bluuebunny/crossref_metadata_2025 huggingface dataset:
The Attitude of Students and the Mediating Effect of Acceptance, Interactivity and LMS on Integration of Technology
Authors: Gyau Yaw Odame , Gyan Ernest Kwabena , Semarco Stanley
Published: July 2023

Although the phenomenon of technology is gradually being integrated into tertiary education in Ghana, the perceptions of students to adopt and adapt to learning technologies for smooth integration of technology into academic programmes in public universities is an issue of concern. Using the Constructivist and Positivist paradigm, this study adopted the quantitative approach and the purposive and quota sampling technique to solicit data from 1704 level 400 students in six (6) accredited public universities. Adopting the regression analyses approach with ten hypotheses tested the results were analyzed with PLS-SEM. The study found that the attitudes of students significantly impact the integration of technology. Indirectly, Students’ Acceptance and Adjustment (AA) to use technology and Learning Management System (LMS) usage significantly mediates the relationship between the Attitude of Students (AS) and the Integration of technology (IG). Furthermore, students’ acceptance and adjustment to adopt technology and the use of the LMS, are key predictors of the integration of technology, but Interactivity is a weak predictor of the integration of technology into academic programmes in the topmost public universities in Ghana.

Keywords: Attitude, Acceptance and Adjustment, Interactivity, Learning Management Systems, Integration of Technology.
Photometry of Type II Supernova SN 2023ixf with a Worldwide Citizen Science Network
Authors: Sgro Lauren A. , Esposito Thomas M. , Blaclard Guillaume , Gomez Sebastian , Marchis Franck , Filippenko Alexei V. , Peluso Daniel O’Conner , Lawrence Stephen S. , Verveen Aad , Wagner Andreas , Nardi Anouchka , Wiart Barbara , Mirwald Benjamin , Christensen Bill , Eramia Bob , Parker Bruce , Guillet Bruno , Kim Byungki , Logan Chelsey A. , Kyba Christopher C. M. , Toulmin Christopher , Vantaggiato Claudio G. , Adhis Dana , Gary Dave , Goodey Dave , Dickinson David , Koster David , Martin Davy , Bonilla Eliud , Chung Enner , Miny Eric , Mortecrette Fabrice , Saibi Fadi , Gagnon Francois O. , Simard Franois , Vacon Gary , Simard Georges , Dreise Gerrit , Funakoshi Hiromi , Vacon Janet , Yaniz James , Le Tarnec Jean-Charles , Laugier Jean-Marie , Siders Jennifer L. W. , Sweitzer Jim , Dvoracek Jiri , Archer John , Deitz John , Bradley John K. , Fukui Keiichi , Sibbernsen Kendra , Borrot Kevin , Cross Kevin , Heider Kevin , Yamaguchi Koichi , Hirsch Lea A. , Leroux Liouba , Billiani Mario , Lorber Markus , Smallen Martin J. , Shimizu Masao , Nishimura Masayoshi , Ryno Matthew , Cunningham Michael , Gagnon Michael , Primm Michael , Rushton Michael , Sibbernsen Michael , Mitchell Mike , Yoblonsky Neil , Leroux Niniane , Clerget Olivier , Stojanović Ozren , Unique Patrice , Huth Patrick , Ang Raymund John , Santoni Regis , Foster Robert , Poggiali Roberto , Xu Ruyi , Kukita Ryuichi , Šćepanović Sanja , Saibi Sophie , Will Stefan , Latour Stephan , Haythornthwaite Stephen , Cadieux Sylvain , Müller Thoralf , Chung Tze Yang , Watanabe Yoshiya , Arnaud Yvan
Published: July 2023

We present highly sampled photometry of the supernova (SN) 2023ixf, a Type II SN in M101, beginning 2 days before its first known detection. To gather these data, we enlisted the global Unistellar Network of citizen scientists. These 252 observations from 115 telescopes show the SN’s rising brightness associated with shock emergence followed by gradual decay. We measure a peak M

V
 = − 18.18 ± 0.09 mag at 2023 May 25 21:37 UTC in agreement with previously published analyses.
Should we estimate plant cover in percent or on ordinal scales?
Authors: Dengler Jürgen , Dembicz Iwona
Published: July 2023

Question: We explored the error resulting from different methods for recording the cover of plants in vegetation plots, specifically the direct estimation of percent cover vs. the use of ordinal cover scales (7-step Braun-Blanquet and 5-step Hult-Sernander-Du Rietz). Methods: We simulated 121 plant species of different cover, sampled with 13 different levels of estimation precision. Estimation precision was either based on a constant coefficient of variation (0.1–1.0) across all cover values or on empirical data from Hatton et al. (1986, Journal of Range Management 39: 91–92) (× 0.5, × 1.0, × 1.5). Each sampling was repeated 10 times. Subsequently, we determined the mean relative and absolute errors that occurred in the data used for ensuing numerical analyses. Results: Except for few cases with unrealistic settings (very high estimation error and ignorance of species with lower cover values), direct estimation in percent yielded better results than the use of ordinal scales. Based on the empirical values of estimation accuracy, the use of ordinal scales inflated the mean absolute and relative errors nearly 2-fold in case of the 7-step Braun-Blanquet scale and about 1.5-fold in case of the Hult-Sernander-Du Rietz scale if only considering cover values above 1%. Conclusions: From our personal experience, the careful application of an ordinal scale is not faster than the direct estimation of percent cover. For this reason, we see no plausible argument supporting the use of ordinal cover scales when essentially all subsequent analyses are numeric.

