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Table 1 Summary of Symbols and Notations

From: Effective and scalable methods for graph protection strategies against epidemics on dynamic networks

Notation

Definition and description

GD=(VD,ED)

dynamic network GD with the node set VD and the edge set ED

G t

snapshot of dynamic network GD at time t

k

protection budget, i.e., the number of nodes in graph GD that can be protected

S

set of k nodes selected for protection

N

number of nodes in graph GD

M

number of edges in graph GD

β

infection rate

δ

recovery rate

θ

ratio of surviving nodes in graph GD at the end of epidemics

w(u,v)

edge weight between node u and v

V c

vertex cover of graph Gt

\(V_{c}^{*}\)

minimum vertex cover of graph Gt

\(\mathbb {S}\)

current partial solution, set of selected \(V_{c}^{*}\) nodes of graph Gt

d

size of embedding vector dimension

\(h(\mathbb {S})\)

feature-based representation of \(\mathbb {S}\) in d-dimensional vector

B

batch samples of training

\(\mathbb {M}\)

experience replay memory of n-step fitted Q-Learning

ψ i

set of neural network parameters (weights) of respective embedding variable i

Ψ

collection of neural network’s set of parameters (weights) \(\Psi = \{\psi _{i}\}_{i=1}^{7}\)