Ravindra Boojhawon

• University of Mauritius

This study compares and evaluates the effectiveness of two optimization algorithms, Genetic Algorithm (GA) and Differential Evolution (DE), in determining the optimal headway values for Light Rail Vehicles (LRVs) at stations. The aim is to minimize both passenger waiting time and operational costs for LRT systems. Both algorithms use a standard cos...

Social media has gained importance in social and business sectors. It is capable of creating value with its rich information content and real-time dissemination of information from live human sensors. The role of these social sites cannot be ignored in information-intensive systems like the tourism business systems. This study presents a case study...

Forecasting solar radiation and UV index accurately have proven in various studies to be crucial in this evolving world where solar energy is being exploited to its core for various applications. The objective of this paper is to apply different artificial neural network architectures to the modelling of the two monthly time series data aforementio...

This chapter lays the theoretical foundation governing solar radiation processes and variations on both spatial and temporal scales. The origin of the insolation parameter in the Sun’s core, its journey to the Earth’s atmosphere, the interaction with the atmosphere, and its conversion into electricity in photovoltaic modules are discussed. The spat...

Identification of optimum locations for the placements of solar photovoltaic power plants necessitates the consideration of multiple factors, ranging from climatic suitability, technical appropriateness of the land and the legal conforming use of the chosen site. In this chapter, we propose a framework that would enable countries to efficiently har...

Proper land planning and management in terms of agro-suitability of crops and adequate placement of solar photovoltaic and thermal technologies require a knowledge of how the solar insolation parameter varies on spatial and temporal scales. In this chapter, we explore methodologies including satellite remote sensing, Numerical Weather Prediction (N...

Rooftop photovoltaic and solar water heating technologies have enormous potential to decrease reliance on fossil fuel sources for domestic energy needs. Decarbonizing the domestic sector through solar energy technologies holds the promise of a more resilient, reliable, and affordable clean energy future. In this chapter, we explore both solar energ...

Economic growth and population expansion in Mauritius have driven unprecedented rates of development. Most notably, increased urbanization of flood-prone regions has exacerbated challenges around resilience and vulnerability to recurrent flooding. We implement a multi-criteria model consisting of a physical-oriented, a social-oriented and an econom...

Mauritius relies heavily on fossil fuel imports to satisfy the energy requirements of its population. Urged by policies to address climate change at the national and international levels, the government is committed to promote sustainable development, with emphasis laid on reducing greenhouse gas emissions. Consequently, we provide an assessment of...

Mauritius is a Small Island Developing State (SIDS) with a high population density and increasing agricultural, urban and infrastructural demands, superimposed over limited physical resources. Soil and coastal erosion are recognized as an important environmental challenge facing the island. Here we review the studies on soil erosion over the past t...

Introduction:Recent outbreaks of Avian Influenza A (H5N1) in Asia, Europe and Africa have highlighted the pandemic threat that the H5N1 virus represents. Although human-to human transmission is not yet occurring on an epidemic scale, the virus can acquire this capacity through mutation or reassortment with a human influenza A virus. No country, inc...

In this paper, an analytical framework is developed using fuzzy logic to evaluate optimal sites for wind, solar and hybrid wind-solar farms; using criterial components for energy optimization through climatological, topographic and human factors. The model is applied through a case study to the island of Mauritius which bears a highly complex topog...

Objective: This clinical study monitored the effect of eating cooked Moringa oleifera leaves on the blood pressure (BP) of healthy participants in view of the perception that consumption of Moringa is associated with an increase in blood pressure, which is contradictory to the findings from the literature. Methods: A random sample of 41 healthy par...

A new hybrid forecasting tool is developed in this study which makes use of satellite remote sensing data of surface solar irradiation coupled to a Double Exponential Smoothing time series model. The prediction capabilities of the Double Exponential Smoothing model are reported to be higher than the ARMA and NAR-Neural Network. The mean absolute pe...

The magnitude of non-communicable diseases epidemic in Mauritius heralds the need for increased attention. One of the key strategies includes the optimal use of nutritionally and medicinally rich indigenous crops, as a means of curbing the impact of this epidemic. The purpose of this study was to explore the Moringa oleifera leaves and pods consump...

This study presents a high-resolution and multi-temporal drought climatology for Mauritius based on calculated standardized precipitation index (SPI) using mean monthly rainfall for the period 1953–2007. A monthly mean SPI varying from +3.4 to –2.7 indicates the occurrence of extremely wet and dry conditions, and collocated SPI indicates more frequ...

Tropical and subtropical islands benefit from a wide spectrum of renewable energy resources and advancement in technology has made it feasible for harnessing these clean and abundant energy sources. Mauritius being located in the tropical belt, receives plenteous sunshine all year round. Consequently, to provide assistance to the Government and oth...

