The impact of coronavirus pandemic (COVID-19) on education: The role of virtual and remote laboratories in education

To avoid the spread of the COVID-19 crisis, many countries worldwide have temporarily shut down their academic organizations. National and international closures affect over 91% of the education community of the world. E-learning is the only effective manner for educational institutions to coordinate the learning process during the global lockdown and quarantine period. Many educational institutions have instructed their students through remote learning technologies to face the effect of local closures and promote the continuity of the education process. This study examines the expected benefits of e-learning during the COVID-19 pandemic by providing a new model to investigate this issue using a survey collected from the students at Imam Abdulrahman Bin Faisal University. Partial Least Squares Structural Equation Modeling (PLS-SEM) was employed on 179 useable responses. This study applied Push-Pull-Mooring theory and examined how push, pull, and mooring variables impact learners to switch to virtual and remote educational laboratories. The Protection Motivation theory was employed to explain how the potential health risk and environmental threat can influence the expected benefits from e-learning services. The findings revealed that the push factor (environmental threat) is significantly related to perceived benefits. The pull factors (e-learning motivation, perceived information sharing, and social distancing) significantly impact learners' benefits. The mooring factor, namely perceived security, significantly impacts learners’ benefits.     

Validation of virtual reality as a tool to understand and prevent child pedestrian injury

In recent years, virtual reality has emerged as an innovative tool for health-related education and training. Among the many benefits of virtual reality is the opportunity for novice users to engage unsupervised in a safe environment when the real environment might be dangerous. Virtual environments are only useful for health-related research, however, if behavior in the virtual world validly matches behavior in the real world. This study was designed to test the validity of an immersive, interactive virtual pedestrian environment. A sample of 102 children and 74 adults was recruited to complete simulated road-crossings in both the virtual environment and the identical real environment. In both the child and adult samples, construct validity was demonstrated via significant correlations between behavior in the virtual and real worlds. Results also indicate construct validity through developmental differences in behavior; convergent validity by showing correlations between parent-reported child temperament and behavior in the virtual world; internal reliability of various measures of pedestrian safety in the virtual world; and face validity, as measured by users' self-reported perception of realism in the virtual world. We discuss issues of generalizability to other virtual environments, and the implications for application of virtual reality to understanding and preventing pediatric pedestrian injuries.     

基于Virtools的高级交互式虚拟现实模型库的建立

在产品的设计和展示中,虚拟现实模型可取代实物模型,达到节约成本、方便使用的目的。以虚拟现实引擎Virtools为平台,利用3DMax建立虚拟模型,导入到Virtools中建立虚拟模型库。讨论3DMax和Virtools的接口问题,并对虚拟模型进行了各种交互控制,进而形成了具有Virtools内嵌数据库支持的虚拟模型库。实现的高级交互控制虚拟模型库增加模型库的沉浸感,使虚拟现实技术更加实用。     

Integrating TTF and UTAUT2 theories to investigate the adoption of augmented reality technology in education: Perspective from a developing country

Augmented reality (AR) has gained increased recognition in varying fields, in particular educational contexts. In the wake of the Covid-19 pandemic, home-based learning becomes a reality and is already in place across the globe, and learning via augmented reality technology will help learners comprehend learning content in a more creative frame of mind than ever before. Very little research has examined the adoption behavior of augmented reality in developing country perspectives. Therefore, there is a pressing necessity to understand the dynamics of augmented reality adoption for the benefit of motivating and inspiring students to adopt this highly innovative and impactful type of technology in the learning process. Against this background, the authors proposed and tested a model based on integrating Task-Technology Fit (TTF) and UTUAT2 theories. The results reveal the positive effect of task technology fit, performance expectancy, effort expectancy, social influence, facilitating condition, and hedonic motivation on behavioral intention (BI) in the adoption process of augmented reality in educational settings, where price value is found to exert little influence on behavioral intention. This model explains 49% of the variance in intentional behavior to adopt AR technology in the educational context. The conclusions of this study will add to the literature more informative knowledge leading to increased awareness of the dynamics and behaviors of AR adoption in a developing country perspective. We present and discuss the theoretical contributions and practical implications of our findings.     

