利用运动向量差值改善深度学习视频隐写分析

目的 针对现有深度学习视频隐写分析网络准确率不够高的问题,本文从视频压缩编码的原理出发,发掘嵌密编码参数与其他参数之间的关系,通过拓展检测空间,构造新的检测通道,改善现有深度学习视频隐写分析网络的检测性能。方法 以H. 265/HEVC(high efficiency video coding)压缩视频为例,首先通过分析运动向量的嵌密修改对运动向量差值的影响,指出可将运动向量差值作为新增的采样对象(或称检测对象);接着,提出一个构造运动向量差值检测矩阵的方法,解决了空域上采样样本稀疏、时域上样本空间位置无法对齐的问题;最后,将运动向量差值矩阵直接用于改善现有的VSRNet(video steganalysis residual network)、SCA-VSRNet(selection-channel-aware VSRNet)以及Q-VSRNet(quantitative VSRNet)等3个H. 265/HEVC深度学习视频隐写分析网络,分别得到IVSRNet(improved VSRNet)、SCA-IVSRNet(selection-channel-aware improved...     

Extended Process to Product Modeling (xPPM) for integrated and seamless IDM and MVD development

This paper proposes a new extended Process to Product Modeling (xPPM) method for integrated and seamless information delivery manual (IDM) and model view definition (MVD) development. Current IDM development typically uses Business Process Modeling Notation (BPMN) to represent a process map (PM). Exchange requirements (ERs) and functional parts (FPs) specify the information required when information is exchanged between different activities. A set of information requirements, specifically defined as a subset of Industry Foundation Classes (IFC), is called an MVD. Currently however, PMs, ERs, FPs, and MVDs are developed as separate documents through independent development steps. Moreover, even though ERs and FPs are designed to be reused, tracking and reusing the ERs and FPs developed by others is practically impossible. The xPPM method is proposed to provide a tight connection between PMs, ERs, FPs, and MVDs and to improve the reusability of predefined ERs and FPs. The theoretical framework is based on the approach of the Georgia Tech Process to Product Modeling (GTPPM) to suit the IDM development process. An xPPM tool is developed, and the validity of xPPM is analyzed through the reproduction of existing IDMs and MVDs. The benefits and limitations of xPPM and lessons from the applicability tests are discussed.     

关系数据库中嵌入型多值依赖的成员问题

对于函数依赖、多值依赖都建立了正确(sound)、完备的(complete)公理系统.对于嵌入型多值依赖的正确、完备的公理系统问题,Sagir、Walacka 已证明它没有有限公理系.但嵌入型多值依赖作为特殊情况包含的型板依赖被定义之后,它的成员问题已有半判定方法.特别是对嵌入型多值依赖集合作一些限制后,它的成员问题可解性已被提出.本文对 Chase过程作了更改后,形成 N-Chase 过程,并利用它对一种嵌入型多值依赖集证明了其成员问题的可解性.     

高压变频在600MW火电厂10kV凝结泵上的应用

本文介绍了级联多单元高压变频调速装置在600MW空冷发电机组凝结水泵节能改造中的应用，简述了装置的工作原理和“一拖二”连接方法，并进行了节能经济分析。     

Adaptive depth truncation filter for MVC based compressed depth image

In multiview video plus depth (MVD) format, virtual views are generated from decoded texture videos with corresponding decoded depth images through depth image based rendering (DIBR). 3DV-ATM is a reference model for the H.264/AVC based multiview video coding (MVC) and aims at achieving high coding efficiency for 3D video in MVD format. Depth images are first downsampled then coded by 3DV-ATM. However, sharp object boundary characteristic of depth images does not well match with the transform coding based nature of H.264/AVC in 3DV-ATM. Depth boundaries are often blurred with ringing artifacts in the decoded depth images that result in noticeable artifacts in synthesized virtual views. This paper presents a low complexity adaptive depth truncation filter to recover the sharp object boundaries of the depth images using adaptive block repositioning and expansion for increasing the depth values refinement accuracy. This new approach is very efficient and can avoid false depth boundary refinement when block boundaries lie around the depth edge regions and ensure sufficient information within the processing block for depth layers classification. Experimental results demonstrate that the sharp depth edges can be recovered using the proposed filter and boundary artifacts in the synthesized views can be removed. The proposed method can provide improvement up to 3.25 dB in the depth map enhancement and bitrate reduction of 3.06% in the synthesized views.     

