A simple dilution model of the expired jet

Short-range exposure to expired aerosols or droplet nuclei has been considered as the predominant route for SARS-CoV-2. The observed effect of mask wearing, and social distancing suggests the importance of expired jet in the spread of COVID-19. The well-known steady-state dilution model is no longer valid for the interrupted expiratory jet. We reanalysed the existing interrupted jet data and proposed a simple dilution model of expired jet using the two-stage jet model. The interrupted jet consists of two stages, i.e., the jet-like and puff-like stage. Results show dilution factor grows linearly with the distance at the jet-like stage but increases with the cubic of the increasing distance in the puff-like stage. Dilution factor at any distance for the puff-like stage decreases as the activity intensifies, which is still much larger than that estimated via the steady jet model. The findings can be further applied into the short-range airborne exposure assessment. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

Social linking practices across physical distance: The material constitution of sociality

The COVID-19 crisis has resulted in physical distancing regulations, disrupting traditional practices of establishing and maintaining social relationships. We draw attention to digital nomadism as a mature case of navigating sociality in uncertainty to investigate how the linking value of materiality establishes social proximity without geographic contiguity through physical, virtual, and imagined practices. Using Miller's (1987) theory of materiality and triangulating data collected from in-depth interviews and netnography, this study details the material constitution of co-presence with others in physical distance. We propose that consumers oscillate between work—instrumental practices of signaling and curating—and play—emotional practices of belonging and indulging—to experience social linking across different spatial and temporal frameworks.

Will Social Distancing in Service Encounters Affect Consumers' Value Perception During the COVID-19 Pandemic? The Role of Servicescape, Self-Efficacy, and Technological Intervention

This study investigates how physical and psychological distance from one's surroundings may influence one's perception of connectedness with the servicescape and, ultimately, perception of value. It also examines the effect of consumers' techno-psychological differences and interaction modes on this distance–closeness relationship. The researchers develop and test a conceptual framework of how personal cognitive traits and technological intervention may alter consumers' perceived connectedness to the servicescape and influence their perceived value in different service settings. Via a quasi-experiment design in three service scenarios, this research shows a synthetical effect of contactless technology in the distancing setting that may work more effectively on high self-efficiency customers to change their perceived closeness to the servicescape and further change their evaluation of the service. The findings reveal the practical implications of social distancing for different types of consumers in service encounters during or after the COVID-19 pandemic. © The Author(s) 2023.

Cognitive Cameras on the Edge for Crowd Physical Distancing Monitoring in the Covid-19 Era.

With the rise of the Internet of Things (IoT) architectures and protocols, new video analytics systems and surveillance applications have been developed. In conventional systems, all the streams produced by cameras are sent to a centralized node where they can be seen by human operators whose task is to identify uncommon on abnormal situations. However, this way, much bandwidth is necessary for the system to work, and the number of necessary resources is proportional to the number of cameras and streams involved. In this paper, we propose an interesting approach to this problem: transforming any IP camera into a cognitive object. A cognitive camera (CC) can be considered a classic connected camera with onboard computational power for intelligent video processing. A CC can understand and interact with the surroundings, intelligently analyze complex scenes, and interact with the users. The IoT Edge Computing approach decreases latency in the decision-making process and consumes a tiny portion of bandwidth concerning the stream of a video, even in low resolution. CCs can help to address COVID-19. As a preventive measure, proper crowd monitoring and management systems must be installed in public places to limit sudden outbreaks and improve healthcare. The number of new infections can be significantly reduced by adopting physical distancing measures earlier. Motivated by this notion, a real-time crowd monitoring and management system for physical distance classification using CCs is proposed in this research paper. The experiment on Movidius board, an AI accelerator device, provides promising results of our proposed method in which the accuracies can achieve more than 85% from different datasets.

Persuasive Messages for Improving Adherence to COVID-19 Prevention Behaviors: Randomized Online Experiment.

