bluuebunny/crossref_metadata_2025 huggingface dataset:
The exploration-exploitation trade-off in a foraging task is affected by mood-related arousal and valence
Authors: van Dooren Roel , de Kleijn Roy , Hommel Bernhard , Sjoerds Zsuzsika
Published: June 2021

The exploration-exploitation trade-off shows conceptual, functional, and neural analogies with the persistence-flexibility trade-off. We investigated whether mood, which is known to modulate the persistence-flexibility balance, would similarly affect the exploration-exploitation trade-off in a foraging task. More specifically, we tested whether interindividual differences in foraging behavior can be predicted by mood-related arousal and valence. In 119 participants, we assessed mood-related interindividual differences in exploration-exploitation using a foraging task that included minimal task constraints to reduce paradigm-induced biases of individual control tendencies. We adopted the marginal value theorem as a model-based analysis approach, which approximates optimal foraging behavior by tackling the patch-leaving problem. To assess influences of mood on foraging, participants underwent either a positive or negative mood induction. Throughout the experiment, we assessed arousal and valence levels as predictors for explorative/exploitative behavior. Our mood manipulation affected participants' arousal and valence ratings as expected. Moreover, mood-related arousal was found to predict exploration while valence predicted exploitation, which only partly matched our expectations and thereby the proposed conceptual overlap with flexibility and persistence, respectively. The current study provides a first insight into how processes related to arousal and valence differentially modulate foraging behavior. Our results imply that the relationship between exploration-exploitation and flexibility-persistence is more complicated than the semantic overlap between these terms might suggest, thereby calling for further research on the functional, neural, and neurochemical underpinnings of both trade-offs.
Maskulinitas dan Perempuan: Resepsi Perempuan terhadap Soft Masculinity dalam Variety Show
Authors: Kartika Sekar Hayu Rifna , Wirawanda Yudha
Published: June 2021

Produce 101 season 2 merupakan ragam hiburan dari Korea Selatan yang menampilkan gambaran maskulinitas yang berbeda. Definisi dominan maskulin adalah maskulin macho yang merupakan tampilan sosok laki-laki kekar serta memiliki sifat keras. Berbeda dengan macho, dalam ragam hiburan ini menyajikan tipe maskulinitas yang lebih lembut. Penelitian ini bertujuan untuk mencari tahu bagaimana khalayak memaknai soft masculinity dalam variety show. Penelitian ini menggunakan teori resepsi audiens oleh Stuart Hall. Metode penelitian menggunakan pendekatan deskriptif kualitatif dengan teknik pengumpulan data wawancara mendalam dan sampel lima perempuan usia 20, 21, dan 22 tahun. Hasil penelitian terkait soft masculinity, informan berada pada posisi yang menegosiasi. Informan menganggap laki-laki mempunyai sisi maskulin lembut selain konstruksi tipe maskulin tough atau macho. Informan menegosiasikan soft masculinity sebagai salah satu definisi maskulin. Soft masculinity dinilai tetap sebagai maskulin yang lebih menunjukkan sisi lembut. Soft masculinity dinegosiasikan sebagai konstruksi maskulin dan bukan suatu yang feminin. Informan berada pada posisi dominant reading terkait soft masculinity sebagai tren dan selera. Informan menerima soft masculinity sebagai suatu keunikan dan menjadi suatu selera maskulin. Informan sadar bahwa maskulinitas yang dibangun untuk publik menjadi salah satu dari produk budaya. Maskulin yang mereka minati adalah produk produsen budaya yang membentuk tren dan selera mereka.
Optimalisasi Model Strategi Public Relations Museum Penerangan dalam Membentuk Citra Publik
Authors: Saputra Novianti , Marta Rustono Farady
Published: June 2021

Di era globalisasi ini juga diikuti dengan perubahan makna yang terjadi salah satunya nama museum. Masyarakat kini banyak yang mengartikan Museum Penerangan merupakan museum yang berisikan lampu, maka dari itu untuk memperkenalkannya pada masyarakat dibutuhkan peran Public Relations sebagai jembatan antara organisasi dengan masyarakat. Penelitian ini bertujuan untuk menggali informasi terkait strategi Public Relations serta citra yang dibentuk oleh Museum Penerangan. Jenis pendekatan penelitian ini menggunakan deskriptif kualitatif dengan metode studi kasus. Subyek penelitian ini terdiri dari staf public relations, staf museum, duta museum, dan pengunjung. Pengumpulan data dilakukan dengan cara wawancara mendalam, observasi, dan dokumentasi. Hasil penelitian ini menunjukkan bahwa strategi Public Relations Museum Penerangan dengan melakukan optimalisasi strategi PENCILS (Publicity, Event, News, Community Involvement, Inform or Image, Lobbying and Negotiation, and Social Engagement) melalui Duta Museum. Dalam melakukan perencanaan strategi, Public Relations Museum Penerangan sudah cukup ideal sesuai dengan prinsip dari teori excellence.
India during Covid-19 Pandemic Agriculture Research in Resources
Authors: Madhavan S Azhagu , R Sripriya , R Priyadharshini
Published: June 2021

