Development of Analytical Methods for Calculating Time Standards for Shunting Operations

Purpose. The article is aimed to conduct a historical analysis of the development of analytical methods for standardizing the duration of shunting operations, as well as assessing their compliance with the existing operating conditions of railway transport. Methodology. The research in this article was carried out on the basis of an analysis of literary sources and methods of the theory of the organization of the operational work of railways. Findings. The standardization of the duration of shunting operations is one of the most important tasks of the theory of operational work of railways. The existing method of standardizing the duration of shunting operations developed in the first half of the 20th century and is used to this day. The performed analysis shows that the scientific principles underlying it generally correspond to the modern conditions of the railway transport. Additional research in this area can be associated with assessing the influence of the initial location of cars on the tracks on the average duration of shunting operations, taking into account the influence of length restrictions of the cars groups being moved, as well as monitoring the implementation of established norms by statistical methods. The article also shows that the values of modern time standards for shunting operations, in many cases, are set for technical means and technologies that were used in railway transport in the 50–70s of the 20th century and do not correspond to the operating conditions of real stations and sidings of industrial enterprises. Therefore, they require revision. Originality. In this paper, based on historical analysis, the process of development of methods for setting the time for shunting operations is described and the factors influencing the current value of norms are established. Practical value. The research results make it possible to identify the reasons for the discrepancy between the existing time standards for performing shunting operations and the real operating conditions of stations and sidings of industrial enterprises, as well as to establish the main elements of the methodology for standardizing the duration of shunting operations that require revision

Use of S. Wright’s path coefficient method for statistical analysis of interrelated traits in rice

S. Wright’s analysis of plant productivity is of great current interest. The research objective was to determine the pair correlation coefficients and S. Wright’s path coefficients for rice varieties and, on their basis, to identify the contribution of each of them to the plant productivity. Ten rice varieties were taken as the test material. The experiments were conducted in the irrigated experimental field of theInstituteofRiceof the National Academy of Agrarian Sciences ofUkrainein 2013, 2014 and 2016. Seeds were sown with an SKS-6A manual seeder; the seeding rate was 7.0 mln germinable seeds per hectare. The predecessor was alfalfa. The plot area was5 m2; the sowing distance was15 cm. The plants were analyzed for the following traits: plant productivity (grain weight), panicle weight, grain weight from side stems, productive tillering capacity, grain number per panicle, spikelet number per panicle, 1000-grain weight, grain weight per panicle, plant height, panicle length and density, empty spikelet number per panicle, and incidence of blind seed disease. Pair correlation coefficients were determined by B.A. Dospekhov’s method; path analysis, by S. Wright’s method. The correlations of productivity with 12 quantitative traits of rice were determined: the correlation was close with the grain weight from side stems and medium with the panicle weight and with the grain weight per panicle. Path analysis of the plant productivity established that the correlations of plant traits with the productivity depended both on direct and indirect effects of each trait on the productivity. The relative contribution of each of the studied 12 traits to the rice productivity was determined; both direct and indirect effects of their interactions with other traits were evaluated. This made it possible to discover causes and consequences of interrelations between the traits and, as a result, to choose valuable-for-selection traits, such as panicle weight and productive tillering capacity, which had the greatest direct effects on the productivity and significant correlations with it

On directed information theory and Granger causality graphs

Directed information theory deals with communication channels with feedback. When applied to networks, a natural extension based on causal conditioning is needed. We show here that measures built from directed information theory in networks can be used to assess Granger causality graphs of stochastic processes. We show that directed information theory includes measures such as the transfer entropy, and that it is the adequate information theoretic framework needed for neuroscience applications, such as connectivity inference problems.Comment: accepted for publications, Journal of Computational Neuroscienc

Інгібітори ацетилхолінестерази з тіазолієвим скафолдом: структурні особливості і способи зв’язування

