Comparative Study of Different Adaptive Window Protocols

We study an Adaptive Window Protocol (AWP) with general increase and decrease profiles in the presence of window dependent random losses. We derive a steady-state Kolmogorov equation, and then obtain its solution in analytic form for particular TCP versions proposed for high speed networks, such as Scalable TCP and HighSpeed TCP. We also relate window evolution under an AWP to workload process in queueing systems; this observation gives us a way to compare various AWP protocols.     

Moist-Electric Generator with Efficient Output and Scalable Integration Based on Carbonized Polymer Dot and Liquid Metal Active Electrode

Moisture-enabled electricity generation (MEG) is highly promising in next-generation energy conversion. However, the practical applications of existing MEG devices are limited due to their low current and voltage outputs, strong dependence on high moisture, and inflexible nature. Herein, an efficient MEG integrated with flexible, all-weather, and scalable fabrication characteristics based on the rational combination of carbonized polymer dots (CPDs) and liquid metal (LM) active electrodes is developed for the first time. Remarkably, the fabricated MEG device can produce a stable voltage output of 800 mV and a record high current density of 1640 µA cm⁻². Even at a low air humidity of 15%, the MEG device can provide a high voltage output of 0.65 V and a considerable current density of 12 µA cm⁻². The prompted diffusion of hydrogen ions in CPDs and the additional metal ions ionized from the LM electrode contribute synergistically to the high electricity generation. Additionally, the device can be easily integrated on various flexible substrates and generate an ultrahigh voltage of 210 V to power commercial electronics, showing great potential in large-scale fabrication and application.     

Organocatalytic and Scalable Synthesis of the Anti‐Influenza Drugs Zanamivir,Laninamivir, and CS‐8958

Zanamivir, laninamivir, and CS‐8958 are three neuraminidase inhibitors that have been clinically used to combat influenza. We report herein a novel organocatalytic route for preparing these agents. Only 13 steps are needed for the assembly of zanamivir and laninamivir from inexpensive D ‐araboascorbic acid by this synthetic route, which relies heavily on a thiourea‐catalyzed enantioselective Michael addition of acetone to tert‐butyl (2‐nitrovinyl)carbamate and an anti‐selective Henry reaction of the resulting Michael adduct with an aldehyde prepared from D ‐araboascorbic acid. The synthetic procedures are scalable, as evident from the preparation of more than 3.5 g of zanamivir.     

Ultrafast,Low‐Cost,and Mass Production of High‐Quality Graphene

Fast, mass, and low‐cost production of high‐quality graphene, which is alluring, remains a great challenge, even though some approaches have shown potential for mass synthesis of graphene. Very recently a great breakthrough was made by Tour and co‐workers (Nature 2020, 577, 647–651): in just a second, easily exfoliated and highly crystalline graphene was produced from abundant carbon‐containing species by cost‐effective flash Joule heating with a low energy input of 7.2 kJ per gram graphene. Such an ultrafast, economic, and scalable process for high‐quality graphene production can be considered as a milestone in the graphene field and is highlighted in this article.     

基于SVG的图形化网络拓扑显示模块设计

网络拓扑的图形显示对实现网络管理系统的可视化和人机交互有着重要意义.将SVG(可伸缩矢量图形)引入网络拓扑管理模块,给出了基于SVG的图形化网络拓扑显示系统模型,并分别就数据解析、图形显示给出了具体模块设计和实现方案.该系统运用于网络管理系统后,可极大改善网管系统软件的用户界面,提高图形化网络拓扑的更新速度,便于集成其他网络管理功能模块.     

基于感知的右视点质量可分级编码算法

为了减少立体视频传输如此庞大的数据量,根据人眼的立体掩蔽效应,提出了基于感知的右视点质量可分级编码算法．该算法将宏块分为3类：平坦块、纹理块和边缘块,通过不同的量化步长使得右视点图像块的质量可分级．实验证明根据左视点的图像质量,右视点在人眼感知范围内码率减少25％～37％．该算法能在人眼主观察觉范围内很好地提高码率,进一步消除人眼立体视觉冗余．     

Error Concealment Using Inter‐layer Correlation for Scalable Video Coding

In this paper, we propose a new error concealment (EC) method using inter‐layer correlation for scalable video coding. In the proposed method, the auxiliary motion vector (MV) and the auxiliary mode number (MN) of intra prediction are interleaved into the bitstream to recover the corrupted frame. In order to reduce the bit rate, the proposed method encodes the difference between the original and the predicted values of the MV and MN instead of the original values. Experimental results show that the proposed EC outperforms the conventional EC by 2.8 dB to 6.7 dB.     

Comparing the streaming of FGS encoded video at different aggregation levels: frame,GoP, and scene

Fine granularity scalability (FGS), a new coding technique that has recently been added to the MPEG‐4 video coding standard, allows for the flexible scaling of each individual video frame at very fine granularity. This flexibility makes FGS video very well suited for rate‐distortion optimized streaming mechanisms, which minimize the distortion (i.e. maximize the quality) of the streamed video by transmitting the optimal number of bits for each individual frame. The per‐frame optimization of the transmission schedule, however, puts a significant computational burden on video servers and intermediate streaming gateways. In this paper we investigate the rate‐distortion optimized streaming at different video frame aggregation levels. We find that compared to the optimization for each individual video frame, optimization at the level of video scenes reduces the computational effort dramatically, while reducing the video quality only very slightly. Copyright © 2005 John Wiley & Sons, Ltd.     

基于模型的H263＋可扩展性编码

提出了基于模型的视频时空可扩展性编码方法，即根据人眼视觉敏感程度的不同，将视频中的每帧图象根据模型划分为程度不同的区域，对每一个区域分配不同的时间和空间分辨率，以期在极低码率的传送环境中保证人眼敏感区域的图象质量和传送效率。     

可扩展的冲击—接触并行计算研究

冲击—接触计算模型在汽车碰撞、金属成型等的模拟计算中有着广泛的应用，鉴于冲击—接触计算过程复杂和计算量大，本文在分布式可扩展的并行计算平台上，设计并实现了冲击—接触的并行计算。算例证明，计算平台稳定可靠，算法简单实用，且具有较好的并行效率和可扩展性。