The duration of the lockdown measures led us to consider how potential food crops and agriculture play a vital role in this pandemic situation. Except the Health services and essential services, agriculture sector play a major role in feeding the large population of the country. (COVID–19) pandemic crises and prompts changes in paddy cultivation. At first, we study about the role of the paddy cultivation for human beings in the lockdown scenario and at second, it fully covered about the farmers and their challenges faced during the paddy cultivation in the lockdown period also it elaborates to their input access, labour facilities in this situation (Human Resources), market availability and these supply chain for paddy thenit’s byproducts. Also, it Prompts Changes in Paddy Cultivation and finally the study carried about the dynamic usage paddy by-products to improve the standard of living of the farmers which means mushroom cultivation, vermicomposting, ropes, packing material, pellets, paper making, mulching techniques, animal feeding, rice bran wax, industrial grade crude oil, husk briquettes and also it act as a carrier for biofertilizers organisms. Year by year the risks faced by Indian farmers keep aggravating in terms of low rainfall, price volatility and rising debts.
THE INFLUENCE OF BOARD CHARACTERISTICS AND STATE HOLDING ON CORPORATE SOCIAL RESPONSIBILITY DISCLOSURE, EVIDENCE FROM VIETNAMESE LISTED FIRMS
Authors: Nguyen Thi Lien Huong , Tran Nhat Minh , Vu Manh Chien
Published: June 2021

Analysing the nexus between board diversity, CEO power, state holding, and corporate social responsibility disclosure in an emerging country: Vietnam, where some listed firms are held significantly by the State, is the fundamental objective of this study. In order to achieve this goal, we employed regression analysis using panel data. While board diversity consists of board gender diversification and board independence and CEO (executive) power, consisting of executive duality, executive holding (ownership), and deputy CEO, and state ownership are explanatory variables, and CSR disclosure is a dependent variable. The sample contains of 166 Vietnamese listed firms at the Hanoi Stock Exchange (HNX) for 2014−2016. After performing regression analysis, the result revealed that the proportion of female directors, deputy CEO, and state holding had a significant correlation with CSR publication. In contrast, the proportion of independent directors, CEO duality, and CEO ownership was found to be insignificant. Our research adds to the research on firm governance and CSR in several approaches. First, the paper adds to the study on the advancement of research toward corporate social responsibility and firm governance and CEO features impress on it. Second, our research expands CSR literature in developing countries, which has not been treated in detail. Fourth, this research advances and adds literature to some theories, including agency theory and resource-based view theory.
How Cost Impacts Equitable Participation in Astronomy Outreach Events
Authors: Archipley Melanie , Dalgleish Hannah S.
Published: June 2021

The International Astronomical Youth Camp (IAYC) is an astronomy education outreach event with more than 50 yr of history and over 1700 unique participants from 81 nationalities. The International Workshop for Astronomy e.V. is the non-profit organization behind the IAYC, established in 1979 and based in Germany. The IAYC’s unprecedented longevity in a rapidly globalizing world has meant that financial inequities decreases the reach of the camp to people from the Global South compared to Global North countries. Though nationalities represented per camp has increased steadily since its inception, the share of participants from eastern Europe and Africa has dropped, while those from western Europe and North America have increased. This note examines how camp cost, location, and leadership affects nationality diversity among participants, and how astronomy outreach events must reckon with funding for less privileged participants with limited access to resources.
Chromosomal mapping of repetitive DNA in Melipona seminigra merrillae Cockerell, 1919 (Hymenoptera, Apidae, Meliponini)
Authors: Barbosa Ingrid Cândido de Oliveira , Schneider Carlos Henrique , Goll Leonardo Gusso , Feldberg Eliana , Carvalho-Zilse Gislene Almeida
Published: June 2021

MeliponaIlliger, 1806 is represented by 74 known species of stingless bees, distributed throughout the Neotropical region. Cytogenetically it is the most studied stingless bee genus of the tribe Meliponini. Member species are divided in two groups based on the volume of heterochromatin. This study aim was to analyze the composition and organization of chromatin of the stingless bee subspeciesMelipona seminigra merrillaeCockerell, 1919 using classical and molecular cytogenetic techniques, so contributing to a better understanding of the processes of chromosomal changes within the genus. We confirm thatM. seminigra merrillaehas a chromosome number of 2n = 22 and n = 11, results that differ from those reported for the genus in the absence of B chromosomes. The heterochromatic pattern revealed a karyotype composed of chromosomes with a high heterochromatin content, which makes it difficult to visualize the centromere. Silver nitrate impregnation (Ag-NOR) showed transcriptionally active sites on the second chromosomal pair. Staining of base-specific fluorophores DAPI-CMA3indicated a homogeneous distribution of intensely DAPI-stained heterochromatin, while CMA3markings appeared on those terminal portions of the chromosomes corresponding to euchromatin. Similar to Ag-NOR, fluorescence in situ hybridization (FISH) with 18S ribosomal DNA probe revealed distinct signals on the second pair of chromosomes. Microsatellite mapping (GA)15showed markings distributed in euchromatic regions, while mapping with (CA)15showed marking patterns in heterochromatic regions, together with a fully marked chromosome pair. Microsatellite hybridization, both in heterochromatic and euchromatic regions, may be related to the activity of transposable elements. These are capable of forming new microsatellites that can be dispersed and amplified in different regions of the genome, demonstrating that repetitive sequences can evolve rapidly, thus resulting in within-genus diversification.
Cytogenetic characterisation and chromosomal mapping of microsatellite and telomeric repeats in two gecko species (Reptilia, Gekkonidae) from Thailand
Authors: Thongnetr Weera , Aiumsumang Surachest , Kongkaew Rodjarin , Tanomtong Alonglod , Suwannapoom Chatmongkon , Phimphan Sumalee
Published: June 2021

