Journal of Mathematical Sciences & Computational Mathematics (JMSCM)
(ISSN Number (Online) - 2644-3368)
(ISSN Number (Print) - 2688-8300)


Volume 5 Issue1 :


A STOCHASTIC DETECTION MODELS COMPARISON IN TURBULENT FLOW EVENTS


1,*Maria Valeria Calandra & 2Julio Marañón Di Leo


1UIDET GAMEFI
Departamento de Ciencias Básicas Facultad de Ingeniería, Universidad Nacional de la Plata Calle 48 y 116, La Plata (1900), Argentina

2UIDET LaCLyFA-CTA/UNLP
Departamento de Ingeniería Aeroespacial Facultad de Ingeniería, Universidad Nacional de La Plata Calle 116 entre 47 y 48, La Plata (1900), Argentina

*Corresponding Author Email: marí[email protected]

Page Number: 1-13


The need to establish the downwind fluid dynamic field of aerodynamic bodies subjected to a given velocity field is well known, to verify their aerodynamic characteristics. In this context, different techniques allow us to establish the characteristics of the field. It is almost always necessary to carry out quantitative determinations to describe the field correctly, particularly when the field is made up of turbulent wakes. In this sense, in the experimental field, it is common to use hot-wire anemometry techniques, which have great capabilities to quantify high-frequency events. Previous work has analyzed the determination of changes in hot-wire anemometry signals for the detection of events in turbulent flows with different models, based on stochastic algorithms (CPM - Change Point Model). The present work aims to compare the results obtained previously with the application of different CPM models developed. Previously applied and evaluated measurements are used, the implementation of the models is carried out and the results are compared. All the algorithms used can detect changes in data that do not have a known distribution, i.e. non-parametric distributions, which are typical for turbulent flow field signals. Measurements of the fluctuating components of the wind tunnel velocity at a specific point are considering. The signals used correspond to periodic detachments downstream of a flow control device (Gurney mini-flap) at the trailing edge of an airfoil. The results show which are the best models to use for the experimental detection of such turbulent events in the flow field.


keywords:
: Event detection, Turbulent flow, Vortex, Change point models.


DOI: doi.org/10.15864/jmscm.5101

INVERSE SOURCE IDENTIFICATION ON PARABOLIC EQUATION WITH CAUCHY CONDITIONS AS A GENERALIZED PROBLEM OF MOMENTS


1,2María B. Pintarelli


1Departamento de Matematica de la Facultad de Ciencias Exactas Universidad Nacional de La Plata, LaPlata -1900. Argentina

2Departmento de CienciasBasicasde la Facultad de Ingenieria Universidad Nacional de La Plata -1900. Argentina

Email: [email protected]

Page Number: 14-28

We consider the problem of finding a pair of functions 𝑟(𝑥,𝑡)and 𝑤(𝑥,𝑡)that satisfy the equation 𝑤t(𝑥,𝑡) = 𝑤𝑥𝑥(𝑥,𝑡) + 𝑟(𝑥,𝑡) under Cauchy boundary conditions. We will see that an approximate solution can be found using the techniques of generalized inverse problem of moments and find dimensions for the error of the estimated solution.

keywords:
generalized moment problem; integral equations; Parabolic equation, inverse source


DOI: doi.org/10.15864/jmscm.5102

ON NEUTROSOPHIC MILDLY GENERALIZED REGULAR STAR 𝜶𝑱 - CLOSED SETS IN NEUTROSOPHIC TOPOLOGICAL SPACES


R M Samukthaa


Assistant Professor
Department of Mathematics Excel Engineering College (Autonomous), Komarapalayam, Namakkal – 637303

Email: [email protected]

Page Number: 29-40


The Neutrosophic mildly generalised regular star 𝜶𝑱- closed sets in Neutrosophic topological spaces are a new class of sets that we present in this study (briefly Neu - MGR*𝜶𝑱 - closed sets). Here, we study the concepts and discuss the properties of Neu - MGR*𝜶𝑱 - closed sets.


