Multi-objective Evolutionary Discretization of Gene Expression Profiles: Application to COVID-19 Severity Prediction

Machine learning models can use information from gene expressions in patients to efficiently predict the severity of symptoms for several diseases. Medical experts, however, still need to understand the reasoning behind the predictions before trusting them. In their day-to-day practice, physicians prefer using gene expression profiles, consisting of a discretized subset of all data from gene expressions: in these profiles, genes are typically reported as either over-expressed or under-expressed, using discretization thresholds computed on data from a healthy control group. A discretized profile allows medical experts to quickly categorize patients at a glance. Building on previous works related to the automatic discretization of patient profiles, we present a novel approach that frames the problem as a multi-objective optimization task: on the one hand, after discretization, the medical expert would prefer to have as few different profiles as possible, to be able to classify patients in an intuitive way;on the other hand, the loss of information has to be minimized. Loss of information can be estimated using the performance of a classifier trained on the discretized gene expression levels. We apply one common state-of-the-art evolutionary multi-objective algorithm, NSGA-II, to the discretization of a dataset of COVID-19 patients that developed either mild or severe symptoms. The results show not only that the solutions found by the approach dominate traditional discretization based on statistical analysis and are more generally valid than those obtained through single-objective optimization, but that the candidate Pareto-optimal solutions preserve the sense-making that practitioners find necessary to trust the results. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

A Study on the Influence of Task-driven Instruction on Learning Outcomes in Online Learning under COVID-19

Interest in online learning is increasing due to its advantages and pedagogical potential. However, few studies have investigated the effects of task-driven instruction on learning outcomes. This study examines the effectiveness of the application of task-driven instruction as a means of verifying that the use of task-driven instruction in online learning is effective by comparing changes in students' grades, intrinsic motivation, perceived social presence, and perceived cognitive load before and after the application of the method. Eighty high school students (33 males) were recruited for this experiment. Prior to the experiment, the purpose and steps of the study were explained frankly and candidly, problems and risks that might arise from participation in the study were pointed out, the benefits that would result from participation in the study were explained, and the possibility of voluntarily withdrawing from the study at any time was clearly communicated and approved by the study subjects or guardians. They were divided into experimental group I and control group II, with 40 students in each group. The results of the study showed that after the implementation of the instruction, the experimental group I performed significantly better than the control group II. In addition, the experimental group II outperformed the control group II in terms of perceived intrinsic motivation, social presence, and cognitive load. © 2023 ACM.

A CNN for COVID-19 Detection Using ECG signals

We developed an end-to-end automatic algorithm for the detection of signs of COVID-19 virus infection in ECGs. We analyzed 12-lead ECGs from patients infected by COVID-19 (C-group) and from a control group (NC-group). The C-group (896 cases) included patients (age range [19-96] years) hospitalized at Ospedale San Matteo in Pavia (Italy) during the first 2020 pandemic outbreak. Infection was confirmed by nasal swab testing. The NC-group (also 896 cases) was built by collecting ECG in sinus rhythm from 3 datasets: Georgia ECG (USA), PTB-XL (Germany) and CPSC 2018 (China). Control ECGs were matched by gender, age and heart rate. An additional control group, only used for testing, was extracted from the Ningbo (China) database. A 4-layers convolutional neural network (CNN), with increasing filter size plus a final fully connected (FC) layer, was designed to classify C vs NC-group. The CNN was trained and k-fold cross validated (k=7) on 1536 ECGs (1316 for testing-220 for validation). Every fold model was used to classify the remaining, separate common test set of 256 ECGs. The accuracy was 0.86 ± 0.01 on validation, 0.86 ± 0.01 on the test set. The FPR on the NC-group was 0.14 ± 0.03 on validation, 0.13 ± 0.02 on test and 0.10 ± 0.01 on the Ningbo test set (p > 0.05,ns) showing that no bias was induced by the selection of datasets. © 2022 Creative Commons.

A natural antiviral to speed up Sars-Cov2 negative test: an evaluation of efficacy and safety.

