Recent statistics on causes of aviation accidents and incidents demonstrate that to increase air-transportation safety, we must reduce human errors' impact on operations. So, the industry should first address human factors related to people in stressful roles to significantly minimize such errors. In particular, aviation maintenance employees work under high-pressure conditions- that is, they're under strict time constraints and must adhere to stringent guidelines. Because of such constraints, they might be prone to making errors. Unfortunately, many of these errors might not become apparent until an accident occurs. Although maintenance errors are a recognized threat to aviation safety, there are few simulation and computer-based tools for managing human factor issues in this field. The main advantages in using computer-based systems to train or support technicians are that computers don't forget and that they can help humans clearly understand facts. Such features can help reduce errors due to procedure violations, misinterpretation of facts, or insufficient training. Toward that end, augmented reality (AR) is a promising technology to build advanced interfaces using interactive and wearable visualization systems to implement new methods to display documentation as digital data and graphical databases. Nevertheless, many factors-such as cumbersome hardware, the need to put markers on the aircraft, and the need to quickly create digital content-seem to hinder its effective implementation in industry.

Variations in alpha rhythm have a significant role in perception and attention. Recently, alpha decrease has been associated with externally directed attention, especially in the visual domain, whereas alpha increase has been related to internal processing such as mental arithmetic. However, the role of alpha oscillations and how the different components of a task (processing of external stimuli, internal manipulation/representation, and task demand) interact to affect alpha power are still unclear. Here, we investigate how alpha power is differently modulated by attentional tasks depending both on task difficulty (less/more demanding task) and direction of attention (internal/external). To this aim, we designed two experiments that differently manipulated these aspects. Experiment 1, outside Virtual Reality (VR), involved two tasks both requiring internal and external attentional components (intake of visual items for their internal manipulation) but with different internal task demands (arithmetic vs. reading). Experiment 2 took advantage of the VR (mimicking an aircraft cabin interior) to manipulate attention direction: it included a condition of VR immersion only, characterized by visual external attention, and a condition of a purely mental arithmetic task during VR immersion, requiring neglect of sensory stimuli. Results show that: (1) In line with previous studies, visual external attention caused a significant alpha decrease, especially in parieto-occipital regions; (2) Alpha decrease was significantly larger during the more demanding arithmetic task, when the task was driven by external visual stimuli; (3) Alpha dramatically increased during the purely mental task in VR immersion, whereby the external stimuli had no relation with the task. Our results suggest that alpha power is crucial to isolate a subject from the environment, and move attention from external to internal cues. Moreover, they emphasize that the emerging use of VR associated with EEG may have important implications to study brain rhythms and support the design of artificial systems.

Purpose – The purpose of this paper is to describe the method of virtually and physically reconstructing the missing part of a badly damaged medieval skull by means of reverse engineering, computer-aided design (CAD) and rapid prototyping (RP) techniques. Design/methodology/approach – Laser scanning data were used to create the 3D model of the damaged skull. Starting from this digital model, a virtual reconstruction of the missing part of the skull, based on the ideal symmetry with respect to the mid-sagittal plane, was achieved in a CAD environment. Finally, the custom-designed model was directly fabricated by means of the RP process. Findings – The result shows that the designed missing part of the skull fits very well with the existing skeletal remains. The final physical assembly of the prototyped element on the damaged skull was tested, restoring it to its whole original shape. Research limitations/implications – The entire process was time-consuming and may be applied just to the most representative skeletal remains. Practical implications – The method allows accurate fabrication of the missing part of the skull to be joined with the original skeletal remains. The advantage of using this technique is that the joining operation can be carried out without any need of supplementary connecting material, such as glue or plaster, to fix together the two parts. Originality/value – The reversible and non-invasive method improves the restoration process, reduces the risk of damage to the skeletal structure and allows reversion to the original repair as it was before.