bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific features of feed-forward neural networks application in classification and regression problems in algology
Authors: Grigoryeva N Yu , Zhangirov T R , Liss A A 
Published: February 2021

Abstract
Abundance and biological diversity of phytoplankton communities, investigated in this work, are often used as a marker for the determination of environmental health and fresh water quality. Presently their routine analysis is very time consuming and expensive. A lot of articles are devoted to the development of a system for an in situ automated analysis of phytoplankton properties. However, the applied problems of biology, ecology and, in particular, algology usually are associated with some difficulties due to shortage and/or fuzziness of the experimental data. Hence, while using neural network modelling a set of specific problems can occur. In this article on the base of experimental data several such problems are presented and possible solutions are suggested. In particular, the illogical behavior of classifying neural network is revealed, while studying the biological diversity of cyanobacteria, and the original technique for results validation is presented. This problem is investigated on a set of spectroscopic data, recorded by means of confocal laser scanning microscopy. The generalization quality of the trained model is studied as the main learning parameter. Another problem of shortage dataset is examined in the frames of regression model for bioplankton abundance. This problem is solved by means of feed-forward back-propagation neural networks with two hidden layers. The modelling was carried out on a small experimental selection (only 39 observations were available), despite this, the relatively high determination coefficient was obtained for the training and test samples, while using dropout layout.
The minimum cost flow finding under fuzzy intuitionistic conditions
Authors: Gerasimenko E , Kureichik V 
Published: February 2021

Abstract
Present paper deals with the minimum cost flow finding task with fuzzy trapezoidal intuitionistic values of arc capacities and costs. Nowadays, flow tasks in networks are leading tasks in flow modelling and urban logistics. Peculiarity of the problem is in optimal paths finding, which allows decreasing the total cost of transportation and choosing the best paths for transportation. Fuzzy logic as a powerful tool for dealing with uncertainty, vagueness and inaccurate data influenced the way of presenting characteristics of networks. Arc capacities and costs can be presented as fuzzy numbers of the different form enabling researchers to get more reliable solutions. However, during the simulation a researcher is often faced with difficulties in exact specifying of arc capacities and costs. It is a commonplace that experts hesitate or have doubts choosing a specific value for parameters of the network. In such circumstances arc capacities and costs can be presented in a fuzzy intuitionistic form, in particular, as fuzzy intuitionistic triangular or trapezoidal numbers. A fuzzy intuitionistic number allows taking into account a level of hesitation by including degree of membership, non-membership and indeterminacy margin. Incorporating fuzzy intuitionistic sets into conventional flow patterns enables researchers to solve tasks in fuzzy, vague conditions even when there is a lack of necessary data for problem statement. The main contribution to the paper is the proposal for the fuzzy intuitionistic minimum cost flow algorithm using fuzzy intuitionistic flow patterns based on the ranking technique and arithmetic operations with fuzzy intuitionistic trapezoidal numbers. A case study numerical is presented to illustrate the proposed algorithm.
Qualitative measure of the environment risk level for the fuzzy control systems of environmental safety
Authors: Novikova S V , Tunakova Y A , Shagidullin A R , Novikova K N 
Published: February 2021

Abstract
When creating an environmental management system that should generate a control actions set for regulating the quality of natural objects, it is necessary to be able to “calculate” the qualitative value of the environment state. A qualitative assessment of the environment state is a generalized measure of natural risk. For these purposes, it is very convenient to use the so-called “soft” models that take into account the fuzzy nature of information - a fuzzy inference system and neuro-fuzzy systems. The main advantage of the neuro-fuzzy model over the regression one is the consideration of the ambiguity and fuzziness of the concepts “Acceptable”, “Medium”, “High”, “Unacceptable” and “Catastrophic” risks, as well as the possibility of adaptive correction due to the training of a fuzzy neural network on experimental data.
The calculation of the qualitative values for degree of danger to the environment is important not only in itself, but also as a criterion for making management decisions to normalize or prevent dangerous situations. To develop environmental recommendations on management impacts, the concept of “Risk Measure” is considered in the work, which corresponds to the management decisions made. The criterion “Risk Measure” takes values in the range from 1 to the number of tuples of the experimental sample, and the higher the Measure value, the more global the measures are recommended. Each value can be associated with either a single action or a set of actions. Thus, greater flexibility in the use of the system is achieved, and the range of recommended measures that can compensate for the emerging risks is significantly expanded.
The article describes an algorithm for calculating a quality risk measure. The theory is confirmed by computational experiments using in fuzzy control systems.
A problem of long distances in the educational environment
Authors: Nikiforov I S , Paderno P I 
Published: February 2021