Aim. To assess the structural features of substituents and the role of a thiazolium scaffold in mechanisms of acetylcholinesterase inhibition by thiazolium salts.Results and discussion. On the basis of activities of model compounds at pH 6.5 and pH 8.0 and the results of molecular docking the binding modes of quaternized derivatives of 5-(2-hydroxyethyl)-4-methylthiazole with different substituents in position 3 and 5 were analyzed. The presence of (N)3-benzyl substituent provides the inhibitor fixation in the catalytic anionic site, whereas acyl fragments of substituents in position 5 are situated in the peripheral anionic site. Logarithms of ІС50 values of the thiazolium inhibitors, except for the compounds containing O-acyl carbocyclic groups, linearly depend on the calculated docking energies in case of a thiazolium, ion as well as a neutral tetrahedral intermediate of the thiazolium ring opening.Experimental part. Thiazolium salts were synthesized by the known methods. The activity of acetylcholinesterase was studied by Ellman’s method. Molecular docking to the active site of acetylcholinesterase was performed using an AutoDock 4.2 program.Conclusions. Structural fragments of substituents in positions 3 and 5 of the heterocyclic scaffold provide binding of the inhibitor in the catalytic anionic site and the peripheral anionic site of acetylcholinesterase, respectively. The heterocyclic scaffold can be bound to the enzyme as a thiazolium ion or a neutral tetrahedralintermediate of the ring opening reaction.Целью работы была оценка структурных особенностей заместителей и роли тиазолиевого скаффолда в механизмах ингибирования ацетилхолинэстеразы солями тиазолия.Результаты и их обсуждение. На основании активности при рН 6,5 и рН 8,0 и согласно результатов молекулярного докинга проанализированы способы связывания ацетилхолинэстеразой кватернизированных производных 5-(2-гидроксиэтил)-4-метилтиазола с различными заместителями в положениях 3 и 5. Наличие (N)3-бензильного заместителя обеспечивает лучшее закрепление ингибитора в каталитическом анионном сайте, тогда как ацильные фрагменты заместителей в положении 5 располагаются в области периферического анионного сайта. Логарифмы значений ІС50, за исключением соединений с О-ацильными карбоциклическими группами, линейно зависят от рассчитанных энергий докинга как в случае тиазолиевого иона, так и в случае нейтрального тетраэдрического интермедиата раскрытия тиазолиевого цикла.Экспериментальная часть. Соли тиазолия синтезированы известными методами. Активность ацетилхолинэстеразы определяли по методу Эллмана. Молекулярный докинг в область активного центра ацетилхолинэстеразы выполнен с использованием программы AutoDock 4.2.Выводы. Структурные фрагменты заместителей в положениях 3 и 5 гетероциклического скаффолда обеспечивают связывание ингибитора в области каталитического и периферического сайтов ацетилхолинэстеразы, соответственно. Гетероциклический скаффолд может быть связан в форме тиазолиевого иона илив форме нейтрального тетраэдрического интермедиата раскрытия тиазолиевого цикла.Метою роботи була оцінка структурних особливостей замісників і ролі тіазолієвого скафолду у механізмах інгібування ацетилхолінестерази солями тіазолію.Результати та їх обговорення. На основі активності при рН 6,5 і рН 8,0 та за результатами молекулярного докінгу проаналізовані способи зв’язування ацетилхолінестеразою кватернізованих похідних 5-(2-гідроксіетил)-4-метилтіазолу з різними замісниками в положеннях 3 і 5. Наявність N(3)-бензильного замісника забезпечує найкраще закріплення інгібітора в каталітичному аніонному сайті, тоді як ацильні фрагменти замісників у положенні 5 розташовуються в області периферичного аніонного сайту. Логарифми значень ІС50, за виключенням сполук з О-ацильними карбоциклічними групами, лінійно залежать від розрахованих енергій докінгу як у випадку тіазолієвого іону, так і у разі нейтрального тетраедричного інтермедіату розкриття тіазолієвого циклу.Експериментальна частина. Солі тіазолію синтезовані відомими методами. Активність ацетилхолінестерази визначали за методом Елмана. Молекулярний докінг у область активного центру ацетилхолінестерази здійснено з використанням програми AutoDock 4.2.Висновки. Структурні фрагменти замісників у положеннях 3 і 5 гетероциклічного скафолду забезпечують зв’язування інгібітора в області каталітичного і периферичного аніонних сайтів ацетилхолінестерази, відповідно. Гетероциклічний скафолд може бути зв’язаний у формі тіазолієвого іона або у формі нейтраль-ного тетраедричного інтермедіату розкриття тіазолієвого циклу

Towards an Entropy-based Analysis of Log Variability

Rules, decisions, and workflows are intertwined components depicting the overall process. So far imperative workflow modelling languages have played the major role for the description and analysis of business processes. Despite their undoubted efficacy in representing sequential executions, they hide circumstantial information leading to the enactment of activities, and obscure the rationale behind the verification of requirements, dependencies, and goals. This workshop aimed at providing a platform for the discussion and introduction of new ideas related to the development of a holistic approach that encompasses all those aspects. The objective was to extend the reach of the business process management audience towards the decisions and rules community and increase the integration between different imperative, declarative and hybrid modelling perspectives. Out of the high-quality submitted manuscripts, three papers were accepted for publication, with an acceptance rate of 50%. They contributed to foster a fruitful discussion among the participants about the respective impact and the interplay of decision perspective and the process perspective