BACKGROUND: Adherence to nonpharmaceutical interventions for COVID-19, including physical distancing, masking, staying home while sick, and avoiding crowded indoor spaces, remains critical for limiting the spread of COVID-19. OBJECTIVE: The aim of this study was to test the effectiveness of using various persuasive appeals (deontological moral frame, empathy, identifiable victim, goal proximity, and reciprocity) at improving intentions to adhere to prevention behaviors. METHODS: A randomized online experiment using a representative sample of adult Canadian residents with respect to age, ethnicity, and province of residence was performed from March 3 to March 6, 2021. Participants indicated their intentions to follow public health guidelines, saw one of six flyers featuring a persuasive appeal or no appeal, and then rated their intentions a second time. Known correlates of attitudes toward public health measures were also measured. RESULTS: Intentions to adhere to public health measures increased in all appeal conditions. The message featuring an empathy appeal resulted in a greater increase in intentions than the control (no appeal) message. Moreover, the effectiveness of persuasive appeals was moderated by baseline intentions. Deontological, empathy, identifiable victim, and reciprocity appeals improved intentions more than the control message, but only for people with lower baseline intentions to adhere to nonpharmaceutical interventions. CONCLUSIONS: Public health marketing campaigns aiming to increase adherence to COVID-19 protective behaviors could achieve modest gains by employing a range of persuasive appeals. However, to maximize impact, it is important that these campaigns be targeted to the right individuals. TRIAL REGISTRATION: ClinicalTrials.gov NCT05722106; https://clinicaltrials.gov/ct2/show/NCT05722106.

Patterns and predictors of adherence to health-protective measures during COVID-19 pandemic in the UK: cross-sectional and longitudinal findings from the HEBECO study.

BACKGROUND: Adherence to health-protective behaviours (regularly washing hands, wearing masks indoors, maintaining physical distancing, carrying disinfectant) remains paramount for the successful control of COVID-19 at population level. It is therefore important to monitor adherence and to identify factors associated with it. This study assessed: 1) rates of adherence, to key COVID-19 health-protective behaviours and 2) the socio-demographic, health and COVID-19-related factors associated with adherence. METHODS: Data were collected on a sample of UK-based adults during August-September 2020 (n = 1,969; lockdown restrictions were eased in the UK; period 1) and November 2020- January 2021 (n = 1944; second UK lockdown; period 2). RESULTS: Adherence ranged between 50-95%, with higher adherence during the period of stricter measures. Highest adherence was observed for wearing masks indoors (period 1: 80.2%, 95%CI 78.4%-82.0%, period 2: 92.4%, 95%CI 91.1%-93.6%) and lowest for carrying own disinfectant (period 1: 48.4%, 95%CI 46.2%-50.7%, period 2: 50.7%, 95%CI 48.4%-53.0%). Generalized estimating equation models indicated that key factors of greater odds of adherence included being female, older age, having higher income, residing in England, living with vulnerable individuals and perceived high risk of COVID-19. CONCLUSIONS: Targeted messages to different demographic groups may enhance adherence to health-protective behaviours, which is paramount for the control of airborne respiratory diseases. PROTOCOL AND ANALYSIS PLAN REGISTRATION: The analysis plan was pre-registered, and it is available at https://osf.io/6tnc9/ .

THE COVID-19 PANDEMIC AND PUBLIC SPACES: AN EVALUATION OF PUBLIC SPACE QUALITY FOR PROVIDING A HEALTHY ENVIRONMENT DURING AND POST-THE COVID-19 PANDEMIC IN RIYADH PARKS

We are currently in the midst of unprecedented restrictions in the use of public spaces worldwide Because of COVID-19 pandemics, this invites us to rethink about public spaces in. This research study evaluated the ability of open public spaces to provide a healthy environment for users after COVID-19 pandemic by five dimensions Including use and user, accessibility, amenities and furniture, comfort and safety, and green environment in general as well during the COVID-19 pandemic in addition to evaluate the Physical procedures taken by the authorities responsible for managing these places to reducing the risk of exposure to COVID-19 disease. Four open public space were analysed in different locations in Riyadh parks, this research presented a set of recommendations for urban designers, urban planning and the authorities concerned in Riyadh parks to re-advance the open public space in Riyadh parks to be more comfortable, healthier and flexible during and post the COVID-19 pandemic. © School of Engineering, Taylor's University.

