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Polarization-dependent optical absorption in phosphorene flakes
PublicationThe interest of 2D materials is constantly increasing because of their very attractive mechanical, electrical and optical parameters. They have been used in many applications, e.g. photodetectors, sensors, modulators, insulators. One of the recently discovered 2D materials is phosphorene. In contrast to graphene, phosphorene has a direct bandgap tuned by numbers of layers in the 2D structure. The phosphorene flakes are strongly...
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Valuation of architectural heritage by multicultural student groups
PublicationIn this article, the author addresses the education of architecture students in the field of architectural history and the determination of the value of architectural objects. Important changes at present are underway concerning this. Both the role of architectural history in architectural education and content in architectural history curricula is changing. The need for re-evaluation...
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Geotechnical characterization of soft soil deposits in Northern Poland
PublicationThis paper presents a geotechnical characterization of deltaic soft soil deposits in the Vistula Marshlands, northern Poland. It shows the limited applicability of organic soil classifications based on Cone Penetration Tests (CPTU) and Dilatometer Tests (DMT). None of the in-situ-based classifications correctly identifies peat. Analysis of the behaviour of contractive/dilative soil layers according to Robertson's updated classification...
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Analysis of the Application of Horizontal Directional Drilling
PublicationConstruction works are often considered to be very intrusive for the environment. Project designers assume deep excavations, or a complete replacement of the ground within the investment, which sometimes changes the initial conditions drastically. The problem started to appear in places, where the terrain is complicated and the excavation is burdensome. Some of state authorities...
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The CFD analysis of influence the start of fuel injection (SOI) on combustion parameters and exhaust gas composition of the marine 4-stroke engine
PublicationThe paper presents a theoretical analysis of the impact of injection timing on the parameters of the combustion process and the composition of exhaust gas from a 4-stroke engine designed to shipbuilding. The analysis was carried out based on a three-dimensional multi-zone model of the combustion process. This model has been prepared on the basis of properties of the research facility. The input data to the model were obtained through...
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Determination of the dynamic critical maneuvering area in an encounter between two vessels: Operation with negligible environmental disruption
PublicationThis paper introduces the concept of Collision Avoidance Dynamic Critical Area (CADCA) for onboard Decision Support Systems (DSS). The indicator proposed is derived via identification of a minimum required maneuvering zone in an encounter between two vessels. The CADCA model accounts for ship maneuvering dynamics and associated hydrodynamic actions emerging from different rudder angles and forward speed effects. The method presented...
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Task Scheduling – Review of Algorithms and Analysis of Potential Use in a Biological Wastewater Treatment Plant
PublicationThe idea of task scheduling is to increase the efficiency of a system by minimising wasted time, evenly loading machines, or maximising the throughput of machines. Moreover, the use of appropriate scheduling algorithms often leads to a reduction in the energy costs of the process. Task scheduling problems are found in a variety of industrial areas, and their scale changes significantly depending on the problem. This review shows...
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Use of ICT infrastructure for teaching HPC
PublicationIn this paper we look at modern ICT infrastructure as well as curriculum used for conducting a contemporary course on high performance computing taught over several years at the Faculty of Electronics Telecommunications and Informatics, Gdansk University of Technology, Poland. We describe the infrastructure in the context of teaching parallel programming at the cluster level using MPI, node level using OpenMP and CUDA. We present...
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Wood Moisture-Content Measurement Accuracy of Impregnated and Nonimpregnated Wood
PublicationThe influence of the impregnation process of pine wood (Pinus sylvestris L.) samples on the electrical resistance changes and the moisture-content measurement accuracy is presented in this paper. In this study, the resistances of impregnated and nonimpregnated green pine timber harvested from northern Poland were compared. An impregnation method based on a vacuum-pressure chamber was used. Copper salts were applied as the impregnated...
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Studies on Aminoanthraquinone-Modified Glassy Carbon Electrode: Synthesis and Electrochemical Performance toward Oxygen Reduction
PublicationIn this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were studied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation...
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Experimental study of the use of electric car powered with stationary solar and electrochemical batteries in Northern Poland
PublicationThe subject of this paper is an experimental analysis of a Nissan LEAF electric car equipped with 24 kWh battery, powered from the standalone photo-voltaic (PV) charging station in Gdańsk, Poland. The calculations of charging process efficiency and range of test drives were conducted in two extreme situations (winter and summer) of sunlight and road conditions. Experiments were performed in the Laboratory of Innovative Power Technologies...
