VFAST Transactions on Mathematics

Published by VFAST
Online ISSN: 2411-6343
Publications
Effect of outflow position
Display of the meshing of the case study 3. Analysis and results. 3.1. Effect of outflow position. Series of simulations were conducted by varying the position of outflow (outflow outside and outflow transition) in the peak summer conditions. (Table 4).  
Article
The research presented in this article deals with the analysis of thermal and airflow patterns in a traditional compact urban fabric called 'Ksar' located in the city of Timimoun in the South western part of the Algerian Sahara. It focuses on a particular typology of urban transitional spaces which is "a covered walkway". The aim of this research is to study the thermal and airflow characteristics of these particular spaces which affect the comfort of pedestrians and influence the ambiantal conditions of neighboring houses as well. The methodology conducted in this study consists principally in applying a computational fluid dynamics model to simulate the thermal airflow behavior of a transitional space. The computational fluid dynamics software, Fluent 6.3.26 is used for the simulation of the air flow and the temperature field traversing the streets. The results indicate that under peak Summer conditions, weak and strongly fluctuating air movements characterize the walkway and for perpendicular flow, the temperature generally decreases with an increase in velocity. Areas near the passage entrance are more affected by adverse wind conditions than other areas remote from it.
 
Article
In this paper we investigate a characterization of a Banach lattice algebra with unit to be represented as an AM-f-algebra. We also consider, for a locally compact Hausdorff topological space L and a Banach lattice space A, the identification of C b (L, Z(A)) with the center Z(C 0 (L, A)) of C 0 (L, A).
 
Article
The study presents numerical and approximate analytical approximations to a model of population dynamics with unbounded mortality function. The mathematical model involves a nonlocal boundary condion. A finite difierence method is implemented for the numerical solution while the homotopy analysis method (HAM) is applied to obtain the approximate series solution. The HAM solution contains an auxiliary parameter which provides a convenient way of controlling the convergence region of series solution. Results are presented for typical test problem provided in literature. Comparison of the results of both methods show validity and eficiency of the methods.
 
Article
The number of matrices avoiding certain types of matrices is NP-hard in general. In this paper the binary matrices are considered. In particular, the problem of finding the total number of special binary matrices avoiding some types of 2 × 2 matrices is the main objective of this paper. The solution of the problem is given under some constraints as well as under general situation. The formula for the special binary matrices is obtained for total count of matrices of order n × k and also obtained the formula for special binary matrices avoiding some matrices of order 2 × 2. The formula is obtained in terms of the Catalan numbers.
 
Article
In this paper we are interested to find teleparallel proper homothetic vector fields over the Lorentzian manifold of special axially symmetric static spacetime. For the purpose we applied teleparallel Lie derivative to the metric for homothetic equations and obtained ten coupled non linear differential equations. These equations are then solved for each possibility of the metric functions and it comes out that only in one case teleparallel proper homothetic vector fields exist for the special choice of metric functions. The spacetime admit eight dimensional teleparallel homothetic vector fields in which one is proper teleparallel homothetic vector and remaining seven are teleparallel Killing vector fields
 
Article
In this paper we are searching for teleparallel Killing vector fields of special axially symmetric static spacetimes in teleparallel theory of gravitation by using direct integration and algebraic techniques. After thorough investigations, the whole problem is divided into three cases under different constraints. Two of the said cases give contradiction, while one of them gives the solution of the system comprising the killing equations in the form of killing vector fields. The dimension of the killing symmetry in this case is 10.
 
Article
In this study; experimental measurement data were performed for probability analysis. Geogrids are crucial reinforced material for civil engineering applications such as highway base/subbase reinforcement, railway ballast reinforcement and retaining walls. In this study, the cumulative distribution function was formed to estimate the probability of collapse risk of the highways. Probability density functions were calculated with the help of lognormal mean and lognormal standard deviation values of highway displacement points. The cumulative distribution functions were generalized and the probability of the damage was shown. With the results of this work; damage possibility can be estimated for any highway reinforced with geogrid which has same features such as 30x30mm, 40x40mm and 50x50mm etc.
 
Article
In this study, the cumulative distribution function was formed in order to estimate the probability of earthquake damage risk of the residential buildings. Nonlinear Pushover analysis was performed to 25 reinforced concrete residential buildings. The information regarding the buildings was taken from their projects. A 3D computer model was drawn for each building and analysis was applied to these models. 4 damage limits (slight, moderate, extensive and complete) and 5 damage zones (undamaged, slight, medium, extensive and collapse) were determined on the modal capacity curves of the buildings. Probability density functions were calculated with the help of lognormal mean and lognormal standard deviation values of limit states. The cumulative distribution functions were generalized and the probability of the damage was shown. With the results of this work; damage possibility can be estimated for any reinforced concrete residential building which has same features such as soil type, story height, irregularities, soft story etc.
 
Article
Stability is one of the most important concepts in Discrete Dynamical Systems. Behaviour of orbits in the neighbourhood of xed points can tell much about the behaviour of the system. Although in literature there are some computer codes to nd stability types of the xed points, they are generally lack of non-hyperbolic xed points for one-dimensional models and center manifolds for two-dimensional models. We give Mathematica codes for the stability of one-dimensional and two-dimensional models with non-hyperbolic cases and center manifolds. These codes will be useful for whom dealing with real world problems including population growth, compound interest and annuities, radioactive decay and pollution control etc.
 
Flow chart.
Article
The aim of this paper, to analyze stability analysis of SEIVHR epidemic model with generalized non-linear incidence rate that spread in the host population horizontally. First, we formulate the model and find its basic reproduction number. Two equilibrium exists, namely; the disease free and endemic equilibrium. The disease free equilibrium is stable both locally and globally when the threshold quantity less than unity. The endemic equilibrium is locally and globally asymptotically stable when the threshold exceeds unity. Finally, we show some numerical results for the proposed model.
 
Article
From the fundamental theorem of homomorphisms, it is well known that any homomorphism of groups (or rings or modules or vector spaces and of general universal algebras) can be decomposed as a composition of a monomorphism and an epimorphism. This result can also be extended to general functions defined on abstract sets; that is, any function can be expressed as a composition of an injection and a surjection. The main theorem in this paper called ‘Fundamental Theorem of Functions’ provides the uniqueness of such a decomposition of functions as a composition of an injection and a surjection. The uniqueness in this theorem is proved upto the level of associates by introducing the notion of an associate of functions.
 
Article
The main motive of this paper is to find an upper bound of the fourth Hankel determinant H4;1 (f) for a subclass S; with hyperbolic domain.
 
Article
Let RL ; SL and CL represents the families of multivalent bounded turning, multivalent starlike and multivalent convex functions that are subordinated with Bernoulli lemniscate in the open unit disk E = fz : jzj < 1g : In this particular paper our goal is to …nd the upper bounds of Hankel's thrid order determinant for the above mentioned families.
 
Top-cited authors
Djaffar Semmar
Lamia Khelifi
  • Saad Dahlab University
Rafik Bensalem
  • École Polytechnique d'architecture et d'urbanisme (EPAU)
Ruşen YILMAZ
  • Recep Tayyip Erdoğan Üniversitesi