基于Websocket的桥梁结构变形实时监测系统设计

随着网络技术的发展,实时通信成为互联网领域的研究热点,如远程监控技术。常见的实时通信技术基本是由客户端主动发起请求,服务器端被动接受响应,此方式缺乏灵活性。Websocket技术是HTML5(HyperText Markup Language 5)提供的一种全双工通讯的计算机通信协议,具有节约带宽,持久连接,实时性等特性,采用Websocket技术的通信方案不仅能真正实现实时数据通信,还能提升服务器推送数据的能力。文中对Websocket技术进行了分析与研究。同时,随着社会与经济的快速发展,桥梁工程建设进程和建设规模不断加大,对桥梁的施工建设和运营维护提出了更高要求,所以在此过程中获取桥梁结构变形实时数据并进行监测就尤为重要。为此采用Websocket技术,设计了基于Websocket技术的桥梁结构变形远程实时监测系统,真正地实现了数据的实时交互,对桥梁施工现场及后期维护的远程监控更具可靠性与便捷性。     

基于Android的老人关爱系统

针对日益突出的老人监护需求,设计并实现了基于安卓智能手机的老人关爱系统,系统围绕老人的位置信息采集、传送、处理生成服务三个核心问题,并探讨了基于极光推送的老人救助模式.通过手机自带GPS定位功能实现了位置信息采集,自定义Json数据传送格式、调用百度API处理显示服务,实现了老人实时位置显示、历史轨迹回放、一键报警功能,系统服务端结合极光推送,可以将老人的求助信息快速推送到相关人员手机上,实现了周边救助模式,初步应用表明,该系统具有实时性强,用户参与度高,经济便捷等特点,为老人关爱领域提供了模型参考.     

基于Storm的车联网数据实时分析系统

针对传统车联网平台在处理海量数据时存在吞吐量小, 实时性差的问题, 设计了一种基于大数据流处理技术的实时分析系统. 系统分为数据采集、 数据转发、实时分析、数据存储和可视化展示5层. 为了满足系统高并发接入以及实时性的需求, 引入Storm实时计算系统进行数据的实时分析. 同时, 利用Kafka消息队列的异步通信机制将各层之间解耦, 采用Hbase进行海量数据存储, 从而提高车联网非机构化数据存储效率. 另外, 针对访问数据库开销大的问题, 采用Redis缓存策略, 进一步提高查询效率. 实验证明, 较传统的多线程处理平台, 该系统具有低延迟, 高吞吐, 可拓展等特点, 能够满足车联网大数据流处理要求.     

面向震害应急的移动GIS关键技术研究与应用

为解决震害应急救助现场数据获取困难,指挥不及时的问题,在分析震害应急救助过程的基础上,针对地震现场救助的移动性和数据实时性的需求,设计了震害应急现场指挥系统的系统架构、功能以及数据管理方式,重点研究了移动GIS的关键技术,提出了利用缓存技术,位置驱动、服务器推送技术等方法改进移动终端和数据中心的数据传输方式.实验结果表明,改进方法提高了系统的鲁棒性和实时性,可以为震害应急现场指挥提供有效地信息支持,从而提高救援效率.     

减小LoRa技术在实验室监测系统中报警延迟的方法研究

作为目前流行的物联网通信技术,LoRa在环境监测领域已有较成熟的解决方案,但其应用于对实时性要求高的场景时,例如实验室安全监测,相应方案不能展现出较好的性能。以目前成熟的LoRa解决方案为基础,在其架构的应用层与服务层间的通信中引入MQTT和Websocket技术,并在服务层中结合使用Node.js、Redis等技术,设计实现低延时实验室安全监测系统。该系统应用层包含Web端页面数据实时展示、移动端APP数据查看以及异常信息告警通知。同时,为实现集中管理多个监测区域的实际应用需求,设计数据推送策略,提高数据传输效率,进一步提高系统实时性。测试结果表明,对比现有环境监测解决方案,本系统能以更低的时延将终端数据传送至应用程序端。     

基于Android的远程医疗监测系统设计

为满足人们对于远程医疗的需求,推出了一个应用Android移动终端的解决方案。该方案结合Android系统的特点,设计了一套采集、显示存储、报警推送于一体的远程医疗监测系统。首先对Android框架与系统架构进行介绍,然后对系统涉及到的Android系统蓝牙、Socket等通信方式的开发进行分析,并对Android设备在数据采集、存储、处理中的应用进行介绍,最后应用MQTT协议完成了对报警信息的推送。结果表明Android系统在远程医疗服务系统中有很大的应用前景。     

基于CAN总线的分布式消防报警系统

为避免大型建筑消防报警系统因主机故障而全部瘫痪的危险,研究了一种多主分布式消防报警系统.采用32位MCF5282微处理器和多种8位微控制器,基于CAN总线实现了对等分布式的消防报警系统设计.首先介绍系统的结构设计,给出了主控制器和系统节点的具体实现方法;采用一种公文式数据报通讯协议,解决了多主通讯存在的数据丢失问题;最后介绍了系统软件结构和设计思想.系统在信息传输的安全性、准确性、实时性等方面达到了较高的性能指标.     

