Investigation on the temporal evolution of the covid’19 pandemic: prediction for Togo

OMS-Vol. 4 (2020), Issue 1, pp. 273 – 279 Open Access Full-Text PDF
Komi Agbokou, Kossi Gneyou, Kokou Tcharie
Abstract: A state of health emergency has been decreed by the Togolese government since April 01 for a period of 3 months, with the introduction of a curfew which ended on June 9, following the first case of contamination of the corona Sars- Cov-2 in Togo, case registered on March 06, 2020. This first wave of contamination started from March 19. The data observed in Togo are cases tested positive and which are cured using a protocol based on the combination of hydroxychloroquine and azithromycin. This manuscript offers a forecast on the number of daily infections and its peak (or maximum), then the cumulative numbers of those infected with the covid’19 pandemic. The forecasts are based on evolution models which are well known in the literature, which consist in evaluating the evolution of the cumulative numbers of infected and a Gaussian model representing an estimate of the number of daily infections for this first wave of contamination. over a period of 8 months from the sample of observed data.
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Next-generation matrices and basic reproductive numbers for all phases of the Coronavirus disease

OMS-Vol. 4 (2020), Issue 1, pp. 261 – 272 Open Access Full-Text PDF
Gabriel Obed Fosu, Emmanuel Akweittey, Albert Adu-Sackey
Abstract: During the early phase of Covid-19, the transmissibility of the coronavirus disease was estimated using the classical SIR and SEIR models. However, with the advent of some controlling measures in its informative stages, these classical compartmental models have been ameliorated to provide accurate insight of the coronavirus disease. The paper seeks to derive the basic reproductive formulas for these improved models using the matrix approach. These transmissibility equations detail the dynamics of the coronavirus disease for all phases of the pandemic; either the infected population is on lockdown or not; either infectious persons are quarantined or not; either a vaccination program has been rolled out or yet to be rolled out. With the availability of data, any of these transmissibility equations could be adopted to report on the endemicity of the coronavirus disease.
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Von Neumann-Jordan constants in quasi-Banach spaces

OMS-Vol. 4 (2020), Issue 1, pp. 253 – 260 Open Access Full-Text PDF
Qi Liu, Shaomo Zhuang, Yongjin Li
Abstract: We introduce the generalized von Neumann-Jordan constant of a quasi-Banach space \(X\). Also, the quasi-Hilbert characteristic is introduced. An attempt has been made to investigate the relationship between them. At the end, a characterization of uniformly non-square is given.
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Foreign vector measures

OMS-Vol. 4 (2020), Issue 1, pp. 248 – 252 Open Access Full-Text PDF
Abalo Douhadji, Yaovi Awussi
Abstract: We study the foreign measures in general by proving all operations possibilities with their characteristic relation \( \perp \) and deduce that the set of foreign vector measures is a subset of bounded vector measures; stable par linear combination.
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Valuations and their generalizations for UP-algebras

OMS-Vol. 4 (2020), Issue 1, pp. 220 – 239 Open Access Full-Text PDF
Siriwan Pawai, Tararat Khamsang, Aiyared Iampan
Abstract: In this paper, we introduce the notions of a weak pseudo-valuation, a \(0\)-weak pseudo-valuation, a weak valuation, a near pseudo-valuation, a near valuation, a pseudo-valuation, and a valuation and induce a pseudo-metric without triangle inequality, a quasi pseudo-metric, a pseudo-metric, and a metric by some these mappings on a UP-algebra. We also prove that the binary operation defined on a UP-algebra is uniformly continuous under the induced metric by a valuation in some conditions.
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Existence of the golden ratio in Tanjavur Brihadeeshwarar temple

OMS-Vol. 4 (2020), Issue 1, pp. 211 – 219 Open Access Full-Text PDF
C. Velmurugan, R. Kalaivanan
Abstract: In this study, we discussed the existence of golden ratio in Brihadeeshwarar temple, Tanjavur, Tamil Nadu, India, built in 1010 AD. It is listed on the UNESCO’s world heritage site of the Chola temples in southern India. This temple represents an outstanding creative achievement in the architectural idea of the pure form of the Dravida temples. Golden ratio has great influence in architecture, mathematics and art. We analyzed existence of the Golden ratio in structural design of Tanjavur Brihadeeshwarar temple prakaram. We used the Phi Grid and Phi Spiral software to measure the golden ratio and verified our result.
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On a generalization of KU-algebras pseudo-KU algebras

OMS-Vol. 4 (2020), Issue 1, pp. 200 – 210 Open Access Full-Text PDF
Daniel A. Romano
Abstract: As a generalization of KU-algebras, the notion of pseudo-KU algebras is introduced in 2020 by the author (D. A. Romano. Pseudo-UP algebras, An introduction. Bull. Int. Math. Virtual Inst., 10(2)(2020), 349-355). Some characterizations of pseudo-KU algebras are established in that article. In addition, it is shown that each pseudo-KU algebra is a pseudo-UP algebra. In this paper it is a concept developed of pseudo-KU algebras in more detail and it has identified some of the main features of this type of universal algebras such as the notions of pseudo-subalgebras, pseudo-ideals, pseudo-filters and pseudo homomorphisms. Also, it has been shown that every pseudo-KU algebra is a pseudo-BE algebra. In addition, a congruence was constructed on a pseudo-KU algebra generated by a pseudo-ideal and shown that the corresponding factor-structure is and pseudo-KU algebra as well.
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A modified efficient difference-type estimator for population mean under two-phase sampling design

OMS-Vol. 4 (2020), Issue 1, pp. 195 – 199 Open Access Full-Text PDF
A. E. Anieting, J. K. Mosugu
Abstract: In this article, modified difference-type estimator for the population mean in two-phase sampling scheme using two auxiliary variables has been proposed. The mean squared error of the proposed estimator has also been derived using large sample approximation. The efficiency comparison conditions for the proposed estimator in comparison with other existing estimators in which the proposed estimator performed better than the other relevant existing estimators have been given.
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Generalized the Liouville’s and Möbius functions of graph

OMS-Vol. 4 (2020), Issue 1, pp. 186 – 194 Open Access Full-Text PDF
Hariwan Fadhil M. Salih, Shadya Merkhan Mershkhan
Abstract: Let \(G = (V,E)\) be a simple connected undirected graph. In this paper, we define generalized the Liouville’s and Möbius functions of a graph \(G\) which are the sum of Liouville \(\lambda\) and Möbius \(\mu\) functions of the degree of the vertices of a graph denoted by \(\Lambda(G)=\sum\limits_{v\in V(G)}\lambda(deg(v))\) and \(M(G)=\sum\limits_{v\in V(G)}\mu(deg(v))\), respectively. We also determine the Liouville’s and Möbius functions of some standard graphs as well as determining the relationships between the two functions with their proofs. The sum of generalized the Liouville and Möbius functions extending over the divisor d of degree of vertices of graphs is also given.
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