bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bipartite powers of k-chordal graphs
Authors: Chandran Sunil , Mathew Rogers 
Published: August 2021

Graph Theory
Let k be an integer and k ≥3. A graph G is k-chordal if G does not have an induced cycle of length greater than k. From the definition it is clear that 3-chordal graphs are precisely the class of chordal graphs. Duchet proved that, for every positive integer m, if Gm is chordal then so is Gm+2. Brandstädt et al. in [Andreas Brandstädt, Van Bang Le, and Thomas Szymczak. Duchet-type theorems for powers of HHD-free graphs. Discrete Mathematics, 177(1-3):9-16, 1997.] showed that if Gm is k-chordal, then so is Gm+2. Powering a bipartite graph does not preserve its bipartitedness. In order to preserve the bipartitedness of a bipartite graph while powering Chandran et al. introduced the notion of bipartite powering. This notion was introduced to aid their study of boxicity of chordal bipartite graphs. The m-th bipartite power G[m] of a bipartite graph G is the bipartite graph obtained from G by adding edges (u,v) where dG(u,v) is odd and less than or equal to m. Note that G[m] = G[m+1] for each odd m. In this paper we show that, given a bipartite graph G, if G is k-chordal then so is G[m], where k, m are positive integers with k≥4.
Surjective cellular automata far from the Garden of Eden
Authors: Capobianco Silvio , Guillon Pierre , Kari Jarkko 
Published: August 2021

Automata, Logic and Semantics
One of the first and most famous results of cellular automata theory, Moore's Garden-of-Eden theorem has been proven to hold if and only if the underlying group possesses the measure-theoretic properties suggested by von Neumann to be the obstacle to the Banach-Tarski paradox. We show that several other results from the literature, already known to characterize surjective cellular automata in dimension d, hold precisely when the Garden-of-Eden theorem does. We focus in particular on the balancedness theorem, which has been proven by Bartholdi to fail on amenable groups, and we measure the amount of such failure.
Isomorphism of graph classes related to the circular-ones property
Authors: Curtis Andrew R. , Lin Min Chih , Mcconnell Ross M. , Nussbaum Yahav , Soulignac Francisco Juan , Spinrad Jeremy P. , Szwarcfiter Jayme Luiz 
Published: August 2021

Discrete Algorithms
We give a linear-time algorithm that checks for isomorphism between two 0-1 matrices that obey the circular-ones property. Our algorithm is similar to the isomorphism algorithm for interval graphs of Lueker and Booth, but works on PC trees, which are unrooted and have a cyclic nature, rather than with PQ trees, which are rooted. This algorithm leads to linear-time isomorphism algorithms for related graph classes, including Helly circular-arc graphs, Γ circular-arc graphs, proper circular-arc graphs and convex-round graphs.
Hereditary biclique-Helly graphs: recognition and maximal biclique enumeration
Authors: Eguia Martiniano , Soulignac Francisco Juan 
Published: August 2021

Graphs and Algorithms
A biclique is a set of vertices that induce a complete bipartite graph. A graph G is biclique-Helly when its family of maximal bicliques satisfies the Helly property. If every induced subgraph of G is also biclique-Helly, then G is hereditary biclique-Helly. A graph is C4-dominated when every cycle of length 4 contains a vertex that is dominated by the vertex of the cycle that is not adjacent to it. In this paper we show that the class of hereditary biclique-Helly graphs is formed precisely by those C4-dominated graphs that contain no triangles and no induced cycles of length either 5 or 6. Using this characterization, we develop an algorithm for recognizing hereditary biclique-Helly graphs in O(n2+αm) time and O(n+m) space. (Here n, m, and α= O(m1/2) are the number of vertices and edges, and the arboricity of the graph, respectively.) As a subprocedure, we show how to recognize those C4-dominated graphs that contain no triangles in O(αm) time and O(n+m) space. Finally, we show how to enumerate all the maximal bicliques of a C4-dominated graph with no triangles in O(n2 + αm) time and O(αm) space.
Further results on maximal nontraceable graphs of smallest size
Authors: Burger Alewyn Petrus , Singleton Joy Elizabeth 
Published: August 2021