DOI: doi.org/10.15864/jmscm.5103

AN APPROACH TO SOLVE SOME UNSOLVED LIMITATIONS: ROUGH SET THEORY


1Anshit Mukherjee, 2,*Gunjan Mukherjee,3Kamal Kumar Ghosh


1Bachelor in Computer Science Abacus Institute of Engineering and Management Hooghly,WestBengal,India
2Department of Computational Sciences Brainware University Barasat,WestBengal,India
3Department of Science and Humanities Abacus Institute of Engineering & Management Hooghly, West Bengal,India
*Corresponding Author Email: [email protected]

Page Number: 41-82


Rough set theory is a mathematical approach to dealing with uncertainty and vagueness in data. It was introduced as a way to approximate classical sets using lower and upper bounds. Rough set theory has been applied to various domains such as data mining, knowledge discovery, machine learning, soft computing, medical analysis, synthesis of switching circuits, and civil engineering. Rough set theory can handle imprecise and noisy data by finding structural relationships and dependencies among attributes. It can also reduce redundant and irrelevant attributes and generate decision rules from data. Rough set theory is closely related to fuzzy set theory, but differs in that it uses multiple memberships instead of partial memberships to model uncertainty.Lot of research works have taken place in this domain with many fruitful outcomes that helped lot in expanding this field to much wider reach of knowledge irrespective of the domain concerned to mathematical and technological application development. In lieu of such research-oriented progress in different versatile domain, many areas of research has remained untouched as many a problem remained unsolved being shrouded under the mystery. This paper deals mainly with some of the still unsolved questions on Rough Set that are under study for new discovery and a way to overcome such limitations citing proper techniques, examples, working models, and graphs.

keywords:
consistent, scalable, machine learning, pattern recognition, decision making, artificial intelligence.


DOI: doi.org/10.15864/jmscm.5104

AN ASSESSMENT THE FINANCIAL PERFORMANCE OF MUANGKHAY WATER SUPPLY SYSTEM IN LUANG PRABANG CAPITAL, LUANG PRABANG PROVINCE


1,*Toui Xaiveeheuang,1Khampasith Thammathevo,1Sisouvanh kittavong,1Phoummixay Siharath, 2Biswadip Basu Mallik, 3Oupala Phanthasena,3Phouthasanh Sinakhone


1Environmental Engineering Department, Faculty of Engineering, National University of Laos

2 Department of Basic Science & Humanities, Institute of Engineering & Management, Salt Lake Electronics Complex, Kolkata- 700091. West Bengal. India.

3Basic Science Division, Faculty of Engineering, National University of Laos

*Corresponding Author Email: [email protected]

Page Number: 83-89


Water supply is essential and an indispensable factor in the daily life of all populations. to improve the quality of life of citizens and lead to sustainable economic and social development; the party and the government has highlighted as crucial to the development of the water sector. the Some projects have been completed implement, but some of them were not matched to technical standard. Concessionaire seeks to cancel or sell the concession contract to others because they had invested, and the return is less than ought. Therefore, to guarantee the Water Supply System's implementation under the Public Private Partnership Project. This assessment aims to study and evaluate the financial performance of MuangKhay Water Supply System, Luang Prabang City, Luang Prabang Province that invest and operate by the private sector, and Build-operate-transfer for 30 years. To do this we collect data with the private operator which cost of investment, personnel, an average of chemicals, operation fees, electricity, etc., to calculate the Payback Period, Net Present Value, Internal rate of Return, and Cost Benefit Ratio. The assessment of The estimated total income for the 30-year project is 1.877.122 USD, the estimated total expenses are 667.153 USD, the investment cost is $404.425 USD, and the net cash flow is 1.209.969 USD, investors will realize a profit in 14 years, 7 months, and 18 days, therefore, the net present value is 790.488 USD, the rate of return within the project is 6,98%, the net cash flow from operations is 1.209.669 USD, and the return on capital ratio is 1,9. As a result, investment in the water supply at the MuangKhay village cluster in Luang Prabang City, Luang Prabang Province yielded a satisfactory return

keywords:
: Assessment, financial, IRR, PPP.


