bluuebunny/crossref_metadata_2025 huggingface dataset:
Another Case Of Physical Abuse In Childhood Between Age 7-11 And Alice In Wonderland-Like Seizures Retrospectively Described By A 45 Years-Old Man In Detail
Authors: Bittmann Stefan
Published: May 2021

The phenomenon of Alice in Wonderland Syndrome is not considered a disease in its own right but usually occurs as an accompanying symptom of a migraine attack or as a precursor of an epileptic seizure in the form of an aura with pronounced visual perceptual disturbances [1]. However, an Alice in Wonderland syndrome can also be caused by the Epstein-Barr virus, influenza virus [18], drugs [3] or encephalitis [2]. The term "Alice in Wonderland syndrome" was named after the children's book Alice in Wonderland by Lewis Carroll and coined by John Todd as a possible, but not essential, concomitant of migraine and epilepsy [1]. Carroll suffered from migraines himself; it is believed that his experiences with the condition served as inspiration for the hallucination-like effects described in his work [1]. In addition, Carroll's narrative has been discussed as a description of a trip following consumption of mind-altering drugs. In one of the most famous sequences in the book, Alice changes size by biting off pieces from different sides of a mushroom. However, there is no evidence of drug use by Lewis Carroll. Alice in Wonderland syndrome results in changes in the perception of one's surroundings [6,7]. These changes include both micropsia and macropsia (everything appears reduced or enlarged), as well as altered auditory perception, altered tactile perception, an altered sense of time. The syndrome is particularly common in children. Attacks are often shorter and may also be completely painless, although accompanying symptoms such as nausea, vomiting, and sensitivity to light and sound is more pronounced. Neurological deficits may occur so that the affected child begins to hallucinate. He or she perceives his or her body as larger or smaller and/or begins to see "fantastic images“. The changes in perception can severely affect affected individuals, causing them to become disoriented and "unable to find their way around." In extreme cases, falls and other accidents may occur. The perceptual disturbances can lead to Alice in Wonderland syndrome being confused with other mental disorders or misinterpreted as "craziness". The primary focus is the treatment of the underlying condition, such as symptomatic treatment of migraine. Recent publications shed light on sexual abuse in childhood as the origin of AIWS-like visual disturbances [4,5].
The role of the Pompeiu-Hausdorff metric in fixed point theory
Authors:   DEPARTMENT OF MATHEMATICS AND COMPUTER SCIENCE NORTH UNIVERSITY OF BAIA MARE VICTORIEI 76, 430072 BAIA MARE, ROMANIA E-mail address: vberinde@ubm.ro, BERINDE VASILE ,   vasile berinde@yahoo.com, PACURAR MADALINA ,   DEPARTMENT OF STATISTICS, ANALYSIS AND MATHEMATICS FACULTY OF ECONOMICS AND BUSSINESS ADMINISTRATION BABES-BOLYAI UNIVERSITY OF CLUJ-NAPOCA 56-60 T. MIHALI ST., 400591 CLUJ-NAPOCA, ROMANIA E-mail address: madalina.pacurar@econ.ubbcluj.ro
Published: May 2021

The main aim of this note is to highlight the role of the Pompeiu-Hausdorff metric in fixed point theory and, subsidiarily, to touch some issues related to the history of this fundamental concept in modern mathematics. This will allow us to conclude that what is nowadays almost generally called Hausdorff metric (distance) and very seldom Hausdorff-Pompeiu metric (distance) or Pompeiu-Hausdorff metric (distance), should be fairly and correctly named Pompeiu-Hausdorff metric (distance).
Why using symbolic computation for proving the convergence of iterative methods?
Authors:   DEPARTMENT OF MATHEMATICS AND COMPUTER SCIENCE FACULTY OF SCIENCES NORTH UNIVERSITY CENTER AT BAIA MARE TECHNICAL UNIVERSITY OF CLUJ-NAPOCA VICTORIEI 76, 430122 BAIA MARE, ROMANIA E-mail address: ardelean g@yahoo.com, ARDELEAN GHEORGHE , BALOG LASZLO ,   DEPARTMENT OF MATHEMATICS AND COMPUTER SCIENCE FACULTY OF SCIENCES NORTH UNIVERSITY CENTER AT BAIA MARE TECHNICAL UNIVERSITY OF CLUJ-NAPOCA VICTORIEI 76, 430122 BAIA MARE, ROMANIA E-mail address: balog 58@yahoo.com
Published: May 2021