Abbreviations: Br.-Bl. = 7-step variant of the Braun-Blanquet scale and its numerical replacement as in Table 2; CV = coefficient of variation; H.-S. = Hult-Sernander-Du Rietz scale and its numerical replacement as shown in Table 1.
Common but ignored: a new species of Cyrtodactylus (Chordata, Reptilia, Squamata, Gekkonidae) from lowland Sumatra Barat, Indonesia
Authors: Nugraha Fitra Arya Dwi , Ahda Yuni , Tjong Djong Hon , Kurniawan Nia , Riyanto Awal , Fauzi Muhammad Alif , Lin Si-Min
Published: July 2023

The lowland region of Sumatra Barat has received little attention in previous biodiversity studies. Past studies have mainly focused on highland habitat and conservation areas. However, many populations of Cyrtodactylus in the lowland habitats of Sumatra Barat were not correctly identified. A phylogenetic tree based on the NADH dehydrogenase subunit 2 (ND2) gene showed that the lowland Sumatran population is the sister group of the Malaysian lowland species, C. semenanjungensis, together nesting within the agamensis group. The genetic divergence within the Sumatra Barat population is 0–4.2% and 18.3–20% to C. semenanjungensis. Further examination of morphological characters revealed that they differed from the sister clade and other Sumatran Cyrtodactylus members by a unique combination of characters such as absence of tubercle on brachium, presence of tubercle on ventrolateral fold, 32–41 paravertebral tubercles, 38–46 ventral scales, enlarged femoral scales, presence of precloacofemoral pores and 22–23 subdigital lamellae under fourth toe. Based on the morphological and molecular evidence, the lowland Sumatran population is herein described as a new species, increasing the number of species in Sumatra to seven. More comprehensive and intensive sampling efforts would most likely yield further discoveries in the group of Sumatran Cyrtodactylus in the near future.
Putting the Mouth Into the Head-to-Toe Assessment: Nursing Oral Health Assessment Training With an Oral Health Therapist
Authors: Oda Keiko , Majeed Sarah , Parsons John , Boyd Michal , Smith Moira
Published: July 2023

Background:

Oral care is one of the most neglected nursing practices, lacking oral care protocols, efficient training, and awareness of the benefits for clients. In particular, there is a gap in research for nursing oral health assessment training for nursing curricula.

Method:

This study explored the effects of interprofessional collaboration (IPC) training between nurses and oral health therapists (OHT) using newly developed oral health assessment tools with an aim of reducing barriers for nursing oral health assessment. The self-efficacy and confidence of nursing students in oral health assessment were evaluated using pre- and posttraining surveys, and a focus group.

Results:

Nursing students' confidence in incorporating oral health assessment into head-to-toe assessment improved after training.

Conclusion:

Nursing oral health assessment training with IPC, onsite OHT support, and oral health assessment tools improved the confidence and attitudes of nursing students in oral health assessment and care provision.

[
J Nurs Educ
. 2023;62(7):399–402.]
The spread of debt risk from real estate companies to banks: Evidence from China
Authors: Zhong Yonghong , Zhong Junhao
Published: July 2023

The recent real estate debt crisis in China has dealt a huge blow to the banking sector. To address this challenge, we construct a dynamic game model that considers the interaction of the government, banks and real estate companies. The model is used to analyze the default behavior of real estate companies and loan losses for banks when facing information asymmetry. In addition, we empirically demonstrate the contagion effect of debt risk of real estate companies to banks, using a sample of 119 listed real estate companies and 42 listed banks in China from 2001 to 2020. The results show the following. (1) The debt risk associated with non-state-owned real estate companies is more likely to be contagious to banks compared to state-owned real estate companies. (2) The contagion effect of debt risk of real estate companies to banks is more significant among small and medium-sized banks. (3) The debt risk of non-state-owned real estate companies is most contagious for rural banks, followed by urban banks. Further tests show that the rising debt risk of non-state-owned real estate companies significantly increases the asset risk of small and medium-sized banks. This effect is reinforced through the liquidity channel. This implies that controlling the contagion of debt risk of non-state-owned real estate companies to small and medium-sized banks is an effective way to prevent the occurrence of banking crises.
Analysis of the Incidence of Macrosomia in Japan by Parental Nationalities at 5-year Intervals From 1995 to 2020
Authors: Okui Tasuku
Published: July 2023

