The main idea proposed in this paper is the perturbed shifted Chebyshev Galerkin method for the solutions of delay Fredholm and Volterra integrodifferential equations. The application of the proposed method is also extended to the solutions of integro-differential difference equations. The method is validated using some selected problems from the literature. In all the problems that are considered...

Water’s essential function as drinking water is a significant daily intake. Contamination by microorganisms (bacteria or viruses) on sources and supplies common cause in developing countries like Indonesia. This paper will discuss the of clean their problems countries; quality its relation to public health these what efforts that can be make improve quality. The method used literature review fr...

In this work, the capacitated location-routing problem with simultaneous pickup and delivery (CLRP-SPD) is considered. This problem is a more realistic case of the capacitated location-routing problem (CLRP) and belongs to the reverse logistics of the supply chain. The problem has many real-life applications of which some have been addressed in the literature such as management of liquid petrol...