In [YoonMe Ham et al., Some higher-order modifications of Newton’s method for solving nonlinear equations, J. Comput. Appl. Math., 222 (2008) 477–486], some higher-order modifications of Newton’s method for solving nonlinear equations are presented. In [Liang Fang et al., Some modifications of Newton’s method with higher-order convergence for solving nonlinear equations, J. Comput. Appl. Math., 228 (2009) 296–303], the authors point out some flaws in the results of YoonMe Ham et al. and present some modified variants of the method. In this paper we point out that the paper of Liang Fang et al. itself contains some flaw results and we correct them by using symbolic computation in Mathematica. Moreover, we show that the main result in Theorem 3 of Liang Fang et al. is wrong. The order of convergence of the method is’nt 3m+2, but is 2m+4. We give the general expression of convergence error too.
Remarks on notions of µ ∗ -open sets
Authors:   DEPARTAMENTO DE MATEMATICAS UNIVERSIDAD DE ORIENTE CUMANA VENEZUELA, AND UNIVERSIDAD DEL ATLANTICO FACULTAD DE CIENCIAS BASICAS BARRANQUILLA, COLOMBIA E-mail address: carpintero.carlos@gmail.com, CARPINTERO CARLOS , ROSAS ENNIS ,   DEPARTAMENTO DE MATEMATICAS UNIVERSIDAD DE ORIENTE CUMANA VENEZUELA, AND UNIVERSIDAD DEL ATLANTICO FACULTAD DE CIENCIAS BASICAS BARRANQUILLA, COLOMBIA E-mail address: ennisrafael@gmail.com, SALAS MARGOT ,   DEPARTAMENTO DE MATEMATICAS UNIVERSIDAD DE ORIENTE CUMANA VENEZUELA, AND UNIVERSIDAD DEL ATLANTICO FACULTAD DE CIENCIAS BASICAS BARRANQUILLA, COLOMBIA E-mail address: salasbrown@gmail.com, BLANCO IVAN ,   DEPARTAMENTO DE CIENCIAS BASICAS UNIVERSIDAD DE LA COSTA-CUC BARRANQUILLA, COLOMBIA E-mail address: ivablanram@gmail.com, POLO MARTHA ,   DEPARTAMENTO DE CIENCIAS BASICAS UNIVERSIDAD DE LA COSTA-CUC BARRANQUILLA, COLOMBIA E-mail address: marthainesmp@gmail.com
Published: May 2021

The purpose of this paper is to show that the construction leading from a generalized topology µ and a hereditary class of sets H to another generalized topology µ ∗ remains valid, together with a lot of properties, if the generalized topology µ and the hereditary class H are replaced by arbitrary classes of subsets.
Neutrophil recovery with or without G-CSF in non M3 AML patient with DA 3+7 protocol
Authors: Islam Gazi Yeasinul , Khan Mohiuddin Ahmed , Akter Mafruha , Rahman H N Ashiqur , Ibrahim Md. , Masud Md. Adnan Hasan , Farhad Md. Nurul , Rabby A S M Tariqur
Published: May 2021

Background: Induction of acute myeloid leukaemia is associated with a high incidence of treatment related mortality mostly due to neutropenia related infections. This study primarily analyses the duration of neutrophil recovery with or without G-CSF during induction with DA 3+7 in non M3 AML patients. This study also evaluates role of G-CSF in duration febrile neutropenia, hospital stay, total blood products transfusion, total number of used injectable antibiotics and remission status. Methods: It was a Quasi Experimental - Non-Randomized Controlled Trail. There were two groups a) Case = Patients receiving G-CSF b) Control= Patients not receiving G-CSF. Sampling was purposive sampling. Results:  50 patients in two group, G-CSF group (n=25) and Control group (No G-CSF) (n=25) participated in this study. Among them 54% was female and 46% was male. Median age of the participants was 28 years. Neutrophil recovery duration in G-CSF group Vs Control group showed 22.64 Vs 24.64 days (p value 0.003). Duration of febrile neutropenia in G-CSF group Vs Control group showed 11.24 Vs 13.56 days (p value 0.038). Duration of hospital stay in G-CSF group Vs Control group showed 23.64 Vs 25.76 days (p value 0.002). Total number of blood and blood product transfusion in G-CSF group Vs Control group showed 3.80 Vs 3.88 (p value 0.597). Total number of injectable antibiotics in G-CSF group Vs Control group showed 2.72 Vs 3.12 days (p value 0.169). In G-CSF group 22 (88%) and in Control group 23 (92%) were in complete remission (p value 0.637). Conclusions: G-CSF significantly reduces the duration of neutropenia (p value 0.003), febrile neutropenia (p value 0.038) and hospital stay (p value 0.002) after induction with DA 3+7. This may cause reduction in treatment cost and sepsis related mortality. G-CSF can’t significantly reduce use of blood products (p value 0.597) and injectable antibiotics (p value 0.169) after induction with DA 3+7. G-CSF does not affect morphological remission status (p value 0.637) after induction with DA 3+7.
Transition Metal-Free Intramolecular Friedel-Crafts Reaction by Alkene Activation: A Method for the Synthesis of Some Novel Xanthene Derivatives
Authors: Yıldız Tülay , Baştaş İrem , Başpınar Küçük Hatice
Published: May 2021

In this work, new derivatives (substituted 9-methyl-9-arylxanthenes) of xanthene compounds (5a-5l) of possible biological significance were synthesized by developing a new synthesis method. In order to obtain xanthene derivatives, the original alkene compounds to be used as the starting point were synthesized in four steps using appropriate reactions. Cyclization reaction by intramolecular Friedel-Crafts alkylation was carried out in order to synthesize the desired xanthene derivatives using the alkenes as starting compounds. Intramolecular Friedel-Crafts reaction was catalyzed by trifluoroacetic acid (TFA) and provided some novel substituted 9-methyl-9-arylxanthenes with good yields at room temperature within 6–24 hours. As a result, an alkene compound was used for activation with TFA in the synthesis of xanthene through intramolecular Friedel-Crafts alkylation for the first time.
Öğretmen Adaylarının Dijital Etik Düzeylerinin Bazı Değişkenler Açısından İncelenmesi
Authors: ÖZBAY Özkan , DOĞAN Uğur , YILDIZ Esma , SEFEROĞLU Süleyman Sadi
Published: May 2021

