scholarly journals Networks of Picture Processors with Filtering Based on Evaluation Sets as Solvers for Cryptographic Puzzles Based on Random Multivariate Quadratic Equations

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2160
Author(s):  
Karina Paola Jiménez ◽  
Sandra Gómez-Canaval ◽  
Ricardo Villanueva-Polanco ◽  
Silvia Martín Suazo
Keyword(s):  
Computational Models ◽  
Selection Process ◽  
Efficient Solutions ◽  
Wide Field ◽  
Quadratic Polynomials ◽  
Quadratic Equations ◽  
Cellular Processes ◽  
Complete Problems ◽  
Hardware Implementations ◽  
Cryptographic Puzzles

Networks of picture processors is a massively distributed and parallel computational model inspired by the evolutionary cellular processes, which offers efficient solutions for NP-complete problems. This bio-inspired model computes two-dimensional strings (pictures) using simple rewriting rules (evolutionary operations). The functioning of this model mimics a community of cells (pictures) that are evolving according to these bio-operations via a selection process that filters valid surviving cells. In this paper, we propose an extension of this model that empowers it with a flexible method that selects the processed pictures based on a quantitative evaluation of its content. In order to show the versatility of this extension, we introduce a solver for a cryptographic proof-of-work based on the hardness of finding a solution to a set of random quadratic equations over the finite field F2. This problem is demonstrated to be NP-hard, even with quadratic polynomials over the field F2, when the number of equations and the number of variables are of roughly the same size. The proposed solution runs in O(n2) computational steps for any size (n,m) of the input pictures. In this context, this paper opens up a wide field of research that looks for theoretical and practical solutions of cryptographic problems via software/hardware implementations based on bio-inspired computational models.

scholarly journals Feature-based data assimilation in geophysics

2017 ◽  
Author(s):  
Matthias Morzfeld ◽  
Jesse Adams ◽  
Spencer Lunderman ◽  
Rafael Orozco
Keyword(s):  
Computational Models ◽  
Chaotic Systems ◽  
Efficient Solutions ◽  
Effective Dimension ◽  
Dimensional Model ◽  
Computationally Efficient ◽  
Fundamental Understanding ◽  
Feature Based ◽  
Low Dimensional ◽  
Noise Models

Abstract. Many applications in science require that computational models and data be combined. In a Bayesian framework, this is usually done by defining likelihoods based on the mismatch of model outputs and data. However, matching model outputs and data in this way can be unnecessary or impossible. For example, using large amounts of steady state data is unnecessary because these data are redundant, it is numerically difficult to assimilate data in chaotic systems, and it is often impossible to assimilate data of a complex system into a low-dimensional model. These issues can be addressed by selecting features of the data, and defining likelihoods based on the features, rather than by the usual mismatch of model output and data. Our goal is to contribute to a fundamental understanding of such a feature-based approach that allows us to assimilate selected aspects of data into models. Specifically, we explain how the feature-based approach can be interpreted as a method for reducing an effective dimension, and derive new noise models, based on perturbed observations, that lead to computationally efficient solutions. Numerical implementations of our ideas are illustrated in four examples.

scholarly journals Research on GF-6 Data Selection Technology for Fine Classification of Forest Land

2019 ◽  
Vol 131 ◽  
pp. 01064 ◽  
Author(s):  
Guang Deng ◽  
Peng Zhang ◽  
Zhiyong Li ◽  
xin Tian
Keyword(s):  
Satellite Data ◽  
Selection Process ◽  
Data Availability ◽  
Data Selection ◽  
Wide Field ◽  
Large Area ◽  
Business Applications ◽  
The Face ◽  
Screening Efficiency ◽  
Selection Stage

GF-6 satellite is a kind of high-resolution satellites launched by China in recent years. Its sensors have the characteristics of multispectrals, wide field of view, high spatial resolution and high frequency imaging. In order to carry out fine identification of forest types, this paper proposes a method to improve data screening efficiency and data availability rate in GF-6 satellite data selection stage. This paper describes the selection process and key technical methods of GF-6 satellite data, and gives a verification program. It has been proved that the program meets the design objectives and can quickly scree out the required fast screening technologies in the face of massive data and large-area business applications, thus increasing the degree of automation and reducing the workload of manual visual selection.

scholarly journals Modelling auditory attention

2017 ◽  
Vol 372 (1714) ◽  
pp. 20160101 ◽  
Author(s):  
Emine Merve Kaya ◽  
Mounya Elhilali
Keyword(s):  
Computational Models ◽  
Selection Process ◽  
Relevant Information ◽  
Auditory Attention ◽  
Cognitive Resources ◽  
Cocktail Party Problem ◽  
Modelling Studies ◽  
Pertinent Information ◽  
Current Article ◽  
Auditory Scenes