Determining economically viable and highly efficient strategic locations for utility-scale solar power plants is a costly procedure that depends on several factors. This paper investigates the spatial suitability for installations of ground-mounted solar farms based on legal, social, technical, economic, environmental and cultural perspectives thro...

The tropical island of Mauritius (20.3°S, 57.6°E), situated in the southwestern Indian Ocean, is blessed with abundant sunshine throughout the year. In this study, eleven regression models grouped into three main categories: sunshine-based, temperature-based and hybrid-parameter-based are investigated using twenty-nine years meteorological data whi...

Many higher education institutions today offer online delivery as an alternative or addition to provide more flexibility to learners. However, students being confronted with such services come with different expectations to what that means to their learning paths and behaviours. Learning Analytics is a rather new and innovative way of making studen...

Small island states are vulnerable to soil erosion due to fragile natural resource bases and, particularly in tropical environments, erosive rainfall. Few studies, however, provide erosion risk assessments for small islands upon which conservation strategies and land use planning can be based. Investigations on Mauritius in the tropical Indian Ocea...

Mauritius is a volcanic island with a raised interior where extreme rainfall events dominate rainfall erosivity. Intra-event characteristics of the 120 highest erosive events at six selected locations between 2004 and 2008 were analyzed to provide the first detailed intra-storm data for a tropical island environment. On Mauritius, spatial variation...

Mangroves are important coastal ecosystems in tropical areas. In Mauritius, there has been studies on understanding the role of this ecosystem. However, it is also essential to have information on its coverage and distribution. The aim of the present study was to investigate on the forest structure at two sites in the south east coast (Anse Jonchée...

This paper focused on the statistical modelling of wind speed data observed at two locations in Mauritius using some standard probability distribution functions (PDF). The objective was to determine the best PDF which can represent the data. The PDFs considered were Weibull, Rayleigh, Lognormal, Gamma, Normal and Frechet. The parameters for each PD...

Climate change has been a burning issue since quite a long time and its effects can be perceived around the world. Carbon dioxide (CO2) is the main driver of climate change among other greenhouse gases (GHGs). Despite increasing emissions, CO2 is fortunately also absorbed or sequestered by plants and other biotic media which form the carbon sinks....

The road transport sector is one of the major contributors of greenhouse gases and other air pollutants emissions. Regional emissions levels from road vehicles were investigated, in Mauritius, by applying a fuel-based approach. We estimated fuel consumption and air emissions based on traffic counts on the various types of classified roads at three...

Principal Component Analysis (PCA) is one of the most popular dimensionality-reduction techniques used for the purpose of classification. It has gained popularity because of its ease of use and optimal nature in a mean square error sense. This paper focuses on an analysis of PCA as a classification tool for rainfall images. Rainfall maps were gener...

In this digital era, high-resolution imagery offers a rapid and inexpensive means of monitoring land use changes. Digitally monitoring dynamic landscape change is a versatile way of facilitating rapid strategic decision making in a sustainable manner in a world of increasing complexity. Whilst a cadastral land information system is useful as a data...

The Erosivity Index (EI) and the Modified Fournier Index (MFI) are two commonly used methods in calculating the R factor of the universal soil loss equation/revised universal soil loss equation formula. Using Mauritius as a case study, the value of high-resolution data versus long-term totals in erosivity calculations is investigated. A limited num...

Emissions modeling provides a basis for reducing greenhouse gases, improving air quality, and planning for healthy development

In this paper, we compare the performances of three iterative solvers for large sparse linear systems arising in the numerical computations of incompressible Navier-Stokes (NS) equations. These equations are employed mainly in the simulation of microwave heating of liquids. The emphasis of this work is on the application of Krylov projection techni...

Mauritius is a typical tropical volcanic island with a distinct elevated central plateau above 550 m.a.s.l. Rainfall depth, duration, intensity, kinetic energy, and erosivity were analysed for 385 erosive rainfall events at five locations over a five-year period (2004 to 2008). Two Mauritius Meteorological Services stations located on the west coas...

An E-Portfolio is a digital collection of works, artifacts, resources, including demonstrations, projects, art works in form of graphics (2D, 3D), accomplishments that represent a student’s work. The concept of e-portfolio has been derived from the traditional portfolios. From a pedagogical viewpoint, the portfolio was meant to improve the assessm...

We study skew-Hermitian based splitting methods for the iterative solution of nonsymmetric linear systems arising from high-order compact (HOC) approximations of two-dimensional convection–diffusion problems. Such discretisations lead to nine-point system matrices with block-tridiagonal structures. The nonsymmetric discretisation matrix for a const...

