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  • Szelangiewicz, Tadeusz; Żelazny, Katarzyna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    One of the methods of collecting polymetallic nodules from the sea floor is a hydraulic system using a single or double vertical pipeline. While mining, collecting pipelines suspended from a mining support vessel (MSV) move together. As a result of both the MSV’s motion with a suspended pipe system and water action (including deep-water currents) a vertical deflection and deformation occur along the pipeline. Simultaneously, stretching and bending tensions emerge along the pipeline. The article presents computer simulation results of vertical deflection and tensions within single and double vertical pipelines with fixed force from the ship’s movement (linear movement at constant speed) and regular force from the waves.
  • Zalewski, Paweł (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Vessels conducting dynamic positioning (DP) operations are usually equipped with thruster configurations that enable the generation of force and torque. Some thrusters in these configurations are deliberately redundant to minimize consequences of thruster failures, enable overactuated control and increase the safety in operation. On such vessels, a thrust allocation system must be used to distribute the control actions determined by the DP controller among the thrusters. The optimal allocation of the thrusters’ settings in DP systems is a problem that can be solved by convex optimization methods depending on the criteria and constraints used. This paper presents a quadratic programming (QP) method, adopted in a DP control model, which is being developed in Maritime University of Szczecin for ship simulation purposes.
  • Baldauf, Michael; Mehdi, Raza; Fischer, Sandro; Gluch, Michael (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Avoidance of collisions is one of the most important tasks for the officer of the watch on a ship’s bridge. Measures and actions required to avoid such accidents are described in the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs) adopted by the International Maritime Organization (IMO) in 1972 and still valid, with several minor amendments, since then. On the basis of a proper look-out at all times, by sight and hearing, and the use of all available means, also including technical equipment installed on-board as well as information provided by a Vessel Traffic Service (VTS), the navigating officer collects traffic and environmental data and combines them with their own ship data to construct a mental traffic image for the assessment of risk of collision with other objects in the vicinity. In the case wherre there is an unacceptable risk she or he has to decide on taking action. In most of the cases decision making is appropriate to the prevailing circumstances and ships maneuver and pass at a safe distance. Only in very rare cases, due to whatever reasons, watch officers fail in taking appropriate actions in good time. It is assumed that, if effective alerting algorithms would be available, a substantial number of collisions at sea, and especially in coastal waters, can be avoided by making the watch officer aware that the ‘last line of defence’ for taking action is close to come. It is assumed that there is potential in applying the principle of the resolution advisory alert of an ACAS (Airborne Collision Avoidance System)/TCAS (Traffic Alert and Collision Avoidance System) in aviation and adapt it to the needs of maritime traffic. In this paper, the authors introduce a method for triggering collision warnings by focusing specifically on the critical last phase of an encounter and taking into account the maneuvering characteristics of the navigating ship. They comprehensively explore the application using scenario studies discussing the operational aspects of varying implementation states (one ship only, SOLAS ships only).
  • Filipowicz, Włodzimierz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Nautical measurements are randomly and systematically corrupted. There is a rich scope of knowledge regarding the randomness shown by results of observations. The distribution of stochastic distortions remains an estimate and is imprecise with respect to their parameters. Uncertainties can also occur through the subjective assessment of each piece of available data. The ability to model and process all of the aforementioned items through traditional approaches is rather limited. Moreover, the results of observations, the final outcome of a quality evaluation, can be estimated prior to measurements being taken. This a posteriori analysis is impaired and it is outside the scope of traditional, inaccurate data handling methods. To propose new solutions, one should start with an alternative approach towards modelling doubtfulness. The following article focusses on belief assignments that may benefit from the inclusion of uncertainty. It starts with a basic interval uncertainty model. Then, assignments engaging fuzzy locations around nautical indications are discussed. This fragment includes transformation from density functions to probability distributions of random errors. Diagrams of the obtained conversions are included. The presentation concludes with a short description of a computer application that implements the presented ideas.
  • Hajduk, Jerzy (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    When a transport vehicle is put into service on a new route, all safety aspects of its movement should be comprehensively examined. In maritime transport, such situations arise especially when new sea ports are built, intended to handle selected types of vessels with specific characteristics. The construction of the LNG terminal in Świnoujście made it necessary to carry out an extensive analysis of the safety of LNG tanker passage. This was related to the shipping route from the Danish Straits to the berth. This article compares the routes planned at the design stage with the actual track of the tanker Al Nuaman during its first voyage. The tanker speeds on key route sections have been examined, i.e. in the approach channel from Cape Arkona to Świnoujście.