Bilişim teknolojileri insanlara birçok fırsat sunmakla birlikte önümüzdeki yıllarda etkileri daha da belirgin hâle gelebilecek bazı etik sorunları da ortaya çıkarmaktadır. Bu nedenle gelecek nesilleri yarına hazırlamada önemli bir rol üstlenen öğretmenlerin, dijital etik konusunda yeterli bilgiye sahip, bilişim teknolojilerini etik kullanan iyi birer dijital vatandaş olmaları gerekmektedir. Bu araştırmada öğretmen adaylarının bilişim teknolojilerini etik kullanım düzeyleri bazı değişkenler açısından incelenmiştir. Araştırma kesitsel tarama modelinde desenlenmiştir. Araştırmanın çalışma grubunu farklı devlet üniversitelerinin eğitim fakültelerinde öğrenim gören toplam 221 öğretmen adayı oluşturmaktadır. Araştırmada veri toplama aracı olarak “Kişisel Bilgi Formu” ve “Bilgi ve İletişim Teknolojileri Etiği Ölçeği” kullanılmıştır. Verilerin analizi sonucunda öğretmen adaylarının bilişim teknolojilerini etik kullanım düzeylerinin; cinsiyet, bölüm, internet kullanma becerisi, bilişim etiğine ilişkin daha önce ders, kurs veya seminere katılma durumu, bilişim suçları ve cezalarına ilişkin bilgi düzeyine göre istatistiksel olarak anlamlı bir farklılık gösterdiği tespit edilmiştir. Araştırma sonucuna göre öğretmen adaylarının bilişim teknolojilerini etik kullanım düzeylerinin yüksek olduğu sonucuna ulaşılmıştır.
TD 2631 - Expansão da Educação Superior e Progressividade do Investimento Público
Authors: Costa Joana , Waltenberg Fábio , Silveira Fernando Gaiger , Costa Roberta
Published: May 2021

Neste trabalho, descrevem-se as mudanças no acesso à educação superior e no perfil do seu alunado, bem como a evolução do impacto redistributivo do investimento em educação superior pública, durante o período 2001-2015, com dados da Pesquisa Nacional por Amostra de Domicílios do Instituto Brasileiro de Geografia e Estatística (PNAD/ IBGE) e do Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira do Ministério da Educação (Inep/MEC). A expansão da educação superior caminhou rumo a uma maior democratização do acesso especialmente nas universidades públicas e no período 2005-2015. Como resultado, uma proporção maior do investimento do governo em educação superior pública passou a alcançar os estratos mais pobres da sociedade e, além disso, esse nível de educação vem deixando de contribuir para a concentração da renda.
TD 2634 - Indutores do Gasto Direto do Ministério da Saúde em Medicamentos (2010-2019)
Authors: Vieira Fabiola Sulpino
Published: May 2021

O objetivo deste texto é analisar a contribuição dos principais indutores do gasto direto do Ministério da Saúde (MS) em medicamentos que integram a lista dos componentes da assistência farmacêutica (AF) no período de 2010 a 2019. Foram utilizados dados de aquisições constantes do Sistema Integrado de Administração de Serviços Gerais (Siasg). Os medicamentos foram categorizados segundo o sistema de classificação ATC/DDD (Anatomical Therapeutic Chemical Classification System/defined daily doses) da Organização Mundial da Saúde (OMS). As unidades físicas de compra dos produtos foram transformadas em número de doses diárias definidas (DDD) para cada fármaco e o preço unitário foi convertido para preço por DDD. Com o suporte do software RStudio versão 1.3.1056 e do pacote estatístico IndexNumR, mensurou-se a contribuição dos principais indutores do gasto em medicamentos: preço, quantidade e resíduo (escolhas terapêuticas). Os resultados mostram grande variação do gasto do MS em medicamentos da lista dos componentes da AF no período de 2010 a 2019, com maior ou menor contribuição de cada indutor principal na oscilação observada. Contudo, chama a atenção a redução do gasto em alguns anos, induzida principalmente pela diminuição da quantidade de medicamentos adquirida em dois anos consecutivos, o que pode resultar em queda da disponibilidade desses produtos no Sistema Único de Saúde (SUS).
TD 2636 - Crescimento Econômico e a Associação Espacial de Clusters Municipais no Estado de Goiás: 2002-2016
Authors: Queiroz Antonio Marcos de , Pires Murilo José de Souza
Published: May 2021

O objetivo deste texto é analisar o crescimento econômico dos municípios goianos, nos anos de 2002, 2010 e 2016, observando a dependência e a associação espacial em tais municípios. A metodologia contempla a utilização da estatística espacial, especificamente a identificação de autocorrelação dos dados espacialmente, bem como a formação de clusters municipais espaciais. Os resultados apontam que nos clusters alto-alto (AA)/ baixo-baixo (BB) estão os municípios com crescimento do produto interno bruto (PIB) per capita maior/menor do que a média do estado. Estes clusters estão localizados: i) nas microrregiões do sudoeste de Goiás, em Meia Ponte, no Vale do Rio dos Bois e em Catalão (clusters AA); e ii) nas microrregiões de Porangatu, no entorno de Brasília, em Ceres, em Vão do Paranã e na Chapada do Veadeiros (clusters BB). Conclui-se que existe um padrão bastante desigual e heterogêneo no tempo e na distribuição espacial do crescimento econômico em Goiás e que a identificação espacial de clusters de menor taxa de crescimento do PIB per capita permite a elaboração de políticas públicas. Isso faz com que o estado possa atrair novos investimentos na tentativa de mitigar as desigualdades regionais e dinamizar os municípios de baixo crescimento econômico.
TD 2641 - Uma Análise da Contribuição do Fundeb sobre a Qualidade da Educação Pública dos Municípios Brasileiros
Authors: Becker Kalinca Léia
Published: May 2021

