Utilizing a Facebook closed group for EFL e-learning environment: Students’ views

This study was conducted out of the researcher’s teaching reflection while teaching English as a foreign language (EFL) online class during the pandemic of COVID-19, a time when face-to-face courses had to be converted to online classes. Her choice of educational tool for her EFL e-learning environment utilized a Facebook closed group. Her experiences in utilizing a Facebook closed group for her EFL e-learning environment and the students’ views were the main topics of this study. Eighteen EFL freshmen participants were selected in this study. The researcher used data from a questionnaire with some closed and open-ended questions. The findings indicated that the students found the Facebook closed group a comfortable, practical, and useful e-learning environment. The students’ familiarity with the interface helped them to immediately focus on the class activities instead of learning how to use the tool. Most students viewed the Facebook closed group as positive for class interactions, creative work, opinions, and express feelings. A few dislike voices were related to the display quality of Facebook, the asynchronous and silent communication on Facebook. Accordingly, utilizing a Facebook closed group might be worth considering for learners who have not been adequately prepared with the technology for joining an online class.

IRTS: An Intelligent and Reliable Transmission Scheme for Screen Updates Delivery in DaaS

Desktop-as-a-service (DaaS) has been recognized as an elastic and economical solution that enables users to access personal desktops from anywhere at any time. During the interaction process of DaaS, users rely on screen updates to perceive execution results remotely, and thus the reliability and timeliness of screen updates transmission have a great influence on users’ quality of experience (QoE). However, the efficient transmission of screen updates in DaaS is facing severe challenges: most transmission schemes applied in DaaS determine sending strategies in terms of pre-set rules, lacking the intelligence to utilize bandwidth rationally and fit new network scenarios. Meanwhile, they tend to focus on reliability or timeliness and perform unsatisfactorily in ensuring reliability and timeliness simultaneously, leading to lower transmission efficiency of screen updates and users’ QoE when network conditions turn unfavorable. In this article, an intelligent and reliable end-to-end transmission scheme (IRTS) is proposed to cope with the preceding issues. IRTS draws support from reinforcement learning by adopting SARSA, an online learning method based on the temporal difference update rule, to grasp the optimal mapping between network states and sending actions, which extricates IRTS from the reliance on pre-set rules and augments its adaptability to different network conditions. Moreover, IRTS guarantees reliability and timeliness via an adaptive loss recovery method, which intends to recover lost screen updates data automatically with fountain code while controlling the number of redundant packets generated. Extensive performance evaluations are conducted, and numerical results show that IRTS outperforms the reference schemes in display quality, end-to-end delay/delay jitter, and fairness when transferring screen updates under various network conditions, proving that IRTS can enhance the transmission efficiency of screen updates and users’ QoE in DaaS.

Immersive reading in virtual and augmented reality environment

Purpose This study aims to investigate “immersive reading,” which occurs when individuals read text while in a virtual reality (VR) or augmented reality (AR) environment. Design/methodology/approach In Experiment 1, 64 participants read text passages and answered multiple-choice questions in VR and AR head-mounted displays (HMDs) compared with doing the same task on liquid crystal display (LCD). In Experiment 2, 31 participants performed the same reading tasks but with two VR HMDs of different display quality. Findings Compared with reading on LCD as the baseline, participants reading in VR and AR HMDs got 82% (VR) and 88% (AR) of the information accurately. Participants tended to respond more accurately and faster, though not statistically significant, with the VR HMD of higher pixel density in the speed-reading task. Originality/value The authors observed the speed and accuracy of reading in VR and AR environments, compared with the reading speed and accuracy on an LCD monitor. The authors also compared the reading performance on two VR HMDs that differed in display quality but were otherwise similar in every way.

A Tabu Search Algorithm for General Threshold Visual Cryptography Schemes

In Visual Cryptography Schemes (VCSs), for message n transparencies are generated, such that the original message is visible if any k of them are stacked. VCS especially for large values of k and n, the pixel expansion’s reduction and enhancement of the recovered images’ display quality continue to be critical issues. In addition to this, it is challenging to develop a practical and systematic approach to threshold VCSs. An optimization-based pixel-expansion-free threshold VCSs approach has been proposed for binary secret images’ encryption. Along with contrast, blackness is also treated as a performance metric for assessing the recovered images’ display quality. An ideally secure technique for a secret image’s protection through its partition into shadow images (known as shadows) is the Visual Secret Sharing (VSS) scheme. Acquirement of a smaller shadow size or a higher contrast is the VSS schemes’ latest focus. The white pixels’ frequency has been utilized to demonstrate the recovered image’s contrast in this work. While the Probabilistic VSS (ProbVSS) scheme is non-expansible, it can also be readily deployed depending upon the traditional VSS scheme. Initially, this work has defined the problem as a mathematical optimization model such that, while contingent on blackness and density-balance constraints, there is the maximization of the recovered images’ contrast. Afterward, an algorithm dependent on the Tabu Search (TS) is devised in this work for this problem’s resolution. Multiple complicated combinatorial problems have been successfully resolved with the powerful TS algorithm. Moreover, this work has attempted to bolster the contrast through the density-balance constraint’s slight relaxation. Compared to the older techniques, the proposed optimization-based approach is superior regarding the recovered images’ display quality and the pixel expansion factor from the experimental outcomes.

