Vilnius Gediminas Technical University
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Statybų plėtros planavimas įvertinant trečiųjų asmenų interesus
No full textSummary of doctoral dissertationSummary of doctoral dissertatio
Satellite Laser Ranging for Retrieval of the Local Values of the Love h2 and Shida l2 Numbers for the Australian ILRS Stations
No full textThis paper deals with the analysis of local Love and Shida numbers (parameters h2 and l2) values of the Australian Yarragadee and Mount Stromlo satellite laser ranging (SLR) stations. The research was conducted based on data from the Medium Earth Orbit (MEO) satellites, LAGEOS-1 and LAGEOS-2, and Low Earth Orbit (LEO) satellites, STELLA and STARLETTE. Data from a 60-month time interval, from 01.01.2014 to 01.01.2019, was used. In the first research stage, the Love and Shida numbers values were determined separately from observations of each satellite; the obtained values of h2, l2 exhibit a high degree of compliance, and the differences do not exceed formal error values. At this stage, we found that it was not possible to determine l2 from the data of STELLA and STARLETTE. In the second research stage, we combined the satellite observations of MEO (LAGEOS-1+LAGEOS-2) and LEO (STELLA+STARLETTE) and redefined the h2, l2 parameters. The final values were adopted, and further analyses were made based on the values obtained from the combined observations. For the Yarragadee station, local h2 = 0.5756 ± 0.0005 and l2 = 0.0751 ± 0.0002 values were obtained from LAGEOS-1 + LAGEOS-2 and h2 = 0.5742 ± 0.0015 were obtained from STELLA+STARLETTE data. For the Mount Stromlo station, we obtained the local h2 = 0.5601 ± 0.0006 and l2 = 0.0637 ± 0.0003 values from LAGEOS-1+LAGEOS-2 and h2 = 0.5618 ± 0.0017 from STELLA + STARLETTE. We found discrepancies between the local parameters determined for the Yarragadee and Mount Stromlo stations and the commonly used values of the h2, l2 parameters averaged for the whole Earth (so-called global nominal parameters). The sequential equalization method was used for the analysis, which allowed to determine the minimum time interval necessary to obtain stable h2, l2 values. It turned out to be about 50 months. Additionally, we investigated the impact of the use of local values of the Love/Shida numbers on the determination of the Yarragadee and Mount Stromlo station coordinates. We proposed to determine the stations (X, Y, Z) coordinates in International Terrestrial Reference Frame 2014 (ITRF2014) in two computational versions: using global nominal h2, l2 values and local h2, l2 values calculated during this research. We found that the use of the local values of the h2, l2 parameters in the process of determining the stations coordinates influences the result.This article belongs to the Special Issue Satellite and UAV Platforms, Remote Sensing for Geographic Information SystemsThe authors would like to express their gratitude to the National Science Center, Poland (PL—Narodowe
Centrum Nauki) for the financial support for this study under Project No: 2019/03/X/ST10/01595
Modelling of Autonomous Search and Rescue Missions by Interval-Valued Neutrosophic WASPAS Framework
Get PDFThe application of autonomous robots in search and rescue missions represents a complex task which requires a robot to make robust decisions in unknown and dangerous environments. However, imprecise robot movements and small measurement errors obtained by robot sensors can have an impact on the autonomous environment exploration quality, and therefore, should be addressed while designing search and rescue (SAR) robots. In this paper, a novel frontier evaluation strategy is proposed, that address technical, economic, social, and environmental factors of the sustainable environment exploration process, and a new extension of the weighted aggregated sum product assessment (WASPAS) method, modelled under interval-valued neutrosophic sets (IVNS), is introduced for autonomous mobile robots. The general-purpose Pioneer 3-AT robot platform is applied in simulated search and rescue missions, and the conducted experimental assessment shows the proposed method efficiency in commercial and public-type building exploration. By addressing the estimated measurement errors in the initial data obtained by the robot sensors, the proposed decision-making framework provides additional reliability for comparing and ranking candidate frontiers. The interval-valued multi-criteria decision-making method combined with the proposed frontier evaluation strategy enables the robot to exhaustively explore and map smaller SAR mission environments as well as ensure robot safety and efficient energy consumption in relatively larger public-type building environments.This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/
