In this paper, a method for finding an approximate solution of a class of two-dimensional nonlinear Volterra integral equations of the first-kind is proposed. This problem is transformedto a nonlinear two-dimensional Volterra integral equation of the second-kind. The properties ofthe bivariate shifted Legendre functions are presented. The operational matrices of integrationtogether with the produ...

Providing the high availability level for the Instrumentation and Control (I&C) Systems in Nuclear Power Plants (NPP) is highly important. The availability of the critical NPP I&C systems depends on the hardware and software reliability behavior. The high availability of the I&C systems is ensured by the following measures: structural redundancy with choice of the I&C system configurations (two...

this paper presents an operational formulation of the tau method based upon orthogonal polynomials by using a reduced set of matrix operations for the numerical solution of nonlinear multi-order fractional differential equations(fdes). the main characteristic behind the approach using this technique is that it reduces such problems to those of solving a system of non-linear algebraic equations....

one of the problems in the ground-based circular synthetic aperture radar is the dependence of the azimuth resolution to the antenna rotation radius and operational limitation of increasing it. to enhance the image quality in azimuth, model-based image formation through three methods: matched filter, inverse filter and optimum filter is suggested and analyzed. for the purpose of comparison, thr...

Oxalic acid dihydrate as a green, mild and efficient catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives from the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with excellent yields and short reaction time is st...

This paper documents a simulation study undertaken to gain insights into the Vari-Metric multi-echelon repairable inventory optimization method. The method was analyzed in the context of the Coast Guard’s fleet of fixed and rotary wing aircraft, for which operational availability is the key performance metric. Failure rates of parts in this system exhibit variance-to-mean ratios higher than one...

In this article, a numerical method based on  improvement of block-pulse functions (IBPFs) is discussed for solving the system of linear Volterra and Fredholm integral equations. By using IBPFs and their operational matrix of integration, such systems can be reduced to a linear system of algebraic equations. An efficient error estimation and associated theorems for the proposed method are also ...

Introduction: new approaches to process safety When introduced in the 1980s, triple modular redundant (TMR) emergency safety shutdown (ESD) systems established a benchmark for providing high levels of safety integrity while reducing the occurrence of costly nuisance trips. Over the years, these types of systems became known as safety instrumented systems (SIS). By any name, traditional TMR safe...

Spaceborne active radar remote sensing, e.g., radar altimeter (RA) and synthetic aperture radar (SAR) have been playing an important role in the validation of numerical wave models, particularly in open ocean. Most forecast centres also use altimeter data in the wave data assimilation process. In this paper we present validation results based on the newly developed CWAVE_ENV algorithm. SAR wave...