2020 - Publications Repository - Gdańsk University of Technology

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ESPAR Antenna-Based WSN Node With DoA Estimation Capability
- Mateusz Groth
- Mateusz Rzymowski
- Krzysztof Nyka
- Łukasz Kulas
2020 Full text IEEE Access
In this paper, we present a low-cost energy-efficient electronically steerable parasitic array radiator (ESPAR) antenna-based wireless sensor network (WSN) node designed for IEEE 802.15.4 standard that is capable of performing direction of arrival (DoA) estimation in real-life outdoor environments. To this end, we propose the WSN node architecture, design and realization that utilizes NXP JN5168 radio frequency (RF) wireless transceiver and a microcontroller integrated with ESPAR antenna beam-switching circuits. To incorporate DoA estimation capability into the developed single-board WSN node, power-pattern cross-correlation (PPCC) algorithm, that relies solely on received signal strength (RSS) values measured by the transceiver at the antenna output for every considered directional antenna radiation pattern, has been adapted and implemented in a simple microcontroller embedded within NXP JN5168 integrated circuit. Measurements conducted in an outdoor environment show that the proposed low-cost WSN node can successfully provide DoA estimation results, which may be used to enhance WSN capabilities in practical applications. The obtained root mean square (RMS) DoA estimation errors are 7.91°, 6.58° and 9.47° for distances between WSN nodes equal to 3 m , 5 m and 10 m respectively.
Esselunga
- Luciano Segreto
2020
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Estimating the Cost of Cybersecurity Activities with CAsPeA: A Case Study and Comparative Analysis
- Rafał Leszczyna
- Adrian Litwin
2020 Full text
Contemporary approaches to the estimation of cybersecurity costs in organisations tend to focus on the cost of incidents or technological investments. However, there are other, less transparent costs related to cybersecurity management that need to be properly recognised in order to get a complete picture. These costs are associated with everyday activities and the time spent by employees on cybersecurity-related actions. Such costs constitute a substantial component of cybersecurity expenditures, but because they become evident only during scrupulous analyses, often they are neglected. This paper presents new developments on CAsPeA - a method which enables estimating the cost of these activities based on a model derived from the Activity-Based Costing (ABC) and the NIST SP 800-53 guidelines. The application of the method is illustrated by a case study of a civil engineering enterprise. The method's evaluation based on comparative analysis in respect to SQUARE is described.
Estimating the parameter of inequality aversion on the basis of a parametric distribution of incomes
- Stanisław Kot
2020 Full text EQUILIBRIUM Quarterly Journal of Economics and Economic Policy
Research background: In applied welfare economics, the constant relative inequality aversion function is routinely used as the model of a social decisionmaker’s or a society’s preferences over income distributions. This function is entirely determined by the parameter, ε, of inequality aversion. However, there is no authoritative answer to the question of what the range of ε an analyst should select for empirical work. Purpose of the article: The aim of this paper is elaborating the method of deriving ε from a parametric distribution of disposable incomes. Methods: We assume that households’ disposable incomes obey the generalised beta distribution of the second kind GB2(a,b,p,q). We have proved that, under this assumption, the social welfare function exists if and only if ε belongs to (0,ap+1) interval. The midpoint εmid of this interval specifies the inequality aversion of the median social-decisionmaker. Findings & Value added: The maximum likelihood estimator of εmid has been developed. Inequality aversion for Poland 1998–2015 has been estimated. If inequality is calculated on the basis of disposable incomes, the standard inequality–development relationship might be complemented by inequality aversion. The “augmented” inequality–development relationship reveals new phenomena; for instance, the stage of economic development might matter when assessing the impact of inequality aversion on income inequality.
