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Search results for: AVOIDING COLLISIONS
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Positron Scattering and Annihilation in Organic Molecules
PublicationIn this paper, we address the problem of connecting positron lifetimes in liquids with collision cross sections in gases. We present the analyses of annihilation lifetime spectra of positrons in the liquid benzene, c-hexane, n-hexane, methanol and ethanol and calculations of scattering cross sections of positrons with benzene and c-hexane in the gas phase.
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Simultaneous optical and electrochemical label-free biosensing with ITO-coated lossy-mode resonance sensor
PublicationIn this work we discuss a new label-free biosensing device based on indium tin oxide (ITO) overlaid section of a multimode optical fiber fused silica core. The sensor has been used to optical measurements also simultaneously interrogated electrochemically (EC). Due to optimized thickness and optical properties of ITO film, a lossy-mode resonance (LMR) could be observed in the optical domain, where electrical properties of the film...
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Homoclinics for singular strong force Lagrangian systems in R^N
PublicationWe will be concerned with the existence of homoclinics for second order Hamiltonian systems in R^N (N>2) given by Hamiltonians of the form H(t,q,p)=Φ(p)+V(t,q), where Φ is a G-function in the sense of Trudinger, V is C^2-smooth, periodic in the time variable, has a single well of infinite depth at a point ξ and a unique strict global maximum 0 at the origin. Under a strong force type condition aroud the singular point ξ, we prove...
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The idea of a robotic single-sided lapping system
PublicationThis paper reviews the idea of a robotic lapping system. Robot’s assistance automates the lap-ping process and supports the development of a flexible lapping system. However, the main aim behind the idea of a robotic lapping system is to provide improved means for controlling the posi-tion of conditioning rings on a lapping plate. Due to the kinematics of lapping process, the profile wear of the tool is not constant along the radius....
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Bridging the gap between architectural and environmental engineering education in the context of climate change
PublicationIndicated in this article is the urgent need to adjust architectural education to the challenges triggered by climate change. Although reports on the future scenarios for cities are alarming, documents that set criteria for architectural education do not indicate competencies related to climate change adaptation and mitigation, mainly by avoiding environmental engineering considerations. An immediate answer to this problem could...
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Optimum shapes and dimensions of rubber bumpers in order to reduce structural pounding during seismic excitations
PublicationLarge displacement of structures observed during seismic excitations may lead to collisions between two adjacent, insufficiently-separated buildings and may result in major damages of both of them. In many building codes, appropriate equations or approximately recommended distances between structures in order to avoid pounding hazard have been introduced. Unfortunately, further, more detailed considerations show that safety situation...
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Technical and Economic Analysis of the Implementation of Selected Variants of Road Investment
PublicationThe aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to indicate an effective solution that, taking into account technical modifications of the road system elements, will ensure the functionality of the road system to the highest...
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Detection of person presence and its activity in the bathtub
PublicationA practical application of a bioimpedance technique for a detection of a bathing person is presented in the paper. It addresses the possibility of supervising people in the bathtub without voiding of their intimacy. The measurement system installed in a fiber-glass or a plastic bathtub is able to detect a presence of the bathing person, to estimate its activity and thus to detect potentially dangerous events. In the paper a principle...
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On the influence of shell element properties on the response of car model in crash test
PublicationIt goes without saying that numerical simulations play important role in the modern engineering practice. Contemporary CAD environments combined with FEM solvers, along with computer power of modern processors, give the engineer fast and efficient tool. Ultimately, however it is the user alone who is responsible for the correctness of the results. As long as the FEM calculations remain in the sphere of academic exercise, the inevitable...
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Improvement of Fingerprinting Method based on Hill Cipher by using Frequency Domain
PublicationThe main goal of this paper is to present the advantages of a digital fingerprinting in a frequency domain over a pixel domain, in case of VoD services (Video on Demand). The paper presents basic issues of a multimedia data protection by digital fingerprinting. It also describes threats to embedded fingerprints from both collusion attacks and from a transmission itself. Possible solution was presented on the example of the DCT...
