Malicious and benign websites classification using machine learning methods

Nowadays web surfing is an integral part of the life of the average person and everyone would like to protect his own data from thieves and malicious web pages. Therefore, this paper proposes a solution to the discrimination of malicious and benign websites problem with desirable accuracy. We propose to utilize machine learning methods for classification malicious and benign websites based on URL and other host-based features. State-of-the-art gradient-boosted decision trees are proposed to use for this task and they have been compared with well-known machine learning methods as random forest and multilayer perceptron. It was shown that all machine learning methods provided desirable accuracy which is higher than 95% for solving this problem and proposed gradient-boosted decision trees outperforms random forest and neural network approach in this case in terms of both overall accuracy and f1-score

АНАЛИЗ КОНСТРУКЦИЙ ШИХТОВАННЫХ МАГНИТОПРОВОДОВ СИЛОВЫХ ТРЕХФАЗНЫХ ТРАНСФОРМАТОРОВ

Analysis and research into properties and parameters of different-type laminated magnetic cores of three-phase power transformers are conducted. Most of new laminated magnetic core designs are found to have significant shortcomings resulted from design and technological features of their manufacturing. These shortcomings cause increase in ohmic loss in the magnetic core, which eliminates advantages of the new core configurations and makes them uncompetitive as compared with the classical laminated magnetic core design.Проведен анализ и исследование свойств и параметров различных типов шихтованных магнитопроводов силовых трехфазных трансформаторов. Установлено, что большинство новых конструкций шихтованных магнитопроводов, обладают серьезными недостатками, вызванными конструктивными и технологическими особенностями процесса их изготовления. Эти недостатки ведут к увеличению активных потерь в магнитопроводе, что нивелирует их достоинства и не позволяет им конкурировать с классической шихтованной конструкцией магнитопровода.Проведено аналіз та дослідження властивостей й параметрів різних типів шихтованих магнітопроводів силових трифазних трансформаторів. Встановлено, що більшість нових конструкцій шихтованих магнітопроводів мають серйозні недоліками, викликані конструкційними й технологічними особливостями процесу їх виготовлення. Ці недоліки ведуть до збільшення активних втрат у магнітопроводі, що нівелює їх переваги та не дозволяє їм конкурувати із класичною шихтованою конструкцією магнітопроводу

Developing food, water and energy nexus workflows

There is a growing recognition of the interdependencies among the supply systems that rely upon food, water and energy. Billions of people lack safe and sufficient access to these systems, coupled with a rapidly growing global demand and increasing resource constraints. Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors, however development of nexus related frameworks has been limited. We describe three open- source models well known in their respective domains (i.e. TerrSysMP, WOFOST and SWAT) where components of each if combined could help decision-makers address the nexus issue. We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework. The outputs of the workflows and the model framework are designed to address the SDG

Branch Rings, Thinned Rings, Tree Enveloping Rings

We develop the theory of ``branch algebras'', which are infinite-dimensional associative algebras that are isomorphic, up to taking subrings of finite codimension, to a matrix ring over themselves. The main examples come from groups acting on trees. In particular, for every field k we construct a k-algebra K which (1) is finitely generated and infinite-dimensional, but has only finite-dimensional quotients; (2) has a subalgebra of finite codimension, isomorphic to $M_2(K)$; (3) is prime; (4) has quadratic growth, and therefore Gelfand-Kirillov dimension 2; (5) is recursively presented; (6) satisfies no identity; (7) contains a transcendental, invertible element; (8) is semiprimitive if k has characteristic $\neq2$; (9) is graded if k has characteristic 2; (10) is primitive if k is a non-algebraic extension of GF(2); (11) is graded nil and Jacobson radical if k is an algebraic extension of GF(2).Comment: 35 pages; small changes wrt previous versio

Всеукраїнська XIV науково-практична конференція студентів, аспiрантiв та молодих вчених «Теоретичні i прикладні проблеми фізики, математики та інформатики»

In this work existing major initiatives on LCLUC, overview of methodological aspects (state-of the art review) and future developments in the domain of LCLUC are described

НОВЫЕ ПОДХОДЫ ПРИ ПОСТРОЕНИИ МАГНИТОПРОВОДОВ СИЛОВЫХ ТРАНСФОРМАТОРОВ

It is carried out exploration and the assaying of new approaches at construction of stacked laminated cores of mains transformers which consists in simultaneous application in a magnetic conductor of the anisotropic and isotropic electric grade sheet, allowing constructing transformers with the heightened efficiency and with smaller cost.Проведено исследование и анализ новых подходов при построении шихтованных магнитопроводов силовых трансформаторов, которые заключаются в одновременном применении в магнитопроводе анизотропной и изотропной электротехнической стали, позволяющий строить трансформаторы с повышенным коэффициентом полезного действия и с меньшей стоимостью.Проведено дослідження й аналіз нових підходів при побудові шихтованих магнітопроводів силових трансформаторів, які полягають в одночасному використанні в магнітопроводі анізотропної та ізотропної електротехнічної сталі, що дозволяє будувати трансформатори з підвищеним коефіцієнтом корисної дії й з меншою вартістю