DOI: doi.org/10.15864/jmscm.5105

META-ANALYSIS ON THE EFFECT OF PERCEIVED USEFULNESS AND PERCEIVED EASE OF USE OF ZOOM CLASSROOM IN TEACHING AND LEARNING AMONG NIGERIAN INSTITUTIONS OF HIGHER LEARNING


1,*Abubakar Bashar,2Muhammad Sani Abdurrahman,3Sadiq Buhari Bello


1Department of Computer Science, Waziri Umaru Federal Polytechnic Birnin Kebbi
2Department of Mathematics, Waziri Umaru Federal Polytechnic Birnin Kebbi
3Department of Computer Engineering, Waziri Umaru Federal Polytechnic Birnin Kebbi

*Corresponding Author Email: [email protected]

Page Number: 90-103


COVID-19 pandemic affected the educational sector in Nigeria and the rest of the world in early 2020 making educationalist search for substitutes for the conventional physical classroom learning style. This led so many institutions in Nigeria and abroad to adopt video conference systems (such as zoom, even though it is used by an insignificant number of academicians) to facilitate academic activities through virtual teaching and learning. More than 80% of young students have negatively been affected by their educational activities due to the closure of all schools globally because of the COVID-19 pandemic. The teaching and learning in most Nigerian institutions are based on face-face contact which was paralyzed due to the COVID-19 lockdown. Institutions are called on to adjust their pedagogical practices and adapt to the learning needs of the students beyond the classroom walls as online learning is perceived to be the best method in order to minimize direct contact. The purpose of this meta-analysis was to examine the effect of perceived usefulness and perceived ease of use on zoom classrooms towards learning motivation. A literature search was performed using prominent internet databases between 2018 to 2023. Sixteen published articles fulfilled the review requirements set for incorporation. The small amount of articles resulting from this search indicates that in recent years the use of video conferencing systems has been investigated to some higher extent in using zoom classroom. Results from the sixteen articles disclosed that zoom classroom remains a promising instructional instrument that awaits further exploration in Nigeria. To enhance the knowledge of learners in Nigerian institutions, the research proposes among other things that, adoption was limited in developing countries like Nigeria due to the factors such as limited power supply, internet subscription costs, and limited internet service.

keywords:
Meta-analysis, perceived usefulness, perceived ease of use, zoom classroom


DOI: doi.org/10.15864/jmscm.5106

MODELLING COVID-19 FLUCTUATION IN NIGERIA USING FRACTIONAL INTEGRATED GARCH MODEL


1,*WIRI, Leneenadogo,2SIBEATE, Pius U.


1Rivers State Ministry of Education, Port Harcourt Nigeria.
2Department of PRS (Statistics & EMIS Unit), Rivers State Ministry of Education, Port Harcourt, Nigeria.


*Corresponding Author Email: [email protected]

Page Number: 104-114


This study applied a fractionally integrated GARCH (FIGARCH) process in modelling daily cases of COVID-19 in Nigeria from 28 February 2020 to 23 March 2022. The time plot of the series showed the constant fluctuation in the study variable. The daily COVID-19 data was tested for stationarity using Augmented Dickey-Fuller (ADF), the series was not stationary. The Geweke and Porter-Hudak (GPH) method was used to estimate the long memory parameter d of the FIGARCH model. The daily series was stationary at a fractional differencing of order (d=0.97). The presence of long memory was also detected using the autocorrelation function. The fractionally integrated GARCH model was used to detect the period of high and low crisis. The crisis period was identified by volatility clustering and the leverage effect process. However, four models were estimated for FIGARCH models. The best model was selected based on the information criteria. Finally, the most adequate model for estimating the volatility of COVID-19 in Nigeria was the FIGARCH (1,0.97, 1) model.

keywords:
COVId-19, Fluctuation, FIGARCH model, Long-memory process, the Autocorrelation function


DOI: doi.org/10.15864/jmscm.5107