面向乳腺超声计算机辅助诊断的两阶段深度迁移学习

目的 为了提升基于单模态B型超声（B超）的乳腺癌计算机辅助诊断（computer-aided diagnosis,CAD）模型性能,提出一种基于两阶段深度迁移学习（two-stage deep transfer learning,TSDTL）的乳腺超声CAD算法,将超声弹性图像中的有效信息迁移至基于B超的乳腺癌CAD模型之中,进一步提升该CAD模型的性能。方法 在第1阶段的深度迁移学习中,提出将双模态超声图像重建任务作为一种自监督学习任务,训练一个关联多模态深度卷积神经网络模型,实现B超图像和超声弹性图像之间的信息交互迁移;在第2阶段的深度迁移学习中,基于隐式的特权信息学习（learning using privilaged information,LUPI）范式,进行基于双模态超声图像的乳腺肿瘤分类任务,通过标签信息引导下的分类进一步加强两个模态之间的特征融合与信息交互;采用单模态B超数据对所对应通道的分类网络进行微调,实现最终的乳腺癌B超图像分类模型。结果 实验在一个乳腺肿瘤双模超声数据集上进行算法性能验证。实验结果表明,通过迁移超声弹性图像的信息,TSDTL在基于B超的乳腺癌诊断任务中取得的平均分类准确率为87.84±2.08%、平均敏感度为88.89±3.70%、平均特异度为86.71±2.21%、平均约登指数为75.60±4.07%,优于直接基于单模态B超训练的分类模型以及多种典型迁移学习算法。结论 提出的TSDTL算法通过两阶段的深度迁移学习,将超声弹性图像的信息有效迁移至基于B超的乳腺癌CAD模型,提升了模型的诊断性能,具备潜在的应用可行性。     

Long-haul secure data transfer using hardware-assisted GridFTP

Extreme-scale scientific collaborations require high-performance wide-area end-to-end data transports to enable fast and secure transfer of high data volumes among collaborating institutions. GridFTP is the de facto protocol for large-scale data transfer in science environments. Existing predominant network transport protocols such as TCP have serious limitations that consume significant CPU power and prevent GridFTP from achieving high throughput on long-haul networks with high latency and potential packet loss, reordering and jitter. On the other hand, protocols such as UDT that address some of the TCP shortcomings demand high computing resources on data transfer nodes. These limitations have caused underutilization of existing high-bandwidth links in scientific and collaborative grids. To address this situation, we have enhanced Globus GridFTP, the most widely used GridFTP implementation, by developing transport offload engines such as UDT and iWARP on SmartNIC, a programmable 10GbE network interface card (NIC). Our results show significant reduction in server utilization and full line-rate sustained bandwidth in high-latency networks, as measured for up to 100 ms of network latency. In our work, we also offload OpenSSL on SmartNIC to reduce host utilization for secure file transfers. The offload engine can provide line-rate data channel encryption/decryption on top of UDT offload without consuming additional host CPU resources. Lower CPU utilization leads to increased server capacity, which allows data transfer nodes to support higher network and data-processing rates. Alternatively, smaller or fewer DTNs can be used for a particular data rate requirement.     

一种安全协议的安全性分析及攻击研究

针对Web安全协议SSL的握手协议部分进行了详尽的阐述，对其安全性作了一定的分析，给出了理论上存在的三个协议漏洞的详尽描述，并且经过测试验证，指出了SSL协议存在***模式漏洞。     

An empirical study on improving dissimilarity-based classifications using one-shot similarity measure

This paper reports an experimental result obtained by additionally using unlabeled data together with labeled ones to improve the classification accuracy of dissimilarity-based methods, namely, dissimilarity-based classifications (DBC) [25]. In DBC, classifiers among classes are not based on the feature measurements of individual objects, but on a suitable dissimilarity measure among the objects instead. In order to measure the dissimilarity distance between pairwise objects, an approach using the one-shot similarity (OSS) [30] measuring technique instead of the Euclidean distance is investigated in this paper. In DBC using OSS, the unlabeled set can be used to extend the set of prototypes as well as to compute the OSS distance. The experimental results, obtained with artificial and real-life benchmark datasets, demonstrate that designing the classifiers in the OSS dissimilarity matrices instead of expanding the set of prototypes can further improve the classification accuracy in comparison with the traditional Euclidean approach. Moreover, the results demonstrate that the proposed setting does not work with non-Euclidean data.     

SSL协议及WEB安全实现

SSL是一种安全传输协议,其全称是Securesocketlayer(安全套接层)。该协议最初由Netscape企业发展而来,现已成为网络上用来鉴别网站和网页浏览者身份,以及在浏览器使用者及网页服务器之间进行加密通讯的全球化标准。本文主要从SSL协议的原理和主要应用进行介绍。     

SSL VPN技术在高校图书馆中的应用研究

简单介绍了VPN原理和技术.通过分析OpenVPN的技术特点,结合高校图书馆的实际需要,详细阐述如何在Linux环境中利用OpenVPN技术构建远程安全访问SSL VPN服务器,实现校外用户远程访问图书馆信息资源.     

煤炭网电子支付中SSL协议的改进与实现

随着电子商务的普及,煤炭业也有了自己的电子商务网站,煤炭网的安全协议SSL存在不安全性,文中提出了对SSL协议的改进方案,并给出了双重签名的认证原理与系统的模拟实现。     

Secure Socket Layer协议在电子政务系统安全建设中的应用

针对目前日益突出的电子政务安全问题，在Secure Socket Layer协议的基础上，对我国电子政务的安全问题进行探讨，并针对目前政府机构信息化建设中的数据安全传输问题提出几点改进工作方案。     

基于SSL VPN的系统备用通道设计与实现

东莞供电局是特大型供电企业,年供电量达到600亿千瓦时,该局城域网处于光纤传输单链路运行状态,未建设备用通道,为保证城域网承栽的OA、营销等重要系统的稳定性和连续可用性,建立基于SSL VPN的系统备用通道,以应对城域网光纤链路可能出现的异常情况.该系统于2007年10月份开始实施,目前运行良好,并在几次局部的光纤故障中保证主要业务系统不中断起到关系的作用.     

基于Java2的身份认证数字签名和SSL实现技术

本文介绍了如何利用Java2平台提供的资源实现身份认证和数字签名。