Since November 2019, the SARSCov2 virus has plagued the world, evolving into ever newer, more immuneevasive and infectious variants. From February to June 2022, a doubleblind study was carried out with a control group by administering a mixture of natural products of known antiviral and antiinflammatory activity. Thirteen subjects ranging in age from 22 to 54 years (mean 36.2) were involved, five of whom (50+ years, mean age 52) were not included in the therapy with synthetic antivirals. All took twicedaily therapy for five days within 48 hours of diagnosis of symptomatic SARSCov2 infection, in addition to the normal treatment protocol of NSAIDs, lactoferrin and vitamins. Seven patients with an average age of 28.7 years (2251) received a placebo. The control group consisted of 67 patients, all treated with the abovementioned basic protocol with an average age of 33.5 years (2159). Positivity and negativity were performed by antigen swab at the same site. Data were processed using Excel, while SPSS software was used for the nonparametric test. The patients treated with the natural antiviral supplement became negative on average after 9.0 days. The four patients over 50 who finished the therapy became negative after 10.0 days on average, the others in 8.3 days. Patients in the placebo group became negative in 10.6 days. Patients in the control group on average after 10.6 days (those <50 in 10.4, those >50 in 11.2). The duration of the symptoms was similar in all groups and no patient experienced an aggravation. The patients treated with the antiviral based on natural products showed an earlier negative reaction than the control group and the placebo, especially in the younger patients. The occurrence of potential side effects cannot be attributed to the treatment directly, as it is part of the normal clinical symptoms of the disease. The study does not have valid scientific reliability due to the small number of patients recruited, but nevertheless shows an interesting reduction in positivity of 21.7% in subjects under 50 years of age. Further studies are still needed (English) [ FROM AUTHOR] Dal novembre 2019 il virus sarscov2 affligge il mondo, evolvendosi in sempre nuove varianti sempre più immunoevasive e contagiose. Dal febbraio al giugno 2022 è stata effettuato uno studio in doppio cieco con gruppo di controllo, tramite somministrazione di una miscela di prodotti naturali di conosciuta attività antivirale ed antinfiammatoria a 13 soggetti di età variabile tra i 22 ed i 54 anni (media 36.2), 5 dei quali (50+ anni, età media 52) non includibili nella terapia con antivirali di sintesi. Tutti hanno assunto la terapia 2 volte al giorno per 5 giorni entro 48 ore dalla diagnosi di infezione sintomatica da sarscov2 oltre al normale protocollo terapeutico a base di fans, lattoferrina e vitamine. 7 pazienti con un'età media di 28.7 anni (2251) hanno ricevuto un placebo. Il gruppo di controllo è stato di 67 pazienti, tutti trattati con il sopracitato protocollo di base con un'età media di 33.5 anni (2159). La positività e la negatività sono stati effettuati con tampone antigenico effettuato nella stessa sede. I dati sono stati trattati tramite Excel, mentre per il test non parametrico è stato utilizzato il software SPSS. I pazienti trattati con l'integratore antivirale naturale si sono negativizzati in media dopo 9,0 giorni. I 4 pazienti ultracinquantenni che hanno terminato la terapia si sono negativizzati in media dopo 10,0 giorni, gli altri in 8,3 giorni. I pazienti del gruppo placebo si sono negativizzati in 10,6 giorni. I pazienti del gruppo di controllo in media dopo 10,6 giorni (under 50 in 10,4, gli over 50 in 11,2). La durata della fase sintomatologica è stata sovrapponibile in tutti i gruppi e nessun paziente ha avuto un aggravamento. I pazienti trattati con l'antivirale a base di prodotti naturali hanno mostrato una negativizzazione precoce rispetto al gruppo di controllo ed al placebo, soprattutto nei pazienti più giovani. La comparsa di potenziali effetti collaterali non è direttamente attribuibile al trattamento, rientrando nella normale manifestazione clinica della malattia. Lo studio non ha una valida attendibilità scientifica a causa del numero ridotto dei pazienti reclutati, ma mostra comunque un'interessante riduzione della positività del 21,7% nei soggetti sotto i cinquant'anni. Ulteriori studi sono comunque necessari. (Italian) [ FROM AUTHOR] Copyright of Giornale di Medicina Militare is the property of Difesa Servizi S.p.A. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