  • Jaskólski, Krzysztof (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Due to safety reasons, the movement of a ship in coastal areas should be monitored, tracked, recorded, and stored. The Automatic Identification System (AIS) is a suitable tool to use in performing these functions. The probability limit for the AIS dynamic data availability can be limited by the lack of a Global Position System (GPS) signal, heading (HDG), and rate of turn (ROT) data in the position report. The unavailability of a data link is an additional limitation. To fill this gap, it is possible to attach the discrete Kalman filter (KF) for the position and course estimation. Coordinate estimation in the absence of a transmission link can improve the quality of the AIS service at Vessel Traffic Service (VTS) stations. This paper has presented the Kalman filtering algorithm to improve the possibilities for ship motion tracking and monitoring in the TSS (Traffic Separation Scheme) and fairways area. More than 570 iterations were calculated and the results have been presented in figures to familiarize the reader with the operating principle of the Kalman filter algorithm.
  • Wołejsza, Piotr; Eric, Kulbiej (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article aims to depict the fundamentals of passage planning and route management for an autonomous vessels (AV). It presents a derivation of such a voyage passage plan, its step-by-step analysis, and a comparison to its conventional equivalent. This passage plan consists of four major parts: dock and harbour, en route, approach, and mooring stages. The whole activity of passage planning itself may be divided into the following stages: appraisal, planning, execution, and monitoring. The paper concludes with an overview of potential future applications and use of mentioned content.
  • Guze, Sambor (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    One of the possibilities when modelling a transport network is to use a graph with vertices and edges. They represent the nodes and arcs of such a network respectively. There are dozens of parameters or characteristics that we can describe in graphs, including the different types of domination number and the problems related to it. The main aim of this paper has been to show the possibilities of the application of the selected domination- oriented concepts to modelling and improving the transportation and/or logistics networks. Firstly, the basic description of domination in graph theory has been introduced. The edge-subdivision and bondage number notations and their implementations to the transportation network description and modelling were then proposed. Furthermore, the possible usage of distinguishing concepts in an exemplary academic transportation network has been shown. Finally, the conclusions and future directions of the work have been presented.
  • Kujawski, Artur; Stępień, Grzegorz (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents the results of research on determining inland vessel position using a single stationary, non-metric camera, which was positioned on the Długi Bridge in Szczecin. Studies included a comparison of graphical methods (i.e. geometric transformation and the bunch of rays method) and analytical methods (i.e. 2D to 2D transformation and 3D to 2D transformation). The research material was a collection of video images of an inland vessel navigating the West Odra River between the Długi and Kolejowy bridges in Szczecin. The results of the research were compared to reference points determined using tachymetric surveys and material acquired by an Unmanned Aerial Vehicle (UAV) and the onboard GNSS satellite receiver with Real Time Kinematic (RTK) correction.
  • Lewitowicz, Jerzy; Szelmanowski, Andrzej; Pazur, Andrzej; Michalak, Sławomir; Janik, Paweł (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The paper presents selected results of analytical and construction works executed at the Air Force Institute of Technology (AFIT) in the context of possibilities of supporting the actions of a helicopter crew, i.e., pilot-crew commander, pilot-operator of on-board systems, and on-board technician participating in aviation/maritime search and rescue missions. Such support is based on using the helmet-mounted display systems SWPL1 “Cyklop” and NSC1 “Orion” for information from the observation-targeting heads and verbal communication with the survivor. Selected imaging and verbal communication devices installed on aircraft operated by the Polish Armed Forces, which are used in aviation/maritime search and rescue actions, are discussed. Particular attention is drawn to the problems associated with the integrated avionics systems of helmet-mounted imaging of piloting-navigation parameters and the helmet-mounted imaging of information from the observation-targeting heads, i.e., the on-board radio direction finder system and emergency radio, which are part of the integrated communication system. Sample structural solutions for such systems and the possibilities of their application in search and rescue missions are presented
  • Mąka, Marcin; Majzner, Piotr (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The article proposes a model of the system supporting the decision-making process relating to the radio operator on board a ship after a distress alert is received by a Digital Selective Calling (DSC) controller working on VHF channel 70. The model is aimed at the implementation into the system of radiocommunication event management. The system takes into account the existing Radio Regulations. The model makes use of Petri nets, which are elements of graph theory. The time domain is comprised in the developed graph, and the states (places) and transitions capable of autonomous functioning are separated, as are those places and transitions requiring direct operator action based on empirical knowledge.