Fear of COVID-19 and Prevention Behaviors: Cross-Lagged Panel Analysis.

BACKGROUND: The ongoing COVID-19 pandemic has brought forth conversations about effective behavior change models for increasing prevention behavior, ranging from wearing masks in public to physical distancing. Among the considered behavior change techniques is the use of fear appeals, through which a negative possible outcome is emphasized to invoke fear, which in turn may promote prevention behaviors to counter the likelihood of the negative outcome. Although fear is hypothesized as health promoting in some theories of health behavior, little research has rigorously assessed the relationship. OBJECTIVE: In our exploratory analyses, we aim to examine the association, including directionality of the association between fear of COVID-19 and COVID-19 prevention behaviors across 2 time points during the early COVID-19 pandemic among a sample of US women. METHODS: The COPE study, a web-based survey of US women's COVID-19 experiences, was deployed in May-June 2020 (time 1) with follow-up in December 2020-January 2021 (time 2; n=200). Demographic characteristics as well as fear of COVID-19 and COVID-19 prevention behaviors (eg, staying home except for essential activities, physical distancing in public, and masking in public) were measured. Descriptive and bivariate analyses were used to characterize COVID-19 prevention behaviors and fear of COVID-19 among participants. Cross-lagged panel analysis, a type of structural equation modeling that assesses directionality of temporal associations, was used to understand relationships, if any, between variables of interest. RESULTS: We found cross-sectional associations between fear of COVID-19 and staying home and physical distancing, as well as temporal associations between fear at time 1 and time 2 and prevention behaviors at time 1 and time 2. However, results of the cross-lagged panel analysis indicated no cross-lagged temporal relationships between fear of COVID-19 and COVID-19 prevention behaviors 6 months apart. CONCLUSIONS: Fear of COVID-19 did not appear to predict COVID-19 prevention behaviors 6 months after initial measurements among the sample of women recruited for our study. Future research should rigorously test these associations longitudinally, and alternative methods of public health prevention promotion should be considered.

Immersive robotic telepresence system to support a person with intellectual and motor disabilities perform a daily task: a case study

Purpose In this proof-of-concept study, the authors assessed the feasibility of using a humanoid robot controlled remotely via an immersive telepresence system to support a person with intellectual and motor disabilities performing a daily task (i.e. setting a table for lunch). Design/methodology/approach The system involved a head-mounted display and two joysticks. A teleoperator was able to see through the video cameras of the robot and deliver the instructions verbally to the participant located in a different room. To assess the system, a baseline phase (A) was followed by an intervention (i.e. tele-operated support) phase (B) and a return to a baseline phase (A). Findings Data showed a marked increase in the average frequency of task steps correctly performed from baseline (M = 15%) to intervention (M = 93%). Accuracy reached 100% in the return to baseline. Originality/value These preliminary findings, along with qualitative feedback from users, suggest that an immersive telepresence system may be used to provide remote support to people with intellectual and motor disabilities.

Affective Attitudes in the Face of the COVID-19 Pandemic: The Dynamics of Negative Emotions and a Sense of Threat in Poles in the First Wave of the Pandemic.

