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Geospatial Coverage and Signal Quality Measurements of Terrestrial DAB+ Network in Northern Poland
PublikacjaModern signal coverage maps are prepared based on industry-standard radio propagation models, which take into account a number of parameters, including: type of antenna, distance from the transmitter, type of terrain, etc. However, such simulations are prone to location-specific inaccuracies, and should be verified with in-situ measurements. This paper presents results of a field test of a terrestrial DAB+ (Digital Audio Broadcasting...
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Assessing unsignalised pedestrian crossings
PublikacjaThe lack of pedestrian safety on crossings is a complex problem and one that is influenced by a number of factors such as the law, road traffic culture, the road and traffic. This paper will focus on the last two by presenting a method for assessing pedestrian crossings for their geometry and roadside using data from 930 pedestrian crossings in Warsaw. The authors of this paper have attempted to systematise the process of assessment...
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Structure of solvation water around the active and inactive regions of a type III antifreeze protein and its mutants of lowered activity
PublikacjaWater molecules from the solvation shell of the ice-binding surface are considered important for the antifreeze proteins to perform their function properly. Herein, we discuss the problem whether the extent of changes of the mean properties of solvation water can be connected with the antifreeze activity of the protein. To this aim, the structure of solvation water of a type III antifreeze protein from Macrozoarces americanus (eel...
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Study on the Influence of an Axial Distance Between Rotors on a Performance of a Small Counter-Rotating Wind Turbine
PublikacjaIn this paper, results of the investigation on the performance of a small counter-rotating wind turbinehas been presented. Computational Fluid Dynamics methodshave been used forwind turbine simulations. Rotors representation were introduced into computational domain by means of Actuator Line Model. Influence of an axial distance of CRWTrotorshas been investigated. In all studied configurations rotors were counter-rotating...
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TeleCAD w kształceniu studentów Wydziału Inżynierii Lądowej Politechniki Gdańskiej
PublikacjaPrzedstawiono system TeleCAD opracowany w ramach projektu Leonardo da Vinci - Teleworkers Training for CAD Systems Users (1998-2001). Głównym celem projektu było stworzenie środowiska obsługi kursów programu AutoCAD bazującego na Internecie jako medium do komunikacji między uczestnikami oraz do dostarczania materiałów kursowych. W artykule zaprezentowano również system służący do oceny jakości szkoleń na odległość. Szkolenie TeleCAD...
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Investigations of Aerodynamics of Tesla Bladeless Microturbines
PublikacjaThe paper presents an analysis of a Tesla bladeless turbine for a co-generating micro-power plant of heat capacity 20 kW, whichoperates in an organic Rankine cycle with a low-boiling medium. Numerical calculations of flow in several Tesla turbine models areperformed for a range of design parameters. Results of investigations exhibit interesting features in the distribution of flowparameters within the turbine interdisk space. The...
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Recent Advances in Graphene Oxide-Based Membranes for Heavy Metal Ions Separation
PublikacjaGraphene oxide (GO)-based membranes have been widely investigated for separation of dyes, salt ions, heavy metal ions, and biomolecules due to their high mechanical strength, single-layered structure, large surface area, and high affinity. However, due to irregular pore structure, nanochannels, interlayer distance, easy functionalization, swelling effect, and chemical stability under aqueous environment limited their separation...
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Adaptive Method of Adjusting Flowgraph for Route Reconstruction in Video Surveillance Systems
PublikacjaPawlak’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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FINITE GROUND CPW-FED UWB ANTENNA OVER THE METALLIC CYLINDRICAL SURFACES
PublikacjaThe investigation of finite ground coplanar fed ultra-wideband (UWB) antenna and the influence of its curvature and the proximity of circular metallic screen on the reflection coefficients and radiation characteristics is presented. The antenna is composed of two circular coplanar strips which enclose slot aperture of similar shape and is designed on a thin and flexible substrate which allows its bending. The antenna configuration...
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Priority-enabled optimization of resource utilization in fault-tolerant optical transport networks.
