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Wyniki wyszukiwania dla: abyssal engineering
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High-speed fpga pipelined binary-to-residue converter
Publikacjaw pracy przedstawiono architekturę przepływowego konwertera z systemu z uzupełnieniem do 2 z systemu binarnego. zastosowano segmentację słowa wejściowego ze wstępną inwersją dla liczb ujemnych. reszty liczb reprezentowanych przez poszczególne segmenty są obliczane poprzez odczyt z pamięci adresowanej binarną reprezentacją segmentu. otrzymane reszty sumowane są w wielooperandowym sumatorze modulo z korekcją reszty dla liczb ujemnych.pracę...
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Determining heat transfer coefficients using evolutionary alogrithms
PublikacjaPokazano sposób kalibracji współczynnika wymiany ciepła za pomocą algorytmów ewolucyjnych. Wykorzystano tu minimalizację błędu między pomiarami a obliczeniami. Pokazano dwie metody optymalizacji: wielokryterialną i jednokryterialną.
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Non-linear FEM analysis of earthquake-induced pounding between the main building and the stairway tower of the Olive View Hospital
PublikacjaCelem artykułu jest dokładna, trójwymiarowa analiza MES dotycząca zderzeń pomiędzy budynkiem głównym a konstrukcją wolnostojącej klatki schodowej szpitala Olive View podczas trzęsienia ziemi San Fernando w roku 1971. Wyniki analizy pokazują, iż kolizje mogą prowadzić do znacznego wzrostu odpowiedzi lżejszej konstrukcji klatki schodowej, powodować uszkodzenia w miejscach kontaktu oraz potęgować uszkodzenia u podstawy tej budowli....
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Full scale measurements of pressure field induced on the quay wall by bow thrusters – indirect method for seabed velocities monitoring
PublikacjaThe paper presents the results of full-scale experimental investigation of loads generated on the quay wall by bow thrusters during unberthing of a self-manoeuvring vessel. The presented research allowed for the comparison of the measurements results with generally accepted empirical prediction methods and confirmed the utility of the developed measuring setup for the on-line monitoring of jet induced loads. The conclusions from the...
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Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker
PublikacjaThis paper aims to present a new approach in the prediction of manoeuvring abilities of pod-driven ships. A new mathematical model of motions based on MMG methodology was developed and a new type of description of forces acting on azimuth drives is presented. Captive model tests of medium-size coastal tanker and pod open water tests were carried out in CTO S.A. (Ship Design and Research Centre S.A.) to obtain hull hydrodynamic derivatives...
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Implementation of Haar wavelet, higher order Haar wavelet, and differential quadrature methods on buckling response of strain gradient nonlocal beam embedded in an elastic medium
PublikacjaThe present investigation is focused on the buckling behavior of strain gradient nonlocal beam embedded in Winkler elastic foundation. The first-order strain gradient model has been combined with the Euler–Bernoulli beam theory to formulate the proposed model using Hamilton’s principle. Three numerically efficient methods, namely Haar wavelet method (HWM), higher order Haar wavelet method (HOHWM), and differential quadrature method...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublikacjaThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Impact of high temperature drying process on beech wood containing tension wood
PublikacjaThe technology of high temperature drying has a great inuence on dimensional and selected physical changes in tension wood. Article is focused on the measurement properties such as moisture content, color changes and longitudinal warping. The quality of beech wood is determined based on structure and properties of wood, frequency of defects in wood material. The tension wood is considered as an important wood defect causing negative...
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Equivalent standard manoeuvres for pod-driven ships
PublikacjaProcedures for carrying out the manoeuvring tests presented in International Maritime Organisation (IMO) resolution MSC.137(76) are based on the capabilities of ships with conventional steering-propulsion systems. Therefore they do not correspond to ships with other steering-propulsion devices, like pod drives. IMO is aware of this shortcoming and for ships with non-conventional steering and propulsion system may permit the use...