用于多视视频加深度的错误隐藏算法

提出了一种针对多视视频加深度(MVD)的错误隐藏( EC)算法。算法充分利用MVD特有的深度 信息及当前丢失宏块周围正确解码的宏块信息,将丢失宏块分为3类不同属性的宏块。针对3类宏块的特 点,分别提出了基于候选运动矢量修正(CMVR)、基于深度的外边界匹配(DOBMA)以及自适应 权 值的EC(AWEC)等模式。实验表明,本文提出的算法在保证相同的视频主客观质量情况下, 能够快速有效地实现EC。     

Sum-of-gradient based fast intra coding in 3D-HEVC for depth map sequence (SOG-FDIC)

As the latest video coding standard for multi-view plus depth video, 3D-HEVC yields high coding efficiency but at the cost of heavy computational complexity. To reduce the computational complexity, a fast intra coding algorithm based on sum-of-gradient criterion for depth map coding in 3D-HEVC, named SOG-FDIC, is proposed in this paper. Based on the observation that DMM modes and smaller partitioning sizes are rarely used in flat region, sum of gradient is presented to determine whether the current block belongs to the flat region so as to skip unnecessary checking of DMMs and smaller partitioning sizes. Experimental results show that the proposed algorithm can save about 21.8% coding time while keeping almost the same coding efficiency and the reconstructed video quality of depth maps and synthesized views, compared with the original 3D-HEVC. Moreover, it has been verified that the proposed method outperforms the state-of-the-art methods.     

An analysis of decomposition approaches in multi-objectivization via segmentation

Multi-objectivization via Segmentation (MOS) has been shown to give improved results over other previous multi-objectivization approaches. This paper explores the mechanisms that make different segmentations in MOS successful in the context of the Traveling Salesman Problem (TSP). A variety of new segmentation methods are analyzed and theories regarding their performance are presented. Spatial segmentation methods are compared with other adaptive and static decomposition methods. Insight into why previous adaptive methods performed well is provided. New decomposition methods are proposed and several of these methods are shown to attain better performance than previously known methods of decomposition. The convergence of various degrees of multi-objectivization is examined leading to a new, more general segmentation algorithm, Multi-Objectivization via Progressive Segmentation (MOPS). MOPS combines the single-objective genetic algorithm with multi-objectivization in a general form. In a given run MOPS can progress from a more traditional single objective method to a strong multi-objectivization method. MOPS attempts to improve the ratio of fitness improvements to fitness decrements, signal-to-noise ratio (SNR), over the course of an evolutionary optimization based on the principle that often fitness improvements are generally easier to find early in the run rather than late in the run. It is shown that MOPS provides robust performance across a variety of problem instances and different computational budgets.     

存在多值依赖(MVD)的XML文档的规范化

讨论了在XML文档中存在多值依赖的情况下，如何规范XML文档，从而使XML文档有更小的冗余，以及更新、删除、插入异常。并在此基础上提出了一个规范化算法，来规范存在多值依赖的XML文档。并给出了算法的说明。     

基于混合七电平电压型逆变器的新型6kV变频器

提出了一种基于混合七电平电压型逆变器的6kV变频器。混合七电平逆变器由1个采用10CT的三相中点箝位三电平逆变器和3个采用IGBT的H桥逆变器串联而成，可充分利用IGCT高压大容量及IGBT高速的特点。PWM控制采用基于参考电压分解的多电平直接PWM算法。数字化实现容易。采用了改进的死区效应补偿方法以获得理想的输出波形。研制了1台基于混合七电平逆变器的交流380V变频调速实验样机。实验结果为新型6kV变频器工业装置的研制打下了基础。