BACKGROUND Due to the different properties of the contrast agents, the lung perfusion maps as measured by 99mTc-labeled macroaggregated albumin perfusion scintigraphy (PS) are not uncommonly discrepant from those measured by dynamic contrast-enhanced MRI (DCE-MRI) using indicator-dilution analysis in complex pulmonary circulation. Since PS offers the pre-capillary perfusion of the first-pass tr...

This paper investigates whether the gravity model (GM) can explain the statistical properties of the International Trade Network (ITN). We fit data on international-trade flows with a GM specification using alternative fitting techniques and we employ GM estimates to build a weighted predicted ITN, whose topological properties are compared to observed ones. Furthermore, we propose an estimation...

Flow shop problems as a typical manufacturing challenge have gained wide attention in academic fields. In this paper, we consider a bi-criteria permutation flow shop scheduling problem, where weighted mean completion time and weighted mean tardiness are to be minimized simultaneously. Since a flow shop scheduling problem has been proved to be NP-hard in strong sense, an effective multi-objectiv...

In the present work, an industrial case study has been considered for multi-objective flow shop scheduling problem including the sequence dependent set up time. The multi-objectives include the minimization of sum of total weighted squared tardiness, total weighted squared earliness, makespan and number of tardy jobs. Industries can select the optimal sequence with respect to required objective...

This paper presents a new mixed-integer goal programming (MIGP) model for a parallel machine scheduling problem with sequence-dependent setup times and release dates under the hypothesis of fuzzy processing time’s knowledge. Two objectives are considered in the model to minimize the total weighted flow time and the total weighted tardiness simultaneously. At the end, the effectiveness of the pr...

We present an approach for analysing weighted networks based on maximum flows between nodes and generalize to weighted networks ‘global’ measures that are well-established for binary networks, such as pathlengths, component size or betweenness centrality. This leads to a generalization of the algorithm of Girvan and Newman for community identification. The application of the weighted network me...

PURPOSE To characterize the MR appearance of the common hemangioma of infancy as well as low- and high-flow vascular malformations of the head and neck. PATIENTS AND METHODS Twenty patients with vascular lesions of the head and neck proved either by pathology, angiography, and/or unequivocal clinical diagnosis were included. Vascular lesions included 15 low-flow lesions (four hemangiomas, 10 ...

We consider a stochastic online scheduling environment, where jobs with stochastic processing requirements arrive over time and the objective is to minimize the total weighted completion time. We show that any nondelay algorithm is asymptotically optimal for the stochastic online single machine, flow shop and uniform parallel machine problems under some mild assumptions.

In this paper, we study a set of combinatorial optimization problems on weighted graphs: the shortest path problem with negative weights, the weighted perfect bipartite matching problem, the unit-capacity minimum-cost maximum flow problem and the weighted perfect bipartite b-matching problem under the assumption that kbk1 = O(m). We show that each one of these four problems can be solved in ̃ O(...