  • Wawruch, Ryszard (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    According to the International Maritime Organisation (IMO) recommendation, when the target data from the automatic identification system (AIS) and radar tracking are both available and the association criteria are fulfilled such that the AIS and radar information are considered for one physical target, then as a default condition of radar equipment, the AIS target symbol and the alphanumerical AIS target data, including information on the closest point of approach (CPA) and time needed to reach the CPA (TCPA) should be automatically selected and displayed as this is more accurate than radar tracking data as the current values of true and relative vectors of a manoeuvring object can be presented without time delay which is characteristic for radar tracking. Research conducted at sea on two ships using real navigational equipment has shown that sometimes onboard AIS presents CPA of other vessels equipped with this device as unstable and inaccurate as the automatic radar plotting aid (ARPA). The source of these instabilities and inaccuracies is to be discovered and thus implemented into radar-navigational simulators used for radar training at operational and management levels. This article briefly describes the encountered inaccuracy and instability of the values of the CPA of the encountered vessel presented by AIS, on current shipboard systems, and the possibilities of their demonstration on simulation devices.
  • Chybowski, Leszek; Gawdzińska, Katarzyna (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Selected issues of component importance analysis for complex technical systems have been presented in this paper. A generic example of a complex technical system and selected statistics of operating losses have been described. A description and diagrams of both qualitative and quantitative importance analysis have also been included. The most significant problems facing complex technical system modelling have been pointed out. A multi-criteria system component importance analysis and the basic criteria for a system component quality evaluation have also been introduced. Some factors influencing the importance of the technical system’s components have also been described. Finally, the necessity of further developing importance analysis methods for machinery operation has been highlighted.
  • Ochin, Evgeny (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The idea of C/A codes GPS/GNSS Spoofing (Substitution), or the ability to mislead a satellite navigation receiver into establishing a position or time fix which is incorrect, has been gaining attention as spoofing has become more sophisticated. Various techniques have been proposed to detect if a receiver is being spoofed – with varying degrees of success and computational complexity. If the jammer signals are sufficiently plausible then the GNSS receiver may not realize it has been duped. There are various means of detecting spoofing activity and hence providing effective mitigation methods. In this paper, a novel signal processing method applicable to a single antenna handset receiver for spoofing detection has been described. Mathematical models and algorithms have been developed to solve the problems of satellite navigation safety. What has been considered in the paper is a spoofing detection algorithm based on the analysis of a civil satellite signal generated by mobile C/A GPS/GNSS single-antenna receivers. The work has also served to refine the civilian spoofing threat assessment by demonstrating the challenges involved in mounting a spoofing attack.
  • Sanecki, Józef; Klewski, Andrzej; Zygmunt, Marek; Stępień, Grzegorz; Hałaburda, Roman; Borczyk, Kamil (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents the problem of surveying landslide prone areas. Discussed are the possibility of using photogrammetry methods for digital imaging, creating Digital Terrain Models (DTM) and Digital Elevation Models (DEM) of slope surface and combining these with the ground’s angle of internal friction, cohesion and hydrogeological data. Unmanned Aerial Systems (UASs) with inclined high precision cameras show different slope angles than UASs with vertical cameras. Expressly, we can see places within the landslide area where the angle of internal friction and cohesion are low. These places are the most likely to suffer further mass movements causing fissures and ground displacements. In the observed landslide area we separated the steep parts of the slope, with low cohesion values, and the slight parts of the slope, with low values of angle of internal friction. In these different areas, landslides can evolve in different ways and at different speeds. The Factor of Safety (FS) was calculated for different types of area which allowed the probability of new mass movements to be checked for different areas. This method can be useful for C-B and X-Band PSI Interferometry Data. Because of the damage potentially incurred by landslides, there is a need to better understand these natural phenomena, especially their methods and speed of development and how they can be prevented from forming in the future.

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