多步攻击告警关联模型构建与实现

为精简入侵检测系统产生的大量报警信息和分析攻击者的目的和动机,提出了新的报警信息关联模型。该模型通过事件关联把具有相似关系的报警信息关联后存储为元报警,然后根据报警类型知识库转换为超报警,最后根据超报警之间的因果关系进行攻击关联,构建出攻击关联图。实验表明,该模型提高了报警处理效率,对识别攻击意图和提高报警准确性有较好的效果。     

基于Android平台的实时隐秘报警系统设计与实现

为解决现有报警方式所需报警时间长、隐秘性差、定位不准确等问题,基于广泛使用的Android操作系统,使用Java语言,设计并实现了一款实时隐秘报警系统。在手机锁屏状态下,系统可在5s内通过快速按动音量上下键至震动实现自动报警,并会将报警人信息、位置、位移和现场录音推送给最近的警局。系统具有操作方便、快速报警、安全隐秘、实时定位的特点。可以很好的解决当事人遇到突发情况时不便报警的危险处境,其录音推送、定位追踪、查看报警人信息功能可协助办案人员判断案情、实施追捕。经过严格测试,系统运行稳定,具有很高的应用价值。     

基于多微处理器的智能超声探测系统

设计了一种基于多微处理器的智能超声探测系统.该系统采用由上位工作模式控制单元和下位智能超声传感器阵列组成的分布式结构.每个超声传感器均由独立的微处理器控制,并完成实时数据处理、抗干扰处理、故障报警以及数据通信等功能.上位控制单元根据移动机器人的运动状态采用不同的控制策略,使下位传感器阵列分组并行工作,提高了探测系统的实时性;下位传感器采用"阈值比较法"、"改进型递推均值滤波"算法和模糊信息处理技术,提高了探测系统的准确性、可靠性.将该探测系统安装于RIRA-Ⅱ移动机器人上,进行了基于主动视觉和超声信息的运动目标跟踪实验,实验表明超声探测系统运行可靠、稳定.     

一种利用Java进行Web网络管理的技术策略的研究

介绍了传统的网络管理模式和基于Ｗｅｂ的３层网络管理模式的区别,讨论了如何利用Ｊａｖａ技术实现Ｗｅｂ网络管理的一种方法及其工作原理,举例说明了如何实现网络管理中的拓扑发现和报警推送的问题。     

基于Android平台的多人视频聊天系统

随着互联网技术和计算机网络技术的快速发展, Android平台系统普遍应用到智能移动终端上,基于Android平台的多人视频聊天系统能使得人们在何时何地都能实现了远程多人视频聊天,提高工作效率,受到很多公司和科研机构的关注.本系统以Websocket为通信信令,利用WebRTC技术传送视频和音频,设计了多人视频聊天系统,包括了服务器及Android客户端;在同一个房间的Android客户端可以实现远程多人视频聊天.本文重点介绍了采用Websocket信令方式和利用WebRTC相关等技术实现了多人视频通信.     

Psychophysical basis for maximum pushing and pulling forces: A review and recommendations

The objective of this paper was to perform a comprehensive review of psychophysically determined maximum acceptable pushing and pulling forces. Factors affecting pushing and pulling forces are identified and discussed. Recent studies show a significant decrease (compared to previous studies) in maximum acceptable forces for males but not for females when pushing and pulling on a treadmill. A comparison of pushing and pulling forces measured using a high inertia cart with those measured on a treadmill shows that the pushing and pulling forces using high inertia cart are higher for males but are about the same for females. It is concluded that the recommendations of Snook and Ciriello (1991) for pushing and pulling forces are still valid and provide reasonable recommendations for ergonomics practitioners. Regression equations as a function of handle height, frequency of exertion and pushing/pulling distance are provided to estimate maximum initial and sustained forces for pushing and pulling acceptable to 75% male and female workers.     