Estimating the uncertainty of discharge coefficient predicted for oblique side weir using Monte Carlo method
- Ahmed Y. Mohammed
- Anna Golijanek-Jędrzejczyk
2020 Full text FLOW MEASUREMENT AND INSTRUMENTATION
Side weir is a hydraulic structure, which is used in irrigation systems to divert some water from main to side channel. It is installed at the entrance of the side channel to control and measure passing water into the side channel. Many studies provided side weir water surface profile and coefficient of discharge to measure water discharge diverted into the side channel. These studies dealt with different side weir shapes (rectangular, trapezoidal, triangular and circular), which were installed perpendicular to the flow direction. Recently, some studies dealt with skew side weir, but these studies still need to more investigation. Here we report to investigate oblique side weir theoretically using statistical method to supported other studies in this case. Measurement uncertainty discharge coefficient Cd was obtained by two methods: analytical according to the 'Guide to the expression of uncertainty in measurement' and the Monte Carlo method. The results indicate that all experimental results are consistent with the analytical results. The relative expanded uncertainty of the discharge coefficient Cd does not exceed 2%.
Estimation and Prediction of Vertical Deformations of Random Surfaces, Applying the Total Least Squares Collocation Method
- Zbigniew Wiśniewski
- Waldemar Kamiński
2020 Full text SENSORS
This paper proposes a method for determining the vertical deformations treated as random fields. It is assumed that the monitored surfaces are subject not only to deterministic deformations, but also to random fluctuations. Furthermore, the existence of random noise coming from surface’s vibrations is also assumed. Such noise disturbs the deformation’s functional models. Surface monitoring with the use of the geodetic levelling network of a free control network class is carried out. Assuming that, in some cases, the control networks are insufficient in surface’s deformation analysis, additional and non–measurable reference points have been provided. The prediction of these points’ displacements and estimation of the free control network points’ displacement are carried out using the collocation method applying the total least squares adjustment. The proposed theoretical solutions were verified by the simulation methods and on the example of a real control network
Estimation of Broadband Complex Permeability Using SIW Cavity-Based Multimodal Approach
- Nilesh K. Tiwari
- Abhishek Jha
- Surya P. Singh
- M. Jaleel Akhtar
2020 Full text IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
In this article, an attractive multimodal substrate integrated waveguide (SIW) based methodology is presented for the characterization of magnetic materials in the broadband microwave frequency. The proposed approach employs a modified feed under-coupled SIW cavity instead of conventional feed over-coupled multiple SIW cavities; it uses the modified closedform expression, developed from the first principle to consider the effect of finite sample dimensions, and mode-specific sinusoidal field variations, which were not considered before for magnetic testing using the over-coupled SIW cavity and conventional formulations. The metallic cavity borne approximations i.e., very small frequency shift for the imaginary part calculation, and very high Q-factor for the real permeability estimation are also relaxed in the modified formulations. The proposed technique is numerically verified using the full-wave electromagnetic (EM) simulator for several dispersive and nondispersive standard samples; thereafter, it is validated for the estimation of complex permeability of synthesized dispersive magnetic composites. It can characterize the dispersive magnetic composites, where the permeability value varies from paramagnetic to diamagnetic range, with improved accuracy than that of the conventional cavity perturbation approach. The modified formulation provides 34% and 12% better estimation of loss tangent and real permeability, respectively, as compared with the conventional technique. The uncertainty analysis for change in sample volume, sample misalignment, and the possible air gap is also carried out in detail. The proposed scheme typically provides more than 92% and 84% accuracy in the measured values of real permeability and loss tangent data, respectively, for various synthesized magnetic samples in broadband of microwave frequency (10–22 GHz).
Etapy projektowania statków oraz przepływ dokumentacji
- Dominik Kreft
2020 Full text Journal of Polish CIMEEAC
W artykule przedstawiono główne etapy projektu okrętowego wg. różnych autorów. Następnie opisano zakres prac dla każdego z etapów i przedstawiono je w postaci spirali projektowej. Przedstawiono i opisano również schemat przepływu dokumentacji podczas realizacji projektu klasyfikacyjnego z wyszczególnieniem armatora, biura projektowego, stoczni oraz towarzystwa klasyfikacyjnego.