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Safety Assessment of the Regional Warmia and Mazury Road Network Using Time-Series Analysis
PublicationWarmia and Mazury still belongs to the areas with the smallest transport accessibility in Europe. Unsatisfactory state of road infrastructure is a major barrier to the development of the regional economy, impacting negatively on the life conditions of the population. Also in terms of road safety Warmia and Mazury is one of the most endangered regions in Poland. The Police statistics show that beside a high pedestrian risk observed...
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E-learning in tourism and hospitality: A map
PublicationThe impact of information and communication technologies (ICT) on tourism and hospitality industries has been widely recognized and investigated as a one of the major changes within the domains in the last decade: new ways of communicating with prospective tourists and new ways of purchasing products arisen are now part of the industries’ everyday life. Poor attention has been paid so far to the role played by new media in education...
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Preliminary studies on the effect of feed speed on the colour change of wood
PublicationThis paper presents the results of preliminary analyses of the effect of cutting parameters on changes in the colour of wood. Beech wood cut with use circular saw was analysed. The cutting parameter tested was the feed speed, represented by the feed per tooth. Sawing processes with different feed per tooth ranging from 0.0008 mm to 0.09 mm were analysed. It was observed that over the entire range of feed rate per tooth analysed,...
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Displacement Sensors Based on the Phase of the Reflection Coefficient of a Split Ring Resonator Loaded Transmission Line
Publication— In this paper, novel displacement sensors using a microstrip loaded with a pair of split ring resonators (SRRs) are proposed. It is shown that the phase of the reflection coefficient from the loading SRRs can be used for displacement sensing. The paper also proposes a differential version of the sensor that benefits from a higher sensitivity and reference zero, which is useful for alignment purposes. It is further shown that...
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Tripping of F-type RCDs for sinusoidal residual current with superimposed smooth DC component
PublicationRecent trends in green energy development make that photovoltaics and electric vehicles are applied on an increasing scale. In both photovoltaic and electric vehicle charging installations, a significant value of DC component of the earth fault current may appear, which is a challenge, in particular, for commonly used residual current devices (RCDs). This paper presents results of the laboratory test on the operation of F-type...
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Improving Objective Speech Quality Indicators in Noise Conditions
PublicationThis work aims at modifying speech signal samples and test them with objective speech quality indicators after mixing the original signals with noise or with an interfering signal. Modifications that are applied to the signal are related to the Lombard speech characteristics, i.e., pitch shifting, utterance duration changes, vocal tract scaling, manipulation of formants. A set of words and sentences in Polish, recorded in silence,...
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The Use of Unmanned Surface Vessels in Bathymetric Measurements of Waterbodies with Highly Dynamic Seafloor Relief
PublicationThe early 21st century is a time when unmanned surface vessels (USV) are used in various measurement applications. Modern autonomous and unmanned vessels are increasingly often used in bathymetric measurements whose aim is to measure the seafloor with the sufficient positioning accuracy. Therefore, the use of USVs in hydrography can be seen as the beginning of a new era in this regard. This paper presents bathymetric measurements...
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Structure-Property Relationship and Multiple Processing Studies of Novel Bio-Based Thermoplastic Polyurethane Elastomers
PublicationCurrently, the growing demand for polymeric materials has led to an increased need to develop effective recycling methods. This study focuses on the multiple processing of bio-based thermoplastic polyurethane elastomers (bio-TPUs) as a sustainable approach for polymeric waste management through mechanical recycling. The main objective is to investigate the influence of two reprocessing cycles on selected properties of bio-TPUs....
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Why the solvation water around proteins is more dense than bulk water
PublicationThe main aim of this work is to propose a rational explanation of commonly observed phenomenon of increasing water density within solvation shell of proteins. We have observed that geometry of the water-water hydrogen bond network within solvation layer differs from the one in bulk water and it is the effect of interactions of water molecules with protein surface. Altered geometry of the network reflects changes in the structure...