Biomarkers of oxidative stress and smoking in cancer patients

Context: Increased oxidative stress is a significant part of pathogenesis of smoking-related cancer. Aim: The study aims to investigate changes in antioxidant status induced by chronic cigarette smoking in cancer patients and healthy subjects. Setting and Design: We examined the venous blood samples of 54 healthy subjects, both smokers (25) and non-smokers and of 50 patients with smoking-related cancer, both smokers (34) and non-smokers. Materials and Methods: We measured the activities of five antioxidant (AO) enzymes: glutathione peroxidase, glutathione transferase (GST), glutathione reductase, superoxide dismutase and catalase in the blood of 50 cancer patients and 54 healthy persons. Damage to cellular structures (level of malonic dialdehyde, micro viscosity of erythrocyte membranes, number of leukocyte DNA breaks) was determined. Statistical analysis of results obtained was performed using conventional and multi-factorial statistical methods. Results: Statistically significant increase in GST activity and DNA breaks, but decrease of membranes micro viscosity in cancer patients, compared with healthy subjects were obtained. In the cancer patients, no influence of smoking on studied parameters was found. Correlations of parameters within cancer patients and healthy subjects group did not coincide with each other. Conclusions: Changes of AO status parameters and oxidative damages in cell structures are related to tumor processes indicating the augmentation of oxidative stress in human blood. This study demonstrated potential applicability of a statistical model based on the evaluated biomarkers of oxidative stress to determine a smoking-induced harm of cancer incidence in healthy subjects

Mutual information for the selection of relevant variables in spectrometric nonlinear modelling

Data from spectrophotometers form vectors of a large number of exploitable variables. Building quantitative models using these variables most often requires using a smaller set of variables than the initial one. Indeed, a too large number of input variables to a model results in a too large number of parameters, leading to overfitting and poor generalization abilities. In this paper, we suggest the use of the mutual information measure to select variables from the initial set. The mutual information measures the information content in input variables with respect to the model output, without making any assumption on the model that will be used; it is thus suitable for nonlinear modelling. In addition, it leads to the selection of variables among the initial set, and not to linear or nonlinear combinations of them. Without decreasing the model performances compared to other variable projection methods, it allows therefore a greater interpretability of the results

HERMES: Towards an Integrated Toolbox to Characterize Functional and Effective Brain Connectivity

The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time series analysis. In neurophysiology, different analytical tools stemming from these concepts have added to the ‘traditional’ set of linear methods, which includes the cross-correlation and the coherency function in the time and frequency domain, respectively, or more elaborated tools such as Granger Causality. This increase in the number of approaches to tackle the existence of functional (FC) or effective connectivity (EC) between two (or among many) neural networks, along with the mathematical complexity of the corresponding time series analysis tools, makes it desirable to arrange them into a unified-easy-to-use software package. The goal is to allow neuroscientists, neurophysiologists and researchers from related fields to easily access and make use of these analysis methods from a single integrated toolbox. Here we present HERMES (http://hermes.ctb.upm.es), a toolbox for the Matlab® environment (The Mathworks, Inc), which is designed to study functional and effective brain connectivity from neurophysiological data such as multivariate EEG and/or MEG records. It includes also visualization tools and statistical methods to address the problem of multiple comparisons. We believe that this toolbox will be very helpful to all the researchers working in the emerging field of brain connectivity analysis

Модернізація промислових роботів

Модернізація промислових роботів = Modernization of industrial robots / Д. Ю. Шарейко, І. С. Білюк, О. С. Садовий, О. В. Савченко, А. М. Фоменко, А. В. Козаченко // Вісн. ПДТУ. Сер. Технічні науки. – Маріуполь : ДВНЗ «ПДТУ», 2020. – Вип. 41. – С. 99–108.Наведено спосіб модернізації промислових роботів за рахунок використання синхронних сервоелектродвигунів з цифровою системою керування. Цифрова система керування може бути побудована або на основі контролера, або з використанням ЕОМ. Отримана методика розрахунку параметрів цифрового регулятора на задані показники якості керування.The method of modernization of industrial robots due to the use of synchronous servo electric motors with a digital control system has been given. The digital control system can be arranged either on the basis of the controller, or with the use of a computer. The method of calculation of the digital regulator parameters to get the set indicators of control quality has been received. The use of digital controllers makes it possible not only to improve the control quality, but also to increase the margin of stability. Modern frequency converters that are part of complete electric drives already contain speed and current regulators. These regulators are arranged on different control principles: PI, PD, PID. The parameters of these controls are set in software and cannot be changed in any other way. An alternative is to use a programmable logic controller (PLC). It is connected through the digital inputs of the frequency converter and can also receive information through the digital outputs of that very frequency converter. However, unlike the fixed controllers, which are part of the frequency converter and are set up according to the specifications of the electric drive in accordance with the known methods of linear systems, the setting-up of the PLC software digital controller requires programming in a special programming language for this controller. In addition, the controller can change the settings of the regulators and the regulation law itself, turning the control system into an adaptive one. Therefore, the solution to the problem of setting-up digital controllers is entirely relevant, especially when connecting an electric drive to a computer. This improves the user’s dialogue, making it possible to reset up the parameters of the regulators and the control law. In modern robotic manipulators with stringent requirements for positioning accuracy, synchronous servo electric drives are widely used, which are replacing stepper drives. The exception is electric drives with piezoceramic actuators. But they are used in low-power robots. The paper provides an example of calculating the parameters of a digital controller using the method of logarithmic frequency characteristics