Sounds in everyday life seldom appear in isolation. Both humans and machines are constantly flooded with a cacophony of sounds that need to be sorted through and scoured for relevant information—a phenomenon referred to as the ‘cocktail party problem’. A key component in parsing acoustic scenes is the role of attention, which mediates perception and behaviour by focusing both sensory and cognitive resources on pertinent information in the stimulus space. The current article provides a review of modelling studies of auditory attention. The review highlights how the term attention refers to a multitude of behavioural and cognitive processes that can shape sensory processing. Attention can be modulated by ‘bottom-up’ sensory-driven factors, as well as ‘top-down’ task-specific goals, expectations and learned schemas. Essentially, it acts as a selection process or processes that focus both sensory and cognitive resources on the most relevant events in the soundscape; with relevance being dictated by the stimulus itself (e.g. a loud explosion) or by a task at hand (e.g. listen to announcements in a busy airport). Recent computational models of auditory attention provide key insights into its role in facilitating perception in cluttered auditory scenes. This article is part of the themed issue ‘Auditory and visual scene analysis’.

scholarly journals Interactive Multiresolution Visualization of Cellular Network Processes

2019 ◽  
Author(s):  
Oscar O. Ortega ◽  
Carlos F. Lopez
Keyword(s):  
Computational Models ◽  
Dynamic Network ◽  
Cellular Systems ◽  
Biochemical Network ◽  
Mitochondrial Outer Membrane ◽  
Cellular Processes ◽  
Detection Algorithms ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Extrinsic Apoptosis ◽  
Dynamic Execution

AbstractComputational models of network-driven processes have become a standard to explain cellular systems-level behavior and predict cellular responses to perturbations. Modern models can span a broad range of biochemical reactions and species that, in principle, comprise the complexity of dynamic cellular processes. Visualization plays a central role in the analysis of biochemical network processes to identify patterns that arise from model dynamics and perform model exploratory analysis. However, most existing visualization tools are limited in their capabilities to facilitate mechanism exploration of large, dynamic, and complex models. Here, we present PyViPR, a visualization tool that provides researchers static and dynamic representations of biochemical network processes within a Python-based Literate Programming environment. PyViPR embeds network visualizations on Jupyter notebooks, thus facilitating integration with Python modeling, simulation, and analysis workflows. To present the capabilities of PyViPR, we explore execution mechanisms of extrinsic apoptosis in HeLa cells. We show how community-detection algorithms can identify groups of molecular species that represent key biological regulatory functions and simplify the apoptosis network by placing those groups into interactively collapsible nodes. We then show how dynamic execution of a signal, under different kinetic parameter sets that fit the experimental data equally well, exhibit significantly different signal-execution modes in mitochondrial outer-membrane permeabilization – the point of no return in extrinsic apoptosis execution. Therefore, PyViPR aids the conceptual understanding of dynamic network processes and accelerates hypothesis generation for further testing and validation.

scholarly journals On Distributed Solution to SAT by Membrane Computing

2018 ◽  
Vol 13 (3) ◽  
pp. 303-320 ◽  
Author(s):  
Henry N. Adorna ◽  
Linqiang Pan ◽  
Bosheng Song
Keyword(s):  
Cell Division ◽  
Computational Models ◽  
P Systems ◽  
Boolean Formula ◽  
Sat Problem ◽  
Complete Problems ◽  
Uniform Solution ◽  
Boolean Formulas ◽  
The Given ◽  
Communication Resource

Tissue P systems with evolutional communication rules and cell division (TPec, for short) are a class of bio-inspired parallel computational models, which can solve NP-complete problems in a feasible time. In this work, a variant of TPec, called $k$-distributed tissue P systems with evolutional communication and cell division ($k\text{-}\Delta_{TP_{ec}}$, for short) is proposed. A uniform solution to the SAT problem by $k\text{-}\Delta_{TP_{ec}}$ under balanced fixed-partition is presented. The solution provides not only the precise satisfying truth assignments for all Boolean formulas, but also a precise amount of possible such satisfying truth assignments. It is shown that the communication resource for one-way and two-way uniform $k$-P protocols are increased with respect to $k$; while a single communication is shown to be possible for bi-directional uniform $k$-P protocols for any $k$. We further show that if the number of clauses is at least equal to the square of the number of variables of the given boolean formula, then $k\text{-}\Delta_{TP_{ec}}$ for solving the SAT problem are more efficient than TPec as show in \cite{bosheng2017}; if the number of clauses is equal to the number of variables, then $k\text{-}\Delta_{TP_{ec}}$ for solving the SAT problem work no much faster than TPec.

