基于Linux的ARM与FPGA数据通信设计与实现

ARM与FPGA是目前应用于嵌入式开发的两款主要芯片,ARM偏向于控制领域,而FPGA偏向数据处理。为实现两者的协同工作以及数据通信,介绍了一种通信接口方案的设计与实现。在ARM上运行嵌入式Linux系统的情况下,将FPGA作为字符设备,对两者之间的接口进行驱动程序开发,包括数据总线驱动和GPIO控制驱动。用户应用程序通过调用驱动中定义好的操作函数,便可实现两者的数据通信。最后利用自定义的通信方案对接口进行测试,实现了ARM对FPGA设备的命令控制以及正确稳定的并行数据传输。     

Effects of special drill bits on drilling-induced delamination of composite materials

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for joining structures. Delamination is among the serious concerns during drilling. Practical experience proves the advantage of using such special drills as saw drill, candle stick drill, core drill and step drill. The experimental investigation described in this paper examines the theoretical predictions of critical thrust force at the onset of delamination, and compares the effects of these different drill bits. The results confirm the analytical findings and are consistent with the industrial experience. Ultrasonic scanning is used to evaluate the extent of drilling-induced delamination. The advantage of these special drills is illustrated mathematically as well as experimentally, that their thrust force is distributed toward the drill periphery instead of being concentrated at the center. The allowable feed rate without causing delamination is also increased. The analysis can be extended to examine the effects of other future innovative drill bits.     

铁基形状记忆合金（待续）

简介形状记忆效应(SME)的基本概念和形状记忆合金的发展。评述了Fe-Mn-Si,Fe-Mn-Si-Cr-Ni,Fe-Ni-Co-Ti和Fe-Ni-C等系铁基形状记忆合金的生长背景,特性及其SME的机制。     

中国的铸造生产能力与铸件出口贸易

2001年度中国灰铸铁，铸钢和可锻铸铁三类铸件的产量均大于或相当于日、美、德三国同类铸件产量的总和。尚欠发达的中国相关工业如何能为如此巨大的铸造工业提供足够的订单?美国按相关工业分类预测铸件年需求量的经验值得我们借鉴。中国铸件出口以廉价低档铸件为主，量值长期在低位徘徊的局面应予改变。2003年度美国各类进口铸件预计可达220万t，销售总金额约为40亿美元。     

Computing Minimum Area Homologies

Calculating and categorizing the similarity of curves is a fundamental problem which has generated much recent interest. However, to date there are no implementations of these algorithms for curves on surfaces with provable guarantees on the quality of the measure. In this paper, we present a similarity measure for any two cycles that are homologous, where we calculate the minimum area of any homology (or connected bounding chain) between the two cycles. The minimum area homology exists for broader classes of cycles than previous measures which are based on homotopy. It is also much easier to compute than previously defined measures, yielding an efficient implementation that is based on linear algebra tools. We demonstrate our algorithm on a range of inputs, showing examples which highlight the feasibility of this similarity measure.     

数据流语言中数据频率的自动化处理技术

数据流分析和处理是计算机应用最常见的工作之一,实际系统常常包括不同频率的数据流,而现有的程序语言要求在程序中对数据频率进行显式的处理.旨在提出一种新型的变频数据流处理框架,针对基本的频率运算进行自动化处理.我们基于函数式程序设计语言和依赖类型系统理论,定义了数据流语言FStream,在程序的类型检查过程中对数据流频率进行检查和处理,并给出了离散的Simulink模型到FStream的表示.     

Designing Camera Networks by Convex Quadratic Programming

In this paper, we study the problem of automatic camera placement for computer graphics and computer vision applications. We extend the problem formulations of previous work by proposing a novel way to incorporate visibility constraints and camera‐to‐camera relationships. For example, the placement solution can be encouraged to have cameras that image the same important locations from different viewing directions, which can enable reconstruction and surveillance tasks to perform better. We show that the general camera placement problem can be formulated mathematically as a convex binary quadratic program (BQP) under linear constraints. Moreover, we propose an optimization strategy with a favorable trade‐off between speed and solution quality. Our solution is almost as fast as a greedy treatment of the problem, but the quality is significantly higher, so much so that it is comparable to exact solutions that take orders of magnitude more computation time. Because it is computationally attractive, our method also allows users to explore the space of solutions for variations in input parameters. To evaluate its effectiveness, we show a range of 3D results on real‐world floorplans (garage, hotel, mall, and airport).     

载人航天器系统测试智能通用化数字接口设计

航天器系统接口种类和数量繁多,以往的测试系统需要针对卫星接口进行专门地面测试设备接口设计,工作量大,通用性差;为提高系统设计效率,文章提出了一种基于PXI总线技术的高性能通用数字接口模块设计方法,在给出模块结构的基础上,详细介绍了该模块的硬件主体及接口设计原理,并给出了软件设计策略及用户接口函数的定义;该模块具备多通道、大数据量同时收发的功能,已成功地应用于多个型号的测试系统;经过应用验证,该模块能够满足测试系统的使用需求.     

A metamodeling approach for pattern specification and management

The formal specification of design patterns is central to pattern research and is the foundation of solving various pattern-related problems.In this paper,we propose a metamodeling approach for pattern specification,in which a pattern is modeled as a meta-level class and its participants are meta-level references.Instead of defining a new metamodel,we reuse the Unified Modeling Language(UML)metamodel and incorporate the concepts of Variable and Set into our approach,which are unavailable in the UML but essential for pattern specification.Our approach provides straightforward solutions for pattern-related problems,such as pattern instantiation,evolution,and implementation.By integrating the solutions into a single framework,we can construct a pattern management system,in which patterns can be instantiated,evolved,and implemented in a correct and manageable way.     

动态脚本语言Lua与C++交互方法的研究与实现

针对当前利用C＋＋开发大型复杂程序代价高、周期长的问题,为了充分发挥Lua动态脚本语言的特点。重点探讨了如何在Lua脚本中模拟消息事件机制和Lua访问C＋＋接口的具体实现方法以及Lua调试器的设计方案。