基于Lora的智慧农业移动端系统设计

针对现存农业物联网的各项问题,如前期开发和后期维护成本高、系统复杂农业生产人员难以在实际生产中使用,设计了基于Lora的智慧农业移动端系统。依托于Android系统,农业生产人员或研究人员只需在Andorid手机或其他Android终端安装软件,即可实现远程对农业物联网的查看与控制。移动终端以功能进行模块划分,分别为用户管理、数据监控、设备控制和系统设置四个模块。软件使用MVP架构,将数据与界面交互进行分离;使用WebSocket协议建立云服务与移动终端的全双工通信,实现云服务对移动终端的消息推送,使得用户可以实时取得环境信息以及底层设备的故障状态;通过Retrofit2发送HTTP请求实现用户管理和对底层设备的运行控制;使用HLS协议传输监控视频。测试联调表明移动终端运行稳定可靠,易于扩展。     

基于MQTT协议的物联网岸电监控系统

目前港口岸电系统地域分布较广且供电运行数据无法及时掌握。针对这一问题,设计并开发一种基于MQTT协议的物联网岸电监控系统,利用前端数据采集装置对供电系统的供电运行参数、用户信息、电力信息、设备状态等数据进行实时采集,经过数据处理和封装打包后,采用移动4G模块将封装好的数据通过MQTT协议上传至云端服务器,数据传输采用MD5数据加密算法,实现前端数据采集设备和监控系统之间的可靠数据通信,实时监控岸电系统运行状态,同时利用手机App对岸电系统参数进行实时监控与参数修改,增强物联网岸电监控系统的灵活性和便捷性。     

保鲜车状态远程监控系统设计

保鲜车状态远程监控系统由车载监测终端和远程监控终端两部分组成。车载监测终端实时测量车厢内的温湿度和保鲜车的位置,通过GPRS模块将测量信息发送到MQTT服务器;远程监控终端采用嵌入式Linux系统,通过网卡模块从MQTT服务器获取测量信息,并通过网卡使用HTTP协议调用腾讯地图接口,解码地图数据,将车辆在地图上的实时位置和温湿度数据呈现在远程监控端,便于监控,并可通过触摸屏更改显示地图的范围大小以及温湿度阈值等,进行超限报警及相应控制。该系统为远程数据监控提供了一种便携、可靠、显示直观、易于实现的解决方案。     

无线通信网络的电力系统设备远程实时监控系统

为提高电力系统设备监测准确性和网络传输性能,设计了无线通信网络的电力系统设备远程实时监控系统.首先采用无线通信采集电力系统设备现场数据,监控终端将该数据传输到移动基站,然后通过服务器传输到以太网中,并把数据分别传输至监控工作站等模块,从而实现电力系统设备远程实时监控.经验证,该系统在网络通信方面具有传输成功率高、速度快、误码率低等优势,在监控效果方面具有监控结果准确,抗环境因素影响能力强等特点.     

基于Air724UG模组的农业大棚远程监控系统设计

本文基于上海合宙科技有限公司生产的Air724UG LTE Cat.1模块,搭配STC8单片机及其外围电路,实现了农业大棚的远程监控.该系统分为云上平台和云下平台,两个平台以MQTT协议连接和通信,大棚内的环境参量可以实时传送到云端,处理后的数据又可以反向作用于云下平台,管理人员可灵活通过Web客户端或移动终端实现对大棚的远程监控,高效便捷.经测试,本系统具备性价比高、跨平台、易构建的特点,可满足一般场景应用.     

云平台下的植物养护微信小程序设计与实现

随着移动互联网的进一步发展,网络通信速度不断提高,为基于云平台的智能控制植物养护系统的实施提供了技术基础,通过远程云平台服务器端保存数据,采用微信小程序作为前端交互程序,代替原生Android应用程序,可以在苹果iOS平台设备上运行,扩大了客户端的应用范围,从根本上解决了Android应用程序加密发布和更新繁锁的问题。微信小程序主要包括了状态查询、视频监控、阀值设置、植物选型和种植交流等功能。服务器端包括了用户信息管理、植物信息管理、种植新闻信息管理等功能。实时采集的传感器数据采用环境监控云平台进行远程保存,调用开放的API接口获取指定时间范围内的数据,大大降低了物联网开发运维成本。     

基于Android的实时移动视频监控客户端

提出了一种基于Android系统的实时视频监控系统客户端的设计实现方案。系统采用Vitamio作为多媒体开发框架,传输模块采用RTP/RTSP协议。分别从流媒体设备地址管理模块、流媒体视频播放模块和摄像头取景串流模块3个部分阐述了完整的移动图像视频采集、压缩、传输系统。实验结果表明,该移动视频终端具有压缩性能好,视频图像清晰、实时性能好等特点,可以满足实际监控项目应用场景。     

基于MQTT协议的智慧农场智能化管理系统

智慧农场的运用成为当代农业发展的必然趋势,利用MQTT协议的消息发布/订阅机制,通过远程移动端设备监控智慧农场各项数据并对智慧农场实施智能化管理十分有必要.在智慧农场中,MQTT协议网络接口可通过开发板中的代码移植和外接设备实现,以此达到智慧农场中数据与外部的交流和命令的接收,并使这些消息的交互相比其他方式更加简单快捷,实现对农场的智能控制并及时反馈的目的.     

基于Android的移动终端安全管理系统

针对Android移动终端设备安全和敏感数据泄露的问题,设计并实现基于Android的移动终端安全管理系统,允许用户远程对移动终端设备和其存储的数据进行安全管理。该系统采用C/S架构,客户端允许用户将移动终端注册到服务端,并通过在移动终端嵌入可信平台模块实现基于口令、设备和SIM卡三因素的本地用户身份识别。服务端允许用户通过Web平台对已注册的移动终端进行定位、锁定、数据加解密、数据擦除等远程安全管理。为防止用户的远程操作指令受到假冒攻击,以椭圆曲线加密和零知识证明为基础,实现移动终端对服务端的远程身份认证。实验结果表明,该系统能保障移动终端设备通信安全,防止假冒攻击。     

基于MQTT的混凝土泵车机群数据接入系统设计

针对远程数据采集和解析过程中各设备制造企业数据协议不一致的问题,设计了一种基于MQTT的混凝土泵车机群数据接入系统。该系统基于MQTT设计了统一的应用层消息协议,边缘层采用蜂窝网络进行远程数据传输。服务器端采用分布式和集群架构高速处理超大并发数据,利用配置和脚本结合的方式实现了对新数据协议的高度可扩展。数据接入测试实验验证了本系统的有效性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate