Experimental Investigation on Transmission Control Protocol Throughput Behavior in Optical Fiber Access Networks

ABSTRACT

This article describes an experimental investigation on the behavior of transmission control protocol in throughput measurements to be used in the verification of the service-level agreement between the Internet service provider and user in terms of line capacity for ultra-broadband access networks typical of fiber-to-the-x architectures. It is experimentally shown different conditions in high bandwidth-delay product links where the estimation of the line capacity based on a single transmission control protocol session results are unreliable. Simple equations reported in this work, and experimentally verified, point out the conditions in terms of packet loss, time delay, and line capacity, that allow consideration of the reliability of the measurement carried out with a single transmission control protocol session test by adopting a suitable measurement time duration.     

Tahoe TCP拥塞控制算法研究和改进

分析了网络拥塞的基本知识,具体研究了Tahoe TCP拥塞控制算法和加入了新的慢启动策略的Reno TCP算法,并且通过网络仿真试验比较其性能。     

Stress generation during anisotropic lithiation in silicon nanopillar electrodes: A reactive force field study

Models that are developed to investigate lithiation-induced stress in high-volume-change electrodes are often based on continuum approaches with simplifying assumptions. In this work, we investigate stress generation during the first lithiation of crystalline silicon electrodes solely using atomistic simulations with chemo-mechanical fidelity. We use a 〈100〉-oriented silicon nanopillar as a model system and perform molecular statics simulations with a reactive force field. The simulation approach incorporates the key physical feature of the lithiation – anisotropic formation and migration of an atomistically-sharp phase boundary. The resulting stress fields show the development of hoop tension near the nanopillar surface, which drives surface fracture at angular sites between two adjacent {110} facets. This work links the atomic-level physics of the lithiation directly with the stress generation and accounts for the geometric effect of the sharp phase boundary.     

机会网络中基于传染路由的TCP性能分析

不同于传统互连网络,机会网络具有时延长、数据率低和间断连接等特性,其以＂存储-携带-转发＂的路由模式来实现节点间通信,其研究重点是基于冗余的机会网络路由协议.为了研究机会网络中TCP的性能,特别是与传染路由结合时的TCP性能,通过对机会网络使用不同路由时TCP的性能进行对比仿真,分析了TCP与传染路由结合的可行性.仿真结果表明：传染路由在一定条件下能与TCP结合,但传染路由的＂洪泛＂特性和机会网络的间断特性会使得TCP性能较差.     

Photosolvolysis of 3,4-dichloroaniline in water : Evidence for an aryl cation intermediate

Irradiation of 3,4-dichloroaniline in water (λ > 290nm) gave 2-chloro-5-aminophenol with a conversion of 78±5%. The photolysis quantum yield at 313 nm of 0.052±0.003 was unaffected by cyanide (0.35 M) or pH changes between 4 and 12. A MO calculation indicated a large excited singlet state shift in electron density to the carbon undergoing substitution. The reaction is suggested to proceed through an aryl cation intermediate produced by heterolytic cleavage of the meta carbon-chlorine bond. Reaction from the triplet state is not considered likely since neither oxygen nor sorbic alcohol affected the quantum yield.