6,881 research outputs found
Communications in cellular automata
The goal of this paper is to show why the framework of communication
complexity seems suitable for the study of cellular automata. Researchers have
tackled different algorithmic problems ranging from the complexity of
predicting to the decidability of different dynamical properties of cellular
automata. But the difference here is that we look for communication protocols
arising in the dynamics itself. Our work is guided by the following idea: if we
are able to give a protocol describing a cellular automaton, then we can
understand its behavior
Reversibility in space, time, and computation: the case of underwater acoustic communications
Time reversal of waves has been successfully used in communications, sensing
and imaging for decades. The application in underwater acoustic communications
is of our special interest, as it puts together a reversible process (allowing
a reversible software or hardware realisation) and a reversible medium
(allowing a reversible model of the environment). This work in progress report
addresses the issues of modelling, analysis and implementation of acoustic time
reversal from the reversible computation perspective. We show the potential of
using reversible cellular automata for modelling and quantification of
reversibility in the time reversal communication process. Then we present an
implementation of time reversal hardware based on reversible circuits.Comment: 7 pages, RC 2018 Work in Progress pape
Exploring the Dynamics of Fungal Cellular Automata
Cells in a fungal hyphae are separated by internal walls (septa). The septa
have tiny pores that allow cytoplasm flowing between cells. Cells can close
their septa blocking the flow if they are injured, preventing fluid loss from
the rest of filament. This action is achieved by special organelles called
Woronin bodies. Using the controllable pores as an inspiration we advance one
and two-dimensional cellular automata into Elementary fungal cellular automata
(EFCA) and Majority fungal automata (MFA) by adding a concept of Woronin bodies
to the cell state transition rules. EFCA is a cellular automaton where the
communications between neighboring cells can be blocked by the activation of
the Woronin bodies (Wb), allowing or blocking the flow of information
(represented by a cytoplasm and chemical elements it carries) between them. We
explore a novel version of the fungal automata where the evolution of the
system is only affected by the activation of the Wb. We explore two case
studies: the Elementary Fungal Cellular Automata (EFCA), which is a direct
application of this variant for elementary cellular automata rules, and the
Majority Fungal Automata (MFA), which correspond to an application of the Wb to
two dimensional automaton with majority rule with Von Neumann neighborhood. By
studying the EFCA model, we analyze how the 256 elementary cellular automata
rules are affected by the activation of Wb in different modes, increasing the
complexity on applied rule in some cases. Also we explore how a consensus over
MFA is affected when the continuous flow of information is interrupted due to
the activation of Woronin bodies.Comment: 31 pages, 30 figure
Towards Physiology-Aware DASH: Bandwidth-Compliant Prioritized Clinical Multimedia Communication in Ambulances
The ultimate objective of medical cyber-physical systems is to enhance the
safety and effectiveness of patient care. To ensure safe and effective care
during emergency patient transfer from rural areas to center tertiary
hospitals, reliable and real-time communication is essential. Unfortunately,
real-time monitoring of patients involves transmission of various clinical
multimedia data including videos, medical images, and vital signs, which
requires use of mobile network with high-fidelity communication bandwidth.
However, the wireless networks along the roads in rural areas range from 4G to
2G to low speed satellite links, which poses a significant challenge to
transmit critical patient information.
