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Highly efficient scheduling algorithms for identical parallel machines with sufficient conditions for optimality of the solutions

Telenyk Sergii, Nowakowski Grzegorz, Pavlov Oleksandr, Misura Olena, Melnikov Oleg, Khalus Olena

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 1

art. no. e148939

EN

This paper aims to develop new highly efficient PSC-algorithms (algorithms that contain a polynomial-time sub-algorithm with sufficient conditions for the optimality of the solutions obtained) for several interrelated problems involving identical parallel machine scheduling. These problems share common basic theoretical positions and common principles of their solving. Two main intractable scheduling problems are considered: (“Minimization of the total tardiness of jobs on parallel machines with machine release times and a common due date” (TTPR) and “Minimising the total tardiness of parallel machines completion times with respect to the common due date with machine release times” (TTCR)) and an auxiliary one (“Minimising the difference between the maximal and the minimal completion times of the machines” (MDMM)). The latter is used to efficiently solve the first two ones. For the TTPR problem and its generalisation in the case when there are machines with release times that extend past the common due date (TTPRE problem), new theoretical properties are given, which were obtained on the basis of the previously published ones. Based on the new theoretical results and computational experiments the PSC-algorithm solving these two problems is modified (sub-algorithms A1, A2). Then the auxiliary problem MDMM is considered and Algorithm A0 is proposed for its solving. Based on the analysis of computational experiments, A0 is included in the PSC-algorithm for solving the problems TTPR, TTPRE as its polynomial component for constructing a schedule with zero tardiness of jobs if such a schedule exists (a new third sufficient condition of optimality). Next, the second intractable combinatorial optimization problem TTCR is considered, deducing its sufficient conditions of optimality, and it is shown that Algorithm A0 is also an efficient polynomial component of the PSC-algorithm solving the TTCR problem. Next, the case of a schedule structure is analysed (partially tardy), in which the functionals of the TTPR and TTCR problems become identical. This facilitates the use of Algorithm A1 for the TTPR problem in this case of the TTCR problem. For Algorithm A1, in addition to the possibility of obtaining a better solution, there exists a theoretically proven estimate of the deviation of the solution from the optimum. Thus, the second PSC-algorithm solving the TTCR problem finds an exact solution or an approximate solution with a strict upper bound for its deviation from the optimum. The practicability of solving the problems under consideration is substantiated.

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An analysis of the influence of famous people’s posts on social networks on the cryptocurrency exchange rate

Telenyk Sergii, Nowakowski Grzegorz, Gavrilenko Olena, Miahkyi Mykhailo, Khalus Olena

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2024

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Vol. 72, nr 4

art. no. e150117

EN

In this work, the level of influence of the posts published by famous people on social networks on the formation of the cryptocurrency exchange rate is investigated. Celebrities who are familiar with the financial industry, especially with the cryptocurrency market, or are somehow connected to a certain cryptocurrency, such as Elon Musk with Dogecoin, are chosen as experts whose influence through social media posts on cryptocurrency rates is examined. This research is conducted based on statistical analysis. Real cryptocurrency exchange rate forecasts for the selected time period and predicted ones for the same period, obtained using three algorithms, are utilized as a dataset. This paper uses methods such as statistical hypotheses regarding the significance of Spearman’s rank correlation coefficient and Pearson’s correlation. It is confirmed that the posts by famous people on social networks significantly affect the exchange rates of cryptocurrencies.

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Simple and flexible way to integrate heterogeneous information systems and their services into the world data system

Nowakowski Grzegorz, Telenyk Sergii, Yefremov Kostiantyn, Khmeliuk Volodymyr

Journal of Automation Mobile Robotics and Intelligent Systems

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2021

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Vol. 15, No. 4

76--90

EN

The approach to applications integration for World Data Center (WDC) interdisciplinary scientific investigations is developed in the article. The integration is based on mathematical logic and artificial intelligence. Key elements of the approach – a multilevel system architecture, formal logical system, implementation – are based on intelligent agents interaction. The formal logical system is proposed. The inference method and mechanism of solution tree recovery are elaborated. The implementation of application integration for interdisciplinary scientific research is based on a stack of modern protocols, enabling communication of business processes over the transport layer of the OSI model. Application integration is also based on coordinated models of business processes, for which an integrated set of business applications are designed and realized.

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Non-contact video-based remote photoplethysmography for human stress detection

Nikolaiev Sergii, Telenyk Sergii, Tymoshenko Yury

Journal of Automation Mobile Robotics and Intelligent Systems

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2020

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Vol. 14, No. 2

63--73

EN

This paper presents the experimental results for stress index calculation using developed by the authors information technology for non-contact remote human heart rate variability (HRV) retrieval in various conditions from video stream using common wide spread web cameras with minimal frame resolution of 640x480 pixels at average frame rate of 25 frames per second. The developed system architecture based on remote photoplethysmography (rPPG) technology is overviewed including description of all its main components and processes involved in converting video stream of frames into valuable rPPG signal. Also, algorithm of RR-peaks detection and RR-intervals retrieval is described. It is capable to detect 99.3% of heart contractions from raw rPPG signal. The usecases of measuring stress index in a wide variety of situations starting with car and tractor drivers at work research and finishing with students passing exams are presented and analyzed in detail. The results of the experiments have shown that the rPPG system is capable of retrieving stress level that is in accordance with the feelings of experiments’ participants.

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The approach to applications integration for world data center interdisciplinary scientific investigations

Nowakowski Grzegorz, Telenyk Sergii, Yefremov Kostiantyn, Khmeliuk Volodymyr

Annals of Computer Science and Information Systems

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2019

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Vol. 18

539--545

EN

The approach to applications integration for World Data Center (WDC) interdisciplinary scientific investigations is developed in the article. The integration is based on mathematical logic and artificial intelligence. Key elements of the approach - a multilevel system architecture, formal logical system, implementation - are based on intelligent agents interaction. The formal logical system is proposed. The inference method and mechanism of solution tree recovery are elaborated. The implementation of application integration for interdisciplinary scientific research is based on a stack of modern protocols, enabling communication of business processes over the transport layer of the OSI model. Application integration is also based on coordinated models of business processes, for which an integrated set of business applications are designed and realized.