4,053 research outputs found
Adversarial behaviours knowledge area
The technological advancements witnessed by our society in recent decades have brought
improvements in our quality of life, but they have also created a number of opportunities for
attackers to cause harm. Before the Internet revolution, most crime and malicious activity
generally required a victim and a perpetrator to come into physical contact, and this limited
the reach that malicious parties had. Technology has removed the need for physical contact
to perform many types of crime, and now attackers can reach victims anywhere in the world, as long as they are connected to the Internet. This has revolutionised the characteristics of crime and warfare, allowing operations that would not have been possible before. In this document, we provide an overview of the malicious operations that are happening on the Internet today. We first provide a taxonomy of malicious activities based on the attacker’s motivations and capabilities, and then move on to the technological and human elements that adversaries require to run a successful operation. We then discuss a number of frameworks that have been proposed to model malicious operations. Since adversarial behaviours are not a purely technical topic, we draw from research in a number of fields (computer science, criminology, war studies). While doing this, we discuss how these frameworks can be used by researchers and practitioners to develop effective mitigations against malicious online operations.Published versio
Guided Curriculum Model Adaptation and Uncertainty-Aware Evaluation for Semantic Nighttime Image Segmentation
Most progress in semantic segmentation reports on daytime images taken under
favorable illumination conditions. We instead address the problem of semantic
segmentation of nighttime images and improve the state-of-the-art, by adapting
daytime models to nighttime without using nighttime annotations. Moreover, we
design a new evaluation framework to address the substantial uncertainty of
semantics in nighttime images. Our central contributions are: 1) a curriculum
framework to gradually adapt semantic segmentation models from day to night via
labeled synthetic images and unlabeled real images, both for progressively
darker times of day, which exploits cross-time-of-day correspondences for the
real images to guide the inference of their labels; 2) a novel
uncertainty-aware annotation and evaluation framework and metric for semantic
segmentation, designed for adverse conditions and including image regions
beyond human recognition capability in the evaluation in a principled fashion;
3) the Dark Zurich dataset, which comprises 2416 unlabeled nighttime and 2920
unlabeled twilight images with correspondences to their daytime counterparts
plus a set of 151 nighttime images with fine pixel-level annotations created
with our protocol, which serves as a first benchmark to perform our novel
evaluation. Experiments show that our guided curriculum adaptation
significantly outperforms state-of-the-art methods on real nighttime sets both
for standard metrics and our uncertainty-aware metric. Furthermore, our
uncertainty-aware evaluation reveals that selective invalidation of predictions
can lead to better results on data with ambiguous content such as our nighttime
benchmark and profit safety-oriented applications which involve invalid inputs.Comment: ICCV 2019 camera-read
Every Smile is Unique: Landmark-Guided Diverse Smile Generation
Each smile is unique: one person surely smiles in different ways (e.g.,
closing/opening the eyes or mouth). Given one input image of a neutral face,
can we generate multiple smile videos with distinctive characteristics? To
tackle this one-to-many video generation problem, we propose a novel deep
learning architecture named Conditional Multi-Mode Network (CMM-Net). To better
encode the dynamics of facial expressions, CMM-Net explicitly exploits facial
landmarks for generating smile sequences. Specifically, a variational
auto-encoder is used to learn a facial landmark embedding. This single
embedding is then exploited by a conditional recurrent network which generates
a landmark embedding sequence conditioned on a specific expression (e.g.,
spontaneous smile). Next, the generated landmark embeddings are fed into a
multi-mode recurrent landmark generator, producing a set of landmark sequences
still associated to the given smile class but clearly distinct from each other.
Finally, these landmark sequences are translated into face videos. Our
experimental results demonstrate the effectiveness of our CMM-Net in generating
realistic videos of multiple smile expressions.Comment: Accepted as a poster in Conference on Computer Vision and Pattern
Recognition (CVPR), 201
- …