PublikacjaW artykule zaproponowano nowe podejście do optymalizacji rozdziału zasobów przeżywalnych sieci rozległych, które uzależnia szybkość przywracania ciągłości połączenia od klasy usługi. Wykazano, iż proponowana metoda nie powoduje wydłużania ścieżek zabezpieczających (w przypadku usług w wymaganej wysokiej jakości obsługi) lub czyni to w sposób minimalny (dla pozostały usług). Ze względu na fakt, że zadanie znalezienia ścieżek aktywnych...
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The hydrodynamic pressure field of the ship Zodiak, measurements and calculations
PublikacjaThe article presents the results of measurements of the slowly changing hydrodynamic pressure field HPF generated by the movement of the ship, Zodiak, in the Bay of Gdansk. The measurement results have been obtained in the framework of the program of the work in Siramis, under the auspices of the European Defence Administration of the EU, by the research team of the Naval Academy in Gdynia. The measurement results were compared with...
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Fading Modelling in Dynamic Off-Body Channels
PublikacjaThis paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components,...
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Development and Research of the Text Messages Semantic Clustering Methodology
PublikacjaThe methodology of semantic clustering analysis of customer’s text-opinions collection is developed. The author's version of the mathematical models of formalization and practical realization of short textual messages semantic clustering procedure is proposed, based on the customer’s text-opinions collection Latent Semantic Analysis knowledge extracting method. An algorithm for semantic clustering of the text-opinions is developed,...
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On the partition dimension of trees
PublikacjaGiven an ordered partition Π={P1,P2,…,Pt} of the vertex set V of a connected graph G=(V,E), the partition representation of a vertex v∈V with respect to the partition Π is the vector r(v|Π)=(d(v,P1),d(v,P2),…,d(v,Pt)), where d(v,Pi) represents the distance between the vertex vv and the set Pi. A partition Π of V is a resolving partition of G if different vertices of G have different partition representations, i.e., for every...
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Assessment of image processing methods for the determination of propagation of squat-type defects in rails
PublikacjaWe demonstrate the idea of squat-type defect measurement in the rail and the concept of tracking of the defect development using the techniques of image acquisition and image processing as well as the methods of metric spaces. We introduce the concepts of a set diameter δ(A) and the metric ρ1, which come from the properties of plane figures, to compare and to observe the development of the defects. We characterize the feasibility...
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Method for Clustering of Brain Activity Data Derived from EEG Signals
PublikacjaA method for assessing separability of EEG signals associated with three classes of brain activity is proposed. The EEG signals are acquired from 23 subjects, gathered from a headset consisting of 14 electrodes. Data are processed by applying Discrete Wavelet Transform (DWT) for the signal analysis and an autoencoder neural network for the brain activity separation. Processing involves 74 wavelets from 3 DWT families: Coiflets,...
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Polynomial Algorithm for Minimal (1,2)-Dominating Set in Networks
PublikacjaDominating sets find application in a variety of networks. A subset of nodes D is a (1,2)-dominating set in a graph G=(V,E) if every node not in D is adjacent to a node in D and is also at most a distance of 2 to another node from D. In networks, (1,2)-dominating sets have a higher fault tolerance and provide a higher reliability of services in case of failure. However, finding such the smallest set is NP-hard. In this paper, we...
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Partition of friction heat between sliding semispaces due to adhesion-deformational heat generation
PublikacjaAnalytical expressions of heat-partition coefficient and contact temperatures for two sliding semispaces with account for adhesion-deformational heat generation and contact heat exchange have been obtained. The rate of deformational heat generation is assumed to decay exponentially with increase of distance from the interface. It has been shown that heat-generation configuration and the intensity of contact heat exchange have impact...
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Autonomous Control of the Underwater Remotely Operated Vehicle in Collision Situation with Stationary Obstacle
PublikacjaThe article considers the problem of autonomous control of the underwater remotely operated vehicle mini Remotely Operated Vehicle (ROV) in a collision situation with a stationary obstacle. The control of the collision avoidance process is presented as a synthesis of fuzzy proportional-differential controllers for the control of distance and orientation concerning the detected stationary obstacle. The control of the submergence...
