162 research outputs found
Media Forensics and DeepFakes: an overview
With the rapid progress of recent years, techniques that generate and
manipulate multimedia content can now guarantee a very advanced level of
realism. The boundary between real and synthetic media has become very thin. On
the one hand, this opens the door to a series of exciting applications in
different fields such as creative arts, advertising, film production, video
games. On the other hand, it poses enormous security threats. Software packages
freely available on the web allow any individual, without special skills, to
create very realistic fake images and videos. So-called deepfakes can be used
to manipulate public opinion during elections, commit fraud, discredit or
blackmail people. Potential abuses are limited only by human imagination.
Therefore, there is an urgent need for automated tools capable of detecting
false multimedia content and avoiding the spread of dangerous false
information. This review paper aims to present an analysis of the methods for
visual media integrity verification, that is, the detection of manipulated
images and videos. Special emphasis will be placed on the emerging phenomenon
of deepfakes and, from the point of view of the forensic analyst, on modern
data-driven forensic methods. The analysis will help to highlight the limits of
current forensic tools, the most relevant issues, the upcoming challenges, and
suggest future directions for research
Collaborative adaptive accessibility and human capabilities
This thesis discusses the challenges and opportunities facing the field of accessibility, particularly as computing becomes ubiquitous. It is argued that a new approach is needed that centres around adaptations (specific, atomic changes) to user interfaces and content in order to improve their accessibility for a wider range of people than targeted by present Assistive Technologies (ATs). Further, the approach must take into consideration the capabilities of people at the human level and facilitate collaboration, in planned and ad-hoc environments.
There are two main areas of focus: (1) helping people experiencing minor-to-moderate, transient and potentially-overlapping impairments, as may be brought about by the ageing process and (2) supporting collaboration between people by reasoning about the consequences, from different users perspectives, of the adaptations they may require.
A theoretical basis for describing these problems and a reasoning process for the semi-automatic application of adaptations is developed. Impairments caused by the environment in which a device is being used are considered. Adaptations are drawn from other research and industry artefacts. Mechanical testing is carried out on key areas of the reasoning process, demonstrating fitness for purpose.
Several fundamental techniques to extend the reasoning process in order to take temporal factors (such as fluctuating user and device capabilities) into account are broadly described. These are proposed to be feasible, though inherently bring compromises (which are defined) in interaction stability and the needs of different actors (user, device, target level of accessibility).
This technical work forms the basis of the contribution of one work-package of the Sustaining ICT use to promote autonomy (Sus-IT) project, under the New Dynamics of Ageing (NDA) programme of research in the UK. Test designs for larger-scale assessment of the system with real-world participants are given. The wider Sus-IT project provides social motivations and informed design decisions for this work and is carrying out longitudinal acceptance testing of the processes developed here
L2 learners' knowledge of verb form-function relationships at different stages in the acquisition of English as a second language : a study of college learners' interlanguage in Zaire.
Available from British Library Document Supply Centre- DSC:D97832 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Anatomical Variation and Clinical Diagnosis
In the anatomical sciences, it has long been recognized that the human body displays a range of morphological patterns and arrangements, often termed “anatomical variation”. Variations are relatively common throughout the body and may cause or contribute to significant medical conditions. An understanding of normal anatomical variation is vital for performing a broad range of surgical and other medical procedures and treatment modalities. However, despite their importance to effective diagnosis and treatment, such variations are often overlooked in medical school curricula and clinical practice. Recent advances in imaging techniques and a renewed interest in variation in dissection-based gross anatomy laboratories have facilitated the identification of many such variants. The aim of this Special Issue of Diagnostics is to highlight previously under-recognized anatomical variations and to discuss them in a clinical context. In particular, this Special Issue focuses on variants that have specific implications for diagnosis and treatment and explores their potential consequences. The scope of this Special Issue includes studies on gross anatomy, radiology, surgical anatomy, histology, and neuroanatomy
A MODEL FOR PREDICTING THE PERFORMANCE OF IP VIDEOCONFERENCING
With the incorporation of free desktop videoconferencing (DVC) software on the
majority of the world's PCs, over the recent years, there has, inevitably, been considerable
interest in using DVC over the Internet. The growing popularity of DVC
increases the need for multimedia quality assessment. However, the task of predicting
the perceived multimedia quality over the Internet Protocol (IP) networks is
complicated by the fact that the audio and video streams are susceptible to unique
impairments due to the unpredictable nature of IP networks, different types of task
scenarios, different levels of complexity, and other related factors. To date, a standard
consensus to define the IP media Quality of Service (QoS) has yet to be implemented.
The thesis addresses this problem by investigating a new approach to
assess the quality of audio, video, and audiovisual overall as perceived in low cost
DVC systems.
The main aim of the thesis is to investigate current methods used to assess the perceived
IP media quality, and then propose a model which will predict the quality of
audiovisual experience from prevailing network parameters.
This thesis investigates the effects of various traffic conditions, such as, packet loss,
jitter, and delay and other factors that may influence end user acceptance, when low
cost DVC is used over the Internet. It also investigates the interaction effects between
the audio and video media, and the issues involving the lip sychronisation
error. The thesis provides the empirical evidence that the subjective mean opinion
score (MOS) of the perceived multimedia quality is unaffected by lip synchronisation
error in low cost DVC systems.
The data-gathering approach that is advocated in this thesis involves both field and
laboratory trials to enable the comparisons of results between classroom-based experiments
and real-world environments to be made, and to provide actual real-world
confirmation of the bench tests. The subjective test method was employed
since it has been proven to be more robust and suitable for the research studies, as
compared to objective testing techniques.
The MOS results, and the number of observations obtained, have enabled a set of
criteria to be established that can be used to determine the acceptable QoS for given
network conditions and task scenarios. Based upon these comprehensive findings,
the final contribution of the thesis is the proposal of a new adaptive architecture
method that is intended to enable the performance of IP based DVC of a particular
session to be predicted for a given network condition
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