Typically, the search for solutions in discrete optimization problems is associated with fundamental computational difficulties. The known methods of accurate or approximated solution of such problems are studied talking into consideration their belonging to so-called problems from P and NP class (algorithms for polynomial and exponential implementation of solution). Modern combinatorial methods for practical solution of discrete optimization problems are focused on the development of algorithms which allow obtaining an approximated solution with guaranteed evaluation of deviations from the optimum. Simplification algorithms are an effective technique of the search for solutions to an optimization problem. If we make a projection of a multi-dimensional process onto a two-dimensional plane, this technique will make it possible to clearly display a set of all solutions to the problem in graphical form. The method for simplification of the combinatorial solution to the discrete optimization problem was proposed in the framework of this research. It is based on performance of decomposition of a system that reflects the system of constraints of the original five-dimensional original problem on a two-dimensional plane. This method enables obtaining a simple system of graphic solutions to a complex problem of linear discrete optimization. From the practical point of view, the proposed method enables us to simplify computational complexity of optimization problems of such a class. The applied aspect of the proposed approach is the use of obtained scientific results in order to provide a possibility to improve the typical technological processes, described by systems of linear equations with existence of systems of linear constraints. This is a prerequisite for subsequent development and improvement of similar systems. In this study, the technique for decomposition of a discrete optimization system through projection of an original problem on two-dimensional coordinate planes was proposed. In this case, the original problem is transformed to a combinatorial family of subsystems, which makes it possible to obtain a system of graphic solutions to a complex problem of linear discrete optimization.

/pdf/algorithm-for-the-simplification-of-solution-to-discrete-440znbuipg.pdf

Algorithm for the simplification of solution to discrete optimization problems

The Bitcoin cryptocurrency is a worldwide prevalent virtualized digital currency conceptualized in 2008 as a distributed transactions system. Bitcoin transactions make use of peer-to-peer network nodes without a third-party intermediary, and the transactions can be verified by the node. Although Bitcoin networks have exhibited high efficiency in the financial transaction systems, their payment transactions are vulnerable to several ransomware attacks. For that reason, investigators have been working on developing ransomware payment identification techniques for bitcoin transactions’ networks to prevent such harmful cyberattacks. In this paper, we propose a high performance Bitcoin transaction predictive system that investigates the Bitcoin payment transactions to learn data patterns that can recognize and classify ransomware payments for heterogeneous bitcoin networks. Specifically, our system makes use of two supervised machine learning methods to learn the distinguishing patterns in Bitcoin payment transactions, namely, shallow neural networks (SNN) and optimizable decision trees (ODT). To validate the effectiveness of our solution approach, we evaluate our machine learning based predictive models on a recent Bitcoin transactions dataset in terms of classification accuracy as a key performance indicator and other key evaluation metrics such as the confusion matrix, positive predictive value, true positive rate, and the corresponding prediction errors. As a result, our superlative experimental result was registered to the model-based decision trees scoring 99.9% and 99.4% classification detection (two-class classifier) and accuracy (multiclass classifier), respectively. Hence, the obtained model accuracy results are superior as they surpassed many state-of-the-art models developed to identify ransomware payments in bitcoin transactions.

High Performance Classification Model to Identify Ransomware Payments for Heterogeneous Bitcoin Networks

We propose the method for the evaluation of results of scientific research activity of scientists PR-q. This method allows us to calculate a scalar evaluation of the results of scientific activity. The method is based on determining a number of real coefficients, which determine citation of one scientist in the publications by other scientists. The basis of the method is finding the evaluations by solving a system of linear algebraic equations. In this case, the matrix of the given system consists of the constructed coefficients. The proposed method, in contrast to other known methods of calculating the indices of citation, does not lose information about any citation of the author and of any publication. We proposed the method, based on the construction of vectors of scalar evaluations for each scientist in a multidimensional metric space. This method implies construction of the ideal point, which consists of scalar evaluations, the best in terms of achieving maximal effectiveness of scientific research activity. The evaluation of each scientist is calculated as a metric distance from the ideal point to the vector of scalar evaluations of the given scientist. The proposed methods for the evaluation of results of scientific research activity might be used to build the modules for automated systems of evaluation of the results of the work of scientists, effectiveness of conducting scientific research by higher educational institutions

http://journals.uran.ua/eejet/article/download/103651/100847

Evaluation methods of the results of scientific research activity of scientists based on the analysis of publication citations

World practice to overcome the lack of knowledge and meet educational needs under the terms of career growth and personal improvement and development is based on the modern paradigm of continuous postgraduate education ‑ lifelong learning (LLL). In the context of learning management, the analysis of features and synthesis of the structure of interaction of the basic process entities as knowledge holders were performed. Referring basic knowledge holders ‑ team, customer, training and in-depth knowledge systems to certain discrete states, which the system may take, allows representing the system using a Markov chain with four discrete states. A directed graph of the Markov chain reflects the secondary projection of a communication on the knowledge space rather than the physical interaction of the knowledge holders. Markov chain transition probabilities for the project environment define its characteristics that vary in discrete time by the steps in the form of a set of state probabilities. Cognitive properties of the model which is based on the Markov chain makes it possible to set some specific values of the transition probabilities of the system. The results obtained are the justification for continuing training and acquiring additional education of personnel in the deficit of knowledge that is necessary for the implementation of unique projects. Using the developed cognitive model of the interaction of knowledge in project management, the paradigm of “lifelong learning” was justified. The knowledge management structure includes four fundamental entities: the customer, the team, training and in-depth knowledge systems of the knowledge owners. These entities are in a constant process of knowledge sharing. The systems of training and in-depth knowledge play a role of generating new knowledge, which was absent in the project environment. Continuing education ideally is aimed at balancing between the needs of society and the motivational structure of personality that actually should be implemented through the mechanisms of the influence of education on the socialization of the individual.