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Dynamic Signal Strength Mapping and Analysis by Means of Mobile Geographic Information System
PublikacjaBluetooth beacons are becoming increasingly popular for various applications such as marketing or indoor navigation. However, designing a proper beacon installation requires knowledge of the possible sources of interference in the target environment. While theoretically beacon signal strength should decay linearly with log distance, on-site measurements usually reveal that noise from objects such as Wi-Fi networks operating in...
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Validation of Interpolation Algorithms for Multiscale UV-VIS Imaging Using UAV Spectrometer
PublikacjaIn this study, we present a comparison of popular methods for the interpolation of irregular spatial data in order to determine the applicability of each algorithm for hyperspectral reflectance estimation. The algorithms were benchmarked against a very high-resolution orthoimage from an RGB camera and medium-resolution satellite imagery from Sentinel-2A. We tested five interpolation algorithms: Triangulated Irregular Network (TIN),...
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Centrifuge modelling of tapered wall jacked into dense sand
PublikacjaA series of static penetration tests of trapezoidal walls in dense Fontainebleau sand were performed in the geotechnical centrifuge at Gustave Eiffel University. The models of wall with three different shapes (straight profile with thickness D=16mm, 0.75 degree and 1.5 degree of taper angle) but with the same volume were used. The soil mass was instrumented with five stress cells located at two levels at 2D, 4D and 6D distance...
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On-line Search in Two-Dimensional Environment
PublikacjaWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. As a way of modeling two-dimensional shapes, we restrict our attention to networks that are embedded into partial grids:...
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Stability of trusses with linear elastic side-supports
PublikacjaThe present research is devoted to study of a lateral buckling of truss with linear elastic side supports. The elastic support reaction in relation to force in compressed chord and coefficient of buckling length related to side support distance are also calculated. The effect of slope of side support on limit force is also considered. The nonlinear analysis of two roof trusses are carried out. The results are compared to design...
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Sounding of Layered Marine Bottom - Model Investigations
PublikacjaThe necessary actions connected with interpretations of examining of physical properties of sea bottom structure is developing of proper procedure of modeling of the layered structure. The implementation of the acoustic waves for the determination of seabed stratification requires a precise diagnosis of the topic from both the theoretical and practical side. Little differences between the parameters of sediments, as well as irregular...
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublikacjaSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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Camera Orientation-Independent Parking Events Detection
PublikacjaThe paper describes the method for detecting precise position and time of vehicles parking in a parking lot. This task is trivial in case of favorable camera orientation but gets much more complex when an angle between the camera viewing axis and the ground is small. The method utilizes background subtraction and object tracking algorithms for detecting moving objects in a video stream. Objects are classified into vehicles and...
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Capacity efficient shared protection and fast restoration scheme in self-configured optical networks
PublikacjaW artykule zaproponowano nową koncepcję optymalizacji rozdziału zasobów dla przeżywalnych sieci rozległych, która gwarantuje szybkie odtwarzanie usług po wystąpieniu awarii. Wykazano, iż proponowany algorytm, wykorzystujący ideę wierzchołkowego kolorowania grafów, nie powoduje wydłużania ścieżek zabezpieczających - zjawiska charakterystycznego dla powszechnie stosowanych algorytmów optymalizacji. Udowodniono, iż powyższa cecha...
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Experimental Study on Pounding between Structures during Damaging Earthquakes
PublikacjaMutual pounding between structures during earthquakes may cause serious structural damage. The aim of this paper is to show the results of a shaking table experimental study focused on pounding between structures in series under several earthquake excitations. The experiments were performed using three tower models with different configurations and different gap distances between them. In the first stage of the study, one rigid...
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PHONEME DISTORTION IN PUBLIC ADDRESS SYSTEMS
PublikacjaThe quality of voice messages in speech reinforcement and public address systems is often poor. The sound engineering projects of such systems take care of sound intensity and possible reverberation phenomena in public space without, however, considering the influence of acoustic interference related to the number and distribution of loudspeakers. This paper presents the results of measurements and numerical simulations of the...
