Vilnius Gediminas Technical University
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Algorithm Selection for Edge Detection in Satellite Images by Neutrosophic WASPAS Method
Get PDFNowadays, integrated land management is generally governed by the principles of sustainability. Land use management usually is grounded in satellite image information. The detection and monitoring of areas of interest in satellite images is a difficult task. We propose a new methodology for the adaptive selection of edge detection algorithms using visual features of satellite images and the multi-criteria decision-making (MCDM) method. It is not trivial to select the most appropriate method for the chosen satellite images as there is no proper algorithm for all cases as it depends on many factors, like acquisition and content of the raster images, visual features of real-world images, and humans’ visual perception. The edge detection algorithms were ranked according to their suitability for the appropriate satellite images using the neutrosophic weighted aggregated sum product assessment (WASPAS) method. The results obtained using the created methodology were verified with results acquired in an alternative way—using the edge detection algorithms for specific images. This methodology facilitates the selection of a proper edge detector for the chosen image content.This article belongs to the Collection Advanced Methodologies for Sustainability Assessment: Theory and Practic
The Impact of Hemp Shives Impregnated with Selected Plant Oils on Mechanical, Thermal, and Insulating Properties of Polyurethane Composite Foams
No full textPolyurethane (PUR) foams reinforced with 2 wt.% hemp shives (HS) fillers were successfully synthesized. Three different types of HS fillers were evaluated—non-treated HS, HS impregnated with sunflower oil (SO) and HS impregnated with tung oil (TO). The impact of each type of HS fillers on cellular morphology, mechanical performances, thermal stability, and flame retardancy was evaluated. It has been shown that the addition of HS fillers improved the mechanical characteristics of PUR foams. Among all modified series, the greatest improvement was observed after the incorporation of non-treated HS filler—when compared with neat foams, the value of compressive strength increased by ~13%. Moreover, the incorporation of impregnated HS fillers resulted in the improvement of thermal stability and flame retardancy of PUR foams. For example, the addition of both types of impregnated HS fillers significantly decreased the value of heat peak release (pHRR), total smoke release (TSR), and limiting oxygen index (LOI). Moreover, the PUR foams containing impregnated fillers were characterized by improved hydrophobicity and limited water uptake. The obtained results confirmed that the modification of PUR foams with non-treated and impregnated HS fillers may be a successful approach in producing polymeric composites with improved properties.This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Source
MCDM Evaluation of Asset-Based Road Freight Transport Companies Using Key Drivers That Influence the Enterprise Value
No full textBusiness owners are trying to enhance company value by developing growth strategies. Besides, they need to know what supports and drives the attractiveness to potential investors. Previously to determine company value, only financial drivers were used. These are essential drivers; however, even they do not reflect the overall situation. This paper proposes a novel approach for the solution of the problem of business valuation by taking into account both financial and non-financial drivers and by using several MCDM (multiple criteria decision making) methods simultaneously both for establishing weights and for the evaluation itself. World-leading road freight transport companies were selected for a case study. MCDM methods were used for determining the weights of the drivers and comparing the listed companies. Key drivers were identified, and the ranking of companies is provided.This article belongs to the Special Issue Decision Support Systems and Multiple Criteria Decision Making for Sustainable Developmen
Closed Cell Rigid Polyurethane Foams Based on Low Functionality Polyols: Research of Dimensional Stability and Standardised Performance Properties
No full textCurrently, polyurethane foam producers come across the several problems when petroleum-based polyols are replaced with low functionality biomass, or waste-based, polyols. In addition, the dilemma is intensified with regulations that require full or partial replacement of blowing agents that can cause high ozone depletion with alternatives like water, which causes the formation of CO2. Therefore, these gases diffuse out of the foam so quickly that the polymeric cell walls cannot withstand the pressure, consequently causing huge dimensional changes at ambient temperature and humidity. Even though the theoretical stoichiometric balance is correct, the reality shows that it is not enough. Therefore, polyethylene terephthalate waste-based polyol was chosen as a low functionality polyol which was modified with high functionality sucrose-based polyol in order to obtain dimensionally stable polyurethane foams in the density range of 30–40 kg/m3. These more stable foams are characterized by linear changes no higher than 0.5%, short-term water absorption by partial immersion no higher than 0.35 kg/m2, and water vapor resistance factors up to 50. In order to obtain thermally efficient polyurethane foams, conventional blowing agents and water systems were implemented, thus, assuring thermal conductivity values in the range of 0.0198–0.0204 W/(m·K) and obtaining products which conform to all the requirements for performance of sprayed and factory-made polyurethane foam standards EN 14315-1 and EN 13165.This article belongs to the Special Issue Performance Research of Polyurethane Foams and Composite
A Cylinder-Type Multimodal Traveling Wave Piezoelectric Actuator
Get PDFNumerical and experimental investigations of a multimodal piezoelectric traveling wave actuator are presented. The actuator consists of a cylindrical stator with a conical hole and piezoceramic rings that are located at the node of the first longitudinal and second bending vibration modes; one piezoceramic ring is also placed at the bottom of the actuator. The actuator is clamped at the bottom using a special supporting cylinder and a ball bearing. Traveling-wave-type vibrations are excited at the top surface of the cylinder by employing a superposition of the first longitudinal and second bending vibration modes of the stator. The conical hole of the stator is used to amplify the vibration amplitudes of the contact surface. Four electric signals with phase difference of π/2 are used to drive the actuator. Numerical and experimental investigations showed that the proposed actuator is able to generate up to 115 RPM rotation speed at constant preload force.This article belongs to the Special Issue IWPMA (International Workshop on Piezoelectric Materials and Applications in Actuators) 2019This research has received funding from the European Regional Development Fund (Project No 01.2.2-LMT-K-718-01-0010) under a grant agreement with the Research Council of Lithuania
