基于广义Feistel结构的分组图像加密算法

为了提高加密信息的安全性等要求,提出了一种广义拟feistel结构分组加密算法。首先利用三角混沌映射产生混沌序列并将明文分块,然后将三角混沌映射和灰度扩散机制相结合依次对明文进行替换,最后将三角混沌作为密钥用于广义拟feistel结构分组加密算法对替换后的明文加密。通过对加密后图像相邻像素所对应的共生矩阵特性分析表明,加密图像具有良好的空间随机均匀分布特性。     

图像分割的自适应K均值聚类算法研究

使用K均值聚类算法完成对图像的分割是一种常见的分割技术,针对传统的K均值聚类算法的不足,提出了使用直方图波形的有效波峰个数自适应确定K值的大小,实验结果表明,该方法简单、灵活、容易实现,并能取得较好的结果。     

在线教师专业发展新理路：英国“学习设计支持环境项目”的探索与启示*

在线合作与反思成为教师专业发展的重要途径,具有显著的生态性效应、经济性和可持续性优势。英国伦敦大学教育学院承担的学习设计支持环境项目是对在线教师专业发展的一次成功探索,取得了良好的社会效益。作者概括了该项目的研究背景,整理了其探索内容和路径,分析了其理念以及对我国在线教师专业发展研究和实践的意义和启示。     

Understanding the relative contribution of technical and tactical performance to match outcome in Australian Football

ABSTRACT

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009–2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.     

Image Repair on the Donald Trump “Access Hollywood” Video: “Grab Them by the P*ssy”

In October 2016, Donald Trump was in the midst of a hotly contested and sharply divisive presidential campaign. Days before the second presidential debate, The Washington Post posted a video of Trump “having extremely lewd conversation about women in 2005.” This video and the firestorm of criticism it provoked threatened to derail his presidential run. Mr. Trump and his wife Melania Trump offered several messages to repair his damaged image. This article analyzes and evaluates these image repair messages concerning Donald Trump’s “Access Hollywood” video. In such a divisive context, the defense had no hope of repairing Trump’s image with the general public (Trump lost the popular vote by 2.9 million). Even though he lost the popular vote, the business magnate won the Electoral College. We cannot say that the “Access Hollywood” video was solely responsible for Trump’s poor popular vote showing, but it is clear that this defense did not completely dispel the cloud surrounding him.     

2D-WHT在实时图象处理中的应用

简述2D－WHT的快速算法，提出了基于此算法的实时图象降噪系统；给出了系统的结构框图，软件模拟结果及其物理意义的诠释；最后给出硬件设计框图以及系统应用范围．     

基于照片的抽象线条画生成

绘画作品以其鲜明的表达方式常常能给观众留下深刻的印象。但其对创作者的高要求使普通大众难以得心应手的自己进行创作。随着科学技术的发展,基于数码照片对各种绘画风格进行模拟成为了非真实感图形学研究的热点。本文在总结前人研究成果的基础上,结合尺度空间理论和边缘检测技术,提出了一种基于照片生成抽象线条画的方法。通过实验证明,本方法能较好的模拟线条画的主要特点。     

论网络教育精品课程建设的若干关键问题

当前网络教育精品课程建设的关键问题有:课程教师难以全身心投入网络教学;网络课件不符合学生自主学习需要;网络教学缺乏过程性;学习支持服务不规范。针对上述问题提出了以下对策措施:建立一支专兼结合、分工明确的教师队伍;设计适合学生自主学习的网络课件;积极开展网络教学活动;通过制度建设改进学习支持服务的规范性;积极争取学校的政策支持。     

高校信息化教学环境的建设与探索——以西北工业大学为例

信息化教学环境是高校数字校园的重要组成部分。文章结合西北工业大学的建设实践,阐述了信息化教学环境的建设思路和方案;重点分析了教学活动支撑、资源制作与管理、网络学习支持和实时教学评估四个平台的系统组成;介绍了学校建设情况和实践效果;最后提出了运行管理中应注意的几个问题。