Este estudo analisou o efeito do Fundo de Manutenção e Desenvolvimento da Educação Básica e de Valorização dos Profissionais da Educação (Fundeb) nos resultados do Sistema de Avaliação da Educação Básica (Saeb) dos municípios por meio da estimação de um modelo de painel espacial com informações de 2007 e 2017, que contemplam os dez anos da implementação do fundo. Os resultados indicaram que o aumento de 10% no valor do Fundeb por aluno recebido pelo município elevou em, aproximadamente, um ponto a nota do Saeb. Já o aumento do valor do fundo nos municípios vizinhos contribuiu para aumentar em, aproximadamente, três pontos a nota Saeb do município. Esses resultados são uma evidência em favor da hipótese de que o Fundeb incentivou a gestão e adoção de boas práticas na educação municipal, que influenciam as decisões e o comportamento dos gestores dos municípios vizinhos para também melhorar suas práticas e resultados.
TD 2642 -Aspectos Socioeconômicos da Covid-19: evidências dos trabalhadores formais do estado do Rio de Janeiro
Authors: Medronho Roberto de A. , Travassos Guilherme H. , Farias Claudio M. de , Costa Joana , Zucoloto Graziela , Koeller Priscila , Miranda Pedro , Galliez Rafael M. , De Negri Fernanda
Published: May 2021

Este texto tem como objetivo analisar em que medida as características socioeconômicas dos indivíduos influenciam as chances de óbito pela Covid-19. Dois conjuntos de dados foram combinados para atingir esse objetivo: os registros individuais de pessoas infectadas com coronavírus no estado do Rio de Janeiro e a Relação Anual de Informações Sociais (Rais), que contém diversas informações socioeconômicas sobre trabalhadores formais do estado. A partir dessas informações, foi possível estimar modelos logísticos para avaliar o efeito de variáveis como sexo, idade, renda, raça/cor, escolaridade, ocupação e atividade econômica sobre o risco de morte pela Covid-19. Os resultados indicam que alguns grupos de trabalhadores têm mais risco de morrer dessa doença do que outros: trabalhadores empregados em estabelecimentos de saúde e segurança pública apresentam, respectivamente, um risco de morrer 2,46 e 2,25 vezes maior do que aqueles empregados em outras atividades. Os resultados também mostram que pessoas não brancas, homens e aqueles que trabalham na região metropolitana têm mais probabilidade de morrer de Covid-19. Por sua vez, quem tem ensino superior tem 44% menos chance de morrer devido à doença. É essencial considerar essas diferenças no desenho das políticas de prevenção a serem adotadas futuramente.
TD 2646- Desigualdade, Desequilíbrio e Ajuste em Sistema de Previdência por Repartição
Authors: Moreira Ajax , Ferreira Sergio Guimarães , Foguel Miguel Nathan
Published: May 2021

O SPR recebe contribuições das gerações ativas para financiar o benefício dos inativos, fazendo com que o seu equilíbrio financeiro dependa da proporção de inativos na população, proporção que irá dobrar no Brasil nos próximos 30 anos, tornando inevitável a modificação das regras para mitigar o desequilíbrio financeiro. Num sistema por repartição, o equilíbrio financeiro é obtido aumentando a contribuição ou reduzindo o benefício dos agentes, e estas alterações modificam as regras de repartição, impactando de forma diferentes os agentes nascidos no mesmo coorte e em coortes diferentes. Neste exercício, vamos avaliar o SPR em vigor no Brasil em 2019/2020, onde agentes são heterogêneos, estão inseridos em um mercado de trabalho onde existe emprego informal e os agentes nem sempre contribuem para a previdência, e existem regras que garantem um valor mínimo para o benefício, e renda mínima para o idoso pobre. O modelo utiliza cenários para a evolução futura da produtividade, da probabilidade de contribuir, da escolaridade e da demografia, para projetar o efeito de diferentes regras do SPR sobre os resultados financeiros de cada tipo de agente ao longo das gerações, e projetar o desequilíbrio financeiro do SPR em cada ano. Para evitar a necessidade de reformas paramétricas que são em geral politicamente custosas e demoradas, consideramos mecanismos de ajuste das contribuições e benefícios que garantem o equilíbrio financeiro que regulam, entre ativos e inativos e entre os tipos de agentes o ônus de anular o desequilíbrio.
Commentary - Methods to find all the edges on any of the shortest paths between two given nodes of a directed acyclic graph
Authors: Ahire Deepak , Jadhav Omkar
Published: May 2021

This article puts forth all the existing methods proposed by the various authors of the Stack Exchange community to find all the edges on any shortest path between two given nodes of a directed acyclic graph. For a directed acyclic graph with N number of nodes, an exponential number of paths are possible between any two given nodes and, thus, it is not feasible to compute every path and find the shortest ones in polynomial time to generate a set of all edges that contribute or make any of the shortest paths. The methods discussed in this article are not limited only to this specific use case, but have a much broader scope in graph theory, dynamic programming and counting problems. Generally, various other questions and answers, raised on the community portal having similar scope to those that the users specifically seek, do not receive sufficient hits and, hence, enough attention and votes for various reasons worth contemplating. Therefore, this article also aims to highlight the various scopes of the methods discussed in this article and acknowledge the efforts of the authors, moderators and contributors of the Stack Exchange community for their expertise and time to write precise answers and share their opinions and advice. Finally, it also appeals to all the other beneficiaries in the community to use their privileges responsibly and upvote the posted answers, if they helped solve their queries, as one upvote is free of cost.
Citizen science approach reveals groundwater fauna in Switzerland and a new species of Niphargus (Amphipoda, Niphargidae)
Authors: Alther Roman , Bongni Nicole , Borko Špela , Fišer Cene , Altermatt Florian
Published: May 2021

