Fahimeh Ramezani

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The authors use ideas from graph theory in order to determine how distant is a given biological network from being monotone. On the signed graph representing the system, the minimal number of sign inconsistencies (i.e. the distance to monotonicity) is shown to be equal to the minimal number of fundamental cycles having a negative sign. Suitable operations(More)
Live virtual machine (VM) migration is a technique for achieving system load balancing in a cloud environment by transferring an active VM from one physical host to another. This technique has been proposed to reduce the downtime for migrating overloaded VMs, but it is still time- and cost-consuming, and a large amount of memory is involved in the migration(More)
R. Lavi and C. Swamy (FOCS 2005, J. ACM 58(6), 25, 2011) introduced a general method for obtaining truthful-in-expectation mechanisms from linear programming based approximation algorithms. Due to the use of the Ellipsoid method, a direct implementation of the method is unlikely to be efficient in practice. We propose to use the much simpler and usually(More)
MOTIVATION Given a large-scale biological network represented as an influence graph, in this article we investigate possible decompositions of the network aimed at highlighting specific dynamical properties. RESULTS The first decomposition we study consists in finding a maximal directed acyclic subgraph of the network, which dynamically corresponds to(More)
Given two bounded convex sets $$X\subseteq \mathbb R^m$$ X ⊆ R m and $$Y\subseteq \mathbb R^n,$$ Y ⊆ R n , specified by membership oracles, and a continuous convex–concave function $$F:X\times Y\rightarrow \mathbb R$$ F : X × Y → R , we consider the problem of computing an $$\varepsilon $$ ε -approximate saddle point, that is, a pair $$(x^*,y^*)\in X\times(More)
Optimizing task scheduling in a distributed heterogeneous computing environment, which is a nonlinear multi-objective NP-hard problem, plays a critical role in decreasing service response time and cost, and boosting Quality of Service (QoS). This paper, considers four conflicting objectives, namely minimizing task transfer time, task execution cost, power(More)
In recent years a new concept of IT organization emerged, the Cloud Computing. With This new concept, the resources are dynamically scalable, virtualized and provided to users as a service on the Internet. It is primarily intended to meet the demands of users and allow them access to virtually unlimited resources. This model motivates many academic(More)