一种改进的H.264码率控制算法

码率控制是H.264视频编码中一项重要技术,对平稳码率和保证良好的图像质量起着重要作用.通过分析H.264 JVT-012中目标码率计算与分配算法的缺陷,提出了基于图像直方图和滑动窗技术的自适应改进方法.根据图像复杂度和场景切换,通过图像直方图和滑动窗引入比率因子λ,对预测的MAD进行自适应调整,使之更加接近真实的MAD值,从而有效地提高了码率控制的性能.实验结果表明,与JVT-G012算法相比,目标码率匹配更精确,图像解码质量提高且PSNR变化较小,并能较好地处理场景切换等问题.     

WCDMA HSPA向LTE的演进方案探讨

在WCDMA建网以HSPA为起点的情况下,向LTE/LTE＋的演进有两条路线。1）方案一：HSPA直接向LTE演进;该种方案演进过程过于激烈。2）方案二：通过HSPA＋过渡向LTE演进;其优势是演进平滑。本文从技术能力和实现难易角度,对WCDMA/HSPA到LTE的过渡方案和时机掌握,进行了探讨。     

Imp Raft: a consensus algorithm based on Raft and storage compression consensus for IoT scenario

In order to meet various challenges in the Internet of things (IoT), such as identity authentication, privacy preservation of distributed data and network security, the integration of blockchain and IoT became a new trend in recent years. As the key supporting technology of blockchain, the consensus algorithm is a hotspot of distributed system research. At present, the research direction of the consensus algorithm is mainly focused on improving throughput and reducing delay. However, when blockchain is applied to IoT scenario, the storage capacity of lightweight IoT devices is limited, and the normal operations of blockchain system cannot be guaranteed. To solve this problem, an improved version of Raft (Imp Raft) based on Raft and the storage compression consensus (SCC) algorithm is proposed, where initialization process and compression process are added into the flow of Raft. Moreover, the data validation process aims to ensure that blockchain data cannot be tampered with. It is obtained from experiments and analysis that the new proposed algorithm can effectively reduce the size of the blockchain and the storage burden of lightweight IoT devices.     

移动IPv6管理策略与仿真的研究

文章研究了移动IPv6管理策略问题。根据层次化移动IPv6路由和控制方法，通过仿真计算与分析．得出此局部频繁切换的移动IPv6控制方法能有效减少注册、绑定更新给网络性能带来的代价，使网络性能得到改善。     

一种基于H.264 Intra帧的错误隐藏算法

Intra帧图像对整个视频图像起着非常重要的作用.基于图像局部边缘类型和走向分析,提出一种能提高Intra帧图像质量的错误隐藏算法.首先根据相邻宏块中边缘类型和走向来判断当前出错宏块的边缘类型与走向分成多个小区域,以分块插值恢复数据.对平缓图像,采取时域替代方法恢复数据,既降低算法复杂度,又能保证良好的图像质量.实验结果表明,本算法能有效提高图像的解码质量.