Impact of agent reliability and predictability on trust in real time human-agent collaboration

Trust is a prerequisite for effective human-agent collaboration. While past work has studied how trust relates to an agent's reliability, it has been mainly carried out in turn based scenarios, rather than during real-time ones. Previous research identified the performance of an agent as a key factor influencing trust. In this work, we posit that an agent's predictability also plays an important role in the trust relationship, which may be observed based on users' interactions. We designed a 2x2 within-groups experiment with two baseline conditions: (1) no agent (users' individual performance), and (2) near-flawless agent (upper bound). Participants took part in an interactive aiming task where they had to collaborate with different agents that varied in terms of their predictability, and were controlled in terms of their performance. Our results show that agents whose behaviours are easier to predict have a more positive impact on task performance, reliance and trust while reducing cognitive workload. In addition, we modelled the human-agent trust relationship and demonstrated that it is possible to reliably predict users' trust ratings using real-time interaction data. This work seeks to pave the way for the development of trust-aware agents capable of adapting and responding more appropriately to users

Particle interactions in liquid magnetic colloids by zero field cooled measurements: effects on heating efficiency

The influence of magnetic interactions in assemblies formed by either aggregated or disaggregated uniform gamma-Fe_2O_3 particles are investigated as a function of particle size, concentration, and applied field. Hyperthermia and magnetization measurements are performed in the liquid phase of colloids consisting of 8 and 13 nm uniform gamma-Fe_2O_3 particles dispersed in water and hexane. Although hexane allows the disagglomerated obtaining particle system; aggregation is observed in the case of water colloids. The zero field cooled (ZFC) curves show a discontinuity in the magnetization values associated with the melting points of water and hexane. Additionally, for 13 nm gamma-Fe_2O_3 dispersed in hexane, a second magnetization jump is observed that depends on particle concentration and shifts toward lower temperature by increasing applied field. This second jump is related to the strength of the magnetic interactions as it is only present in disagglomerated particle systems with the largest size, i.e., is not observed for 8 nm superparamagnetic particles, and surface effects can be discarded. The specific absorption rate (SAR) decreases with increasing concentration only for the hexane colloid, whereas for aqueous colloids, the SAR is almost independent of particle concentration. Our results suggest that, as a consequence of the magnetic interactions, the dipolar field acting on large particles increases with concentration, leading to a decrease of the SAR

Improving magnetic properties of ultrasmall magnetic nanoparticles by biocompatible coatings

This paper deals with the effect of a biocompatible surface coating layer on the magnetic properties of ultrasmall iron oxide nanoparticles. Particles were synthesized by laser pyrolysis and fully oxidized to maghemite by acid treatment. The surface of the magnetic nanoparticles was systematically coated with either phosphonate (phosphonoacetic acid or pamidronic acid) or carboxylate-based (carboxymethyl dextran) molecules and the binding to the nanoparticle surface was analyzed. Magnetic properties at low temperature show a decrease in coercivity and an increase in magnetization after the coating process. Hysteresis loop displacement after field cooling is significantly reduced by the coating, in particular, for particles coated with pamidronic acid, which show a 10% reduction of the displacement of the loop. We conclude that the chemical coordination of carboxylates and phosphonates reduces the surface disorder and enhances the magnetic properties of ultrasmall maghemite nanoparticles.This work was partially supported by grants from the Spanish Ministry of Economy and Competitiveness (MAT2011-23641), the Madrid regional government (S009/MAT-1726 to MPM) and the 7th framework programme of the European Community (Nanomag 604448).Peer reviewe

Aireod

Purpose - To present a new special explosive ordnance disposal (EOD) robot designed to operate onboard airplanes. Design/methodology/approach - The design approach adopted is multidisciplinary: mechanical and control architectures are conceived simultaneously. Modularity and lifecycle are considered. Motion and EOD tasks are controlled in tele-operation. Findings - A new EOD robot was designed in detail and it is ready to be built. A dynamic simulator has been written and set-up, including a virtual reality module. The simulator is used to define the control logics. Simulation results are satisfactory. The simulator can be used as a training platform for the bomb squads. Research limitations/implications - The intent to keep the cost of the robot low conditioned the selection of the materials. Only aluminium and standard composites (like carbon fibers composites) have been used. A higher degree of freedom of the arm could increase the usability of the system; to limit the cost, the degree of freedom was limited to seven. A decision support system based on an expert system interfaced with the simulator could improve the performance of the system. Practical implications - A new EOD robot will be built and commercialised soon by the industrial partner Ansaldo Ricerche. Originality/value - The EOD robots available for use inside aircrafts are discussed. A new system named AirEOD is presented, including mobile platform, dexterous arm and all related design and control issues

AirEOD: a robot for on-board airplanes security

Terrorism is a very actual problem. Although terrorist attacks came in succession from the early seventies and eighties, recent events have raised the technological scale and the dimension of the actions. High level of security is required and bomb-disposal experts are frequently exposed to risks in mission. The effects on the society are blameworthy. Robotic systems can represent an effective mean to provide a high level of security without any risk for humans but several classes of applications exist for which no robot available on the market can be used. One of these application fields is the disposal of bombs inside airplanes. The paper describes the design and development of AirEOD, a mobile robot for rescue of a potential bomb in an airplane. The paper focuses on the mechatronic design of the robot and on its control system