In this paper, we present a bandwidth-compliant criticality-aware system for
transmission of massive clinical multimedia data adaptive to varying bandwidths
during patient transport. Model-based clinical automata are used to determine
the criticality of clinical multimedia data. We borrow concepts from DASH, and
propose physiology-aware adaptation techniques to transmit more critical
clinical data with higher fidelity in response to changes in disease, clinical
states, and bandwidth condition. In collaboration with Carle's ambulance
service center, we develop a bandwidth profiler, and use it as proof of concept
to support our experiments. Our preliminary evaluation results show that our
solutions ensure that most critical patient's clinical data are communicated
with higher fidelity.Comment: 15 pages, IEEE Transactions on Multimedia (TMM), 201
Differentiable cellular automata
We describe a class of cellular automata (CAs) that are end-to-end
differentiable. DCAs interpolate the behavior of ordinary CAs through rules
that act on distributions of states. The gradient of a DCA with respect to its
parameters can be computed with an iterative propagation scheme that uses
previously-computed gradients and values. Gradient-based optimization over DCAs
could be used to find ordinary CAs with desired properties
On the Use of Cellular Automata in Symmetric Cryptography
In this work, pseudorandom sequence generators based on finite fields have
been analyzed from the point of view of their cryptographic application. In
fact, a class of nonlinear sequence generators has been modelled in terms of
linear cellular automata. The algorithm that converts the given generator into
a linear model based on automata is very simple and is based on the
concatenation of a basic structure. Once the generator has been linearized, a
cryptanalytic attack that exploits the weaknesses of such a model has been
developed. Linear cellular structures easily model sequence generators with
application in stream cipher cryptography.Comment: 25 pages, 0 figure
Pseudorandom sequences in spread-spectrum communications generated by cellular automata
"Dynamical systems methods have been recently used in spread-spectrum digital communication systems. The expansion of the spectrum using a pseudorandom sequence with a higher frequency than the information signal is the key feature for its robustness against the signal traveling interference through the channel. In this work, we propose to generate pseudorandom sequences by employing cellular automata and we check these sequences have the necessary properties which are required in modern communication systems. The computed sequences obtained by the cellular automata are tested in a quadrature phase shift keying (QPSK) spread-spectrum communication system. The efficiency of the system is analyzed by computing the bit error rate under different signal to noise ratio conditions. These results are compared with systems that employ Golden code and other typical pseudorandom sequences.
Ergodicity of PCA: Equivalence between Spatial and Temporal Mixing Conditions
For a general attractive Probabilistic Cellular Automata on S Z d , we prove
that the (time-) convergence towards equilibrium of this Markovian parallel
dynamics, exponentially fast in the uniform norm, is equivalent to a condition
(A). This condition means the exponential decay of the inuence from the
boundary for the invariant measures of the system restricted to nite boxes. For
a class of reversible PCA dynamics on {--1, +1} Z d , with a naturally
associated Gibbsian potential , we prove that a (spatial-) weak mixing
condition (WM) for implies the validity of the assumption (A); thus
exponential (time-) ergodicity of these dynamics towards the unique Gibbs
measure associated to holds. On some particular examples we state
that exponential ergodicity holds as soon as there is no phase transition.Comment: in Electronic Communications in Probability, Institute of
Mathematical Statistics (IMS), 200
Fuzzy cellular model for on-line traffic simulation
This paper introduces a fuzzy cellular model of road traffic that was
intended for on-line applications in traffic control. The presented model uses
fuzzy sets theory to deal with uncertainty of both input data and simulation
results. Vehicles are modelled individually, thus various classes of them can
be taken into consideration. In the proposed approach, all parameters of
vehicles are described by means of fuzzy numbers. The model was implemented in
a simulation of vehicles queue discharge process. Changes of the queue length
were analysed in this experiment and compared to the results of NaSch cellular
automata model.Comment: The original publication is available at http://www.springerlink.co
Self-Organization in Traffic Lights: Evolution of Signal Control with Advances in Sensors and Communications
Traffic signals are ubiquitous devices that first appeared in 1868. Recent
advances in information and communications technology (ICT) have led to
unprecedented improvements in such areas as mobile handheld devices (i.e.,
smartphones), the electric power industry (i.e., smart grids), transportation
infrastructure, and vehicle area networks. Given the trend towards
interconnectivity, it is only a matter of time before vehicles communicate with
one another and with infrastructure. In fact, several pilots of such
vehicle-to-vehicle and vehicle-to-infrastructure (e.g. traffic lights and
parking spaces) communication systems are already operational. This survey of
autonomous and self-organized traffic signaling control has been undertaken
with these potential developments in mind. Our research results indicate that,
while many sophisticated techniques have attempted to improve the scheduling of
traffic signal control, either real-time sensing of traffic patterns or a
priori knowledge of traffic flow is required to optimize traffic. Once this is
achieved, communication between traffic signals will serve to vastly improve
overall traffic efficiency
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