视频内容安全保障新方法探索与实践——视频基因管控系统

在网络安全形势日趋严峻的今天,互联网视频网站、广播电视网络等视频播出系统遭受网络攻击已经成为现实.提出了一种可在传输线路上实时保障视频内容安全的新方法——视频基因管控系统,可部署在播出系统出口线路上,作为独立、隐形的视频内容安检闸门,确保广电前端网络或互联网视频网站被恶意攻击并控制时,违规内容仍无法输出到网络上.系统还可部署在承载网的传输线路上,为多屏融合情形下的碎片化视频内容监管、内容版权保护提供基于传输线路的实时解决方法.     

一种网络视频行业应用解决方案

近几年对网络视频行业应用解决方案的研究主要集中在视频监控行业和酒店行业,只解决了行业应用中的一部分模式类型,还有更多的行业需求没有被满足.结合IPTV与高校视频应用合作的案例,提出一种开放化的IPTV架构,满足自有内容与版权内容混合服务行业应用模式,不仅为高校师生提供有版权的优质视频内容,还可为高校自身丰富的视频资源,包括活动、讲座、校园电视台等内容,提供发布的渠道和服务的平台.     

利用浮标和NWP风场对HY-2散射计联合定标验证

本文对海洋二号卫星微波散射计(Haiyang-2 Scatterometer,HY-2 SCAT)进行了海洋定标算法研究,并使用数值天气预报模型风场(Numerical Weather Prediction,NWP)和浮标数据对定标后反演风场进行联合验证.通过匹配2012年12月份的HY-2 SCAT反演风场、NWP风场及浮标的观测数据,共得到无降雨条件下的3112个25km分辨率的匹配数据.对匹配数据进行分析时,采用基于变量的误差分析方法能够得到比传统线性回归方法更精确的验证结果.选取在风场U、V分量进行联合验证能得到较在风速、风向上更为有利的验证结果.验证结果表明,经过海洋定标法之后的HY-2 SCAT测量后向散射系数的误差残余小于0.15dB,其反演风场与浮标及NWP数据相吻合,U、V分量相对浮标及NWP数据偏差均小于0.23m/s,验证了该定标算法的有效性及定标后反演风场的高精度.     

基于GF-1数据的三峡库区水体信息精细化提取

为实现江河类狭长型水体信息的精细化提取，利用GF-1卫星数据，采用支持向量机和目视解译相结合的方法对三峡库区及重庆市水体信息进行了精细化提取。使用总体分类精度、Kappa系数、错分误差、漏分误差、制图精度和用户精度等指标对库区水体信息粗提取结果进行验证分析。结果表明:4个试验区水体提取的总体分类精度均超过90%，除试验区4的Kappa系数为0.884 1以外，其余试验区均超过0.9，提取精度较高。结合目视解译的方法，在粗提取结果的基础上对各问题进行精细化处理，得到精度高、完整性好的三峡库区以及重庆市水体信息数据，可为后续该区域的精细化遥感业务开展提供有效资料。     

基于GsMAP的尼洋河流域降水时空分布特征研究

鉴于尼洋河地区实测降雨资料缺乏,卫星降雨产品具有显著优势,基于GsMAP降雨产品数据和地面观测站点数据,利用降雨量年内分配特征的δ方法建立卫星降雨校正公式,分析流域降雨量的时空分布特征。结果表明,实测站点月降雨量校正结果较好,相关系数达0.954,年尺度的站点降雨相关系数为0.54,降雨量空间分布呈现出自西向东递增的特点。卫星降雨观测在西部地区存在低估,东部地区有一定程度的高估,在降雨梯度分布上,流域在3500~4000m高程段降雨量呈上升趋势,其他高程段均为显著下降,整体变化率为-104mm/km。流域的年均面平均降雨量为699mm,降雨多集中于夏季,且有逐年增加趋势。     

