Systematic lossy error protection based on H.264/AVC redundant slices and flexible macroblock ordering

INTRODUCTION In typical video transmission systems, a video signal is compressed, and the resulting bit stream is transmitted over an error-prone channel. The errors may consist of symbol errors caused by fading, as observed for wireless channels, or packet erasures caused by congestion, as observed in the Internet. If a received video packet contains errors, then the portion of the video signal contained in the packet is lost and must be concealed. Error concealment schemes alone cannot …     

图书订购和现场采购模式的对比分析

就图书订购和现场采购两种模式进行对比分析,认为二种模式各有优势和局限,现场采购的优势能弥补订购模式带来的不足,而订购模式的长处又能有效弥补现场采购的缺陷,它们相互依存,又相互补充,只有合理地选择和运用,才能更好地完成图书采购工作。     

Adaptive early termination of fast mode decision in MVC based on inter-view correlation

Variable size motion estimation (ME) and disparity estimation (DE) are employed to select the best coding mode for each macroblock (MB) in the current joint multiview video model (JMVM).This technique achieves the highest possible coding efficiency,but it results in extremely large computation complexity which obstructs the multiview video coding (MVC) from practical application.This paper proposes an adaptive early termination of fast mode decision algorithm for MVC.It makes use of the coding information o...     

动态演示排序过程课件的设计与实现

本介绍一种多媒体辅助教学程序,即利用VFP（Visual Foxpro)的添加新属性和新方法、动态地演示排序过程,并以快速排序为例编写其程序。     

Rate Control for MPEG-4 Bit Stream

Totransmitthemultimediadataovertheinternet ,pre encodedvideobitstreamsarepreferablebecauseofthelimitofthenetworkbandwidth .Inmostcases ,theencodershouldknowthechannelcharacteristicsinad vanceandencodethemasparameters .Consequently ,theflexibilityisreduced .Theratecontrolisemployedtocontroltheoutputbitrateaccordingtonetworkcondi tions.Forwirelessnetworks ,theirbandwidthsaremuchmorelimitedthanwirenetworks.Soratecontrolbecomesespeciallyimportantfortransmittingmultimediaoverthewirelessdomains[1- …     

新型的近仙农理论极限码:之型码和级联之型码

This paper introduces a family of error-correcting codes called zigzag codes.A zigzag code is described by a highly structured zigzag graph.Due to the structureal properties of the graph,very low-complexity soft-in,soft-out decoding rules can be implemented.we present a decoding rule,absed on the Max-Log-APP(MLA) formulation,which requires a total of only 20 addition-equivalent-operations per information bit per iteration.Simulation of a rate-1/2 concatenated zigzag code with four constitutent encoders with interlezer length 65536 yields a bit error rate(BER) and of 10^-5 at 0.9 dB and 1.4dB away from the Shannon limit by optimal (APP) and low-cost sub-optimal(MLA) decoders,respectively.     

Perceptual importance analysis for H.264/AVC bit allocation

The existing H.264/AVC rate control schemes rarely include the perceptual considerations. As a result, the improvements in visual quality are hardly comparable to those in peak signal-to-noise ratio （PSNR）. In this paper, we propose a perceptual importance analysis scheme to accurately abstract the spatial and temporal perceptual characteristics of video contents. Then we perform bit allocation at macroblock （MB） level by adopting a perceptual mode decision scheme, which adaptively updates the Lagrangian multiplier for mode decision according to the perceptual importance of each MB. Simulation results show that the proposed scheme can efficiently reduce bit rates without visual quality degradation.     

H.264/AVC视频容错传输的菱形FMO分布方法

图像压缩技术是基于在空域,时域或者频域上移除数据冗余的算法。它相当大地减少了数据转换率,但是随之的视频压缩信号对于传输误差更加敏感。差错恢复技术相对于通道误差增强了视频比特流的鲁棒性。在H.264/AVC的条带编码作为一种差错恢复技术之一被用于限制接收视频品质的数据丢失效应。有一种模式非常重要,它是将图像的宏块分配成不同的条带组,并能够提供不同的差错恢复标准。该文将深入分析这一类分散类型的灵活的宏块顺序(FMO)模式性能,并提出一个定义明确的系统模式,可以更完全地挖掘宏块顺序中离差概念从而克服误差损失。仿真结果显示:新的改进方案的性能优于传统模式。     

