This paper deals with the wavelength assignment problem in WDM all-optical networks. This problem can be abstracted as a multicoloring on a weighted conflict graph. The main focus of this work is to obtain the relationship between the wavelength assignment and the multicoloring problems. We, first, establish a new result regarding multicoloring problem in which we provide a tight bound for any ...

Introduction Compared to most industrialized nations, the American system of primary and secondary education is uniquely decentralized. Federal, state and local authorities have a say in educational policy, with the state and local roles being most influential. As a result, educational goals and practices vary enormously, not only by state and school district, but also by schools within distric...

background: regarding the close and continuous interaction of infertility staff with hopeless infertile couples and in the contrary the atmosphere of happiness especially in obstetric wards make a sense that considering anxiety and depression it would be a difference between these two wards. objective: the objective of this study is the comparison of the rate of depression and anxiety between t...

Staff assignment is of great importance for workflow management systems. In many workflow applications, staff assignment is still performed manually. In this paper, we present a semi-automatic approach intended to reduce the number of manual staff assignment. Our approach applies a machine learning algorithm to the workflow event log to learn various kinds of activities that each actor undertak...

Background:Many problems of combinatorial optimization, which are solvable only in exponential time, are known to be Non-Deterministic Polynomial hard (NP-hard). With the advent of parallel machines, new opportunities have been emerged to develop the effective solutions for NP-hard problems. However, solving these problems in polynomial time needs massive parallel machines and ...