3 research outputs found
Robust Classification with Convolutional Prototype Learning
Convolutional neural networks (CNNs) have been widely used for image
classification. Despite its high accuracies, CNN has been shown to be easily
fooled by some adversarial examples, indicating that CNN is not robust enough
for pattern classification. In this paper, we argue that the lack of robustness
for CNN is caused by the softmax layer, which is a totally discriminative model
and based on the assumption of closed world (i.e., with a fixed number of
categories). To improve the robustness, we propose a novel learning framework
called convolutional prototype learning (CPL). The advantage of using
prototypes is that it can well handle the open world recognition problem and
therefore improve the robustness. Under the framework of CPL, we design
multiple classification criteria to train the network. Moreover, a prototype
loss (PL) is proposed as a regularization to improve the intra-class
compactness of the feature representation, which can be viewed as a generative
model based on the Gaussian assumption of different classes. Experiments on
several datasets demonstrate that CPL can achieve comparable or even better
results than traditional CNN, and from the robustness perspective, CPL shows
great advantages for both the rejection and incremental category learning
tasks
Finding prototypes for nearest neighbour classification by means of gradient descent and deterministic annealing
info:eu-repo/semantics/publishe
Learning in the Real World: Constraints on Cost, Space, and Privacy
The sheer demand for machine learning in fields as varied as: healthcare, web-search ranking, factory automation, collision prediction, spam filtering, and many others, frequently outpaces the intended use-case of machine learning models. In fact, a growing number of companies hire machine learning researchers to rectify this very problem: to tailor and/or design new state-of-the-art models to the setting at hand.
However, we can generalize a large set of the machine learning problems encountered in practical settings into three categories: cost, space, and privacy. The first category (cost) considers problems that need to balance the accuracy of a machine learning model with the cost required to evaluate it. These include problems in web-search, where results need to be delivered to a user in under a second and be as accurate as possible. The second category (space) collects problems that require running machine learning algorithms on low-memory computing devices. For instance, in search-and-rescue operations we may opt to use many small unmanned aerial vehicles (UAVs) equipped with machine learning algorithms for object detection to find a desired search target. These algorithms should be small to fit within the physical memory limits of the UAV (and be energy efficient) while reliably detecting objects. The third category (privacy) considers problems where one wishes to run machine learning algorithms on sensitive data. It has been shown that seemingly innocuous analyses on such data can be exploited to reveal data individuals would prefer to keep private. Thus, nearly any algorithm that runs on patient or economic data falls under this set of problems.
We devise solutions for each of these problem categories including (i) a fast tree-based model for explicitly trading off accuracy and model evaluation time, (ii) a compression method for the k-nearest neighbor classifier, and (iii) a private causal inference algorithm that protects sensitive data