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With semiautonomous vehicles and innovative assistance systems flooding the market, the characteristics of warning signals for automotive human–machine interfaces determine their effectiveness and usage. Within the context of advanced driver assistance systems, poorly designed warning signals have the potential to startle and distract drivers. Previous studies have investigated the effectiveness of multimodal warning signals and found that such signals reduce braking times. They are also associated with high levels of perceived urgency. This study aimed to investigate the effects of auditory, vibrotactile, and multimodal warning signals on perceived urgency, annoyance, and acceptability while varying the level of participants’ mental workload and the characteristics of the warning signals (interpulse interval). Results show that, compared with other signal modalities, multimodal warning signals appear to be effective in low-workload conditions but such effect disappears as the overall level of workload increases. These results are useful for the development of an adaptive warning signal system.

Objective: The aim of this study was to compare the pull-out bond strength of prefabricated titanium posts cemented with novel fast-setting calcium silicate, zinc phosphate, or glass ionomer cements. Methods: Sixty extracted human maxillary incisors were selected and received root canal treatment. Post space was prepared for titanium ParaPost XP size 5 (diameter=1.25 mm). The posts were cemented using novel calcium silicate cement, zinc phosphate cement, or glass ionomer cement (n=20). Specimens were stored in phosphate-buffered saline for 4 weeks. Subsequently, the posts were subjected to axial tensile force until bond failure. Data were analyzed by one-way ANOVA followed by multiple comparisons. Results: The posts cemented with novel calcium silicate cement (10.5±3.8 MPa) demonstrated significantly higher bond strength than zinc phosphate (8.0±2.6 MPa) and glass ionomer cements (8.0±2.7 MPa) (P<0.05). Conclusion: Within the limitation of the study, the pull-out bond strength of titanium post cemented with novel calcium silicate cement in endodontically treated teeth was superior to zinc phosphate and glass ionomer cements.

SUMMARYTo achieve a global cellular network, integration among segments offering different coverage (indoor, outdoor and global) must be pursued. Of course, the possibility to hold the call switching among different segments must be guaranteed. Hence, efficient algorithms to perform intersegment handover (ISHO) must be implemented.The paper aims at analysing some ISHO procedures developed in the frame of some European projects and other proposed in the literature, in a scenario with satellite and terrestrial segments interworking to achieve a worldwide cellular coverage.Performance evaluation will be carried out for different system configurations utilizing a dynamic satellite constellation simulator in the time domain. The impact of the distance user-gateway on performance will be addressed. For each procedure, the execution delay and its complementary cumulative distribution have been evaluated for different constellation geometries at different distances from the gateway.

To achieve really integrated systems allowing services and coverage provision @om both terrestrial and satellite segments the identification of suitable Intersegment Handover (ISHO) procedure represents one of the most critical and crucial issues. The paper aims at analyzing some ISHO procedures and to evaluate their performance for dzflerent system confgurations utilizing a dynamic constellation simulator in the time domain. On the basis of the above procedures, aiming at optimizing resources, a new procedure will be proposed and analyzed. For each procedure execution delay and the delay complementary cumulative distribution have been evaluated for different constellation geometry.Finally, a performance comparison among the various procedures will be presented

Satellite system architectures based on geostationary or Low Earth Orbit (LEO)/Medium Earth Orbit (MEO) constellation suffer from their intrinsic limitations in terms of coverage or flexibility. Traffic requirements concerning broadband services are expected to be very uneven both in time and space. To match this requirement and to improve coverage an innovative satellite system architecture, composed of a LEO/MEO segment to complement a Geostationary Earth Orbit (GEO) segment, has been proposed. In this scenario, to achieve interworking and to make it possible to hold the call while switching between the two segments, efficient intersegment handover (ISHO) procedures must be identified.The paper, after introducing the classical ISHO schemes, aims at defining and analysing an ISHO procedure developed to perform handover in case of hybrid constellations based on the use of both GEO and LEO/MEO orbits. Performance evaluation will be carried out for different system configurations utilizing a dynamic satellite constellation simulator in the time domain. The execution delay and its complementary cumulative distribution have been evaluated for different constellation geometry at different distances from the gateway. Copyright © 2002 John Wiley & Sons, Ltd.