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Edge and Fog Computing Business Value Streams through IoT Solutions: A Literature Review for Strategic Implementation
No full textEdge–fog computing and IoT have the ability to revolutionize businesses across all sectors and functions, from customer engagement to manufacturing, which is what makes them so fascinating and emerging. On the basis of research methodology by Webster and Watson (2020), 124 peer-reviewed articles were discussed. According to the literature, these technologies lead to reduced latency, costs, bandwidth, and disruption, but at the same time, they improved response time, compliance, security and greater autonomy. The results of this review revealed the open issues and topics which call for further research/examination in order for edge–fog computing to unveil new business value streams along with IoT capabilities for the organizations. Only by adopting and implementing precisely these revolutionary will new solutions organizations succeed in the digital transformation of the modern era. Despite the fact that they are cutting-edge solutions to business operations and knowledge creation, there are still practical implementation issues to be dealt with and a lack of experience in the strategic integration of the variable architectures, which hinder efforts to generate business value.13942
Exploiting Domain Knowledge to Address Class Imbalance in Meteorological Data Mining
No full textWe deal with the problem of class imbalance in data mining and machine learning classification algorithms. This is the case where some of the class labels are represented by a small number of examples in the training dataset compared to the rest of the class labels. Usually, those minority class labels are the most important ones, implying that classifiers should primarily perform well on predicting those labels. This is a well-studied problem and various strategies that use sampling methods are used to balance the representation of the labels in the training dataset and improve classifier performance. We explore whether expert knowledge in the field of Meteorology can enhance the quality of the training dataset when treated by pre-processing sampling strategies. We propose four new sampling strategies based on our expertise on the data domain and we compare their effectiveness against the established sampling strategies used in the literature. It turns out that our sampling strategies, which take advantage of expert knowledge from the data domain, achieve class balancing that improves the performance of most classifiers.12231240
Face reading the emotions of gelotophobes toward disparaging humorous advertising
No full textPrior research has indicated that gelotophobia, people’s fear of being laughed at, influences their emotions toward a disparaging humorous event. Based on two experiments with a sample of 50 Greek participants each, the present study employed face recognition software to explore the emotions of gelotophobes, when exposed to an advertisement. It further examined the moderating role of the type of advertisement (i.e. a disparaging humorous ad vs. a non-disparaging non-humorous ad) and identification with the victim of the joke, on gelotophobes' emotions. At higher levels of identification with the victim, gelotophobes indicated lower levels of joy, joyful (Duchenne) smile, and a positive emotional valence toward a disparaging-humorous advertisement as opposed to non-gelotophobes. Joy was also found to mediate the negative effects of gelotophobia on attitude toward the ad.1038811
Greek teachers’ difficulties & opportunities in emergency distance teaching
No full textDuring the first months of the COVID-19 pandemic, most schools worldwide were closed and online teaching replaced face-to-face teaching. This study reports the results of a survey among 845 teachers of primary and secondary education in Greece who taught their students fully remotely during the pandemic lockdown. These Greek teachers expressed the difficulties that they faced as well as the opportunities that they gained during this emergency distance teaching (EDT). Through qualitative content analysis this study found that everyone (students, teachers, and state) involved in EDT faced various difficulties due to digital infrastructure’s inadequacy, limited support by the state, limited digital educational material, as well as low digital literacy of students, parents, and even some teachers. On the other hand, there were many opportunities for teachers to experiment and apply their prior training knowledge on distance education to EDT. More concretely, teachers managed not only to improve their teaching and digital skills, to enrich and organise their educational material with more interesting online educational resources, but also to collaborate with colleagues, and to maintain effective communication with students. Similarly, students had opportunities to improve their digital and soft skills and receive personalized teaching. However, some teachers believed that their workload and their available free time increased while other teachers believed the opposite. Also, some teachers believed that students’ participation and engagement increased while other teachers believed the opposite. Finally, the study suggests actions to be taken to support the teachers in EDT such as improvements in digital infrastructure, digital educational material, teachers’ training, as well as support and clear guidelines by the educational authorities.19436137
Nasalance and perceived voice changes in patients undergoing septoplasty and turbinate hypertrophy reduction