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Investigation of noises in the EPN weekly time series
PublicationThe constantly growing needs of permanent stati ons’ velocities users cause their stability level to increase. To this research we included more than 150 stations located across Europe operating within the EUREF Permanent Network (EPN) w ith weekly changes in the ITRF2005 reference frame. The obvious long-range dependencies in the stochastic part of GPS time series were p roven by Ljung-Box...
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Why the Solvation Water around Proteins Is More Dense than Bulk Water
PublicationThe main aim of this work is to propose a rational explanation of the commonly observed phenomenon of increasing water density within solvation shell of proteins. We have observed that the geometry of the water–water hydrogen bond network within solvation layer differs from the one in bulk water, and it is the result of interactions of water molecules with protein surface. Altered geometry of the network reflects changes in the...
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NUMERICAL MODEL QUALITY ASSESSMENT OF OFFSHORE WIND TURBINE SUPPORTING STRUCTURE BASED ON EXPERIMENTAL DATA
PublicationAs a structure degrades some changes in its dynamical behavior can be observed, and inversely, observation and evaluation of these dynamical changes of the structure can provide information of structural state of the object. Testing of the real structure, besides of being costly, can cover only limited working states. It is particularly considerable in case of hardly accessible, and randomly/severely dynamically loaded offshore...
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The Impact of Isocyanate Index and Filler Functionalities on the Performance of Flexible Foamed Polyurethane/Ground Tire Rubber Composites
PublicationThe structure and performance of polyurethane (PU) foams are strongly driven by the stoichiometry of the polyaddition reaction, quantitatively described by the isocyanate index. It determines the balance between isocyanate and hydroxyl groups in the reacting system and is affected by the introduction of additional functionalities originated, e.g., from applied fillers. Nevertheless, this issue is hardly taken into account in research...
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Systematic review examining the evidence for impact of school policies on physical activity
PublicationBackground Epidemiological evidence has demonstrated that physical activity can have substantive health benefits for children and young people. The 'Policy Evaluation Network' is a multi-disciplinary research network across 7 European countries and New Zealand aimed at building capacity and evaluating the level of impact of policy interventions for promoting healthy lifestyles. The Toronto Charter identified 'whole-of-school' programmes...
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Healthy financial system of local government on the example of Poland
Publicationhealthy local government financial system lays the foundation for the ability of local government units (LGUs) to carry out public tasks at the current qualitative and quantitative level and to meet their obligations in the short and long term. A healthy financial system of local government is a system that is adequate, stable, unified, consistent, transparent, diversified, counter-cyclical, guarantees the financial independence...
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AC-DC-DC Converter for Small Power Energy Storage Systems
PublicationThe energy transformation driven by the development of renewable energy sources has become a reality for all power grid users. Prosumer energy, primarily utilizing photovoltaic installations, is one of the fastest-growing market segments. The advancement of technology, a decrease in electrochemical energy storage prices, and changes in the legal framework governing energy billing for grid-fed power have led to a growing interest...
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Effect of Storage Conditions of Rutile Flux Cored Welding Wires on Properties of Welds
PublicationThe influence of storage locations of two grades of rutile flux cored welding wires on their surface condition and the strength of the welds made with them were studied. Wires were stored in real urban conditions (Gdańsk and Katowice) for 1 month, simultaneously recording changes in conditions: temperature and relative humidity of the environment. Visual tests of wires in the delivered and stored condition as well as visual and...
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Study on population dynamics for triple-linked food chain using a simulation-based approach
PublicationThe procedures based on simulation have become a feasible testing method that does not require investing valuable resources to create a concrete prototype, especially with the increasing computational power of computers. Thus, design changes can be adopted and design errors can be fixed before it is too late. Simulation turns to be a cheap, safe and often more acceptable from an ethical perspective. In our work we summarize the...
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Pseudo-superparamagnetic behaviour of bariumhexaferrite particles
PublicationThe effect of hexadecyltrimethylammonium bromide (CTAB) addition on the crystal structure, morphology,and magnetic properties of co-precipitated hexagonal barium ferrite was investigated. For afixed amount ofsurfactant, different Fe3+concentrations and Fe3+/Ba2+ratios were used to optimize the formation ofsingle-phase barium ferrite particles. The results indicated that the obtained ferrite particles exhibitedcoercivity changes...