Graph Theory
Let g(n) denote the minimum number of edges of a maximal nontraceable (MNT) graph of order n. In 2005 Frick and Singleton (Lower bound for the size of maximal nontraceable graphs, Electronic Journal of Combinatorics, 12(1) R32, 2005) proved that g(n) = ⌈3n-22 ⌉ for n ≥54 as well as for n ∈I, where I= 12,13,22,23,30,31,38,39, 40,41,42,43,46,47,48,49,50,51 and they determined g(n) for n ≤9. We determine g(n) for 18 of the remaining 26 values of n, showing that g(n) = ⌈ 3n-22 ⌉ for n ≥54 as well as for n ∈I ∪18,19,20,21,24,25,26,27,28, 29,32,33 and g(n) = ⌈ 3n2 ⌉ for n ∈ 10, 11, 14, 15, 16, 17. We give results based on ''analytic'' proofs as well as computer searches.
A bound on the number of perfect matchings in Klee-graphs
Authors: Cygan Marek , Pilipczuk Marcin , Škrekovski Riste 
Published: August 2021

Combinatorics
The famous conjecture of Lovász and Plummer, very recently proven by Esperet et al. (2011), asserts that every cubic bridgeless graph has exponentially many perfect matchings. In this paper we improve the bound of Esperet et al. for a specific subclass of cubic bridgeless graphs called the Klee-graphs. We show that every Klee-graph with n ≥8 vertices has at least 3 *2(n+12)/60 perfect matchings.
The determining number of Kneser graphs
Authors: Cáceres José , Garijo Delia , González Antonio , Márquez Alberto , Puertas Marıa Luz 
Published: August 2021

Graph Theory
A set of vertices S is a determining set of a graph G if every automorphism of G is uniquely determined by its action on S. The determining number of G is the minimum cardinality of a determining set of G. This paper studies the determining number of Kneser graphs. First, we compute the determining number of a wide range of Kneser graphs, concretely Kn:k with n≥k(k+1) / 2+1. In the language of group theory, these computations provide exact values for the base size of the symmetric group Sn acting on the k-subsets of 1,..., n. Then, we establish for which Kneser graphs Kn:k the determining number is equal to n-k, answering a question posed by Boutin. Finally, we find all Kneser graphs with fixed determining number 5, extending the study developed by Boutin for determining number 2, 3 or 4.
Sequence variations of the 1-2-3 conjecture and irregularity strength
Authors: Seamone Ben , Stevens Brett 
Published: August 2021

Graph Theory
Karonski, Luczak, and Thomason (2004) conjecture that, for any connected graph G on at least three vertices, there exists an edge weighting from 1, 2, 3 such that adjacent vertices receive different sums of incident edge weights. Bartnicki, Grytczuk, and Niwcyk (2009) make a stronger conjecture, that each edge's weight may be chosen from an arbitrary list of size 3 rather than 1, 2, 3. We examine a variation of these conjectures, where each vertex is coloured with a sequence of edge weights. Such a colouring relies on an ordering of E(G), and so two variations arise - one where we may choose any ordering of E(G) and one where the ordering is fixed. In the former case, we bound the list size required for any graph. In the latter, we obtain a bound on list sizes for graphs with sufficiently large minimum degree. We also extend our methods to a list variation of irregularity strength, where each vertex receives a distinct sequence of edge weights.
Psychosocial impact of COVID-19 on the Brazilian elderly population
Authors: De Castro Larissa Pinheiro , De Souza Lúcia Aparecida , Da Fonseca Hortência Gueve , Modesto João Gabriel , Pernambuco Marília Lopes , Lima Clara Mariana Gonçalves , Pagnossa Jorge Pamplona 
Published: August 2021

ABSTRACT
COVID-19 is a highly contagious disease caused by the new betacoronavirus of severe acute respiratory syndrome 2 (SARS-CoV-2). The high mortality of the disease occurs in a small portion of the infected population, especially in elderly individuals. The main measure adopted in Brazil to contain the virus is social isolation and this can have an impact on the mental health of the elderly population. This study aims to provide an educational intervention, understanding the repercussions that the COVID-19 pandemic has on the routine of the elderly. This is a study carried out through documentary analysis, based on bibliographic reviews, national and international, of specialists in the subject. It was found that mandatory social isolation causes uncertainties, insecurity, fear, and sometimes low self-esteem, which can lead to an emotional imbalance during this period of the pandemic of the new coronavirus, causing the elderly to become more fragile. Therefore, it is important to give special attention to this group based on specific health plans during this period together with the relatives of these elderly, which will enable better results in coping with COVID-19 in this group, besides preventing a spike in the incidence of mental health-related diseases.