Knowledge on the diversity and distribution of subterranean organisms is still scattered, even in faunistically relatively well-researched countries such as Switzerland. This is mostly due to the restricted access to these subterranean habitats. Better knowledge on these organisms is needed, because they contribute substantially to overall biodiversity of a region, often contain unique elements of biodiversity, and can potentially be indicative of the ecological status of subterranean ecosystems that are providing important ecosystem services such as drinking water. Past research on subterranean organisms has often used highly specialised sampling techniques and expert knowledge. Here, we show that inclusion of non-professionals can be an alternative and highly promising sampling strategy. We retrieved citizen science-based samples from municipal groundwater wells across Switzerland, mainly from the Swiss Plateau. Opportunistic samples from 313 sites revealed a previously undocumented groundwater fauna including organisms from different major invertebrate groups, with a dominance of crustaceans. Here, we studied amphipods of the genus Niphargus. Among all 363 individuals sampled, we found in total eight nominal species. Two of them, namely N. fontanus and N. kieferi, are reported for Switzerland for the first time. We also found four further phylogenetic lineages that are potentially new species to science. One of them is here formally described as Niphargus arolaensissp. nov. The description is based on molecular and morphometric data. Our study proves the suitability of citizen science to document subterranean diversity, supports groundwater conservation efforts with data, and raises awareness for the relevance and biodiversity of groundwater amphipods among stakeholders.
Open Source Intelligence (OSINT), veille et intelligence économique : des croisements féconds
Authors: Deschamps Christophe
Published: May 2021

Favorisée par l’émergence du web 2.0 et le désir d’en savoir plus sur les actions des différentes organisations institutionnelles et commerciales, l’OSINT a peu à peu éveillé un intérêt grandissant, au-delà des professionnels du renseignement et de la competitive intelligence . Ses méthodes d’investigation s’avèrent proches des logiques de la veille et de l’intelligence économique. Dans la richesse protéiforme de ses applications, ces deux disciplines peuvent trouver matière à de nouveaux développements, pour répondre de façon plus efficace à des nécessités informationnelles commerciales, stratégiques ou communicationnelles.
Décryptage de trois enquêtes journalistiques réalisées grâce à l’ Open Source Intelligence (OSINT)
Authors: Rodot Emma
Published: May 2021

Les techniques de l’OSINT sont un véritable atout pour les journalistes d’investigation qui travaillent sur des terrains difficiles. Pour comprendre la démarche et saisir la valeur ajoutée de ces méthodes, voici un décryptage de trois enquêtes emblématiques réalisées par des collectifs internationaux d’enquêteurs, de journalistes et d’activistes au cours de ces deux dernières années.
Adaptive Help System Based on Learners ‘Digital Traces’ and Learning Styles
Authors: Mohssine Bentaib , Mohammed Aitdaoud , Abdelwahed Namir , Mohammed Talbi
Published: May 2021

Learning management system (LMS) such as Claroline, Ganesha, Chamilo, Moodle ..., are commonly and well used in e-education (e-learning). Most of theTechnology Enhanced Learning (TEL) focus on supporting teachers in the creation and organization of online courses. However, in general, they do not consider individual differences of each learner. In addition, they do not provide enough indicators which will help to track the learners.
In this paper, we investigate the benefits of integrating learning styles in the Web-based educational systems. Also we are interested in the use of interaction traces in order to address the lack of feedback between the learner and the teacher.
Generally, we aim to offer a tool that allows the tutor and the instructional designer to interpret learner courses, in order to provide help as needed for each individual.
Educational Recommender System based on Learner’s Annotative Activity
Authors: Mazhoud Omar , Kalboussi Anis , Kacem Ahmed Hadj
Published: May 2021

In recent years, Educational Recommender Systems (ERSs) have attracted great attention as a solution towards addressing the problem of information overload in e-learning environments and providing relevant recommendations to online learners. These systems play a key role in helping learners to find educational resources relevant and pertinent to their profiles and context. So, it is necessary to identify information that helps learner’s profile definition and in identifying requests and interests. In this context, we suggest to take advantage of the annotation activity used usually in the learning context for different purposes and which may reflect certain learner’s characteristics useful as input data for the recommendation process. Therefore, we propose an educational recommender system of web services based on learner’s annotative activity to assist him in his learning activity. This process of recommendation is founded on two preparatory phases: the phase of modelling learner’s personality profile through analysis of annotation digital traces in learning environment realized through a profile constructor module and the phase of discovery of web services which can meet the goals of annotations made by learner via the web service discovery module. The evaluation of the developed annotation based recommendation system through empirical studies realized on groups of learners based on the Student’s t-test showed significant results.
Pupils Participation in a Technology-Rich Environment: A Study of Pupil Perspective on Learners’ and Teachers’ Roles
Authors: Öberg Johanna , Nouri Jalal
Published: May 2021

It has been argued that participation as involvement as well as taking part in decision making is a fundamental part of learning. The first large arena for experiencing this for many young people is the school. This paper investigates how 16 pupils at grade eight view their own and their teacher’s role when it comes to facilitating participation. The pupils are interviewed the semester after a long researcher led participation project and the interviews are analyzed using thematic analysis. The analysis identifies four different types of participation from the pupils’ responses. These four types can be connected to passive and active participation as well as participation as involvement and participation as influence.
Motivational Elements in Computer Games for Learning Mathematics
Authors: Juric Petar , Brkic Bakaric Marija , Matetic Maja
Published: May 2021

