一种振动自供能无线传感器的电源管理电路

针对振动能量采集器的输出功率过低不足以直接驱动无线传感器的问题,设计了振动自供能无线传感器的电源管理电路,根据调谐和阻抗变换原理对能量采集器进行了阻抗匹配,以最大功率对储能超级电容进行充电,对能量存储和电源管理电路的充放电特性进行了理论分析和实验验证。结果表明,该电路大幅度提高了采集器的输出功率和对储能超级电容充电的效率,当0.47 F超级电容电压达到0.6 V时,能量瞬间释放电路控制超级电容瞬间放电,成功驱动最大功耗为75 mW的无线传感器工作。     

一种支持外部控制的动态电源管理方法

为降低微控制器(MCU)应用系统的功耗,节省硬件资源,提出了一种新型的动态电源管理方法。该动态电源管理方法在支持内部软件控制MCU系统内部电源域的基础上,扩展支持了外部设备对MCU系统内部电源域的控制;外部设备能够根据实际的应用场景实时通过通信电路对MCU系统内部电源域进行开启或关断控制;通信电路使用的通信端口与外部唤醒端口复用一个IO端口。仿真结果表明,对比传统门控时钟的低功耗方法,采用该动态电源管理方法在降低驱动电机的通用MCU系统的静态功耗方面有显著作用:在脉宽调制模块(PWM)稳定工作和待机状态时,系统总静态功耗分别降低了27.43%和98.18%。有效降低了MCU的系统功耗,节省了硬件资源,提高了对MCU内部电源域控制的灵活性和高效性。     

基于CC430的低功耗无线交通数据采集系统

针对智能交通流检测设计了持久耐用的无线低功耗交通数据采集系统。以TI MSP430MCU和CC1101低功耗多通道无线射频内核的CC430F5137芯片为控制核心,所设计的传感器节点可以采集路口的车流量、车辆速度和温湿度环境参数。实验研究表明,该系统具有可靠性高、超低功耗、后期管理和维护成本低等优点,具有广阔的应用前景。     

基于ZigBee的LAMOST无线控制系统设计

在LAMOST系统中,为了同时观测到4000个天体,需要控制4000个光纤单元,针对LAMOST无线控制系统中存在的问题,设计了一套基于ZigBee的无线控制系统.子节点控制板硬件设计包括电源设计和射频设计.电源设计采用开关电源,降低了子节点控制板的静态功耗;射频设计采用了阻抗匹配、电容电阻微调阻抗等关键技术,减少了信号的损失与反射,极大提高了子节点控制板的无线通信质量.针对主节点,采用了STM32+射频控制CC2530+功率放大RXF2401C的设计,提高了主节点无线发送的信号质量和接收的灵敏度.软件方面,对LAMOST控制的特征进行了研究,采用成组发送、逐一轮询的方式进行控制,采用奇偶校验、时效性查询的方法,提高了系统的通信可靠性,减少了通信时间.经试验测试,该系统具有高可靠性、高效率、低功耗等特点,可完全满足LAMOST工程上的应用.     

基于LoRa的低功耗瓦斯浓度分布式监测系统设计

针对催化燃烧式甲烷传感器功耗较高及有线瓦斯浓度监测系统安装成本高、扩展性和灵活性差、维护工作量大等问题,设计了基于LoRa的低功耗瓦斯浓度分布式监测系统,详细介绍了瓦斯浓度采集节点与LoRa智能网关的软硬件设计。瓦斯浓度采集节点采用STM32L151超低功耗系列处理器,通过电源管理模块将系统电源分为可控的3个部分,并通过功耗控制策略降低功耗:(1)单片机核心系统采用低功耗模式;(2) MJC4/2.8J甲烷检测用载体催化元件采用动态通电方式,以降低平均电流;(3)采集节点中除单片机核心系统外的其他模块按需供电。LoRa智能网关利用嵌入式实时操作系统μC/OS-II进行任务调度,使网关性能达到最优,提高CPU的利用率。测试结果表明,瓦斯浓度采集节点具有较好的数据传输性能,功耗控制策略可有效降低采集节点的平均电流,从而延长电池使用时间,降低系统维护工作量。     

水质监测无线传感器网络节点双电源设计

针对电池供电的传感器网络节点电能受限问题,设计实现了一种新型的结合太阳能电池和锂电池供电的节点双电源供电系统。设计采用IAP15F2K612S2低功耗芯片和太阳能板、锂电池;通过软件优化节点供电,采用BQ24650电源管理芯片实现对锂电池的充电控制,以单片机IAP15F2K612S2为微处理器,监测锂电池的电压放电情况,放电控制电路经过DC/DC转换模块向负载供电。测试结果显示：采用双电源供电的节点工作周期长于单电源节点,且系统能稳定输出水质监测节点需要±12,±5,3.3 V的电压要求,实现了预期设计目标。     

具有自供电功能的无线载荷测试仪设计与实现

针对运动机械设备测试时不便采用有线供电和传输信号的问题,设计实现了一种自供电式无线WiFi载荷测试仪.网络节点载荷测试仪的硬件以ARM9微处理器为核心,选用Marvell 88W8686无线网卡、载荷传感器及一些相关电路实现.自供电系统由太阳能电池、充电锂电池和控制电路构成.软件系统在Linux操作系统的支撑下,内嵌Web服务器,油井运动光杆负载的动态数据通过浏览器采集.现场测试结果表明载荷测试仪达到了实用的要求,其设计方法也可应用到类似产品的开发.     

大型起重机械在线监测的无线传感器网络节点设计

从大型起重机械结构健康监测的实际应用出发,结合无线传感器网络分布式、高鲁棒性的特点,设计了一种基于Zig Bee的可对大型起重机械长期在线监测的无线传感器节点系统,并结合LabVIEW针对节点的通信距离、数据传输可靠性以及功耗等进行了现场实验,证明了节点能够很好地完成结构健康监测数据的采集与发送,能够满足在实际现场环境中大型起重机械结构健康监测对通信距离和可靠性以及节点功耗的要求.     

超级电容器组备用电源管理方案的设计与实现

针对集散控制系统（DCS）需要具备掉电保护功能,在系统断电的情况下,对组态、过程数据进行保持的需求,对比分析了锂电池备用电源方案以及相关技术特点、难点和应用情形,设计了一套基于BQ33100芯片的超级电容器备用电源管理方案。该方案主要包括恒流充电、电压检测、电流检测、温度检测、电压均衡、SMBus串行通信、保护报警等,并利用恒流放电法对超级电容进行ESR和容值的测量,计算其健康状态。该方案应用在ECS-700系统中,经测试,该备用电源方案能够对超级电容器组进行有效的监测和管理,长期有效地为系统提供断电保护功能,确保了工业控制现场的安全。     

超低启动阈值自供电SECE电源管理电路

压电换能器通常输出微弱,使用辅助电源的自供电控制电路功耗大,其电源管理电路启动阈值高,启动速度慢,转换效率低.对同步电荷提取(SECE)电路进行建模和理论推导,提出了一种间歇性自供电控制电路原理.根据SECE电路输出的最大功率点,间歇性地给控制电路非常短时间供电,并解决了间歇供电易造成逻辑混乱的问题,大幅度减小自供电电路的功耗,提高电路的效率,电路在极低输入功率下也能快速启动.实验结果表明,在压电换能器输出21 Hz、3.6 V电压时,控制电路功耗低至0.19 μW,是常规控制电路总功耗的1/134;管理电路的启动功率阈值仅为0.39 μW,低于通常电路的1/14.该控制电路的工作原理也适用于其他容性内阻换能器的微弱能量采集和高效管理电路.     

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.