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The Quick Measure of a Nurbs Surface Curvature for Accurate Triangular Meshing
PublikacjaNURBS surfaces are the most widely used surfaces for three-dimensional models in CAD/CAE programs. As a model for FEM calculation is prepared with a CAD program it is inevitable to mesh it finally. There are many algorithms for meshing planar regions. Some of them may be used for meshing surfaces but it is necessary to take the curvature of the surface under consideration to avoid poor quality mesh. The mesh must be denser in the...
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Crystal structure and electronic structure of CePt2In7
PublikacjaWe report a corrected crystal structure for the CePt2In7 superconductor, refined from single crystal x-ray diffraction data. The corrected crystal structure shows a different Pt–In stacking along the c-direction in this layered material than was previously reported. In addition, all of the atomic sites are fully occupied with no evidence of atom site mixing, resolving a discrepancy between the observed high resistivity ratio of...
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Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublikacjaThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
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Experimental study of the effect of vertical acceleration component on the slope stability
PublikacjaThe paper deals with the stability of earth dams subjected to seismic and paraseismic excitations occurring in the close distance to the dam. The Newmark’s stability approach, classified as a simplified dynamic method, has been extended for two directional dynamic loading case and the evolution of the friction coefficient. The paper is focused on the experimental verification of the proposed method for harmonic and cyclic excitations...
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Determination of equivalent axle load factors with the use of strain energy of distortion
PublikacjaThe paper proposes a new method for calculation of equivalent axle load factors based on the analysis of strain energy of distortion induced in road pavements by traffic loads. The main advantage of the method is the more accurate calculation of the effects of multiple axles and super single versus dual tyres. The methodconsiders the location of critical points, at which strain energy of distortion reaches extreme values. When...
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User Mobility’s Influence on System Loss in Off-Body BAN Scenarios
PublikacjaIn this paper, a measurement campaign for off-body communications in an indoor environment is investigated for a set of on-body antennas. The channel impulse response was measured with the user approaching and departing from an off-body fixed antenna using two user dynamics: standing at fixed positions and walking. The processing of the measurement data allowed to evaluate system loss statistics. Different antenna configurations...
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Mobility’s Influence on System Loss in Off-Body BAN Scenarios
PublikacjaIn this paper, a measurement campaign for off body communications in an indoor environment is investigated for a set of on-body antennas. The channel impulse response was measured with the user approaching and departing from an off-body fixed antenna using two user dynamics, standing at fixed positions and walking. The processing of the measurement data allowed to evaluate system loss statistics. Different antenna configurations...
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Structure and transport properties of donor-doped barium strontium cobaltites
PublikacjaIn this work, Nb-substituted barium strontium cobaltites Ba0.5Sr0.5Co1-xNbxO3-δ (x = 0 – 0.4) have been fabricated and studied. The structural analysis showed that the Nb content influences the lattice constant as well as the distance between the (Co, Nb) and oxygen atoms. The study of morphology of samples showed that the Nb content does not change the porosity, grain size and morphology of the ceramics. The total electrical conductivity...
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Performance Evaluation of GAM in Off-Body Path Loss Modelling for Body Area Networks
PublikacjaThis paper addresses the performance evaluation of an off-body path loss model, based on measurements at 2.45 GHz, which has been developed with the use of the Generalised Additive Model, allowing to model a non-linear dependence on different predictor variables. The model formulates path loss as a function of distance, antennas’ heights, antenna orientation angle and polarisation, results showing that performance is very sensitive...
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Automatic Clustering of EEG-Based Data Associated with Brain Activity
PublikacjaThe aim of this paper is to present a system for automatic assigning electroencephalographic (EEG) signals to appropriate classes associated with brain activity. The EEG signals are acquired from a headset consisting of 14 electrodes placed on skull. Data gathered are first processed by the Independent Component Analysis algorithm to obtain estimates of signals generated by primary sources reflecting the activity of the brain....