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Expedited optimization of antenna input characteristics with adaptive Broyden updates
PublikacjaSimulation-driven adjustment of geometry and/or material parameters is a necessary step in the design of contemporary antenna structures. Due to their topological complexity, other means, such as supervised parameter sweeping, does not usually lead to satisfactory results. On the other hand, rigorous numerical optimization is computationally expensive due to a high cost of underlying full-wave electromagnetic (EM) analyses, otherwise...
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Fast multi-objective design optimization of microwave and antenna structures using data-driven surrogates and domain segmentation
PublikacjaPurpose Strategies and algorithms for expedited design optimization of microwave and antenna structures in multi-objective setup are investigated. Design/methodology/approach Formulation of the multi-objective design problem oriented towards execution of the population-based metaheuristic algorithm within the segmented search space is investigated. Described algorithmic framework exploit variable fidelity modeling, physics- and...
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Rapid multi-objective optimization of antennas using nested kriging surrogates and single-fidelity EM simulation models
PublikacjaEver increasing performance requirements make the design of contemporary antenna systems a complex and multi-stage process. One of the challenges, pertinent to the emerging application areas but also some of the recent trends (miniaturization, demands for multi-functionality, etc.), is the necessity of handling several performance figures such as impedance matching, gain, or axial ratio, often over multiple frequency bands. The...
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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublikacjaDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Observation Value Analysis – Integral Part of Bayesian Diagnostics
PublikacjaThe decision making process, in general, is understood as a process of selecting one of the available solutions to the problem. One of possible approaches supporting the process is Bayesian statistical decision theory providing a mathematical model to make decisions of a technical nature in conditions of uncertainty. Regarding above, a detailed subject of the research is to analyze the value of the observation, which is a part...
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Fast surrogate-assisted simulation-driven design of compact microwave hybrid couplers
PublikacjaThis work presents a robust methodology for expedited simulation-driven design optimization of compact microwave hybrid couplers. The technique relies on problem decomposition, and a bot-tom–up design strategy, starting from the level of basic building blocks of the coupler, and finishing with a tuning procedure that exploits a fast surrogate model of the entire structure. The latter is constructed by cascading local response surface...
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Experimental investigation of Steel–Concrete–Polymer composite barrier for the ship internal tank construction
PublikacjaTransportation of dangerous cargo by ships demands ensuring an appropriate protection level in case of an accident. Two of the most dangerous accident types resulting in an oil spill are grounding and ship to ship collision. The article presents results of research on a new composite construction for a ship hull that increases structural safety during collision. The concept of semi-elastic Steel–Concrete–Polymer structure is presented....
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Experimental study of the post tensioned prestressed concrete corbels
PublikacjaThe results of experimental investigation of 6 symmetrical double prestressed corbels of variable shear span to depth ratio and variable location of prestressing bars are presented in the paper. The post ten- sioned corbels were prestressed with Macalloy 1030 bars of 25 mm in diameter. The results of the tests were compared with the cracking and load carrying capacity of corbels reinforced with passive reinforce- ment. As a result...
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The influence of reinforcement on load carrying capacity and cracking of the reinforced concrete deep beam joint
PublikacjaThe paper presents the results of experimental research of the spatial reinforced concrete deep beam systems orthogonally reinforced and with additional inclined bars. Joint of the deep beams in this research was composed of the longitudinal deep beam with a cantilever suspended at the transversal deep beam. The cantilever deep beam was loaded throughout the depth and the transversal deep beam was loaded at the mid-span by longitudinal...
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Historical carpentry corner log joints—Numerical analysis within stochastic framework
PublikacjaThe paper presents the results of numerical analysis performed on historical, traditional carpentry corner logjoints of two basic topologies: the short-corner dovetail connection and the saddle notch connection. These types of carpentry joints are commonly used in currently preserved objects of wooden architecture. All connections have been modelled in pinewood, which has been defined in the Finite Element software MSC.Marc/Mentat...
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Polish experience in operation of sludge treatment reed beds
PublikacjaSludge Treatment Reed Beds (STRBs) is the technology of sludge treatment, which is based on natural processes occurring in the environment, in specially designed and operated facilities to achieve benefits for the environment. Integrated dewatering and stabilization occur in reed systems. For economic and environmental reasons it is an attractive solution, especially in rural areas where there are no appropriate facilities. In...
