RESUMEN
Maritime situational awareness at over-the-horizon (OTH) distances in exclusive economic zones can be achieved by deploying networks of high-frequency OTH radars (HF-OTHR) in coastal countries along with exploiting automatic identification system (AIS) data. In some regions the reception of AIS messages can be unreliable and with high latency. This leads to difficulties in properly associating AIS data to OTHR tracks. Long history records about the previous whereabouts of vessels based on both OTHR tracks and AIS data can be maintained in order to increase the chances of fusion. If the quantity of data increases significantly, data cleaning can be done in order to minimize system requirements. This process is performed prior to fusing AIS data and observed OTHR tracks. In this paper, we use fuzzy functional dependencies (FFDs) in the context of data fusion from AIS and OTHR sources. The fuzzy logic approach has been shown to be a promising tool for handling data uncertainty from different sensors. The proposed method is experimentally evaluated for fusing AIS data and the target tracks provided by the OTHR installed in the Gulf of Guinea.
RESUMEN
To obtain the complete operational picture of the maritime situation in the Exclusive Economic Zone (EEZ) which lies over the horizon (OTH) requires the integration of data obtained from various sensors. These sensors include: high frequency surface-wave-radar (HFSWR), satellite automatic identification system (SAIS) and land automatic identification system (LAIS). The algorithm proposed in this paper utilizes radar tracks obtained from the network of HFSWRs, which are already processed by a multi-target tracking algorithm and associates SAIS and LAIS data to the corresponding radar tracks, thus forming an integrated data pair. During the integration process, all HFSWR targets in the vicinity of AIS data are evaluated and the one which has the highest matching factor is used for data association. On the other hand, if there is multiple AIS data in the vicinity of a single HFSWR track, the algorithm still makes only one data pair which consists of AIS and HFSWR data with the highest mutual matching factor. During the design and testing, special attention is given to the latency of AIS data, which could be very high in the EEZs of developing countries. The algorithm is designed, implemented and tested in a real working environment. The testing environment is located in the Gulf of Guinea and includes a network of HFSWRs consisting of two HFSWRs, several coastal sites with LAIS receivers and SAIS data provided by provider of SAIS data.
RESUMEN
PURPOSE: Stylohyoid complex is anatomical structure predisposed to numerous individual variations. These may result in its extreme elongation, medial deviation and finally Eagle's syndrome occurrence. The aim of this study was to measure the length, angulation, evaluate morphological variations of stylohyoid complex by computed tomography and, subsequently, relate obtained data to the gender and the age of the evaluated cases. MATERIALS AND METHODS: The material included CT scans of stylohyoid complexes of 282 individuals. The entire length, maximal thickness, and angulation of the stylohyoid complexes in the coronal, transverse, and sagittal planes were measured. RESULTS: According to their morphology, orientation and length, stylohyoid complexes were classified into six morphological types. Elongated, bent, segmented, and segmented with attached stylohyoid ligament for the lesser horns of the hyoid bone stylohyoid complex types were characterized by significantly greater length, while pseudoarticulated type was characterized by significantly lower length in relation to normal stylohyoid complex type. The elongated type was additionally significantly thicker and with significantly lower value of medial angle in transverse plain than the normal stylohyoid complex type. Elongated, bent, and segmented types were significantly more frequent in males than in females. Furthermore, the frequency of the elongated stylohyoid complex type increased, whereas normal and pseudoarticulated types decreased with age. CONCLUSIONS: In conclusion, elongated and more medially deviated stylohyoid complexes are more frequent in males than in females. Their more frequent presence in the older age groups indirectly connects this phenomenon with the aging process.