基于虚拟现实的截流施工动态可视化仿真研究

利用虚拟现实和3dsmax技术进行了截流施工场景三维仿真建模,并在此基础上,结合龙口水力指标的动态计算,提出了基于虚拟现实的截流施工三维动态可视化仿真技术,实现了截流过程的逼真预演和多方案的比较分析,从而为截流组织设计与决策提供了强有力的可视化分析手段。     

A grounded theory model for analysis of marine accidents

The purpose of this paper was to design a conceptual model for analysis of marine accidents. The model is grounded on large amounts of empirical data, i.e. the Swedish Maritime Administration database, which was thoroughly studied. This database contains marine accidents organized by ship and variable. The majority of variables are non-metric and some have never been analyzed because of the large number of values. Summary statistics were employed in the data analysis. In order to develop a conceptual model, the database variables were clustered into eleven main categories or constructs, which were organized according to their properties and connected with the path diagram of relationships. For demonstration purposes, one non-metric and five metric variables were selected, namely fatality, ship's properties (i.e. age, gross register tonnage, and length), number of people on board, and marine accidents. These were analyzed using the structural equation modeling (SEM) approach. The combined prediction power of the ‘ship's properties’ and ‘number of people on board’ independent variables accounted for 65% of the variance of the fatality. The model development was largely based on the data contained in the Swedish database. However, as this database shares a number of variables in common with other databases in the region and the world, the model presented in this paper could be applied to other datasets. The model has both theoretical and practical values. Recommendations for improvements in the database are also suggested.     

The virtual biomodel as a complementary resource for the diagnosis of mandibular ankylosis

Ankylosis of the mandibular joint is one of many pathologies that affect the temporomanbibular joint. It comprises the mandible condyle, the base of the skull bone and the joint itself, inducing changes in the skull bone and face complex, affecting their growth to different degrees, which can cause morphofunctional alterations. The objective of this paper is to show the gains of using a virtual biomodel as an additional resource in the diagnosis of mandibular joint ankylosis, besides the analysis of multiplanar slices.     

The use of the Novosol process for the treatment of polluted marine sediment

The work presented in this article concerns polluted marine sediments. The article is divided into three parts. The first part discusses existing industrial procedures of treatment. The second part introduces the Novosol((R)) process, which was used for the treatment of polluted marine sediments. This process is based on the stabilization of heavy metals in the solid matrix by phosphatation and the destruction of organic matter by calcination. Finally, after a comparison had been made between environmental results obtained on both polluted marine sediments and inert ones, treated sediments were introduced in the production of clay bricks. The results obtained show that the Novosol process leads to the immobilization of most heavy metals and can be considered as an efficient tool for the stabilisation of polluted marine sediment. Thus, the results of physical and mechanical tests as compressive strength and water absorption indicate that performances obtained were comparable to standard brick values. These results confirm that, once treated, polluted sediments can be recycled.     

The open hole tensile test: a challenge for virtual testing of composites

The open hole tension strength is an important parameter for composite structures since it is can be a limiting factor in design. It is also difficult to characterise and predict through analytical or numerical methods since there exists a wide variation in experimental results depending on testing configuration. Here a range of such variations are presented and the behaviour explained in terms of the development of sub-critical damage in the form of intra-ply splits and inter-ply delaminations and their interaction with each other and also with fibre failure. A finite element based numerical analysis technique has been developed and applied to each case in turn, successfully predicting the failure modes, trends and strengths. This is sufficiently robust to form the basis for a virtual testing framework for the open hole tensile strength of composite materials.     

Buying Time for an Effective Epidemic Response: The Impact of a Public Holiday for Outbreak Control on COVID-19 Epidemic Spread

