We present a spectral approach to design approximation algorithms for network problems. observe that the underlying mathematical questions are rounding problems, which were studied in sparsification and discrepancy theory. extend these results incorporate additional non-negative linear constraints, show they can be used significantly scope of problems solved. Our algorithm is an iterative rando...

In this research, Artificial Neural Networks (ANNs) have been used as a powerful tool to solve the inverse kinematic equations of a parallel robot. For this purpose, we have developed the kinematic equations of a Tricept parallel kinematic mechanism with two rotational and one translational degrees of freedom (DoF). Using the analytical method, the inverse kinematic equations are solved for spe...

The aim of this study is to propose a comprehensive approach for handling the crew scheduling problem in the railway systems. In this approach, the information of different railway trips are considered as input and the problem is divided to three separated phases. In phase I, we generate all feasible sequences of the trips, which are named as the pairings. A depth-first search algorithm is deve...

One policy making issue that needs to be addressed more effectively through an intergovernmental and participatory approach is entrepreneurship policy. Entrepreneurship is an area where interdependencies are very high, and the establishment of collaborative relationships such as networks is vital. Therefore, a network approach in the entrepreneurial policy-making process, which leads to the inv...

many studies have been conducted to determine the efficiency of two-stage network structures in the recent years. the two-stage network with additional inputs to the second stage, in which the second stage is independent of the first stage are one of these structures. thus, there is a need for a model capable of calculating the efficiency of two-stage structures as well as efficiency of each st...

There are two dominant approaches to describe and understand the anatomy of complete health and well-being systems internationally. Yet, neither approach has been able to either predict or explain occasional but dramatic crises in health and well-being systems around the world and in developed emerging market or developing country contexts. As the impacts of such events can be measured not simp...