62,890 research outputs found
Exact Computation of Influence Spread by Binary Decision Diagrams
Evaluating influence spread in social networks is a fundamental procedure to
estimate the word-of-mouth effect in viral marketing. There are enormous
studies about this topic; however, under the standard stochastic cascade
models, the exact computation of influence spread is known to be #P-hard. Thus,
the existing studies have used Monte-Carlo simulation-based approximations to
avoid exact computation.
We propose the first algorithm to compute influence spread exactly under the
independent cascade model. The algorithm first constructs binary decision
diagrams (BDDs) for all possible realizations of influence spread, then
computes influence spread by dynamic programming on the constructed BDDs. To
construct the BDDs efficiently, we designed a new frontier-based search-type
procedure. The constructed BDDs can also be used to solve other
influence-spread related problems, such as random sampling without rejection,
conditional influence spread evaluation, dynamic probability update, and
gradient computation for probability optimization problems.
We conducted computational experiments to evaluate the proposed algorithm.
The algorithm successfully computed influence spread on real-world networks
with a hundred edges in a reasonable time, which is quite impossible by the
naive algorithm. We also conducted an experiment to evaluate the accuracy of
the Monte-Carlo simulation-based approximation by comparing exact influence
spread obtained by the proposed algorithm.Comment: WWW'1
Object-oriented modelling with unified modelling language 2.0 for simple software application based on agile methodology
Unified modelling language (UML) 2.0 introduced in 2002 has been developing
and influencing object-oriented software engineering and has become a standard
and reference for information system analysis and design modelling. There are
many concepts and theories to model the information system or software
application with UML 2.0, which can make ambiguities and inconsistencies for a
novice to learn to how to model the system with UML especially with UML 2.0.
This article will discuss how to model the simple software application by using
some of the diagrams of UML 2.0 and not by using the whole diagrams as
suggested by agile methodology. Agile methodology is considered as convenient
for novices because it can deliver the information technology environment to
the end-user quickly and adaptively with minimal documentation. It also has the
ability to deliver best performance software application according to the
customer's needs. Agile methodology will make simple model with simple
documentation, simple team and simple tools.Comment: 15 pages, 30 figure
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