施药机械药液自动混合控制系统的研究

化学农药在农业生产中有着重要作用,是保证农业生产实现稳产、高产的重要措施之一。目前我国农药大都是采用人工进行配置,存在浪费、农药易失效、不安全等问题,本文通过对电磁阀开关混合控制和电动阀变量控制两种农药混合系统进行比较,电磁阀开关混合控制系统具有混合效果稳定、易操作、结构简单、残留农药易清理等优点,故适合在实际推广中使用。     

Crowdsourcing mode-based learning activity flow approach to promote subject ontology generation and evolution in learning

ABSTRACT

Subject ontology can help implement the structured organization of knowledge for online learners and thus plays an important role in the learning process. However, building ontologies by experts is time-consuming, and the adaptation of such ontologies to different contexts might be a problem. Crowdsourcing, which allows users to build and refine ontologies during their learning process, has exhibited potential for solving this problem. In this study, a crowdsourcing mode-based learning activity flow approach is proposed to guide the learning of online learners while promoting the generation and evolution of subject ontologies using the learners’ contributions to the learning content. This flow makes full use of the learners’ wisdom during the learning process to promote self-regulated learning as well as the generation and evolution of the ontology. Based on the proposed approach, a learning support system was developed and an experiment conducted involving a Chinese lesson on “The Liangzhou Poem”. In the experiment, student participants built 722 triples, of which 584 evolved as formal items in the subject ontology. Moreover, all learners were able to construct a well-organized knowledge graph. Students in both high- and low-scoring groups contributed valuably to the knowledge generation and evolution of the subject ontology. Furthermore, while the widths of the knowledge constructed by students in high- and low-scoring groups were similar, their depths were substantially different. During this process, the crowdsourcing-based activity flow system achieved satisfactory technique acceptance, which means that the proposed approach and system are useful for the effective generation of subject ontologies while helping learners acquire knowledge.     

基于OPNET的流媒体应用流量特征分析

针对不同工作模式的流媒体应用数据流,根据报文大小、IP地址和端口识别出流媒体应用有效数据,分析了流媒体应用流量包的大小、数量和报文长度分布等特征.利用OPNET对不同模式的流媒体流量特征数据进行分析,提取多种流行流媒体应用的行为特征.     

基于Web的科研信息管理信息系统

开发一个基于C/S和B/S两种模式架构的高校科研管理信息系统,主要采用ASP.NET、PowerBuilder、C#、SQL Server 2000数据库等相关技术作为项目实施的技术支撑,并运用软件工程的方法给出了系统的模块设计流程,利用现有"一卡通"系统的统一身份认证平台完成用户认证,保证了系统的安全性。通过系统应用效果分析得出该系统,对于高校的网络化科研管理具有一定的理论意义和实践价值。     

教师定期流动政策执行的实证调查研究——基于政策工具视角

通过问卷调查对教师定期流动政策的执行过程进行实证研究,以政策工具理论为指导,基于政策工具视角对政策执行过程的实证调查进行分析与讨论.在优化政策工具方面从完善其管理环境、制度环境、监督环境着手,探索将政策意图转变为管理行为、将政策理想转变为政策现实的最佳工具,尤其是2011年重庆市《义务教育条例》颁布并逐步推行后,更需寻求使现有教师流动机制更高效、更完善、更有效的工具路径.     

气流能量方程及其应用

用流体运动微分方程建立能量方程,讨论绝热压缩气流能量方程及应用,并对低速气流按不可压缩流体计算所产生的误差进行了分析.     

Lean information for lean communication: Analysis of concepts,tools, references,and terms

Communication and information processes are vital in any company. The use of lean manufacturing concepts applied to the communication and information process aims to reduce waste and make the flows leaner and simpler. Lean information is a new strand of lean concepts and applications. The purpose of this study was to analyze quantitatively the publications concerning the subject, outlining an overview for the new research field of lean communication. Aiming for a deeper understanding, the concepts of lean information were applied in a real process. The quantitative analysis was carried out to find the main authors and works, as well as the main terms used in related works. We used the methods of citations works, co-citation references, and co-occurrence of words using the VOSviewer software. This software was primarily designed to analyze bibliometric networks in order to create, visualize, and assess maps based on network data generated from queries in journals. We found a lack of a methodology for the development and implementation of lean information concepts. We observed a gap which had not been addressed yet, that is, mapping communication flows and developing and implementing lean information. Moreover, there was no method for improvement, implementation, and control.     

基于短时交通流量预测对路网微观交通仿真的研究

针对早高峰短时交通流量预测数据少、波动大的特点,提出用灰色模型进行预测。将灰色GM(2,1)改进为灰色GM(2,1,λ,ρ)预测模型,以提高预测精度。针对粒子群算法(PSO)的早熟现象,将Logistic混沌搜索嵌入到PSO算法,应用混沌粒子群算法(CPSO)寻找灰色GM(2,1,λ,ρ)预测模型最优的参数λ和ρ。结合两者提出了基于CPSO–GM(2,1,λ,ρ)的早高峰短时交通流预测模型。利用VISSIM对研究路网进行微观交通仿真,通过VISSIM–Excel、VBA–Matlab平台实现了短时交通流量预测和路网微观交通仿真数据的交互,对集成交通控制系统的架构进行了方案设计。仿真结果表明,结合流量预测的路网优于固定信号配时下的路网仿真。     

液压系统中液流压力损失的相关分析

分析液压系统中压力损失产生的原因,液流压力损失与雷诺数的关系,局部压力损失在不同管道下的计算;影响液流压力损失的因素,减少液压系统中压力损失产生的相关方法。     

基于Petri网的工作流模型设计与实现

Petri网适合描述异步、并发事件驱动和资源共享的办公自动化工作流部分，使用Petri网进行过程建模可以显著地改进和优化业务流程，更好地实现业务流程控制。以物业办公中的工作联系单为例，进行了业务流程分析、Petri网建模，并给出了任务表和后续节点流向控制算法。