6,704 research outputs found
Holistic Influence Maximization: Combining Scalability and Efficiency with Opinion-Aware Models
The steady growth of graph data from social networks has resulted in
wide-spread research in finding solutions to the influence maximization
problem. In this paper, we propose a holistic solution to the influence
maximization (IM) problem. (1) We introduce an opinion-cum-interaction (OI)
model that closely mirrors the real-world scenarios. Under the OI model, we
introduce a novel problem of Maximizing the Effective Opinion (MEO) of
influenced users. We prove that the MEO problem is NP-hard and cannot be
approximated within a constant ratio unless P=NP. (2) We propose a heuristic
algorithm OSIM to efficiently solve the MEO problem. To better explain the OSIM
heuristic, we first introduce EaSyIM - the opinion-oblivious version of OSIM, a
scalable algorithm capable of running within practical compute times on
commodity hardware. In addition to serving as a fundamental building block for
OSIM, EaSyIM is capable of addressing the scalability aspect - memory
consumption and running time, of the IM problem as well.
Empirically, our algorithms are capable of maintaining the deviation in the
spread always within 5% of the best known methods in the literature. In
addition, our experiments show that both OSIM and EaSyIM are effective,
efficient, scalable and significantly enhance the ability to analyze real
datasets.Comment: ACM SIGMOD Conference 2016, 18 pages, 29 figure
Trends Prediction Using Social Diffusion Models
The importance of the ability of predict trends in social media has been
growing rapidly in the past few years with the growing dominance of social
media in our everyday's life. Whereas many works focus on the detection of
anomalies in networks, there exist little theoretical work on the prediction of
the likelihood of anomalous network pattern to globally spread and become
"trends". In this work we present an analytic model the social diffusion
dynamics of spreading network patterns. Our proposed method is based on
information diffusion models, and is capable of predicting future trends based
on the analysis of past social interactions between the community's members. We
present an analytic lower bound for the probability that emerging trends would
successful spread through the network. We demonstrate our model using two
comprehensive social datasets - the "Friends and Family" experiment that was
held in MIT for over a year, where the complete activity of 140 users was
analyzed, and a financial dataset containing the complete activities of over
1.5 million members of the "eToro" social trading community.Comment: 6 Pages + Appendi
NetLSD: Hearing the Shape of a Graph
Comparison among graphs is ubiquitous in graph analytics. However, it is a
hard task in terms of the expressiveness of the employed similarity measure and
the efficiency of its computation. Ideally, graph comparison should be
invariant to the order of nodes and the sizes of compared graphs, adaptive to
the scale of graph patterns, and scalable. Unfortunately, these properties have
not been addressed together. Graph comparisons still rely on direct approaches,
graph kernels, or representation-based methods, which are all inefficient and
impractical for large graph collections.
In this paper, we propose the Network Laplacian Spectral Descriptor (NetLSD):
the first, to our knowledge, permutation- and size-invariant, scale-adaptive,
and efficiently computable graph representation method that allows for
straightforward comparisons of large graphs. NetLSD extracts a compact
signature that inherits the formal properties of the Laplacian spectrum,
specifically its heat or wave kernel; thus, it hears the shape of a graph. Our
evaluation on a variety of real-world graphs demonstrates that it outperforms
previous works in both expressiveness and efficiency.Comment: KDD '18: The 24th ACM SIGKDD International Conference on Knowledge
Discovery & Data Mining, August 19--23, 2018, London, United Kingdo
Brief History of Quantum Cryptography: A Personal Perspective
Quantum cryptography is the only approach to privacy ever proposed that
allows two parties (who do not share a long secret key ahead of time) to
communicate with provably perfect secrecy under the nose of an eavesdropper
endowed with unlimited computational power and whose technology is limited by
nothing but the fundamental laws of nature. This essay provides a personal
historical perspective on the field. For the sake of liveliness, the style is
purposely that of a spontaneous after-dinner speech.Comment: 14 pages, no figure
Quantum cryptography: key distribution and beyond
Uniquely among the sciences, quantum cryptography has driven both
foundational research as well as practical real-life applications. We review
the progress of quantum cryptography in the last decade, covering quantum key
distribution and other applications.Comment: It's a review on quantum cryptography and it is not restricted to QK
MLCapsule: Guarded Offline Deployment of Machine Learning as a Service
With the widespread use of machine learning (ML) techniques, ML as a service
has become increasingly popular. In this setting, an ML model resides on a
server and users can query it with their data via an API. However, if the
user's input is sensitive, sending it to the server is undesirable and
sometimes even legally not possible. Equally, the service provider does not
want to share the model by sending it to the client for protecting its
intellectual property and pay-per-query business model.
In this paper, we propose MLCapsule, a guarded offline deployment of machine
learning as a service. MLCapsule executes the model locally on the user's side
and therefore the data never leaves the client. Meanwhile, MLCapsule offers the
service provider the same level of control and security of its model as the
commonly used server-side execution. In addition, MLCapsule is applicable to
offline applications that require local execution. Beyond protecting against
direct model access, we couple the secure offline deployment with defenses
against advanced attacks on machine learning models such as model stealing,
reverse engineering, and membership inference
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