378 research outputs found
Studying Parallel Evolutionary Algorithms: The cellular Programming Case
Parallel evolutionary algorithms, studied to some extent over the past few years, have proven empirically worthwhile—though there seems to be lacking a better understanding of their workings. In this paper we concentrate on cellular (fine-grained) models, presenting a number of statistical measures, both at the genotypic and phenotypic levels. We demonstrate the application and utility of these measures on a specific example, that of the cellular programming evolutionary algorithm, when used to evolve solutions to a hard problem in the cellular-automata domain, known as synchronization
A dynamic programming approach to planning with decision networks
Ph.D.J. Gordon Davi
High Per Parameter: A Large-Scale Study of Hyperparameter Tuning for Machine Learning Algorithms
Hyperparameters in machine learning (ML) have received a fair amount of
attention, and hyperparameter tuning has come to be regarded as an important
step in the ML pipeline. But just how useful is said tuning? While
smaller-scale experiments have been previously conducted, herein we carry out a
large-scale investigation, specifically, one involving 26 ML algorithms, 250
datasets (regression and both binary and multinomial classification), 6 score
metrics, and 28,857,600 algorithm runs. Analyzing the results we conclude that
for many ML algorithms we should not expect considerable gains from
hyperparameter tuning on average, however, there may be some datasets for which
default hyperparameters perform poorly, this latter being truer for some
algorithms than others. By defining a single hp_score value, which combines an
algorithm's accumulated statistics, we are able to rank the 26 ML algorithms
from those expected to gain the most from hyperparameter tuning to those
expected to gain the least. We believe such a study may serve ML practitioners
at large
Parity Problem With A Cellular Automaton Solution
The parity of a bit string of length is a global quantity that can be
efficiently compute using a global counter in time. But is it
possible to find the parity using cellular automata with a set of local rule
tables without using any global counter? Here, we report a way to solve this
problem using a number of binary, uniform, parallel and deterministic
cellular automata applied in succession for a total of time.Comment: Revtex, 4 pages, final version accepted by Phys.Rev.
A Simple Cellular Automation that Solves the Density and Ordering Problems
Cellular automata (CA) are discrete, dynamical systems that perform computations
in a distributed fashion on a spatially extended grid. The dynamical behavior
of a CA may give rise to emergent computation, referring to the appearance of
global information processing capabilities that are not explicitly represented in the
system's elementary components nor in their local interconnections.1 As such, CAs
o?er an austere yet versatile model for studying natural phenomena, as well as a
powerful paradigm for attaining ?ne-grained, massively parallel computation.
An example of such emergent computation is to use a CA to determine the
global density of bits in an initial state con?guration. This problem, known as
density classi?cation, has been studied quite intensively over the past few years. In
this short communication we describe two previous versions of the problem along with their CA solutions, and then go on to show that there exists yet a third version
| which admits a simple solution
I See Dead People: Gray-Box Adversarial Attack on Image-To-Text Models
Modern image-to-text systems typically adopt the encoder-decoder framework,
which comprises two main components: an image encoder, responsible for
extracting image features, and a transformer-based decoder, used for generating
captions. Taking inspiration from the analysis of neural networks' robustness
against adversarial perturbations, we propose a novel gray-box algorithm for
creating adversarial examples in image-to-text models. Unlike image
classification tasks that have a finite set of class labels, finding visually
similar adversarial examples in an image-to-text task poses greater challenges
because the captioning system allows for a virtually infinite space of possible
captions. In this paper, we present a gray-box adversarial attack on
image-to-text, both untargeted and targeted. We formulate the process of
discovering adversarial perturbations as an optimization problem that uses only
the image-encoder component, meaning the proposed attack is language-model
agnostic. Through experiments conducted on the ViT-GPT2 model, which is the
most-used image-to-text model in Hugging Face, and the Flickr30k dataset, we
demonstrate that our proposed attack successfully generates visually similar
adversarial examples, both with untargeted and targeted captions. Notably, our
attack operates in a gray-box manner, requiring no knowledge about the decoder
module. We also show that our attacks fool the popular open-source platform
Hugging Face
Open Sesame! Universal Black Box Jailbreaking of Large Language Models
Large language models (LLMs), designed to provide helpful and safe responses,
often rely on alignment techniques to align with user intent and social
guidelines. Unfortunately, this alignment can be exploited by malicious actors
seeking to manipulate an LLM's outputs for unintended purposes. In this paper
we introduce a novel approach that employs a genetic algorithm (GA) to
manipulate LLMs when model architecture and parameters are inaccessible. The GA
attack works by optimizing a universal adversarial prompt that -- when combined
with a user's query -- disrupts the attacked model's alignment, resulting in
unintended and potentially harmful outputs. Our novel approach systematically
reveals a model's limitations and vulnerabilities by uncovering instances where
its responses deviate from expected behavior. Through extensive experiments we
demonstrate the efficacy of our technique, thus contributing to the ongoing
discussion on responsible AI development by providing a diagnostic tool for
evaluating and enhancing alignment of LLMs with human intent. To our knowledge
this is the first automated universal black box jailbreak attack
Pseudorandom number generation based on controllable cellular automata
A novel Cellular Automata (CA) Controllable CA (CCA) is proposed in this paper. Further, CCA are applied in Pseudorandom Number Generation. Randomness test results on CCA Pseudorandom Number Generators (PRNGs) show that they are better than 1-d CA PRNGs and can be comparable to 2-d ones. But they do not lose the structure simplicity of 1-d CA. Further, we develop several different types of CCA PRNGs. Based on the comparison of the randomness of different CCA PRNGs, we find that their properties are decided by the actions of the controllable cells and their neighbors. These novel CCA may be applied in other applications where structure non-uniformity or asymmetry is desired
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