Filters
total: 1779
filtered: 1673
displaying 1000 best results Help
Search results for: RISK-BASED SHIP DESIGN
-
Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction
PublicationPrediction of the maneuvering characteristics of the ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as direct simulation of the standard maneuvers with the free running model, which gives the most accurate results, but is also the least affordable as it requires very large tank or natural lake, as well as complex equipment of the...
-
Simplified approach to assess the dynamic response of a container ship subjected to bow slamming load
PublicationSimplified approach to assess the dynamic response of a container ship subjected to the bow slamming load, resulting in a transient vibratory response, typically called a 'whip-ping', is presented. The accurate numerical modelling is very complex and involves cou-pling of the hydrodynamic and structural solution at every time step, leading to huge com-putational and workload cost. Thus, the one-way coupling methodology is adopted,...
-
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...
-
Fast multi-objective design optimization of microwave and antenna structures using data-driven surrogates and domain segmentation
PublicationPurpose 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...
-
Ryzyko realizacji prac projektowych i prowadzenia przebudowy obiektów prywatnych
PublicationW artykule przedstawiono przykład realizacji przebudowy prywatnego budynku mieszkalnego, podczas której okazało się, że nie jest on wykonany zgodnie z projektem i zasadami sztuki budowlanej. Opracowany i zatwierdzony projekt budowlany przebudowy niewiele miał wspólnego z obiektem, którego dotyczył. Realizacja prac zgodnie z tym projektem była więc obarczona dużym ryzykiem, a w konsekwencji groziła katastrofą budowlaną.
-
Low-Cost Automated Design of Compact Branch-Line Couplers
PublicationBranch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important prerequisite for their application in modern devices. State-of-the-art approaches to design of compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line...
-
Modelling, Simulation and Optimization of the Wavemaker in a Towing Tank
PublicationThe paper analyses the problem of experimental identification (frequency response), modelling and optimization of the towing tank wavemaker in the Scilab/Xcos environment. The experimental identification of the objects (the towing tank wavemaker placed in the hydrodynamic laboratory of the CTO S.A. Ship Design and Research Centre (CTO)) and the implementation of the models in the simulation environment, enable to perform: 1. tuning...
-
An attempt to create a digital reconstruction of the Copper Ship = Próba cyfrowej rekonstrukcji kadłuba wraku Miedziowca
PublicationThis study presents an attempt to create a digital reconstruction of the W-5 shipwreck (the Copper Ship) based on data acquired by 3D scanning of structural components held at the National Maritime Museum in Gdańsk and on a physical reconstruction model of the ship’s hull. A digital reconstruction would facilitate analysis of various possible options for the structural design of the hull, and would enable the preparation of a model for...
-
EVALUATION OF EFFECTIVENESS OF WATERJET PROPULSOR FOR A SMALL UNDERWATER VEHICLE
PublicationT he goal of the project described is to replace the existing propulsion system of a small underwater vehicle with a solution less prone to mechanical damage and ensuring a lower risk of the entanglement of fibrous objects suspended in the body of water. Four typical marine screws are utilised in the current design of the vehicle. One possible solution of the problem is the application of waterjet propulsors located...
-
Electromagnetic Simulation with 3D FEM for Design Automation in 5G Era
PublicationElectromagnetic simulation and electronic design automation (EDA) play an important role in the design of 5G antennas and radio chips. The simulation challenges include electromagnetic effects and long simulation time and this paper focuses on simulation software based on finite-element method (FEM). The state-of-the-art EDA software using novel computational techniques based on FEM can not only accelerate numerical analysis, but...
-
Currently Commercially Available Chemical Sensors Employed for Detection of Volatile Organic Compounds in Outdoor and Indoor Air
PublicationThe paper presents principle of operation and design of the most popular chemical sensors for measurement of volatile organic compounds (VOCs) in outdoor and indoor air. It describes the sensors for evaluation of explosion risk including pellistors and IR-absorption sensors as well as the sensors for detection of toxic compounds such as electrochemical (amperometric), photoionization and semiconductor with solid electrolyte ones....