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From flow to jamming: Lattice Gas Automaton simulations in granular materials
PublicationWe introduce the first extension of a Lattice Gas Automaton (LGA) model to accurately replicate observed emergent phenomena in granular materials with a special focus on previously unexplored jamming transitions by incorporating gravitational effects, energy dissipation in particle collisions, and wall friction. We successfully reproduce flow rate evolution, density wave formation, and jamming transition observed in experiments....
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Polyurethanes
PublicationHandbook of Thermoset Plastics, Fourth Edition provides complete coverage of the chemical processes, manufacturing techniques and design properties of each polymer, along with its applications. This new edition has been expanded to include the latest developments in the field, with new chapters on radiation curing, biological adhesives, vitrimers, and 3D printing. This detailed handbook considers the practical implications of using...
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The Boltzmann sequence-structure channel
PublicationWe rigorously study a channel that maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein statistics. This channel, which we also call the Boltzmann sequence-structure channel, is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. In our previous work, we verified experimentally that the channel capacity has a phase transition for...
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Polarisation effects in low-energy positron–molecule scattering
PublicationThe UK molecular R-matrix method has been adapted to treat positron collisions from polyatomic targets. A simple empirical enhancement factor which corrects for the underestimation of electron–positron polarisation and correlation effects in the calculations performed with the static-plus-polarization model at low scattering energies is presented. Application of this model to positron scattering from carbon dioxide at energies...
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Determination of Peak Impact Force for Buildings Exposed to Structural Pounding during Earthquakes
PublicationStructural pounding between adjacent, insufficiently separated buildings, or bridge segments, has been repeatedly observed during seismic excitations. Such earthquake-induced collisions may cause severe structural damage or even lead to the collapse of colliding structures. The aim of the present paper was to show the results of the study focused on determination of peak impact forces during collisions between buildings exposed...
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ADOPTED ISOCHRONE METHOD IMPROVING SHIP SAFETY IN WEATHER ROUTING WITH EVOLUTIONARY APPROACH
PublicationThe paper is focused on adaptation of an isochrone method necessary for application to a weather routing system with evolutionary approach. Authors propose an adaptation of the isochrone method with area partitioning assuring that the route found by the adopted method would not cross land. In result, when applied to a weather routing system with evolutionary approach, this proposal facilitates creation of initial population, resulting...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublicationWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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Perspectives on the replacement of harmful organic solvents in analytical methodologies: a framework toward the implementation of a generation of eco-friendly alternatives
PublicationVolatile organic solvents derived from non-renewable fossil feedstocks are commonplace in analytical laboratories. In spite of their convenient performance in countless unit operations, their environmental, health and safety issues represent a major area of concern. The progressive replacement of organic solvents obtained from fossil resources by eco-friendly alternatives would involve remarkable advances within the framework of...
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On some Zarankiewicz numbers and bipartite Ramsey Numbers for Quadrilateral
PublicationThe Zarankiewicz number z ( m, n ; s, t ) is the maximum number of edges in a subgraph of K m,n that does not contain K s,t as a subgraph. The bipartite Ramsey number b ( n 1 , · · · , n k ) is the least positive integer b such that any coloring of the edges of K b,b with k colors will result in a monochromatic copy of K n i ,n i in the i -th color, for some i , 1 ≤ i ≤ k . If n i = m for all i , then we denote this number by b k ( m )....
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A solid phase extraction–ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples
PublicationA new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE – for sample preparation) coupled with ion chromatography–conductivity detection (IC-CD – for the final determination). Mean recoveries of...
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Wczesny Mickiewicz jako zapowiadający się historiozof
PublicationThe paper shows young Mickiewicz’s family and historical experiences. It discussesthe knightly premises for his historiosophy and explains its radicalism and structureon the grounds of the knightly tradition. The study reveals the pre-Slavic deposits ofspiritual archeology in the Romantic poet. It proves that the activation of these depositsshaped Mickiewicz’s view on the collision between Poland and...