scholarly journals Tuning Frontiers of Efficiency in Tissue P Systems with Evolutional Communication Rules

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
David Orellana-Martín ◽  
Luis Valencia-Cabrera ◽  
Bosheng Song ◽  
Linqiang Pan ◽  
Mario J. Pérez-Jiménez
Keyword(s):  
Polynomial Time ◽  
Efficient Solution ◽  
Efficient Solutions ◽  
Affirmative Answer ◽  
P Systems ◽  
Membrane Systems ◽  
Complete Problems ◽  
Np Complete ◽  
Np Problem ◽  
Computing Models

Over the last few years, a new methodology to address the P versus NP problem has been developed, based on searching for borderlines between the nonefficiency of computing models (only problems in class P can be solved in polynomial time) and the presumed efficiency (ability to solve NP-complete problems in polynomial time). These borderlines can be seen as frontiers of efficiency, which are crucial in this methodology. “Translating,” in some sense, an efficient solution in a presumably efficient model to an efficient solution in a nonefficient model would give an affirmative answer to problem P versus NP. In the framework of Membrane Computing, the key of this approach is to detect the syntactic or semantic ingredients that are needed to pass from a nonefficient class of membrane systems to a presumably efficient one. This paper deals with tissue P systems with communication rules of type symport/antiport allowing the evolution of the objects triggering the rules. In previous works, frontiers of efficiency were found in these kinds of membrane systems both with division rules and with separation rules. However, since they were not optimal, it is interesting to refine these frontiers. In this work, optimal frontiers of the efficiency are obtained in terms of the total number of objects involved in the communication rules used for that kind of membrane systems. These optimizations could be easier to translate, if possible, to efficient solutions in a nonefficient model.

scholarly journals Training Hungarian neonatal transport nurses in screening for retinopathy of prematurity with telemedicine

2019 ◽  
Vol 2 (3) ◽  
pp. 65-71
Author(s):  
Zs Somogyvári ◽  
E Maka ◽  
J Németh ◽  
ZZ Nagy
Keyword(s):  
Retinopathy Of Prematurity ◽  
Selection Process ◽  
Theory And Practice ◽  
University Hospital ◽  
Wide Field ◽  
Artificial Eye ◽  
Neonatal Transport ◽  
Video Recordings ◽  
To Receive ◽  
Different Levels

Purpose Remote screening for retinopathy of prematurity by wide-field digital imaging and network telemedicine is increasingly used to prevent blindness without the unnecessary transport of infants. Our purpose was to train and license dedicated neonatal transport nurses to do this in Hungary. Materials and methods We developed a complex, four-step curriculum in mobile retinotelemetry. Using a robust selection process, we invited eight transport nurses (NtNP/RtN) to receive training during the 2008–2017 project. The curriculum started with the basics of ophthalmology. Using an artificial eye, it continued with the theory and practice of ophthalmologic exams. Then, supervised by an ophthalmologist, each nurse performed 50 video recordings of anaesthetized and non-anaesthetized infants. Results After demonstrating their competence, five of the eight candidate nurses received a license for retinotelemetry. During their subsequent practice, they had to undergo case reviews half-yearly by a specialist and renew their license every 2–3 years. During the 2008–2016 period, we analysed 7,177 remote screenings from a training perspective. During January 1–August 31 in 2017 period, we analysed extra data from 795 remote screenings of 332 infants from specific prevention perspectives. Conclusions With the cooperation of preexisting neonatal transport service and the ophthalmological reading centre of a university hospital, a mobile telemedicine screening network was successfully developed in Hungary. Our results demonstrate how retinotelemetry can support different levels of prevention medicine. The network should work effectively and efficiently with continuous professional development.

scholarly journals Saccade target selection in macaque during feature and conjunction visual search

1999 ◽  
Vol 16 (1) ◽  
pp. 81-89 ◽  
Author(s):  
NARCISSE P. BICHOT ◽  
JEFFREY D. SCHALL
Keyword(s):  
Visual Search ◽  
Computational Models ◽  
Selection Process ◽  
Target Selection ◽  
Conjunction Search ◽  
Saccade Target ◽  
Experimental Session ◽  
Shape Information ◽  
Feature Search ◽  
The Individual