Abstract
A process of the specialist’s professional development involve two aspects of the decision-making support: choosing a field of study (by an applicant) and choosing an applicant for a job position and training (by a company). The correctness of solving this task depends greatly on developing methods allowing to identify potential of an applicant. The goal of this research is developing a formalized approach to create the metrics in the educational environment, which would allow comparing applicants to each other in terms of compliance with the requirements of a certain job. The methods: the research uses system analysis approaches; models of characteristics changing during the training; scaling of heterogeneous values; integrating particular estimations (getting integral estimation) based on expert opinions. The results: the analysis allowed identify a set of dependencies related both to a study subject and job requirements, distinctive features and resource characteristics of learning technologies. Several models and an approach to assessing a prospective applicant were suggested taking into account a multi-dimensional resource, which is required to train a certain applicant up to the required level. The practical relevance: the suggested approach allows to make formalized setting and further addressing a set of evaluation and optimization tasks related both to the best choice of future job (for an applicant), and a choice of most promising applicants and learning techniques (for a company).
Pseudo-bulk SAW transducers fabricated in GaN epitaxial layers grown on sapphire substrate
Authors: Paszkiewicz B , Gierz Ł 
Published: February 2021

Abstract
Gallium nitride is a material commonly applied to the fabrication of various semiconductor devices, naming High Electron Mobility Transistors (HEMT) and Light Emitting Diodes (LED). Its unique feature is that it also possesses good piezoelectric properties. This enables to produce devices that integrate both active transistor operation and signal processing and filtration in one monolithic chip. This aim requires a comprehensive analysis of the acoustic wave propagation in the gan/sapphire system. Particularly attractive in the construction of modern acoustic instruments, due to higher propagation speeds, is the utilisation of pseudo-bulk mods. This paper presents the results of research on Surface Acoustic Wave (SAW) transducers using pseudo-bulk waves propagating in thin (2-6 μm) layers of GaN on sapphire. The layers were made by the MOVPE process using a low-temperature buffer layer. Transducers with a two-finger pitch of 9 and 18 μm with 48 and 24 periods respectively were made using electron lithography. Low finger resistivity was achieved by using Ru/Au/Ti/Au metal alloy. The results of microwave measurements identifying particular pseudo-bulk mods and their dispersion characteristics are presented. Two pseudo-bulk mods were observed, the first one with a propagation velocity range of 8500-7800 ms−1 and the second one of 7200-7300 ms−1. Additionally, pseudo-bulk modes were also compared with classical Rayleigh modes generated in the same transducers at lower frequencies. The results are important from the point of view of possible monolithic integration of the tested transducers with High Electron Mobility Transistors.
Research on the measurement of spraying time with seed treatment agent using an innovative valve
Authors: Semkło Ł , Gierz Ł 
Published: February 2021

Abstract
The demand for agricultural products increases with limited access to agricultural land. As a result, there is an increase in yield owing to new techniques applied to agriculture, i.e. precise seed potatoes treatment. For this purpose, the dressing of seed potatoes was tested using the author’s method of checking the quality of spraying with dressing agent and improving seed coverage. In the hereby work, the method of image analysis was used to detect the movement of particles of working liquid. The article presents a test stand for measuring spraying time after exiting an innovative pressure-pneumatic valve using image analysis. The analysis was made using a fast Cronos 1.4 camera. The subject of the research was the construction of the station and evaluation of the work of the innovative pressure-pneumatic valve in two configurations: without the addition of compressed air and using additional compressed air.
Numerical analysis issues in the evaluation of the helicopter’s main rotor stability
Authors: Raczyński R , Siadkowska K 
Published: February 2021

Abstract
The paper presents selected aspects of numerical analyses on the assessment of the helicopter’s main rotor operational stability, presents key issues for stability assessment, and discusses the application of the co-simulation methodology for helicopter’s main rotor exampled by a prototype unmanned aerial vehicle rotor. The presented approach enables the analysis and mapping of the rotor’s operation taking into account the effects of the aeroelasticity of the blade itself. The impact of wind on the tested structure is presented for two cases and thrust force for the cases of starting the rotor for front and crosswind was evaluated. The transition of the rotor between the idle and working revolutions at a small collective angle does not generate unstable states independently in the wind direction.
Assessment of influence of addition of potassium drilling fluid on potassium content in activated sludge in wastewater treatment process in SBR reactors
Authors: Cel W 
Published: February 2021

Abstract
The activated sludge is described as a complex biological system composed of microorganisms. Within this system, processes of both physical and biochemical nature undergo, resulting in the purification of wastewater as well as industrial sewage. Recent researches indicate also on a possibility of co-treatment via activated sludge of used drilling fluids. As a result of wastewater treatment, sewage sludge is being formed, which according to its composition may become a waste to dispose or a product for natural reuse. The hereby paper presents the influence on potassium content in the activated sludge of addition of used drilling fluids (volume ranging from 0.25% to 4% of the volume of treated wastewater), which may have an impact on the final natural use of sludge.
Strength analysis of the rotor hub of an unmanned helicopter
Authors: Cygnarowska K , Czyż Z , Karpiński P , Skiba K 
Published: February 2021