Multiple-Criteria Decision-Making (MCDM) Techniques for Business Processes Information Management
No full textInformation management is a common paradigm in modern decision-making. A wide range of decision-making techniques have been proposed in the literature to model complex business processes. In this Special Issue, 16 selected and peer-reviewed original research articles contribute to business information management in various current real-world problems by proposing crisp or uncertain multiple-criteria decision-making (MCDM) models and techniques, mostly including multi-attribute decision-making (MADM) approaches in addition to a single paper proposing an interactive multi-objective decision-making (MODM) approach. The papers are mainly concentrated in three application areas: supplier selection and rational order allocation, the evaluation and selection of goods or facilities, and personnel selection/partner selection. A number of new approaches are proposed that are expected to attract great interest from the research community.This article belongs to the Special Issue Multiple-Criteria Decision-Making (MCDM) Techniques for Business Processes Information Managemen
An Approach for the Analysis of the Accessibility of Fire Hydrants in Urban Territories
No full textGlobally, fire causes considerable losses that can be alleviated by taking appropriate actions facilitated by systems supported by geo-information technologies. This research focuses upon the development of an approach for planning urban infrastructures, and particularly in the accessibility of fire hydrants. Accessibility of fire hydrants’ infrastructure in urban territories is one of the key elements in fire risk management and public safety. The main result of the research is a comprehensive and structured Geographic Information Systems (GISs)-based dataset for the fast and more efficient planning of fire hydrants in urban territories. The proposed framework for data collection and processing was used to determine the distribution of hydrants, location of fire brigade stations and areas and to demonstrate the capabilities of the existing municipal fire extinguishing systems in Vilnius City, Lithuania. Later on, research on fire hydrants’ accessibility, analysis of the location of protected and unprotected urban territories and marking of unprotected buildings, was carried out. The resulting map of unprotected urban territories can be of great benefit for understanding fire risks and offering more effective ways for fire risk management.This article belongs to the Special Issue Geo-Information for Developing Urban Infrastructure
Cold Chain Logistics Management of Medicine with an Integrated Multi-Criteria Decision-Making Method
No full textMedicine is the main means to reduce cancer mortality. However, some medicines face various risks during transportation and storage due to the particularity of medicines, which must be kept at a low temperature to ensure their quality. In this regard, it is of great significance to evaluate and select drug cold chain logistics suppliers from different perspectives to ensure the quality of medicines and reduce the risks of transportation and storage. To solve such a multiple criteria decision-making (MCDM) problem, this paper proposes an integrated model based on the combination of the SWARA (stepwise weight assessment ratio analysis) and CoCoSo (combined compromise solution) methods under the probabilistic linguistic environment. An adjustment coefficient is introduced to the SWARA method to derive criteria weights, and an improved CoCoSo method is proposed to determine the ranking of alternatives. The two methods are extended to the probabilistic linguistic environment to enhance the applicability of the two methods. A case study on the selection of drug cold chain logistics suppliers is presented to demonstrate the applicability of the proposed integrated MCDM model. The advantages of the proposed methods are highlighted through comparative analyses.This article belongs to the Special Issue Artificial Intelligence in Health CareThe research was funded by the National Natural Science Foundation of China under Grant 71771156,
71971145 and the APC was funded by the National Natural Science Foundation of China under Grant 71971145
Combining Monte Carlo Simulation and Bayesian Networks Methods for Assessing Completion Time of Projects under Risk
