4,513,416 research outputs found
Model migration neural network for predicting battery aging trajectories
Accurate prediction of batteries’ future degradation is a key solution to relief users’ anxiety on battery lifespan and electric vehicle’s driving range. Technical challenges arise from the highly nonlinear dynamics of battery aging. In this paper, a feed-forward migration neural network is proposed to predict the batteries’ aging trajectories. Specifically, a base model that describes the capacity decay over time is first established from the existed battery aging dataset. This base model is then transformed by an input-output slope-and-bias-correction (SBC) method structure to capture the degradation of target cell. To enhance the model’s nonlinear transfer capability, the SBC-model is further integrated into a four-layer neural network, and easily trained via the gradient correlation algorithm. The proposed migration neural network is experimentally verified with four different commercial batteries. The predicted RMSEs are all lower than 2.5% when using only the first 30% of aging trajectories for neural network training. In addition, illustrative results demonstrate that a small size feed-forward neural network (down to 1-5-5-1) is sufficient for battery aging trajectory prediction
Network Model Selection for Task-Focused Attributed Network Inference
Networks are models representing relationships between entities. Often these
relationships are explicitly given, or we must learn a representation which
generalizes and predicts observed behavior in underlying individual data (e.g.
attributes or labels). Whether given or inferred, choosing the best
representation affects subsequent tasks and questions on the network. This work
focuses on model selection to evaluate network representations from data,
focusing on fundamental predictive tasks on networks. We present a modular
methodology using general, interpretable network models, task neighborhood
functions found across domains, and several criteria for robust model
selection. We demonstrate our methodology on three online user activity
datasets and show that network model selection for the appropriate network task
vs. an alternate task increases performance by an order of magnitude in our
experiments
Network model of human language
The phenomenon of human language is widely studied from various points of
view. It is interesting not only for social scientists, antropologists or
philosophers, but also for those, interesting in the network dynamics. In
several recent papers word web, or language as a graph has been investigated.
In this paper I revise recent studies of syntactical word web. I present a
model of growing network in which such processes as node addition, edge
rewiring and new link creation are taken into account. I argue, that this model
is a satisfactory minimal model explaining measured data.Comment: 10 pages, 1 fig, to appear in Physica
Multilayer weighted social network model
Recent empirical studies using large-scale data sets have validated the
Granovetter hypothesis on the structure of the society in that there are
strongly wired communities connected by weak ties. However, as interaction
between individuals takes place in diverse contexts, these communities turn out
to be overlapping. This implies that the society has a multilayered structure,
where the layers represent the different contexts. To model this structure we
begin with a single-layer weighted social network (WSN) model showing the
Granovetterian structure. We find that when merging such WSN models, a
sufficient amount of interlayer correlation is needed to maintain the
relationship between topology and link weights, while these correlations
destroy the enhancement in the community overlap due to multiple layers. To
resolve this, we devise a geographic multilayer WSN model, where the indirect
interlayer correlations due to the geographic constraints of individuals
enhance the overlaps between the communities and, at the same time, the
Granovetterian structure is preserved.Comment: 9 pages, 9 figure
Evolving Social Networks via Friend Recommendations
A social network grows over a period of time with the formation of new
connections and relations. In recent years we have witnessed a massive growth
of online social networks like Facebook, Twitter etc. So it has become a
problem of extreme importance to know the destiny of these networks. Thus
predicting the evolution of a social network is a question of extreme
importance. A good model for evolution of a social network can help in
understanding the properties responsible for the changes occurring in a network
structure. In this paper we propose such a model for evolution of social
networks. We model the social network as an undirected graph where nodes
represent people and edges represent the friendship between them. We define the
evolution process as a set of rules which resembles very closely to how a
social network grows in real life. We simulate the evolution process and show,
how starting from an initial network, a network evolves using this model. We
also discuss how our model can be used to model various complex social networks
other than online social networks like political networks, various
organizations etc..Comment: 5 pages, 8 figures, 2 algorithm
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