[Show abstract][Hide abstract] ABSTRACT: The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time t on tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Q
[Show abstract][Hide abstract] ABSTRACT: Digital signal processing technology has revolutionized a way of processing, visualisation and interpretation of data acquired by underwater systems. Through many years side scan sonars were one of the most widely used imaging systems in the underwater environment. Although they are relatively cheap and easy to deploy, more powerful sensors like multibeam echo sounders and sonars are widely used today and deliver 3D bathymetry of sea bottom terrain. Side scan sonar outputs data usually in a form of grey level 2 D acoustic images but the analysis of such pictures performed by human eye allows creating semi-spatial impressions of seafloor relief and morphology. Hence the idea of post-processing the side scan sonar data in a manner similar to human eye to obtain 3D visualisation. In recently developing computer vision systems the shape from shading approach is well recognized technique. Applying it to side scan sonar data is challenging idea used by several authors. In the paper, some further extensions are presented. They rely on processing the backscattering information of each footprint (pixel in sonar image) along with its surroundings. Additionally, a current altitude is estimated from the size of shadow areas. Both techniques allow constructing 3D representation of sea bottom relief or other investigated underwater objects.
Preview · Article · Sep 2013 · Polish Maritime Research
[Show abstract][Hide abstract] ABSTRACT: GPS and Inertial Navigation Systems (INS) have complementary properties and they are therefore well suited for integration. The integrated solution offers better long-term accuracy than a standalone INS and batter integrity, availability and continuity or a stand-alone GPS receiver, making it suitable for demanding applications. The complementary features of INS and GPS are the main reasons why integrated GPS/INS systems are becoming increasingly popular. GPS/INS systems offer position, velocity, acceleration, attitude and angular velocity measurements with high accuracy, output rate and reliability in one package. In the paper integration algorithm of inertial sensors (accelerometers and gyroscopes) and GPS system data for the urban area personal navigation is presented. For data integration algorithm Extended Kalman Filter (EKF) is proposed.
[Show abstract][Hide abstract] ABSTRACT: Over the past sixty years of the “Transistor Era,” and increasingly during the integrated circuit “Moore's Law Era,” digital electronics has permeated into every aspect of the modern western lifestyle. However, to date, most embedded computer devices have either been purpose-built at great expense (e.g. ASICs), or the application code has been shoe-horned into general purpose computers designed for spreadsheets and word processing. Vital Electronics is the study and use of electrical components, circuits, networks, and systems to achieve a design goal of protecting, saving, and improving critical infrastructure and hence the quality of life. The paper focuses on the Vital Electronics curriculum aimed at building affordable trustworthy Embedded Systems.
[Show abstract][Hide abstract] ABSTRACT: The paper presents a web-based Geographic Information System (GIS) for assessment and visualization of Critical Infra structure
(CI) and its hazards which was developed by the Department of Geoinformatics at Gdansk University of Technology for the City
of Gdansk. The system allows spatial processing and mapping of various CI analysis results, with the CI analysis module based
on the CARVER2™ technology adapted to particular requirements of the Gdansk City Hall Crisis Management Department (CMD).
The system works as an integrated solution for both visualization of hazard scenarios and a team-enabled environment for information
analysis and sharing among geographically distributed decision makers. The paper focuses on the sample applications with reference
to the analysis, visualization, and mapping in a geographical context of several threat scenarios, such as blast attack, chemical
attack, and toxic leakage as well as the spatial distribution of critical infrastructure components in Gdansk, Poland.
[Show abstract][Hide abstract] ABSTRACT: The Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled images. The paper presents the concept of processing the Side Scan Sonar and Synthetic Aperture Sonar records for detailed reconstruction of 3D seafloor using Shape from Shading techniques. Shape from Shading is one of the basic techniques used in computer vision for the objects reconstruction. The algorithms proposed in the paper use the assumed Lambert model of backscattering strength dependence on incident angle and utilize additionally the information from shadow areas for solving obtained set of equations. The idea was verified by simulation study. The obtained results of 3D shape reconstruction are presented and the performance of the algorithms is discussed.
Preview · Article · Jun 2008 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: Nowadays, the techniques for 3D computer graphics are developing dynamically. They are finding application not only for creating computer games, but often for three-dimensional data visualization systems. Applying these techniques make graphical operations more effective and consequently these systems are more efficient. The paper presents the system for 3D seafloor visualization using multibeam sonar data. In the presented system three programming techniques for 3D graphic were used C++ OpenGL, Java3D, Java OpenGL. The problems related to the system development and the ways of its solution are presented.
[Show abstract][Hide abstract] ABSTRACT: The paper proposes combined spline-wavelet approach to the raw echoes seafloor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionally, wavelet bases have explicit mathematical expression in both the time and scale domain, which considerably facilitates their manipulation. In consequence, combined spline-wavelet decomposition seems to be useful in the seafloor imaging based on sonar data. It also provides better approximation, and versatile, compact representation, which results in data reduction. The suggested approach, however, introduces some side effects in the form of artifacts or oscillations on the edges of the decomposed image.