Studies of chromosomes of Cyrtodactylus jarujini Ulber, 1993 and C. doisuthep Kunya et al., 2014 to compare microsatellite and TTAGGG sequences by classical and molecular techniques were conducted in Thailand. Karyological typing from a conventional staining technique of C. jarujini and C. doisuthep showed diploid chromosome numbers of 40 and 34 while the Fundamental Numbers (NF) were 56 in both species. In addition, we created the chromosome formula of the chromosomes of C. jarujini showing that 2n (40) = Lsm1 + Lsm2 + Lt3 + Mm1 + Mt4 + Sm2 + Sa2 + St5 while that of C. doisuthep was 2n (34) = Lsm3 + Lm2 + Lt3 + Mm1 + Mt2 + Sm4 + Sa1 + St1. Ag-NOR staining revealed NOR-bearing chromosomes in chromosome pairs 13 and 14 in C. jarujini, and in chromosome pairs 9 and 13 in C. doisuthep. This molecular study used the FISH technique, as well as microsatellite probes including (A)20, (TA)15, (CGG)10, (CGG)10, (GAA)10, (TA)15 and TTAGGG repeats. The signals showed that the different patterns in each chromosome of the Gekkonids depended on probe types. TTAGGG repeats showed high distribution on centromere and telomere regions, while (A)20, (TA)15, (CGG)10, (CGG)10, (GAA)10 and (TA)15 bearing dispersed over the whole genomes including chromosomes and some had strong signals on only a pair of homologous chromosomes. These results suggest that the genetic linkages have been highly differentiated between the two species.
Cloning and physical localization of male-biased repetitive DNA sequences in Spinacia oleracea (Amaranthaceae)
Authors: Zhou Jian , Wang Shaojing , Yu Li'ang , Li Ning , Li Shufen , Zhang Yulan , Qin Ruiyun , Gao Wujun , Deng Chuanliang
Published: June 2021

Spinach (Spinacia oleracea Linnaeus, 1753) is an ideal material for studying molecular mechanisms of early-stage sex chromosome evolution in dioecious plants. Degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) technique facilitates the retrotransposon-relevant studies by enriching specific repetitive DNA sequences from a micro-dissected single chromosome. We conducted genomic subtractive hybridization to screen sex-biased DNA sequences by using the DOP-PCR amplification products of micro-dissected spinach Y chromosome. The screening yielded 55 male-biased DNA sequences with 30 576 bp in length, of which, 32 DNA sequences (12 049 bp) contained repeat DNA sequences, including LTR/Copia, LTR/Gypsy, simple repeats, and DNA/CMC-EnSpm. Among these repetitive DNA sequences, four DNA sequences that contained a fragment of Ty3-gypsy retrotransposons (SP73, SP75, SP76, and SP77) were selected as fluorescence probes to hybridization on male and female spinach karyotypes. Fluorescence in situ hybridization (FISH) signals of SP73 and SP75 were captured mostly on the centromeres and their surrounding area for each homolog. Hybridization signals primarily appeared near the putative centromeres for each homologous chromosome pair by using SP76 and SP77 probes for FISH, and sporadic signals existed on the long arms. Results can be served as a basis to study the function of repetitive DNA sequences in sex chromosome evolution in spinach.
On the stability of two-dimensional nonisentropic elastic vortex sheets
Authors: Chen Robin Ming , Huang Feimin , Wang Dehua , Yuan Difan
Published: June 2021

We are concerned with the stability of vortex sheet solutions for the two-dimensional nonisentropic compressible flows in elastodynamics. This is a nonlinear free boundary hyperbolic problem with characteristic discontinuities, which has extra difficulties when considering the effect of entropy. The addition of the thermal effect to the system makes the analysis of the Lopatinski\begin{document}$ \breve{{\mathrm{i}}} $\end{document} determinant extremely complicated. Our results are twofold. First, through a qualitative analysis of the roots of the Lopatinski\begin{document}$ \breve{{\mathrm{i}}} $\end{document} determinant for the linearized problem, we find that the vortex sheets are weakly stable in some supersonic and subsonic regions. Second, under the small perturbation of entropy, the nonlinear stability can be adapted from the previous two-dimensional isentropic elastic vortex sheets [6] by applying the Nash-Moser iteration. The two results confirm the strong elastic stabilization of the vortex sheets. In particular, our conditions for the linear stability (1) ensure that a stable supersonic regime as well as a stable subsonic one always persist for any given nonisentropic configuration, and (2) show how the stability condition changes with the thermal fluctuation. The existence of the stable subsonic bubble, a phenomenon not observed in the Euler flow, is specially due to elasticity.
Dynamics of particles on a curve with pairwise hyper-singular repulsion
Authors: Hardin Douglas , Saff Edward B. , Shu Ruiwen , Tadmor Eitan
Published: June 2021