-
Analysis of magnetic field distribution inside ferromagnetic thin shells during degaussing process
PublicationAnalysis of the demagnetization of a large ferromagnetic object like a ship, was conducted. The approximate mathematical model in the form of a long cylindrical shell of constant magnetic permeability was applied. The discrete degaussing winding was assumed and the current density and magnetic flux density distribution in the ferromagnetic shell wall were determined. Based on the frequential and temporal analysis the recommended...
-
The problem of infections associated with implants – an overview
PublicationImplant-associated infections are serious and relatively common complication that leads to implant loss. The purpose of this paper is to gather knowledge about this issue. A literature review of the epidemiology, risk factors and pathogenesis of infections related to implants was carried out. This position collects data on commonly used implants and infections associated with them from various fields of medicine and contains classifications...
-
Towards evaluation of the Second Generation Intact Stability Criteria - examination of a fishing vessel vulnerability to surf-riding, based on historical capsizing
PublicationThe Second Generation Intact Stability Criteria (SGISC) are the latest achievements in the field of intact ship stability assessment. The criteria are the result of massive international cooperative efforts and extensive research that lasted more than 15 years. Even though they are based on a solid scientific foundation, the trial period has commenced to collect user experience and further validation. One of possible approaches...
-
Generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statku
PublicationOmówiono automatyczne generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statków. Na podstawie przyjętych założeń projektowych system ekspertowy zleca badania wybranych struktur podsystemów elektroenergetycznych statków. Aplikacja symulacyjna pobiera z biblioteki modele matematyczne elementów składowych struktur, a następnie zestawia modele symulacyjne, wykonuje badania...
-
The study of acoustic climate of the Southern Baltic
PublicationThis paper presents the statistical characteristics of seawater properties, which are necessary for predicting the propagation of acoustic waves in selected areas of the Baltic Sea. The statistics were elaborated based on long-term measurements of vertical distributions of sound speed, temperature, and salinity, and the nonlinearity parameter B/A. Nonlinear properties of the environment are considered, in connection...
-
Generation and Propagation of Nonlinear Waves in a Towing Tank
PublicationThe paper presents the results of the research focused on linear and nonlinear wave generation and propagation in a deepwater towing tank equipped with a single flap-type wavemaker of variable draft. The problem of wave generation and propagation has been theoretically formulated and solved by applying an analytical method; linear and nonlinear solutions were obtained. The linear solution has been verified experimentally. The...
-
Response Feature Technology for High-Frequency Electronics. Optimization, Modeling, and Design Automation
PublicationThis book discusses response feature technology and its applications to modeling, optimization, and computer-aided design of high-frequency structures including antenna and microwave components. By exploring the specific structure of the system outputs, feature-based approaches facilitate simulation-driven design procedures, both in terms of improving their computational efficiency and reliability. These benefits are associated...
-
Rapid EM-Driven Design of Compact RF Circuits By Means of Nested Space Mapping
PublicationA methodology for rapid design of RF circuits constituted by compact microstrip resonant-cells (CMRCs) is presented. Our approach exploits nested space mapping (NSM) technology, where the inner SM layer is used to correct the equivalent circuit model at the CMRC level, whereas the outer layer enhances the coarse model of the entire structure under design. We demonstrate that NSM dramatically improves performance of surrogate-based...
-
Assessment of cardiovascular risk in assisted living
PublicationWady i choroby układu krążenia są jedną z podstawowych przyczyn problemów zdrowotnych oraz przyczyn śmierci. Wczesne ich wykrycie jest szczególnie cenne jako, że może zapobiec przez poważnymi incydentami (np. zawał, udar, itp.). W artykule przedstawiono nasobny system pomiarowy integrujący wiele pomiarów przydatnych do oceny problemów kardiologicznych.Disorders of the heart and blood vessels are the leading cause of health problems...
-
A novel approach to energy safety improvement in the marine power plants with active power surge compensator
PublicationPaper raises a point of power surges and theirs adverse effects in the marine power plants. The article explains a source of surges appearance, and presents measurements carried out on a modern ship. It discusses effects of dynamic power transients on the ship’s energy safety. Finally it proposes, a novel approach for power surge elimination, based on medium voltage active conditioner. As well as it propose the topology and control...