The Impact of Technology and Quality Improvement on Hba1c at a National Level

Background and Aims: Denmark started a national improvement project focusing on childhood diabetes in spring 2020 at the very beginning of the Covid-19 pandemic. This study reports the development in glycemic control and BMI for the years 2020 +/- 2022 a period where also new automated insulin delivery systems were introduced in Denmark. Method(s): Data are retrieved from the quality improvement data from each visit 2019-2022. Children age 0-17.9 years were included. Serial diagrams were used to follow quality indicators month by month. Definition of overweight was BMI above 2 standard deviation (SD) according to age and sex. Result(s): All 16 clinics in Denmark participated and during the period 3 seminars were held and 8 webinars of 1-2 hours. During the webinars different clinics presented their projects and material and ideas were shared. During the study period between 377 +/- 938 single HbA1c values per month were reported and contributed to the serial diagrams. There was a significant decline in mean HbA1c from 2019 (mean of 58.3 mmol/mol) to september 2021 (54 mmol/mol) and an increase in all age groups obtaining treatment goal below 53 mmol/l. There was an increase in the percentage of children with BMI above 2SD. Conclusion(s): There was signs of decrease in HbA1c from the beginning of 2021 after 9 months with quality improvement and just as automatic insulin delivery was introduced with a simultaneous increase in BMI.

Application of online-Pilates exercise based on information visualization training feedback in elderly people with low back pain: A randomized controlled trials

Objective: To investigate if remote Pilates exercises for older patients with low back pain(LBP) in the post-COVID-19 era may be successfully performed using a pressure biofeedback unit (PBU)-based information visualization training feedback technology. Design: A total of 40 older patients with LBP were randomly allocated to a control group ($\mathrm{n}=20$) receiving clinical Pilates training instruction via video link or an experimental group ($\mathrm{n}=20$)) with tele-Pilates exercise based on information visualization training feedback. The program had two 60-minute sessions per week for the whole eight-week duration. Pain was assessed by a visual analogue scale(VAS), the Oswestry Disability Index(ODI) was used to evaluate physical function, the modified Schober test was used to measure lumbar range of flexion and extension, and core strength was assessed by the PBU. Results: Between-group analysis showed significant variations in the degree of disability in the intervention group compared to the control group ($\mathrm{p} < 0.001$), lumbar flexibility ($\mathrm{p}=0.02$) and core muscle activation capacity ($\mathrm{p} < 0.001$). And level of pain was significantly decreased in both two groups. Conclusions: In elderly patients with LBP, an 8-week remote Pilates exercise based on information visualization training feedback is beneficial in reducing disability, pain, and enhancing flexibility and core muscle strength. © 2022 IEEE.

Toward the Development of writing conference papers skills in Engineering students-COVID 19 implementation experience

COVID-19 has caused global changes in the way of teaching and learning. The new forms of teaching how to write papers to Engineering students that began in 2020 may become a new pedagogical alternative. The literature had already shown the advantages of using technology for teaching, highlighting the possibilities of collaboration, and to give students a leading role in the development of their learning process. The article shows the experience of teaching writing conference papers to Engineering students under a virtual environment. The study was experimental with 54 students in two groups: Control Group and Experimental Group. The students were evaluated through an instrument that considered three dimensions: planning, writing and reviewing. Results demonstrated that it is possible to develop technical writing skills in Engineering students in a virtual environment. © 2022 IEEE.