Objectives: We investigated trends in the incidence rate of macrosomia and its association with parental nationalities using Vital Statistics data in Japan.Methods: We used singleton birth data every 5 years from 1995 to 2020. The incidence rate of macrosomia was calculated according to specific attributes (maternal age, infant’s sex, parental nationalities, parity, and household occupation) over time (years). In addition, a log-binomial model was used to investigate the relationship between the incidence of macrosomia and the attributes. This study compared Korea, China, the Philippines, Brazil, and other countries with Japan in terms of parental nationalities. “Other countries” indicates countries except for Japan, Korea, China, the Philippines, and Brazil.Results: The study included 6 180 787 births. The rate of macrosomia in Japan decreased from 1.43% in 1995 to 0.88% in 2020, and the decrease was observed across all parental nationalities. The rates for Japanese parents were the lowest values among parental nationalities during the timespan investigated. Multivariate regression analysis showed that mothers from Korea, China, the Philippines, Brazil, and other countries had a significantly higher risk of macrosomia than those from Japan (risk ratio, 1.91, 2.82, 1.59, 1.74, and 1.64, respectively). Furthermore, fathers from China, the Philippines, Brazil, and other countries had a significantly higher risk of macrosomia than those from Japan (risk ratio, 1.66, 1.38, 1.88, and 3.02, respectively).Conclusions: The rate of macrosomia decreased from 1995 to 2020 in Japan for parents of all nationalities, and the risk of macrosomia incidence was associated with parental nationality.
The Use of Augmented Reality through Assemblr Edu to Inspire Writing in an Ecuadorian EFL Distance Program
Authors: Carrión-Robles Fernando , Espinoza-Celi Verónica , Vargas-Saritama Alba
Published: July 2023

This study analyzed the effectiveness of using augmented reality (AR) through the Assemblr Edu platform to improve English as a foreign language (EFL) writing skills in distance education. The participants included 40 freshmen university students who speak English at a basic level. This case study was approached through the mixed method. The data collection instruments encompassed a pre-test, a post-test, written tasks assessed through a rubric, and a survey. Findings evidenced that Assemblr Edu enhanced participants’ writing-skill development in terms of organization and structure of paragraphs as well as grammar, vocabulary, and punctuation. This was thanks to the augmented reality elements in 3D, which allowed the designing of teaching material incorporating interactive activities, videos, images, and multimedia elements.
National Wealth
Authors: Manta Otilia
Published: July 2023

One of the crucial factors that contribute to establishing well-being at the level of the world economies, as recognized by institutions such as the World Bank, is the management and distribution of the national wealth at both the national and global levels. Throughout history, each state has relied on the resources it possess and protects. In today’s world, it is more important than ever to have knowledge of and inventory these resources, not only to support one’s own economic sectors, but also to actively contribute to economies in need. The definition of national wealth is particularly significant in the context of ongoing discussions about limited resources at the global level. Moreover, it is crucial to highlight the defining elements of economic development at both the national and global levels. Such developments cannot be achieved without considering the unique characteristics of each state, including their strengths and weaknesses, particularly in terms of their resources. This paper aims to explore conceptual aspects and reference indicators for measuring national wealth. Doing so not only serves as an indicator of the sustainability of our economy but also provides a reference indicator for states worldwide.
Forecasting and Directions Regarding Sustainable Public Procurement
Authors: Rusu Elena , Manta Otilia
Published: July 2023

In the present research, the author presents the public procurement system as a significant lever for governments to accelerate the transition to more sustainable modes of consumption and production and, more generally, to contribute to the broader goal of sustainable development. Sustainable Public Procurement (SPP) is a process through which public entities procure goods, services, works, and utilities in optimal conditions, considering factors such as price and quality, in order to generate benefits entities while minimizing negative impacts on the environment. Consequently, this paper proposes some methodological issues that could contribute to the establishment of a SPP system, based on the model implemented and applied in EU countries. Additionally, this paper focuses on forecasting and presenting the current situations of public procurement as the basic element.
First Light: Encountering Edward Said and the Late-Style Jewish Prophetic in the New Diaspora
Authors: Ellis Marc
Published: July 2023

Encountering Edward Said on Yom Kippur: Reflections on the Late-Style Jewish Prophetic is a fascinating and controversial collection of journals and meditations on the plight and possibility of the prophetic witness in the modern world. In these pages, the Jewish theologian, Marc H. Ellis, explores the prophetic through his encounters with the late Palestinian intellectual, Edward Said, as a way of thinking through the stakes of contemporary Jewish history. His unexpected encounter with Said on Yom Kippur provides a fascinating window to explore the dangers and possibilities of present-day Jewish life and its future. Ellis applies Said’s idea of late-style to the Jewish prophetic – what Ellis names the Late-Style Jewish Prophetic – to mean the reappearance and coming home of the Jewish prophetic as it undergoes its own deconstruction and re-emergence. At turns deeply personal and creatively theoretical, Ellis doesn’t shy away from the forbidden terrains of self questioning and progressive posturing, even with people and movements he identifies with. The result is a sensitive and provocative exploration filled with questions and responses rather than definitive answers.
La prensa española y la epidemia de fiebre amarilla de Barcelona de 1821
Authors: Dufour Gérard
Published: July 2023