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Leveraging Generative AI Tools for UX Design in Lean and Agile Projects
PublicationRecent advancements in Generative AI (GenAI) open new opportunities to improve User Experience (UX) practitioners’ efficiency in their projects. Due to intensive teamwork caused by time pressure and readiness for rapid changes, Lean and Agile project management seems particularly predestined for easy adoption of GenAI-supported UX design methods. However, precipitate and spontaneous leveraging of GenAI tools to UX design bears...
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Adaptive prediction of stock exchange indices by state space wavelet networks
PublicationThe paper considers the forecasting of the Warsaw Stock Exchange price index WIG20 by applying a state space wavelet network model of the index price. The approach can be applied to the development of tools for predicting changes of other economic indicators, especially stock exchange indices. The paper presents a general state space wavelet network model and the underlying principles. The model is applied to produce one session...
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Dynamics of productivity in higher education: cross-european evidence based on bootstrapped Malmquist indices
PublicationAbstract This study examines patterns of productivitychange in a large set of 266 public higher educationinstitutions (HEIs) in 7 European countries across the timeperiod 2001-2005. We adopt consistent bootstrap estimationprocedures to obtain confidence intervals for Malmquistindices of HEI productivity and their components.Consequently, we are able to assess the statistical significanceof changes in HEI productivity, efficiency...
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Factors disturbing Internet usage in opinion of elderly users
PublicationInternet became truly widespread in modern societies. This created its huge economic potential, which is widely used, especially in traditionally communication-oriented societies like USA and Scandinavian countries. This trend enables to create economic growth even despite of worldwide economic slowdown.Together with demographic changes this raise the necessity of research on how older users perceive modern, Internet-based tools...
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Structural and luminescence investigation of GeO2-PbO-Bi2O3-SrF2 glasses doped with Eu3+, Tb3+ and Tm3+ ions
PublicationThe GeO2-PbO-Bi2O3-SrF2 (GePbBiSr) glass systems doped with Eu3 +, Tb3 +, Tm3 + and triply-doped with Eu3 +/Tb3 +/Tm3 + ions were successfully synthesized. Their structural and luminescent properties have been investigated with various techniques. Obtained results indicate that these glass systems are suitable materials for the RE3 + ions hosts. RE3 + ions can be excited by single UV light wavelength (355/378/395 nm) and simultaneously...
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Use of radiography images and gray level co-occurrence matrix to investigate gravitational granular flow
PublicationThe paper presents analysis of granular gravitational flow based on radiography images processing. The investigations were conducted for silo model geometry with concentric/eccentric discharging modes. The continuous X-ray radiography scans of granular material distribution, acquired during flow, were obtained by means of an especially designed model silo with rectangular bin and different settings of hopper angles. Image processing...
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The influence of historical conditions on time and cost of construction project
PublicationConducting construction works in a building or in an area entered in the historic register is associated with the contracting authority's risk of incurring higher than planned costs of works, as well as delays in their implementation. In many cases, these deviations are completely independent of contracting authority and contractor. The aim of this article is to indicate the reasons for cost and time changes in the construction...
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Composites of tin oxide and different carbonaceous materials as negative electrodes in lithium-ion batteries
PublicationAbstract Tin and tin oxide have been considered as suitable materials with high theoretical capacity for lithium ion batteries. Their low cost, high safety and other technical benefits placed them as promising replacements for graphite negative electrodes. The problem to overcome with tin oxide, as well as with other metallic materials, is high volume changes during alloying/dealloying, subsequent pulverization, delamination from...
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Studies on Aminoanthraquinone-Modified Glassy Carbon Electrode: Synthesis and Electrochemical Performance toward Oxygen Reduction
PublicationIn this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes werestudied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation...
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Does one currency mean one price?
PublicationEuropean Monetary Union was expected to have many consequences for the economies of participant countries. Theory suggested that through a higher volume of trade and stronger competition in the Eurozone, a single currency would lead to a reduction in price dispersion. As far as prices are concerned, two effects were expected: an immediate effect due to the technical characteristics of the changeover process, and a long-term one...
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Modern approaches to file system integrity checking
PublicationOne of the means to detect intruder's activity is totrace all unauthorized changes in a file system.Programs which fulfill this functionality are called fileintegrity checkers. This paper concerns modernapproach to file system integrity checking. It reviewsarchitecture of popular systems that are widely used inproduction environment as well as scientific projects,which not only detect intruders but also take actions tostop their...