Abstract
This article presents a method of strength analysis of the rotorcraft component which is the rotor hub of an unmanned helicopter with a MTOW up to 150 kg. The simulation takes into account two materials of which individual elements are made, i.e. steel and aluminum alloy. The load scheme and element support were defined, and numerical calculations were performed in the Ansys Workbench software. The simulation results were presented in the form of stress maps and were subjected to detailed analysis for individual elements. In the last stage, critical places in the assessment of the strength of the elements were indicated. On the basis of the performed strength analysis, the obtained results were individually interpreted for each of the tested elements depending on the adopted safety factors.
Evaluation of the diagnostic accuracy of MRI in detection of knee cartilage lesions using Receiver Operating Characteristic curves
Authors: Krakowski P , Karpiński R , Maciejewski R , Jonak J 
Published: February 2021

Abstract
Medical treatment, and especially surgical procedures, is carefully planned and executed based on various diagnostic methods. Physical examination provides preliminary information about the patient’s health; however, when orthopaedic surgery is concerned, more accurate radiological evaluation is necessary. MRI is perceived as a state-of-the-art radiological modality. In this study, we have evaluated MRI efficiency in detecting chondral lesions in the knee joint requiring surgical treatment. The evaluation of selected diagnostic methods used in the assessment of joint cartilage damage was carried out based on statistical indicators and ROC (Receiver Operating Characteristic) curves. The indicators were determined using Statistica and Matlab software. 95. patients underwent knee arthroscopy subsequently after performing MRI for various intraarticular lesions. Chondral lesions estimated with the use of the ICRS scale were divided into two groups, one requiring surgical treatment ICRS grade 3-4, and selected for conservative treatment ICRS grade 0-2. Results were evaluated with the use of ROC curves. MFC was the most common lesion site, where chondral lesions requiring surgical intervention were found in nearly 50% of patients. LTC was affected only in 9 patients, which was the rarest location for chondral lesions. The diagnostic efficiency for each anatomical location was evaluated. The highest diagnostic accuracy was found on MFC followed by LTC. The lowest diagnostic accuracy was found for PFJ. The AUC ranged from 0.8438 for MFC to 0.55 for PFJ. LFC and MTC showed similar accuracy with AUC respectively 0.6419 and 0. 6623. To sum up, MRI is a gold standard for cartilage evaluation, however, its accuracy differs among various anatomical locations, therefore requires a thorough assessment prior to surgical planning.
An enhanced fuzzy logic based strategy for non-disruptive load shedding and the predictive energy management system
Authors: Waheed W , Qingshan X , Abdullah M P 
Published: February 2021

Abstract
Electrical energy capacity mismatch and immense power shortages due to energy deficit in the power system keep on increasing because of inadequate power capacity, insufficient investment, demand growth, and the rise in living standards. To maintain a balanced relationship between production and consumption, several load shedding schemes have been implemented for load management in the last few years, but their inconsistency poses a challenge. This research work will apply the fuzzy logic algorithm (FLA) and optimise the existing conventional power systems with and without dispersed generators (DGs). In critical circumstances, the algorithm will find node sets or desired locations where limits are violated and system operators may request the utility or industrial customer to shed a required amount of load by operating distributed generators to maintain its system integrity. The performance and suitability of the proposed scheme are demonstrated and proved by testing on a standard 33-bus radial distribution system in MATLAB Simulink having an objective function of minimising its total load curtailed and reducing power system losses by improving its system stability.
Application of the Darcy and Richards equations for modelling of water capillary rise in building materials
Authors: Widomski M K , Łagód G , Suchorab Z , Pavlikova M , Pavlik Z , Zaleska M 
Published: February 2021

Abstract
This paper presents the application of the Darcy and Richards equations, describing water flow and dynamic changes of the water content in porous medium, for numerical modeling of water capillary rise in the selected building materials. The numerical simulations of unsaturated and variably saturated water flow in the studied materials were performed in FEFLOW commercial computational software, by DHI-Wasy, Germany. The developed model represented a wall section constructed of aerated concrete blocks, covered by mortar prepared using blended cement with biomass ash addition. The physical and water retention characteristics of the modeled materials were based on the previously performed laboratory measurements and literature research. The assumed initial conditions reflected air dry wall with limited moisture, while the boundary conditions allowed modeling of capillary rise due to direct contact of the studied materials with water with variable pressure head. The results of numerical calculations allowed observation of the time-dependent changes in the moisture content of building materials in relation to their physical properties and variable boundary conditions.
Assessment of the air purifier effectiveness under model conditions
Authors: Staszowska A 
Published: February 2021