En 1821, toda Francia siguió con apasionamiento la evolución de la epidemia de fiebre amarilla en Barcelona que fue el principal centro de interés de la prensa, que, sorprendentemente, utilizó poco como fuente de información lo publicado en los periódicos españoles, al contrario de lo que se solía hacer en una época en la que no existían agencias de prensa. ¿Por qué motivo? Analizando la manera con la que los diarios dieron cuenta de la crisis sanitaria en la capital catalana, este artículo intentar dilucidar este enigma. Aunque todo el país mostró la mayor compasión y solidaridad con los infortunados barceloneses, la atención mediática fue muy distinta según se manifestó en los diarios de la capital catalana, los madrileños de alcance nacional o esencialmente local, y los de las demás provincias. Con toda evidencia, fuera de la propia Cataluña, la fiebre amarilla no fue «la cuestión palpitante»: la preocupación por la situación política lo llevó sobre la suscitada por las consecuencias dramáticas de la epidemia.
La prensa y las gramáticas del jesuita expulso Matías de Rueda, pertinaz afrancesado
Authors: Astorgano Abajo Antonio
Published: July 2023

Le jésuite espagnol expulsé Matías de Rueda y León (1741-vers 1820) se distingue par sa francisation persistante, dans son sens le plus large d'admiration pour la culture et la langue françaises. Il fut l'un des premiers sécularisés de Corse en septembre 1767 à s’installer à Bayonne et dans d'autres villes du sud de la France, comme Nîmes et Avignon, se consacrant à l'enseignement et à l'étude de la grammaire française et espagnole pour le reste de sa vie. En France, il composa trois œuvres grammaticales : Grammaire espagnole à l'usage des François, publiée à Nîmes (1797) ; Grammaire française à l'usage de la nation espagnole, à Avignon (1801) ; et la troisième, Grammaire complète et raisonnée de la langue espagnole pour les usages de la nation, restée inédite et perdue, malgré son intérêt depuis son retour en Espagne au début de 1809 jusqu'à la défaite des Français (1813). On ne sait pas exactement combien de temps Rueda est resté en France, car cela varie dans les annonces des publications de ses Grammaires dans la presse madrilène (Gaceta de Madrid et Diario de Madrid), où il a tenu quelques débats, comme avec l'abbé asturien Juan Manuel Alea dans les premiers mois de 1811.
Infográficos sobre la COVID-19. Análisis de la evolución temática en El País Digital (2020-2021)
Authors: Muñoz-Fernández Natalia , Lucas-Barcia Elisa
Published: July 2023

El carácter didáctico de los infográficos facilita la comprensión de datos aparentemente complejos, por lo que la infografía se ha constituido como una herramienta esencial en los últimos dos años en tanto que ha ejercido como la intermediaria más adecuada entre autoridades y ciudadanos gracias a la prensa. Mediante un análisis de contenido, de carácter descriptivo y exploratorio, y de corte cuantitativo, se analizan las infografías publicadas por El País en su edición digital durante los dos primeros años de crisis sanitaria (n=599). Los resultados revelan que los infográficos dan respuesta a multitud de aspectos relacionados con la pandemia de coronavirus y que más de la mitad de los artículos analizados se agrupan en torno a las tres mismas temáticas, siendo las más habitual el seguimiento de contagios y fallecidos (n=173). Por ello, este trabajo aporta una visión actualizada desde una perspectiva temporal más amplia que sus precedentes, lo que permite identificar y profundizar en las variaciones ocasionadas en las diferentes olas y supone, en definitiva, un avance en la investigación sobre los infográficos publicados en prensa que están relacionados con la salud pública.
Marie-Thérèse Eyquem ou l’émancipation sous contrôle des pratiques corporelles féminines (1942-1961)
Authors: Saint-Martin Jean , Cardin Lise , Walther Lisa
Published: July 2023

Entre 1942, année où elle est nommée chargée de mission de l’éducation physique et des sports féminins auprès et 1961 où elle devient Inspectrice de la Jeunesse et des Sports, Marie-Thérèse Eyquem multiplie les initiatives pour sensibiliser les jeunes françaises aux buts hygiéniques et esthétiques des exercices physiques. L’objet de cet article vise à interroger cet engagement continu durant deux décennies et ses effets sur les transformations de l’éducation physique féminine. Il s’agira alors de mesurer à la fois l’importance des sources d’inspiration de cette actrice et l’évolution de sa trajectoire intellectuelle pour tenter d’expliquer en quoi l’émancipation sous contrôle des femmes qu’elle ne cesse de promouvoir s’appuie pour partie sur une liberté surveillée du corps féminin.
Amniotic Fluid Embolism: A Case Report
Authors: Munasinghe K. R. , Vidanapathirana M.
Published: July 2023

Amniotic fluid embolism (AFE) is known to cause a serious reaction triggered by the entry of amniotic fluid or other debris into the maternal circulation.[1] It has been recently suggested that amniotic fluid embolism is an anaphylactic syndrome of pregnancy involving the complement system, causing vasospasm, oedema, and early onset disseminated intravascular coagulation (DIC), which is one of the causes of sudden death in obstetrics.[1] Suspicion of (AFE) should be considered in any antepartum or postpartum collapse if no obvious cause is known. We present a case of a 35-year-old mother at 35 weeks of gestation who collapsed during her early labour with no clue about the diagnosis and died soon after the admission despite vigorous resuscitation.
Magnetic Resonance Imaging Assessment of Articular Disc Position in Temporomandibular Disorder Subjects with Various Bite Registrations
Authors: Yezdani Arif , Tajir Faisal , Mohammed Jalal S. M. , Kannan M. S. , Padmavathy Kesavaram
Published: July 2023

Objective:

This study aimed to evaluate the validity and reliability of three bite registrations on articular disc position in temporomandibular disorder patients using magnetic resonance imaging (MRI).

