11,941 research outputs found
Generative Adversarial Networks (GANs): Challenges, Solutions, and Future Directions
Generative Adversarial Networks (GANs) is a novel class of deep generative
models which has recently gained significant attention. GANs learns complex and
high-dimensional distributions implicitly over images, audio, and data.
However, there exists major challenges in training of GANs, i.e., mode
collapse, non-convergence and instability, due to inappropriate design of
network architecture, use of objective function and selection of optimization
algorithm. Recently, to address these challenges, several solutions for better
design and optimization of GANs have been investigated based on techniques of
re-engineered network architectures, new objective functions and alternative
optimization algorithms. To the best of our knowledge, there is no existing
survey that has particularly focused on broad and systematic developments of
these solutions. In this study, we perform a comprehensive survey of the
advancements in GANs design and optimization solutions proposed to handle GANs
challenges. We first identify key research issues within each design and
optimization technique and then propose a new taxonomy to structure solutions
by key research issues. In accordance with the taxonomy, we provide a detailed
discussion on different GANs variants proposed within each solution and their
relationships. Finally, based on the insights gained, we present the promising
research directions in this rapidly growing field.Comment: 42 pages, Figure 13, Table
Geriatric oncology: problems with under-treatment within this population
We are currently faced with an aging population, which is rapidly growing worldwide. Two thirds of cancer occurs in the over 65-year age group. Societal conceptions from the past have created ageist stereotypes; old age is associated with frailty and the elderly are perceived to be destined for deterioration and loss of independence. Cancer within the elderly is also subject to these stereotypes, with elderly cancer patients considered by some not as likely to recover as younger patients with cancer. We summarise and review the current concerns regarding elderly management and treatments utilised for the management of oncological disease in the elderly, and discuss the impact of under-treatment within this population
On Constant-Round Concurrent Zero-Knowledge from a Knowledge Assumption
In this work, we consider the long-standing open question of constructing
constant-round concurrent zero-knowledge protocols in the plain model.
Resolving this question is known to require non-black-box techniques.
We consider non-black-box techniques for zero-knowledge based on knowledge
assumptions, a line of thinking initiated by the work of Hada and Tanaka
(CRYPTO 1998). Prior to our work, it was not known whether knowledge
assumptions could be used for achieving security in the concurrent setting, due
to a number of significant limitations that we discuss here. Nevertheless, we
obtain the following results:
1. We obtain the first constant round concurrent zero-knowledge argument for
\textbf{NP} in the plain model based on a new variant of knowledge of exponent
assumption. Furthermore, our construction avoids the inefficiency inherent in
previous non-black-box techniques such that those of Barak (FOCS 2001); we
obtain our result through an efficient protocol compiler.
2. Unlike Hada and Tanaka, we do not require a knowledge assumption to argue
the soundness of our protocol. Instead, we use a discrete log like assumption,
which we call Diffie-Hellman Logarithm Assumption, to prove the soundness of
our protocol.
3. We give evidence that our new variant of knowledge of exponent assumption
is in fact plausible. In particular, we show that our assumption holds in the
generic group model.
4. Knowledge assumptions are especially delicate assumptions whose
plausibility may be hard to gauge. We give a novel framework to express
knowledge assumptions in a more flexible way, which may allow for formulation
of plausible assumptions and exploration of their impact and application in
cryptography.Comment: 30 pages, 3 figure
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