Temporal Error Concealment Technique for MPEG-4 Video Streams

Concerning inter4v mode employed widely in MPEG-4 video, a new temporal error concealment scheme for MPEG-4 video sequences is proposed, which can selectively interpolate one or four motion vectors (MVs) for the missing macroblock (MB) according to the estimated MB coding mode. Performance of the proposed scheme is compared with the existing schemes with multiple testing sequences at different bit error rates. Experimental results show that the proposed algorithm can mask the impairments caused by transmission errors more efficiently than 0 MV and average MV methods by consuming more time for different bit error rates. It has an acceptable image quality close to that obtained by the selective motion vector matching (SMVM) algorithm, while taking less than half of cycles of operations. The proposed concealment scheme is suitable for low complexity video real-time implementations.     

Efficient VLSI architecture of CAVLC decoder with power optimized

This paper presents an efficient VLSI architecture of the contest-based adaptive variable length code (CAVLC) decoder with power optimized for the H.264/advanced video coding (AVC) standard. In the proposed design, according to the regularity of the codewords, the first one detector is used to solve the low efficiency and high power dissipation problem within the traditional method of table-searching. Considering the relevance of the data used in the process of runbefore’s decoding, arithmetic operation is combined with finite state machine (FSM), which achieves higher decoding efficiency. According to the CAVLC decoding flow, clock gating is employed in the module level and the register level respectively, which reduces 43% of the overall dynamic power dissipation. The proposed design can decode every syntax element in one clock cycle. When the proposed design is synthesized at the clock constraint of 100 MHz, the synthesis result shows that the design costs 11 300 gates under a 0.25 μm CMOS technology, which meets the demand of real time decoding in the H.264/AVC standard.     

Neural decoding based on probabilistic neural network

Brain-machine interface (BMI) has been developed due to its possibility to cure severe body paralysis. This technology has been used to realize the direct control of prosthetic devices,such as robot arms,computer cursors,and paralyzed muscles. A variety of neural decoding algorithms have been designed to explore relationships between neural activities and movements of the limbs. In this paper,two novel neural decoding methods based on probabilistic neural network (PNN) in rats were introduced,the PNN decode...     

The role of numerical and non-numerical ordering abilities in mathematics and reading in middle childhood

This study investigated whether different types of ordering skills were related to mathematics achievement in children (n = 100) in middle childhood, after the effects of age, socio-economic status, IQ, and processing speed were taken into account. The relations between ordering skills and magnitude processing were also investigated, as well as the possibility that some of the shared variance between math and reading is explained by ordering abilities. The ordering tasks included the ordering of familiar numerical and non-numerical sequences, a parental report of children’s everyday ordering skills, and an order working memory task. Three magnitude processing tasks (symbolic and non-symbolic comparison and number line estimation), were also administered, as well as measures of inhibition and spatial working memory. From this set of measures, number ordering, order working memory and number line estimation emerged as the most important predictors of mathematics skills. We found that number ordering mediated the effect of both symbolic and non-symbolic comparison skills on mathematics, further confirming that this task captures some essential skills related to mathematics. Additionally, order working memory mediated the effect of both number comparison and reading skills on math. Finally, whereas non-symbolic comparison and number line estimation are considered important indicators of magnitude processing skills, there was no relationship between these abilities, but there was a correlation between each of these abilities and reading skills, with number line estimation also mediating the effect of reading skills on math. These novel findings could contribute to a better understanding of the basic processes underlying math ability, and why math and reading are strongly related in typical populations and in children with learning difficulties.     

Historicizing tianrenheyi as correlative cosmology for rethinking education in modern China and beyond

Abstract

The Chinese tianrenheyi thesis bespeaks a correlative cosmology irreducible to the Western metaphysics. This article historicizes tianrenheyi for new implications to help rethink the given concepts of ‘person/thing,’ ‘environment/nature,’ and ‘relationality’ in contemporary ethical and environmental education in three steps. First, it turns to Yu Ying-Shih’s writing for a historical and ethical picture of tianrenheyi as an ‘Axial breakthrough’ in Confucius' time and with direct relevance to Confucian person-making education. Second, it moves on to Roger Ames’ unpacking of tianrenheyi as hospitalized in a ‘correlative cosmology’ and ‘Confucian relational personhood’ to help us re-understand Confucian ‘person’ as being relational. Finally, it shows how these re-invoked philosophical–ethical–cosmological theses expose a ‘foundational individualism’ which grounds and confines current educational thinking to an anthropocentric (dis)ordering. As an alternative, this article calls for a productive symbiotic conjoining between humans and their cultural–natural environs toward nurturing today’s youth into ecologically literate, responsible, and responsive co-beings.     