One of the main drawbacks of delivering new teaching lessons in e-learning systems is the lack of motivation for using those systems. This paper analyses which elements of computer games for learning mathematics have a beneficial effect on intrinsic motivation and give students continuous feedback in order to improve the learning process. While the control group has access to the basic version of the educational computer game, the experimental group uses the version enriched with additional motivational elements which include enhanced graphics for indulging in the game, messages of support while playing the game, and the possibility to compare results with fellow peers in terms of trophies and medals won.
Evaluation of Changing Education System at Universities in The Pandemic Process Based on The Opinions of Faculty Members and Students
Authors: Korkmaz Selma , Gökbulut Burak , Yeniasır Mustafa , Özbent Ayşenur
Published: May 2021

Covid-19, which emerged in the Wuhan city of People’s Republic of China and affected the whole world, was first seen in Turkish Republic of Northern Cyprus and Turkey in March 2020. Due to the negative impact created by the mentioned disease, face-to-face education which was traditionally applied in Turkey and Northern Cyprus was ceded and total distance education was adopted rapidly so that education would not be hindered. Although distance education has a long history in the world, the total transformation of the system required a certain ef-fort for both students and teachers to have a command in the process. In the arti-cle, based on the opinions of faculty members and students, the education system that has completely changed in universities with the pandemic process is evaluat-ed. The distance education system, which is thought to have an important place in education after today, has been evaluated especially by pointing out the deficien-cies and making some recommendations to eliminate them. In the research, meas-urement and evaluation came to the fore as one of the most important problems in the distance education system. At this point, it is predicted that a more process-oriented measurement and evaluation process will produce healthier results.
An Evaluation Model of the Online Learning Effect Based on Fuzzy Mathematics
Authors: Tao Cuiping
Published: May 2021

This study derived an evaluation model that overcomes the various problems in the evaluation of online learning effect. Firstly, the influencing factors in the online learning process were discussed in the paper, pointing out the direction to enhance the online learning effect. Next, a multidimensional evaluation index system was established for online learning effect. Meanwhile, the evaluation of online learning effect was treated as a fuzzy evaluation problem with multiple attributes, and an improved evaluation model for online learning effect was proposed based on fuzzy mathematics theory. The proposed model can evaluate the online learning effect effectively, and enjoy a good prospect of application.
Evaluating the Service Quality of Mobile Health Versus Clinic Based Intervention in Hearing Healthcare. A Comparative Study
Authors: Ross Florian , Wohllebe Atilla
Published: May 2021

Hearing Healthcare is in midst of a paradigm shift and the use of mobile health technologies plays therefore a major role. Through the Bluetooth connectivity between the hearing aids and the smartphone with an accompanying app, the HCP can remotely access hearing aid settings during an online video session. In this study, 30 subjects were divided into a tele-audiology intervention and a clinic-based control group and followed up after an initial fitting for four weeks. At the beginning, structured interviews were used to determine the expectations on the service quality of a Hearing Aid Company, and these were compared with the actual perceived performances at the end of the study using the SERVQUAL model. Various advantages and disadvantages of both forms of intervention were identified. It could be concluded that a combination of both variants ensures the greatest possible perception of service quality.
Accelerating the Move Towards Online Learning Through Cloud Platforms in Higher Education Sectors Using Smart Devices during COVID-19
Authors: P.J. Arul Leena Rose , T Ananthi Claral Mary
Published: May 2021

Education is essential for the progress of humankind. The function of education is to teach one to think intensively and critically. Education policies are entering into a new pathway. Due to climatic and geographical conditions in many areas of the world, it is challenging to establish classes. Many students feel difficulties in leaving their motherland for further education due to the limited economy. Learning using technological components like smart devices is continually growing. Several education institutions provide services through the web using cloud-based technology to ease the students and cultivate their education. The employment of smart devices has a great perspective on teaching and learning. During COVID-19, the cloud platform helps students and faculties learn and even stay in their residential areas. This paper aims to outline: attitude and opinion of smart devices used by higher education students and their self-efficacy in participating in online classes. This teaching strategy makes a significant contribution to digital pedagogy. It includes approximately 360 respondents. The results revealed that students' perceptions of device usage, connectivity, and time duration had a statistically significant effect on cloud-based online learning, and self-efficacy depicts a positive impact on their online classes. Thus smart devices play a vital role in extending learning out of the classroom anywhere, anytime.
Determining Appropriate Social Media Sites for Knowledge Sharing
Authors: Gyamfi Albert
Published: May 2021

The study aims at developing a fully developed and operational cloud-based published website for predicting appropriate social media for sharing knowledge during an outbreak. The media richness theory (MRT) is used in establishing the relationship between the richness of a social media platform, which is based on four criteria—ability to provide feedback, multiple cues, language variety, and personal focus—and the level of equivocality and uncertainty in the knowledge sharing task. A survey is used to gather data on the use of four social network sites (SNSs) (Facebook, Twitter, YouTube, and Instagram) that were mostly used for sharing knowledge during the COVID-19 pandemic. Data science techniques are used to analyze the data and develop a system for selecting appropriate social media for sharing knowledge.
Software Development Knowledge Management System Using Web Portal
Authors: Pal Kamalendu , Williams Idongesit
Published: May 2021