Construction of a Blended Teaching Mode for Medical Parasitology in China during COVID-19 Pandemic

Facing the challenge of COVID-19 pandemic, online education rapidly occupied the daily teaching in China, which promoted the development of "Online+Offline"(blended) teaching. Medical Parasitology majorly aims to cultivate students' basic knowledge of Parasitology and the ability of "diagnosis and control of parasitic diseases". The Massive Online Open Course (MOOC), intelligent teaching software and Parasitology multimedia laboratory are used for blended teaching. Theoretical teaching includes intensive lectures, self-learning and flipped classrooms. Practices are taught in blended manner. The most representative means is the flipped classroom integrating learning with application through "case discussion - laboratory examination - uploading diagnosis basis on line - group report for peer learning". An evaluation combining formative and summative evaluation, online and offline assessment is jointly applied. We selected Clinic Medicine major as the experimental group, the Basic Medicine, Medical Experimental Technology and Biotechnology majors as the control group. The experimental group was taught in the blended teaching mode of "combining virtuality with reality, learning with application";and the control group was taught in the traditional mode of lectures in big group and practices in small groups. The scores of the final computer test and the final offline experimental test were used in comparison. The experiment and theory scores of the experimental group are both significantly higher than that of the control group. The blended teaching is highly recognized by our students, and the teaching mode has been widely demonstrated and recommended to other courses in and out of the university. This mode comprehensively cultivated students' basic knowledge of Parasitology, and the ability of diagnosis and control of parasitic diseases. This blended teaching mode of "combining virtuality with reality, learning with application"effectively improved students' academic performance and application abilities, and well cultivated students' thinking of diagnosis and control of parasitic diseases. © 2022 ACM.

Burnout among Nursing Workers Who Provide Nursing Care for People Infected with COVID-19

Background: The unpredictable nature of the new COVID-19 pandemic and what is already troubling incidents of affecting nursing workers can have a significant impact on their psychological well-being. Objective: To describe the prevalence of burnout among nursing personnel caring for patients with COVID-19 and associated factors. Study Design: cross-sectional study. Setting: Alhossien Teaching Hospitals designated to isolate patients with COVID-19 in Thi Qar Governorate. Participants: A sample of 50 nurses practitioners in the study sites who were caring for COVID- 19 patients. Measurements: age, gender, marital status, job title, certificate, job category, number of years of service, working period, hospitalization, and work load, as well as burnout level in each subscale consist (12)items. Results: Nurses working in isolation hospitals suffer from high levels of burnout, emotional exhaustion, depersonalization, and personal underachievement. Limitations: There was no control group and therefore we cannot claim a causal relationship between COVID-19 and the level of fatigue observed. Not all confounders may have been accounted for. Conclusions: Burnout is prevalent among nurses caring for COVID-19 patients. Age, gender, job category, and location of practice contribute to the level of burnout experienced by nurses. Recommendations: Psychologically rehabilitate nursing workers under the supervision of specialists and give them financial and moral rewards to compensate for the harm they have suffered. © 2022 IEEE.

Age-related Eye Tracking Study of Reading COVID-19 Texts with Negative Elements

The worldwide COVID-19 pandemic leads to the development of stress disorders, increased anxiety in the society. One of the strongest factors leading to the development of anxiety, stress in society during a pandemic is the Mass Media. The mechanisms of stressogenic effects of Mass Media remain not completely clear. The aim of this study was to evaluate age-specific characteristics of gaze behavior related to the perception of anxiety-provoking information. The study was performed basing on the 189 volunteers (164 participants aged between 17 and 22 years old (students, control group), 25 people aged between 59 and 71 aged 59 to 71 (experimental group). We surveyed participants to determine their level of stress, depression, and anxiety and analyzed eye-tracking data during the text perception by using web-tracking (EyePass). Results showed the significant age-related differences in gaze behavior while reading text with negative text elements. Aged adults had shorter median fixation duration. There was no difference between groups in the amount of the fixation. We can assume that except age factor other ones might contribute to our result, namely the occupation of participants, professors at the Institute of Journalism, with developed professional skills (reading pattern, method of information perception) but from other side higher vulnerability to adverse COVID-19 outcomes compared to younger adults. © 2022 IEEE.