Rapid responses in the early stage of a new epidemic are crucial in outbreak control. Public holidays for outbreak control could provide a critical time window for a rapid rollout of social distancing and other control measures at a large population scale. The objective of our study was to explore the impact of the timing and duration of outbreak-control holidays on the coronavirus disease 2019 (COVID-19) epidemic spread during the early stage in China. We developed a compartment model to simulate the dynamic transmission of COVID-19 in China starting from January 2020. We projected and compared epidemic trajectories with and without an outbreak-control holiday that started during the Chinese Lunar New Year. We considered multiple scenarios of the outbreak-control holiday with different durations and starting times, and under different assumptions about viral transmission rates. We estimated the delays in days to reach certain thresholds of infections under different scenarios. Our results show that the outbreak-control holiday in China likely stalled the spread of COVID-19 for several days. The base case outbreak-control holiday (21 d for Hubei Province and 10 d for all other provinces) delayed the time to reach 100 000 confirmed infections by 7.54 d. A longer outbreak-control holiday would have had stronger effects. A nationwide outbreak-control holiday of 21 d would have delayed the time to 100 000 confirmed infections by nearly 10 d. Furthermore, we find that outbreak-control holidays that start earlier in the course of a new epidemic are more effective in stalling epidemic spread than later holidays and that additional control measures during the holidays can boost the holiday effect. In conclusion, an outbreak-control holiday can likely effectively delay the transmission of epidemics that spread through social contacts. The temporary delay in the epidemic trajectory buys time, which scientists can use to discover transmission routes and identify effective public health interventions and which governments can use to build physical infrastructure, organize medical supplies, and deploy human resources for long-term epidemic mitigation and control efforts.     

School closures reduced social mixing of children during COVID-19 with implications for transmission risk and school reopening policies

School closures may reduce the size of social networks among children, potentially limiting infectious disease transmission. To estimate the impact of K–12 closures and reopening policies on children''s social interactions and COVID-19 incidence in California''s Bay Area, we collected data on children''s social contacts and assessed implications for transmission using an individual-based model. Elementary and Hispanic children had more contacts during closures than high school and non-Hispanic children, respectively. We estimated that spring 2020 closures of elementary schools averted 2167 cases in the Bay Area (95% CI: −985, 5572), fewer than middle (5884; 95% CI: 1478, 11.550), high school (8650; 95% CI: 3054, 15 940) and workplace (15 813; 95% CI: 9963, 22 617) closures. Under assumptions of moderate community transmission, we estimated that reopening for a four-month semester without any precautions will increase symptomatic illness among high school teachers (an additional 40.7% expected to experience symptomatic infection, 95% CI: 1.9, 61.1), middle school teachers (37.2%, 95% CI: 4.6, 58.1) and elementary school teachers (4.1%, 95% CI: −1.7, 12.0). However, we found that reopening policies for elementary schools that combine universal masking with classroom cohorts could result in few within-school transmissions, while high schools may require masking plus a staggered hybrid schedule. Stronger community interventions (e.g. remote work, social distancing) decreased the risk of within-school transmission across all measures studied, with the influence of community transmission minimized as the effectiveness of the within-school measures increased.     

The challenges of COVID-19 control policies for sustainable development of business: Evidence from service industries

Such large-scale disruptions as the pandemic increase the uncertainty and risk related to business. Therefore, the business continuity management (BCM) has become an essential technical solution for enterprise emergency response. Since the beginning of 2020, the COVID-19 has spread worldwide at an alarming rate causing many threats to sustainable development of the business sector. The decline in consumer demand has hugely impacted service industries, such as wholesale and retail sales, tourism. Enterprise production and operations have faced severe challenges. In this study, we develop a risk factor analysis of BCM under the presence of COVID-19 in China. Based on a statistical survey of 940 enterprises in Hangzhou City, China, this study employs ordinal logistic regression to explore the hindering effect of risk factors introduced by the epidemic on business performance. Then, the interpretive structure model (ISM) is applied to analyze the hierarchical structure of the factors under examination. The key factors influencing the enterprise production and operation during COVID-19 outbreak significantly differ across the sub-sectors of the service industry. Therefore, this paper assesses the resilience of the productive technologies and business models of different industries amid the pandemic. This paper proposes epidemic prevention and control strategy focusing on investment and government regulation to ensure sustainable business development.     

The influence of heat treatment on low frequency fatigue crack growth rates for a marine steel tested in air and seawater

A quenched and tempered marine steel has been cooled at different rates after tempering and low frequency fatigue crack growth rates in air and seawater compared. Water quenching was shown to result in significantly lower fatigue crack growth rates compared to furnace cooling. The likely causes and the implications of the results are discussed.