Software development is a knowledge-intensive practice. Software development teams rely on human resources and systematic approaches to share knowledge on system design. This collaborative knowledge sharing and preserving mechanism is known as “knowledge management” in software industries. In the software development process, coordination of system design functionalities requires knowledge-sharing infrastructure within the team members. Semantic web service computing (SWSC) provides opportunities and value-added service capabilities that global software development team requires to exchange information. This chapter describes the features of an ontology-based web portal framework, called CKIA (Collaborative Knowledge Integration Architecture), for integrating distributed knowledge in a global software development project. The CKIA framework uses a hybrid knowledge-based system consisting of Structural Case-Based Reasoning (S-CBR), Rule-Based Reasoning(RBR), and an ontology-based concept similarity assessment mechanism. A business scenario is used to present some functionalities of the framework.
Testing of Carbon Nanotubes and their Influence on the Physical and Mechanical Characteristics of Polyester Resin
Authors: Shuklin S.G. , Velm I.M.
Published: May 2021

Carbon nanotubes have been studied by scanning electron microscopy. Measurement modes - accelerating voltage 10 kV, current in microscopy mode 10-9 A. The sample was applied to a metal mesh. Spectroscopic data indicate that this sample consists of carbon (peak at 280 eV). There are no other intense peaks in the spectrum; no impurities were detected by this method. Determination of physical and mechanical characteristics was carried out on a testing machine model N5K-S.
Direct Synthesis of Titanium Nanoparticles by Induction Flow Levitation Technique
Authors: Markov A.N. , Vorotyntsev A.V. , Andronova A.A.
Published: May 2021

The paper considers the technology of obtaining metal nanoparticles by the method of induction levitation. A bulk metal sample of titanium with a purity of 99.9% and a mass of 0.4 g, which was heated and held in a state of flux levitation by a high-frequency electromagnetic field, was used as the basic raw material for nanoparticles. The obtained nanoparticles were examined using Х-ray diffraction analysis to determine the purity of the product. The analysis showed that it is high. Particle size distribution was investigated using dynamic light scattering, where the average particle diameter is 55 and 47 nm, obtained in Ar and He, respectively. The morphology was studied using scanning electron microscopy, according to which the average diameter of the particles synthesized with He and Ar is 45 and 57 nm, respectively.
Polychelates Based on Magnesium, Aluminum, Iron, Zirconium, and Vanadyl Acetylacetonates - Synthesis, Structure and Properties
Authors: Shapkin Nikolai P. , Tokar E.A. , Gardionov S.V. , Korochentsev V.V. , Kuryavyi V.G. , Papynov E.K. , Khalʻchenko I.G.
Published: May 2021

The formation of polymeric acetylacetonates of magnesium, aluminum, iron, zirconium, and vanadyl under conditions of mechanochemical activation with subsequent condensation in boiling toluene has been investigated. The obtained compounds have been studied by the methods of gel chromatography, X-ray diffractometry, and positron annihilation and IR spectroscopy. Aluminum chelates have been studied by means of NMR spectroscopy. It has been demonstrated that the mechanochemical activation with subsequent boiling in toluene results in the formation of polymeric chelates, mostly those of iron, zirconium and, to a smaller degree, chelates of aluminum, magnesium, and vanadyl. The molecular weight of soluble high-molecular fractions is in the range 3000–5000 Da. The layered polymer structure has been revealed. Cross-section areas of polymer chains and volumes of coherent scattering regions have been calculated from the diffractometry data. The morphology of polymers consisting of spherical particles of sizes in the range 100–700 nm has been investigated. Based on the data of positron annihilation spectroscopy (PAS), density, and nitrogen low-temperature adsorption, the dependence of the chelate stability on the specific polarizing potential has been determined. A fractal structure of solid-state polychelates has been revealed.
Special Features of Formation of the High Damping State in Bimetallic Structural Materials Obtained by Explosion Welding
Authors: Chudakov I.B. , Fedotova N.L. , Saikov I.V.
Published: May 2021

Special features of the high-damping state formation in bimetallic materials produced by explosion welding have been studied. High-damping Mn-Cu alloy was used for the damping base of the bimetallic composite and high–strength steel (grade: 30HGSA) was used to form the coating layer. The effect of planar tensile stresses (observed in the damping component of the bimetal and caused by valuable difference between coefficients of thermal expansion of components of the bimetal) is discussed. Damping properties of bimetallic materials were found to be comparable with damping characteristics of monolithic high damping alloys. High-strength steel provides high-strength characteristics of the surface layer of the bimetal, where the strength level reaches 1100MPa and the hardness is equal to 50 HRC. Obtained combination of high damping and high strength in developed bimetallic materials provides real chance for practical application of these materials in industry.
Channel Angular Pressing of the Annular Metal Billet
Authors: Ivanov A.M. , Vaschenko S.S.
Published: May 2021

The article presents the developed method of channel angular pressing of the annular billets and gives the examples of hardening annular aluminum billet by channel angular pressing. The channel angular pressing is shown to result in aluminum hardening by 1.4 to 1.5 times. This increases the diameter of the annular billet.
Heat Treatment of the Surface of the ChS57 Alloy with Powerful Nanosecond Ultraviolet Laser Pulses
Authors: Khomich Yu.V. , Mikolutskiy S.I. , Rogalin V.E. , Kaplunov I.A. , Ivanova A.I.
Published: May 2021