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On the validation of the LS-DYNA Geo Metro numerical model
PublicationThe paper presents experiences gained during work with numerical model of Geo Metro vehicle used for simulations of crash tests with road safety barriers. Attention is drawn to the subject of tire/wheel breakage during collision events. Some methods for improvement of the model are presented in the paper. Several results for the normative vehicle numerical tests are introduced. Simulations were carried out using LS-DYNA finite...
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H2O˙+ and OH+ reactivity versus furan: experimental low energy absolute cross sections for modeling radiation damage
PublicationRadiotherapy is one of the most widespread and efficient strategies to fight malignant tumors. Despite its broad application, the mechanisms of radiation-DNA interaction are still under investigation. Theoretical models to predict the effects of a particular delivered dose are still in their infancy due to the difficulty of simulating a real cell environment, as well as the inclusion of a large variety of secondary processes. This...
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Optimizing the computation of a parallel 3D finite difference algorithm for graphics processing units
PublicationThis paper explores the possibilities of using a graphics processing unit for complex 3D finite difference computation via MUSTA‐FORCE and WENO algorithms. We propose a novel algorithm based on the new properties of CUDA surface memory optimized for 2D spatial locality and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. A case study was performed for...
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Seismic Pounding Between Bridge Segments: A State-of-the-Art Review
PublicationEarthquake-induced structural pounding in bridge structures has been observed in several previous seismic events. Collisions occur at the expansion joints provided between adjacent decks or between the deck and abutment. Pounding between the structural elements may lead to severe damages and even to the unseating of the bridge in certain cases. Several investigations have been performed to study pounding in bridges under uniform...
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Study on polymer elements for mitigation of earthquake-induced pounding between buildings in complex arrangements
PublicationPounding between neighbouring buildings during earthquakes has been identified as one of the reasons for substantial damage or even total collapse of colliding structures, so it has been the subject of numerous studies in the recent years. A major reason leading to interactions between adjacent, insufficiently separated structures results from the differences in their dynamic properties. The problem is much more complicated for...
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Neural Networks, Support Vector Machine and Genetic Algorithms for Autonomous Underwater Robot Support
PublicationIn this paper, artificial neural networks, a classification technique called support vector machine and meta-heuristics genetic algorithm have been considered for development in autonomous underwater robots. Artificial neural networks have been used for seabed modelling as well as support vector machine has been applied for the obstacles classification to avoid some collision problems. Moreover, genetic algorithm has been applied...
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Electron Scattering on X(CH3)4 Molecules: Applicability of Simple Additivity Rule and Role of Methylation
PublicationTo investigate influence of target methylation (substitution of a hydrogen atom by methyl group) on electron-collision processes we compare absolute total cross sections for XH4 and X(CH3)4 molecules, where X is Si and Ge, respectively. We also compare experimental TCSs energy dependencies with estimated data obtained using simple formula and TCSs for methyl group and those for SiH4 and GeH4. Electron-scattering TCSs for mentioned...
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Distributed Evolutionary Algorithm for Path Planning in Navigation Situation
PublicationThis article presents the use of a multi-population distributed evolutionary algorithm for path planning in navigation situation. The algorithm used is with partially exchanged population and migration between independently evolving populations. In this paper a comparison between a multi-population and a classic single-population algorithm takes place. The impact on the ultimate solution has been researched. It was shown that using...
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Examining Impact of Speed Recommendation Algorithm Operating in Autonomous Road Signs on Minimum Distance between Vehicles
PublicationAn approach to a new kind of recommendation system design that suggests safe speed on the road is presented. Real data obtained on roads were used for the simulations. As part of a project related to autonomous road sign development, a number of measurements were carried out on both local roads and expressways. A speed recommendation model was created based on gathered traffic data employing the traffic simulator. Depending on...
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Cross section calculations for electron scattering from platinum chemotherapeutic compounds
PublicationCross section for electron impact ionization of carboplatin, C6H12N2O4Pt, and oxaliplatin, C8H14N2O4Pt, have been calculated within binary-encounter-Bethe model for energies from the ionization threshold up to 5000 eV. Cross section for elastic electron scattering from carboplatin and oxaliplatin molecules have also been derived using independent atom method (IAM) and additivity rule for collision energies ranging from 50 eV to...
