32 research outputs found
The Impact of Social Curiosity on Information Spreading on Networks
Most information spreading models consider that all individuals are identical
psychologically. They ignore, for instance, the curiosity level of people,
which may indicate that they can be influenced to seek for information given
their interest. For example, the game Pok\'emon GO spread rapidly because of
the aroused curiosity among users. This paper proposes an information
propagation model considering the curiosity level of each individual, which is
a dynamical parameter that evolves over time. We evaluate the efficiency of our
model in contrast to traditional information propagation models, like SIR or
IC, and perform analysis on different types of artificial and real-world
networks, like Google+, Facebook, and the United States roads map. We present a
mean-field approach that reproduces with a good accuracy the evolution of
macroscopic quantities, such as the density of stiflers, for the system's
behavior with the curiosity. We also obtain an analytical solution of the
mean-field equations that allows to predicts a transition from a phase where
the information remains confined to a small number of users to a phase where it
spreads over a large fraction of the population. The results indicate that the
curiosity increases the information spreading in all networks as compared with
the spreading without curiosity, and that this increase is larger in spatial
networks than in social networks. When the curiosity is taken into account, the
maximum number of informed individuals is reached close to the transition
point. Since curious people are more open to a new product, concepts, and
ideas, this is an important factor to be considered in propagation modeling.
Our results contribute to the understanding of the interplay between diffusion
process and dynamical heterogeneous transmission in social networks.Comment: 8 pages, 5 figure
QT-Routenet: Improved GNN generalization to larger 5G networks by fine-tuning predictions from queueing theory
In order to promote the use of machine learning in 5G, the International
Telecommunication Union (ITU) proposed in 2021 the second edition of the ITU
AI/ML in 5G challenge, with over 1600 participants from 82 countries. This work
details the second place solution overall, which is also the winning solution
of the Graph Neural Networking Challenge 2021. We tackle the problem of
generalization when applying a model to a 5G network that may have longer paths
and larger link capacities than the ones observed in training. To achieve this,
we propose to first extract robust features related to Queueing Theory (QT),
and then fine-tune the analytical baseline prediction using a modification of
the Routenet Graph Neural Network (GNN) model. The proposed solution
generalizes much better than simply using Routenet, and manages to reduce the
analytical baseline's 10.42 mean absolute percent error to 1.45 (1.27 with an
ensemble). This suggests that making small changes to an approximate model that
is known to be robust can be an effective way to improve accuracy without
compromising generalization
Performing edge detection by difference of Gaussians using q-Gaussian kernels
In image processing, edge detection is a valuable tool to perform the
extraction of features from an image. This detection reduces the amount of
information to be processed, since the redundant information (considered less
relevant) can be unconsidered. The technique of edge detection consists of
determining the points of a digital image whose intensity changes sharply. This
changes are due to the discontinuities of the orientation on a surface for
example. A well known method of edge detection is the Difference of Gaussians
(DoG). The method consists of subtracting two Gaussians, where a kernel has a
standard deviation smaller than the previous one. The convolution between the
subtraction of kernels and the input image results in the edge detection of
this image. This paper introduces a method of extracting edges using DoG with
kernels based on the q-Gaussian probability distribution, derived from the
q-statistic proposed by Constantino Tsallis. To demonstrate the method's
potential, we compare the introduced method with the traditional DoG using
Gaussians kernels. The results showed that the proposed method can extract
edges with more accurate details.Comment: 5 pages, 5 figures, IC-MSQUARE 201
Graph construction based on labeled instances for semi-supervised learning
Semi-Supervised Learning (SSL) techniques have become very relevant since they require a small set of labeled data. In this context, graph-based algorithms have gained prominence in the area due to their capacity to exploiting, besides information about data points, the relationships among them. Moreover, data represented in graphs allow the use of collective inference (vertices can affect each other), propagation of labels (autocorrelation among neighbors) and use of neighborhood characteristics of a vertex. An important step in graph-based SSL methods is the conversion of tabular data into a weighted graph. The graph construction has a key role in the quality of the classification in graph-based methods. This paper explores a method for graph construction that uses available labeled data. We provide extensive experiments showing the proposed method has many advantages: good classification accuracy, quadratic time complexity, no sensitivity to the parameter k > 10, sparse graph formation with average degree around 2 and hub formation from the labeled points, which facilitates the propagation of labels.Sao Paulo Research Foundation (FAPESP) (Grant 2011/21880-3 and 2011/22749-8
