The application of fuzzy logic is an effective approach to a variety of circumstances, including solutions to maritime anti-collision problems. The article presents an upgrade of the radar navigation system, in particular, its collision avoidance planning tool, using a decision model that combines dynamic parameters into one decision%the collision avoidance course. In this paper, a multi-parametric decision model based on fuzzy logic is proposed. The model calculates course alteration in a collision avoidance situation. First, the model collects input data of the target vessel and assesses the collision risk. Using time delay, four parameters are calculated for further processing as input variables for a fuzzy inference system. Then, the fuzzy logic method is used to calculate the course alteration, which considers the vessel's safety domain and International Regulations for Preventing Collisions at Sea (COLREGs). The special feature of the decision model is its tuning with the results of the database of correct solutions obtained with the manual radar plotting method. The validation was carried out with six selected cases simulating encounters with the target vessel in the open sea from different angles and at any visibility. The results of the case studies have shown that the decision model computes well in situations where the own vessel is in a give-way position. In addition, the model provides good results in situations when the target vessel violates COLREG rules. The...
COBISS.SI-ID: 49241091
Cruise shipping has been extremely popular in recent years, and one of the fastest-growing areas has been the Mediterranean. In the paper, we examine the evaluation of possible competitive–cooperative relationships among Mediterranean cruise ports for the period 2000–2017. To this end, we use three models: the dynamic shift-share model, the Lotka–Volterra model (LVM), and the logistic model (LM). The evaluation of basic market indices is included for completeness. The analysis shows that cruise traffic is in a saturation phase. The shift-share and LVM models reveal that interaction among ports is not significant for the large ports, but could be essential for the small ones
COBISS.SI-ID: 17866499
In this article, we discuss the effects of touchdown on an inclined seabed of a mooring system consisting of one or two chains joined at the sinker that is subjected to horizontal tension or tension at the suspension point. We modeled the statics of the system using the classical non-extensional catenary theory. For a system without a sinker, we provide an analytical solution for the governing equations, whereas for a system with a sinker, we derive governing equations that can be solved only numerically. Analytical formulae for the calculation of the restoring coefficient of the system are also provided. Numerical examples and a real case of mooring buoy design illustrate the use of the proposed model.
COBISS.SI-ID: 2892131
Understanding the factors that might intentionally influence the reception of global navigation satellite system (GNSS) signals can be a challenging topic today. The focus of this research is to evaluate the vulnerability of geodetic GNSS receivers under the use of a low-cost L1/E1 frequency jammer. A suitable area for testing was established in Slovenia. Nine receivers from different manufacturers were under consideration in this study. While positioning, intentional 3-minute jammings were performed by a jammer that was located statically at different distances from receivers. Furthermore, kinematic disturbances were performed using a jammer placed in a vehicle that passed the testing area at various speeds. An analysis of different scenarios indicated that despite the use of an L1/E1 jammer, the GLONASS (Russian: Globalnaya Navigatsionnaya Sputnikovaya Sistema) and Galileo signals were also affected, either due to the increased carrier-to-noise-ratio (C/N0) or, in the worst cases, by a loss-of-signal. A jammer could substantially affect the position, either with a lack of any practical solution or even with a wrong position. Maximal errors in the carrier-phase positions, which should be considered a concern for geodesy, differed by a few metres from the exact solution. The factor that completely disabled the signal reception was the proximity of a jammer, regardless of its static or kinematic mode.
COBISS.SI-ID: 2963811
This paper describes a an upgraded research effort to develop a new technology for safe docking at container terminals – 2d laser docking integrated with AIS and metoceanic data. What appears to be, and perhaps sometimes is, a simple process is nevertheless potentially hazardous to the environment and personnel. The timing of the development of this system is all the more fortunate given the port's continuing pressure to accommodate larger vessels, particularly container ships. The port's adaptation has been made possible by a complex array of technologies, ranging from simple dredging to sophisticated presentation of data to pilots and shipping authorities.
COBISS.SI-ID: 15025923