Person: Gómez González, Daniel
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First Name
Daniel
Last Name
Gómez González
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Estudios estadísticos
Department
Estadística y Ciencia de los Datos
Area
Estadística e Investigación Operativa
Identifiers
6 results
Search Results
Now showing 1 - 6 of 6
Item Allocating slacks in stochastic PERT network(Central European journal of operations research, 2014) Castro Cantalejo, Javier; Gómez González, Daniel; Tejada Cazorla, Juan AntonioThe SPERT problem was defined, in a game theory framework, as the fair allocation of the slack or float among the activities in a PERT network previous to the execution of the project. Previous approaches tackle with this problem imposing that the durations of the activities are deterministic. In this paper, we extend the SPERT problem into a stochastic framework defining a new solution that tries also to maintain the good performance of some other approaches that have been defined for the deterministic case. Afterward, we present a polynomial algorithm for this new solution that also could be used for the calculation of other approaches founded in the deterministic SPERT literature.Item A new edge betweenness measure using a game theoretical approach: an application to hierarchical community cetection(Mathematics, 2021) Espínola Vílchez, María Rosario; Gómez González, Daniel; Castro Cantalejo, Javier; Gutiérrez García-Pardo, Inmaculada; Jiménez-Losada, Andrés; Goubko, MikhailIn this paper we formally define the hierarchical clustering network problem (HCNP) as the problem to find a good hierarchical partition of a network. This new problem focuses on the dynamic process of the clustering rather than on the final picture of the clustering process. To address it, we introduce a new hierarchical clustering algorithm in networks, based on a new shortest path betweenness measure. To calculate it, the communication between each pair of nodes is weighed by the importance of the nodes that establish this communication. The weights or importance associated to each pair of nodes are calculated as the Shapley value of a game, named as the linear modularity game. This new measure, (the node-game shortest path betweenness measure), is used to obtain a hierarchical partition of the network by eliminating the link with the highest value. To evaluate the performance of our algorithm, we introduce several criteria that allow us to compare different dendrograms of a network from two point of view: modularity and homogeneity. Finally, we propose a faster algorithm based on a simplification of the node-game shortest path betweenness measure, whose order is quadratic on sparse networks. This fast version is competitive from a computational point of view with other hierarchical fast algorithms, and, in general, it provides better results.Item New Aggregation Approaches with HSV to Color Edge Detection(International Journal of Computational Intelligence Systems, 2022) Flores Vidal, Pablo Arcadio; Gómez González, Daniel; Castro Cantalejo, Javier; Montero, JavierThe majority of edge detection algorithms only deal with grayscale images, while their use with color images remains an open problem. This paper explores different approaches to aggregate color information of RGB and HSV images for edge extraction purposes through the usage of the Sobel operator and Canny algorithm. This paper makes use of Berkeley’s image data set, and to evaluate the performance of the different aggregations, the F-measure is computed. Higher potential of aggregations with HSV channels than with RGB channels is found. This article also shows that depending on the type of image used, RGB or HSV, some methods are more appropriate than others.Item A project game for PERT networks(Operations Research Letters, 2007) Castro Cantalejo, Javier; Gómez González, Daniel; Tejada Cazorla, Juan AntonioAn important topic in PERT networks is how to allocate the total expedition (or delay) for situations in which the project is not executed as planned. In order to do that we define a TU project game that satisfies some desirable properties from the management project and game theory point of view.Item A rule for slack allocation proportional to the duration in a PERT network(European journal of operational research, 2008) Castro Cantalejo, Javier; Gómez González, Daniel; Tejada Cazorla, Juan AntonioIn this paper, we define a new rule for the resolution of the slack allocation problem in a PERT network. This problem exists of allocating existing extra time in some paths among the activities belonging to those paths. The allocation rule that we propose assigns extra time to the activities proportionally to their durations in such a way that no path duration exceeds the completion time of the whole project. This time allocation enables us to make a schedule for the PERT project under study. We give two characterizations of the rule and we compare it with others that have been previously defined in the literature.Item A polynomial rule for the problem of sharing delay costs in PERT networks(Computers and Operations Research, 2008) Castro Cantalejo, Javier; Gómez González, Daniel; Tejada Cazorla, Juan AntonioIn this paper we define the weighted serial cost sharing rule for the cost allocation problem.We apply this new rule to the problem of sharing delay costs in a PERT network. This rule belongs to the Core and is the Weighted Shapley Value for a particular game. Furthermore, we present a characterization of this rule and a polynomial algorithm for its calculation.