Controllable Image‐Based Transfer of Flow Phenomena

Modelling flow phenomena and their related weathering effects is often cumbersome due their dependence on the environment, materials and geometric properties of objects in the scene. Example‐based modelling provides many advantages for reproducing real textures, but little effort has been devoted to reproducing and transferring complex phenomena. In order to produce realistic flow effects, it is possible to take advantage of the widespread availability of flow images on the Internet, which can be used to gather key information about the flow. In this paper, we present a technique that allows the transfer of flow phenomena between photographs, adapting the flow to the target image and giving the user flexibility and control through specifically tailored parameters. This is done through two types of control curves: a fitted theoretical curve to control the mass of deposited material, and an extended colour map for properly adapting to the target appearance. In addition, our method filters and warps the input flow in order to account for the geometric details of the target surface. This leads to a fast and intuitive approach to easily transfer phenomena between images, providing a set of simple and intuitive parameters to control the process.     

Modeling and analysis for multilayered complex communication network of satellite navigation system

This study is extended to construct the network model, the node model, and the link model of complex communication network for satellite navigation system (CCN‐SNS) based on the hierarchical architecture. Firstly, a method called snapshots was proposed to describe the dynamic topology for CCN‐SNS; secondly, another method was put forward to model the different nodes of the CCN‐SNS; thirdly, the different links between every two different nodes were modeled. Therefore, based on the OPNET tools, a simulation for the CCN‐SNS, which contains the models that proposed earlier used to analyze the navigation accuracy and network transmission performance, was performed.     

Making friends in online games: gender differences and designing for greater social connectedness

ABSTRACT

While online multiplayer games provide an opportunity for players to both maintain and establish new connections, male and female players have been found to experience these environments differently. Interviews (n?=?22) and focus groups (n?=?14) were used to explore these differences as they impact on creating new social connections, as well as to provide recommendations for the development of new social tools and features that account for these differences. While all participants experienced toxicity and performance pressure as barriers to forming new connections, female players uniquely reported the impacts of misogynistic targeting and stereotype threat. In turn, female players wishing to avoid these stresses would often mask their gender. The common practice of gender misrepresentation by both male and female players impacted female players’ ability to create social connections through voice technology, as well as building their distrust of unknown others. Recommendations are made to build social connectedness between players taking into account the specific constraints faced by female players. These include establishing mentoring opportunities as well as profiling players beyond their immediate skill or rank. Additionally, the desire for control of one’s online identity presents practical challenges that may be overcome through thoughtful design.     

基于变分正则化的低质视频图像二维增强仿真

受环境、硬件设备及成本等因素限制,所生产的视频质量低,存在大量冗余噪声,导致局部区域图像模糊不清,无法对目标个体判定或识别。为解决上述问题,构建一种基于变分正则化的低质视频图像二维增强方法。通过采集先验信息,确定噪声去除和质量增强区域,随后使用ROF经典模型和偏微分对原始图像做平滑及去噪处理,并提出前后扩散方程,使方法能够有效抑制背景区域噪声,并对目标个体边缘做锐化处理,利用变分正则化提升视频图像整体分辨率,使其完成图像二维增强。仿真结果表明,所提方法具有控制噪声与加强图像质量双重优势,有效去除、抑制噪声影响,提升目标个体区域强散射点,且方法复杂程度较低,能够实现低质视频图像的均衡优化。     

Progressive Refinement Imaging

This paper presents a novel technique for progressive online integration of uncalibrated image sequences with substantial geometric and/or photometric discrepancies into a single, geometrically and photometrically consistent image. Our approach can handle large sets of images, acquired from a nearly planar or infinitely distant scene at different resolutions in object domain and under variable local or global illumination conditions. It allows for efficient user guidance as its progressive nature provides a valid and consistent reconstruction at any moment during the online refinement process. Our approach avoids global optimization techniques, as commonly used in the field of image refinement, and progressively incorporates new imagery into a dynamically extendable and memory-efficient Laplacian pyramid. Our image registration process includes a coarse homography and a local refinement stage using optical flow. Photometric consistency is achieved by retaining the photometric intensities given in a reference image, while it is being refined. Globally blurred imagery and local geometric inconsistencies due to, e.g. motion are detected and removed prior to image fusion. We demonstrate the quality and robustness of our approach using several image and video sequences, including handheld acquisition with mobile phones and zooming sequences with consumer cameras.