Subjective and Objective Quality Assessments of Display Products

In recent years, people’s daily lives have become inseparable from a variety of electronic devices, especially mobile phones, which have undoubtedly become necessity in people’s daily lives. In this paper, we are looking for a reliable way to acquire visual quality of the display product so that we can improve the user’s experience with the display product. This paper proposes two major contributions: the first one is the establishment of a new subjective assessment database (DPQAD) of display products’ screen images. Specifically, we invited 57 inexperienced observers to rate 150 screen images showing the display product. At the same time, in order to improve the reliability of screen display quality score, we combined the single stimulation method with the stimulation comparison method to evaluate the newly created display products’ screen images database effectively. The second one is the development of a new no-reference image quality assessment (IQA) metric. For a given image of the display product, first our method extracts 27 features by analyzing the contrast, sharpness, brightness, etc., and then uses the regression module to obtain the visual quality score. Comprehensive experiments show that our method can evaluate natural scene images and screen content images at the same time. Moreover, compared with ten state-of-the-art IQA methods, our method shows obvious superiority on DPQAD.

The Shape of Agency

In this book Shepherd offers a perspective on the shape of agency by offering interlinked explanations of the basic building blocks of agency, as well as its exemplary instances. In the book’s first part, he offers accounts of phenomena that have long troubled philosophers of action: control over behavior, non-deviant causation, and intentional action. These accounts build on earlier work in the causalist tradition and undermine the claims of many that causalism cannot offer a satisfying account of non-deviant causation, and therefore intentional action. In the book’s second part, he turns to modes of agentive excellence—ways that agents display quality of form. He offers a novel account of skill, including an account of the ways that agents display more or less skill. He discusses the role of knowledge in skill and concludes that while knowledge is often important, it is inessential. This leads to a discussion of knowledge of action—of the way that knowledge of action and knowledge of how to act informs action execution. Shepherd argues that knowledgeable action includes a unique epistemic underpinning. For in knowledgeable action, the agent has authoritative knowledge of what she is doing and how she is doing it when and because she is poised to control her action by way of practical reasoning.

Bioenrichment using Satureja montana L. essential oil for the prevention against photooxidation of flavored extra virgin olive oil during light display

Background: In response to consumer demand for novel and healthy foods, the presence in the market of olive oils (OOs) flavored with different plants, spices, herbs or fruits is increasingly common. All these flavoring agents have been used over the years due to their content in compounds with biological activities. Aim: The aim of this study was to investigate the potential role of the addition of S. montana EO at 100 ppm (0.01%, v/v), known for its high content of bioactive compounds, good flavor, and aroma in improving oxidative stability and quality profile of EVOO subjected to conditions causing accelerated oxidation (Light storage at 900 lux). Materials and methods: The S. montana EO chemical components were identified using Gas Chromatography–Mass Spectrometry (GC/MS). Enriched and non-enriched EVOO samples were examined as function of time (30, 60 and 90 days) of display for different quality indices. Results: Using GC/MS analysis of S. montana EO: thymol (28.36%), carvacrol (17.45%), p-cymene (10.91%), trans-caryophyllene (5.54%), ɤ-terpinene (5.03%) and geraniol (4.50%) were identified. The results highlighted that the enrichment with S. montana EO led to lower values of lipid oxidation indicators (K232, K270, peroxide value) and higher concentration of antioxidants (total phenols and pigments). In sum, the use of bioenrichment methods could be a sustainable solution for the promotion of the quality characteristics of EVOO in Algeria. Keywords: Bioenrichment, Satureja montana L., Essential oil, Extra virgin olive oil, Display, Quality stability.

Bioenrichment using Satureja montana L. essential oil for the prevention against photooxidation of flavored extra virgin olive oil during light display

Background: In response to consumer demand for novel and healthy foods, the presence in the market of olive oils (OOs) flavored with different plants, spices, herbs or fruits is increasingly common. All these flavoring agents have been used over the years due to its content in compounds with biological activities. Aim: The aim of this study was to investigate the potential role of the addition of S. montana EO at 100 ppm (0.01%, v/v), known for its high content of bioactive compounds, good flavor, and aroma in improving oxidative stability and quality profile of EVOO subjected to conditions causing accelerated oxidation (Light storage at 900 lux). Materials and methods: The S. montana EO chemical components were identified using Gas Chromatography–Mass Spectrometry (GC/MS). Enriched and non-enriched EVOO samples were examined as function of time (30, 60 and 9 days) of display for different quality indices. Results: Using GC/MS analysis of S. montana EO: thymol (28.36%), carvacrol (17.45%), p-cymene (10.91%), trans-caryophyllene (5.54%), ɤ-terpinene (5.03%) and geraniol (4.50%) were identified. The results highlighted that the enrichment with S. montana EO led to lower values of lipid oxidation indicators (K232, K270, peroxide value) and higher concentration of antioxidants (total phenols and pigments). In sum, the use of bioenrichment methods could be a sustainable solution for the promotion of the quality characteristics of EVOO in Algeria. ​Keywords: Bioenrichment, Satureja montana L., Essential oil, Extra virgin olive oil, Display, Quality stability.