RESUMEN
La COVID-19 es una enfermedad altamente contagiosa causada por el nuevo betacoronavirus del síndrome respiratorio agudo severo 2 (SARS-CoV-2). La elevada mortalidad de la enfermedad se produce en una pequeña parte de la población infectada, especialmente en individuos de edad avanzada. La principal medida adoptada en Brasil para contener el virus es el aislamiento social y esto puede tener un impacto en la salud mental de la población anciana. Este estudio tiene como objetivo proporcionar una intervención educativa, entendiendo las repercusiones que la pandemia de COVID-19 tiene en la rutina de los ancianos. Se trata de un estudio realizado a través de un análisis documental, basado en revisiones bibliográficas, nacionales e internacionales, de especialistas en el tema. Se constató que el aislamiento social obligatorio provoca incertidumbres, inseguridad, miedo y, a veces, baja autoestima, lo que puede llevar a un desequilibrio emocional durante este período de la pandemia del nuevo coronavirus, provocando la fragilidad de los ancianos. Por lo tanto, es importante dar una atención especial a este grupo en base a planes de salud específicos durante este período junto con los familiares de estos ancianos, lo que permitirá obtener mejores resultados en el afrontamiento de la COVID-19 en este grupo, además de evitar un repunte en la incidencia de enfermedades relacionadas con la salud mental.
The Role of Reading in The Process of Foreign Language Teaching
Authors: Farrukh Ilyosov  
Published: August 2021

Learning a foreign language contributes to the development of cognitive functions of the human psyche. In the process of mastering a foreign language practicing different memorization techniques, formed philological thinking, expand knowledge of reality. Especially reading helps to develop all these skills. At the initial stage of learning, reading comes to master the technique of reading aloud, and only to some extent, self-reading. As reading is one of the most important means of obtaining information and it has a significant place in the life of an educated person, this article deals with the role of reading in the process of teaching the foreign language
Taxonomic Analysis of Hunting Milk Markers in Uzbekistan
Authors: Rustamovich Rayimov Avaz , Rakhimovich Rakhmonov Rashid , Kenjayevana Nurova Hikoyat , Qizi Rustamova MoxinurAvaz 
Published: August 2021

Of the 19 species of mammals allowed to hunt in Uzbekistan, 13 species have been identified in Bukhara region. In particular, the taxonomic analysis of mammals hunted in the region revealed that 5 species of mammals were hunted on the basis of appropriate permits, 4 species of mammals were hunted illegally. Of these, 3 species (Canis lupus, Felislibyca, Ondatrazibethicus) and 1 species (Gazellasubgutturoza) were identified as hunting in the Red Data Book of the Republic of Uzbekistan. [1].
DOES THE CHOICE OF LANGUAGE IN TESTS HAVE AN IMPACT ON GENDER EQUALITY IN PRIMARY EDUCATION? A CASE STUDY IN SENEGAL
Authors: Chazeaud Alexandre 
Published: August 2021

