Boris Petelin

The dissertation provides a contribution to the field of spatial-temporal data mining, which is a response to the enormous amount of data collected in operational and research databases worldwide. The advantage of spatial-temporal data mining compared to traditional methods is the appropriate treatment of spatial and temporal attributes and consequently the ability to discover hidden information which is contained in databases. The dissertation is limited to spatial-temporal data mining in the earth sciences, or more precisely, we have developed a methodology that upgrades methods of the Lagrangian particle tracking of moving virtual water parcels in the ocean. By using classic Lagrangian analysis, we examine paths or trajectories of simulated water parcels by visual inspection or by using various statistical methods as well as other approaches (i.e. dynamic system theory, stochastic modeling etc.). In the field of oceanography, which is the primary data source for the dissertation, high-quality numerical modeling is becoming increasingly important. Based on the velocity fields in the results of such a model, we first produce a number of trajectories of virtual particles (typically around 100,000). In the next step, we subdivide the model domain into smaller areas and search for spatial-temporal association rules that enable us to obtain the probability of the transition of virtual particles from individual sea areas to neighboring ones within the specified time interval. We visualize the resulting rules in the form of multi-level directed graphs with different granulation in space and time. We can add any attributes to the edges and vertices in such graphs, which represent aggregated or statistical information, or oceanographic or other material. The resulting multi-level directed graphs are open to numerous algorithms that are used for graph mining. Our contribution is the algorithms for searching significant structures (paths and cycles) in these graphs. First we uncover simple cycles that occur in short periods of time (one month) within one graph, though more realistic paths and cycles occur over longer periods, that is, several months or even years. In the dissertation, we deal with paths and cycles that extend into periods of several months but less than one year. We deal with simulations which are too short to detect longer term processes and this results in dynamic paths. For the construction of these paths and cycles, we must take into account that the weights of graphs change over time, so the resulting paths and cycles are called dynamic. We perform hierarchical clustering of the resulting dynamic paths and cycles based on the distance between them and obtain dynamic fuzzy paths and cycles and compare them with the structures that are known from oceanographic observations provided by domain experts. The results in the dissertation show the significant similarity of obtained dynamic fuzzy paths and cycles with the observations and prior knowledge of oceanographic experts. The methodology, described in the dissertation, is a solid basis for the development of applications that upgrade the established methods used by oceanographic experts. In chapter 6 of the dissertation, we present some examples of successful applications of multi-level directed graphs. Thus, we show that the movement of water masses in the Mediterranean Sea has a seasonal nature with a period of 12 months. In addition, by using multi-level directed graphs we present long-term transient phenomena such as the circulation reversal in the Ionian Sea, which occurs approximately every 10 years. By using additional attributes (e.g. wind power) in multi-level directed graphs, we show the correlation of the probability of movements of water masses with these attributes. Finally, multi-level directed graphs are a solid basis for modeling the dispersal of biological species.

The second year of the project was mainly devoted to intense CTD cruises at stations that are in the frame of the coastal observing network in the Gulf of Trieste. Two project partners, LBM of Trieste, Italy and NIB.MBS of Piran, Slovenia, conducted 36 cruises over a one-year ...

ABSTRACT Understanding animal movement patterns is not only important for providing insight into their biology, but is also relevant to conservation planning. However, in aquatic and wide-ranging species such as cetaceans, this is often difficult. The common bottlenose dolphin ( Tursiops truncatus ) is the most common cetacean in the northern and central Adriatic Sea and has been the focus of long-term studies in some areas. All of the studied local populations show a relatively high degree of site fidelity, but their movements, ranging patterns or connectivity are not well understood. On 24 and 26 April 2014 a single adult bottlenose dolphin was observed and photographed alive off the Slovenian coast. The same individual was found dead on the shores of Goro, Italy, on 5 May 2014, about 130 km from the two sighting locations. The well-marked dorsal fin made the identification straightforward. The dolphin was found freshly dead, suggesting it had died very recently prior to being found. This indicates that the reported movement was a real one, rather than an artefact of currents. Although single cases cannot provide the basis for making population-level inferences, our observation shows that northern Adriatic bottlenose dolphins can make substantial movements in short periods of time and suggests that such movements could be more common than currently documented. Comparisons among photo-ID catalogues and stranding events can be highly informative, as they can provide useful information with implications for the cross-border conservation of mobile marine predators.

Three representative cases studies on the effect of bora wind episodes (1.5-2 days duration with wind speeds over 10 m s-l) on surface water pCO2 and 02 in the coastal Northern Adriatic are presented, and in all three studied cases, regardless of pre-bora conditions, pC02 suddenly increases by 30-50 muatm a few hours after the onset of bora. We estimate that these winds increased the flux of CO2 from the atmosphere into the ocean on an annual time scale by more than 30% at this location. Our study contributes to a very limited set of observations currently available on the biogeochemical response to episodic high wind events in costal areas and their role in CO2 exchange.

In this paper we consider the problem of predicting the state of tardy production in a manufacturing environment by the use of neural networks. Two approaches are proposed and compared and these are in turn compared with a linear auto-regressive model.

Numerical simulations of the winter circulation in and around the Gulf of Trieste are presented. The model, based on the architecture of the Princeton Ocean Model, gave reasonable results for circulation in the Gulf during the winter period, when the dominant bora wind is ...

In three towns along the Siovenian littoral municipial sewage is treated mechanically. Municipial wastewater from the town of Koper empties into the estuary of the small Riiana River (annual mean flow is less than 5 m3/s), the wastewater from the town of Piran empties into the sea ...