9,883 research outputs found

    Метод синтезу моделей станів об’єктів програмного забезпечення автоматизованої системи обробки цифрових зображень

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    This article proposes a method for the synthesis of the behavior of software objects models (SOM) for the developed object-oriented software systems for automated digital image processing in order to avoid systemic and algorithmic errors in the design phase of a software system, as well as to reduce the time of its development. The process of constructing the SOM proceeding from its finite-state representation is viewed from the standpoint of abstract synthesis of an automata’s finite state. Thus, the specialties of the synthesis of finite automaton SOM, the construction of the map defining a plurality of channels management class of objects, the order to bring it to an automata, the construction of the canonical set of events and their regular expressions to display defining a plurality of channels management of software objects class for object oriented software system are considered and justified. Переважна більшість даних, які обробляються сучасними інфокомунікаційними системами, є графічними. Істотна частка з них – цифрові зображення, які характеризуються великими обсягами. Таким чином, виникає потреба їх представлення у компактному вигляді, що забезпечить зменшення навантаження на канали зв’язку, підвищення оперативності доставки та скорочення обсягів пам’яті, необхідної для зберігання даних. Вирішенням цієї проблеми є розроблення з використанням об’єктно- орієнтованої технології автоматизованої системи обробки цифрових зображень (АСОЗ), на етапі проектування якої постає актуальна задача побудови моделей поведінки екземплярів класів об’єктно- орієнтованого програмного забезпечення (ООПЗ) задля уникнення системних та алгоритмічних помилок, а також скорочення часу розроблення. Тож, мета роботи полягає в розробленні метода синтезу моделей станів програмних об’єктів об’єктно-орієнтованого програмного забезпечення АСОЗ. Процес побудови моделі станів програмних об’єктів (МСО) ООПЗ, виходячи з її скінченно- автоматного представлення, розглянуто з погляду абстрактного синтезу скінченного автомата. У роботі викладені й обґрунтовані особливості синтезу скінченно-автоматної МСО ООПЗ, побудова відображення, яке визначає множину каналів керування класу об’єктів, та порядок приведення його до автоматного виду, а також побудова канонічної множини подій і їх регулярних виразів для відображення, яке визначає множину каналів керування класу програмних об’єктів. На основі отриманих результатів дослідження запропоновано метод синтезу моделей станів програмних об’єктів ООПЗ. Запропонований метод забезпечує формалізацію процесу визначення станів та їх взаємозв’язків у життєвому циклі екземпляра класу ООПЗ, а також дозволяє зменшити трудомісткість процесу розробки динамічної компоненти комплексної моделі ООПЗ під час її проектування на логічному рівні

    Modelling microstructure evolution during equal channel angular pressing of magnesium alloys using cellular automata finite element method

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    Equal channel angular pressing (ECAP) is one of the most popular methods of obtaining ultrafine grained (UFG) metals. However, only relatively short billets can be processed by ECAP due to force limitation. A solution to this problem could be recently developed incremental variant of the process, so called I-ECAP. Since I-ECAP can deal with continuous billets, it can be widely used in industrial practice. Recently, many researchers have put an effort to obtain UFG magnesium alloys which, due to their low density, are very promising materials for weight and energy saving applications. It was reported that microstructure refinement during ECAP is controlled by dynamic recrystallization and the final mean grain size is dependent mainly on processing temperature. In this work, cellular automata finite element (CAFE) method was used to investigate microstructure evolution during four passes of ECAP and its incremental variant I-ECAP. The cellular automata space dynamics is determined by transition rules, whose parameters are strain, strain rate and temperature obtained from FE simulation. An internal state variable model describes total dislocation density evolution and transfers this information to the CA space. The developed CAFE model calculates the mean grain size and generates a digital microstructure prediction after processing, which could be useful to estimate mechanical properties of the produced UFG metal. Fitting and verification of the model was done using the experimental results obtained from I-ECAP of an AZ31B magnesium alloy and the data derived from literature. The CAFE simulation results were verified for the temperature range 200-250 °C and strain rate 0.01-0.5 s-1; good agreement with experimental data was achieved

    radiomic features for medical images tamper detection by equivalence checking

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    Abstract Digital medical images are very easy to be modified for illegal purposes. An attacker may perform this act in order to stop a political candidate, sabotage research, commit insurance fraud, perform an act of terrorism, or even commit murder. Between the machine that performs medical scans and the radiologist monitor, medical images pass through different devices: in this chain an attacker can perform its malicious action. In this paper we propose a method aimed to avoid medical images modifications by means of equivalence checking. Magnetic images are represented as finite state automata and equivalence checking is exploited to check whether the medical resource have been subject to illegal modifications

    Broadcasting Automata and Patterns on Z^2

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    The Broadcasting Automata model draws inspiration from a variety of sources such as Ad-Hoc radio networks, cellular automata, neighbourhood se- quences and nature, employing many of the same pattern forming methods that can be seen in the superposition of waves and resonance. Algorithms for broad- casting automata model are in the same vain as those encountered in distributed algorithms using a simple notion of waves, messages passed from automata to au- tomata throughout the topology, to construct computations. The waves generated by activating processes in a digital environment can be used for designing a vari- ety of wave algorithms. In this chapter we aim to study the geometrical shapes of informational waves on integer grid generated in broadcasting automata model as well as their potential use for metric approximation in a discrete space. An explo- ration of the ability to vary the broadcasting radius of each node leads to results of categorisations of digital discs, their form, composition, encodings and gener- ation. Results pertaining to the nodal patterns generated by arbitrary transmission radii on the plane are explored with a connection to broadcasting sequences and ap- proximation of discrete metrics of which results are given for the approximation of astroids, a previously unachievable concave metric, through a novel application of the aggregation of waves via a number of explored functions

    On the Algorithmic Nature of the World

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    We propose a test based on the theory of algorithmic complexity and an experimental evaluation of Levin's universal distribution to identify evidence in support of or in contravention of the claim that the world is algorithmic in nature. To this end we have undertaken a statistical comparison of the frequency distributions of data from physical sources on the one hand--repositories of information such as images, data stored in a hard drive, computer programs and DNA sequences--and the frequency distributions generated by purely algorithmic means on the other--by running abstract computing devices such as Turing machines, cellular automata and Post Tag systems. Statistical correlations were found and their significance measured.Comment: Book chapter in Gordana Dodig-Crnkovic and Mark Burgin (eds.) Information and Computation by World Scientific, 2010. (http://www.idt.mdh.se/ECAP-2005/INFOCOMPBOOK/). Paper website: http://www.mathrix.org/experimentalAIT

    What is known about the Value 1 Problem for Probabilistic Automata?

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    The value 1 problem is a decision problem for probabilistic automata over finite words: are there words accepted by the automaton with arbitrarily high probability? Although undecidable, this problem attracted a lot of attention over the last few years. The aim of this paper is to review and relate the results pertaining to the value 1 problem. In particular, several algorithms have been proposed to partially solve this problem. We show the relations between them, leading to the following conclusion: the Markov Monoid Algorithm is the most correct algorithm known to (partially) solve the value 1 problem
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