Purpose: The present study analyses the possible impact on gender equality when using a language familiar to students in tests at primary schools in Sub-Saharan Africa where a European language is the unique medium of instruction and assessment.
Methodology: To this aim, students at grades 3 and 6 (83 girls and 66 boys) in primary schools in rural Senegal were given two different tests: Mathematics problem-solving tasks and multiple-choice questions of Social Sciences. They were divided at random into a control group if they received the tests in Seerer, the local language familiar to them, or French, the sole official language in the Senegalese education system. After data collection, results were codified for analysis considering two variables: Gender and grade. First, we calculated both the percentage of students who scored the set mark and those who obtained the highest scores. Second, we checked for statistically significant differences between groups by means of One-Way-ANOVA and Tukey tests.
Findings: Although Seerer as language of tests was found to benefit both genders, results suggest that its use may especially determine girls’ success at school: Girls in the experimental group obtained higher results than girls in the control group, especially the youngest, and many reached the highest scores.
Unique contribution to theory, practice and policy: Findings suggest that first, the use of a language familiar to students in tests seems to have positive effects on their academic results, and second, that it may play a role in bridging the gap between genders in some education models thanks to the evident benefits for girls, especially young ones. Such results might be taken into consideration by education authorities together with other existing examples to introduce local languages in the education system of Senegal and other Sub-Saharan countries where only a European language is employed, as it seems to contribute to reaching gender equality in education. We suggest that local languages could be used in tests from the lower levels of primary education in bilingual programs, thus favouring transfer of linguistic skills and content from the local to the European language, and increasing school success
INFLUENCE OF HUMAN RESOURCE MANAGEMENT PRACTICES ON THE PERFORMANCE OF HEALTH WORKERS IN KIAMBU COUNTY, KENYA
Authors: Mutwiri Jacob , Mwangi Eunice , Edwin Osiyel 
Published: August 2021

Purpose: The general objective of the study was to establish the role of human resource management practices on the performance of health workers in Kiambu County, Kenya.
Methodology: The study adopted cross sectional research design, using both descriptive quantitative and qualitative techniques. The study targeted managers and workers of four hospitals which were purposefully chosen. The data was collected by administering questionnaires to the respondents and conducting KII to the managers. The data was analyzed using SPSS V27. The data was presented using tables and charts to summarize responses. For further analysis and comparison, the generated quantitative reports were subjected through tabulations, percentages, measure of central tendencies, correlation coefficient, chi square test, and inferential statistics.
Findings: The study reviewed that training opportunities and performance management practices improves staff motivation and performance (mean of 4.23, and 4.13). Planning (2.66) was biggest hindrances to utilizing training to improve performance. The managers were not well trained on using appraisals, ratings and feedback (2.06) for performance management. The institutions were not embracing performance culture (2.60), and using it for continuous improvement (1.82). Additionally, the study showed that hospitals did not carry out performance measurement regularly (2.81) and the systems for data collection were inadequate (2.43).
Unique contribution to theory, practice and policy: The study showed that human resource management practices improve health workers performance. Institutions should formulate and review policies to support human resource management practices that improve performance of the health workers
EVALUATION OF PLANNING AND MANAGEMENT OF DISTANCE EDUCATION. ACRITICAL LITERATURE REVIEW
Authors: Kimani Cassan 
Published: August 2021

Purpose: The rapid technological changes in education today have become paramount towards meeting our educational demands for the 21st century. The emerging trend in the use of Information Communication Technology has helped in bringing down the traditional barriers of access to higher education leading to access of quality education and training. This has provided learners with opportunities for lifelong learning and meaningful participation in the world of work and society as productive citizens through distance learning. The general objective of the study was to conduct an evaluation of planning and management of distance education.
Methodology: The paper used a desk study review methodology where relevant empirical literature was reviewed to identify main themes and to extract knowledge gaps.
Findings: From the study findings, it is concluded that little difference was found in the community found in the web-based course in comparison with their traditional courses. With the special characteristics associated with distance education, special measures should be taken to see that communities are established. Choosing exercises or activities that are collaborative will increase the potential for developing a community of learners. In addition, frequent use of online discussion or bulletin boards will also assist with this endeavor. Professional development on how to build a community for traditional and web-based courses is needed.
Recommendations: The study recommends that is a need for assessment of whether or not faculty are adequately prepared to teach at a distance, especially in light of the fact that faculty tend to teach in the same manner in which they were taught, is definitely warranted. A check list that would help identify the preparedness of the faculty member before they are responsible for distance student learning would help the students and program. Instructor training should be required before faculty are considered qualified to teach distance courses which necessitates the discovery of quality training programs. Support staff that is needed to assist faculty members when making the transition from a face-to-face to a virtual environment should be identified
ANALISIS HUBUNGAN MODAL KERJA DENGAN NET PROFIT MARGIN PT. BASILAM INDAH KABUPATEN BATUBARA
Authors: Sriwiyanti Eva 
Published: August 2021