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On the influence of the acceleration recording time on the calculation of impact severity indexes
PublicationThe paper concerns with the analysis of normative requirements pertaining to experimental setup of a crash test and its numerical modelling. An overview of parameters describing the collision of a vehicle with a road restraining system is presented. A short description of a concrete road safety barrier is presented. A brief description of numerical modelling procedures for crash tests is given as well. The parametric influence...
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Verification of Formulas for Periods of Adjacent Buildings Used to Assess Minimum Separation Gap Preventing Structural Pounding during Earthquakes
PublicationInsufficient separation distance between adjacent buildings may lead to serious damages during earthquakes due to structural pounding. The best way to prevent collisions is to provide sufficiently large separation distance between the structures. In this paper, the periods of two closely-spaced linear and nonlinear buildings have been investigated so as to accurately assess the minimum in-between separation gap. A new equation...
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Numerical Study of the Impinging Jets Formed by an Injector with Different Nozzle Diameters
PublicationThe collision of two or more liquid jets may provide considerable atomisation and efficient mixing of injected substances at the same time. This phenomenon is used, among others, in rocket engines, where the fuel and oxidiser are introduced separately and almost immediately mixed through self-impingement. Depending on the injection and operating conditions, diverse configurations of impinging jets are used, such as doublets,...
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REVIEW OF WEATHER FORECAST SERVICES FOR SHIP ROUTING PURPOSES
PublicationWeather data is nowadays used in a variety of navigational and ocean engineering research problems: from the obvious ones like voyage planning and routing of sea-going vessels, through the analysis of stability-related phenomena, to detailed modelling of ships’ manoeuvrability for collision avoidance purposes. Apart from that, weather forecasts are essential for passenger cruises and fishing vessels that want to avoid the risk...
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Electron-scattering cross sections for selected alkyne molecules: Measurements and calculations
PublicationWe report cross-section results from experimental and theoretical studies on electron collisions with 1-butyne (HC≡C–CH2CH3) and acetylene (HC≡CH) molecules and from computations for a propyne (HC≡C–CH3) molecule. Absolute grand -total electron-scattering cross sections (TCSs) were measured at impact energies ranging from about 0.5 to 300 eV using the linear electron-transmission method. The TCS energy curve for 1-butyne has a...
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Influence of separation gap on the structural response of colliding structures under earthquake excitation
PublicationThe high level of urbanization in the XXIst century forces the designers to design closely-separated structures and to take into account many factors influencing their response during seismic excitation, which are the most unpredictable loads which can affect civil engineering structures. Interactions between insufficiently adjacent buildings, known as the earthquake-induced structural pounding, may cause serious damage to the structures,...
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Seismic gap between buildings founded on different soil types experiencing pounding during earthquakes
PublicationSeveral formulas have been suggested in the literature to evaluate the minimum seismic gap that would prevent collisions between adjacent buildings during earthquakes, including those based on the absolute sum of the peak displacements (ABS), square root of the sum of the squares (SRSS), the double difference method (DDC), Australian code, and approach proposed by Naderpour et al. The aim of the present study is to evaluate the...
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Study on Polymer Elements for Mitigation of Earthquake-Induced Pounding Between Buildings in Complex Arrangements
PublicationPounding between neighboring structures during seismic events has been revealed as one of the most commonly observed reasons for severe damage or even total collapse of the adjacent buildings. Therefore, pounding effects have recently become an issue of great interest of many numerical and experimental investigations in many earthquake-prone regions of the world. It has also been observed that the differences in dynamic characteristics...
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Effects of Deck-Abutment Pounding on the Seismic Fragility Curves of Box-Girder Highway Bridges
PublicationEarthquake-induced pounding in bridges is a complex contact phenomenon in which the dynamic responses of structures, including collisions between deck and abutments, are strongly related to structural properties and earthquake excitation. The goal of this study is to develop and compare the seismic fragility curves of overall system and individual components of regular and irregular box-girder highway bridges in two cases: with...