Materials and Methods:

Fifteen clinically symptomatic and orthodontically untreated temporomandibular disorder patients within the age range of 17–40 years (mean age: 28.5 years) were examined. Each patient was subjected to three bite registrations, namely maximum intercuspation, initial contact bite and Roth power centric bite, and evaluated with MRI.

Results:

On the right side, the mean vertical and horizontal measurement values of the point in the most posterior aspect of the posterior band of the articular disc in relation to horizontal reference line (HRL) and vertical reference line (VRL) in the sagittal view in the Roth power centric bite were lesser (2.720 ± 1.239 mm and 2.380 ± 1.185 mm, respectively), in comparison with the other two bites, and on the left side too, it was lesser in the Roth power centric bite (2.293 ± 0.979 mm and 2.360 ± 1.078 mm, respectively), when compared to the other two bites. Statistical analysis also showed the significance of Roth power centric bite over the other two bites.

Conclusions:

Favourable articular disc positional changes were observed in the Roth power centric bite followed by the initial contact bite and that maximum disc recapture was observed in most patients with the Roth power centric bite rather than in initial contact bite and maximum intercuspation positions. The Roth power centric bite could be assumed to be the ideal method for articulation and fabrication of gnathological splints for treating patients with temporomandibular disorders.
Quality Assurance Sampling and Testing Corrosion- and Heat-Resistant Steel and Alloy Forgings
Authors:   AMS F Corrosion and Heat Resistant Alloys Committee
Published: July 2023

This specification covers quality assurance sampling and testing procedures used to determine conformance to applicable material specifications of corrosion- and heat-resistant steel and alloy forgings.
Ehrlichiosis in Southern Ohio: Two case reports and a review of the literature
Authors: Gotfried Robert
Published: July 2023

Tick-borne disease is becoming more commonplace as humans encroach on endemic regions with high tick preponderance. The incidence of ehrlichiosis is rising in conjunction with the increasing prevalence of its associated vector, Amblyomma americanum. In Ohio, populations of A. americanum have been expanding their range and growing in abundance and distribution. Southern Ohio in particular, has been identified as having a expanding population of E. chaffeensis infected ticks. The initial symptoms of ehrlichiosis are frequently vague and ill-defined. Often patients are not aware of having sustained a tick bite. Successful diagnosis and treatment of ehrlichiosis requires an index of suspicion, an awareness of local epidemiology, and prompt recognition of characteristic laboratory abnormalities consistent with E. chaffeensis infection. Patients in regions where these infections are known to exist, who present during tick season with fever, leukopenia and/or thrombocytopenia, and increased serum transaminase levels, should have ehrlichiosis included in the differential diagnosis. Left untreated, patients with ehrlichiosis can develop severe complications, including death. Doxycyline is the drug of choice for ehrlichiosis and should be initiated in symptomatic patients with a history of tick bite; it should not be withheld while awaiting lab results.
Novel Gene Abnormality in Epilepsy with Myoclonic-Atonic Seizures (Doose Syndrome)
Authors: Magsi Rayan , Ryan Casey , Sheikh Ajaz , Noor Mariam , Mahfooz Naeem
Published: July 2023

Introduction:

Doose Syndrome is a myoclonic-atonic seizure disorder most prominent in the pediatric population. Several common genetic mutations have been identified. However, SUOX gene mutations have not yet been correlated with Doose Syndrome.

Case Report:

At the age of 5, the patient presented with absence seizures followed by the development of generalized tonic-clonic and myoclonic-atonic seizures. She was diagnosed with Doose Syndrome based on her clinical presentation and EEG findings. An MRI found an incidental left choroidal fissure cyst. Multiple medical interventions failed to control seizures. To date, the patient has shown partial response to clobazam (40 mg/day), phenobarbital (97.5 mg/day), and a ketogenic diet.

Conclusion:

SUOX gene defects have been associated with isolated sulfite oxidase deficiency. However, our patient did not have the typical presentation, progression, and symptomology of this disorder. Instead, several possible sources for the seizures were identified; the mutation itself, focal seizures originating from the brain lesion which then generalizes mimicking Doose Syndrome, or a synergistic role between the cyst and genetic mutation.
Infinite Numbers of Infinite Classes L-Borderenergetic Graphs
Authors:   College of Computer Science and Technology, Hengyang Normal University, China, Li Qiuping , Tang Liangwen ,   College of Computer Science and Technology, Hengyang Normal University, China
Published: July 2023

The graph G of order n is an L-borderenergetic graph which means it has the same Laplacian energy as the complete graph Kn. In this paper, we find that the combination of complete bipartite graphs and stars can construct infinite numbers of infinite classes L-borderenergetic graphs. We give two infinite numbers of infinite classes L-borderenergetic graphs and two infinite classes Lborderenergetic graphs under the operators union, join and their mixed. This research could provide experience for further study the structural characteristics of L-borderenergetic graphs.
Relationship between Ordinary, Laplacian, Randić, Incidence, and Sombor Energies of Trees
Authors:   Department of Mathematics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand, Tabassum Hafsah , Kaemawichanurat Pawaton ,   Department of Mathematics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand, Adeela A. ,   University of Management and Technology Lahore, Pakistan, Wiroonsri Nathakhun ,   Department of Mathematics, Faculty of Science, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
Published: July 2023

