“信号与系统的结构与解释”课程的教学体会

＂信号与系统的结构与解释＂作为＂信号与系统＂和＂数字信号处理＂课程之间的桥梁,是美国加州大学伯克利分校近几年开设的一门新课程。本文较系统地介绍了该课程的讲授内容和考核题目的形式,以及在我校开设选修课的体会。最后,给出对学生的无记名调查问卷内容和统计分析。     

基于FPGA的图像中值滤波器的硬件实现

为了实现图像的实时处理,常采用现场可编程门列阵FPGA对采集的数字图像做预处理,在讨论中值滤波算法原理的基础上,利用VHDL硬件描述语言设计一个中值滤波模块对输入图像进行去噪处理,仿真结果说明该算法满足实时性要求,取得较好的仿真效果,并对中值滤波的改进算法进行了讨论。     

基于深度学习方面自然语言处理技术(NLP)的研究

深度学习方面自然语言处理技术目前已经成为主要研究热点。从深度学习和自然语言处理的概念出发,深入研究基于深度学习方面自然语言处理技术的优势以及面临的挑战,并在此基础之上对其发展进行了展望。     

AI虚拟数字人技术在融合媒体生产中的运用

重大活动无线电安全保障肩负着贯彻国家安全战略,维护社会稳定,维护国家形象的重要使命。通过对重大活动无线电安全保障工作内容的梳理,深化对无线电保障工作的认识,更好地服务于今后的重大活动无线电保障工作。     

On chip novel video streaming system for bi-network multicasting protocols

In the past three decades, tremendous Ethernet-related research has been done, which has led to today's ubiquitous Ethernet technology. On the other hand, with the emergence of new network needs, a new protocol, the IEEE 1394 standard serial bus (or Firewire) was introduced. Firewire is suitable for high-quality audio/video applications which do not perform well in the best-effort-based Ethernet technology. However, since Firewire is a serial bus, it has harsh cable length limitations as compared to Ethernet capabilities.In this paper, we present a novel on-chip system that receives Firewire video and transmits it in multicast mode using Ethernet protocol. A major advantage of this novel system is to utilize the existing Ethernet infrastructure to extend the range of Firewire video streaming to reach remote nodes and make it even accessible to nodes with a single Ethernet interface. This will have tremendous impact on Firewire applications such as deploying Firewire cameras in big-scale security-sensitive buildings or industrial facilities with image-based remote quality control.This novel chip utilizes the concept of Ethernet multicasting transmission mode for video streaming. The proposed chip design converts the IEEE 1394 isochronous traffic to the Ethernet multicast frame format via two off-chip asynchronous write and read buffers.The goal of this research is to design an On Chip Novel Video Streaming System that avoids performance bottlenecks in the software protocol conversion of these two important network protocols. The author decided to study these two networks because of their broad use and cable power provisioning capabilities. The novel system design is implemented using a customized field programmable gate array (FPGA), which enables the integration of various system components on one chip. The designed prototype is studied using both network monitoring tools and analytical techniques, to verify its function and compare it with the existing approaches.Performance measures show that the On Chip Novel Video Streaming System consumes less than 21 mW of power for 100 Mbps and 82 mW of power for 1 Gbps, and utilizes 57% of a Xilinx Spartan 2-100E-6FT256 FPGA resources. Hence, it is possible to incorporate further extensions. Experimental results show that 88% of the network utilization can be achieved, due to the use of the customized, FPGA-based design of bi-network traffic conversion.     

基于VHDL的多功能可变模计数器设计

可变模计数器作为一种基本数字电路模块,在各种数字系统中应用广泛.在对现有的可变模计数器的研究基础上,在QuartusⅡ开发环境中,用VHDL语言设计一种功能更加强大的可变模计数器,它具有清零、置数、使能控制、可逆计数和可变模等功能,并且对传统的可变模计数器的计数失控问题进行研究,最终设计出一种没有计数失控缺陷的可变模计数器,并以ACEX1K系列EP1K30QC208芯片为硬件环境,验证了其各项设计功能.结果表明该设计正确,功能完整,运行稳定.     

Graph-based Lexicalized Reordering Models for Statistical Machine Translation

Lexicalized reordering models are very important components of phrasebased translation systems.By examining the reordering relationships between adjacent phrases,conventional methods learn these models from the word aligned bilingual corpus,while ignoring the effect of the number of adjacent bilingual phrases.In this paper,we propose a method to take the number of adjacent phrases into account for better estimation of reordering models.Instead of just checking whether there is one phrase adjacent to a given phrase,our method firstly uses a compact structure named reordering graph to represent all phrase segmentations of a parallel sentence,then the effect of the adjacent phrase number can be quantified in a forward-backward fashion,and finally incorporated into the estimation of reordering models.Experimental results on the NIST Chinese-English and WMT French-Spanish data sets show that our approach significantly outperforms the baseline method.     

基于FPGA的多按键状态识别系统设计

为了实时获取生产线上大量按键并发动作状态,提出一种基于FPGA的多按键状态识别系统设计。该系统设计采用VHDL语言描述,有效地解决远距离、分散、多键并发状态识别问题,并减小电路板面积和单片机的信号连接,易于对大量按键并发输入操作。给出了该系统设计方案的硬件电路设计和仿真结果。该设计已成功应用于某项目中。     

C++语言异常处理机制

对C＋＋语言的异常处理机制进行了比较详细的分析和研究，包括语法特征、动态性质、实现中的问题以及它们可能造成的影响等。     

基于Web网页语料构建动态语言模型

为语音识别系统构建语言模型，首先要进行语料准备，语料来源决定语言模型的性能。Web网页中涵盖了各种最新的语言现象，为语料准备提供了最多样化的资源。但Web网页中语义完整字串通常夹杂在格式、标记、广告等无用字串中。首先介绍语言模型的训练算法和更新方法，继而提出一种从HTML文档提取用于训练语言模型的语义完整汉字字串的算法，最后给出语料提取实验结果、语言模型训练结果和语言模型的动态更新结果。为基于Web网页语料动态更新语言模型提供了一个完整的解决方案。