Libs in cultural heritage: recognition and identification of objects in an underwater archaeological shipwreck

Nowadays, one of the most important areas of interest in archeology is the characterization of the submersed cultural heritage. Mediterranean Sea is rich in archaeological findings due to storms, accidents and naval battles since prehistoric times. Chemical analysis of submerged materials is an extremely valuable source of information on the origin and precedence of the wrecks, and also the raw materials employed during the manufacturing of the objects found in these sites. Nevertheless, sometimes it is not possible to extract the archaeological material from the marine environment due to size of the sample, the legislation or preservation purposes. In these cases, the in-situ analysis turns into the only alternative for obtaining information. In spite of this demand, no analytical techniques are available for the in-situ chemical characterization of underwater materials. The versatility of laser-induced breakdown spectroscopy (LIBS) has been successfully tested in oceanography 1. Advantages such as rapid and in situ analysis with no sample preparation make LIBS a suitable alternative for field measurements. To further exploit the inherent advantages of the technology, a mobile fiber-based LIBS platform capable of performing remote measurements up to 50 meters range has been designed for the recognition and identification of artworks in underwater archaeological shipwrecks. The LIBS prototype featured both single-pulse (SP-LIBS) and multi-pulse excitation (MP-LIBS) 2. The use of multi-pulse excitation allowed an increased laser beam energy (up to 95 mJ) transmitted through the optical fiber. This excitation mode results in an improved performance of the equipment in terms of extended range of analysis (to a depth of 50 m) and a broader variety of samples to be analyzed (i.e., rocks, marble, ceramics and concrete). In the present work, the design and construction considerations of the instrument are reported and its performance is discussed on the basis of the spectral response, the remote irradiance achieved upon the range of analysis and its influence on plasma properties, as well as the effect of the laser pulse duration and purge gas to the LIBS signal. Also, to check the reliability and reproducibility of the instrument for field analysis several robustness tests were performed outside the lab. Finally, the capability of this instrument was successfully demonstrated in an underwater archaeological shipwreck (San Pedro de Alcántara, Malaga).

The influence of environmental distraction on cognitive abilities in ADL performance after frontal brain injured.

Background: Previous studies have reported errors in Activities of Daily Living (ADL) under the presence of distracting objects in dementia and brain injury patients. However, little is known about which distractor-target objects relation might be more harmful for performance. Method: We compared the ADL execution in frontal brain injured patients and control participants under two conditions: One in which target objects were mixed with distractor objects that constituted an alternative semantically related but non-required task (contextual condition) and another in which target objects were mixed with related but isolated distractors that did not constituted a coherent task (non-contextual condition). We separately analyzed ADL commission errors (repetitions, substitutions, objects manipulations, failures in sequence, extra actions) and omissions. In addition, the participants were evaluated with a neuropsychological protocol including a very specific executive functions task (Selective attention, Stimulus-Stimulus and Stimulus-Response conflict). Results: We found that frontal patients produced more commission errors compared to control participants, but only under the contextual condition. No between groups significant differences were found in omissions in both conditions or commission errors in non-contextual conditions. Scores in the Stimulus-Response conflict was significantly correlated with commission errors in the contextual condition. Conclusion: The presence of different non-target objects in ADL performance could require different cognitive process. Contextual ADL conditions required a higher level of executive functions, especially at the level of response (Stimulus-Response conflict). Application to Practice: Occupational therapists should control the presence of objects related to the target task according to the intervention objectives with the patients.

Probability and Common-Sense: Tandem Towards Robust Robotic Object Recognition in Ambient Assisted Living

The suitable operation of mobile robots when providing Ambient Assisted Living (AAL) services calls for robust object recognition capabilities. Probabilistic Graphical Models (PGMs) have become the de-facto choice in recognition systems aiming to e ciently exploit contextual relations among objects, also dealing with the uncertainty inherent to the robot workspace. However, these models can perform in an inco herent way when operating in a long-term fashion out of the laboratory, e.g. while recognizing objects in peculiar con gurations or belonging to new types. In this work we propose a recognition system that resorts to PGMs and common-sense knowledge, represented in the form of an ontology, to detect those inconsistencies and learn from them. The utilization of the ontology carries additional advantages, e.g. the possibility to verbalize the robot's knowledge. A primary demonstration of the system capabilities has been carried out with very promising results.