In numerical option pricing, spatial discretization of the pricing equation leads to semi-discrete systems of the form $${V}^{\prime}\left( \tau \right)=AV\left( \tau \right)+b\left( \tau \right),$$ (4.1) where A ∊ ℜ m×m is in general a negative semi-definite matrix and b(τ) generally represents boundary condition implementations, a penalty term fo...

We study some properties of block-circulant preconditioners for high-order compact approximations of convection–diffusion problems. For two-dimensional problems, the approximation gives rise to a nine-point discretisation matrix and in three dimensions, we obtain a nineteen-point matrix. We derive analytical expressions for the eigenvalues of the b...

Convergence of the implicitly restarted Arnoldi (IRA) method for nonsymmetric eigenvalue problems has often been studied by deriving bounds for the angle between a desired eigenvector and the Krylov projection subspace. Bounds for residual norms of approximate eigenvectors have been less studied and this paper derives a new a-posteriori residual bo...

We analyze a Simpler GMRES variant of augmented GMRES with implicit restarting for solving nonsymmetric linear systems with small eigenvalues. The use of a shifted Arnoldi process in the Simpler GMRES variant for computing Arnoldi basis vectors has the advantage of not requiring an upper Hessenberg factorization and this often leads to cheaper impl...

This paper enhances the IRA method whereby the computational cost is extremely reduced. A must try algorithm that have many applications. For more information the first author may be contacted. (Top 25 Download in Science-Direct;http://top25.sciencedirect.com/subject/mathematics/16/journal/mathematics-and-computers-in-simulation/03784754/archive/2...

We present an analysis of a semi-circulant preconditioner for a high-order compact discretization of a two-dimensional convection-diffusion equation with grid-aligned flow. We show that the eigenvalues of the preconditioned matrix lie in two intervals on the left and right side of unity.

The disposal of nonhazardous solid waste on the island of Mauritius is centered on the Mare Chicose landfill. Because of health concerns in the community, the authors conducted a health impact survey, took measurements of height and weight, and compared the results with a control locality. After adjusting for confounding factors, the authors observ...

The numerical valuation of options on an asset with price dynamics following a jump diffusion process requires solving a partial integro-differential equation (PIDE). Crank-Nicolson, second-order backward difference formula (BDF-2), IMEXRK and alternating direction implicit (ADI) timestepping methods have been employed for solving the large systems...

We study the stability of zero-fill incomplete LU factorizations of a nine-point coefficient matrix arising from a high-order compact discretisation of a two-dimensional constant-coefficient convection–diffusion problem. Nonlinear recurrences for computing entries of the lower and upper triangular matrices are derived and we show that the sequence...

In this article, we discuss a recently conducted study that deals with the spatial distribution of emissions to the air. Spatial distribution of emissions has been widely studied using different approaches, notably: • Physical—providing scaled-down representations of reality, and • Mathematical—describing spatial distributions using mathematical re...

We consider the iterative solution of cyclically-reduced linear systems arising from central-difference approximations of three-dimensional convection diffusion problems using deflated GMRES algorithms. Experimental results show that deflated variants of GMRES are more efficient than restarted GMRES and Simpler GMRES for both full and reduced syste...

We examine the performance of sparse approximate inverse smoothers for the multigrid solution of high-order compact approximations to convection-diffusion problems. A local least squares approximation and a hierarchy of smoothers constructed using the sparse parallel approximate inverse (SPAI) algorithm are studied. Numerical results are described...

We describe a method for improving the convergence of the Simpler GMRES method for problems with small eigenvalues. We augment the Krylov subspace with harmonic Ritz vectors corresponding to the smallest harmonic Ritz values. The advantage over augmented GMRES is that the problem of finding the minimal residual solution reduces to an upper triangul...

We describe an augmented version of Simpler GMRES (SGMRES) for problems with small eigenvalues. The advantage is that the SGMRES variant requires a lesser amount of work than augmented GMRES. We show that the problem of finding harmonic Ritz vectors for augmenting the Krylov subspace can be easily reduced to an eigenvalue problem by computing recur...

We describe a method for improving the convergence of the simpler generalized minimal residual GMRES method for problems with small eigenvalues. We augment the Krylov subspace with harmonic Ritz vectors corresponding to the smallest harmonic Ritz values. The advantage over the augmented GMRES is that the problem of finding the minimal residual solu...

We consider hybrid and adaptive iterative algorithms for cyclically-reduced discrete convection-diffusion problems. Hybrid algorithms combine via a two phase algorithm, iterative methods which require no a priori information about the coefficient matrix in the first phase with Chebyshev or Richardson iteration in the second phase. For two-dimension...