We investigate the large time behavior of \begin{document}$ N $\end{document} particles restricted to a smooth closed curve in \begin{document}$ \mathbb{R}^d $\end{document} and subject to a gradient flow with respect to Euclidean hyper-singular repulsive Riesz \begin{document}$ s $\end{document}-energy with \begin{document}$ s>1. $\end{document} We show that regardless of their initial positions, for all \begin{document}$ N $\end{document} and time \begin{document}$ t $\end{document} large, their normalized Riesz \begin{document}$ s $\end{document}-energy will be close to the \begin{document}$ N $\end{document}-point minimal possible energy. Furthermore, the distribution of such particles will be close to uniform with respect to arclength measure along the curve.
Concentration phenomena for magnetic Kirchhoff equations with critical growth
Authors: Ji Chao , Rădulescu Vicenţiu D.
Published: June 2021

In this paper, we study the following nonlinear magnetic Kirchhoff equation with critical growth

   \begin{document}$ \begin{align*} \left\{ \begin{aligned} &-\Big(a\epsilon^{2}+b\epsilon\, [u]_{A/\epsilon}^{2}\Big)\Delta_{A/\epsilon} u+V(x)u = f(|u|^{2})u+\vert u\vert^{4}u \quad \hbox{in }\mathbb{R}^3, \\ &u\in H^{1}(\mathbb{R}^{3}, \mathbb{C}), \end{aligned} \right. \end{align*} $\end{document}

where \begin{document}$ \epsilon>0 $\end{document} is a parameter, \begin{document}$ a, b>0 $\end{document} are constants, \begin{document}$ V:\mathbb{R}^{3}\rightarrow \mathbb{R} $\end{document} and \begin{document}$ A: \mathbb{R}^{3}\rightarrow \mathbb{R}^{3} $\end{document} are continuous potentials, and \begin{document}$ f: \mathbb{R}\rightarrow \mathbb{R} $\end{document} is a nonlinear term with subcritical growth. Under a local assumption on the potential \begin{document}$ V $\end{document}, combining variational methods, penalization techniques and the Ljusternik-Schnirelmann theory, we establish multiplicity and concentration properties of solutions to the above problem for \begin{document}$ \varepsilon $\end{document} small. A feature of this paper is that the function \begin{document}$ f $\end{document} is assumed to be only continuous, which allows to consider larger classes of nonlinearities in the reaction.
Time splitting combined with exponential wave integrator Fourier pseudospectral method for quantum Zakharov system
Authors: Zhang Gengen
Published: June 2021

In this paper we develop a time splitting combined with exponential wave integrator (EWI) Fourier pseudospectral (FP) method for the quantum Zakharov system (QZS), i.e. using the FP method for spatial derivatives, a time splitting technique and an EWI method for temporal derivatives in the Schrödinger-like equation and wave-type equations, respectively. The scheme is fully explicit and efficient due to fast Fourier transform. Numerical experiments for the QZS are presented to illustrate the accuracy and capability of the method, including accuracy tests, convergence of the QZS to the classical Zakharov system in the semi-classical limit, soliton-soliton collisions and pattern dynamics of the QZS in one-dimension, as well as the blow-up phenomena of QZS in two-dimension.
Functional inequalities involving nonlocal operators on complete Riemannian manifolds and their applications to the fractional porous medium equation
Authors: Roidos Nikolaos , Shao Yuanzhen
Published: June 2021

The objective of this paper is twofold. First, we conduct a careful study of various functional inequalities involving the fractional Laplacian operators, including nonlocal Sobolev-Poincaré, Nash, Super Poincaré and logarithmic Sobolev type inequalities, on complete Riemannian manifolds satisfying some mild geometric assumptions. Second, based on the derived nonlocal functional inequalities, we analyze the asymptotic behavior of the solution to the fractional porous medium equation, \begin{document}$ \partial_t u +(-\Delta)^\sigma (|u|^{m-1}u ) = 0 $\end{document} with \begin{document}$ m>0 $\end{document} and \begin{document}$ \sigma\in (0, 1) $\end{document}. In addition, we establish the global well-posedness of the equation on an arbitrary complete Riemannian manifold.
A novel quality prediction method based on feature selection considering high dimensional product quality data
Authors: Hu Junying , Qian Xiaofei , Pei Jun , Tan Changchun , Pardalos Panos M. , Liu Xinbao
Published: June 2021

Product quality is the lifeline of enterprise survival and development. With the rapid development of information technology, the semiconductor manufacturing process produces multitude of quality features. Due to the increasing quality features, the requirement on the training time and classification accuracy of quality prediction methods becomes increasingly higher. Aiming at realizing the quality prediction for semiconductor manufacturing process, this paper proposes a modified support vector machine (SVM) model based on feature selection, considering the high dimensional and nonlinear characteristics of data. The model first improves the Radial Basis Function (RBF) in SVM, and then combines the Duelist algorithm (DA) and variable neighborhood search algorithm (VNS) for feature selection and parameters optimization. Compared with some other SVM models that are based on DA, genetic algorithm (GA), and Information Gain algorithm (IG), the experiment results show that our DA-VNS-SVM can obtain higher classification accuracy rate with a smaller feature subset. In addition, we compare the DA-VNS-SVM with some common machine learning algorithms such as logistic regression, naive Bayes, decision tree, random forest, and artificial neural network. The results indicate that our model outperform these machine learning algorithms for the quality prediction of semiconductor.
A note on the paper "Sufficient optimality conditions using convexifactors for optimistic bilevel programming problem"
Authors: Gadhi Nazih Abderrazzak
Published: June 2021