Influence maximization based on the least influential spreaders
The emergence of social media increases the need for the recognization of social influence mainly motivated by online advertising, political and health campaigns, recommendation systems, epidemiological study, etc. In spreading processes, it is possible to define the most central or influential vertices according to the network topology and dynamic. On the other hand, the least influential spreaders have been disregarded. This paper aims to maximize the mean of information propagation on the network by recognizing the non influential individuals by making them better spreader. Experimental results confirm that selecting 0.5% of least influential spreaders in three social networks (google+, hamsterster and advogato) and rewiring one connection to some important vertex, increase the propagation over the entire network.National Council for Scientific and Technological Development (CNPq) (grant: 140688/2013-7)Sao Paulo Research Foundation (FAPESP) (grant: 2011/21880-3
Abordagem Fuzzy na Taxa de Sobrevivência de Trypoxylon (Trypargilum) lactitarse (Hymenoptera: Crabronidae)Fuzzy Approach in the Survival Rate of Trypoxylon (Trypargilum) lactitarse (Hymenoptera: Crabronidae)
Este trabalho apresenta um sistema baseado em regras fuzzy (SBRF) abordando a interação entre fertilidade, tamanho do ninho e sobrevivência de machos e fêmeas de Trypoxylon lactitarse Saussure. A partir de informações sobre fertilidade e tamanho do ninho, o sistema retorna a taxa de sobrevivência de machos e fêmeas permitindo abordar as implicações de uma razão sexual enviesada a favor de machos, uma razão sexual enviesada a favor de fêmeas, ou uma razão sexual de 1:1.Abstract This paper presents a fuzzy rule-based system (FRBS) addressing the interaction among fertility, size of the nest and survival of Trypoxylon lactitarse Saussure males and females. From information on fertility and nest size, the system returns the survival rate of male and female allowing us to address the implications of a skewed sex ratio in favor of males, a skewed sex ratio in favor of females, or a sex ratio of 1:1
The Impact of Social Curiosity on Information Spreading on Networks
Most information spreading models consider that all individuals are identical psychologically. They ignore, for instance, the curiosity level of people, which may indicate that they can be influenced to seek for information given their interest. For example, the game Pokemon GO spread rapidly because of the aroused curiosity among users. This paper proposes an information propagation model considering the curiosity level of each individual, which is a dynamical parameter that evolves over time. We evaluate the efficiency of our model in contrast to traditional information propagation models, like SIR or IC, and perform analysis on different types of artificial and real-world networks, like Google+, Facebook, and the United States roads map. We present a mean-field approach that reproduces with a good accuracy the evolution of macroscopic quantities, such as the density of stiflers, for the system's behavior with the curiosity. We also obtain an analytical solution of the mean-field equations that allows to predicts a transition from a phase where the information remains confined to a small number of users to a phase where it spreads over a large fraction of the population. The results indicate that the curiosity increases the information spreading in all networks as compared with the spreading without curiosity, and that this increase is larger in spatial networks than in social networks. When the curiosity is taken into account, the maximum number of informed individuals is reached close to the transition point. Since curious people are more open to a new product, concepts, and ideas, this is an important factor to be considered in propagation modeling. Our results contribute to the understanding of the interplay between diffusion process and dynamical heterogeneous transmission in social networks.Instituto de Física de Líquidos y Sistemas Biológico
Link prediction in graph construction for supervised and semi-supervised learning
Many real-world domains are relational in nature since they consist of a set of objects related to each other in complex ways. However, there are also flat data sets and if we want to apply graph-based algorithms, it is necessary to construct a graph from this data. This paper aims to: i) increase the exploration of graph-based algorithms and ii) proposes new techniques for graph construction from flat data. Our proposal focuses on constructing graphs using link prediction measures for predicting the existence of links between entities from an initial graph. Starting from a basic graph structure such as a minimum spanning tree, we apply a link prediction measure to add new edges in the graph. The link prediction measures considered here are based on structural similarity of the graph that improves the graph connectivity. We evaluate our proposal for graph construction in supervised and semi-supervised classification and we confirm the graphs achieve better accuracy.São Paulo Research Foundation (FAPESP) (grants: 2013/12191-5, 2011/21880-3 and 2011/22749-8