The sum of the absolute values of the eigenvalues of the graph’s adjacency matrix is known as its ordinary energy. Based on the eigenvalues of a range of other graph matrices, several other equivalent energies are being considered. In this work, we considered ordinary energy, Laplacian, Randi´c, incidence, and Sombor energy to analyze their relationship using polynomial regression. The performance of each model is exceptional with cross-validation RMSE mostly below 1.
EMPTY VOTING AND THE PRINCIPLE OF NON-SPLITTING OF SHARE - THE EUROPEAN LAW LEGISLATIVE FRAMEWORK (AND EXAMPLES OF ITS IMPLEMENTATION IN POLISH LAW)
Authors:   Adam Mickiewicz University in Poznań, Poland, Szczepańska Katarzyna
Published: July 2023

The non-splitting (indivisibility) of a share constitutes one of the fundamental principles of company law. It encompasses the idea that the voting rights ('control rights') and economic interests ('economic rights' or 'ownership rights') are intrinsically bound up in a single share. In recent years, “empty voting” - a tactic allowing to decouple voting rights from economic ownership which embrace a variety of factual circumstances that ultimately result in a partial or a full separation of the right to vote at a shareholders' meeting from beneficial (i.e. economic) ownership of the shares on the meeting date to influence company's decision-making process without the intention to hold shares for a longer period of time has become interest of the European legislator. This paper investigates how the European law legal framework approaches to combat the issues caused by empty voting and thus how the principle of non-splitting (indivisibility) of shares in upheld in the EU law. The article explores the features of empty voting, characterizes various approaches to minimizing its impact on the disintegration of a share (i.e., a violation of the principle of non-splitting) and proper functioning of a company, and tries to evaluate the legislative reactions to this phenomenon at the level of EU law level – (Transparency Directive and Shareholders Rights Directive). It also discusses examples of the implementation of the measures in the Polish legal order (i.e. record date system). It is argued that already undertaken regulatory steps: disclosure and information obligations should be seen as a step forward that contributes to upholding the principle of non-splitting of shares in public companies, although they do not forbid the empty voting itself
İntrauterin Gelişme Kısıtlılığında Chitotriosidase Ölçümünün Tanısal Değeri
Authors: ULUBAY Mustafa
Published: July 2023

Amaç: İntrauterin dönemde gelişme kısıtlılığı gösteren fetüsler ile gestasyonel haftasına göre küçük doğum ağırlığına sahip fetüsler arasında, fetal kordon kanı ve maternal serum kan chitotriosidase değerlerinin arasındaki farkların araştırılması amaçlanmıştır.

Gereç ve Yöntem: İntrauterin gelişme kısıtlılığı olan fetüsler (IUGK) (n:15), yapısal olarak düşük doğum ağırlıklı fetüsler (SGA) (n:15) ve herhangi bir problemi olmayan doğum haftasına göre uygun doğum ağırlıklı fetüsler (AGA) (n:30) çalışmamıza dahil edilmiştir. Doğum sırasında fetal kordon kanı ve maternal serum kan örneklerinde chitotriosidase değerleri ölçülmüştür.

Bulgular: Özellikle intrauterin gelişme kısıtlılığı olan fetüslerin doğum sırasında alınan kordon kanlarında chitotriosidase değerinin diğer gruplara göre anlamlı derecede yüksek olduğu ortaya çıkmıştır. Fakat aynı ilişki maternal serum chitotriosidase ölçümlerinde gösterilememiştir. İstatistiksel analizlerde, kordon kanı chitotriosidase enzim değerlerinin intrauterin gelişme kısıtlılığı olan fetüslerde SGA ve AGA olan gruplara göre anlamlı derecede yüksek olduğu bulunmuştur (p:0.0001).

Sonuç: Bir fetüsde intrauterin gelişme kısıtlılığı var ise fetal kordon kanında chitotriosidase değerinin yüksek bulunacağı fakat maternal kanda ise bu farkın gösterilemeyeceği ve SGA ve AGA fetüslerde ise chitotiriosidase ölçümü arasında bir fark olmadığı ortaya çıkmıştır.
ANALYSIS OF THE EFFECT OF UNCERTAINTY IN THE MATHEMATICAL MODEL OF MAGNETIC LEVITATION ON THE CHARACTERISTICS OF THE AUTOMATIC CONTROL SYSTEM
Authors: Korobeynikov Anatoly G. , Grishentsev Alexey Yu.
Published: July 2023

Stability in the design of automatic control systems is one of the main issues, because an unstable system has no practical significance. This is due to the fact that any control system is vulnerable to interference and noise in real working environment, and the effect caused by these signals will adversely affect the expected normal output in an unstable system.

The purpose of the study is the design and analysis of an automatic control system, taking into account the requirement of robustness based on the H∞-norm.

