介绍了出租车保有量神经网络预测模型的建立.以南京市的实际数据为检测依据,论证了该模型应用于城市出租汽车保有量预测的可行性,并对该市2005～2008年的出租汽车保有量进行了预测;该预测模型与传统模型进行预测对比的结果表明,由于神经网络在处理非线性系统方面的优越性,该预测模型在交通预测方面具有较高的计算精度.     

Improvements on Analytical Models for IEEE 802.11e EDCF Differential Services

Zhu introduced typical analytical models to simulate the 802. 11e EDCF channel access protocol. But our analysis indicates that there are some inaccurate derivations in his presentation. This paper intends to improve analytical model with some corrections. Furthermore, for the probability of the channel being busy pb in Zhu＇s model, different points and analysis method are proposed. When the network is under saturation condition, the new results about the probabilities of collision and channel busy, transmission probabilities, successful transmission probabilities, throughput and MAC layer latency are presented.     

省域高速公路网运营与服务信息化平台研究

高速公路网运营与服务的信息化是目前国内外研究和应用的热点问题。信息化平台的建设运营是涉及人、车、路、环境相互作用的复杂过程。本文以国内外高速公路信息化发展经验为鉴,以高速公路网运营与服务信息化中"人"的需求为导向,对信息化平台的服务对象进行归类,并分析各对象的数据和功能需求;分别从技术选择、系统开发、设计方法、平台建设四个方面,提出了信息化平台设计的原则;建立了"信息感知平台——数据中心——业务应用平台"的三层闭环式信息化平台架构,辅以标准体系和运行维护系统,以保障平台的有序和高效运行;在此基础上,提出了平台各组成部分的功能。     

Making Landfall: Linkages between Fishing Communities and Support Services

The relationship between the fishing industry and the fisheries-related support service sector creates economic benefits for communities through the strong linkages between fishermen and their land-based suppliers and the induced or multiplier effects from fisheries revenue. The support service sector is embedded within fishing communities where the impacts of fisheries management changes are perpetuated. This article examines the potential for such impacts by evaluating the diversity of fishing gear use, ex-vessel revenue, presence of processing plants, public moorage, and haul-out or tidal grids, and the number of vessels in a community, in relation to the availability of support services in communities in Alaska. The results show that the presence of a processor and haul-out facilities in a community significantly affects the number of support service businesses; however, there is not a strong association with the number of vessels or ex-vessel revenue. One hypothesis is that fishermen often travel to other communities to obtain services. We evaluate this hypothesis using social network analysis to evaluate transfers of revenue for fishery-related goods and services. Ultimately, this informs the exploration of the importance of support service businesses and fishery-support infrastructure to the continued well-being of fishing communities.