Finite Automata and Unions of Regular Patterns with Bounded Constant Segments

Each molecule of ferritin (d = 130Å) contains a core of iron surrounded by a 24-subunit protein shell. The amount of iron stored is variable and is present within the central cavity (d = 80Å) as a hydrated ferric oxide equivalent to the mineral, ferrihydrite. Many early ultrastructural studies of ferritin detected regular patterns of a multiparticulate substructure in the iron-rich core [e.g., 3,4], Each small particle was termed a “micelle“; a theory became widely accepted that a core consisted of up to six micelles positioned at the vertices of an octahedron. Other workers recognized that the apparent micelles were smaller or even disappeared if images were recorded closer to exact focus [e.g., 5]. In 1969, Haydon clearly established that the observed substructure was really an imaging artifact; each apparent micelle was only a dot in the underfocused phase contrast image of the supporting film superimposed on the amplitude image of the strongly scattering metal.

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The buckling of thin EM specimens

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177386 ◽

1990 ◽

Vol 48 (4) ◽

pp. 850-851

Author(s):

A.R. Thölén

Keyword(s):

Electron Microscope ◽

Elastic Properties ◽

Crystal Surface ◽

Specimen Surface ◽

Radius Of Curvature ◽

Thin Foils ◽

Thin Electron ◽

Regular Patterns

Thin electron microscope specimens often contain irregular bend contours (Figs. 1-3). Very regular bend patterns have, however, been observed around holes in some ion-milled specimens. The purpose of this investigation is twofold. Firstly, to find the geometry of bent specimens and the elastic properties of extremely thin foils and secondly, to obtain more information about the background to the observed regular patterns.The specimen surface is described by z = f(x,y,p), where p is a parameter, eg. the radius of curvature of a sphere. The beam is entering along the z—direction, which coincides with the foil normal, FN, of the undisturbed crystal surface (z = 0). We have here used FN = [001]. Furthermore some low indexed reflections are chosen around the pole FN and in our fcc crystal the following g-vectors are selected:

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A novel cryptosystem based on abstract automata and Latin cubes

Studia Scientiarum Mathematicarum Hungarica ◽

10.1556/012.2015.52.2.1309 ◽

2015 ◽

Vol 52 (2) ◽

pp. 221-232

Author(s):

Pál Dömösi ◽

Géza Horváth

Keyword(s):

Block Cipher ◽

Finite Automata ◽

Theoretical Background ◽

Point Of View ◽

Theoretical Point ◽

Transition Matrices ◽

Encryption And Decryption ◽

Secret Keys ◽

Automata Network ◽

Fully Functioning

In this paper we introduce a novel block cipher based on the composition of abstract finite automata and Latin cubes. For information encryption and decryption the apparatus uses the same secret keys, which consist of key-automata based on composition of abstract finite automata such that the transition matrices of the component automata form Latin cubes. The aim of the paper is to show the essence of our algorithms not only for specialists working in compositions of abstract automata but also for all researchers interested in cryptosystems. Therefore, automata theoretical background of our results is not emphasized. The introduced cryptosystem is important also from a theoretical point of view, because it is the first fully functioning block cipher based on automata network.

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Parallel Combining Different Approaches to Multi-pattern Matching for Fpga-based Security Systems

Advances in Cyber-Physical Systems ◽

10.23939/acps2020.01.008 ◽

2017 ◽

Vol 5 (1) ◽

pp. 8-15

Author(s):

Sergii Hilgurt ◽

Keyword(s):

Information Security ◽

Pattern Matching ◽

Intrusion Detection System ◽

Detection System ◽

Finite Automata ◽

Network Intrusion Detection ◽

Security Systems ◽

Analytical Technique ◽

Network Intrusion ◽

Pros And Cons

The multi-pattern matching is a fundamental technique found in applications like a network intrusion detection system, anti-virus, anti-worms and other signature- based information security tools. Due to rising traffic rates, increasing number and sophistication of attacks and the collapse of Moore’s law, traditional software solutions can no longer keep up. Therefore, hardware approaches are frequently being used by developers to accelerate pattern matching. Reconfigurable FPGA-based devices, providing the flexibility of software and the near-ASIC performance, have become increasingly popular for this purpose. Hence, increasing the efficiency of reconfigurable information security tools is a scientific issue now. Many different approaches to constructing hardware matching circuits on FPGAs are known. The most widely used of them are based on discrete comparators, hash-functions and finite automata. Each approach possesses its own pros and cons. None of them still became the leading one. In this paper, a method to combine several different approaches to enforce their advantages has been developed. An analytical technique to quickly advance estimate the resource costs of each matching scheme without need to compile FPGA project has been proposed. It allows to apply optimization procedures to near-optimally split the set of pattern between different approaches in acceptable time.

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Complexity and Universality of Iterated Finite Automata

Complex Systems ◽

10.25088/complexsystems.18.1.145 ◽

2009 ◽

Vol 18 (1) ◽

pp. 145-158

Author(s):

Jiang Zhang ◽

Keyword(s):

Finite Automata

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Circulant Singular Spectrum Analysis to Monitor the State of the Economy in Real Time

Mathematics ◽

10.3390/math9111169 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1169

Author(s):

Juan Bógalo ◽

Pilar Poncela ◽

Eva Senra

Keyword(s):

Business Cycles ◽

Real Time ◽

Parametric Method ◽

Singular Spectrum Analysis ◽

The State ◽

Signal Extraction ◽

Alternative Procedure ◽

State Of The Economy ◽

Regular Patterns ◽

Non Parametric

Real-time monitoring of the economy is based on activity indicators that show regular patterns such as trends, seasonality and business cycles. However, parametric and non-parametric methods for signal extraction produce revisions at the end of the sample, and the arrival of new data makes it difficult to assess the state of the economy. In this paper, we compare two signal extraction procedures: Circulant Singular Spectral Analysis, CiSSA, a non-parametric technique in which we can extract components associated with desired frequencies, and a parametric method based on ARIMA modelling. Through a set of simulations, we show that the magnitude of the revisions produced by CiSSA converges to zero quicker, and it is smaller than that of the alternative procedure.

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