-
The Development of a Combined Method to Quickly Assess Ship Speed and Fuel Consumption at Different Powertrain Load and Sea Conditions
PublicationDecision support systems (DSS) recently have been increasingly in use during ships operation. They require realistic input data regarding different aspects of navigation. To address the optimal weather routing of a ship, which is one of the most promising field of DSS application, it is necessary to accurately predict an actually attainable speed of a ship and corresponding fuel consumption at given loading conditions and predicted...
-
Procesualne kryteria oceny zrównoważonego projektowania architektonicznego
Publicationimportance of participation in sustainable design is constantly increasing, as sustainable design becomes a basic idea in architecture. thus mentioning of sustainable design process criteria is authorized. they consist of three following levels: 1) participation in design, 2) participation design, 3) participation design based on the consensus. there is differentia specifica of participation in participatory design because of...
-
Risk assessment for tram traffic on tramway bridges
PublicationMiejski transport szynowy wielu miastach stanowi istotny element systemu transportowego i jest przestrzennie rozwijającym się systemem zapewniającym mieszkańcom codzienną obsługę transportową. Bezpieczeństwo pasażerów transportu szynowego i użytkowników dróg jest jednym z najważniejszych czynników, który należy uwzględnić w trakcie projektowania infrastruktury oraz w ocenie operacyjnej systemu miejskiego transportu tramwajowego....
-
Variable-fidelity shape optimization of dual-rotor wind turbines
PublicationPurpose 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...
-
Modelling of performance of an AUV stealth vehicle. Design for operation.
PublicationIn the paper some results of research connected with modelling of performance and risk assessment of an AUV stealth vehicle are presented. A general approach to design of the stealth AUV autonomous underwater vehicle under consideration is introduced. The basic stealth characteristics of the AUV stealth vehicle are briefly described. The method of research is introduced. The AUV stealth vehicle concept is presented including the...
-
Modeling of performance of an AUV stealth vehicle. Design for operation.
PublicationIn the paper some results of research connected with modelling of performance and risk assessment of an AUV stealth vehicle are presented. A general approach to design of the stealth AUV autonomous underwater vehicle under consideration is introduced. The basic stealth characteristics of the AUV stealth vehicle are briefly described. The method of research is introduced. The AUV stealth vehicle concept is presented including the...
-
Economics of credit scoring management
PublicationCredit scoring models constitute an inevitable element of modern risk and profitability management in retail financial lending institutions. Quality,or separation power of a credit scoring model is usually assessed with the Gini coefficient. Generally, the higher Gini coefficient the better, as in this way a bank can increase number of good customers and/or reject more bad applicants. In...
-
Functional Safety and Cybersecurity Analysis and Management in Smart Manufacturing Systems
PublicationThis chapter addresses some of the issues of the integrated functional safety and cybersecurity analysis and management with regard to selected references and the functional safety standards: IEC 61508, IEC 61511, ISO 13849-1 and IEC 62061, and a cybersecurity standard IEC 62443 that concerns the industrial automation and control systems. The objective is to mitigate the vulnerability of industrial systems that include the information...
-
Corrosion degradation monitoring of ship stiffened plates using guided wave phase velocity and constrained convex optimization method
PublicationThe study presents an experimental investigation on the corrosion degradation level assessment using nondestructive wave-based methods. The degradation level of ship structural elements has been assessed in two different ways. The first one is based on the spectral decomposition and zero-crossing incorporated reconstruction of the dispersion curve approach of the antisymmetric Lamb wave mode and the best matching of the theoretical...
-
Assessing Tram Infrastructure Safety Using the Example of the City of Gdańsk
PublicationAnalysis of Gdańsk’s tram network statistics shows that incidents are quite frequent (about 650 within 5 years) and mostly involve collisions and crashes. As well as reducing the tram systems’ efficiency and reliability, incidents have a nega-tive effect on road safety. As Polish cities extend their tram networks, they must also ensure that their existing networks are safe. This is to be achieved by conducting safety assessments....