Abstract
The aim of this study was to evaluate the operation of a stationary air purifier under the model conditions of a non-occupied test chamber with dimensions similar to a typical living room. The purifier was equipped with a system for neutralization of volatile organic compounds, disinfection (neutralizing chamber with a system of UVA lamps, plates made of TiO2, UVC lamp settings) and HEPA filters at the air outlet of the device. The conducted research focused on the effectiveness of removing bacterial bioaerosols (M. luteus and B. subtilis) as well as formaldehyde and the sum of volatile organic compounds. The assessment was made for two ranges of fan flow, 100 and 300 m3 / h (Standard and Turbo). The unit shows high efficiency in removing the tested bacterial strains, i.e. 100% after 60 and 90 minutes, respectively. Higher efficiency occurred for lower fan output. However, its effectiveness in removing TVOCs did not exceed 58%. Additionally, the formation of formaldehyde was noted during the operation of the purifier.
Modelling AOB-NOB competition in shortcut nitrification compared with conventional nitrification-denitrification process
Authors: Drewnowski J , Shourjeh M S , Kowal P , Cel W 
Published: February 2021

Abstract
In particular, mainstream deammonification and/or shortened nitrification-denitrification via nitrite (so-called “nitrite shunt”) is a promising new treatment concept that has the potential to revolutionise how nitrogen removal is achieved at WWTPs. Understanding the role of the AOB/NOB competition in the nitrogen cycle in wastewater treatment systems will change operational strategies of the novel nitrogen removal processes. The key role in this process is inhibition of NOB activity undesirably affects AOB activity and leads to inefficient partial nitrification process and when used as pre-treatment for Anammox it can limit nitrite supply to Anammox bacteria. Successful NOB repression requires a combination of such factors as a low DO concentration, a rapid transition from aerobic to anoxic conditions, and tight control of Temperature and/or pH. The major driving force behind the successful NOB washout is the inhibition of those bacteria based on the difference in the growth rate between AOB and NOB. The obtained results from this study show the mechanisms and operating conditions (e.g. DO concentration, Temp.) leading to complete domination of AOB over NOB under aerobic conditions. This paper presents the perspectives on modelling AOB-NOB competition in shortcut nitrification. The combined deammonification, shortened nitrification-denitrification and/or nitritation-anammox process was compared with conventional nitrification-denitrification based on own experiments and literature data. Its successful application as shortcut nitrification technology and new control system will represent a paradigm shift for the wastewater industry, offering the opportunity for sustainable wastewater treatment, energy-neutral or even energy-positive facilities, and substantial reductions in treatment costs.
Obtaining the 3D geometry of the blade in a training aircraft
Authors: Bąbel R , Sawicki K , Gąsiorowski M 
Published: February 2021

Abstract
The blade whose task is to generate together with the hub engine thrust is one of the most important construction elements of a propulsion unit in the PZL 130 Orlik trainer The design of appropriate profiles of the blade determines its efficiency and thus is one of the most important construction tasks due to complex blade shapes. After designing and manufacturing the blade, it is advisable to tests any possible geometric deviations in the model blade. It is also essential to carry out tests to specify changes in its geometry after a specified number of flying hours to inspect the risk of damage to the blade during its operation. Moreover, a number of studies are conducted on icing which occurs on the airframe and the blade itself. The aim of this paper is to present a technique of 3D scanning applied to the training aircraft blade so as to copy its precise geometry after a specified period of operation. Scanning enables the use of a created geometry for numerical analyses, in particular of icing during aircraft operation. The Nikon Maker MMDx scanner and the GeoMagic Design X Software were used to create the 3D model and scan the blade of the PZL 130 Orlik training aircraft.
Determining aircraft aerodynamic characteristics of regular and non-linear airframes and evaluating the efficiency of the applied methods
Authors: Uliczka M , Smykla I 
Published: February 2021

Abstract
This paper discusses three methods of determining aerodynamic characteristics and compares the research results. The research cases are two planes selected by the authors, i.e. EM-10 Bielik and YOKOSUKA MXY7 OHKA and investigated as an airframe with the so-called non-linear aerodynamic flow and a classical design. Aerodynamic characteristics was determined by the following methods: aerospace engineering formulas, CAD simulation of the airflow around the object and examining the prototype in a wind tunnel. The last section of the paper compares the obtained results and evaluates the efficiency of all methods to examine both types of the aircraft. The compared parameters are lift and drag versus angles of attack and aircraft polars.