Microdefects of Biocorroded Pipe Steel Surfaces and Safety Assessment of Localized Stress Concentrators
No full textThe effect of sulfate-reducing bacteria (SRB) on the corrosion of steel 20 was investigated. Results demonstrated that the chemical composition of corrosion products, the corrosion rate, and corrosion type were altered due to the adherence of SRB and the subsequent formation of biofilm on the steel 20 surface. The micromechanisms of biocorrosion damage of specimens from pipe steel 20 were quantified on the basis of the microgeometry of the degraded surface and the localization parameters of corrosive stress microconcentrators. Stress concentrators in the vicinity of the micro-cuts, which are the depths of the profilograms, make it possible to evaluate safe (allowable) microcorrosion damage. The proposed approach complements the well-known methods for monitoring biodeterioration of pipe steels. With its help, it was found that a decrease in the corrosion rate of specimens with the addition of an inhibitor does not always clearly indicate its effectiveness. The case where the introduction of an inhibitor led to the destruction of the SRB biofilm on the surface of specimens from steel 20, but caused the activation of local corrosion processes and the formation of a more developed microrelief, is considered. The hollows of such microrelief are potential places of origin of defects, which require additional control
Canonical Correlation Analysis and a New Composite Index on Digitalization and Labor Force in the Context of the Industrial Revolution 4.0
No full textThe current phenomenon of the economy-accelerated digitalization, known as the “Industry 4.0”, will generate both an increased productivity, connectivity and several transformations on the labor force skills. Our research objectives are to determine the influence that digitalization has had on the workforce in several developed countries and to propose a new composite indicator that reflects these dynamics over time. We have used the Canonical Correlation Analysis (CCA) in order to identify and analyze the correlations between two sets of variables, an independent one and a dependent one. Data were collected from the World Bank and World Economic Forum for the years 2018–2019. Based on the results of our research we have determined and made a consistent analysis of the new composite index of digitalization and labor force in 19 countries. The results of our research are relevant and show not only the impact of digitalization on the labor force in different countries, but also the structural changes required by the new economic and social models. Our research can help decision-makers get in advance the necessary measures in the field of labor force in order to ensure a proper integration of these measures into the new economic model based on digitalization.This article belongs to the Special Issue Digitalization and Sustainable Developmen
A Novel Extension of the TOPSIS Method Adapted for the Use of Single-Valued Neutrosophic Sets and Hamming Distance for E-Commerce Development Strategies Selection
No full textNeutrosophic sets have been recognized as an effective approach in solving complex decision-making (DM) problems, mainly when such problems are related to uncertainties, as published in numerous articles thus far. The use of the three membership functions that can be used to express accuracy, inaccuracy, and indeterminacy during the evaluation of alternatives in multiple-criteria DM can be said to be a significant advantage of these sets. By utilizing these membership functions, neutrosophic sets provide an efficient and flexible approach to the evaluation of alternatives, even if DM problems are related to uncertainty and predictions. On the other hand, the TOPSIS method is a prominent multiple-criteria decision-making method used so far to solve numerous decision-making problems, and many extensions of the TOPSIS method are proposed to enable the use of different types of fuzzy as well as neutrosophic sets. Therefore, a novel extension of the TOPSIS method adapted for the use of single-valued neutrosophic sets was considered in this paper.This article belongs to the Special Issue Symmetric and Asymmetric Data in Solution Model
Magnetic Field Measurements during Magnetic Pulse Welding Using CMR-B-Scalar Sensors
No full textThe possibility of applying CMR-B-scalar sensors made from thin manganite films exhibiting the colossal magnetoresistance effect as a fast-nondestructive method for the evaluation of the quality of the magnetic pulse welding (MPW) process is investigated in this paper. This method based on magnetic field magnitude measurements in the vicinity of the tools and joining parts was tested during the electromagnetic compression and MPW of an aluminum flyer tube with a steel parent. The testing setup used for the investigation allowed the simultaneous measurement of the flyer displacement, its velocity, and the magnitude of the magnetic field close to the flyer. The experimental results and simulations showed that, during the welding of the aluminum tube with the steel parent, the maximum magnetic field in the gap between the field shaper and the flyer is achieved much earlier than the maximum of the current pulse of the coil and that the first half-wave pulse of the magnetic field has two peaks. It was also found that the time instant of the minimum between these peaks depends on the charging energy of the capacitors and is associated with the collision of the flyer with the parent. Together with the first peak maximum and its time-position, this characteristic could be an indication of the welding quality. These results were confirmed by simultaneous measurements of the flyer displacement and velocity, as well as a numerical simulation of the magnetic field dynamics. The relationship between the peculiarities of the magnetic field pulse and the quality of the welding process is discussed. It was demonstrated that the proposed method of magnetic field measurement during magnetic pulse welding in combination with subsequent peel testing could be used as a nondestructive method for the monitoring of the quality of the welding process.This article belongs to the Special Issue Magnetic Sensors and Systems for Scientific and Industrial ApplicationsThis work was partly supported by the Research Council of Lithuania under Grant S-MIP-17-11