CRM环境下的流程定制与再造

在当前以客户为导向的市场环境下，客户关系管理已经成为企业管理的重要内容，而CRM环境下的企业业务流程有效与否则是整个CRM是否成功的关键。文章在辨析CRM概念的基础上，对CRM环境下业务流程的定制与再造进行了讨论，并给出了金龙公司CRM具体实施过程中的有关操作实例和设想，以期能够给我国当前的CRM实施提供一些有用的借鉴。     

影响图书采访质量的因素与对策

从多层面、多角度对影响高校图书馆图书采访质量的因素进行了分析．提出了高校图书馆采访工作的应对措施,包括确保购书经费、制订合理的采访计划、建立完善的需求信息渠道、做好信息的发布和反馈工作、选购具有入藏价值的文献、择优选择图书经销商、充实采购力量、提高采访人员的业务水平等。     

H.264编码器中基于最匹配块的快速帧间模式选择方法

In H.264 encoder, all possible coding modes should be checked to choose the most appropriate mode for every macroblock, which adds a heavy computation burden to the encoder. In this paper, a fast inter-mode decision method is presented to reduce computation complexity of an H.264 encoder. By detecting the best matching block （BMB） before transform and quantization, some coding modes can be skipped and the corresponding encoding steps can be omitted for these BMBs. Meanwhile this method can also be used to detect all-zero blocks. The experimental results show that this method achieves consistently significant reduction of encoding time while keeping almost the same rate-distortion performance.     

论等级顺序理论对形态阻遏的阐释力

英语中存在多种阻遏现象,形态阻遏是其中的一种,它包括词项对派生词和曲折词缀生成词的阻遏。等级顺序理论认为在英语中派生和曲折过程是按等级顺序进行的,其顺序与形态构词过程有关。试用等级顺序理论来揭示形态阻遏是如何产生的,指出等级顺序理论对形态阻遏有一定的阐释力,并对该理论不足之处提出的修正。     

相对排序算法

排序是计算机算法设计中的重要运算,本文提出一种以相对大数右移,对应的相对小数左移的算法实现数据的排序,并给出了算法描述、实现及正确性证明。其时间复杂度为O(n2)。     

网络发令系统的构建和应用

传统调度电话下令模式逐渐不能适应现代大电网调度运行操作的需要。本文提出利用信息和网络技术,建立电网调度的网络发令系统。通过查找分析传统发令模式的弊端,确定网络发令系统在电网调度运行操作、安全管理上应具备的功能设计。     

RTP-based broadcast streaming of high definition H.264/AVC video: an error robustness evaluation

In this work, we present an evaluation of the performance and error robustness of RTP-based broadcast streaming of high-quality high-definition (HD) H.264/AVC video. Using a fully controlled IP test bed (Hillestad et al., 2005), we broadcast high-definition video over RTP/UDP, and use an IP network emulator to introduce a varying amount of randomly distributed packet loss. A high-performance network interface monitoring card is used to capture the video packets into a trace file. Purpose-built software parses the trace file, analyzes the RTP stream and assembles the correctly received NAL units into an H.264/AVC Annex B byte stream file, which is subsequently decoded by JVT JM 10.1 reference software. The proposed measurement setup is a novel, practical and intuitive approach to perform error resilience testing of real-world H.264/AVC broadcast applications. Through a series of experiments, we evaluate some of the error resilience features of the H.264/AVC standard, and see how they perform at packet loss rates from 0.01 % to 5%. The results confirmed that an appropriate slice partitioning scheme is essential to have a graceful degradation in received quality in the case of packet loss. While flexible macroblock ordering reduces the compression efficiency about 1 dB for our test material, reconstructed video quality is improved for loss rates above 0.25%.