Search results for "Graph theory"
showing 10 items of 784 documents
Spurious finite-size instabilities in nuclear energy density functionals
2013
It is known that some well-established parametrizations of the EDF do not always provide converged results for nuclei and a qualitative link between this finding and the appearance of finite-size instabilities of SNM near saturation density when computed within the RPA has been pointed out. We seek for a quantitative and systematic connection between the impossibility to converge self-consistent calculations of nuclei and the occurrence of finite-size instabilities in SNM for the example of scalar-isovector (S=0, T=1) instabilities of the standard Skyrme EDF. We aim to establish a stability criterion based on computationally-friendly RPA calculations of SNM that is independent on the functi…
Critical path analysis in the network with fuzzy activity times
2001
A natural generalization of the criticality notion in a network with fuzzy activity times is given. It consists in direct application of the extension principle of Zadeh to the notion of criticality of a path (an activity, an event) treated as a function of the activities duration times in the network. There are shown some relations between the notion of fuzzy criticality, introduced in the paper, and the notion of interval criticality (criticality in the network with interval activity times) proposed by the authors in another paper. Two methods of calculation of the path degree of criticality (according to the proposed concept of fuzzy criticality) are presented.
Definition of a Model-Based Detector of Curvilinear Regions
2007
This paper describes a new approach for detection of curvilinear regions. These features detection can be useful for any matching based algorithm such as stereoscopic vision. Our detector is based on curvilinear structure model, defined observing the real world. Then, we propose a multi-scale search algorithm of curvilinear regions and we report some preliminary results.
EFFECTS OF CUSTOMER KNOWLEDGE MANAGEMENT AND CUSTOMER ORIENTATION ON INNOVATION CAPACITY AND MARKETING RESULTS IN SMEs: THE MEDIATING ROLE OF INNOVAT…
2018
Managing customer knowledge is a key of source for SMEs. The principal aim of this paper is to provide empirical evidence on the direct effects of two specific strategic resources: customer orientation and customer knowledge management (CKM), on innovation capacity and marketing results in SMEs. The study also examines the role of innovation orientation as a mediator between customer orientation and CKM. For this purpose, a structural model was proposed and tested through an empirical investigation with variance-based structural equation modeling (PLS) using a sample made up of 210 Spanish SMEs. The findings highlight the relevance of CKM and customer orientation as important strategic res…
Dagger closure and solid closure in graded dimension two
2013
We introduce a graded version of dagger closure and prove that it coincides with solid closure for homogeneous ideals in two-dimensional N \mathbb {N} -graded domains of finite type over a field.
New results for finding common neighborhoods in massive graphs in the data stream model
2008
AbstractWe consider the problem of finding pairs of vertices that share large common neighborhoods in massive graphs. We give lower bounds for randomized, two-sided error algorithms that solve this problem in the data-stream model of computation. Our results correct and improve those of Buchsbaum, Giancarlo, and Westbrook [On finding common neighborhoods in massive graphs, Theoretical Computer Science, 299 (1–3) 707–718 (2004)]
An Open Innovation Decision Support System to Select a Biopharmaceutical R&D Portfolio
2015
Drugs available in the market today, selected several years ago under very uncertain future scenario, have experienced a long and expensive process of research and development carried out following both a closed and an open innovation path. To support this critical selection process, we propose a Decision Support System, able to choose among different candidates the most promising drugs along their best development path. The Decision Support System, based on a real options portfolio optimization model, mapping tools, and what-if rules as well, has been applied to a numerical example available in literature, and the research findings show interesting managerial and academic implications. Cop…
Adaptive rational interpolation for cell-average
2020
Abstract In this paper, we extend the rational interpolation introduced by G. Ramponi et al. (1997, 1998, 1996, 1995) to the cell average setting. We propose a new family of non linear interpolation operator. It consists on constructing new approximations using a non linear weighted combination of polynomials of degree 1 or 2 to obtain new interpolations of degree 2 or 4 respectively. New weights are proposed and analyzed. Gibbs phenomenon is studied and some experiments are performed comparing the new methods with classical linear and non linear interpolation as Weighted Essentially Non-Oscillatory (WENO).
Using partial-orders for detecting faults in concurrent systems
1998
The paper suggests test derivation approaches to obtain test suites for concurrent systems based on the concept of fault coverage criteria in opposition to structural test coverage criteria. Using a partial-order model, called Mazurkiewicz Trace Machine (MTM), for test derivation, the state explosion problem can be alleviated. The derived test suites are characterized by their small size compared to test suites from traditional test derivation approaches and exhibit a defined degree of fault coverage according to certain fault models. The fault models of concurrent systems considered in the paper are based on the most common faults, acceptance, refusal, and transfer faults. A scenario of te…
Bounds for the relative n-th nilpotency degree in compact groups
2009
The line of investigation of the present paper goes back to a classical work of W. H. Gustafson of the 1973, in which it is described the probability that two randomly chosen group elements commute. In the same work, he gave some bounds for this kind of probability, providing information on the group structure. We have recently obtained some generalizations of his results for finite groups. Here we improve them in the context of the compact groups.