For millions of people, the COVID-19 pandemic situation and its accompanying restrictions have been a source of threat and confrontation with negative emotions. The pandemic's universal and long-term character, as well as the ensuing drastic limitation of control over one's life, have made it necessary to work out adaptive strategies that would reduce negative experiences and eventually lead to the restoration of well-being. The aim of this research was to identify strategies that people use in response to a long-term threat that restore affective balance and a subjective sense of security. We registered selected manifestations of affective reactions to the pandemic situation. The researchers focused on the dynamics of changes in the areas of (1) experienced negative emotions (asked in an indirect way) and (2) a subjective feeling of threat regarding the pandemic (in three different contexts: Poland, Europe, and worldwide) during the first phase of the pandemic in Poland. It was expected that both the negative emotions and the sense of threat would decrease with time. In addition, it was anticipated that the physical distance would modify the assessment of the situation as threatening depending on the geographical proximity: in Poland, Europe, and worldwide. We used the mixed quasi-experimental design in the series of four studies conducted by Internet in March, May, June, and July 2020. The intensity of negative emotions and the sense of threat caused by the pandemic situation in Poland, Europe, and worldwide were measured. Despite the objective number of confirmed COVID-19 cases during each of the stages of the study, both the intensity of emotions attributed by participants as well as the feeling of threat were found to have decreased. In addition, surprisingly, a reversed effect of the distance was revealed: namely, a sense of threat experienced towards distant locations (Europe and the world) was found to be more acute when compared with the threat experienced in Poland. The obtained results are interpreted as a manifestation of adaptive perception of the threat that lies beyond one's control, which takes the form of unconscious, biased distortions: unrealistic optimism. The decrease in the intensity of negative emotions explains unrealistic absolute optimism, while the perception of the situation in Poland as less threatening than in Europe and around the world is predicted by unrealistic comparative optimism.

Prerequisite for COVID-19 Prediction: A Review on Factors Affecting the Infection Rate.

Since the year 2020, coronavirus disease 2019 (COVID-19) has emerged as the dominant topic of discussion in the public and research domains. Intensive research has been carried out on several aspects of COVID-19, including vaccines, its transmission mechanism, detection of COVID-19 infection, and its infection rate and factors. The awareness of the public related to the COVID-19 infection factors enables the public to adhere to the standard operating procedures, while a full elucidation on the correlation of different factors to the infection rate facilitates effective measures to minimize the risk of COVID-19 infection by policy makers and enforcers. Hence, this paper aims to provide a comprehensive and analytical review of different factors affecting the COVID-19 infection rate. Furthermore, this review analyses factors which directly and indirectly affect the COVID-19 infection risk, such as physical distance, ventilation, face masks, meteorological factor, socioeconomic factor, vaccination, host factor, SARS-CoV-2 variants, and the availability of COVID-19 testing. Critical analysis was performed for the different factors by providing quantitative and qualitative studies. Lastly, the challenges of correlating each infection risk factor to the predicted risk of COVID-19 infection are discussed, and recommendations for further research works and interventions are outlined.

Exposure and respiratory infection risk via the short-range airborne route.

Leading health authorities have suggested short-range airborne transmission as a major route of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, there is no simple method to assess the short-range airborne infection risk or identify its governing parameters. We proposed a short-range airborne infection risk assessment model based on the continuum model and two-stage jet model. The effects of ventilation, physical distance and activity intensity on the short-range airborne exposure were studied systematically. The results suggested that increasing physical distance and ventilation reduced short-range airborne exposure and infection risk. However, a diminishing return phenomenon was observed when the ventilation rate or physical distance was beyond a certain threshold. When the infectious quantum concentration was less than 1 quantum/L at the mouth, our newly defined threshold distance and threshold ventilation rate were independent of quantum concentration. We estimated threshold distances of 0.59, 1.1, 1.7 and 2.6 m for sedentary/passive, light, moderate and intense activities, respectively. At these distances, the threshold ventilation was estimated to be 8, 20, 43, and 83 L/s per person, respectively. The findings show that both physical distancing and adequate ventilation are essential for minimising infection risk, especially in high-intensity activity or densely populated spaces.