TCP Socket通信与Web服务结合实现高效可靠的数据分发

针对常见的一对多数据分发场景,分析了网络的现实情况,包括NAT和防火墙等,提出使用Web服务实现数据分发。考虑到Web服务的效率问题,把由服务器使用TCP Socket推送数据技术与客户端通过Web服务获取数据技术相结合,成功实现了各种网络条件下的数据分发,并利用异步Socket方式提高了系统效率。系统实现时,考虑到各种网络故障,使用了多种方法保证了数据分发的可靠性。同时,提出了可达性测试算法,使得服务器可靠地辨别哪些客户端无法被服务器访问,从而需要客户端主动拉数据。最后给出了可靠性与效率分析,并以实例证明了系统的高效性。     

Modification of an EMG-assisted biomechanical model for pushing and pulling

Pushing and pulling tasks using carts and material handling devices have become more prevalent in occupational environments in an attempt to reduce the musculoskeletal risks associated with lifting. However, little change in low back disorder rates have been noted as tasks change from lifting to pushing and pulling indicating that we do not understand the mechanics of pushing and pulling well. Biomechanical assessments of pushing and pulling tasks using person-specific biologically assisted models offer a means to help understand how the spine is loaded under pushing and pulling conditions. However, critical components of these models must be adjusted so that they are sensitive to the different physiologic responses in the torso muscles expected during pushing and pulling compared to lifting tasks.The objective of this study was to modify an electromyography (EMG)-assisted biomechanical model designed to evaluate lifting tasks so that it can better represent the biomechanical forces expected during pushing and pulling tasks. Several key modifications were made. Based upon a literature review, changes in muscle cross-sectional area and muscle origins and insertions were made to better represent the geometry of the torso muscles. It was also necessary to adjust the length–force and velocity–force muscle relationships. Empirically derived length–force and velocity–force relationships were developed to independently represent the flexor and extensor musculature. These modifications were then systematically incorporated into the model.The model was exercised over several pushing and pulling conditions to assess the effect of these modifications on its ability to predict externally measured spinal moments. Results indicated that the alterations made to the preexisting EMG-assisted model resulted in acceptable model performance for pushing, pulling, and lifting activities.

Relevance to industry

The use of carts and material handling devices has become increasingly prevalent in industry, though little research has been done to examine the body's response. The modifications made to the biomechanical model would enable its use in the evaluation and design of material handling devices and pushing and pulling tasks.     

Pushing and pulling: personal mechanics influence spine loads

This study assessed several mechanical issues related to low back loading during pushing and/or pulling tasks. Nine male participants performed two-handed pushing and pulling tasks at two handle heights with three loads, using a cable pulley system. Four of these men were professional firefighters trained in performing pushing and pulling tasks while the other five were graduate students who lacked manual work experience. The more experienced firefighters produced less spinal compression and shearing forces when compared to the less experienced students under the same conditions. The firefighters were able to create less muscle activation as compared to the students, which indicated a more efficient technique. The main contributing factors to the forces produced on the low back were the quantity of the load being pushed or pulled, handle height, experience level and the technique of the participant. Thus, attempts to set load limits for pushing and pulling tasks are difficult, since technique has such a large influence on back loading. In order to create safer working environments, education on proper pushing and pulling techniques is very important – more important than the physical variables in many cases.     

Pushing and pulling: personal mechanics influence spine loads

This study assessed several mechanical issues related to low back loading during pushing and/or pulling tasks. Nine male participants performed two-handed pushing and pulling tasks at two handle heights with three loads, using a cable pulley system. Four of these men were professional firefighters trained in performing pushing and pulling tasks while the other five were graduate students who lacked manual work experience. The more experienced firefighters produced less spinal compression and shearing forces when compared to the less experienced students under the same conditions. The firefighters were able to create less muscle activation as compared to the students, which indicated a more efficient technique. The main contributing factors to the forces produced on the low back were the quantity of the load being pushed or pulled, handle height, experience level and the technique of the participant. Thus, attempts to set load limits for pushing and pulling tasks are difficult, since technique has such a large influence on back loading. In order to create safer working environments, education on proper pushing and pulling techniques is very important--more important than the physical variables in many cases.     

AJAX技术在山西电力内容管理系统中的应用研究

在论述AJAX技术基础上,研究基于AJAX技术实现浏览器与服务器的异步通信的技术关键,提出一种AJAX应用模型,将其应用到山西电力公司内容管理平台系统。通过性能分析,探讨多用户并发访问时多线程及资源消耗情况。最后在性能比较试验中证明此模式减少了网络时延对WEB性能的影响,在响应时间和资源利用率上有显著优势。还总结出AJAX技术在实现过程中的优缺点。     

基于ASP．NET AJAX新型Web Scada的设计与实现

传统的B／S结构下,服务器端决定交互方式,网络交互性能并不理想,而ASP．NET AJAX框架使用异步通信机制提高交互性能。讨论了ASP．NEDT AJAX的结构和核心技术,提出了基于ASP．NET AJAX框架的一种新型以太网架构的数据采集与监视系统的设计与实现方法。