What are some domains of application for ML in Computer Networks?
security and privacy
anomaly and intrusion detection
traffic identification
wireless network
channel estimation
cognitive radio
localization
feedback loops
congestion contro.l
fault prediction and repair
optimization problems
network design and resource management
placement of devices
What are the 6 major steps in a typical ML based solution?
data collectoin
data processing
model trraining
test data
test data processing
outcome
e.g. measuring of accuracy…
What types of ML methods are there?
supervised
unsupervised
reinforcement learning
What steps are there in supervised learning?
collect / gather labeled data
split into train and test dataset
determine input features of training dataset (should have enough knowledge so that model can accurately predict output)
determine suitable algorithm such as SVM, decision tree, …
execute algo on training dataset
evaluate accuracy of model by providing test dataset
What types of supervised learning are there?
regression
classification
What types of classifiers are there?
binary
multi class
Whyt types of unsupervised ML are ther?
clustering
k-Means
hierarchical
association
anomaly detection
PCA
How does k-means clustering work?
value k as input
choose k datapoints randomly -> centroids of each group
asign remainig datapoints to nearest centroid
calculate within cluster sum of squares
repreat step 2-4 until minimum within-cluster sum of squares are obtained
What does association ML do?
check for dependency of one data item on another data item
-> maps acordingly…
=> tries to find interesting relations or associations among variables of dataset
=> basically works on if else concept… (e.g. if A then B…)
How are the data relaitons in associate learning?
if else consequences
e.g. if buys cereal also expected to buy milk
-> if cereal then milk
cereal called antecedent
milk called consequent
What metrics are there to measure the associations between data items in associate learning=
support
frequency of antecedent (how often occurs in dataset)
confidence
how often rule has found to be true (how often antecedent and consequent occur together)
lift
strenght of any rule
How is the lift calcualted? What does it mean=
support (A,C) / (support(A) * support (C))
lift = 1 -> probability of occurence of antecedent and consequent independent of each other
lift > 1 -> degree of which to item sets are dependent of each other
lift < 1 -> tells that one item is substitute for other items -> one item has negative effect on another
What are the prequisites for the association algorithm?
dataset with fixed number of items (e.g. a, b, c, d)
What are the steps for association algorithm=?
generating itemsets from set of item
-> itemsets consist of all posisble combinations of antecedents and consequents
-> e.g. a => b, a => c, a => {b,c}, b => a, …
for each itemset calculate the confidence value
if confidence value above threshold -> itemset becomes a rule
How to determine if ML model is good?
different metrics for different ML algos
regression:
RMS deviation
the lower, the better
classificatoin:
accuracy (correct class / all class)
precision (TP / TP + FP) -> how many of positive are actual positive
F1 score (2 TP / 2 TP + FP + FN)
-> optimally, all 1
clustering:
WCSS -> if no other value is smaller… (error based)
the hogher the threshold confidence value, the mroe solid the rule
optimally confidence of 1
What are the goals of network intrusion detection?
detect if flows or packets are malicioöus
based on decision,, perform action
machine learning often used in liuterature for this task
What different NN models are there?
fully connected
convolutional
recurrent
graph
What is the advantage of graph based NN in networks?
networks can be abstracted as graph (routing, …)
=> apply graph based model to this graph abstraction of network…
What is the challenge with traditional ML w.r.t. graphs? Solution=
standard ML methods cannot directly process graphs
-> typically process fixed sized inputs
need method for mapping graphs to those fixed size inputs
solution:
reduce graphs to fixed size matrix
-> messagte propagation between nodes
What are the concepts of message propagation in graph NN?
each node has value
those values are propagated along edges of the graph
nodse used those propagated values to update their initial value
node i -> hidden state vector i
hidden state depends on neighboring nodes
message passing split into message function M, aggregation function A, update function U
How is message passing calculated?
apply f to hidden state until fixpoint is reached
-> apply g to get output
Zuletzt geändertvor 2 Jahren