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  • Kazerooni, Mohammadreza Fathi; Seif, Mohammad Saeed (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The calculation of unknown hydrodynamic derivatives of the equations of motion is the first step to estimate ship maneuverability and dynamic stability. These derivatives can be obtained theoretically, experimentally and numerically. Despite the development of the oblique towing model test to measure the hydrodynamic derivatives of displacement ships, limited experimental results are available for hydrodynamic derivatives of high speed crafts and speed dependency of the hydrodynamic derivatives is not understood well. In this paper a systematic series of model tests is described to determine the effect of forward speed on hydrodynamic derivatives of a monohull planing craft and the variations of the hydrodynamic derivatives by forward speed are derived. According to the results, hydrodynamic derivatives of planing hull are dramatically changed by variations of forward speed. Moreover, it is not possible to introduce a constant hydrodynamic derivative in the all the ranges of drift angle. Thus, the method of known constant hydrodynamic derivatives is not applicable to the simulation of planing craft maneuvering and variable hydrodynamic derivatives should be applied.
  • Nozdrzykowski, Krzysztof; Komorowski, Adam (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article describes the construction and principles of operation of a prototype energy-converting machine – a flow machine with pistons rotating in toroidal spaces. A comparative analysis of the results of simulation and experimental tests of fluid flow resistance in the presented prototype machine has been performed with the use of correlation and integral calculi. The article also presents a comparative analysis of the volumetric efficiency of the examined pump and of a Vogelsang pump with similar design and size. The present state of the research makes it possible draw conclusions about the high exploitation value of the proposed pump construction. For this displacement pump, performance increases along with rotational speed. However, it is different from other pumps by virtue of is simple and compact construction as well as greater capacity in relation to its size.
  • Stefanowski, Andrzej (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This article presents the problem of overloading of the steering gear controlled by an autopilot in high sea states and ways of reducing it. The author proposes a new method of estimating the steering gear load by counting the number of machine reversals in a selected time period. A block diagram of such solution is presented along with the results of simulations of system operation in different sea states. The results obtained, in terms of number of reversals, depend significantly on the state of sea, providing a means to estimate the current state of the sea as well as the expected difficulty in exploiting the steering gear.
  • Kałkowska, Elwira (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Due to the accelerating demand for transporting raw materials around the world over the last century, bulk carriers are being constantly developed in order to maximise their capacity and efficiency whilst maintaining safety and durability of the vessels. With regards to safety, the International Maritime Organisation (IMO) and the International Association of Classification Societies (IACS) recurrently issue regulations and technical standards for the design and construction of ships, in order to safeguard the crew and other people on board. In light of these regulations, three issues concerning the properties of a bulk carrier are investigated. Firstly, the floodability of a bulk carrier is researched, to determine the largest possible volumes of compartments which can be flooded without causing the bulk carrier to capsize. Results were determined both manually and by means of marine design software, Maxsurf Enterprise; results generated by the two methods are compared. Additionally, a series of loadcases, each consisting of a different cargo and ballast configuration, are sought to reveal their effect on both the still water bending moment and the intact stability of the vessel. The results are analysed in relation to the IMO’s criteria.
  • Pleskacz, Krzysztof (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The author presents a new perspective on the process of controlling course indicators, to fit with the modern equipment of present day ships, in line with current trends and prospects for its development. The newly proposed measures and methods in this research must address the following issues: the improvement of safety, reduction in routine work and improvement of the navigation services on a ship. This article includes an analysis of requirements and also test results relating to compliance with respect to the course indicators used on commercial vessels. The author presents and justifies the need to introduce changes to the procedures and practices of conduct, updating the current actual situation. The proposed new procedures should have a direct impact on the security of navigation.
  • Filipek, Wiktor; Broda, Krzysztof (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    In this article the authors discuss the concept of using pyrotechnical materials for transportation in deep sea environment. The use of pyrotechnical materials in underwater transportation involves their use as a source of energy (needed, for instance, in emptying the ballast tank). The authors presented the experimental verification of the usefulness of pyrotechnical materials in transporting from great depth. In the experiments, a modified composition black powder was used as source of energy. In the research the authors focused on two methods of controlling the pyrotechnical reaction effects, i.e., mechanical suppression of the blast, so as to reduce its negative effect on the housing of the transporter, and control of the pyrotechnical reaction itself. The obtained results confirm the possibility of using pyrotechnical materials in transportation of deposits from considerable depth. Introduction Ongoing depletion of land mineral resources and, on the other hand, an increase in the consumption of some raw materials cause an increasing interest in underwater exploitation of mineral resources. This is an impulse for increasingly intensive research and development of mineral resource technology exploration from sea and ocean floors. The scope of this interest includes not only crude oil and natural gas. Sea mining of the shelf area (Karlic, 1984; Depowski et al., 1998) provides many metal materials, such as titan, zircon, tin, gold, platinum and iron sands. Diamond, phosphorite, gravel and sand deposits have been effectively explored, not to mention such resources as sulphur and bituminous coal deposits. Great hopes are pinned upon extensive land polymetallic nodules and seafloor massive sulphides (SMS) (SPC,
  • Kazimierski, Witold; Zaniewicz, Grzegorz; Bodus-Olkowska, Izabela (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Mobile devices are increasingly popular among recreational water users and for navigational purposes. Making full use of the possibilities they offer requires a navigational system to be designed and built for mobile devices which make use of mobile cartography. A dynamically adaptive mobile presentation model offering various display possibilities may be an appropriate example of such a system. The navigational purpose of the system, however, requires that the main navigational data presented are integrated in one place, in a so-called conning display. These data should be easily accessible to the user, which is not always the case with mobile devices. The idea of using a Head-Up Display (HUD) as a conning display in a mobile navigation system arose from these considerations. The current paper presents research on implementing a HUD into a mobile system. First, the idea of mobile cartographic presentation is discussed, then the navigational data available in the system are presented. Finally, the concept of using a HUD is explained, a HUD presentation model is shown and technical aspects of HUD integration are described.
