Hybrid Power Sources/Systems (HPS) are generally treated as local prosumer supplies. The paper presents a new approach to the strategy of electricity contracting from HPS, considering hybrid systems as a new type of quasi-centrally dispatched power units operating in Polish market conditions. The possibilities of contracting electricity from HPS, consisting of three electricity...
This paper presents the concept of using algorithms for reducing the dimensions of finite-difference equations of two-dimensional (2D) problems, for second-order partial differential equations. Solutions are predicted as two-variable functions over the rectangular domain, which are periodic with respect to each variable and which repeat outside the domain. Novel finite-difference...
In this work, we present a failure detection system in sensors of any robot. It is based on the k-fold cross-validation approach and built from N neural networks, where N is the number of signals read from sensors. Our tests were carried out using an unmanned aerial vehicle (UAV, quadrocopter), where signals were read from three sensors: accelerometer, magnetometer and gyroscope...
In this paper, an advanced study covering the comparison between two classes of generalized inverses is conducted. Two sets of instances, strictly derived from the recently introduced nonunique S- and σ-inverse, are analyzed, especially in terms of degrees of freedom-oriented interchangeable application in different engineering tasks. Henceforth, the respective collections of...
Necessary and sufficient conditions for the pointwise completeness and the pointwise degeneracy of linear discrete-time different fractional order systems are established. It is shown that if the fractional system is pointwise complete in one step (q = 1), then it is also pointwise complete for q = 2, 3…
This paper presents a deep learning-based image texture recognition system. The methodology taken in this solution is formed in a bottom-up manner. It means we swipe a moving window through the image in order to categorize if a given region belongs to one of the classes seen in the training process. This categorization is done based on the Deep Neural Network (DNN) of fixed...
The paper proposes an adaptation of mathematical models derived from the theory of deterministic chaos to short-term power forecasts of wind turbines. The operation of wind power plants and the generated power depend mainly on the wind speed at a given location. It is a stochastic process dependent on many factors and very difficult to predict. Classical forecasting models are...
We propose an approach to indirectly learn the Web Ontology Language OWL 2 property characteristics as an explanation for a deep recurrent neural network (RNN). The input is a knowledge graph represented in Resource Description Framework (RDF) and the output are scored axioms representing the characteristics. The proposed method is capable of learning all the characteristics...
The subject matter of the research pertains to the improvement of rheological properties of petroleum bitumens by their modification with SBS (styrene-butadiene-styrene) copolymer. The authors have determined selected rheological properties characterising the durability of modified bitumens used in road pavements. The bitumens were modified in laboratory conditions with modified...
Several recent earthquakes have indicated that the design and construction of bridges based on former seismic design provisions are susceptible to fatal collapse triggered by the failure of reinforced concrete columns. This paper incorporates an experimental investigation into the seismic response of nonductile bridge piers strengthened with low-cost glass fiber reinforced...
An improved damage detection index for a structural component is proposed, using eigenvalues estimated by means of frequency domain decomposition (FDD) and mode contribution subjected to ambient excitation. It is based on vibration measurements obtained from the acceleration data of a simple steel beam. Since the extraction of modal parameters involves practical limitations and...
The main objective of this work is to present an innovative method of numerical modeling of anchored piles system acting as a road protection against landslide, called the “2D/3D method”. Firstly, short description of the problem and “state of the art” review are included. An effective methodology of the design supported by the numerical analysis, solving the problem of...
The effect of laser processing on the structure, microstructure and hardness of high-speed steel produced by powder metallurgy was investigated. The samples were surfaces remelted with impulse CO2 laser radiation under different operation conditions. In the remelted layer, the presence of full remelting, partial remelting and heat affected zones was detected. As a result of...
Industries that rely on additive manufacturing of metallic parts, especially biomedical companies, require material science-based knowledge of how process parameters and methods affect the properties of manufactured elements, but such phenomena are incompletely understood. In this study, we investigated the influence of selective laser melting (SLM) process parameters and...
Metal matrix composites (MMC) are finding application in many fields such as aerospace and automobile industries. This is due to their advantages such as light weight and low cost. Among all the available non-traditional machining processes, wire electric discharge machining (WEDM) is found to be a suitable method for producing complex or intricate shapes in composite materials...
This research paper discusses the friction and wear behaviour of Al-12Si alloy reinforced with B4C prepared through Powder Metallurgy (P/M) method by varying the weight percentage of reinforcement (x = 2, 4, 6, 8, and 10) content. The samples were prepared by using die and punch assembly and the lubricant used to eject the sample from the die was molybdenum disulfide. The...
The present work focuses on the fabrication of glass fiber and multifilament discarded fishnet nylon fiber polymer composites with four different fiber compositions. Composites are molded by means of simple hand lay-up methodology with dissimilar layers of the fiber mat. The mechanical characterization (tensile and impact) and thermal analysis of composites have to be...
The main drawback of vibration-based energy harvesting is its poor efficiency due to small amplitudes of vibration and low sensitivity at frequencies far from resonant frequency. The performance of electromagnetic energy harvester can be improved by using mechanical enhancements such as mechanical amplifiers or spring bumpers. The mechanical amplifiers increase range of movement...
The problems of mathematical modelling of vibration signal for bearings with specific geometrical structure or defect is important insofar as there are no model bearings (to facilitate carrying out a calibration procedure for industrial measurement systems). It is even more so that there are no precise reference systems to which we would compare the results. This article presents...
In this paper, quanizted multisine inputs for a maneuver with simultaneous elevator, aileron and rudder deflections are presented. The inputs were designed for 9 quantization levels. A nonlinear aircraft model was exited with the designed inputs and its stability and control derivatives were identified. Time domain output error method with maximum likelihood principle and a...
Most high-pressure fuel pumps for compression-ignition engines manufactured today are cam driven. These pumps have numerous advantages, such as low energy consumption and limited production costs. However, a problem arising from the nature of the cam mechanism is an unfavorable distribution of forces in the camshaft-plunger-cylinder system of a delivery section. The authors have...
The article describes the results of combustion of a mixture of PCOME (purified cooking oil esters) and bioethanol in the compression ignition Perkins 1104C-44 engine. The engine was prepared for use with the classic type of fuel – diesel oil, not biofuels. That is why bioethanol was added to ester in tests so that the basic physicochemical properties of the obtained mixture were...
This paper presents equilibrium mechanics and a finite element model for analysing a scissor structure that contains pivots with zero bending stiffness representing structural instability. The pivot at the centre of each structural unit, which is a feature of scissor structures, can be used to transfer the displacement between the units. It cannot, however, transfer the rotation...
Pot-cored coils are commonly used as probes in eddy current testing. In this paper, an analytical model of such a coil placed over a three-layer plate with a hole has been presented. The proposed solution enables the modelling of both magnetic and non-magnetic conductive plates that contain different types of hole, i.e. a through, a surface, an inner or a subsurface hole. The...
In this paper, a new dynamic model was proposed for identifying the rock hardness during the process of roadway tunnelling, thereby regulating the speed of the driving motor and the torque of the cutting head. The presented identification model establishes a multi-information feature database containing vibration signals in the y-axis, acoustic emission signals, cutting current...