高效率的变字长颜色编码与解码技术

提出了一种新的mB/nB(m＜n)变字长颜色编码技术,用颜色位同时作为字节头、标识位及校验位,提高了信息容量.mB位二进制串中0和的1个数差值大于2,字长映射为nB位,否则字长保持mB位,减少冗余码.随后提出了基于算术平均法的解码规则.理论分析及实测表明,该编码技术编码效率高达94％,比传统方法编码效率提高88％以上,具有很高的实用价值.     

统计机器翻译中一致性解码方法比较分析

该文对近年来统计机器翻译研究中出现的多种一致性解码方法进行比较与分析。根据现有一致性解码方法对(单个或多个)统计机器翻译系统输出结果使用方式的不同,首先将其归纳为两大类 基于翻译假设重排序的一致性解码方法和基于翻译假设重组合的一致性解码方法;然后,针对每类方法,分别回顾其最具代表性的研究工作;最后,通过在大规模中—英机器翻译评测数据上的对比实验,对该文中介绍的多种方法进行比较,并对该课题未来研究方向进行展望。     

System design of full HD MVC decoding on mesh-based multicore NoCs

Future multimedia applications such as full HD (1920 × 1080) multiview video coding (MVC) present great challenges on computing architectures. Even if with the state-of-the-art ASIC technology which can process single view HD decoding, dealing with multiple views would require times of computation capacity in proportion to the number of views, which is difficult to achieve. In this paper, we explore the system-level design space for full HD MVC applications mapped onto mesh-based multicore Network-on-Chip (NoC) architectures. To this end, we establish a simulation framework capable of simulating the combination of communication networks with computing cores. We investigate two task assignment schemes: picture-level assignment and view-level assignment. With an eight-view MVC decoding, we explore the design options with respect to network size, single-core performance and link bandwidth under both task assignment schemes. Our studies show that, to achieve a certain decoding performance, the computation capability and communication capacity should be balanced in the system. Also, to realize the eight-view HD decoding, the system only requires twice or less than twice of the single-core processing capacity required by single view decoding, thanks to the parallel computation and communication enabled by the multicore NoC architectures. Our results exhibit feasibility and potential of efficiently implementing the full HD MVC decoding on multicore NoC architectures.     

基于51单片机的无线信号编解码技术研究

针对数据帧格式固定、校验方式单一以及传输速率不便于更改等问题,提出了一种通过STC89C516RD+单片机实现的软件编解码方法。该方法通过定时器的延时来实现对数字信号的编码;通过外部中断与定时器相结合的方式进行解码,即利用接收到的脉冲信号的上升沿启动定时器工作,下降沿停止定时器工作并触发外部中断,然后读取计数寄存器的值并识别数据。实验证明,该方法的数据帧格式及校验方式灵活多变,而且可以降低无线传输系统的成本,适用于无线控制、数据采集、故障报警等多种无线数据通信场合。     

自适应Viterbi译码器技术

随着现代通信技术的迅速发展,高速和高可靠性成为衡量信息传输质量的关键指标。信道编码技术能够对信道差错进行控制,降低误码率,实现可靠通信,具有重要的军事和民用意义。Viterbi译码算法及其实现技术是信道编码技术的一个重要组成部分,但是其存在自身的缺陷或不足。Viterbi译码算法的译码性能将会随着码的相关长度k增加而提高,但其实现的复杂度将以2k的比例增长。提出了一种自适应Viterbi译码算法——IAVA(Improved Adaptive Viterbi Algorithm)。该算法利用信噪比评估模块自适应地调整门限值的高低,并利用复杂度评估模块自适应地改变译码器的基状态数,从而合理利用硬件资源。当译码器工作于低信噪比环境中时门限被自动调高,保证译码性能的同时适当减少了译码器的复杂度;当工作于高信噪比环境中时门限被自动调低,此时译码器复杂度得到锐减,译码模式将切换到基-4模式从而提高了译码速度,因此在大动态信噪比环境下该算法具有优越的性能。     

A new linguistic decoding method for online handwritten Chinese character recognition

This paper presents a new linguistic decoding method for online hadwritten Chinese character recognition.The method employs a hybrid language model which combines N-gram and linguistic rules by rule quantification technique,The linguistic decoding algorithm consists of three stages:word lattice construction,the optimal sentence hypothesis search and self-adaptive learning mechanism.The technique has been applied to palmtop computer‘s online handwritten chinese character recognition.Samples containing millions of characters were used to test the acter recognition,Samples containing millions of characters were used to test the linguistic decoder.In the open experiment,accuracy rate up to 92% is acieved.and the error rate is reduced by 68%.     

A model-based hand gesture recognition system

This paper introduces a model-based hand gesture recognition system, which consists of three phases: feature extraction, training, and recognition. In the feature extraction phase, a hybrid technique combines the spatial (edge) and the temporal (motion) information of each frame to extract the feature images. Then, in the training phase, we use the principal component analysis (PCA) to characterize spatial shape variations and the hidden Markov models (HMM) to describe the temporal shape variations. A modified Hausdorff distance measurement is also applied to measure the similarity between the feature images and the pre-stored PCA models. The similarity measures are referred to as the possible observations for each frame. Finally, in recognition phase, with the pre-trained PCA models and HMM, we can generate the observation patterns from the input sequences, and then apply the Viterbi algorithm to identify the gesture. In the experiments, we prove that our method can recognize 18 different continuous gestures effectively. Received: 19 May 1999 / Accepted: 4 September 2000     

高速并行RS编译码系统实现系统

给出了一种高速并行RS编译码系统的实现方法,并就其中的几个关键技术进行了分析。采用该技术实现的纠错系统,可以使误码率在10^-3的情况下仍保证数据的高可靠,高速率传输。     

基于Nios Ⅱ的多功能数码相框

介绍了基于Nios Ⅱ的多功能数码相框的实现。系统基于Nios Ⅱ处理器,设计用户自定义模块,构建了灵活性高、可重配置的SoPC系统。设计自定义模块控制LCM显示;采用流水线方式设计JPEG解码自定义模块以提高解码效率;根据SD协议设计SD卡控制器扩展SD卡。实现了FAT16文件系统,便于对SD卡进行文件管理及多平台上的数据交换,并使用μC/OS-Ⅱ操作系统简化软件设计复杂度、提高系统稳定性。最终实现可播放音频并能显示、缩放、旋转图像且带有图像切换特效的多功能数码相框。     

基于Android的视频监控系统设计与实现

提出了一种基于Android平台的视频监控系统方法。阐述了系统的结构框架,介绍了An-droid操作系统及其应用层的开发,重点描述了PDA端视频处理的实现。系统采用Blackfin533芯片实现对视频的H.264编码,并应用快速模式选择算法优化编码过程,可使通信模块和数据处理模块通过Android平台代码完成。在3G无线网络环境下,实现了后台对远端的实时视频监控。测试表明,延迟可控制在5 s以内。