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Studies on the influence of β-cyclodextrin derivatives on the physical stability of famotidine
PublicationThe usage of Fourier transform infrared spectroscopy, near infrared spectroscopy, differential scanning calorimetry and microscopy is presented in this work focused on the exploration of the effect of CD on the physical stability of famotidine (FAM). The most significant information was achieved by analysis of the second derivatives ofnear infrared (NIR) spectra recorded. Changes in the shape of spectra derivatives allow...
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Problematyka dotycząca zapewnienia fotostabilności substancji leczniczych w postaciach leku
PublicationUV and visible radiation may influence on the stability of some active pharmaceutical ingredients and in a consequence destabilizes such medicinal products, causes changesin its physicochemical properties also with negative pharmacological and sometimes even toxic effects. For this reason it is important to conduct the routine testing photostability. The knowledge of chemistry and technology as well as some methods of...
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Detection of some volatile degradation products released during photoexposition of ranitidine in a solid state
PublicationRanitidine (RAN) is on top of the list of prescribed drugs, due to its popularity as a selective H2-receptor antagonist, which efficiently decreases the amount of acid produced in the stomach. RAN is not stable both in a solid state and in a solution, which creates manufacturing problems, requires appropriate storage conditions, and results in a short drug shelf-life. The aim of this work was to study the emission of volatile...
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Occurrence of Cyanobacteria in the Gulf of Gdańsk (2008–2009)
PublicationBlooms of cyanobacteria develop each summer in the Baltic Sea. Collecting complete data on this phenomenon is helpful in understanding the changes taking place in the Baltic Sea and forecasting the occurrence of these phenomena in the future. This dataset includes unpublished information about the occurrence of cyanobacteria in the Gulf of Gdańsk (Southern Baltic) in 2008 and 2009. The presented data combines basic physic-ochemical...
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Adaptive Method of Adjusting Flowgraph for Route Reconstruction in Video Surveillance Systems
PublicationPawlak’s flowgraph has been applied as a suitable data structure for description and anal- ysis of human behaviour in the area supervised with multicamera video surveillance system. Infor- mation contained in the flowgraph can be easily used to predict consecutive movements of a partic- ular object. Moreover, utilization of the flowgraph can support reconstructing object route from the past video images. However, such a flowgraph with...
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Effects of the polyhistidine tag on kinetics and other properties of trehalose synthase from Deionococcus geothermalis
PublicationTwo recombinant trehalose synthases from Deinococcus geothermalis (DSMZ 11300) were compared. A significant influence of the artificial polyhistidine tag was observed in protein constitution. The recombinant trehalose synthase from D. geothermalis with His6 -tag has a higher K m value of 254 mM, in comparison with the wild-type trehalose synthase (K m 170 mM), and displayed a lower activity of maltose conversion when compared...
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BLOOD PRESSURE ESTIMATION BY MEANS OF A JOINT IMPEDANCE– PHOTOPLETYSMOGRAPHIC METHOD
PublicationThe knowledge of patient’s day to day blood pressure changes is invaluable to physicians for both diagnostics and health monitoring reasons. Constant observation of the pressure throughout a day would provide even more valuable clinical information. A convenient non-invasive methods of blood pressure estimation for monitoring purposes are widely proposed. This work shows a statistical approach to...
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Scene Segmentation Basing on Color and Depth Images for Kinect Sensor
PublicationIn this paper we propose a method for segmenting single images from Kinect sensor by considering both color and depth information. The algorithm is based on a series of edge detection procedures designed for particular features of the scene objects. RGB and HSV color planes are separately analyzed in the first step with Canny edge detector, resulting in overall color edges mask. In depth images both clear boundaries and smooth...
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Evolutionary Sets of Safe Ship Trajectories: improving the method by adjusting evolutionary techniques and parameters
PublicationThe paper presents some of the evolutionary techniques used by the evolutionary sets of safe ship trajectories method. In general, this method utilizes a customized evolutionary algorithm to solve a constrained optimization problem. This problem is defined as finding a set of cooperating trajectories (here the set is an evolutionary individual) of all the ships involved in the encounter situation. The resulting trajectories are...