鸡舍LED光色智能系统的设计与研究

为解决当前鸡舍内光色调控智能化和精准化较低的问题,设计了应用于鸡舍的光色可调控系统,提出了一种以常见芯片STC89C52单片机为微处理器,以节能高效的LED灯珠作为光色调控系统的发光源,以牛顿三原色光为基本原理的多色调光系统。系统可定时定量对不同生长期下肉鸡进行精确补光,系统设置时以秒为最小量度,自由设置光照时间阀值,并以PWN调光方式控制LED的电流来调控红、蓝、绿光的亮度,经试验验证,系统能精确发出红、蓝、绿等色光,进而调控产生黄、青、白等色光。利用SAS软件,对试验肉鸡增重数据进行处理,育雏期和生长期的鸡只,在波长为450-490nm的蓝光照射下增重明显,数据显著（P<0.05）。本系统可满足鸡舍中肉鸡补光的精确需求,高效环保,可稳定实现节能化补光,解决了鸡舍内光照精准化较低的问题,对鸡舍数字化、智能化提供了新思路。     

基于植物专家系统的智能LED光照控制系统设计

光照度是植物生长的重要环境因素。目前,我国植物工厂的光照控制大多使用基于传统光源的简单控制模式;即使少数使用了LED光源的系统,也只是采用了定波长、定光强的LED光源。为提供适合植物生长的光环境,设计了基于植物专家系统的智能LED光照控制系统。该系统采用红、蓝和远红外3色光LED组成的发光模块控制光照。植物专家依据不同生长期植物对光谱的选择性吸收特点,设定各色光在各生长期的光照度;以单片机为核心的控制系统实时检测环境光照度,并与专家设定值进行比较,计算实际调光量;由脉宽调制(PWM)信号控制发光模块各色光光照度。控制系统具有光照度超限报警及温湿度自动控制的功能,既可以实现光环境的自动控制,也可以根据用户需要灵活调控,具有操作简便、控制精确、能源利用率高的特点。     

基于Freescale微控制器的AOI多彩照明控制系统

为了检测出高密度印刷电路板(HDI PCB)中的多种焊接缺陷,对用于自动光学检测(AOI)设备的多角度多色彩LED照明装置的控制系统进行软硬件改进,设计了一种以Freescale--MC9H12XS128为微控制器的多彩照明控制系统。控制系统的硬件结构简单,可同时对4组LED阵列进行脉宽调制控制,根据实际图像的提取效果,通过接收主控上位机发出的指令,对不同LED阵列进行颜色选择和256级光照亮度的调节。实验结果表明,该系统能满足AOI设备对照明装置提出的各种要求,使照明系统光照均匀,光强可调,响应快,发热量小。     

基于LED光源靶向驱虫系统设计与开发

光触媒方式是当前对环境污染最小的绿色环保技术,如何实现靶向驱虫是现有的物理防治害虫技术的难点,本文进行了一种靶向驱虫智能控制系统的研究。通过调整LED光源的波长和强度开发靶向驱虫系统,利用单片机采集芯片和光敏传感器的数据,实现对于害虫的定向驱逐。物理法定向驱逐害虫,避免了化学法驱逐害虫的污染问题和生态平衡问题。对有益、有害及其他昆虫的定向防治奠定新的理论和应用基础。     

反射式叶绿素仪的系统设计

本文主要阐述了测量叶片当中的叶绿素含量的反射式叶绿素仪的系统设计。仪器由三大部分组成,分别为光学系统设计、硬件电路设计和软件设计。系统光源采用双波长LED,LED光源采用调制方式供电来消除杂散光的影响。光学系统运用两个检测器检测两种不同的光,一个检测器是直接检测从光源发出的光,另一个检测器是检测发射光通过叶片反射回来的光,并对两种光强进行计算,最终得出叶片当中叶绿素浓度。     

基于ArcIMS的海洋内波信息系统设计与实现

海洋内波信息系统主要用来管理和发布海洋内波数据,并通过Internet/Intranet面向特定用户提供内波空间查询和专题应用功能的信息系统。在阐述网络地理信息系统(WebGIS)开发平台ArcIMS 9.2体系结构和功能的基础上,详细介绍了海洋内波信息系统的设计,包括平台和技术路线的选择、系统的数据体系、实现流程和系统功能模块等,并在此基础上完成了海洋内波信息系统的开发。利用本系统,授权用户可以通过网络查询特定区域海洋内波的空间分布和不同空间位置上海洋内波的波速、波长、振幅、波向、时间分布等信息。该系统还能根据用户特定需求生成海洋内波信息专题图和海洋内波分布专题图,为需要内波信息的部门提供重要的决策依据。     

基于PSoC的瞳孔光刺激与测量系统

瞳孔跟随光刺激的变换检测系统可广泛用于疲劳检测、颅内损伤检测等方面。为实现方便可控的刺激光源生成和光强检测,设计实现基于PSoC（Programmable System on Chip,片上可编程系统）芯片的光刺激与测量系统。以PWM（脉冲宽度调制）的方式驱动LED,PC端设计了应用控制界面,可以调节LED光照刺激的强度频率等参数,并实时获得光强数据。系统实际运用于实时瞳孔参数检测平台,提供稳定可控的光刺激与测量功能。     

基于LED的星内光无线CAN通信系统的设计

描述了一个利用LED实现的星内光无线CAN通信系统.通过光收发电路代替有线CAN通信的收发器部分,实现了基于LED的光无线CAN通信.所实现系统在器件选用、功耗等方面尽可能考虑了在轨应用可行性.实验结果表明,所实现基于LED的星内光无线CAN通信系统在漫反射通信状态设备间距离为0.5m时,通信速率最高可达100 kb/s,可应用于卫星内部特定载荷之间的CAN通信.     

照度稳定的LED工作台设计

本文设计并制作一个照度稳定可调LED工作台,使该工作台能够按照周围环境光自行连续调整LIED灯珠亮度并使目标照度始终稳定地保持在要求内,以适应各种特殊工作要求。设计以STM32F103ZET6单I片机为中心,利用BH1750FV光照传感器进行照度采集,并将采集到的照度数据通过串口发送给单片机,单片机对数据进行分析并使用PD算法进行PWM调光,控制工作台在外部光源干扰的条件下进行明暗变化,并使得工作台中心光照稳定度和均匀度变化范围±10%之内。经过多次测试表明,所采用的设计方案实时有效,满足系统设计指标要求。     

用于光遗传技术的体外细胞光刺激系统

光遗传技术具有在毫秒水平上精细调控某种特定细胞亚群活性的优势,对神经回路和某些神经系统疾病的发病机制和干预治疗等基础研究提供了一个崭新的生物工程学工具。文章基于光遗传技术的特点,研发了一套针对光感基因改造过体外培养细胞与离体脑片LED光刺激系统,实现远程无线控制LED整列的刺激时间、频率、占空比等参数,并同步检测培养细胞的理化特性。     

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).