Breaking an image encryption algorithm based on chaos

Recently, a chaos-based image encryption algorithm called MCKBA (Modified Chaotic-Key Based Algorithm) was proposed. This paper analyzes the security of MCKBA and finds that it can be broken with a differential attack, which requires only four chosen plain-images. Performance of the attack is verified by experimental results. In addition, some defects of MCKBA, including insensitivity with respect to changes of plain-image/secret key, are reported.Comment: 10 pages, 4 figure

Technology for the Identification of Suspicious Contracts Involving Sustainable Groups of Suppliers in Public Procurements

The paper discusses the problems that customers may encounter while conducting public procurement, namely, possible prior collusion between bidders aimed at winning the contract at the highest possible price.The objective of the study is to develop a technology for automated detection of sustainable groups of pipe suppliers in public procurements, and also to develop an algorithm that would allow to identify possible collusion between future procurement participants.Presumed indicators of collusion between suppliers are formulated, a technology for identifying a sustainable supplier group is described, an algorithm to assess the possibility of affiliated suppliers participating in the current tender is developed. Keywords: public procurement, collusion of supplier

Technology for Automated Search and Detection of Overpriced Road Construction and Repair Public Procurement Contracts

The paper presents the results of the use of the technology developed by the authors for automated monitoring of financial and economic events corresponding to formalized typologies of suspicious activity in the area of public procurement developed by the Eurasian Anti-Money-Laundering and Combating Terrorist Financing Group (EAG). For this work, a typology based on deviation of contract price from market price in road construction and maintenance was chosen. Keywords: public procurement, road construction and repair, AML/CFT, suspicious activity, typolog

Deterministic coherence resonance in coupled chaotic oscillators with frequency mismatch

A small mismatch between natural frequencies of unidirectionally coupled chaotic oscillators can induce coherence resonance in the slave oscillator for a certain coupling strength. This surprising phenomenon resembles “stabilization of chaos by chaos,” i.e., the chaotic driving applied to the chaotic system makes its dynamics more regular when the natural frequency of the slave oscillator is a little different than the natural frequency of the master oscillator. The coherence is characterized with the dominant component in the power spectrum of the slave oscillator, normalized standard deviations of both the peak amplitude and the interpeak interval, and Lyapunov exponents. The enhanced coherence is associated with increasing negative both the third and the fourth Lyapunov exponents, while the first and second exponents are always positive and zero, respectively

Early Detection Modelling of Credit Institution License Withdrawal

The paper considers credit organizations as the pivotal elements of the state's economic and financial system. Credit institutions license withdrawal probability is estimated on the basis of binary choice models. A methodology for processing and analyzing credit institutions data based on regression analysis and multi-criteria optimization methods has been developed and used to identify bank groups potentially threatening the stability of the Russian banking system and the integrity of anti-money laundering and terrorist financing system (AML/CFT). Keywords: credit institution license withdrawal, binary choice model, anti-money laundering and terrorist financing

Modeling of Credit Institution License Withdrawal Based on Panel Data

The research paper involves the construction of panel data binary response models to forecast the probability of a credit institution's license withdrawal based on its financial performance, including the construction of logit and probit models using various sets of source data offers a technique for shaping a general model. Keywords: credit institutions, panel data, binary response models, license withdrawa

Recent Advances in Magnetoencephalography

The review of novel advances in the magnetoencephalography (MEG) technique is present, including the development of optically pumped magnetometers (OPM) which are very promising for brain-computer interfaces (BCIs). The main advantage of OPMs over conventional SQUID devices is that they do not require cryogenic cooling, that decreases their price by 2–3 times. Moreover, the OPMs can be placed within millimeters from the scalp, that approximately doubles the signal-to-noise ratio. In addition, they are not so susceptible to muscle artefacts as EEG. In addition, the location of OPMs in a field-nulling apparatus decreases the influence of artefacts caused by head movement in the ambient field. All these advantages give potential possibilities to develop a new generation of OPM-based BCIs, cheaper, more flexible and sensitive than SQUID-based BCIs, which can serve for both motor and non-motor tasks. Despite the enormous progress made in the past few years, OPM–MEG is so far a developing technology that needs further improvement. Due to their large size, the number of channels is relatively small and therefore they cannot cover the entire head. The miniaturization and universality of lightweight helmets would be an essential step towards further development of OPM wearable for BCI applications

Deterministic coherence resonance in a ring of coupled chaotic oscillators

We study synchronization three unidirectionally Rössler oscillator the presence small mismatch between their natural frequencies w1< w2< w3. The forward (1 - 2 - 3 - 1) backward coupling directions are considered. As strength increases, common route to both configurations is intermittent phase imperfect perfect almost synchronization. difference scenario two only occurs couplings regime characterized with time-averaged dominant frequency power spectrum linear approximated slope dependent phases oscillators. Although more easily achieved configuration, results significant enhancement which within narrow range strengths as soon oscillators synchronize phases

An approach to generate deterministic Brownian motion

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A family of multimodal dynamic maps

"We introduce a family of multimodal logistic maps with a single parameter. The maps domain is partitioned in subdomains according to the maximal number of modals to be generated and each subdomain contains one logistic map. The number of members of a family is equal to the maximal number of modals. Bifurcation diagrams and basins of attraction of fixed points are constructed for the family of chaotic logistic maps.