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The efficiency and reliability of pollutant removal in a hybrid constructed wetland with giant miscanthus and Jerusalem artichoke in Poland
PublikacjaIn this paper, we analysed the pollutant removal efficiency and reliability of a vertical and horizontal flow hybrid constructed wetland (CW) planted with giant miscanthus and Jerusalem artichoke. The wastewater treatment plant, located in south-eastern Poland, treated domestic sewage at an average flow rate of 1.2m3·d−1. The tests were carried out during. 5-years of operation of the sewage treatment plant (2011–2016). During this...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublikacjaData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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The selected roof covering technologies in the aspect of their life cycle costs
PublikacjaIn the article is presented an analysis of the life cycle costs calculation for selected roof coverings. The scope of research includes costs of construction, maintenance and demolition of the roof covering structure for two alternative technologies – the traditional and new generation. On the presented example of an industrial building with a roof area of 1000 m², the above costs are taken to consideration for the roof covering...
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Full-scale CFD simulations for the determination of ship resistance as a rational, alternative method to towing tank experiments
PublikacjaResults of ship resistance predictions obtained from towing tank experiments are affected by the method used to extrapolate from a model scale to a ship scale. Selection of method to determine a form factor is subjective and the extrapolation method is accurate for typical hull forms. For innovative hull forms the proper method for calculating the form factor is questionable. Moreover, the influence of the extrapolation method...
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A fast start-up of the organotrophic anammox process inoculated with constructed wetland sediment
PublikacjaOrganotrophic anaerobic ammonium oxidation (anammox) bacteria can utilize small volatile fatty acids with nitrate as electron acceptors with less energy consumption and no biomass production. To achieve a faster and stable start-up of organotrophic anammox process, in this study, the growth of organotrophic anammox bacteria seeded from hybrid constructed wetland (CW) sediment under different TOC/TN ratios and different chloramphenicol...
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25 years of research and experiences about the application of constructed wetlands in southeastern Poland
PublikacjaThis paper is a review of research and experiences related to the application of constructed wetland systems (CWs) in southeastern Poland in 1992–2016. On the basis of literature data, a comparison between pollutant removal efficiencies of one-stage and hybrid CWs was made. Some problems regarding the operation of these treatment plants were also presented. Data from various facilities indicate that one-stage CWs with horizontal...
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Reduced-cost surrogate modelling of compact microwave components by two-level kriging interpolation
PublikacjaFull-wave electromagnetic (EM) analysis is a versatile tool for evaluating the performance of high-frequency components. Its potential drawback is its high computational cost, inhibiting the execution of EM-driven tasks requiring massive simulations. The applicability of equivalent network models is limited owing to the topological complexity of compact microstrip components because of EM cross-coupling effects. Development of...
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Fast tolerance-aware design optimization of miniaturized microstrip couplers using variable-fidelity EM simulations and re-sponse features
PublikacjaManufacturing tolerances and other types of uncertainties may considerably affect operation and performance of microwave components and systems. Quantification of these effects is therefore an important part of the design process. It is even more important to obtain designs whose sensitivity to parameter deviations is reduced as much as possible. All of these require statistical analysis carried out at the level of electromagnetic...
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Geotechnical characterization of soft soil deposits in Northern Poland
PublikacjaThis 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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Patch size setup and performance/cost trade-offs in multi-objective EM-driven antenna optimization using sequential domain patching
PublikacjaPurpose This paper aims to assess control parameter setup and its effect on computational cost and performance of deterministic procedures for multi-objective design optimization of expensive simulation models of antenna structures. Design/methodology/approach A deterministic algorithm for cost-efficient multi-objective optimization of antenna structures has been assessed. The algorithm constructs a patch connecting extreme Pareto-optimal...
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Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size deter-mination
PublikacjaIn this paper, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement...