In this work, some reasoning's mistakes in the paper by Kohli (doi:10.3934/jimo.2020114) are highlighted. Furthermore, we correct the flaws, propose a correct formulation of the main result (Theorem 5.1) and give alternative proofs.
Multiple patterns formation for an aggregation/diffusion predator-prey system
Authors: Fagioli Simone , Jaafra Yahya
Published: June 2021

We investigate existence of stationary solutions to an aggregation/diffusion system of PDEs, modelling a two species predator-prey interaction. In the model this interaction is described by non-local potentials that are mutually proportional by a negative constant \begin{document}$ -\alpha $\end{document}, with \begin{document}$ \alpha>0 $\end{document}. Each species is also subject to non-local self-attraction forces together with quadratic diffusion effects. The competition between the aforementioned mechanisms produce a rich asymptotic behavior, namely the formation of steady states that are composed of multiple bumps, i.e. sums of Barenblatt-type profiles. The existence of such stationary states, under some conditions on the positions of the bumps and the proportionality constant \begin{document}$ \alpha $\end{document}, is showed for small diffusion, by using the functional version of the Implicit Function Theorem. We complement our results with some numerical simulations, that suggest a large variety in the possible strategies the two species use in order to interact each other.
Vanishing viscosity for a $ 2\times 2 $ system modeling congested vehicular traffic
Authors: Coclite Giuseppe Maria , Nitti Nicola De , Garavello Mauro , Marcellini Francesca
Published: June 2021

We prove the convergence of the vanishing viscosity approximation for a class of \begin{document}$ 2\times2 $\end{document} systems of conservation laws, which includes a model of traffic flow in congested regimes. The structure of the system allows us to avoid the typical constraints on the total variation and the \begin{document}$ L^1 $\end{document} norm of the initial data. The key tool is the compensated compactness technique, introduced by Murat and Tartar, used here in the framework developed by Panov. The structure of the Riemann invariants is used to obtain the compactness estimates.
Combined effects of homogenization and singular perturbations: A bloch wave approach
Authors: Tewary Vivek
Published: June 2021

In this work, we study Bloch wave homogenization of periodically heterogeneous media with fourth order singular perturbations. We recover different homogenization regimes depending on the relative strength of the singular perturbation and length scale of the periodic heterogeneity. The homogenized tensor is obtained in terms of the first Bloch eigenvalue. The higher Bloch modes do not contribute to the homogenization limit. The main difficulty is the presence of two parameters which requires us to obtain uniform bounds on the Bloch spectral data in various regimes of the parameter.
Annotated check-list of Pteromalidae (Hymenoptera: Chalcidoidea) of Morocco. Part II.
Authors: Kissayi Khadija , Mitroiu Mircea-Dan , Rohi Latifa
Published: June 2021

En esta segunda parte, presentamos la subfamilia Pteromalinae en Marruecos, que incluye 86 especies pertenecientes a 50 géneros. Quince géneros y 37 especies se enumeran por primera vez en la fauna marroquí, de las cuales 9 han sido recientemente identificadas, 24 se han encontrado en la bibliografía y 4 están depositadas en museos de historia natural. Se proporciona una lista actualizada de especies marroquíes, incluida su distribución por regiones, su distribución general y sus huéspedes.
Impact of fibre incorporation and compaction method on properties of pervious concrete
Authors: Juradin S. , Netinger-Grubeša I. , Mrakovčić S. , Jozić D.
Published: June 2021

This paper deals with the possibility of the improvement of pervious concrete properties by incorporation of different types of fibres and studies the effect of short duration vibration of pervious concrete properties in comparison with compaction with wooden lath and hammer. Ten mixtures of pervious concrete were prepared, five of which were compacted with wooden lath and hammer and five by short duration vibration. Density, porosity, permeability and mechanical properties were tested for in hardened pervious concrete specimens. It was concluded that mixtures compacted by short duration vibration had better mechanical properties due to the formation of a viscous layer at the contact surface between the aggregate grain and the cement matrix during the compaction, as well as pore-related properties. The addition of fibres negatively affected porosity and permeability but generally improved mechanical properties of concrete. The positive effect of fibre addition was more emphasised in cases of vibrated mixtures.
Influence of citric acid on the fire behavior of gypsum coatings of construction and structural elements
Authors: Castellón F.J. , Ayala M. , Flores J.A. , Lanzón M.
Published: June 2021

