基于STM32的风速监测系统设计

为了准确掌握气象动态,实时可靠获得风速信息,设计了基于STM32微控制器的风速监测系统。该系统采用三杯式风速传感器作为传感设备,STM32芯片作为主控制器,SP3485收发器和HAC-UM数传模块作为通信传输模块。给出了基于STM32风速测量技术、硬件设计的总体框架以及系统软件实现方法。通过STM32定时器捕获脉冲频率,实现了对风速实时准确的监测。经测试,该系统具有功耗低、性能稳定、测量精度高、功能扩展方便等特点。     

基于LoRa技术的网络终端无线程序升级系统研究

设计了一种基于LoRa技术的STM32F4无线程序升级系统.此系统由PC及相关STM32软件开发环境、LoRa通信模块及其控制器和STM32 F4终端三部分组成.本系统采用LoRa技术将程序数据无线发送到终端,终端通过IAP技术实现远程无线程序自动升级.测试结果表明,此系统能够有效地进行无线传感网络终端的程序升级,极大节约了时间和人力成本.     

基于STM32的无线蓝牙传输设计

项目以STM32单片机为基础,设计了一套无线传输系统。系统选用STM32F1系列单片机作为平台,利用其丰富的内部资源及外部设备,通过ST-Link仿真器进行在线调试,设计并开发应用功能,最终以HC-05蓝牙传输方式实现无线通信。实验表明,基于STM32的无线通信系统准确度高、延时小、操作方便,能够满足多种电子设备的无线功能需求。     

基于STM32与SN260的物联网数据采集与控制系统

介绍了一种基于ZigBee技术的物联网系统数据采集与控制系统．利用STM32单片机作为主控制器结合SN260无线射频zigBee网络处理器设计物联网系统的硬件节点,实现远程环境数据的采集与控制功能;并详细描述了该物联网系统的工作原理和系统设计．     

基于电磁耦合的水下无线能量传输系统

设计并实现了一种基于电磁耦合的水下无线能量传输系统。该系统采用全桥整流电路实现高频逆变,优化驱动电路,采用STM32F103VBT6处理器实现全桥PWM控制与电流监测,结合理论计算与有限元分析方法获取最优参数耦合器,进而实现电能的无线耦合传输。水下试验证明,该系统可实现有效的水下无线能量传输。     

基于STM32单片机的室内空气监测系统的设计

针对室内环境污染导致的人体健康问题，提出了一种基于STM32单片机的室内空气监测系统。该系统主要由主控制器模块、传感器模块、数据采集模块、显示模块、通讯模块等组成，通过无线方式与上位机连接实现信息传输。该系统通过采集空气中各种成分浓度信号并进行分析处理，进而实现对室内空气质量的自动监测和预警，从而有效地解决室内空气污染问题。     

基于ZigBee的大型公共建筑能耗采集器设计

针对大型公共建筑能耗实时采集系统中存在的布线复杂、通信成本高、安全性低等问题,提出一种基于ZigBee技术的能耗数据采集器设计方案。该方案采用STM32做主控制器, ZigBee采集单元通过RS485接口实现与基于Modbus协议的智能电表之间的数据通信,并采用ZigBee无线网络将数据发送至协调器,协调器通过USART方式与主控制器进行通信;主控制器利用以太网将数据发送至上位机。通过软硬件设计,以XY194E智能电表为例,对其电能参数进行测试采集,结果表明该方案克服了传统人工采集传输的不足,提高了数据采集传输的实时性、准确性,能够满足能耗采集系统的要求。     

基于STM32的电动葫芦能效测试装置的设计与实现

为方便地测试电动葫芦能效,设计了一种能效测试装置,采用基于ARM Cortex-M4内核的高性能处理器STM32F407为主控制器。针对各测量点分散的问题,采用ZigBee无线通信技术传输数据到主控制器,主控制器严格按照电动葫芦能效测试国家标准控制能效测试流程运行,并实现能效测试数据的存储和传输到远程服务器。     

基于ZigBee技术的电压采集系统的设计与实现

在智能低压电器的实际应用中,经常需要进行电压的采集,而有线采集的方法在某些场合中并不适用。提出基于ZigBee无线技术的电压采集系统的设计,利用STM32W无线射频ZigBee单片机作为主控制器,实现0～21V直流电压的采集。     

嵌入式二维码数据无线多点传输系统设计

设计了一种基于FreeRTOS嵌入式操作系统的二维条码无线传输系统,描述了系统的软硬件实现方法和多点数据传输的链路控制机制。系统主控芯片采用通用的MCU芯片STM32,结合二维码扫描引擎和蓝牙传输模组实现多个扫描终端与基座间的数据传输。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).