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On deterministic procedures for low-cost multi-objective design optimization of miniaturized impedance matching transformers
PublikacjaPurpose This paper aims to investigate deterministic strategies for low-cost multi-objective design optimization of compact microwave structures, specifically, impedance matching transformers. The considered methods involve surrogate modeling techniques and variable-fidelity electromagnetic (EM) simulations. In contrary to majority of conventional approaches, they do not rely on population-based metaheuristics, which permit lowering...
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Numerical assessment of ultimate strength of severe corroded stiffened plates
PublikacjaThe objective of this work is to investigate numerically (using the non-linear FEM and the approach stipulated by the Common Structural Rules) the severe nonuniform corrosion degradation effect on the ultimate strength of stiffened plates and compare the results to the already published experimental works. Different factors governing structural behavior of corroded stiffened plates are investigated, such as corrosion degradation level,...
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RANS-based design optimization of dual-rotor wind turbines
PublikacjaPurpose An improvement in the energy efficiency of wind turbines can be achieved using dual rotors. Because of complex flow physics, the design of dual-rotor wind turbines (DRWTs) requires repetitive evaluations of computationally expensive partial differential equation (PDE) simulation models. Approaches for solving design optimization of DRWTs constrained by PDE simulations are investigated. The purpose of this study is to determine...
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Adaptive dynamic control allocation for dynamic positioning of marine vessel based on backstepping method and sequential quadratic programming
PublikacjaIt is generally assumed in dynamic positioning of over-actuated marine vessels that the control effectiveness matrix (input matrix) is known and constant, or, in case of fault information, it is estimated by the fault detection and diagnosis system. The purpose of the study is to develop the adaptive dynamic positioning control system for an over-actuated marine vessel in the presence of uncertainties and with emphasis on limited...
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Investigations of the optical activity of nonlinear crystals by means of dual-wavelength polarimeter
PublikacjaA dual-wavelength method in high accuracy polarimetry has been successfully tested and applied to measure optical activity (OA) of nonlinear crystals. In proposed polarimetric scheme two neighboring semiconductor laser wavelengths (635 and 650 nm) are used, which increases number of parameters measured simultaneously and improves the data processing. By neglecting dispersion of eigen wave ellipticity in crystals, more efficient...
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Possibilities of Phoslock® application to remove phosphorus compounds from wastewater treated in hybrid wetlands
PublikacjaTreatment wetland technologies for wastewater treatment can be easily applied for removal of all pollutants except phosphorous. They are applicable in a small towns and rural areas, places where conventional wastewater treatment plant cannot properly operate because of common economic constraints. In Poland only the 8% of rural areas are equipped with sewer system, thus treatment wetlands might be an alternative, effective and...
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Variable-fidelity shape optimization of dual-rotor wind turbines
PublikacjaPurpose Dual-rotor wind turbines (DRWTs) are a novel type of wind turbines that can capture more power than their single-rotor counterparts. Because their surrounding flow fields are complex, evaluating a DRWT design requires accurate predictive simulations, which incur high computational costs. Currently, there does not exist a design optimization framework for DRWTs. Since the design optimization of DRWTs requires numerous model...
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Kinetics of pollutants removal in hybrid treatment wetlands – Case study comparison
PublikacjaRecent years have seen an increasing interest in hybrid constructed wetland (HCW) systems for domestic sewage treatment. This paper is focused on kinetics of removal of the main pollutants occurring in wastewater i.e. organics expressed as chemical oxygen demand, biochemical oxygen demand and total nitrogen. The purpose of the article is to compare different HCW configurations in terms of mass removal rates (MRR) and removal rate...
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Reliability of nitrogen removal processes in multistage treatment wetlands receiving high-strength wastewater
Publikacjareatment wetlands have been proved to be more effective than conventional treatment processes in case of high-strength wastewater containing high concentrations of ammonium nitrogen and recalcitrant organic matter. In this study nitrogen removal processes and reliability of nitrogen removal at two identical pilot-scale multistage treatment wetlands (MTWs) receiving real, non-synthetic wastewater were discussed. The wastewater discharged...
