Machine Learning as a method of adapting offers to the clients

Recommendation systems are class of information filter applications whose main goal is to provide personalized recommendations. The main goal of the research was to compare two ways of creating personalized recommendations. The recommendation system was built on the basis of a content-based cognitive filtering method and on the basis of a collaborative filtering method based on user ratings. The conclusions of the research show the advantages and disadvantages of both methods

Semimartingales and Shrinkage of Filtration

We consider a complete probability space $(\Omega,\mathcal{F},\mathbb{P})$, which is endowed with two filtrations, $\mathbb{G}$ and $\mathbb{F}$, assumed to satisfy the usual conditions and such that $\mathbb{F} \subset \mathbb{G}$. On this probability space we consider a real valued special $\mathbb{G}$-semimartingale $X$. The purpose of this work is to study the following two problems: A. If $X$ is $\mathbb{F}$-adapted, compute the $\mathbb{F}$-semimartingale characteristics of $X$ in terms of the $\mathbb{G}$-semimartingale characteristics of $X$. B. If $X$ is not $\mathbb{F}$-adapted, given that the $\mathbb{F}$-optional projection of $X$ is a special semimartingale, compute the $\mathbb{F}$-semimartingale characteristics of $\mathbb{F}$-optional projection of $X$ in terms of the $\mathbb{G}$-canonical decomposition and $\mathbb{G}$-semimartingale characteristics of $X$

Impact of increased temperature of lower end-fitting of a composite long rod insulator on its mechanical strength under variable loads

This paper describes results of tensile mechanical strength testing of two types of composite suspension line insulators from two manufacturers. In order to take into account the operation of composite insulators in overhead transmission lines with high-temperature low-sag (HTLS) conductors, the testing of their static and fatigue strength was performed at both ambient and elevated temperatures. The results showed that the static mechanical strength of composite insulators decreased with an increase in the temperature of the lower end fitting of the insulator, and proved that it followed a third-degree polynomial function. Calculations performed demonstrated that a significant cause of reduction in strength was the increase in the radial stress following the temperature increase in the crimped glassepoxy resin core of the insulator. The results of the fatigue strength testing demonstrated that the increase in the temperature of the lower end fitting of the insulator up to 85°C degree had a little effect on the fatigue strength of the tested composite insulators

Optical wireless communications operated at long-wave infrared radiation

This paper presents some construction analysis and test results of a Free Space Optics system operating at the wavelength of 9.35 µm. In the system, a quantum cascade laser and a photoreceiver with mercury cadmium telluride photodetectors were used. The main parameters of these elements were discussed taking into account a data link operation. It also provides to determine a data range for various weather conditions related to scattering and scintillation. The results of numerical analyses defined the properties of currently available FSO technologies working in the near infrared or in the short infrared range of spectrum versus the performances of the developed system. The operation of this system was verified in three different test environments. The obtained results may also contain important issues related to the practical application of any FSO system

Optical wireless communications operated at long-wave infrared radiation

This paper presents some construction analysis and test results of a Free Space Optics system operating at the wavelength of 9.35 µm. In the system, a quantum cascade laser and a photoreceiver with mercury cadmium telluride photodetectors were used. The main parameters of these elements were discussed taking into account a data link operation. It also provides to determine a data range for various weather conditions related to scattering and scintillation. The results of numerical analyses defined the properties of currently available FSO technologies working in the near infrared or in the short infrared range of spectrum versus the performances of the developed system. The operation of this system was verified in three different test environments. The obtained results may also contain important issues related to the practical application of any FSO system