To gain insight into how vision guides eye movements, monkeys were trained to make a single saccade to a specified target stimulus during feature and conjunction search with stimuli discriminated by color and shape. Monkeys performed both tasks at levels well above chance. The latencies of saccades to the target in conjunction search exhibited shallow positive slopes as a function of set size, comparable to slopes of reaction time of humans during target present/absent judgments, but significantly different than the slopes in feature search. Properties of the selection process were revealed by the occasional saccades to distractors. During feature search, errant saccades were directed more often to a distractor near the target than to a distractor at any other location. In contrast, during conjunction search, saccades to distractors were guided more by similarity than proximity to the target; monkeys were significantly more likely to shift gaze to a distractor that had one of the target features than to a distractor that had none. Overall, color and shape information were used to similar degrees in the search for the conjunction target. However, in single sessions we observed an increased tendency of saccades to a distractor that had been the target in the previous experimental session. The establishment of this tendency across sessions at least a day apart and its persistence throughout a session distinguish this phenomenon from the short-term (<10 trials) perceptual priming observed in this and earlier studies using feature visual search. Our findings support the hypothesis that the target in at least some conjunction visual searches can be detected efficiently based on visual similarity, most likely through parallel processing of the individual features that define the stimuli. These observations guide the interpretation of neurophysiological data and constrain the development of computational models.

The functional determinants in the organization of bacterial genomes

2020 ◽  
Author(s):  
Zhaoqian Liu ◽  
Jingtong Feng ◽  
Bin Yu ◽  
Qin Ma ◽  
Bingqiang Liu
Keyword(s):  
Computational Models ◽  
Bacterial Genomes ◽  
Cellular Processes ◽  
Local Structures ◽  
Disease Mechanisms ◽  
Challenges And Opportunities ◽  
Genomic Studies ◽  
Primary Focus ◽  
Organizational Mechanisms ◽  
Transcription And Replication

Abstract Bacterial genomes are now recognized as interacting intimately with cellular processes. Uncovering organizational mechanisms of bacterial genomes has been a primary focus of researchers to reveal the potential cellular activities. The advances in both experimental techniques and computational models provide a tremendous opportunity for understanding these mechanisms, and various studies have been proposed to explore the organization rules of bacterial genomes associated with functions recently. This review focuses mainly on the principles that shape the organization of bacterial genomes, both locally and globally. We first illustrate local structures as operons/transcription units for facilitating co-transcription and horizontal transfer of genes. We then clarify the constraints that globally shape bacterial genomes, such as metabolism, transcription and replication. Finally, we highlight challenges and opportunities to advance bacterial genomic studies and provide application perspectives of genome organization, including pathway hole assignment and genome assembly and understanding disease mechanisms.

scholarly journals Comparing Individual-Based Approaches to Modelling the Self-Organization of Multicellular Tissues

2016 ◽  
Author(s):  
James M. Osborne ◽  
Alexander G. Fletcher ◽  
Joseph M. Pitt-Francis ◽  
Philip K. Maini ◽  
David J. Gavaghan
Keyword(s):  
Case Studies ◽  
Computational Models ◽  
Experimental Studies ◽  
Computational Modelling ◽  
Tissue Growth ◽  
Self Organization ◽  
Final Approval ◽  
Computational Framework ◽  
Cellular Processes ◽  
Modelling Approaches

AbstractThe coordinated behaviour of populations of cells plays a central role in tissue growth and renewal. Cells react to their microenvironment by modulating processes such as movement, growth and proliferation, and signalling. Alongside experimental studies, computational models offer a useful means by which to investigate these processes. To this end a variety of cell-based modelling approaches have been developed, ranging from lattice-based cellular automata to lattice-free models that treat cells as point-like particles or extended shapes. It is difficult to accurately compare between different modelling approaches, since one cannot distinguish between differences in behaviour due to the underlying model assumptions and those due to differences in the numerical implementation of the model. Here, we exploit the availability of an implementation of five popular cell-based modelling approaches within a consistent computational framework, Chaste (http://www.cs.ox.ac.uk/chaste). This framework allows one to easily change constitutive assumptions within these models. In each case we provide full details of all technical aspects of our model implementations. We compare model implementations using four case studies, chosen to reflect the key cellular processes of proliferation, adhesion, and short-and long-range signalling. These case studies demonstrate the applicability of each model and provide a guide for model usage.Authors’ contributionsJO and AF conceived of the study, designed the study, coordinated the study, carried out the computational modelling and drafted the manuscript. JP contributed to the computational modelling and helped draft the manuscript. PM and DG conceived of the study, designed the study and helped draft the manuscript. All authors gave final approval for publication.

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