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CNN Architectures for Human Pose Estimation from a Very Low Resolution Depth Image
PublikacjaThe paper is dedicated to proposing and evaluating a number of convolutional neural network architectures for calculating a multiple regression on 3D coordinates of human body joints tracked in a single low resolution depth image. The main challenge was to obtain a high precision in case of a noisy and coarse scan of the body, as observed by a depth sensor from a large distance. The regression network was expected to reason about...
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A spatio-temporal approach to intersectoral labour and wage mobility
PublikacjaThe article presents the spatio-temporal approach for intersectoral labor and wage mobility. Analyses of interindustry mobility were performed with the use of general entropy mobility indices (GEMM). Spatio- temporal approach was obtained thanks to the separate measurement of spatial autocorrelation and regression for each set of sectoral wage and employment structure and was conducted in each year of the research period separately....
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Comparing the Effectiveness of ANNs and SVMs in Forecasting the Impact of Traffic-Induced Vibrations on Building
PublikacjaTraffic - induced vibrations may cause damage to structural elements and may even lead to structural collapse. The aim of the article is to compare the effectiveness of algorithms in forecasting the impact of vibrations on buildings using the Machine Learning (ML) methods. The paper presents two alternative approaches by using Artificial Neural Networks (ANNs) and Support Vector Machines (SVMs). Factors that may affect traffic-induced...
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A Spatio-temporal Approach to Intersectoral Labour and Wage Mobility
PublikacjaThe article presents the spatio-temporal approach for intersectoral labor and wage mobility. Analyses of interindustry mobility were performed with the use of general entropy mobility indices (GEMM). Spatio-temporal approach was obtained thanks to the separate measurement of spatial autocorrelation and regression for each set of sectoral wage and employment structure and was conducted in each year of the research period separately....
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Is This Distance Teaching Planning That Bad?
PublikacjaIn spring 2020, university courses were moved into the virtual space due to the Covid-19 lockdown. In this paper, we use experience from courses at Gdańsk University of Technology and ETH Zurich to identify core problems in distance teaching planning and to discuss what to do and what not to do in teaching planning after the pandemic. We conclude that we will not return to the state of (teaching) affairs that we had previously....
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Modelling of residential sales price with kriging using different distance metrics in different correlation functions
PublikacjaThe modelling and estimation of sales prices based on economical conditions are important for housing sector especially in developing countries. Analysts are focused on the subject to analyze price movements and estimate the future trend of the sales prices for housing sector. In this study, we tried to generate a robust and efficient model related to the subject. Firstly, we investigated economic variables affecting housing sales...
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Some aspects of noise generated by a small ship in the shallow sea
PublikacjaThe passing and underwater moving objects produce the noises of variable intensity, which significantly increase the overall level of noise in the sea. This applies to both the sonic and ultrasonic range. The excessive levels of underwater noise adversely affects the so-called underwater acoustic climate and is the reason why this phenomenon is intensively investigated from the number of years. The results of experimental work...
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Steering is an essential feature of non-locality in quantum theory
PublikacjaA physical theory is called non-local when observers can produce instantaneous effects over distant systems. Non-local theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in a well-known class of non-local games known as XOR games. In particular, optimal quantum strategies for XOR games are completely determined...
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Smart Services supporting Drivers in Effective Cars Parking
PublikacjaThe paper shows how to design and implement intelligent, service oriented systems for management of free places in distributed car parks. The idea of SOA technology is widely used. It is assumed that a state of every car park is automatically determined by a special electronic infrastructure including IoT solutions. The information received from such an infrastructure is sent to the main management system, which processes it and,...
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Electronic structure and rovibrational predissociation of the 2^1Π state in KLi
PublikacjaAdiabatic potential energy curves of the 3^1Σ^+, 3^3Σ^+, 2^1Π and 2^3Π states correlating for large internuclear distance with the K(4s) + Li(2p) atomic asymptote were calculated. Very good agreement between the calculated and the experimental curve of the 2^1Π state allowed for a reliable description of the dissociation process through a small (∼20 cm−1 for J = 0) potential energy barrier. The barrier supports several rovibrational...