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The Review of the Selected Challenges for an Incorporation of Daylight Assessment Methods into Urban Planning in Poland
PublikacjaThe main objectives of this research it to find out if modern daylight assessment and design methods can be useful for urban residential planning in Poland. The study gives a chance to describe and appraise modern daylight design techniques. The other purpose is to illustrate how daylight knowledge could be used as an incentive to rethink the way urban environments are created. Although daylight design is acknowledged in literature...
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Landscape Rurality: New Challenge for The Sustainable Development of Rural Areas in Poland
PublikacjaThe standard of country living was a matter of Polish elites’ concern from the eighteenth century. In different historical conditions different concepts of the rural renewal were formed. Today in rural areas of Poland some spatial processes that threaten the quality of life occur. The disadvantageous changes are the result of national or local governments spatial policy and they are an inhabitants’ response to it. The political...
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A decision-making system supporting selection of commanded outputs for a ship's propulsion system with a controllable pitch propeller
PublikacjaThe ship's operators have to make decisions regarding the values of commanded outputs (commanded engine speed and pitch ratio) which ensure maximum vessel speed and minimum fuel consumption. Obviously, the presented decision problems are opposed. Therefore, there is a need for a compromise solution that enables more flexible vessel voyage planning. This paper deals with development of a computer-aided system supporting selection...
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The Use of the Language of Mathematics as an Inspiration for Contemporary Architectural Design
PublikacjaThe purpose of the article is to present the evolution of the use of mathematical language as an inspiration for creating spatial, three-dimensional forms in art and architecture. The article focuses on the possibilities for art and architectural design ideas gained by contemporary mathematics, algorithms and computational parametric approach. The analysis of various examples represents the relationships between the composition...
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Analysis of Historic Brick Walls' Strengthening Methods
PublikacjaAnalysis of the behavior of historical brick walls is difficult and complicated. However, computer calculations are being increasingly used in the evaluation of cultural heritage buildings and some of their elements. The aim of this paper is to analyze the historic brick walls reinforcement. Different methods of strengthening are compared and discussed. Numerical analysis, based on finite element method, was conducted on the assumption...
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Rapid design optimization of antennas using variable-fidelity EM models and adjoint sensitivities
PublikacjaPurpose – Development of techniques for expedited design optimization of complex and numerically expensive electromagnetic (EM) simulation models of antenna structures validated both numerically and experimentally. The paper aims to discuss these issues. Design/methodology/approach – The optimization task is performed using a technique that combines gradient search with adjoint sensitivities, trust region framework, as well as...
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Variable-fidelity CFD models and co-Kriging for expedited multi-objective aerodynamic design optimization
PublikacjaPurpose – Strategies for accelerated multi-objective optimization of aerodynamic surfaces are investigated, including the possibility of exploiting surrogate modeling techniques for computational fluid dynamic (CFD)-driven design speedup of such surfaces. The purpose of this paper is to reduce the overall optimization time. Design/methodology/approach – An algorithmic framework is described that is composed of: a search space reduction,...
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An analysis of domain-based ship collision risk parameters
PublikacjaAccording to a lot of contemporary research on ship collision avoidance the classic approach parameters – distance at closest point of approach (DCPA) and time to the closest point of approach (TCPA) – are not sufficient for estimating ship collision risk and for planning evasive manoeuvres. Consequently new measures are introduced, often utilizing the concept of a ship domain. Their drawback, up to this point, was the lack of...
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Participatory Budgeting in Poland – Missing Link in Urban Regeneration Process
PublikacjaIn last thirty years Poland has gone a long way toward democracy and decentralization. Role of public participation in planning is increasing rapidly and recently many new instruments of empowering the community is being introduced, participatory budgeting is one of the most important. On the other hand, urban regeneration is one of the most important challenges of polish cities are facing. Technical and transport infrastructure...
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A method of determining and visualizing safe motion parameters of a ship navigating in restricted waters
PublikacjaThe paper presents a method of displaying ship collision avoidance information which is based on an unconventional Collision Threat Parameters Area (CTPA) technique. The solution presented here extends CTPA's functionality from past works by supporting navigation in restricted waters and handling ship domains analytically instead of numerically. It visualizes potential navigational threats as well as possible collision avoidance...