76,399 research outputs found
Automated Crowdturfing Attacks and Defenses in Online Review Systems
Malicious crowdsourcing forums are gaining traction as sources of spreading
misinformation online, but are limited by the costs of hiring and managing
human workers. In this paper, we identify a new class of attacks that leverage
deep learning language models (Recurrent Neural Networks or RNNs) to automate
the generation of fake online reviews for products and services. Not only are
these attacks cheap and therefore more scalable, but they can control rate of
content output to eliminate the signature burstiness that makes crowdsourced
campaigns easy to detect.
Using Yelp reviews as an example platform, we show how a two phased review
generation and customization attack can produce reviews that are
indistinguishable by state-of-the-art statistical detectors. We conduct a
survey-based user study to show these reviews not only evade human detection,
but also score high on "usefulness" metrics by users. Finally, we develop novel
automated defenses against these attacks, by leveraging the lossy
transformation introduced by the RNN training and generation cycle. We consider
countermeasures against our mechanisms, show that they produce unattractive
cost-benefit tradeoffs for attackers, and that they can be further curtailed by
simple constraints imposed by online service providers
The Synonym management process in SAREL
The specification phase is one of the most important and least supported
parts of the software development process. The SAREL system has been
conceived as a knowledge-based tool to improve the specification phase.
The purpose of SAREL (Assistance System for Writing Software
Specifications in Natural Language) is to assist engineers in the
creation of software specifications written in Natural Language (NL).
These documents are divided into several parts. We can distinguish the
Introduction and the Overall Description as parts that should be used in
the Knowledge Base construction. The information contained in the
Specific Requirements Section corresponds to the information represented
in the Requirements Base. In order to obtain high-quality software
requirements specification the writing norms that define the linguistic
restrictions required and the software engineering constraints related
to the quality factors have been taken into account. One of the controls
performed is the lexical analysis that verifies the words belong to the
application domain lexicon which consists of the Required and the
Extended lexicon. In this sense a synonym management process is needed
in order to get a quality software specification. The aim of this paper
is to present the synonym management process performed during the
Knowledge Base construction. Such process makes use of the Spanish
Wordnet developed inside the Eurowordnet project. This process generates
both the Required lexicon and the Extended lexicon that will be used
during the Requirements Base construction.Postprint (published version
Optical tomography: Image improvement using mixed projection of parallel and fan beam modes
Mixed parallel and fan beam projection is a technique used to increase the quality images. This research focuses on enhancing the image quality in optical tomography. Image quality can be defined by measuring the Peak Signal to Noise Ratio (PSNR) and Normalized Mean Square Error (NMSE) parameters. The findings of this research prove that by combining parallel and fan beam projection, the image quality can be increased by more than 10%in terms of its PSNR value and more than 100% in terms of its NMSE value compared to a single parallel beam
THE "POWER" OF TEXT PRODUCTION ACTIVITY IN COLLABORATIVE MODELING : NINE RECOMMENDATIONS TO MAKE A COMPUTER SUPPORTED SITUATION WORK
Language is not a direct translation of a speaker’s or writer’s knowledge or intentions. Various complex processes and strategies are involved in serving the needs of the audience: planning the message, describing some features of a model and not others, organizing an argument, adapting to the knowledge of the reader, meeting linguistic constraints, etc. As a consequence, when communicating about a model, or about knowledge, there is a complex interaction between knowledge and language. In this contribution, we address the question of the role of language in modeling, in the specific case of collaboration over a distance, via electronic exchange of written textual information. What are the problems/dimensions a language user has to deal with when communicating a (mental) model? What is the relationship between the nature of the knowledge to be communicated and linguistic production? What is the relationship between representations and produced text? In what sense can interactive learning systems serve as mediators or as obstacles to these processes
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