Materials and methods. The construction of a robust automatic control system was carried out using methods based on the calculation of the corresponding H∞-norm with the involvement of methods for solving the matrix Riccati equation. MATLAB was used as a toolkit.

Research results. Under uncertainties, control algorithms are of great importance. They enable to achieve the goal of control with given requirements and possess the property of stability during the transformation of the parameters of the control object and the characteristics of the effects of various kinds of disturbances. Feedback control methods can reduce the impact of uncertainties and provide the desired performance. However, an inadequate feedback controller can result in an unstable closed system, although an initially open system is stable. In this paper, we consider the problem of designing a stabilizing controller for an automatic control system for a levitating body with uncertainties in the parameters. The initial mathematical model of magnetic levitation, which serves as an object of control, was derived on the basis of Newton’s second law and electromagnetic induction and is a second-order ordinary differential equation with parameters containing uncertainties due to exogenous or endogenous factors. According to the Earnshaw theorem, such a system, even with zero uncertainties in the parameters, is initially unstable. With the addition of uncertainties with non-zero values, the situation with achieving stability worsens significantly. Therefore, it is necessary to develop special automatic control systems. The results of studying the influence of uncertainties in the mathematical model of magnetic levitation on the characteristics of its continuous automatic control system with one input and one output (SISO-system) are presented in a graphical form.

Conclusions. The stable effect of magnetic levitation is achieved even with sufficiently large uncertainties in the mathematical model of the control object.
DEVELOPMENT OF THE METHOD OF DIRECT SYNTHESIS OF ADJUSTABLE DC ELECTRIC DRIVE
Authors: Okhotkin Grigory P.
Published: July 2023

An important advantage of subordinate coordinate control systems is that the adjustment of the regulators is performed independently and sequentially from the internal contour to the external one. The approximation of a semiconductor electric power converter by a continuous dynamic link makes it possible to analytically investigate the dynamics of a regulated electric drive and to evaluate the optimal parameters of regulators that provide the maximum dynamic performance of the electric drive.

The purpose of the study is to develop a methodology for the direct synthesis method of regulated electric drives with limiting dynamic parameters, performed according to the system of subordinate coordinate regulation.

Materials and methods. Based on the analysis of dynamic processes, mathematical and simulation models of an adjustable electric drive have been developed. The dynamics of the electric drive is described by the differential equation of the third row. The theory of differential equations was applied in the work, operator methods of system representation, direct methods of synthesis of automatic control systems were used. Calculations were performed in the MATLAB Simulink programming environment.

The results of the study. The normalization of the differential equation of the regulated electric drive allowed the equation parameters to be associated with the shape of the transition characteristic curve and the parameters of the speed controller. The exact values of these parameters have been established, providing the best forms of transients under control actions and load disturbances. It is proposed to use a proportional-integral regulator to optimize the processes through the disturbance channel, and to optimize the control processes – to introduce a passive link at the channel input by the control action. At the same time, an independent adjustment of the velocity contour to the optimum for both types of exposure is ensured. Modeling processes in the MATLAB Simulink programming environment completely coincide with the indicators given in well-known works.

Conclusions. The developed method of synthesis of doubly integrating electric drive systems made it possible to establish the analytical relationship between the parameters of the speed controller and the shape of the transition characteristic curve under control actions and under load disturbances.

To independently adjust the velocity contour to the optimum for both types of impact, it is proposed to use a PI controller to optimize the processes by the perturbation channel, and to optimize the control processes – to introduce a passive link at the channel input by the control action.

In the course of simulation modeling, it was found that the quality indicators of the transition process of the velocity contour completely coincide with the indicators used in known works.
IMPROVING ENERGY EFFICIENCY OF ELECTRICAL EQUIPMENT OF SUCKER ROD PUMPING UNITS
Authors: Artykaeva Elmira M. , Vasileva Lidia N. , Romanov Roman A.
Published: July 2023

Currently, in the country’s economy, oil production issues are the focus. In this regard, the organization of effective operation of electrical equipment of oil-producing installations with sucker rod pumps requires close attention and is very relevant.

The purpose of the work is to increase the energy efficiency of electrical equipment of sucker rod pumping units by using promising types of electric drives, as well as monitoring operation using the TRACE MODE SCADA system.

Materials and methods. In order to increase the energy efficiency of the electric drive of sucker rod pumping units, it is proposed to consider the possibility of using a valve motor with permanent magnets instead of the asynchronous motor. It has significantly improved energy and mass-dimensional indicators. It is also proposed to control the operation using the TRACE MODE SCADA system, since it has proven itself to be an effective automated control technology.

The results of the work. The article provides a comparative assessment of the operation of electric drives of sucker rod pumping units of traditional rocking machines with an asynchronous motor and a valve motor. It is shown that due to high overload capacity of the valve motor, its rated power can be 2-3 times less than that of an asynchronous motor. In addition, the power factor of the valve motor is close to 1. All this increases the efficiency of the electrical equipment of the sucker rod pumping units and, accordingly, reduces the consumption of electricity. As another option for improving the energy efficiency of electrical equipment of sucker rod pumping units, the use of a linear valve motor is proposed. The exclusion of the gearbox, belt drive and crank mechanism allows achieving higher efficiency of the entire electromechanical complex of sucker rod pumping units. The use of the TRACE MODE SCADA system in intelligent control stations makes it possible to create a controlled network with the possibility of implementing remote operator control over the technological process, switching devices on and off remotely, reading data from the database of the design system in real time; displaying information on the monitor screen; network data exchange with industrial controllers; archiving and transmitting the current values.

