Search results for "Graph theory"

On threeconnected graphs with unique Hamiltonian cycle = О трехсвязный графах ...

2013

Geodesic graphs

2013

In the article, written in Russian, geodesic graphs, graphs with unique shortest path between every two vertices, are considered. Geodesic graphs are trees, odd cycles, and nontrivial example, the graph of Petersen. The article is dated 21.11.74.

Motives for reflections. Part two

2013

E. Gringergs archive manuscripts may be found in the Library of the University of Latvia under https://lira.lanet.lv/F/98QNED45E7J5HDUHLY51HV43QNRX97XCQJPHQ9S6L7HX4FABFB-10883?func=find-b&request=E.Grinberga&find_code=TIT&x=32&y=13&filter_code_1=WLN&filter_request_1=&filter_code_2=WYR&filter_request_2=&filter_code_3=WYR&filter_request_3=&filter_code_4=WFM&filter_request_4=

Social network analysis approaches to study crime

2022

Social Network Analysis (SNA) studies groups of individuals and can be applied in a lot of areas such us organizational studies, psychology, economics, information science and criminology. One of the most important results of SNA has been the definition of a set of centrality measures (e.g., degree, closeness, betweenness, or clustering coefficient) which can be used to identify the most influential people with respect to their network of relationships. The main problem with computing centrality metrics on social networks is the typical big size of the data. From the computational point of view, SNA represents social networks as graphs composed of a set of nodes connected by another set of …

Computing temporal sequences associated with dynamic patterns on the C. elegans connectome

2021

AbstractUnderstanding how the structural connectivity of a network constrains the dynamics it is able to support is a very active and open area of research. We simulated the plausible dynamics resulting from the known C. elegans connectome using a recent model and theoretical analysis that computes the dynamics of neurobiological networks by focusing on how local interactions among connected neurons give rise to the global dynamics in an emergent way, independent of the biophysical or molecular details of the cells themselves. We studied the dynamics which resulted from stimulating a chemosensory neuron (ASEL) in a known feeding circuit, both in isolation and embedded in the full connectome…

Analysing gene flow in heterogeneous landscapes: why and how to use genetic graphs?

2019

International audience; In heterogeneous landscapes, when species occupy discrete habitat patches, ecological connectivity is influenced by populations’ topology. Graph-theoretic methods constitute a relevant tool to reveal this topology and better analyse gene flow. Despite growing interest in genetic graphs, a better understanding of when and how to use them is lacking.To fill this gap, we simulated gene flow between 50 populations in different landscape configurations and constructed genetic graphs using various genetic distances and pruning (link selection) methods. We then compared metrics derived from these graphs to analogous metrics describing the topology and connectivity of the di…

Existence and uniqueness results for a nonlinear evolution equation arising in growing cell populations

2014

Abstract The present paper is concerned with a nonlinear initial–boundary value problem derived from a model introduced by Rotenberg (1983) describing the growth of a cell population. Each cell of this population is distinguished by two parameters: its degree of maturity μ and its maturation velocity v . At mitosis, the daughter cells and mother cells are related by a general reproduction rule. We prove existence and uniqueness results in the case where the total cross-section and the boundary conditions are depending on the total density of population. Local and nonlocal reproduction rules are discussed.

A Population-Based Approach to the Resource-Constrained Project Scheduling Problem

2004

We present a population-based approach to the RCPSP. The procedure has two phases. The first phase handles the initial construction of a population of schedules and these are then evolved until high quality solutions are obtained. The evolution of the population is driven by the alternative application of an efficient improving procedure for locally improving the use of resources, and a mechanism for combining schedules that blends scatter search and path relinking characteristics. The objective of the second phase is to explore in depth those vicinities near the high quality schedules. Computational experiments on the standard j120 set, generated using ProGen, show that our algorithm produ…

Connections with Other Population-Based Approaches

2003

Throughout this book, we have established that scatter search (SS) belongs to the family of population-based metaheuristics. This family also includes the well-known evolutionary algorithms and the approach known as path relinking.

Robust Selective Stereo SLAM without Loop Closure and Bundle Adjustment

2013

This paper presents a novel stereo SLAM framework, where a robust loop chain matching scheme for tracking keypoints is combined with an effective frame selection strategy. The proposed approach, referred to as selective SLAM (SSLAM), relies on the observation that the error in the pose estimation propagates from the uncertainty of the three-dimensional points. This is higher for distant points, corresponding to matches with low temporal flow disparity in the images. Comparative results based on the reference KITTI evaluation framework show that SSLAM is effective and can be implemented efficiently, as it does not require any loop closure or bundle adjustment.