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The role of time perspectives and impulsivity dimensions in coping styles
PublicationBoth time perspectives and impulsivity dimensions are groups of traits that are connected to self-control abilities and might be important for coping styles. However, to date, no study has systematically investigated their utility in predicting coping styles with regard to their multidimensional nature. The current study was correlational and exploratory, aiming to discover what amount of variance in each of the three coping...
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Koncepcja systemu wspomagania decyzji nawigatora statku opartego na ewolucyjnym planowaniu manewrów antykolizyjnych
PublicationArtykuł przedstawia koncepcję systemu wspomagania decyzji nawigatora statku opartego na wątkach badań prowadzonych wcześniej przez autora. System będzie rozszerzał funkcjonalność systemów dotychczasowych o możliwość szczegółowego planowania bezpiecznej trajektorii statku na wodach zamkniętych, z dużą liczbą statków obcych i ograniczeniami toru wodnego. Artykuł zawiera dyskusję możliwych podejść do planowania manewrów, optymalizacji...
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Water-Lubricated Journal Bearings Marine Applications, Design, and Operational Problems and Solutions
PublicationWater-Lubricated Journal Bearings: Marine Applications, Design, and Operational Problems and Solutions provides cutting-edge design solutions, common problems and methods for avoiding them, and material selection considerations for the use of water-lubricated journal bearings in marine environments. These bearings have many advantages, including the absence of the potential for oil contamination. They are also sensitive, and their...
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Cops, a fast robber and defensive domination on interval graphs
PublicationThe game of Cops and ∞-fast Robber is played by two players, one controlling c cops, the other one robber. The players alternate in turns: all the cops move at once to distance at most one each, the robber moves along any cop-free path. Cops win by sharing a vertex with the robber, the robber by avoiding capture indefinitely. The game was proposed with bounded robber speed by Fomin et al. in “Pursuing a fast robber on a graph”,...
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Impact of Initial Population on Evolutionary Path Planning Algorithm
PublicationIn this paper an impact of initial population on evolutionary path planning algorithm is presented. Tested algorithm is used to determine close to optimal shippaths in collision avoidance situation. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. For the simulation purposes a close to real tested environment is created. Four tests are performed....
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Formation of OH Radicals as Evidence of Intramolecular Hydrogen Migration in Cation-Induced Dissociation of Furan Molecules
PublicationWe present the experimental results on a hydrogen atom migration preceding fragmentation of the furan molecules induced by the H3+ and C+ impact. The excited OH(A2Σ+) radical has been detected among the furan decomposition products using collision-induced emission spectroscopy. However, the OH moiety is absent in the furan ring skeleton, so detecting the OH(A2Σ+→X2Π) luminescence indicates the intramolecular H atom relocation prior...
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Finite element method simulations of various cases of crash tests with N2/W4/A steel road barrier
PublicationThe subject of this study is performance of N2/W4/A steel road safety barrier investigated in numerical simulations. System was checked under several types of initial conditions, which were assumed basing on the TB11 and TB32 normative crash tests. The main goal of present study is to investigate the relationship between initial conditions (angle and velocity) of the impact and the severity indices (associated to the vehicle occupant) during...
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The Niching Mechanism in the Evolutionary Method of Path Planning
PublicationThis paper presents the concept of the niching mechanism in the evolutionary method of path planning. The problem is considered based on the example of a ship path planning. In this method the diversity of individuals is tested in respect to their physical distance, not the fitness function value. The researches show that such an approach increases effectiveness of solution space exploration, what results in a final solution with...
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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...
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Safety Assessment of Tram Stops
PublicationThe safety of public transport stops is the subject of numerous studies in large agglomerations around the world. This is due to the fact that it is a passenger exchange zone where collisions and accidents involving people getting on or off public transport vehicles most often occur. For this reason, the purpose of the article is to present the results of the safety assessment of the stop zones for two selected tram lines in Wroclaw....