No full textPurposeThe purpose of this study was to investigate the changes in voice nasality after septoplasty and turbinate hypertrophy reduction and to evaluate the effect of these changes on patients’ voice-related quality of life.MethodsSixty patients with nasal obstruction symptoms caused by septal deviation and inferior turbinate hypertrophy who underwent septoplasty and inferior turbinate hypertrophy reduction and 25 healthy controls were included. Active anterior rhinomanometry and acoustic rhinometry were utilized for the evaluation of nasal patency and nasometry was used for quantitative assessment of nasalance. All participants completed validated questionnaires for assessing nasal obstruction symptom severity, psychological status and the impact of voice performance on their quality of life preoperatively and 6 months after septoplasty.ResultsPatients presented preoperatively statistically significantly lower nasalance scores and higher VHI scores than controls (p < 0.05). Septoplasty and inferior turbinate hypertrophy reduction led to improvement of nasalance for the nasal text and the physical subscale of the VHI scores. Postoperatively, there were no statistically significant differences in nasalance and VHI scores between patients and controls. Significant correlations were found only for the baseline and the postoperative nasalance scores for the nasal text and the total nasal cavity volume (p < 0.05). Postoperatively, patients who presented significant improvement of nasal obstruction symptoms and resolution of stress levels were more likely to positively evaluate the impact of their voice quality on their daily life (OR: 2.32, 95% CI 1.08–5.15, p = 0.041 and OR: 3.06, 95% CI 1.15–7.04, p = 0.038, respectively).ConclusionSeptoplasty and inferior turbinate hypertrophy reduction may increase the nasal resonance, but in the long term, this change appears not to be significant enough. The severity of nasal obstruction symptoms and psychological status mainly affect the patients’ perceptual assessment regarding the effect of voice performance on their quality of life.27941899191
Performance management of SMEs: a systematic literature review for antecedents and moderators
No full textPurposeThe purpose of this study is to gain insight into existing empirical studies on performance management of small and medium-sized enterprises (SMEs). It categorizes the main antecedents for SMEs’ performance, the dimensions of SMEs’ performance and all variables used as moderators in the conceptual relationships.Design/methodology/approachThis study undertakes a systematic literature review of 58 articles published in 33 peer-reviewed academic journals from 2000 to 2020 followed by a synthesis of individual studies to analyze the trends and background of research into SMEs.FindingsA new academic conceptual model was developed grounded in selected theoretical lenses to advance our understanding of the different categories of antecedents, moderators and SMEs’ performance dimensions.Research limitations/implicationsThe author has provided a future research agenda in the context of SMEs. Future studies may investigate the role of different categories of determinants, the influence of key cultural values, the digital capability in SMEs and the Internet in the internationalization of SMEs.Practical implicationsThis paper offers a framework for both practitioners and scholars in thinking about those factors that may be critical for success in SMEs.Originality/valueThis is a systematic review that suggests a new conceptual model of what existing empirical studies have found on SMEs. It can be used to influence thinking and research design in the area of SMEs’ performance and success.71128931
Scalable On-Chain and Off-Chain Blockchain for Sharing Economy in Large-Scale Wireless Networks
No full textIn the future sharing economy, billions of underutilized IoT devices will be deployed to enable a powerful and large-scale sharing market that produces economic, environmental, and social benefits. Given the fact that communications in numerous IoT devices through wireless links are unreliable, blockchain technology, as a promising solution, has emerged to achieve reliable and secure sharing services in a decentralized manner. However, applying blockchain in large-scale wireless networks confronts scalability challenges. This motivates us to propose a real-time, trusted data interactive, and fine-grained transaction supportable sharing framework, the core of which is a novel two-layer scaling blockchain design. In the on-chain layer, sharing-oriented sharding is employed to enable secure and efficient processing of macro-transactions on the chain. In the off-chain layer, cross-zone off-chain channels are set up to provide real-time sharing transactions with high-frequency micro-trading scenarios. Finally, a proof-of-concept case study of electric vehicle sharing data is implemented with experimental results to demonstrate the feasibility of our framework.293323
Socio-Emotional Characteristics of Emergency Distance Teaching: A Mixed-Method Investigation in Greece
No full textAim/PurposeThe study examines the teachers’ perceptions towards a set of socio-emotional characteristics of distance education (DE) in primary and secondary schools during the Covid-19 pandemic. The examined characteristics include perceived joy, stress, effort/fatigue, isolation, inclusiveness, and collaboration/interaction.BackgroundThe transition to emergency distance education had a large socio-emotional impact on teachers. Recent evidence certifies an increase in mental health issues like stress and load. Studies also recognized online teaching barriers including difficulties in communication and interaction with students. This study focuses on the examination of the socio-emotional characteristics of distance education as perceived by primary and secondary education teachers in Greece. The study also investigates differences between primary and secondary education, teaching disciplines, and the role of individual factors like gender, age, and experience.MethodologyThe study used a mixed-method research design with closed-ended and open-ended questions on a sample of 845 teachers of primary and secondary education in Greece. The closed-ended questionnaire consisted of 19 items of socio-emotional