179,326 research outputs found
An Empirical Analysis on Point-wise Machine Learning Techniques using Regression Trees for Web-search Ranking
Learning how to rank a set of objects relative to an user defined query has received much interest in the machine learning community during the past decade. In fact, there have been two recent competitions hosted by internationally prominent search companies to encourage research on ranking web site documents. Recent literature on learning to rank has focused on three approaches: point-wise, pair-wise, and list-wise. Many different kinds of classifiers, including boosted decision trees, neural networks, and SVMs have proven successful in the field. This thesis surveys traditional point-wise techniques that use regression trees for web-search ranking. The thesis contains empirical studies on Random Forests and Gradient Boosted Decision Trees, with novel augmentations to them on real world data sets. We also analyze how these point-wise techniques perform on new areas of research for web-search ranking: transfer learning and feature-cost aware models
NCART: Neural Classification and Regression Tree for Tabular Data
Deep learning models have become popular in the analysis of tabular data, as
they address the limitations of decision trees and enable valuable applications
like semi-supervised learning, online learning, and transfer learning. However,
these deep-learning approaches often encounter a trade-off. On one hand, they
can be computationally expensive when dealing with large-scale or
high-dimensional datasets. On the other hand, they may lack interpretability
and may not be suitable for small-scale datasets. In this study, we propose a
novel interpretable neural network called Neural Classification and Regression
Tree (NCART) to overcome these challenges. NCART is a modified version of
Residual Networks that replaces fully-connected layers with multiple
differentiable oblivious decision trees. By integrating decision trees into the
architecture, NCART maintains its interpretability while benefiting from the
end-to-end capabilities of neural networks. The simplicity of the NCART
architecture makes it well-suited for datasets of varying sizes and reduces
computational costs compared to state-of-the-art deep learning models.
Extensive numerical experiments demonstrate the superior performance of NCART
compared to existing deep learning models, establishing it as a strong
competitor to tree-based models
Geometric Heuristics for Transfer Learning in Decision Trees
Motivated by a network fault detection problem, we study how
recall can be boosted in a decision tree classifier, without sacrificing
too much precision. This problem is relevant and novel in the context of transfer learning (TL), in which few target domain training
samples are available. We define a geometric optimization problem
for boosting the recall of a decision tree classifier, and show it is
NP-hard. To solve it efficiently, we propose several near-linear time
heuristics, and experimentally validate these heuristics in the context of TL. Our evaluation includes 7 public datasets, as well as 6
network fault datasets, and we compare our heuristics with several
existing TL algorithms, as well as exact mixed integer linear programming (MILP) solutions to our optimization problem. We find
that our heuristics boost recall in a manner similar to optimal MILP
solutions, yet require several orders of magnitude less compute
time. In many cases th
Transfer Learning for Detecting Unknown Network Attacks
Network attacks are serious concerns in today’s increasingly interconnected society. Recent studies have applied conventional machine learning to network attack detection by learning the patterns of the network behaviors and training a classification model. These models usually require large labeled datasets; however, the rapid pace and unpredictability of cyber attacks make this labeling impossible in real time. To address these problems, we proposed utilizing transfer learning for detecting new and unseen attacks by transferring the knowledge of the known attacks. In our previous work, we have proposed a transfer learning-enabled framework and approach, called HeTL, which can find the common latent subspace of two different attacks and learn an optimized representation, which was invariant to attack behaviors’ changes. However, HeTL relied on manual pre-settings of hyper-parameters such as relativeness between the source and target attacks. In this paper, we extended this study by proposing a clustering-enhanced transfer learning approach, called CeHTL, which can automatically find the relation between the new attack and known attack. We evaluated these approaches by stimulating scenarios where the testing dataset contains different attack types or subtypes from the training set. We chose several conventional classification models such as decision trees, random forests, KNN, and other novel transfer learning approaches as strong baselines. Results showed that proposed HeTL and CeHTL improved the performance remarkably. CeHTL performed best, demonstrating the effectiveness of transfer learning in detecting new network attacks
Learning Parse and Translation Decisions From Examples With Rich Context
We present a knowledge and context-based system for parsing and translating
natural language and evaluate it on sentences from the Wall Street Journal.
Applying machine learning techniques, the system uses parse action examples
acquired under supervision to generate a deterministic shift-reduce parser in
the form of a decision structure. It relies heavily on context, as encoded in
features which describe the morphological, syntactic, semantic and other
aspects of a given parse state.Comment: 8 pages, LaTeX, 3 postscript figures, uses aclap.st
- …