http://journals.uran.ua/eejet/article/download/74905/72167

Lifelong learning” is a new paradigm of personnel training in enterprises

This study has improved the standard P5 (Personnel, planet, profit, process, product), which has already been widely applied globally in the practice of project management. However, the standard P5 provides a scheme of the life cycle of projects’ benefits, which makes it possible to represent the lifecycle processes only at the qualitative level. In order to pass to the quantitative estimates, it has been proposed to apply the Markovian chain that maps a phenomenological representation of complex systems without considering their physical character. We have constructed a cognitive Markovian model of the life cycle of a project’s benefits using the communications between the states of the project system. The cognitive structure of the life cycle is similar to a directed graph where vertices indicate the state of the system, and links are the communications between them. We have proposed an approach to determining transitional probabilities based on the evaluation of communications, taking into consideration the time costs to perform operations in the form of rules. The character of communications between states s→j in the Markovian chain defines the magnitude of transition probabilities π sj . The time costs required for each state are divided into five intervals π sj : {0} – no costs; {0.01–0.1} – insignificant time costs; {0.1–0.3} – the lowest level of time costs; {0.3–0.7} – average time costs; {0.7–1.0} – the largest time costs. The logic of choosing values for conditional transition probabilities in the Markovian chain makes it possible to determine data for the simulation of the trajectory of the life cycle of projects’ benefits in the coordinates of the probabilities of states of the system and steps. It has been shown that the application of the Markovian chains is rational in order to represent the life cycle of projects’ benefits. An analysis was performed to determine a certain level of technological maturity of the project environment (organization), which corresponds to the totality of values for transition probabilities. We have studied the influence of the level of technological maturity of the project environment (organization) on the projects’ efficiency. Another example of the implementation of the project aimed at forming the positive image of an educational establishment by applying the frontal information communication via television, the press, by taking part in mass political activities, has also revealed positive estimation. The probability distribution at the beginning of the project (V1) and upon its completion (V2) differs significantly. The implementation of the project increased the magnitudes of probabilities of states p7 (Benefit) and p8 (Additional benefit). At the beginning of the project: р7 (V1) +р8 (V2) =0.14+0.05=0.19. Upon implementation of the project: р7 (V1) +р8 (V2) =0.22+0.08=0.30. The evaluation of this project aimed at positive image formation of an educational establishment showed that the results obtained do not contradict the hypothesis about the possibility of applying the Markovian chains to determine the characteristics of the life cycle of a project’s benefits

/pdf/development-of-the-markovian-model-for-the-life-cycle-of-a-1to67kssfw.pdf

Development of the Markovian model for the life cycle of a project’s benefits

According to the basic principle of self-developing systems, the interaction parameters of two opposing tendencies of the system operation can be distinguished – the conservative tendency and the changing tendency. It explains the balance of the two activity tendencies of team members – the ability to conserve and the ability to change. On the basis of the Belbin’s model, each participant’s role structure is determined by means of which the participants’ activity tendencies are determined with use of Lotka, Volterra and Gause’s self-developing systems. This system is considered according to the types of interactions such as “cooperation” and “competition”. The equilibrium point of role activity trends is determinedto have the most minimal impact that determines the subsequent state of the system maximally. It is shown that the role differentiation of the effective team does not always depend on the number of participants. Each participant may combine the multiple roles that can lead to the balance of conservative and changing tendencies. It defines the conditions of effective work in operational and development in management of project operation and development.

/pdf/the-research-on-role-differentiation-as-a-method-of-forming-5a69ok2eex.pdf

The research on role differentiation as a method of forming the project team

The world experience of solving the problems of project management is generally directed to the use of the best practices. But conditions for the improvement and development of organizational structures in management of organizations and enterprises are not always created. In this study, in the context of project management theory, the structure of communication between the main entities of the process: the team, the project and its environment was generalized. The assignment of these components of the project environment to specific discrete states, in which the project system may be, enables to display the system using a Markov chain with three discrete states. The transition probabilities of the Markov chain for the project environment determine its characteristics which vary in discrete time step by step in the form of a certain set of state probabilities. Cognitive features of the model which was built on the basis of a Markov chain allows to assign specific values to the transition probabilities of the system. In this paper, a new approach for determining the values of the transition probabilities is proposed. The transition probabilities are identified with the relative time of resource cost in each of the discrete states. Using the cognitive model that was created by the interaction of the main entities of the project, namely, the team, the project and its environment, the trajectory of the projects development in the case of loyal cooperation and in the case of resistance of the project environment was studied. The received results reflect a strong growth trend of the time resource cost for system interaction with the environment of the project, which eventually will delay the implementation of the project. The obtained results do not contradict the definition of the law of S. D. Bushuev. The structure of the project management in the stage of initiation of the project includes the team, the project and environment of the project. These entities are constantly interacting with each other. The change of the state probabilities of the project fully reflects the progress and impact of the project. This new understanding of the project systems leads us to the development of modern approaches as the basis for new practices in project management.

http://journals.uran.ua/eejet/article/download/80769/77178

Kateryna Kolesnikova

Papers

Algorithm for the simplification of solution to discrete optimization problems

Lifelong learning” is a new paradigm of personnel training in enterprises

Development of the Markovian model for the life cycle of a project’s benefits

The research on role differentiation as a method of forming the project team

Development of the model of interaction among the project, team of project and project environment in project system