Evaluating calibration and robustness of pedestrian detectors
- Sebastian Cygert
- Andrzej Czyżewski
2020
In this work robustness and calibration of modern pedestrian detectors are evaluated. Pedestrian detection is a crucial perception com- ponent in autonomous driving and here we study its performance under different image corruptions. Furthermore, we provide analysis of classifi- cation calibration of pedestrian detectors and we show a positive effect of using style-transfer augmentation technique. Our analysis is aimed as a step towards understanding and improving current safety-critical detection systems.
Evaluating the Cost of Personnel Activities in Cybersecurity Management: A Case Study
- Rafał Leszczyna
2020 Full text
The methods of cybersecurity costs' evaluation are inclined towards the cost of incidents or technological acquirements. At the same time, there are other, less visible costs related to cybersecurity that require proper recognition. These costs are associated with the actions and the time spent by employees on activities connected to cybersecurity management. The costs form a considerable component of cybersecurity expenditures, but because they become evident only during scrupulous analyses, often they are disregarded. CAsPeA is a method that enables estimating the costs based on a model derived from the Activity-Based Costing (ABC) and the NIST SP 800-53 guidelines. This paper presents the application of CAsPeA in a steel structures manufacturing company.
Evaluation of a company’s image on social media using the Net Sentiment Rate
- Anna Baj-Rogowska
2020
Vast amounts of new types of data are constantly being created as a result of dynamic digitization in all areas of our lives. One of the most important and valuable categories for business is data from social networks such as Facebook. Feedback resulting from the sharing of thoughts and emotions, expressed in comments on various products and services, is becoming the key factor on which modern business is based. This feedback is called sentiment on social media. The sentiment analysis method is used for the mining of polarity views, feelings and emotions from text data with the help of natural language processing (NLP). The fundamental task in this technique is to classify the polarity of opinions into classes such as positive, negative and neutral. This chapter introduces a novel approach to the quantitative measurement of sentiment by means of a created indicator called the Net Sentiment Rate (NSR). The proposed NSR expresses the net sentiment extracted from text data and provides values on a scale from -1 to +1. The Net Sentiment Rate implementation has been verified on large datasets crawled from Facebook in the period from 1 October 2014 to 31 December 2018, for three international companies from the same sector. The created Net Sentiment Rate, together with the classification of its strength, and its verification, constitutes the contribution of this study.
Evaluation of Foundation Input Motions Based on Kinematic Interaction Models
- Tomasz Falborski
2020
The present study was designed to demonstrate the importance of baseslab averaging and embedment effects on the foundation-level input motions due to earthquake excitations. Evaluation of foundation-level input motions based on the most commonly adopted kinematic interaction models are presented. In order to conduct this investigation, original records of horizontal accelerations for two casestudy buildings were utilized. Computed foundation-level input motions, in both NS and EW directions, were compared to the actual acceleration-time histories recorded at the foundation levels. The results clearly indicate that incorporating base-slab averaging and embedment effects in seismic analyses can modify the dynamic excitation imposed at the foundation level, and, as a consequence, lead to more accurate structural response due to earthquake ground motions.
Evaluation of Immobilization of Selected Peat-Isolated Yeast Strains of the Species Candida albicans and Candida subhashii on the Surface of Artificial Support Materials Used for Biotrickling Filtration
- Milena Marycz
- Anna Brillowska-Dąbrowska
- Jacek Gębicki
2020 Full text Processes
The paper describes the process of n-butanol abatement by unicellular fungi, able to deplete n-butanol content in gas, by using n-butanol as source of carbon. Isolated and identified fungi species Candida albicans and Candida subhashii were subjected to a viability process via assimilation of carbon from hydrophilic and hydrophobic compounds. The isolates, which exhibited the ability to assimilate carbon, were immobilized on four different types of artificial support materials used for biotrickling filtration. Application of optical microscopy, flow cytometry and the tests employing propidium iodide and annexin V revealed viability of the fungi isolated on support materials’ surfaces at the average level of 95%. The proposed method of immobilization and its evaluation appeared to be effective, cheap and fast. Based on performed comparative analyses, it was shown that polyurethane foam and Bialecki rings (25 × 25) could be attractive support materials in biotrickling filtration.
