洞察高级持久性威胁

正高级持久性威胁(APT)的发起者利用多种意想不到、时间敏感而且各不相同的攻击向量来攻击你的服务器。在尝试识别、抵御和防止此类攻击威胁时,我们的经验、知识和技术可帮助您做出有效的安全干预决策。如果缺乏对环境、实际网络流量及内容的全面了解,您只能凭空猜测,因此最终的决策可能对,也可能不对。出现APT安全问题时,企业通常会向网络安全运行专业人员施加压力,要求他们快速解释并解决问     

中国网站用户体验排行榜

网站运营商提高网站用户体验满意度的九条黄金定律中的第五条是：需重点关注网站非功能性部分的设计标准。 在网站的发展进程中,大部分网站把注意力放在了新的附加功能应用方面。例如：一些网站充斥了Flash元素,甚至全部采用Flash来实现页面显示和功能应用。     

A quantitative multimodal discourse analysis of teaching and learning in a web-conferencing environment – The efficacy of student-centred learning designs

This paper presents a quantitative approach to multimodal discourse analysis for analyzing online collaborative learning. The coding framework draws together the fields of systemic functional linguistics and Activity Theory to analyze interactions between collaborative-, content- and technology-related discourse. The approach is used to examine how the task subject matter, the activity design, and the choice of interface affected interaction and collaboration for a computing course conducted in a web-conferencing environment. The analysis revealed the critical impact of activity design on the amount and type of discourse that transpired. Student-centred designs resulted in over six times more student discourse as compared to teacher-centred designs and created a learning environment where students took greater ownership over the tasks and contributed more to the content-based discussion. The paper also incorporates a rationale for the approach to coding and a reflection on its efficacy for discourse analysis in technology-based learning environments.     

基于调频连续波信号的圆弧式合成孔径雷达成像方法

圆弧式合成孔径雷达是一种对特定地区持续监测的新模式雷达, 具有分辨率高, 观测范围广, 重访周期短等特点, 适合对特定地区的形变监测以及对塌方、滑坡等灾害的预警。针对圆弧式合成孔径雷达特殊的运动形式, 该文提出了一种新的用于调频连续波体制Arc-SAR成像的2维频域算法。首先推导了Arc-SAR的信号模型, 然后提出了在满足转动机械臂长远小于目标最短斜距的情况下使用2维频域算法来聚焦信号, 之后分析了算法误差。该算法可以在假设条件下对目标准确聚焦, 并具有计算速度快等优点。最后使用仿真和实测数据验证了算法的有效性。      

Very Low Degree of Energetic Disorder as the Origin of High Mobility in an n‐channel Polymer Semiconductor

Charge transport is investigated in high‐mobility n‐channel organic field‐effect transistors (OFETs) based on poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (P(NDI2OD‐T2), Polyera ActivInk? N2200) with variable‐temperature electrical measurements and charge‐modulation spectroscopy. Results indicate an unusually uniform energetic landscape of sites for charge‐carrier transport along the channel of the transistor as the main reason for the observed high‐electron mobility. Consistent with a lateral field‐independent transport at temperatures down to 10 K, the reorganization energy is proposed to play an important role in determining the activation energy for the mobility. Quantum chemical calculations, which show an efficient electronic coupling between adjacent units and a reorganization energy of a few hundred meV, are consistent with these findings.     

用于130nm/90nm新工艺开发的铜CMP阻挡层磨料系统(英文)

通过与实验室的CMP和集成工程师合作,采用测试系统观察两种或两种以上混合配方磨料的选择比。实验数据表明,通过改变单个化学试剂组分的浓度改变磨料的选择比效果突出,磨料配方师可以简便地修改磨料配方。这种方法的优点是,如果改变集成方法或特殊膜层,可以很快地重新优化磨料。如SiN膜取代TEOW淀积氧化物膜,对新系统可以容易地重新优化磨料。介绍了几种磨料组分浓度的去除速率和选择比。     

透视Virtex-4超高效且低功耗的奥秘

随着工艺技术越来越小型化、越来越快速,通常会增加功耗,这时在功耗和效能上往往必须有所取舍,因而器件功耗一直是半导体业的首要课题。来自Xilinx的新型Virtex-4FPGA采用创新的架构特性和先进的IC设计技术,可以在显著降低功耗的同时,依然不损害其性能,且和90nm工艺技术特征尺寸减小的趋势不谋而合。本文将探讨XilinxIC设计者如何在高性能Virtex-4FPGA中实现很高的功率效率。