To improve the workability in gypsum plasters, additives are sometimes used, including citric acid, which provides acceptable setting times for low w/g ratios, maximizing the mechanical properties of the material. The influence of citric acid on the fire response of gypsum coatings is not well known, and so our aim was to analyze the effects that citric acid produces on the behavior of gypsum plasters exposed to fire. Temperature measurements were made with sensors and thermal imaging cameras while other instrumental techniques, including SEM, XRD and TG, were used to characterize the microstructure and composition of gypsum materials subjected to the action of fire. The fire had a greater effect on gypsum plasters containing citric acid as revealed by the cracking patterns and heat propagation profiles observed. Likewise, micro-cracks were observed in gypsum specimens, containing and non-containing citric acid, exposed to fire. In all cases, the alterations were consistent with the temperature profiles and chemical composition of the faces whether exposed to fire or not.
The Effect of Digital Technology Integration on Students’ Academic Performance through Project-Based Learning in an E-learning Environment
Authors: Al-Abdullatif Ahlam Mohammed , Gameil Azza Ali
Published: June 2021

This study aimed to develop a model to examine how digital technology integration contributes to the enhancement of students’ academic performance through project-based learning (PBL) amongst undergraduates in higher education. In this study, the technology acceptance model (TAM) was used as the basic model to explore the digital technology environment in terms of the perceived usefulness, perceived ease of use and attitude towards integrating digital technology and the influence of these factors on undergraduates' learning engagement and academic performance within PBL. Therefore, this study proposed a model comprising factors that assist in addressing the study objective. As the main data collection method, a questionnaire was developed to obtain relevant information regarding digital technology acceptance, PBL, students' learning engagement and academic performance. The study sample comprised 185 undergraduate students who were enrolled in a course that utilised PBL. A quantitative research method via structural equation modelling (SEM) was used to analyse the data. The finding suggested that TAM-related factors and students’ learning engagement positively affect their academic performance when digital technology is integrated into the PBL environment.
The Urgency of Digital Literacy for Generation Z Students in Chemistry Learning
Authors: Dewi Citra Ayu , Pahriah Pahriah , Purmadi Ary
Published: June 2021

Chemistry learning is faced with problems that emphasize students' difficulty in learning the basic chemistry concepts to become increasingly difficult and less meaningful. Digital literacy can understand chemistry concepts and develop critical thinking skills because digital literacy emphasizes reading, writing, understanding, evaluating, communicating, and using the information in different formats. This research aims to determine the role and urgency of digital literacy for generation Z students in chemistry learning. This research is descriptive qualitative research. The research subjects were chemistry education students of FSTT of Universitas Pendidikan Mandalika. In this study, there were two types of data; primary and secondary data. The primary data was collected through direct observation and interviews. Secondary data was collected through the literature review. The results showed that digital literacy is needed in chemistry learning by focusing on the needs of Generation Z students in accessing the internet as a medium to promises ease of community connectivity, starting from how to communicate, collaborate, be creative, solve problems, make decisions, and consume information. In chemistry learning, digital technology can help improve chemistry teaching quality in technical, cognitive, and social aspects. Also, digital technology has become necessary in chemistry learning because it can help students learn better with various ICT-enabled features that can motivate understanding of chemistry concepts and reduce cognitive memory load when studying ICT-based chemistry. Thus, digital literacy is urgent for Generation Z students in chemistry learning.
Genetic Algorithm for Solving Multi-Objective Optimization in Examination Timetabling Problem
Authors: Ngo Son Tung , Jaafar Jafreezal B , Aziz Izzatdin Abdul , Nguyen Giang Hoang , Bui Anh Ngoc
Published: June 2021

Examination timetabling is one of 3 critical timetabling jobs besides enrollment timetabling and teaching assignment. After a semester, scheduling examinations is not always an easy job in education management, especially for many data. The timetabling problem is an optimization and Np-hard problem. In this study, we build a multi-objective optimizer to create exam schedules for more than 2500 students. Our model aims to optimize the material costs while ensuring the dignity of the exam and students' convenience while considering the rooms' design, the time requirement of each exam, which involves rules and policy constraints. We propose a programmatic compromise to approach the maximum tar-get optimization model and solve it using the Genetic Algorithm. The results show the effectiveness of the introduced algorithm.
Teachers’ Perception on the Benefits of Using Online Resources
Authors: Shatri Kyvete , Buza Kastriot , Bunjaku Florent
Published: June 2021

This research elaborates the perception of the teachers in relation to the benefits of using online resources in their educational activities, respectively the impact of the utilization of the platform “School Me” in the teaching and learning pro-cess. This was a longitudinal research and it included teachers of various sub-jects. The key research question tends to address the teachers’ insight for the benefits of using online resources. Taking into account that the nature of this study is of the evaluative character, a mixed methodology has been implemented by using questionnaires and interviews in order to study and analyze the problem focus. The results show that teachers have a positive attitude towards usage of the platform in their teaching, which also influences for their lessons to become more attractive and comprehensive for the students and easier for the teachers. As far as the usage of online resources for the students’ learning concerns, the findings of the performed research indicate a positive attitude of the teachers in schools for the affirmative impact that the usage of online resources has for the students’ learning. This research also indicated that there are still technical prob-lems present which in many cases hindered the utilization of the online re-sources.
Evaluation of Factors Affecting Student Participation in Peer-Assisted English Learning Based on Online Education Platform
Authors: Hu Hong , Wang Xiuli , Zhai Yuhui , Hu Jian
Published: June 2021