SlowFast GCN Network for Quantification of Parkinsonian Gait Using 2D Videos

Parkinson's disease(PD) is a progressive neu-rodegenerative disease defined by clinical syndrome including bradykinesia, tremor and postural instability. The PD-related disability and impairment are usually monitored by clinicals using the MDS-UPDRS scale. However, due to COVID-19, it became much harder for the patients to reach hospitals and obtain necessary assessment and treatment. Nowadays, 2D videos are easily accessible and can be a promising so-lution for on-site and remote diagnosis of movement disorder. Inspired by the frequency-based video processing mechanism of human visual system, we propose a video-based SlowFast GCN network to quantify the gait disorder. The model consists of two parts: the fast pathway and the slow pathway. The former detects characteristics such as tremor and bilateral asymmetry, while the latter extracts characteristics such as bradykinesia and freezing of gait. Furthermore, in order to investigate the influence of age on the model performance, an aged control group and a young control group were set up for verification. The proposed model was evaluated on a video dataset collected from 68 participants. We achieved a balanced accuracy of 87.5% and precision of 87.9%, which outperformed existing competing methods. When replacing the young healthy controls with the same number of older controls, the balanced accuracy and precision were decreased by 10.4% and 9.7%, which indicates that age has a significant effect on the model perfomance. © 2022 IEEE.

Comparison of test-negative and syndrome-negative controls in SARS-CoV-2 vaccine effectiveness evaluations for preventing COVID-19 hospitalizations in the United States.

BACKGROUND: Test-negative design (TND) studies have produced validated estimates of vaccine effectiveness (VE) for influenza vaccine studies. However, syndrome-negative controls have been proposed for differentiating bias and true estimates in VE evaluations for COVID-19. To understand the use of alternative control groups, we compared characteristics and VE estimates of syndrome-negative and test-negative VE controls. METHODS: Adults hospitalized at 21 medical centers in 18 states March 11-August 31, 2021 were eligible for analysis. Case patients had symptomatic acute respiratory infection (ARI) and tested positive for SARS-CoV-2. Control groups were test-negative patients with ARI but negative SARS-CoV-2 testing, and syndrome-negative controls were without ARI and negative SARS-CoV-2 testing. Chi square and Wilcoxon rank sum tests were used to detect differences in baseline characteristics. VE against COVID-19 hospitalization was calculated using logistic regression comparing adjusted odds of prior mRNA vaccination between cases hospitalized with COVID-19 and each control group. RESULTS: 5811 adults (2726 cases, 1696 test-negative controls, and 1389 syndrome-negative controls) were included. Control groups differed across characteristics including age, race/ethnicity, employment, previous hospitalizations, medical conditions, and immunosuppression. However, control-group-specific VE estimates were very similar. Among immunocompetent patients aged 18-64 years, VE was 93 % (95 % CI: 90-94) using syndrome-negative controls and 91 % (95 % CI: 88-93) using test-negative controls. CONCLUSIONS: Despite demographic and clinical differences between control groups, the use of either control group produced similar VE estimates across age groups and immunosuppression status. These findings support the use of test-negative controls and increase confidence in COVID-19 VE estimates produced by test-negative design studies.

The Effectiveness of ScratchJr in Enhancing Preschool Children's Problem-Solving Skills

Utilizing digital media serves as one of the teachers' efforts to develop children's problem-solving skills. By using the ScratchJr program, teachers can develop different play activities to stimulate children's problem-solving skills. This study sought to examine the effectiveness of the ScratchJr computer program in enhancing 5-6 years old children's skills during the Covid-19 pandemic. To this end, a quasi-experimental design was applied. The study was conducted in an Islamic kindergarten in Surakarta by assigning 29 students to an experimental group and another 29 students to a control group. The data were collected using test and nontest techniques. The test-based data collection was done using pre-and post-tests, while the non-test data collection was carried out through observation. The hypothesis was tested using parametric statistics because the data were considered to be normally distributed and homogeneous. An independent sample t-test was applied to analyze the data. The result indicates that the ScratchJr program effectively enhances 5-6 years old children's problem-solving skills, as shown by the significant difference between the score of experimental and control groups (ρ < 0.05). © 2021 ACM.