Evaluation of Lombard Speech Models in the Context of Speech in Noise Enhancement
- Grazina Korvel
- Krzysztof Kąkol
- Olga Kurasova
- Bożena Kostek
2020 Full text IEEE Access
The Lombard effect is one of the most well-known effects of noise on speech production. Speech with the Lombard effect is more easily recognizable in noisy environments than normal natural speech. Our previous investigations showed that speech synthesis models might retain Lombard-effect characteristics. In this study, we investigate several speech models, such as harmonic, source-filter, and sinusoidal, applied to Lombard speech in the context of speech enhancement. For this purpose, 100 utterances of natural speech, and 100 with the Lombard effect induced are used. The goal of this study is to check to what extent speech utterances based on these models are recognizable and at what SNR (Signal-to-Noise Ratio) level threshold a particular model stops working. For this purpose, the synthesized models and Lombard speech are mixed with babble speech and street noise recordings with different SNRs. The quality of these models is measured, employing objective indicators as well as subjective tests. Since there is no standardized measure to apply to enhanced speech, an objective measure of assessing the speech quality of a model synthesizing Lombard speech characteristics, based on a feature vector, is proposed. Our approach is then compared with the standardized metric used in telecommunications as well as with subjective test results. The experimental investigations show the superiority of the source-filter models applied to synthesize Lombard speech over other models utilized. Also, the measure proposed correlates more closely with the results of the subjective evaluation than the outcomes from the ITU-T P.563 recommendation. This was checked with a ANOVA statistical analysis.
Evaluation of Mechanical Properties of Two-Stage Concrete and Conventional Concrete Using Nondestructive Tests
- Ali M. Rajabi
- Farzam Omidimoaf
- Hakim Abdelgader
2020 Full text JOURNAL OF MATERIALS IN CIVIL ENGINEERING
Different types of concrete mixtures are used as building materials. The manufacturing process of two-stage concrete (TSC) differs from that of conventional concrete. This study investigated conventional mechanical properties derive empirical relations for estimation of the mechanical parameters of TSC and conventional concrete mixtures. TSC was used to prepare 216 specimens and conventional concrete was used to prepare 108 specimens that then were aged for 28 days. Uniaxial compression, Brazilian tensile strength, and point load tests were carried out as destructive testing. Schmidt hammer and ultrasonic pulse velocity tests were carried out as nondestructive testing. The data from testing were categorized as regression or test data. Empirical relations were derived between the parameters for the two types of concrete, and these relations were validated. It was concluded that indirect, nondestructive testing of engineering materials, including concrete, considerably increases the speed and decreases the estimation cost of determining the mechanical parameters. This method can be recommended for estimation of these mechanical parameters.
Evaluation of Selected UX Techniques by Product Managers - A Preliminary Survey
- Jakub Miler
- Margarita Menjega-Schmidt
2020
In this paper we present the results of an opinion survey among 28 IT product managers who evaluated the subjective usefulness of 24 selected UX techniques to 6 IT product management tasks derived from ProdBOK®. We selected the UX techniques based on the literature review and 6 interviews with experienced IT product managers. Based on the survey results, we propose our recommendation of useful techniques for 5 of the 6 studied IT product management tasks. Additionally, we report on the overall perceived usefulness of the UX techniques to all affected IT product management tasks.
Evaluation of the Greenness of Analytical Procedures
- Marta Bystrzanowska
- Jacek Namieśnik
- Marek Tobiszewski
2020
This contributions introduces the need to develop the methods to evaluate analytical procedures in the light of green analytical chemistry. Green chemistry metrics are not applicable in analytical chemistry because they refer to the mass of product and no product with mass is generated during analytical determination. Analytical greenness evaluations are based on scoring - such as NEMI or Eco-scale or comparative analysis as it is in case of multicriteria decision analysis. Important aspect is also the assessment of solvents and reagents that are applied in analytical procedures for their greening. The different environmental, safety and health parameters are included in the assessments of solvents and reagents. The contribution presents the mechanisms of evaluation and numerous examples. Some results of reagents and solvents assessments are also presented to help analysts in selection greener alternatives.