-
Ischemic stroke in general practice - risk factors, prognosis - prospective single center study
PublicationBackground. Ischemic stroke is one of the leading causes of death and disability in Poland, in the European Union and in the United States. Awareness related to the risk factors, particularly the modifiable ones, is of crucial importance in general practice and may improve early and long-term prognoses. Objectives. The aim of this study was to assess the risk factors and half-year survival rate in patients with ischemic stroke...
-
DETERMINATION OF THE AERODYNAMIC DRAG OF PNEUMATIC LIFE RAFTS AS A FACTOR FOR INCREASING THE RELIABILITY OF RESCUE OPERATIONS
PublicationEnsuring the safety of ship crews at sea is of the utmost importance. Life rafts are one of the basic components of any seagoing vessel and ensuring their stability is an important component of maritime research. This study concerns the determination of the aerodynamic drag coefficients of pneumatic life rafts in a full range of wind speed and directions. The drag coefficients are based on full-scale experimental studies and numerical...
-
Load capacity and serviceability conditions for footbridges made of fibre-reinforced polymer laminates = Warunki nośności i użytkowalności w odniesieniu do kładek z laminatów polimerowych
PublicationThe contribution is focused on derivation of the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) design criteria for footbridges built of fibre-reinforced polymer matrix (FRP) laminates. The ULS design criterion is based on the design guidelines for above-ground, pressure, FRP composite tanks and the Tsai-Wu failure criterion, which is used to predict the onset of FRP laminates damage. The SLS criterion is based...
-
Modelling of Curvature of the Railway Track Geometrical Layout Using Particle Swarm Optimization
PublicationA method of railway track geometrical layout design, based on application of cubic C-Bezier curves for describing the layout curvature is presented in the article. The control points of a cubic C-Bezier curve are obtained in an optimization process carried out using Particle Swarm Optimization algorithm. The optimization criteria are based on the evaluation of the dynamic interactions and satisfaction of geometrical design requirements.
-
Stability Analysis of the Floating Offshore Wind Turbine Support Structure of Cell Spar Type During its Installation
PublicationThe article presents the results of selected works related to the wider subject of the research conducted at the Faculty of Ocean Engineering and Ship Technology of the Gdansk University of Technology, which concerns design and technology of construction, towing, and settlement on the seabed, or anchoring, of supporting structures for offshore wind farms. As a result of this research, several designs of this type of objects were...
-
Scalability of surrogate-assisted multi-objective optimization of antenna structures exploiting variable-fidelity electromagnetic simulation models
PublicationMulti-objective optimization of antenna structures is a challenging task due to high-computational cost of evaluating the design objectives as well as large number of adjustable parameters. Design speedup can be achieved by means of surrogate-based optimization techniques. In particular, a combination of variable-fidelity electromagnetic (EM) simulations, design space reduction techniques, response surface approximation (RSA) models,...
-
A probabilistic-driven framework for enhanced corrosion estimation of ship structural components
PublicationThe work proposes a probabilistic-driven framework for enhanced corrosion estimation of ship structural components using Bayesian inference and limited measurement data. The new approach for modelling measurement uncertainty is proposed based on the results of previous corrosion tests that incorporate the non-uniform character of the corroded surface of structural components. The proposed framework's basic features are outlined,...
-
Rapid Variable-Resolution Parameter Tuning of Antenna Structures Using Frequency-Based Regularization and Sparse Sensitivity Updates
PublicationGeometry parameter tuning is an inherent part of antenna design process. While most often performed in a local sense, it still entails considerable computational expenses when carried out at the level of full-wave electromagnetic (EM) simulation models. Moreover, the optimization outcome may be impaired if good initial design is not available. This paper proposes a novel approach to fast and improved-reliability gradient-based...
-
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...
-
Architektura statków pasażerskich XX wieku.