The measurement and discriminant analysis of enterprise resilience

The current environment is complex and uncertain. COVID-19 not only brings challenges to the government’s public health governance, but also disrupts the industrial supply chain and poses a crisis to the survival and transformation development of enterprises, which has raised severe tests to the resilience of enterprises and has also become an important issue for scholars to study. The existing academic research and practical experience show that resilience is the key ability to support enterprises to survive the crisis, and stability and adaptability are the main characteristics of resilient enterprises. Stable performance improves enterprise operation efficiency, and adaptability improves strategic flexibility. This paper focuses on the quantitative study of enterprise resilience, analyzes the relationship between stability and adaptability from the perspective of paradox, and selects efficiency and flexibility as discriminant variables from the outcomes of resilience. Based on the financial data of the resilient enterprises and the control group, the variables affecting the resilience of enterprises were determined by discriminant analysis and the measurement indexes were constructed to establish the calculation method of enterprise resilience. By calculating the scores of resilient enterprises and the control group, it is found that the scores of resilient enterprises are significantly higher than the control group in terms of stability and adaptability, which verifies the paradoxical relationship between them. This shows that the resilient firm is not an either-or choice between stability and adaptability, and there is a continuously distributed behavior space between them. Therefore, resilient enterprises adapt to the changing and highly uncertain business environment through constant change and innovation while maintaining the bottom line of survival in the crisis. © 2022, Editorial Board of Journal of Systems Engineering Society of China. All right reserved.

Influence of a Mobile Application With Augmented Reality ANATOMY-3D in Learning of Bone System

The pandemic caused by COVID-19, although it is considered a threat to humanity, also changed the life of the entire planet in different aspects, one of them is education because in a short time it converted the classic face-to-face stage into a virtual stage, a product of compulsory confinement in almost every country in the world. In Peru, this change has many negative consequences, since teachers do not have or know of virtual technological tools to support the student in the learning process. To alleviate this problem, an augmented reality mobile application called ANATOMY-3D was developed, to help students learn and recognize the bones of bone system in 3D. The influence of ANATOMY-3D on the learning of students from a school in the Apurimac region, in Peru, was evaluated, for this, 53 students were taken as a sample, dividing them into an experimental group (GE1) and a control group (G2). the experimental group used ANATOMY-3D and the control group used the traditional method. The results were analyzed in three dimensions: usability, motivation, and a knowledge questionnaire. The results showed that ANATOMY-3D has a good level of usability, promotes better motivation in students to use ANATOMY-3D compared to the traditional method. Finally, the questionnaire showed that ANATOMY-3D positively influences the learning and recognition of the bones of bone system, as it achieved better scores for the experimental group (G1), compared to the control group (G2), with a difference of 0.88 in the mean of the grades. © 2021 IEEE.

Recovery of previously mastered techniques in a shift from classical to beach volleyball by means of biomechanical analysis: (On the example of an attack spike)

The paper summarizes the results of study on the recovery of previously mastered skills of attack motions when transferring from classical to beach volleyball by means of biomechanical analysis. The purpose of the study was to evaluate advantages of the implementation of biomechanical analysis in the recovery of previously mastered techniques in beach volleyball. Comparison of the efficiency of the recovery of previously mastered techniques was studied on the example of the attack spike. Twelve male university team players participated in this study (age: 20.5 ± 0.72 years;body mass: 79.8± 7.6 kg;height: 186.7 ± 5.49 cm) were divided into experimental group (EG) and control group (CG). Personal spike profiles for beach volleyball were used in the experimental group to guide the technique recovery. The spike efficiency was assessed on three most informative parameters: initial ball velocity, hitting the court and hitting the assigned zone. The generalized value of spike efficiency was calculated as the parameters average. The results showed substantial acceleration of skill recovery to the previously archived level both in in seasonal shifts of the experimental group and after the constrained layoffs due to COVID-19 restrictions. © 2021 ACM.

Effect of Alpha Wave-Containing Music on the Psychological Stress Level of Hospital Staffs and their Cognitive Performance

This study aims to investigate the effect of alpha music therapy that is an affordable, easily implemented, and sustainable method on stress level, cognitive functions, and physiological response of hospital staff amidst the context of the COVID-19 pandemic. The testing group was required to listen to alpha music for two weeks. Stress questionnaires, cognitive tasks, and physiological data were collected before and after the intervention. Blood pressure and heart rate between the two groups do not differ significantly and change after intervention. The increase in PSS scores and fast response time in the Matrix Task of the Control group indicate increasing stress levels, reduced attention, and remembering ability. These results of the Control group explain the high workload at the year-end and COVID-19 outbreak in Vietnam occurring during the second data collection week. In contrast, both the PSS and Respond time measures suggest a positive effect of alpha music on the Testing group. © 2021 ECBIOS 2021. All rights reserved.

