6,463 research outputs found
Efficient Asymmetric Co-Tracking using Uncertainty Sampling
Adaptive tracking-by-detection approaches are popular for tracking arbitrary
objects. They treat the tracking problem as a classification task and use
online learning techniques to update the object model. However, these
approaches are heavily invested in the efficiency and effectiveness of their
detectors. Evaluating a massive number of samples for each frame (e.g.,
obtained by a sliding window) forces the detector to trade the accuracy in
favor of speed. Furthermore, misclassification of borderline samples in the
detector introduce accumulating errors in tracking. In this study, we propose a
co-tracking based on the efficient cooperation of two detectors: a rapid
adaptive exemplar-based detector and another more sophisticated but slower
detector with a long-term memory. The sampling labeling and co-learning of the
detectors are conducted by an uncertainty sampling unit, which improves the
speed and accuracy of the system. We also introduce a budgeting mechanism which
prevents the unbounded growth in the number of examples in the first detector
to maintain its rapid response. Experiments demonstrate the efficiency and
effectiveness of the proposed tracker against its baselines and its superior
performance against state-of-the-art trackers on various benchmark videos.Comment: Submitted to IEEE ICSIPA'201
k-Nearest Neighbour Classifiers: 2nd Edition (with Python examples)
Perhaps the most straightforward classifier in the arsenal or machine
learning techniques is the Nearest Neighbour Classifier -- classification is
achieved by identifying the nearest neighbours to a query example and using
those neighbours to determine the class of the query. This approach to
classification is of particular importance because issues of poor run-time
performance is not such a problem these days with the computational power that
is available. This paper presents an overview of techniques for Nearest
Neighbour classification focusing on; mechanisms for assessing similarity
(distance), computational issues in identifying nearest neighbours and
mechanisms for reducing the dimension of the data.
This paper is the second edition of a paper previously published as a
technical report. Sections on similarity measures for time-series, retrieval
speed-up and intrinsic dimensionality have been added. An Appendix is included
providing access to Python code for the key methods.Comment: 22 pages, 15 figures: An updated edition of an older tutorial on kN
Application of advanced machine learning techniques to early network traffic classification
The fast-paced evolution of the Internet is drawing a complex context which
imposes demanding requirements to assure end-to-end Quality of Service. The
development of advanced intelligent approaches in networking is envisioning
features that include autonomous resource allocation, fast reaction against
unexpected network events and so on. Internet Network Traffic Classification
constitutes a crucial source of information for Network Management, being decisive
in assisting the emerging network control paradigms. Monitoring traffic flowing
through network devices support tasks such as: network orchestration, traffic
prioritization, network arbitration and cyberthreats detection, amongst others.
The traditional traffic classifiers became obsolete owing to the rapid Internet
evolution. Port-based classifiers suffer from significant accuracy losses due to port
masking, meanwhile Deep Packet Inspection approaches have severe user-privacy
limitations. The advent of Machine Learning has propelled the application of
advanced algorithms in diverse research areas, and some learning approaches have
proved as an interesting alternative to the classic traffic classification approaches.
Addressing Network Traffic Classification from a Machine Learning perspective
implies numerous challenges demanding research efforts to achieve feasible
classifiers. In this dissertation, we endeavor to formulate and solve important
research questions in Machine-Learning-based Network Traffic Classification. As a
result of numerous experiments, the knowledge provided in this research constitutes
an engaging case of study in which network traffic data from two different
environments are successfully collected, processed and modeled.
Firstly, we approached the Feature Extraction and Selection processes providing our
own contributions. A Feature Extractor was designed to create Machine-Learning
ready datasets from real traffic data, and a Feature Selection Filter based on fast
correlation is proposed and tested in several classification datasets. Then, the
original Network Traffic Classification datasets are reduced using our Selection
Filter to provide efficient classification models. Many classification models based on
CART Decision Trees were analyzed exhibiting excellent outcomes in identifying
various Internet applications. The experiments presented in this research comprise
a comparison amongst ensemble learning schemes, an exploratory study on Class
Imbalance and solutions; and an analysis of IP-header predictors for early traffic
classification. This thesis is presented in the form of compendium of JCR-indexed
scientific manuscripts and, furthermore, one conference paper is included.
In the present work we study a wide number of learning approaches employing the
most advance methodology in Machine Learning. As a result, we identify the
strengths and weaknesses of these algorithms, providing our own solutions to
overcome the observed limitations. Shortly, this thesis proves that Machine
Learning offers interesting advanced techniques that open prominent prospects in
Internet Network Traffic Classification.Departamento de Teoría de la Señal y Comunicaciones e Ingeniería TelemáticaDoctorado en Tecnologías de la Información y las Telecomunicacione
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