No preview · Article · Dec 2005 · Acta Acustica united with Acustica
[Show abstract][Hide abstract] ABSTRACT: The paper presents the prototype of safety-related application of the newly developed real-time, remotely accessible marine GIS for water pollution monitoring and emergency management supporting. The system is able to integrate many different types of marine pollution survey data, including those acquired by acoustic sensors. It processes the data extracted from acoustic echo signals and supports the instantaneous 2<sup>D</sup> and 3<sup>D</sup> visualisation and mapping of pollution aggregations (oil spills, discharge material plumes etc.). It also deals with the multi aspect data management and data analysis, and the prediction of the pollutants behaviour. The system makes use of the SQL database standard for data storage and the Scalable Vector Graphics (SVG) and Virtual Reality Modelling Language (VRML) for geographical objects remote presentation. Moreover, it requires only the WWW browser with SVG and VRML plug-in on the client side.
[Show abstract][Hide abstract] ABSTRACT: For the last decade multibeam sonars have been increasingly used for mapping and visualization of the seafloor to provide the ``physical bases'' for environmental studies. Increasing amount of digital (raster) echo records of high resolution from a multibeam sonar have enhanced the potential of computer modeling of the marine environment to improve our understanding of the bottom processes. However, the 3D bottom images as the result of merging different sonar transects do not comply exact geographical positions and should be corrected. Additionally, the raw sonar records are subject to systematic errors, random noise and outliers. In this paper, Kalman filtering techinque to generating optimal estimates of bottom surface from a noisy raw sonar records is proposed. The experiment on the surface indicates that after applying the Kalman filtering the outliers of raw records can be efficiently removed. Moreover, the two-step Kalman filtering method enables 3D seabed visualization in real time. The paper proposes the geographical corrections applied to the merged mutibeam sonar transects records. The 3D bottom relief before, and after the filtering method are presented.
No preview · Article · Oct 2003 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: Virtual reality techniques mainly developed for computer graphics had found numerous applications in various scientific areas like chemistry, astronomy, geography, etc. The paper proposes application of the virtual reality techniques in hydroacoustics for D visualization of data acquired by split-beam or multi-beam echosounders. Both types of echosounders allow for nonambiguous localization of targets in the water column and their imaging. As the multi-beam systems also delivers bathymetric information, in addition to imaging of the spatial distribution, it is possible to create complete virtual scene of sampled volume. Using builtin properties of Virtual Reality Modeling Language (VRML) it was possible to animate movement of fishes and other marine organisms in the water column. As the language is supported by Internet technology, its textlike description allows for easy rendering by most popular WWW browsers.
No preview · Article · Jan 2003 · The Journal of the Acoustical Society of America
[Show abstract][Hide abstract] ABSTRACT: The modern underwater acoustic equipment, like multibeam sonar, is able to provide the data which allows for unambiguous localization and also 3 D visualisation of targets of different kinds, including wracks, mines and other submerged objects. The large amount of information that seems to be useful for this purpose could also be extracted from side-scan sonar data, which has been collected over years within different survey regions. In this context, the paper concerns the development of side-scan data processing method for 3D reconstruction of seabed and its imaging. In the paper, two novel approaches are proposed. The first utilises the more accurate models of backscattering, including the differences in signatures of several types of objects. The second is based on definition and investigation of some quantitative descriptors of geometric features expected to be found in images of localised objects of artificial origin. The preliminary results obtained by application of these techniques to side-scan sonar data processing will be discussed in this paper. The results obtained from algorithmic processing of side-scan sonar images are compared to those obtained from multibeam system.
[Show abstract][Hide abstract] ABSTRACT: context, the paper concerns the development of side-scan data processing method for D reconstruction of seafloor and its imaging. In this paper, two novel approaches are proposed. The first utilises the more accurate models of backscattering, including the differences in signatures of several types of objects. The second is based on definition and investigation of some quantitative descriptors of geometric features expected to be found in images of localised objects of artificial origin. The preliminary results obtained by application of these techniques to side-scan sonar data processing will be discussed in this paper.
[Show abstract][Hide abstract] ABSTRACT: Side scan sonar is one of the most widely used imaging systems in the underwater environment. It is relatively cheap and easy to deploy, in comparison with more powerful sensors. Although side scan sonar does not provide seafloor bathymetry directly, its records are directly related to seafloor images. In the paper, the method for 3 D seafloor relief reconstruction from side scan sonar data is presented. The method is based on the Shape From Shading technique and for estimation of a bottom depth at a currently processed point, it uses the information from both currently processed and previous ping. The results obtained by several versions of the developed algorithm are presented. The obtained results are promising and also show how the performance of the proposed algorithm might be improved in further work.
[Show abstract][Hide abstract] ABSTRACT: The modern underwater acoustic equipment, like multibeam sonar, is able to provide the data which allow for unambiguous localization and also 3 D visualisation of targets of different kinds, including wrecks, mines and other submerged objects. The large amount of information that seems to be useful for this purpose, could also be extracted from side-scan sonar data, which has been collected over years within different survey regions. In this context, the paper concerns the development of simple side-scan data processing method for 3 D of wreck shape reconstruction and its imaging. The proposed method utilises two combined techniques: 1) the shape from shading (SFS) algorithm using several types of backscattering coefficient angular dependence function, and 2) the estimation of the elevation change using the dimension of acoustic shadow areas. The presented preliminary results are promising as they show quite good performance of the developed algorithm.