Internet安全和防火墙技术:安全体系结构

根据防火墙技术的发展现状,分析了防火墙的功能需求,提出了五种防火墙的安全体系结构,对于防火墙设计和实现中的一些问题以及今后的发展方向提出了我们的看法。     

一种高吞吐率国密SM3硬件IP核的设计与实现

为满足网络安全认证的需求,提出了一种高吞吐率的国密SM3的硬件IP核的设计方法。该方法用3级流水线缩短了每轮运算的关键路径,提升了系统时钟,并将64轮运算全部展开,实现轮间64级流水线,总共192级的全流水线设计,能够同时实现192组消息的SM3运算。基于SMIC 0.18um的工艺,实现了该IP核,时钟频率达到了200MHz, 吞吐率达到了102.4Gbps,比现有的研究成果提升39.3%。     

Queuing monitoring system for a multi-mode shared-buffer for IBCN networks

The work presents system design and circuit architecture of a queuing monitoring system. The system has been designed for use mainly in our multi-mode shared-buffer for IBCN switches. Multiple queues use the shared-buffer and multiple functioning options are supported. In this way, there are increased demands for detailed queuing monitoring. The system totally monitors queue length per queue as well as a number of incoming dropped packets and a number of stored packets that push-out. It supports policies of serving connections with priority levels in buffer space terms. Its contribution is crucial because of the high complexity of multiple queue management. Its pilot circuit architecture can support wide range development of useful systems from multimedia terminal adapters to IBCN switches, or multiplexers, which can be used by research groups or manufacturers that develop IBCN products.     

一种基于卫星IP网络的数据链路层协议

通过分析卫星通信网络发展趋势,阐述卫星网络中现有的数据链路层协议,梳理归纳卫星网络的特点及影响,提出了一种新型卫星网络数据链路层协议(New Satellite Link Protocol,NSLP)。分析对比表明,该协议能够有效降低链路层报头开销,提高信息传输效率。在实际应用中,新型协议具有能够简化数据链路层的功能,有与TCP/IP协议兼容性好、与IP协议耦合度高、节约星上资源等诸多优点,有利于卫星IP网络整体性能的有效提升。     

Rapid Biofabrication of Printable Dense Collagen Bioinks of Tunable Properties

Recent convergence of the 3D printing of tissue‐like bioinks and regenerative medicine offers promise in the high‐throughput engineering of in vitro tissue models and organoids for drug screening and discovery research, and of potentially implantable neo‐tissues with tailored structural, biological, and mechanical properties. However, the current printing approaches are not compatible with collagen, the native scaffolding material. Herein, a unique biofabrication approach that uses automated gel aspiration‐ejection (GAE) is reported to potentially overcome these challenges. Automated‐GAE generates highly defined, aligned, dense collagen gel bioinks of various geometries (i.e., cylindrical, quadrangular, and tubular), dimensions, as well as tunable microstructural and mechanical properties that modulate seeded cellular responses. By densifying initial naturally derived reconstituted collagen hydrogels incorporating cells, automated‐GAE generates mini‐tissue building blocks with tailored protein fibril density and alignment, as well as cell loading, density and orientation according to the intended use. Surprisingly, a simple mathematical relationship defining the bioink compaction factor is found to be highly effective in predicting the initial and temporal properties of the bioinks in culture. Therefore, automated‐GAE will potentially also enable a fourth dimension to biofabrication, where cell–cell communications and cell‐extracellular matrix interactions as a function of time in culture can be predicted and modeled.     

用ASIC实现TCP数据流的重组和交付

随着网络带宽的迅速增加,当网络带宽达到吉比特时,如果TCP/IP协议的处理还在主CPU 中进行,由于CPU是通用芯片,处理协议的效率不高,这样不但占用了大量的CPU资源,而且不能充分的利用带宽资源。本文用ASIC实现了TCP数据流的重组和交付,其速度可达到3.2GB。     

Linux环境下基于TCP的Socket编程浅析

Socket适用于同一台计算机上的进程间通信，同时也适用于网络环境中的进程间通信。他已成为当前许多操作系统的网络API，也是网络操作系统中必不可少的基础功能。因特网为网络中的应用提供了2种类型的服务：由TCP协议提供的面向连接服务和由UDP协议提供的无连接服务。随着Linux操作系统的不断推广，Linux环境下的Socket开发和研究一直是人们关注的热点。文章介绍了Linux平台下的Socket及其在TCP协议下的编程原理，并通过一个用Java编写的基于TCP的客户／服务器程序，描述了网络中不同主机上的两个进程之间的Socket通信机制。     

双折射率色散效应对液晶可调光衰减器的影响

文章利用Jones矩阵方法计算和分析了双折射率色散效应对一种液晶可调光衰减器(VOA)衰减能力的影响.结果表明,当激光谱线宽度较窄时,双折射率色散效应将导致液晶VOA的光衰减能力大幅度减弱;反之,双折射率色散效应对液晶VOA光衰减能力的影响可以忽略,但液晶VOA本身的光衰减能力很低.因此,液晶VOA适用于较窄线宽的激光光源,在设计和使用时应充分考虑液晶双折射率色散效应对其光衰减能力的影响.     

基于中继协作的认知无线电性能研究

频谱感知是认知无线电技术的关键。协作频谱感知能够充分利用网络资源,提高网络中认知用户的检测概率,降低认知用户的虚警概率。基于两个认知用户之间的中继协作,研究了协作频谱感知的感知性能与吞吐量的折衷。仿真结果表明：中继协作的频谱感知方法能够使得在充分保证对授权用户不造成干扰即检测概率一定时,能够有效地降低认知用户感知授权用户的虚警概率,缩短＂弱＂认知用户获得最大吞吐量的最优感知时间,提高其最大吞吐量,并提高认知系统的最大吞吐量。     

基于IP多媒体子系统Diameter协议设计

Diameter协议用于IP多媒体子系统(IMS),实现认证、授权和计费功能。Diameter协议包含基础协议、传送协议和不同的应用扩展。介绍了Diameter在IMS中的接口关系,对Diameter协议进行了分析,提出了Diameter基础协议和Cx接口应用协议的软件设计流程,并介绍了最终实现的成果—能力交换、位置管理和用户数据处理。