Collection of waste is an important logistic activity within any city. In this study, a mathematical model is proposed in order to reduce the cost of waste collection. First a mixed-integer nonlinear programming model is provided including a waste collection routing problem, so that, there is a balance between the distance between trashcans, and the similarity of the trashcans in terms of th...

This paper presents a theoretical model that combines employers learning about worker productivity, human capital acquisition, job-assignment and resolution of worker uncertainty regarding disutility of work from a job, to show how widely documented findings on both wage and promotion dynamics and turnover can be captured in a single set-up. Specifically we show how our model can capture result...

majority of models in location literature are based on assumptions such as point demand, absence of competitors, as well as monopoly in location, products, and services. however in real-world applications, these assumptions are not well-matched with reality. in this study, a new mixed integer nonlinear programming model based on weighted goal programming approach is proposed to maximize the cap...

todays, improving the competitiveness of companies and rapidly responding to diverse customers’ demands requires efficient management of the supply chain. integration is one of the effective indices in a supply chain, and vendor managed inventory (vmi) is one of the innovative approaches in this field. in this paper, an integrated model based on a vmi system for deteriorating and ameliorating i...

presence of distributed generation (dg) in electric distribution systems provides an attractive new alternative in capacity expansion planning of these systems. in this paper a new model is developed for solving simultaneous placement of hv/mv substations and dg units as a static planning tool. this model aims to minimize fixed and variable costs of planning. constraints related to dgs, substat...

We introduce the “Automated Structure-based Assignment" problem: Given a reference 3D structure, a protein sequence, and its NMR spectra, automatically interpret the NMR spectra and do backbone resonance assignment. We then propose a solution to solve this problem. The core of the solution is a novel integer linear programming model, which is a general framework for many versions of the structu...

The optimal locating of facilities has large effects on economic benefits, providing satisfactory service and levels of customer satisfaction. One of the new topics discussed in location problems is hub location and hub facilities are subject to unpredictable disruptions. This paper proposes a nonlinear integer model for reliable single allocation hub location problem that considers backup hub,...