9,471 research outputs found
Forecasting the Missing Links in Heterogeneous Social Networks
Social network analysis has gained attention from several researchers in the past time because of its wide application in capturing social interactions. One of the aims of social network analysis is to recover missing links between the users which may exist in the future but have not yet appeared due to incomplete data. The prediction of hidden or missing links in criminal networks is also a significant problem. The collection of criminal data from these networks appears to be incomplete and inconsistent which is reflected in the structure in the form of missing nodes and links. Many machine learning algorithms are applied for this detection using supervised techniques. But, supervised machine learning algorithms require large datasets for training the link prediction model for achieving optimum results. In this research, we have used a Facebook dataset to solve the problem of link prediction in a network. The two machine learning classifiers applied are LogisticRegression and K-Nearest Neighbour where KNN has higher accuracy than LR. In this article, we have proposed an algorithm Graph Sample Aggregator with Low Reciprocity, (GraphSALR), for the generation of node embeddings in larger graphs which use node feature information
Machine learning partners in criminal networks
Recent research has shown that criminal networks have complex organizational structures, but whether this can be used to predict static and dynamic properties of criminal networks remains little explored. Here, by combining graph representation learning and machine learning methods, we show that structural properties of political corruption, police intelligence, and money laundering networks can be used to recover missing criminal partnerships, distinguish among diferent types of criminal and legal associations, as well as predict the total amount of money exchanged among criminal agents, all with outstanding accuracy. We also show that our approach can anticipate future criminal associations during the dynamic growth of corruption networks with signifcant accuracy. Thus, similar to evidence found at crime scenes, we conclude that structural patterns of criminal networks carry crucial information about illegal activities, which allows machine learning methods to predict missing information and even anticipate future criminal behavior
State of the art 2015: a literature review of social media intelligence capabilities for counter-terrorism
Overview
This paper is a review of how information and insight can be drawn from open social media sources. It focuses on the specific research techniques that have emerged, the capabilities they provide, the possible insights they offer, and the ethical and legal questions they raise. These techniques are considered relevant and valuable in so far as they can help to maintain public safety by preventing terrorism, preparing for it, protecting the public from it and pursuing its perpetrators. The report also considers how far this can be achieved against the backdrop of radically changing technology and public attitudes towards surveillance. This is an updated version of a 2013 report paper on the same subject, State of the Art. Since 2013, there have been significant changes in social media, how it is used by terrorist groups, and the methods being developed to make sense of it.
The paper is structured as follows:
Part 1 is an overview of social media use, focused on how it is used by groups of interest to those involved in counter-terrorism. This includes new sections on trends of social media platforms; and a new section on Islamic State (IS).
Part 2 provides an introduction to the key approaches of social media intelligence (henceforth âSOCMINTâ) for counter-terrorism.
Part 3 sets out a series of SOCMINT techniques. For each technique a series of capabilities and insights are considered, the validity and reliability of the method is considered, and how they might be applied to counter-terrorism work explored.
Part 4 outlines a number of important legal, ethical and practical considerations when undertaking SOCMINT work
Reconstructing Sparse Illicit Supply Networks: A Case Study of Multiplex Drug Trafficking Networks
The network structure provides critical information for law enforcement
agencies to develop effective strategies to interdict illicit supply networks.
However, the complete structure of covert networks is often unavailable, thus
it is crucially important to develop approaches to infer a more complete
structure of covert networks. In this paper, we work on real-world multiplex
drug trafficking networks extracted from an investigation report. A statistical
approach built on the EM algorithm (DegEM) as well as other methods based on
structural similarity are applied to reconstruct the multiplex drug trafficking
network given different fractions of observed nodes and links. It is found that
DegEM approach achieves the best predictive performance in terms of several
accuracy metrics. Meanwhile, structural similarity-based methods perform poorly
in reconstructing the drug trafficking networks due to the sparsity of links
between nodes in the network. The inferred multiplex networks can be leveraged
to (i) inform the decision-making on monitoring covert networks as well as
allocating limited resources for collecting additional information to improve
the reconstruction accuracy and (ii) develop more effective interdiction
strategies
Progresses and Challenges in Link Prediction
Link prediction is a paradigmatic problem in network science, which aims at
estimating the existence likelihoods of nonobserved links, based on known
topology. After a brief introduction of the standard problem and metrics of
link prediction, this Perspective will summarize representative progresses
about local similarity indices, link predictability, network embedding, matrix
completion, ensemble learning and others, mainly extracted from thousands of
related publications in the last decade. Finally, this Perspective will outline
some long-standing challenges for future studies.Comment: 45 pages, 1 tabl
A parameterised model for link prediction using node centrality and similarity measure based on graph embedding
Link prediction is a key aspect of graph machine learning, with applications
as diverse as disease prediction, social network recommendations, and drug
discovery. It involves predicting new links that may form between network
nodes. Despite the clear importance of link prediction, existing models have
significant shortcomings. Graph Convolutional Networks, for instance, have been
proven to be highly efficient for link prediction on a variety of datasets.
However, they encounter severe limitations when applied to short-path networks
and ego networks, resulting in poor performance. This presents a critical
problem space that this work aims to address. In this paper, we present the
Node Centrality and Similarity Based Parameterised Model (NCSM), a novel method
for link prediction tasks. NCSM uniquely integrates node centrality and
similarity measures as edge features in a customised Graph Neural Network (GNN)
layer, effectively leveraging the topological information of large networks.
This model represents the first parameterised GNN-based link prediction model
that considers topological information. The proposed model was evaluated on
five benchmark graph datasets, each comprising thousands of nodes and edges.
Experimental results highlight NCSM's superiority over existing
state-of-the-art models like Graph Convolutional Networks and Variational Graph
Autoencoder, as it outperforms them across various metrics and datasets. This
exceptional performance can be attributed to NCSM's innovative integration of
node centrality, similarity measures, and its efficient use of topological
information
Object-oriented Neural Programming (OONP) for Document Understanding
We propose Object-oriented Neural Programming (OONP), a framework for
semantically parsing documents in specific domains. Basically, OONP reads a
document and parses it into a predesigned object-oriented data structure
(referred to as ontology in this paper) that reflects the domain-specific
semantics of the document. An OONP parser models semantic parsing as a decision
process: a neural net-based Reader sequentially goes through the document, and
during the process it builds and updates an intermediate ontology to summarize
its partial understanding of the text it covers. OONP supports a rich family of
operations (both symbolic and differentiable) for composing the ontology, and a
big variety of forms (both symbolic and differentiable) for representing the
state and the document. An OONP parser can be trained with supervision of
different forms and strength, including supervised learning (SL) ,
reinforcement learning (RL) and hybrid of the two. Our experiments on both
synthetic and real-world document parsing tasks have shown that OONP can learn
to handle fairly complicated ontology with training data of modest sizes.Comment: accepted by ACL 201
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