No full textIn this study, Monte Carlo simulation and Bayesian network methods are combined to present a structure for assessing the aggregated impact of risks on the completion time of a construction project. Construction projects often encounter different risks which affect and prevent their desired completion at the predicted time and budget. The probability of construction project success is increased in the case of controlling influential risks. On the other hand, interactions among risks lead to the increase of aggregated impact of risks. This fact requires paying attention to assessment and management of project aggregated risk before and during the implementation phase. The developed structure of this article considers the interactions among risks to provide an indicator for estimating the effects of risks, so that the shortage of extant models including the lack of attention to estimate the aggregated impact caused by risks and the intensifying impacts can be evaluated. Moreover, the introduced structure is implemented in an industrial case study in order to validate the model, cover the functional aspect of the problem, and explain the procedure of structure implementation in detail.This article belongs to the Special Issue Occupational Safety and Risks in Constructio
Computer Adaptive Testing Using Upper-Confidence Bound Algorithm for Formative Assessment
Get PDFThere is strong support for formative assessment inclusion in learning processes, with the main emphasis on corrective feedback for students. However, traditional testing and Computer Adaptive Testing can be problematic to implement in the classroom. Paper based tests are logistically inconvenient and are hard to personalize, and thus must be longer to accurately assess every student in the classroom. Computer Adaptive Testing can mitigate these problems by making use of Multi-Dimensional Item Response Theory at cost of introducing several new problems, most problematic of which are the greater test creation complexity, because of the necessity of question pool calibration, and the debatable premise that different questions measure one common latent trait. In this paper a new approach of modelling formative assessment as a Multi-Armed bandit problem is proposed and solved using Upper-Confidence Bound algorithm. The method in combination with e-learning paradigm has the potential to mitigate such problems as question item calibration and lengthy tests, while providing accurate formative assessment feedback for students. A number of simulation and empirical data experiments (with 104 students) are carried out to explore and measure the potential of this application with positive results.This article belongs to the Special Issue Smart Learnin
Effect of Compaction and Hydraulic Gradient on Subbase Layer Permeability
No full textIn order to prevent or at least reduce the deformation of road surface, it is necessary to ensure adequate water permeability of the structural layers and control of groundwater level. In geotechnical engineering, the water permeability of the mineral aggregates or soils is determined using a constant head water permeability apparatus. In order to assess the suitability of the results, it is necessary to take into account particle size distribution of the test object and perform the test at different hydraulic ramps. The aim of this research is to define and clarify unbound mineral aggregate mixtures hydraulic gradient and compaction level of road layer impact on water permeability. The following properties have been determined during the tests: particle size distribution, particle density, Proctor density, optimum water quantity, water permeability under different compaction and hydraulic slopes. Based on the results of the research, low-dustiness non-bonded mineral materials are recommended for frost resistant layers. For the water-permeability coefficient test, it is recommended that the test layer should be compacted to a design compaction ratio and the hydraulic gradient should not be higher than 1.0. Other conclusions and recommendations for further research and for improvement of water permeability functionality in the road pavement are presented.This article belongs to the Special Issue Pavement Surface Coating
Investigation of Piezoelectric Ringing Frequency Response of Beta Barium Borate Crystals
No full textThe piezoelectric ringing phenomenon in Pockels cells based on the beta barium borate crystals was analyzed in this work. The investigation results show that piezoelectric ringing is caused by multiple high voltage pulses with a frequency in the range from 10 kHz up to 1 MHz. Experimental investigation of frequency response and Discrete Fourier transformation was used for analysis. The method of piezoelectric ringing investigation based on the analysis of difference of real and simulated optical signals spectrums was proposed. The investigations were performed for crystals with 3 × 3 × 25 mm, 4 × 4 × 25 mm and 4 × 4 × 20 mm dimensions. It was estimated that piezoelectric ringing in the beta barium borate crystal with dimensions of 3 × 3 mm × 25 mm occurred at the 150, 205, 445, 600 and 750 kHz frequencies of high voltage pulses.This article belongs to the Special Issue Crystal Growth of Multifunctional Borates and Related Material