Conclusions. The article presents a comparative analysis of several types of electric drives based on valve motors instead of traditional asynchronous motors. The advantages of using such drives and their energy efficiency due to higher values of efficiency and power factor are shown. It is proposed to use the TRACE MODE SCADA system to control the operation of sucker rod pumping units.
SOLUTION OF THE LAPLACE EQUATION BY THE METHOD OF SEPARATION OF VARIABLES FOR A LENGTH HOLLOW CYLINDER
Authors: Afanasyev Aleksandr A. , Ivanova Nadezhda N.
Published: July 2023

The physical model of many electrical objects is a hollow cylinder of finite length. As a basis for constructing analytical models of electrical machines, linear equations of mathematical physics are used. They are the solution of the Laplace three-dimensional partial differential equation, which is widely used in analytical calculations.

The purpose of the study is to solve the Laplace three-dimensional differential equation for a hollow cylinder of finite length, which can be adapted for the electromagnetic calculation of electromechanical devices with cylindrical active parts.

Materials and methods. To solve the Laplace equation in a cylindrical coordinate system, the Fourier variable separation method was used. To obtain a non-trivial solution of the equation, eigenfunctions of the Sturm–Liouville problem were used. Dirichlet, Neumann boundary value problems of the mixed type for hollow cylinders are adapted to the electromagnetic calculation of electromechanical devices having cylindrical active parts.

The results of the study. The Laplace equation given in a cylindrical coordinate system is considered, on the basis of which the Sturm–Liouville equation with zero initial values is compiled to find eigenfunctions. The complete solution of the Lapalace equation with given boundary conditions is obtained as the sum of the solutions of two separate Dirichlet problems with different boundary conditions.

Findings. The obtained analytical expression can be used as a mathematical basis for constructing three-dimensional analytical models of electrical machines with cylindrical active parts and carrying out electromagnetic calculations of the corresponding electromechanical devices.
A SENSORLESS CONTROL METHOD OF THYRISTOR STATICAL FREQUENCY CONVERTER FOR STARTING SYNCHRONOUS MACHINE
Authors: Afanasyev Aleksandr A. , Paimurzov Evgenii G.
Published: July 2023

Relevance of study. Starting of the medium voltage synchronous machine at standstill is one of the main problems in the operation of unregulated synchronous electric drives. The optimal solution is starting the excited synchronous machine fed by the thyristor statical frequency converter. A sensorless control of the statical frequency converter for thyristor switching of load-commutated inverter to functions of synchronous machine angular rotor position in the area of zero and low speed, has not yet received a clear solution.

The purpose of this study is the design of the sensorless control method for the thyristor statical frequency converter at the synchronous machine startup under conditions of angular acceleration uncertainty.

Materials and methods. Methods of theory of electrical machines and computer mathematical simulation are used in the study.

Results of the study. The regularity between the angular rotor position and the non-conductive phase stator voltage of the synchronous machine is determined. The rotor rotation angle of the synchronous machine is defined as the ratio of the conductive state duration of the thyristor arm pair of the load-commutated inverter to the period determined from the non-conductive phase stator voltage of the synchronous machine. The sensorless control method is based on simultaneous operation of scalar control, indirect angular rotor position determination and cross-control channels. The proposed sensorless control method is tested by computer mathematical simulation of the system «thyristor statical frequency converter –synchronous machine».

Findings. The application of the considered control method was found for commercially available medium voltage thyristor frequency converters of EKRA Ltd. The considered method can be used for the sensorless control of frequency converter by different topology.
RECURRENT NEURAL NETWORK FOR CONTROLLING THE SPECTRUM WIDTH OF A NON-STATIONARY RANDOM SIGNAL
Authors: Alyunov Dmitry Yu.
Published: July 2023

The purpose of the study is to develop a recurrent neural network for detecting the moment of the beginning of the transient process of a random non-stationary signal in a sliding window. The possibility of using the apparatus of artificial neural networks (ANN) in analyzing non-stationary random processes is investigated. Rapid detection of the moment at which a non-stationary random process changes its behavior is an urgent task of electrical engineering.

Materials and methods. A comparison is made between the use of the autocorrelation function and a neural network algorithm based on a recurrent neural network to control non-stationary noise.

Results. The novelty of the study consists in developing a new algorithm for estimating the spectrum width of a non-stationary random signal based on the use of the ANN apparatus. It is shown that recurrent neural networks are capable of processing the original signal. They do not require special pre-processing and data preparation. A study of the quality of ANN operation depending on the parameters of the signals and the size of the sliding window was carried out. The ways to improve the architecture of the neural network and to enrich the data to improve the quality of the classifier are proposed.

Conclusions. It was found that there is an optimal ratio between the time of detecting a change in signal parameters and the size of the sliding window, which imposes restrictions on the choice of the latter and the method of applying the trained neural network model.