  • Orymowska, Joanna; Sobkowicz, Paulina (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    The most important aspect of the transport of goods by water, including inland waterways, is navigational safety. Formal Safety Assessments (FSAs) are widely-adopted methods of risk analysis used to assess safety. By defining potential risks and describing event scenarios, FSAs allow the estimation and minimization of the level of risk of individual events. The current article presents the characteristics of accidents on inland waterways and the classification of accidents, with a discussion of their effects. After analysis, the research area was narrowly defined to vessels passing under bridges, and the threats arising from barges descending from the axis of the fairway. On the basis of the analysis, the authors have offered a risk assessment model of inland vessel collision with some element of navigational infrastructure during under-bridge passage. Event Tree Analysis (ETA) was used to carry out hazard identification.
  • Orymowska, Joanna; Sobkowicz, Paulina (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Navigational safety of inland vessels in the Międzyodrze and Szczeciński Węzeł Wodny area
  • Głogowski, Piotr; Igielski, Karol; Orymowska, Joanna; Pilip, Karolina (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Accidents, breakdowns or incidents threatening both human life and the environment are inherent parts in operating in the offshore sector. Regular monitoring and analysis of all kinds of events are important to isolate the most common and dangerous ones, to be able to prevent them in the future. The article summarizes the sources containing information regarding accidents occurred in the maritime offshore sector. Due to their widespread and easy access, the article is focused on electronically published databases and safety reports concerning the risk and dangers related to the implementation of marine exploration – mining projects. Based on these data, the authors made analyses, presented statistics and proposed ways to minimize threats in the offshore sector of the marine industry.
  • Klink, Janusz; Uhl, Tadeus (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    This paper focuses on factors affecting the dimensioning of Short Message Service (SMS) systems in mobile communications networks. Problems associated with Quality of Service (QoS) in modern communications networks in general are described, along with the main parameters that define QoS in SMS systems. The functionality of the SMS in terms of European Telecommunications Standards Institute (ETSI) standards is then explained. The creation of a queuing model is described for an SMS system which is based on ETSI documentation and will be analysed in calculations. The parameter completion rate plays an important role in SMS. Practical aspects of the End-to-End (E2E) delivery time for SMS systems are also discussed. The approach suggested in this paper and the insights gained in the course of this work can be of valuable practical use in the planning and analysis of real SMS systems.
  • Mahmoodi, Kumars; Ghassemi, Hassan; Nowruzi, Hashem (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Ocean wave energy is known as a renewable energy resource with high power potential and without negative environmental impacts. Wave energy has a direct relationship with the ocean’s meteorological parameters. The aim of the current study is to investigate the dependency between ocean wave energy flux and meteorological parameters by using data mining methods (DMMs). For this purpose, a feed-forward neural network (FFNN), a cascade-forward neural network (CFNN), and gene expression programming (GEP) are implemented as different DMMs. The modeling is based on historical meteorological and wave data taken from the National Data Buoy Center (NDBC). In all models, wind speed, air temperature, and sea temperature are input parameters. In addition, the output is the wave energy flux which is obtained from the classical wave energy flux equation. It is notable that, initially, outliers in the data sets were removed by the local distribution based outlier detector (LDBOD) method to obtain the best and most accurate results. To evaluate the performance and accuracy of the proposed models, two statistical measures, root mean square error (RMSE) and regression coefficient (R), were used. From the results obtained, it was found that, in general, the FFNN and CFNN models gave a more accurate prediction of wave energy from meteorological parameters in the absence of wave records than the GEP method.
  • Górzański, Marek; Łączkowski, Marceli (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    W pierwszej naszej pracy z cyklu dotyczącego badań własności fizykomechanicznych linek stilonowych i torlenowych podane zostały dane liczbowe, które stanowią podstawę do porównawczej charakterystyki wytrzymałościowej części plastrowej włoka, wykonanej z linek stilonowych lub torlenowych.
  • Jaworski, Stefan Leszek (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Omówiono warunki awansu zawodowego, szczególnie w latach 1948-1953. Wzięto pod uwagę organizację nauki, liczebność absolwentów i politykę kadrową. Stwierdzono, że podstawową grupą uwarunkowań dotyczącą awansu zawodowego związana była ze stanem i rozwojem floty żeglugowej, ocenianych w 3 charakterystycznych podokresach rozwojowych lat 1946-1977.
  • Krupowies, Jan; Łączkowski, Marceli (Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie, )
    Zbadano niektóre własności fizykomechaniczne przędzy rybackiej, wytworzonej przez wielostopniowe skręcenie profilowanych włókien polikaproamidowych /lanastilowych/ i stwierdzono, że są one gorsze od tychże własności zbliżonej masą liniową, średnicą i skrętem przędzy z nieprofilowanych włókien tego samego rodzaju /stilonowych/.

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