Through a questionnaire survey, this study explored the factors affecting student participation in peer-assisted English learning (PAEL) based on online education platforms. Specifically, the authors constructed the system of PAEL contents, analyzed the online PAEL behaviors of students, and evaluated the student participation in online PAEL from both surface participation and deep participation. On this basis, the influencing factors of student participation in online PAEL were evaluated thoroughly. In the end, several countermeasures were presented to solve the problems with student participation in online PAEL. The results show that: the online PAEL face such problems like low-level knowledge structure and poor interaction quality, weak intensity of interaction, and inactive atmosphere of collaboration; In general, the students are not actively participating in online PAEL; the student participation in online PAEL is greatly affected by teachers, students, teaching contents, and online education platforms; the low participation in online PAEL mainly arises from the weak motives of students for online PAEL, the inadequate teaching design and supervision of teachers, and the imperfect functions of online education platform. The research enriches the theoretical and practical results on the factors affecting student participation in online PAEL.
A Software Security Optimization Architecture (SoSOA) and its Adaptation for Mobile Applications
Authors: Abozeid Amr , AlHabshy AbdAllah Adel , ElDahshan Kamal
Published: June 2021

Security attacks become daily news due to an exposure of a security threat in a widely used software. Taking software security into consideration during the analysis, design, and implementation phases is a must. A software application should be protected against any security threat such as unauthorized distribution or code retrieval. Due to the lack of applying a software security standard architecture, developers may create software that may be vulnerable to many types of security threats. This paper begins by reviewing different types of known software security threats and their countermeasure mechanisms. Then, it proposes a new security optimization architecture for software applications. This architecture is a step towards establishing a standard to guarantee the software's security. Furthermore, it proposes an adapted software security optimization architecture for mobile applications. Besides, it presents an algorithmic implementation of the newly proposed architecture, then it proves its security. Moreover, it builds a secure mobile application based on the newly proposed architecture.
Les déterminants des compétences sociales des élèves de cycle III
Authors: Fanchini Agathe
Published: June 2021

Les différences de réussite à l’école primaire traditionnellement étudiées par les chercheurs en éducation peuvent être analysées à la lumière des compétences et plus particulièrement des compétences sociales. Champ théorique encore en construction, les compétences sociales deviennent tout de même un « incontournable » pour les acteurs du système éducatif et pour la recherche en sciences de l’éducation. Par une approche pluridisciplinaire, cet article propose d’étudier quels sont les déterminants des compétences sociales à l’aide d’indicateurs sociodémographiques et scolaires largement empruntés dans les modèles d’explication des différences de réussite, auxquels sont associées des mesures de l’image de soi, du névrosisme et du rapport à l’école. Ces dimensions participent en effet à la socialisation et au développement des compétences de l’élève. Un outil de mesure validé des compétences sociales et un échantillon de 855 élèves de cycle III permettent de comprendre par exemple la réussite des filles à l’école ou le poids de l’image de soi dans le développement des compétences sociales interindividuelles et intra-individuelles. Les résultats explicatifs des déterminants des compétences sociales (elles-mêmes explicatives de la réussite) peuvent alors ouvrir le débat sur les différences de réussite scolaire à l’école en redessinant le schéma classique du lien direct entre les caractéristiques des élèves et leur réussite, par l’effet intermédiaire des compétences sociales.
Migration of Violence, Violence in migration. The Vulnerabilities of Central American Populations Going North
Authors: Faret Laurent
Published: June 2021

Central American migratory journeys take place in risky geographical and socio-political spaces, where situations involving danger and vulnerability take many forms. Based on observation of experiences and contexts of mobility, the author examines expressions of violence as one of the motives for migration, as a constraint affecting the implementation of migration projects and finally, as an effect of migration policies of containment. He postulates that forms of violence are intertwined, often cumulative, and that their persistence constitutes a component of migration phenomena in the region today. The article aims to examine the ways in which a ‘continuum of violence’ creates marginal status and generates situations that, in turn, fuel forms of vulnerability where risks are trivialised, while the migratory presence is socially, legally and politically undervalued and rendered invisible.
Teaching With the 21st-Century Competencies
Authors: Calmer Joseph Malcolm
Published: June 2021

Teaching in the 21st century is hard, complex work. There are many resources available to use for teachers and organizations. The teacher needs to focus and only using instructional materials and practices that are effective and maximize learning. The P21 Framework allows for teachers to align and produce curricula and materials that are high leverage in nature and produce global competencies. Through the use and implementation of philosophy and psychology, a teacher can incorporate their own 21st century skills and practice to produce 21 century learners.
Digitalization of K-12 Teacher Training
Authors: Forrest Linda M.
Published: June 2021

This chapter explores the need for reform in teacher training and professional development of K-12 teachers. Barriers caused by traditional models of professional development courses will be addressed. Information from a phenomenological study investigating teachers' attitudes, perceptions, and motivations regarding blended professional development will provide guidance and insights on the value of blended learning methods. An author-created theoretical framework for blended online professional development, which combines the convenience of online learning with face-to-face learning communities, will be shared. The chapter concludes with recommendations for school system leaders on how to meet the needs and desires of teachers, as well as for the digitalization of teacher training to reform professional development practices and promote 21st century skills for both staff and students.
Leveraging Educational Technology to Meet the Needs of 21st Century Learners
Authors: McWhorter Gregory R.
Published: June 2021

