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181.
Roberto Truzoli Veronica Pirola Stella Conte 《Journal of Computer Assisted Learning》2021,37(4):940-952
The lockdown due to COVID-19 in Italy resulted in the sudden closure of schools, with a shift from traditional teaching to the online one. Through an online questionnaire, this survey explores teachers' experience of online teaching, the level of risk factors (e.g., stress) and protective factors (e.g., locus of control) and their impact on satisfaction levels during the social distancing. One hundred seven high school teachers from Lombardy, an Italian region very affected by the COVID-19 outbreak, participated. Results show that depression and stress are the main predictors of satisfaction levels for online teaching. In addition, coping, locus of control and self-efficacy emerge as important protective factors. Finally, although there is great satisfaction with the online teaching experience, critical elements emerged. This study is relevant because it describes the critical elements of the online teaching experience, and identifies some protective factors and the main risk factors in teachers operating in an area strongly marked by social restrictions imposed by the pandemic. High school teachers emerge as a sub-group of the general population with specific psychological reactions. Considering the results, it is possible to suggest providing high-quality educational support and crisis-psychological oriented services to teachers, and help to maintain the psychological well-being. 相似文献
182.
Cyberattacks are difficult to prevent because the targeted companies and organizations are often relying on new and fundamentally insecure cloud-based technologies, such as the Internet of Things. With increasing industry adoption and migration of traditional computing services to the cloud, one of the main challenges in cybersecurity is to provide mechanisms to secure these technologies. This work proposes a Data Security Framework for cloud computing services (CCS) that evaluates and improves CCS data security from a software engineering perspective by evaluating the levels of security within the cloud computing paradigm using engineering methods and techniques applied to CCS. This framework is developed by means of a methodology based on a heuristic theory that incorporates knowledge generated by existing works as well as the experience of their implementation. The paper presents the design details of the framework, which consists of three stages: identification of data security requirements, management of data security risks and evaluation of data security performance in CCS. 相似文献
183.
Computer networks face a variety of cyberattacks. Most network attacks are contagious and destructive, and these types of attacks can be harmful to society and computer network security. Security evaluation is an effective method to solve network security problems. For accurate assessment of the vulnerabilities of computer networks, this paper proposes a network security risk assessment method based on a Bayesian network attack graph (B_NAG) model. First, a new resource attack graph (RAG) and the algorithm E-Loop, which is applied to eliminate loops in the B_NAG, are proposed. Second, to distinguish the confusing relationships between nodes of the attack graph in the conversion process, a related algorithm is proposed to generate the B_NAG model. Finally, to analyze the reachability of paths in B_NAG, the measuring indexs such as node attack complexity and node state transition are defined, and an iterative algorithm for obtaining the probability of reaching the target node is presented. On this basis, the posterior probability of related nodes can be calculated. A simulation environment is set up to evaluate the effectiveness of the B_NAG model. The experimental results indicate that the B_NAG model is realistic and effective in evaluating vulnerabilities of computer networks and can accurately highlight the degree of vulnerability in a chaotic relationship. 相似文献
184.
Samar Shetaban Mir Mehdi Seyyed Esfahani Abbas Saghaei Abbas Ahmadi 《Computational Intelligence》2021,37(1):435-460
Today, air pollution, smoking, use of fatty acids and ready‐made foods, and so on, have exacerbated heart disease. Therefore, controlling the risk of such diseases can prevent or reduce their incidence. The present study aimed at developing an integrated methodology including Markov decision processes (MDP) and genetic algorithm (GA) to control the risk of cardiovascular disease in patients with hypertension and type 1 diabetes. First, the efficiency of GA is evaluated against Grey Wolf optimization (GWO) algorithm, and then, the superiority of GA is revealed. Next, the MDP is employed to estimate the risk of cardiovascular disease. For this purpose, model inputs are first determined using a validated micro‐simulation model for screening cardiovascular disease developed at Tehran University of Medical Sciences, Iran by GA. The model input factors are then defined accordingly and using these inputs, three risk estimation models are identified. The results of these models support WHO guidelines that provide medicine with a high discount to patients with high expected LYs. To develop the MDP methodology, policies should be adopted that work well despite the difference between the risk model and the actual risk. Finally, a sensitivity analysis is conducted to study the behavior of the total medication cost against the changes of parameters. 相似文献
185.
通过调研焊接车间锅炉筒节匹配现状,发现目前的方法是根据工人的经验测量几个点进行匹配。这样的匹配方法不仅不够精确,并且不利于追溯匹配记录。因此,提出锅炉筒节匹配算法的系统设计和实现方法。系统使用激光测距仪代替人工测量,用优化匹配算法代替传统的根据工人经验进行匹配的方法,使筒节匹配过程更精确。首先,利用激光测距仪代替人工测量获得筒节端面8个点的直径值。然后,结合软件循环匹配、排序、寻求最小值等算法,找到最适合焊接一起的筒节以及焊接角度。最后,完成系统功能设计,开发控制软件。焊接车间的实际应用表明,该系统更精确地进行筒节匹配,避免工人测量误差和经验不足造成匹配错误返工现象。该系统可运用在各种管道焊接中,对推动智能控制技术在工业过程中的实际应用有借鉴意义。 相似文献
186.
187.
随着信息化进程的快速发展,保障信息系统的安全性和降低信息系统潜在的风险,一直是国内外学者关注的焦点,而风险评估正是解决该问题的有效方法之一,但是在风险评估过程中存在评估指标难以量化、风险值难以界定等困难,因此文章提出了一种基于灰色关联分析的信息安全风险评估方法,该方法首先建立了信息系统的风险评估指标体系,其次将评估的信息系统与最优信息系统进行关联度分析,最后得出信息系统风险的准确度量。该方法可以使信息系统的评估过程简单化,标准化。 相似文献
188.
189.
韩起云 《计算机测量与控制》2012,20(9):2473-2476
针对云计算环境下网络信息系统会面临更多安全风险问题,总结出8种威胁安全准则,并对应得到影响因素;结合云计算技术具有协作性、虚拟性等特点,采用层次分析法并引入相关系数对多决策目标进行分析,提出一种基于云环境下的信息安全风险评估模型;最后运用该模型建模得出云计算环境下的信息系统安全风险评估思路;实验结果表明文章提出的风险评估模型具有一定的实际应用价值。 相似文献
190.
空中交通预警与防撞系统(TCAS)风险及对策研究 总被引:1,自引:0,他引:1
空中交通预警与防撞系统TCAS对飞行安全非常重要,它能够通过对附近的飞机进行冲突检测,预测未来可能发生的危险,提示飞行员避免危险,帮助机组维持与其他飞机之间的空中交通安全间隔;但TCAS本身依然存在风险;在此对TCAS进行了半物理仿真测试,包括数字样机开发测试、物理样机开发测试、虚拟试飞以及数据统计分析等,对其各项功能进行测试与验证;在参阅众多相关文献的基础上,结合所做的研究工作,讨论了TCAS的主要风险,并针对这些风险,提出TCAS在设计、测试、操作方面需要改进的地方,从各方面完善TCAS,降低其风险,进一步保障飞行安全。 相似文献