An experimental study on the effects of gamification on task performance

This experimental study investigates the effects of gamification on task performance. A between-group experimental design was used in relation to the Covid-19 pandemic where the participants were asked to perform tasks related to: a) hygiene and infection (wash hands, keep distance, etc.), b) routines (walk every day, be social with friends, clean the house, etc.), and c) personal issues (learn something new, check in with a friend, etc.). The test group used an application based on a gamified system and the control group used the same application without a gamified system. Our main findings suggest that gamification has increased the quality of work in task performance and subsequent deliveries over time. In addition, gamification has positively affected on-time deliveries. If a deadline was missed, gamification motivated users to always deliver. The contribution of this study to research and implications for management are discussed, and future research avenues are presented. © 2021 Elsevier B.V. All rights reserved.

Mechanical Analysis of Ice-Composite and Fibber Strength by Daily Tools

The analysis on mechanical properties of ice-composite focus on three aspects. The first is the novelty of the material. As an ice composite, the selection and placement of different fibres will have a crucial impact on the material and properties of the composite. Regarding the type of fibre, 10 groups of controlled experiments are designed totally with materials commonly used in daily life, with three samples in each group and 33 samples in total. The fillers include cloth of socks, polyester fibre plastic bags (hard, soft, garbage sorting bags), pulp, hemp ropes, nylon ropes, non-woven fabrics, bamboo fibre, and the mask material applied in preventing COVID-19 specially. Considering that in most cases, the mask is a one-off, it is also creatively thought of using disinfected waste masks as reinforcement material for the ice-composite to reduce the waste of recyclable materials. Considering that disposable masks commonly used in this scheme usually consist of an inner and outer layer, as shown in the figure. The applicability of these two fibres was investigated by adding these materials prepared by the inner and outer layers of masks into the Ice-composite. In order to systematically study the influence of different variables on ice composites, different control groups in four directions are set: Fibre type, fibre content, fibre length, and fibre orientation. For each control group, more than 2 types of materials were tested and relevant parameters were analysed according to the results. In addition, as a result of the experiment environment to room temperature, and in the process of operation, hands and other body parts contact could accelerate the melting of the ice, leading to the change of the sample properties. To conquer this problem, a blank control group which contains only ice at room temperature is set to make a comparison and provide a standard for determining the improvement of fibre added ice-composite. (The parameters measured in this sample will be used as correction factors in the experiment so that the real properties of the resulting ice composite can be measured.) Considering the influence of fibre orientation on material properties, an extra control group for the same kind of materials is set: One group is stirred evenly with the matrix, and the other group is placed vertically along the direction of the box. In terms of testing, the mechanical properties of the products are mainly tested, including Stiffness Properties, Elastic property. Three related physical properties, the elastic modulus E, the shear modulus G, and the Poisson's ratio V, are measured to evaluate. Tensile and compressive strength in X, Y, and Z directions are also considered. In particular, different evaluation systems are established for uniform and multilayer unidirectional composite (longitudinal). In addition, a series of properties, such as bend strength, impact strength, and fracture toughness are measured. Considering the limits of daily measuring instruments, the melting of ice in the operation process affects the measurement of normal strain and the fact that the strain of ice composite material is relatively small, it is creatively thought to use a laser pointer and cosmetic mirror which are common in the multimedia classroom of the university campus to magnify the tiny deformation to facilitate measurement. In terms of the result presentation, it is tried to use broken line charts to show the correlation between various variables and material properties. Finally, the error sources existing in the experiment has been summarized and some improvement plans are proposed according to the existing problems of this experiment. © 2021 Institute of Physics Publishing. All rights reserved.