智能机器人机械臂动态可靠性粗糙-模糊综合评价研究

研究目的旨在建立智能机器人机械臂总体动态可靠性的评价方法,根据智能机器人机械臂各运动参数的概率信息,利用模糊方法,确定单因素的隶属度函数,按照运动参数可靠度进行单因素模糊评价,得到不同构件的可靠度评价;然后根据粗糙集理论判断各个构件对机械臂总体可靠性的影响,对概率信息进行约简;再根据不同构件的可靠度进行多因素模糊综合评价,得到整个智能机器人机械臂的总体可靠度的评价。通过算例证明该方法对复杂智能机器人机械臂总体可靠性评价是有效可行的。     

基于Packet Tracer环境下的网络课程考核平台构建

借助仿真软件进行教学是目前许多院校在讲授网络课程时普遍采用的一种教学方式,Packet Tracer就是众多仿真软件中的一种,因其图符化的操作界面及配置上的高仿真性被普遍采用。然而从整个教育环节来看,除了常规的教师的教平台、学生的学平台,还需要有对于知识掌握程度进行测试的考核平台,而PacketTracer在此方面则存在一些不足。本文在探讨网络课程考核平台功能需求的基础上,提出如何利用其已有功能进行二次开发的系统架构方案以及该考核平台实现的多项核心技术。     

一种应用主机访问图的网络漏洞评估模型

针对基于攻击图的风险评估的可扩展性问题,从内部安全威胁的角度,提出一种基于主机访问图的漏洞评估的定量方法.首先引入网络访问关系与主机关键度的概念,并提出主机安全威胁模型,接着通过生成主机访问图得到所有主机之间的网络访问关系,在此基础上计算各个漏洞对整个网络安全威胁产生的影响,从而实现对漏洞的评估与排序.实验表明该方法能够有效地评估网络的安全状态和漏洞在网络中的严重程度,并为加强网络安全提供重要依据.     

扩展角色表达能力的描述逻辑

针对角色描述能力较弱的问题,在现有描述逻辑SHIQ中增加角色表达式对角色进行描述,形成描述逻辑SHIQb。给出SHIQb的相关定义,并证明若SHIQb知识库中所有角色表达式都是安全的,那么该知识库在现有的推理机KAON2上的推理仍然是Polynomia Time这一定理。在此基础上,提出一种能够判断角色表达式是否安全的算法。     

基于SVM和GA的图像质量评价方法

针对主观评价关联方法易陷入局部最优以及处理非线性、高维、小样本问题时效果不佳等问题,以均方误差、峰值信噪比、奇异值分解这3个图像质量客观评价指标和LIVE数据库评分作为学习样本,通过支持向量机学习得到主客观关联函数,利用遗传算法进行最优参数选取,由此得到具有主客观一致性的评价模型。测试结果表明,相比传统方法,该方法对图像质量的评价更准确。     

基于WinCC的整备作业安全监控系统

为实现电力机车整备作业安全监控自动化,结合整备作业现场控制要求,提出基于视窗控制中心(WinCC)组态软件的电力机车整备作业安全监控系统。采用组态软件的模块化设计方法,利用网络通信、监控和现场总线技术,实现以WinCC为平台的人机界面和以S7-300PLC为主站、S7-200PLC为从站的PROFIBUS-DP总线网络控制系统。测试结果表明,该系统可实现多股道同时作业,并实时实现三级分层间的数据交换。     

基于CUDA的3G视频清晰度评估方法

针对传统视频清晰度评估方法实时性较差的问题,利用统一计算架构(CUDA)高度并行性的特点,提出一种基于CUDA的3G视频清晰度评估方法。实验结果表明,与传统的视频清晰度评估方法相比,该方法能在保证准确评估视频清晰度的同时缩短算法的执行时间,计算速度约是传统串行算法的30倍。     

ARCE风险处理计划测量模型的设计与实现

提出用于定量测量风险处理计划有效性的ARCE模型,从理论上证明该模型的正确性.以组织信息安全资产的风险值和已实施控制措施为输入,通过中间变量矩阵得到风险处理计划有效性矩阵的模型量化指标体系.模型实现过程包括风险评估、风险处理、定量测量、安全事件管理和报表5个部分,并给出实施流程.应用结果表明,该模型能准确测量风险处理计...     

Thermodynamic assessment of the La-Mg system

A thermodynamic modeling and optimization of the La-Mg system is carried out by means of the CALPHAD method taking into account the latest experimental results. The liquid, bcc-La, fcc-La, dhcp-La and hcp-Mg solutions are modeled as substitutional solutions (La, Mg) using the Redlich-Kister formalism. The LaMg, LaMg₂, La₅Mg₄₁, La₂Mg₁₇ and LaMg₁₂ phases are treated as stoichiometric compounds, and the non-stoichiometry of LaMg₃ is described as (La,Mg)_0.25Mg_0.75. The results are in good agreement with the set of experimental data which were carefully discussed and selected.     

Online formative assessment in higher education: A review of the literature

As online and blended learning has become common place educational strategy in higher education, educators need to reconceptualise fundamental issues of teaching, learning and assessment in non traditional spaces. These issues include concepts such as validity and reliability of assessment in online environments in relation to serving the intended purposes, as well as understanding how formative assessment functions within online and blended learning. This article provides a systematic qualitative review of the research literature on online formative assessment in higher education. As an integrative narrative review, the method applied in this review entailed systematic searching, reviewing, and writing this review of the literature to bring together key themes and findings of research in this field. The authors applied qualitative thematic criteria in selecting and reviewing the available literature from which they focused on identifying and analyzing the core themes that are central to the concept of formative assessment with a key focus on application of formative assessment within blended and online contexts. Various techniques were identified for formative assessment by the individual, peers and the teacher, many of which were linked with online tools such as self-test quiz tools, discussion forums and e-portfolios. The benefits identified include improvement of learner engagement and centrality in the process as key actors, including the development of a learning community. The key findings are that effective online formative assessment can foster a learner and assessment centered focus through formative feedback and enhanced learner engagement with valuable learning experiences. Ongoing authentic assessment activities and interactive formative feedback were identified as important characteristics that can address threats to validity and reliability within the context of online formative assessment.