НОВЫЕ ПОДХОДЫ ПРИ ПОСТРОЕНИИ МАГНИТОПРОВОДОВ СИЛОВЫХ ТРАНСФОРМАТОРОВ

It is carried out exploration and the assaying of new approaches at construction of stacked laminated cores of mains transformers which consists in simultaneous application in a magnetic conductor of the anisotropic and isotropic electric grade sheet, allowing constructing transformers with the heightened efficiency and with smaller cost.Проведено исследование и анализ новых подходов при построении шихтованных магнитопроводов силовых трансформаторов, которые заключаются в одновременном применении в магнитопроводе анизотропной и изотропной электротехнической стали, позволяющий строить трансформаторы с повышенным коэффициентом полезного действия и с меньшей стоимостью.Проведено дослідження й аналіз нових підходів при побудові шихтованих магнітопроводів силових трансформаторів, які полягають в одночасному використанні в магнітопроводі анізотропної та ізотропної електротехнічної сталі, що дозволяє будувати трансформатори з підвищеним коефіцієнтом корисної дії й з меншою вартістю

Regional scale crop mapping using multi-temporal satellite imagery

One of the problems in dealing with optical images for large territories (more than 10,000 sq. km) is the presence of clouds and shadows that result in having missing values in data sets. In this paper, a new approach to classification of multi-temporal optical satellite imagery with missing data due to clouds and shadows is proposed. First, self-organizing Kohonen maps (SOMs) are used to restore missing pixel values in a time series of satellite imagery. SOMs are trained for each spectral band separately using nonmissing values. Missing values are restored through a special procedure that substitutes input sample's missing components with neuron's weight coefficients. After missing data restoration, a supervised classification is performed for multi-temporal satellite images. An ensemble of neural networks, in particular multilayer perceptrons (MLPs), is proposed. Ensembling of neural networks is done by the technique of average committee, i.e. to calculate the average class probability over classifiers and select the class with the highest average posterior probability for the given input sample. The proposed approach is applied for regional scale crop classification using multi temporal Landsat-8 images for the JECAM test site in Ukraine in 2013. It is shown that ensemble of MLPs provides better performance than a single neural network in terms of overall classification accuracy, kappa coefficient, and producer's and user's accuracies for separate classes. The overall accuracy more than 85% is achieved. The obtained classification map is also validated through estimated crop areas and comparison to official statistics

ОПРЕДЕЛЕНИЕ МАГНИТНЫХ ИНДУКЦИЙ В МАГНИТОПРОВОДАХ СИЛОВЫХ ТРАНСФОРМАТОРОВ ПРИ СОВМЕСТНОМ ИСПОЛЬЗОВАНИИ АНИЗОТРОПНОЙ И ИЗОТРОПНОЙ ЭЛЕКТРОТЕХНИЧЕСКИХ СТАЛЕЙ

Purpose. The development of calculation method to determinate the flux densities in different parts of the magnetic cores of distribution transformers, what built from different types magnetic steel (mixed core). Methodology. The method is based on the scientific positions of Theoretical Electrical Engineering – the theory of the electromagnetic field in nonlinear mediums to determine the distribution of magnetic flux in mixed core of transformer, what are using different types of steel what have the different magnetic properties. Results. The developed method gives possible to make calculation of the flux density and influence of skin effect in different parts of the magnetic cores of distribution transformer, where are used mix of grain oriented (GO) and non grain oriented (NGO) steels. Was determinate the general basic conditions for the calculation of flux density in the laminations from grain and non grain oriented steels of the magnetic core: the strength of magnetic field for the laminations of particular part of mixed core is the same; the sum of the magnetic fluxes in GO and NGO steels in particular part of mixed core is equal with the designed magnetic flux in this part of mixed core. Discover, the magnetic flux in mixed core of the transformer has specific distribution between magnetic steels. The flux density is higher in laminations from GO steel and smaller in laminations from the NGO steel. That is happened because for magnetic flux is easier pass through laminations from GO steel, what has better magnetic conductance than laminations from NGO steel. Originality. The common using of different types of magnetic steels in cores for distribution transformers gives possibility to make design of transformer with low level of no load losses, high efficiency and with optimal cost. Practical value. The determination of the flux density in different parts of magnetic core with GO and NGO steels gives possibility make accurate calculation of no load losses and magnetizing current of the transformer.Разработана методика расчета значений магнитных индукций в частях шихтованных магнитопроводов силовых трансформаторов при совместном использовании разных типов электротехнических сталей, в частности – анизотропной и изотропной, позволяющая в дальнейшем рассчитывать потери в магнитопроводах трансформаторов (потери холостого хода) и ток холостого хода.Розроблено методику розрахунку значень магнітних індукцій у частинах шихтованих магнітопроводів силових трансформаторів при спільному використанні різних типів електротехнічних сталей, зокрема – анізотропної й ізотропної, що дозволяє надалі розраховувати втрати в магнітопроводах трансформаторів (втрати холостого ходу) і струм холостого ходу