38 research outputs found
One-Class Classification: Taxonomy of Study and Review of Techniques
One-class classification (OCC) algorithms aim to build classification models
when the negative class is either absent, poorly sampled or not well defined.
This unique situation constrains the learning of efficient classifiers by
defining class boundary just with the knowledge of positive class. The OCC
problem has been considered and applied under many research themes, such as
outlier/novelty detection and concept learning. In this paper we present a
unified view of the general problem of OCC by presenting a taxonomy of study
for OCC problems, which is based on the availability of training data,
algorithms used and the application domains applied. We further delve into each
of the categories of the proposed taxonomy and present a comprehensive
literature review of the OCC algorithms, techniques and methodologies with a
focus on their significance, limitations and applications. We conclude our
paper by discussing some open research problems in the field of OCC and present
our vision for future research.Comment: 24 pages + 11 pages of references, 8 figure
FedSL: Federated Split Learning on Distributed Sequential Data in Recurrent Neural Networks
Federated Learning (FL) and Split Learning (SL) are privacy-preserving
Machine-Learning (ML) techniques that enable training ML models over data
distributed among clients without requiring direct access to their raw data.
Existing FL and SL approaches work on horizontally or vertically partitioned
data and cannot handle sequentially partitioned data where segments of
multiple-segment sequential data are distributed across clients. In this paper,
we propose a novel federated split learning framework, FedSL, to train models
on distributed sequential data. The most common ML models to train on
sequential data are Recurrent Neural Networks (RNNs). Since the proposed
framework is privacy preserving, segments of multiple-segment sequential data
cannot be shared between clients or between clients and server. To circumvent
this limitation, we propose a novel SL approach tailored for RNNs. A RNN is
split into sub-networks, and each sub-network is trained on one client
containing single segments of multiple-segment training sequences. During local
training, the sub-networks on different clients communicate with each other to
capture latent dependencies between consecutive segments of multiple-segment
sequential data on different clients, but without sharing raw data or complete
model parameters. After training local sub-networks with local sequential data
segments, all clients send their sub-networks to a federated server where
sub-networks are aggregated to generate a global model. The experimental
results on simulated and real-world datasets demonstrate that the proposed
method successfully train models on distributed sequential data, while
preserving privacy, and outperforms previous FL and centralized learning
approaches in terms of achieving higher accuracy in fewer communication rounds