基于ARM平台AMP架构下从核重复加载设计与实现

针对工业智能相机在不同工作场景的需求以及在二次开发方面的诸多不便,通过重点研究和分析基于多核ARM平台的AMP架构下主从核的启动机制,提出一种用户态从核重复加载方案,丰富了开发者解决实际工程问题的手段。以Zynq-7000为硬件平台,在双核Cortex-A9处理器上分别配置嵌入式Linux系统和Bare-Metal环境,实现了主核对从核的复位和重新唤醒控制和不同从核任务程序的自由切换,对工程应用有积极的参考价值。     

国产ARM架构芯片的多核启动方法研究

简述在ARM架构多核处理器上部署嵌入式操作系统的过程,并介绍一种主核优先启动并通过ARM异常产生指令SMC唤起从核的主从核唤起的多核启动方法。实验选用FT-2000+处理器作为目标板,通过网络加载方式载入ReWorks多核嵌入式操作系统镜像,实现多核操作系统的配置,使系统运行至用户应用入口函数中。最后通过执行测试函数与任务显示指令确认各核状态,对该多核启动方法进行验证。     

通用非对称多核方案设计

多核处理器是目前处理器发展的主流方向, 但硬实时保证方面存在诸多挑战. 通过研究分析实时应用需求和多核处理器的应用现状, 提出一种基于通用处理器的非对称多核方案. 重点讨论了方案的软件总体设计、共享资源管理、非对称多核模式下的从核镜像加载、启动和核间通信的设计. 采用通用非对称多核方案研制的低压保护测控装置, 其现场运行情况表明方案满足电力二次设备的实时性能要求.     

异构处理器多操作系统协同技术研究

随着嵌入式设备应用场景日趋复杂的变化,异构多核架构逐渐成为嵌入式处理器的主流架构.目前,多核处理器主要采用的单操作系统模式在实际应用中存在诸多局限性.为了充分发挥异构处理器的多核特性,针对异构处理器不同核部署相应的操作系统并实现多操作系统协同处理技术至关重要.本文对异构多核处理器（ARM+DSP）操作系统进行了研究,在异构多核平台上成功移植了嵌入式Linux和国产DSP实时操作系统ReWorks;为实现ReWorks与Linux操作系统协同处理,本文对核间通信的关键技术进行分析研究,并以TI公司的AM5718为例,设计了一系列多核异构通信组件.经测试,本文设计的异构通信组件实现了在ARM上对DSP核进行ReWorks操作系统和应用程序的动态加载、Linux与ReWorks核间消息收发、以及Linux与ReWorks的协同计算等功能.     

基于多核处理器的TCP/IP协议栈加速技术

多核处理器已经成为了处理器发展的趋势.在多核处理器上运行Linux操作系统时,由于所有的TCP/IP网络协议处理都以软件的形式在Linux操作系统内核运行,处理效率很低.为了解决这个问题,本文提出了一种基于多核处理器的多核TCP/IP加速协议栈,将多核处理器的处理核心分成两部分.一部分运行Linux操作系统.另一部分处理核心运行实时系统,处理TCP/IP协议栈.由于将TCP/IP协议栈的处理卸载到了实时系统,Linux的中断处理大大减少,并且实时系统直接操作底层硬件资源,没有操作系统的参与,所以多核TCP/IP加速协议栈的处理效率会很高.通实验结果对比,在相同的硬件资源下,多核TCP/IP加速协议栈不仅比Linux TCP/IP协议栈获得了更大的网络处理吞吐率,而且消耗了更低的CPU.     

网络路由加速平台的设计与实现

网络路由加速平台是一个基于多核处理器的软件平台,实现网络数据报文的快速接收、快速处理、快速输出转发。该软件平台运行在多核处理器上,采用混合模式,一个core运行Linux操作系统作为控制平面,其余的core运行SE做为数据处理平面。该软件平台充分利用了Linux和SE本身所具有的特点,既发挥了Linux系统化管理和调度的优势,又简化了代码的开发结构,提高了数据转发效率,使得平台处理得以加速,可以应用于基于多核处理器的路由器、SDN、防火墙和负载均衡等通信产品。     

多核虚拟机监控系统

随着多核处理器时代的到来,虚拟化技术被广泛使用,而多核虚拟机就是其中一种.目前多核虚拟机监控一般都是采用硬件虚拟化的技术,即通过虚拟化技术虚拟出多个串口来达到监控目的.给出一种基于系统级共享内存的多核虚拟化监控系统方案,并提供了完整的设计与实现方案.     

针对搜索服务的操作系统伸缩性研究

分析当前成熟操作系统,找出其在多核环境下的性能瓶颈并进行改进,已经成为了现代操作系统研究的重点之一.通过搜索服务压力测试实验发现,运行Nginx反向代理的64核Linux服务器的伸缩性不佳,启用64核时的吞吐量仅是1核时的3倍.瓶颈在于服务器上所有网卡中断和软中断处理都集中在一个CPU核上.结合网卡的Flow Direction机制和Linux内核中断的亲和性配置,实现了网卡中断负载均衡的方法,系统吞吐量提升33％.多核环境下网卡中断负载均衡无法保证TCP连接的亲和性.通过修改Linux内核代码,解决了TCP连接的非亲和性问题,系统吞吐量在之前的提升基础上,又提升9％.     

片上Trace辅助的嵌入式多核程序分析与调优

YHFT-QDSP是一款多核处理器,TraceDo是其实时片上追踪调试系统。本文首先将串行二维快速傅立叶变换算法(2D-FFT)并行化,映射于该多核处理器;并基于可视化的TraceDo系统,从多核程序同步及核间数据传输两个方面深入分析了并行2D-FFT程序行为;而后提出并实现了两种性能优化(调优)方案。实例研究表明,TraceDo系统可有效地提高嵌入式多核程序的开发效率。     

Linux系统中多核实时调度平台的设计

为使各种实时调度算法能够在Linux环境中得到运行和验证,设计一种Linux系统中的公共多核调度平台。该平台由调度模块和跟踪测试模块组成,调度模块实现系统调用、调度处理以及同步功能,跟踪测试模块实现日志和跟踪功能。测试结果表明,该平台可正确显示调度算法的运行结果。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.