Passenger seaports are new starting-points of urban development. They form a new independent industry, become new incentives for improving urban infrastructure and increase the tourist attractiveness of the city itself and the region. In view of changes in passenger service processes, changes in route ferry and cruise networks, due to COVID-19, the heads of ports and terminals set new strategic tasks to determine the directions for infrastructure modernization and forecast development. The regions of the Adriatic and Baltic Seas were chosen as the experimental base. To find new answers, it is necessary to solve the problem of synthesizing the structure of a sea passenger port, taking into account all processes and services, the influence of the external environment, building a system of target functions and limiting conditions. Thus, the necessity of forming informed decisions on modernization based on the construction of new mathematical models is substantiated. A new function has been introduced that describes the influence of the external environment. Particular attention is given to the study of the mutual influence of the city and the sea passenger port in order to determine the need to improve transport accessibility and change the near-port transport space. The presented models of structure synthesis and target functions, models including functions of the influence of the external environment on the system “city infrastructure-sea passenger port-ferry company” allow at a qualitatively new level to solve the problem of forecasting development and form a system making decisions to improve the position of the passenger terminal in the sea region. The developed models and synthesis problem formation are applicable to sea passenger ports and terminals in other regions of the seas. The models are applicable both at the stage of creating a new marine terminal and during the study and subsequent modernization of the infrastructure. The presented new models allow the port manager to give answers to the questions of strategic development of sea passenger ports in sea regions.

Srećko Krile, N.N. Maiorov; Review, pp. 57-61 Download

The body shapes of aquatic animals can ensure a laminar flow without boundary layer separation at rather high Reynolds numbers. The commercial efficiencies (drag-to-weight ratio) of similar hulls were estimated. The examples of neutrally buoyant vehicles of high commercial efficiency were proposed. It was shown that such hulls can be effectively used both in water and air. In particular, their application for SWATH (Small Water Area Twin Hulls) vehicles is discussed. In particular, the seakeeping characteristics of such ships can be improved due to the use of underwater hulls. In addition, the special shaping of these hulls allows the reducing of total drag, as well as the energetic needs and pollution. The presented estimations show that a weight-to-drag ratio of 165 can be achieved for a yacht with such specially shaped underwater hulls. Thus, a yacht with improved underwater hulls can use electrical engines only, and solar cells to charge the batteries.

The purpose of this study is to show how coloured Petri nets can be used to select the crossing rules guaranteeing that two ships avoid collisions at sea in accordance with the international regulations on this matter. This paper is exclusively focused on the solution to this small sub-problem within the overall “Collision Avoidance System” that the authors of the present study are currently developing. For easier understanding, the overall system is also briefly presented. How the Petri net in the CPN Tools software is fed with “Real Time Real World” data is presented. These data are generated outside the Petri net from the function block to predict a possible collision and from the current meteorological data. We also demonstrate how the rule selections made by the Petri net are transferred from the CPN Tools software into the “Real Time Real World”. This transferred information is used outside the Petri net in the function block to calculate avoidance routes. The definition of the colour sets that are used and the individual operations applied to these colour sets in the coloured Petri net are presented.