Evaluation of the Influence of Farming Practices and Land Use on Groundwater Resources in a Coastal Multi-Aquifer System in Puck Region (Northern Poland)
- Adam Szymkiewicz
- Dawid Potrykus
- Beata Jaworska-Szulc
- Anna Gumuła-Kawęcka
- Małgorzata Pruszkowska-Caceres
- Lidia Dzierzbicka-Głowacka
2020 Full text Water
This study focuses on the modeling of groundwater flow and nitrate transport in a multi-aquifer hydrosystem in northern Poland, adjacent to Puck Bay (Baltic sea). The main goal was to investigate how changes in land use and farming practices may affect groundwater recharge and submarine groundwater discharge (SGD) to the sea and the associated N-NO3 fluxes. An integrated modelling approach has been developed, which couples the SWAT hydrologic model, MODFLOW-NWT groundwater flow model, and MT3DMS transport model. Transient simulations were performed for a 10 y period, assuming 10 different scenarios of land use (farming, grassland, forest) and crop types. Both recharge and SGD showed a distinct pattern of seasonal time variability. In terms of the average flow rates, the effect of varying crop type was more significant than that of land use change, with the minimum recharge and SGD corresponding to winter wheat and the maximum for peas and potatoes. Nitrate loads were strongly affected by both land use and crop type, with minimum values obtained for grassland and maximum values for canola.
EVALUATION OF THE NO2CONCENTRATION PREDICTION POSSIBILITYBASED ON STATIC AND DYNAMIC RESPONSES OF TGS SENSORSAT CHANGING HUMIDITY LEVELS
- Paweł Kalinowski
- Łukasz Woźniak
- Grzegorz Jasiński
- Piotr Jasiński
2020 Full text Metrology and Measurement Systems
The commercially available metal-oxide TGS sensors are widely used in many applications due to thefact that they are inexpensive and considered to be reliable. However, they are partially selective and theirresponses are influenced by various factors,e.g. temperature or humidity level. Therefore, it is importanttodesign a proper analysis system of the sensor responses. In this paper, the results of examinations of eightcommercial TGS sensors combined in an array and measured over a period of a few months for the purposeof prediction of nitrogen dioxide concentration are presented. The measurements were performed at differentrelative humidity levels. PLS regression was employed as a method of quantitative analysis of the obtainedsensor responses. The results of NO2concentration prediction based on static and dynamic responses ofsensors are compared. It is demonstrated that it is possibleto predict the nitrogen dioxide concentrationdespite the influence of humidity
Evaluation of the Possibility of Identifying a Complex Polygonal Tram Track Layout Using Multiple Satellite Measurements
- Andrzej Wilk
- Cezary Specht
- Władysław Koc
- Krzysztof Karwowski
- Jacek Skibicki
- Jacek Szmagliński
- Piotr Chrostowski
- Pawel S. Dabrowski
- Mariusz Specht
- Marek Zienkiewicz
- Sławomir Judek
- Marcin Skóra
- Sławomir Grulkowski
2020 Full text SENSORS
We present the main assumptions about the algorithmization of the analysis of measurement data recorded in mobile satellite measurements. The research team from the Gda´nsk University of Technology and the Maritime University in Gdynia, as part of a research project conducted in cooperation with PKP PLK (Polish Railway Infrastructure Manager), developed algorithms supporting the identification and assessment of track axis layout. This article presents selected issues concerning the identification of a tramway line’s axis system. For this purpose, the supporting algorithm was developed and measurement data recorded using Global Navigation Satellite System (GNSS) techniques was evaluated and analyzed. The discussed algorithm identifies main track directions from multi-device data and repeated position recordings. In order to observe the influence of crucial factors, the investigated route was carefully selected. The chosen tramway track was characterized by its location in various field conditions and a diversified and complex geometric layout. The analysis of the obtained results was focused on the assessment of the signal’s dispersion and repeatability using residuals in relation to the estimated track’s direction. The presented methodology is intended to support railway infrastructure management processes, mainly in planning and maintenance through an effcient inventory of the infrastructure in service.