Abstract
This study aims to analyze the relationship between working capital and net profit margin. Descriptive quantitative method where quantitative data that has been processed, the results are described in sentences. The data analysis technique used is quantitative descriptive analysis with reference to the calculation results of working capital and net profit margin. The results of this study indicate that the value of the Current Ratio (CR) in 2017 is 2.4%. in 2018 the value of the Current Ratio (CR) increased to 3.8%. Then in 2019 the Current Ratio (CR) value again increased to 7.6%. The difference in the Current Ratio (CR) value from 2017 to 2018 is 1.4%. The difference in the Current Ratio (CR) value from 2018 to 2019 is 3.8%. This means that the value of the Current Ratio (CR) has increased every year.
The value of Net Profit Margin (NPM) in 2017 is 6%. In 2018 the Net Profit Margin (NPM) value increased to 7%. Then in 2019 the Net Profit Margin (NPM) value again increased to 8%. The difference in the value of the Net Profit Margin (NPM) from 2017 to 2018 is 1%. The difference in the value of the Net Profit Margin (NPM) from 2018 to 2019 is 1%. This means that the value of Net Profit Margin (NPM) has increased every year.

Keywords : Modal Kerja; Net Profit Margin,
Photocatalytic activity of Ag-Ag3PO4/Cellulose aerogel composite for degradation of dye pollutants under visible light irradiation
Authors: Nguyen Thi Hoa  , Nguyen Trung Tien  , Le Hong Phong  , Vu Van Tai  , Pham Xuan Nui  
Published: August 2021

In this research, Ag-Ag3PO4/Cellulose aerogel composite was synthesized using hydrothermal reduction and freeze-drying methods. By combining the photocatalytic activity of the semiconductor Ag-Ag3PO4 and cellulose aerogel synthesized from agricultural waste sources, the synthesized Ag-Ag3PO4/Cellulose aerogel composite has overcome the disadvantages of pure Ag3PO4 and significantly improved the photocatalytic activity. Structural characteristics, morphology, surface area of the materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption and UV–vis diffuse reflectance spectroscopy (UV-vis DRS) methods. From the obtained results, composite has narrow bandgap energy (2.275 eV) and excellent catalytic performance in the photodegradation of dye pollutants (99% MB and 77% RY 145 degraded after 4 h, and only a minor change in the efficiency observed after four consecutive tests). It demonstrates the development of new catalysts made from agricultural waste sources that show high stability, ease of fabrication and can operate in natural light for environmental remediation.
BEST PRACTICE MENGEMBANGKAN KOMPETENSI SPIRITUAL KKG PAI MELALUI KAJIAN AL- QUR’AN
Authors: MARDIYATUN MARDIYATUN 
Published: August 2021

Pengalaman terbaik ini berawal dari kegiatan rutinitas KKG Pendidikan Agama Islam yang dilaksanakan satu bulan sekali sejak tahun 2017. Kegiatan ini terkesan jalan ditempat. Kegiatan yang monoton membuat kebosanan sehingga menurunnya daya tarik untuk aktif di dalamnya. Sebagai salah satu upaya untuk mengembangkan ruh spiritual kegiatan KKG, maka kegiatan tersebut diawali melalui kajian al-Qur’an. Harapan dari kajian al- Qur’an ini kompetensi religius GPAI semakin meningkat. Adapun metode yang digunakan dalam kegiatan best practice ini ialah dengan dikriptif kualitatif dimana data yang diungkapkan dan dijelaskan secara obyektif. Mengenai langkah-langkah yang dilakukan dalam kajian ini adalah pertama membaca dengan taril diurutkan dari yang pertama kali datang sampai terakhir dengan masing-masing dua ayat. kedua menguarikan hukum bacaan pada ayat terakhir. ketiga mengartika perkata menuju per ayat kemudian mengeplosari isi kandungan dari ayat terahkir. Hasil yang dapat dimafaatkan dari kajian al-Qur’an tersebut guru aktif hadir dan semakin lancar dalam membaca mengartikan arti perkata per ayat dan mampu menggali isi kandungannya. Langkah seperti ini juga ditiru oleh guru ketika melaksakan KBM di kelas. Mereka para guru mengakui efektifitas dan mampu menambah kompetensi religius sebagai guru PAI.