The threshold of optical breakdown of the nickel alloy ChS57 (Inconel) was measured at a wavelength of 0.355 μm with a laser pulse duration of 10 ns. Heat treatment of ChS57 above pulse energy density threshold (1 - 2.5 J/cm2) occurred mainly in the ablative mode with almost no melting. The elemental composition of the surface layer did not change at an irradiation in a fixed spot. When a laser beam moves along the surface of the sample at a speed of 1 mm / s and at pulse energy density of about 0.02 J/cm2, oxygen was detected in the elemental composition (3 – 4 wt. %). However, the proportions of the elemental composition of the alloy remained virtually unchanged. Heat treatment under threshold at pulse energy density ≥ 0.25 J/cm2 revealed a rise of the surface layer with traces of high-temperature plastic deformation in the form of slippage on grain boundaries and crystallographic slip.
The Effect of Surface Conditions on Corrosion Resistance of a Cobalt-Chromium Alloy
Authors: Spektor V.S. , Sarychev S.M. , Orlov A.A.
Published: May 2021

The article discusses the effect of the surface conditions on the corrosion resistance of alloys based on cobalt, titanium and stainless steel, which are currently used for the manufacture of components for implantable medical devices. It is shown that an increase in surface roughness has practically no effect on the corrosion resistance of alloys based on cobalt and titanium.
On the Issue of Laser Selective Removal of Paint Coating from a Sample of Metal Plating of Aircraft Gliders
Authors: Polonik Marina V. , Mantsybora Alexandr A.
Published: May 2021

In this paper the temperature fields in the zone of processing of paint coatings by laser radiation of a sample of the metal skin of aircraft gliders with selective (layer-by-layer) removal are researched. The performed theoretical studies and numerical calculations made it possible to carry out practical tests and develop conditions under which the physical effect of laser energy causes minimal damage to the alloys and composites of the sample, as well as to assess the effect of the laser on the properties of materials used in the aerospace industry. The obtained results are reflected in the technology of laser selective removal of paint coatings from metal and composite skin of aircraft gliders.
Development of Titanium Implants with a Rough Calcium Phosphate Surface to Control the Morphofunctional State of Stem Cells
Authors: Yurova K.A. , Khlusov Igor A. , Litvinova L.S.
Published: May 2021

Experimental titanium implants with a rough calcium phosphate (CР) coating with bio-inspired properties have been developed. The role of roughness (in the range Ra = 2.4 - 4.6 μm) of the surface CP simulating the physicochemical features of the mineral substance of regenerating bone tissue to change the growth and morphofunctional activity of mesenchymal stem cells (MSCs) was evaluated. Titanium substrates with a microrelief CP coating bearing artificial niches for stem cells was shown in vitro to have an epigenomic effect on MSCs, that contributes to their differentiation and maturation in bone cells. The results show the promise of developing and introducing a new class of medical devices with bio-inspired surfaces into clinical practice for traumatology and orthopedics.
Thermal Changes in the Mass, Size and Density of Steel Fiber Concrete after Calefaction
Authors: Zaitsev D.V.
Published: May 2021

This report outlines the results of an experimental study conducted on the effects high temperatures have on changes in linear sizes, mass, and density of steel fiber concrete containing fiber with varying durability, types, diameter, and percentages by volume. After being exposed to heat, the steel fiber concrete reduces in linear size, as well as decreasing in mass and density. Changes are seen as a result of rising temperatures between 20-1100 °С The impact on the change in mass, size and density of the quantity and type of fiber is not unambiguous, it does not fully correspond to the theoretical concepts considered in the work and require additional research.
Investigation of the Rate of Vacuum-Conductive Drying of Wood-Particle Panels Based on Polyvinyl Alcohol
Authors: Safin R.R. , Lyamina L.V. , Safina A.V. , Mukhametzyanov Sh.R.
Published: May 2021

Wood composites are promising construction and finishing materials that offer the best properties of both wood and polymers. With the industry's need to use low-toxic adhesives in view, one of the ways to ensure the environmental friendliness of composites is the use of polyvinyl alcohol as a binder. In this respect, in order to streamline production, both in terms of reducing energy consumption and improving the quality of the final product, it is vital to choose the drying rate when pressing panels. The paper presents the results of a study of the process of vacuum-conductive drying of eco-friendly polyvinyl alcohol (PVA)-based wood-particle material. It was found that the composite samples with a PVA content of 40% in terms of physical and mechanical parameters (ultimate bending strength and ultimate tensile strength perpendicular to the panel face) fully comply with the established standards. The study provided the values of drying rate depending on 5 factors. The multi-factor regression analysis method was used to derive equations that determine the drying rate of polyvinyl alcohol-based wood-particle panels for two humidity intervals (above and below the cell walls humidification limit), taking into account the properties of different classes of bodies that make up the composite.
Polymer-Bitumen Binders Compositions Selection by Using the Experimental Planning Method
Authors: Galdina V.D. , Galdin N.S.
Published: May 2021

The paper presents the studies on the compositions selection and properties of polymer-bitumen binders obtained using the viscous petroleum bitumen, styrene-butadiene-styrene polymer and plasticizer according to the experimental planning method. Regression equations of the polymer-bitumen binders processing and performance properties, which make it possible to optimize the compositions and predict their properties taking into account the operating conditions, were obtained. Polymer-bitumen binders in comparison with the properties of viscous road bitumen have the increased indicators of heat resistance, crack toughness, ductility and elasticity. To obtain the adequate mathematical model, the experimental data were processed, compositions were optimized and dependence diagrams were constructed by using the Maple software package. The software for a personal computer including the algorithm and program for selecting the polymer-bitumen binders has been developed. When using the software it is possible to automate the calculation of the polymer-bitumen binders compositions with a given set of technical properties.