DE characteristics, measured in a 5-point bipolar format.Exploratory Factor Analysis (EFA)was conducted on 16 items, indicating three components: (a) effort/fatigue, (b) inclusiveness, and (c) collaboration/interactivity. A single-item scale was considered for joy, fatigue, stress, and isolation. The finalized measurement model was evaluated in terms of item loadings, reliability of measures, convergent, and discriminant validity, with the help of the SmartPLS software. Descriptive statistics and percentages were calculated with the help of SPSS software. Because of the non-normal distribution of the data, non-parametric methods of Mann-Whitney and Kruskal-Wallis were performed to examine significant differences in teacher groups.The qualitative part of the analysis was conducted on text data received from two open-ended questions, on a sample of 602 cases. The identified qualitative constructs were investigated through content thematic analysis focusing on the identification of the socio-emotional codes and references, excluding non-relevant themes and cases.ContributionThe findings of the study contribute towards the deeper understanding of the teachers’ psychological or emotional state during the early stage of the Covid-19 emergency DE, as well as on the role of individual and other factors like gender, age, teaching stage, and teaching subject. The results can be leveraged during or after the pandemic, to design pedagogical or psychological practices and strategies to encourage and facilitate the teachers’ transition to DE.FindingsA measurement model of the teachers’ perceived socio-emotional characteristics towards emergency distance education was developed and validated. The model includes the components of: (a) effort/fatigue, (b) inclusiveness, (c) collaboration/interactivity, (d) isolation, (e) joy, and (f) stress.The quantitative results indicated that teachers experienced increased levels of fatigue, and perceived DE as difficult and time-consuming. Teachers of primary education reported significantly lower levels of perceived collaboration/interaction than secondary teachers. Female teachers reported significantly higher scores of both joy and stress, while the youngest age groups expressed the highest scores of joy. The teaching subject also revealed differences in fatigue. Through qualitative analysis, this study also identified several socio-emotional thematic codes revealing the teachers’ difficulties in interaction and communication with students as well as a set of emotional attributes like fatigue, joy, and stress.Recommendations for PractitionersTeachers should modify their face-to-face teaching material and adjust it to online teaching principles, avoiding future load and frustration. Different approaches should be implemented in primary and secondary education and indifferent teaching disciplines. Also, teachers should be trained on DE-oriented digital skills, ICT competencies, and socio-emotional skills, e.g., by receiving psychological and socio-emotional support from experts. Strategies to decrease fatigue and stress, especially in synchronous teaching should be traced by schools and educators.Recommendation for ResearchersThe findings provide theoretical evidence on the teachers’ socio-emotional attitude towards DE and their experiences in the first stages of the emergency remote education due to the Covid-19 pandemic.Impact on SocietyThis research highlights the perceived DE characteristics and the barriers to online teaching during Covid-19. Schools, educators, and society should collaborate to provide awareness and opportunities for successful distance education practices.Future ResearchThe survey is based on individual self-reported measures, and this restricts the deeper understanding of the findings. Hence, future research should extend this work by using different methods of data collection like for instance observations, course recordings, interviews, or focus groups.2105307
Spatio-temporal efficiency measurement under undesirable outputs using multi-objective programming: a GAMS representation
No full textTime series data in DEA often represent successive versions of the same unit (DMU). In order to assess efficiency of each DMU, several DEA techniques have been employed. One of the problems that conventional DEA models face is that the reference set, when dealing with time series data, is not constructed correctly. This is attributed to the fact that conventional DEA models examine the DMUs and extract their efficiency scores based only the spatial dimension. However, when dealing with time series data for DMUs in the DEA context, the temporal dimension should be also taken into account. This paper is based on Spatio-Temporal DEA (ST-DEA) model (Petridis et al. in Ann Oper Res 238(1–2):475–496, 2016) and extends the presented S-T DEA model by incorporating undesirable inputs/outputs. A GAMS representation of the model for the solution and explanation of ST-DEA model is shown through an illustrative example. The scope of the paper is to analyze the concept of ST-DEA model and demonstrate its applicability via an application explained in GAMS optimization software.3111183120
Τhe long recession and economic consequences of the covid-19 pandemic
No full textIn this article, we argue the rate of profit in combination with the movement of the real net profits determines the phase-change of the economy in its long cyclical pattern. Since WWII, the US and the world economy have experienced two such long cycles. The pandemic COVID-19 has deepened a recession that has been already underway since 2007. The growth rates in the first post-pandemic years are expected to be high; however, soon after, the economies will find themselves back to their old recessionary growth paths. The onset of a new long cycle requires the restoration of profitability, which can be sustained only through the introduction of ‘disruptive’ innovations backed by suitable institutional arrangements.8132132