This chapter is on leveraging technology for education and includes models for adoption as well as possible barriers. The chapter includes information on how educators need to conduct an internal audit for personal bias, attitude, and perceptions. The idea of adopting a growth mindset when using technology in education is explored. Questions regarding why and how technology should be integrated into education are analyzed. Technology integration frameworks are compared, and some digital applications are discussed. Social equity and access, along with culturally relevant teaching strategies, are examined as to why and how these may be employed to close the digital divide for all students. There are sections detailing the implications for educators and administrators.
Innovative Instructional Methods Integrating 21st-Century Competencies in Mathematics Education
Authors: Powell Elizabeth
Published: June 2021

Rich exploratory, visual tasks foster opportunities conversations in math class. Clear mental models build the foundation for deeper conversations and foster a class culture where all voices are heard by providing opportunities to take risks and reflecting on beliefs about student ability. Teachers and students can learn the value of engaging with different perspectives. Reflecting on instruction for teachers and learning for students improves retention and understanding. A teacher's role is as facilitator and modeling behavior and communication. Professional development and frameworks are needed to adopt the competencies effectively. Researchers evaluating efficacy of rich tasks and 21st century competencies must reexamine beliefs about ability, consider the impact of societal barriers on student learning, and focus on how instruction can adapt to be more effective for all learners. More research in all of these areas is needed.
Breaking the Shell: Labour Force Participation among Married Women by Ethnic Sub Groups in Sri Lanka
Authors: Siyama M.A.F. , Samaraweera G.R.S.R.C.
Published: June 2021

Gender equality in decent work and economic decision-making are still not ensured in Sri Lanka although it ensures gender parity in both education and health care. Marriage, culture, and traditional values challenge the human right of independent economic decision making among women in developing countries. The main objective of this study is to explore the ethno-specific drivers of Labor Force Participation among married women in Sri Lanka to capture deep insights into the ethno-cultural picture of the issue. Secondary data were used from the Sri Lankan Labour Force Survey 2018 including 14,533 married females and four Binary Logistic Regression models were derived for female labour force participation among ethnic subgroups. The analysis concludes that ethnicity plays a major role in the career contribution of married females in the country. Concerning married Sinhalese women, the married women representing the Sri Lankan/Indian Tamils are more probable to join in the labour market, while married women representing the Moors are less probable to participate as they are highly intertwined to traditional and cultural boundaries. Employment and occupational sector of husband, availability, and age of children, family income, age, residential sector, province, disability, vocational training, and digital literacy are the key drivers of career contribution of married women that reflect distinctive impacts on different ethnic groups. Finally, the study proposed possible policy recommendations for encouraging Female Labour Force participation by addressing the ethno-marital issues.
Role of Mobile Technology on Business Opportunism and Performance of SMEs in Sri Lanka
Authors: Ranatunga R.V.S.P.K. , Priyanath H.M.S. , Megama R.G.N.
Published: June 2021

The study empirically examined how the use of mobile technology affects the opportunism and business performance of Small and Medium-sized Enterprises (SMEs) in Sri Lanka. The Partial Least Squares-Structural Equation Modelling (PLS-SEM) was utilized to analyze the data that was collected from 400 SMEs by utilizing a structured questionnaire having face-to-face and telephony inter-views. Results revealed that mobile technology generates a significant positive effect on business performance and, consequently, a negative effect on opportunism while opportunism makes a negative impact on the business performance of SMEs. Simultaneously, the study revealed that opportunism considerably interposes in the relationship between mobile technology and SME business performance. Finally, the study has made a strong recommendation to strengthen the use of mobile technology and its applications which highly relate to solving the issues faced by SMEs in the current imperfect market mechanism.
Detection ofAdelges tsugae(Hemiptera: Adelgidae) wool using Velcro-covered balls
Authors: Fidgen Jeffrey G. , Whitmore Mark C. , MacQuarrie Chris J.K. , Turgeon Jean J.
Published: June 2021

Adelges tsugaeAnnand (Hemiptera: Adelgidae), a nonindigenous insect pest of hemlock (Tsugaspp.) (Pinaceae) in eastern North America, spends most of its life cycle within an ovisac, which resembles a woolly white mass on twigs. We evaluated the probability of detecting adelgid wool with Velcro®-covered balls when taking an increasing number of samples per tree (field sampling) and number of trees per simulated stand. We examined the relationship between the detection of adelgid wool using this technique and the incidence ofA. tsugae-infested twigs by sampling lower-crown branch tips of the same trees. We found that the probability of detecting wool with ball sampling increased with number of ball samples per tree, with number of trees per simulated stand, and with increasing incidence of ovisacs in the lower crown. When sampling an individual tree, we found that 20 ball samples per tree achieved a targeted precision level of 0.75, but when sampling a stand, we found that 10 ball samples per tree took the least time for the range of simulatedA. tsugaeinfestations we tested. These sample sizes are recommended for detection ofA. tsugaeinfestations on an individual tree and in a hemlock stand.