Intelligent agent model for simulating pedestrian traffic at urban trade fairs during the COVID-19 pandemic

The COVID-19 pandemic highlighted the need for new approaches to the urban environment. Among them, physical distancing is intended to minimize contagion and safeguard general welfare. In the present research, a simulated model was designed to identify close contacts during pedestrian traffic in specific urban activities such as a trade fair. This research type was applied and of quasi-experimental design, a parametric simulation model based on intelligent agents was developed at the micro level in urban trade fair scenarios. initially, theoretical trade fair configurations were compared, considering the shape of the walkable space and the arrangement of trade stands. Then, a manipulation of particular parameters is performed, among them, the probability of making a stall visible and the probability of stopping in case of direct contact or collision. Finally, the results were compared using statistical correlations, the PerMANOVA test, Games-Howell and the graphical analysis of the micro-simulated pedestrian behaviors by the developed model. It is concluded that the model is valid for theoretical pedestrian traffic models for the five simulated urban fairground scenarios.

A new system to detect coronavirus social distance violation

In this paper, a novel solution to avoid new infections is presented. Instead of tracing users’ locations, the presence of individuals is detected by analysing the voices, and people’s faces are detected by the camera. To do this, two different Android applications were implemented. The first one uses the camera to detect people’s faces whenever the user answers or performs a phone call. Firebase Platform will be used to detect faces captured by the camera and determine its size and estimate their distance to the phone terminal. The second application uses voice biometrics to differentiate the users’ voice from unknown speakers and creates a neural network model based on 5 samples of the user’s voice. This feature will only be activated whenever the user is surfing the Internet or using other applications to prevent undesired contacts. Currently, the patient’s tracking is performed by geolocation or by using Bluetooth connection. Although face detection and voice recognition are existing methods, this paper aims to use them and integrate both in a single device. Our application cannot violate privacy since it does not save the data used to carry out the detection and does not associate this data to people.

Physical Distancing Analytics for Construction Planning Using 4D BIM

The COVID-19 pandemic has impacted how the construction industry operates around the world. To fight the risk of transmission, new health, safety, and environmental (HSE) protocols have been put in place. Among these protocols are social distancing and limiting the number of workers per area, where social distancing acts as a so-called protective bubble for each worker. Contractors are now required to attempt to achieve (and be prepared to keep) social distancing among their workers whenever needed and possible. Otherwise, they could be forced to halt operations due to having an unsafe environment. Accordingly, construction plans, and corresponding workspace assignments, should be revised in a four-dimensional (4D) environment to ensure fulfillment. Even after the end of this pandemic, the new HSE awareness achieved during this experiment is expected to reshape the so-called new normal of construction. Therefore, this paper presents a novel workspace simulation and management solution comprising a theoretical framework and a semiautomated tool to incorporate physical distancing during 4D planning. The semiautomated tool creates a 4D building information model, loaded with workspaces and social distance bubbles as stochastic variables, and utilizes Monte Carlo simulation to model uncertainties occurring onsite. The uncertainties considered are both temporal and spatial, i.e., changes in productivity and workspace sizes, respectively. This tool surpasses existing workspace management solutions in that (1) it has a schedule generation module to recompute schedule projections based on temporal uncertainties, (2) its workspace generation module can automatically create physical distance buffers around selected workspaces, as per site conditions, (3) its 4D simulation can realistically mimic the work progress on the site, and (4) its 4D clash detection module can smartly detect and report both soft and hard operational clashes. Additionally, the proposed analytics target three levels of clash resolution: site, workspace, and activity level. The framework and developed tool were tested against a residential building case study. Over the course of 155 days, 26 activities with 257 workspace assignments were examined. The proposed solution was able to capture the critical schedule duration (21 out of 155 days), the impactful 4D clashes (44 out of 2,900), and the activities involved in the most sever clashes (5 out of 26). Hence, the proposed method and the developed software tool will help planners/construction managers understand the space requirements for construction operations considering social distancing and other required safety buffering, identify critical spatiotemporal zones, and suggest resolution strategies for the resulting clashes based on the analytics. © 2022 American Society of Civil Engineers.

