6 resultados para Wilson, Woodrow, 1856-1924.
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
考虑到环境压迫的因素,对PFU法中的MacArthur-Wilson平衡模型作了修改,推导出一个更为适用的新模型。小野外生态试验和室内毒理试验中提出4个功能参数(S_(eq),G,H,T_(90%))用于环境的生物监测。使用Monte Garlo序贯随机模拟算法和Marquardt算法估计模型参数并完成计算机程序的编制,最后还使用拟合差异度法检验实验模型。
Resumo:
ARP协议漏洞严重威胁着TCP/IP的安全,一些基于对称或非对称密钥机制的安全ARP协议被相继提出。本文介绍了ARP协议攻击的原理和几个最出名的基于对称或非对称密钥机制的安全ARP协议,引入Clark-wilson商业模型对ARP的完整性状态进行了分析,把改进协议Clark-Wilson模型化,在模型化的过程中找到了它们不能通过Clark-Wilson商业模型验证规则的关键点,并根据Clark-Wilson商业模型提出的经典场景,给出了相应的攻击场景。
Resumo:
商业应用需要实施完整性策略保护.Biba模型提供了一种简洁的多级完整性控制方案,但是需要引入可信主体来保证实施的可用性.而Clark-Wilson模型通过可监控的状态转换提供了一种完备的完整性保护,但其复杂性影响了该模型的完整实现.提出的模型以Biba严格完整性策略为基础,同时根据可信主体在其生命周期所属的状态实施Biba低水标策略.对可信主体在其生命周期发生的状态转换及相应的低水标参数调整,采用Clark-Wilson模型来进行监控.在有效解决了Biba策略的可用性问题和Clark-Wilson模型监控量过大给系统带来的配置和运行负担问题的同时,继承它们的优点.证明了该策略融合方案是可行的、安全的.
Resumo:
A new species, Axianassa sinica, from the Beibu Gulf (Gulf of Tonkin), northern South China Sea, is described and illustrated. The new species is readily distinguished from A. australis Rodrigues & Shimizu, 1992, by its acute rostrum, merus of pereopod 1 with a tooth distally on lower margin and an elongated telson.
Resumo:
The composition of the leaf oils from seven populations of J. sabina L., one population of Juniperus sabina var. arenaria (E. H. Wilson) Farjon were examined for their geographic variation. In addition, the leaf oils of J. chinensis L. and J. davurica Pall. were compared to J. sabina. Juniperus sabina var. arenarla, the sand loving juniper, oil was found to be very similar to that of J. davurica, Mongolia, and J. sabina, on sand dunes in Mongolia. This suggests that J. sabina var. arenaria might be conspecific with J. davurica. Farjon's move (2001) of J. sabina var. arenaria out of J. chinensis is supported. Considerable differentiation was found in populations of J. sabina from the Iberian peninsula. Cedrol, citronellol, safrole, trans-sabinyl acetate, terpinen-4-ol and beta-thujone were found to be polymorphic in several populations.