PublicationArchitektura okrętów jako dyscyplina naukowa zajmuje się projektowaniem wnętrz oraz sylwet, jak również systematyką przestrzenną statków. Referat przedstawia rozwój architektury statków pasażerskich, które powstały w XX w. od momentu pojawienia się nowej dyscypliny naukowej – architektury okrętów, której prekursorami byli pracownicy Wydziału Architektury PG, aż do przełomu wieków XX i XXI. Statki pasażerskie ulegały przemianom,...
-
Experimental and Numerical Study on Dynamics of Two Footbridges with Different Shapes of Girders
PublicationThe paper presents the experimental and numerical results of the dynamic system identification and verification of the behavior of two footbridges in Poland. The experimental part of the study involved vibration testing under different scenarios of human-induced load, impulse load, and excitations induced by vibration exciter. Based on the results obtained, the identification of dynamic parameters of the footbridges was performed...
-
Pedestrian detection in low-resolution thermal images
PublicationOver one million people die in car accidents worldwide each year. A solution that will be able to reduce situations in which pedestrian safety is at risk has been sought for a long time. One of the techniques for detecting pedestrians on the road is the use of artificial intelligence in connection with thermal imaging. The purpose of this work was to design a system to assist the safety of people and car intelligence with the use...
-
High-resolution fire danger forecast for Poland based on the Weather Research and Forecasting Model
PublicationDue to climate change and associated longer and more frequent droughts, the risk of forest fires increases. To address this, the Institute of Meteorology and Water Management implemented a system for forecasting fire weather in Poland. The Fire Weather Index (FWI) system, developed in Canada, has been adapted to work with meteorological fields derived from the high-resolution (2.5 km) Weather Research and Forecasting (WRF) model....
-
The effects of selected factors on regional road fatalities – analysis of the Łódź region
PublicationAnalysis of regional accident records shows that a country’s national road safety programme does not have the same effect in each of its regions. What may be a serious problem in one region may be of marginal significance in another. Polish and international experience shows that main risk groups and types of accidents related to the level of development and quality of the road network differ from region to region. The conclusion...
-
EM-driven topology evolution for bandwidth enhancement of hybrid quadrature patch couplers
PublicationA broad operational bandwidth is one of the key performance figures of hybrid patch couplers. Due to the lack of systematic design procedures, bandwidth enhancement is normally obtained through manual modifications of the structure geometry. In this work, an optimization-based topology evolution for EM-driven design of patch couplers with enhanced bandwidth has been proposed. The method exploits a novel spline-based EM model where...
-
Fast Design Optimization of Waveguide Filters Applying Shape Deformation Techniques
PublicationThis paper presents an efficient design of microwave filters by means of geometry optimization using shape deformation techniques. This design procedure allows for modelling complex 3D geometries which can be fabricated by additive manufacturing (AM). Shape deforming operations are based on radial basis function (RBF) interpolation and are integrated into an electromagnetic field simulator based on the 3D finiteelement method (FEM)....
-
A Measurement-Based Approach for Speed Control of Induction Machines
PublicationThis paper presents an approach to design a measurement-based controller for induction machines. The proposed control approach is motivated by the fact that developing an appropriate mechanical model of such induction machines is a challenging task. Since our proposed control methodology is only on the basis of measured data, the controller design does not require any information about the model of the mechanical part. The control...
-
Selected elements of the methodology and method of designing amphibious flood rescue vehicles
PublicationThe methodology of designing amphibious flood rescue vehicles at the preliminary stage of the design process has been presented. The study has been focused on the properties of such vehicles when afloat, with their on-land behaviour and performance characteristics having been left aside. In the study, a general assumption has been made that the amphibious flood rescue vehicles should be designed as, above all, watercraft that additionally...
-
Fast Multi-Objective Antenna Optimization Using Sequential Patching and Variable-Fidelity EM Models
PublicationIn this work, a technique for fast multi-objective design optimization of antenna structures is presented. In our approach, the initial approximation of the Pareto set representing the best possible trade-offs between conflicting design objectives is obtained by means of sequential patching of the design space. The latter is a stencil-based search that aims at creating a path that connects the extreme Pareto-optimal designs (obtained...