VIRTUALIZED TEACHING PRACTICE IN GOOGLE CLASSROOM DURING REMOTE TEACHING: DIFFICULTIES AND OVERCOMING

This research aims to identify the main difficulties faced by teachers, given the virtualized teaching practice in the Google Classroom, during remote classes. In this context, remote education has stood out as an educational alternative for study studies during social withdrawal, caused by the pandemic of Covid-19 (New Coronavirus), affecting the practices that affect secondary education in the country. This is a descriptive qualitative research. As a tool for data production, run a semi-structured application that was made available through Google Forms. The collaborators were ten teachers who worked in a public school in Jeremoabo/BA. The study pointed out how the results of the greatest difficulty of the current period stem from changing habits and technological appropriation and the choice, by Google Classroom, was made using the need for digital inclusion practices. In this sense, the documents are being challenged to include technologies in teaching, even with difficulties, lack of resources and specific training to contemplate the use, in addition to the availability of digital resources and internet access by students.

The Impact of Physical Distancing on the Evacuation of Crowds

One of the key implications of COVID-19 is the adoption of physical distancing provisions to minimise the risk of virus transmission. Physical distancing can have significant consequences on crowd movement both in normal conditions and during emergencies. The impact of physical distancing is discussed in this chapter by first presenting an overview of its implications on crowd dynamics and space usage. This is followed by an assessment of expected changes in crowd behaviour, including changes in the fundamental walking speed/density and flow/density relationships. Findings from an experiment investigating the impact of physical distancing on flow rates through doors are presented. In addition, a set of recommendations concerning modifications of the hand calculations currently used for evacuation design (e.g. hydraulic models) are presented alongside a discussion on possible modifications to agent-based crowd models. A verification test to evaluate the results produced by crowd evacuation modelling tools considering physical distancing is also presented. This chapter highlights the importance of considering the increased movement time due to physical distancing in evacuation design and provides insights on how to account for this issue in crowd modelling. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Gapeau: Enhancing the Sense of Distance to Others with a Head-Mounted Sensor

Human perception lacks the capabilities to accurately assess distance. The recent Covid-19 pandemic outbreak rendered this ability particularly important. Augmenting our sense of distance can help maintain safe separation from others when required. To explore how systems can help users maintain physical distance, we designed, implemented and evaluated Gapeau - a head-mounted system for augmenting the sense of distance. Our system uses proximity sensors and thermal sensing to detect and measure the distance to other people. We conducted a validation protocol, an experiment, in which we compared different feedback modalities, and an in-the-wild study to evaluate Gapeau's performance and suitability for use in social contexts. We found that our system enabled users to more accurately determine whether they were maintaining a safe distance from others. Vibration and auditory feedback were found most effective and usable. Gapeau was perceived as socially acceptable. Our work contributes insights for augmented sensing systems with social relevance. © 2022 ACM.

Adherence to non-pharmacological preventive measures among healthcare workers in a middle-income country during the first year of the COVID-19 pandemic: Hospital and community setting.

This study assessed, using a self-reported questionnaire, the adherence to PPE (mask, gowns, and gloves) at the workplace, as well as to non-pharmacological preventive measures (NPPM) (physical distance defined as hardly ever and/or never approaches other people within 1.5 meters, social isolation as leaving home less than once a week, hand hygiene was defined as performing hand hygiene ≥ 6 times per period, and adherence to the use of a mask outside of the workplace was defined as on all outings and hardly ever and/or never removes the mask) outside of the workplace among 1,296 health care workers (HCWs), including if NPPM adherence was associated with COVID-19 in HCWs. High adherence to PPE was independently associated with younger age, professional category, work in an area of direct patient assistance; use of public transportation, or adherence to NPPM outside of the workplace.

Stress of Overseas Long-Distance Care During COVID-19: Potential "CALM"ing Strategies.

"CALM"ing strategies during COVID-19 pandemic. Created with BioRender.com.