A robust extended H-infinity filtering approach to multi-robot cooperative localization in dynamic indoor environments

Multi-robot cooperative localization serves as an essential task for a team of mobile robots to work within an unknown environment. Based on the real-time laser scanning data interaction, a robust approach is proposed to obtain optimal multi-robot relative observations using the Metric-based Iterative Closest Point (MbICP) algorithm, which makes it possible to utilize the surrounding environment information directly instead of placing a localization-mark on the robots. To meet the demand of dealing with the inherent non-linearities existing in the multi-robot kinematic models and the relative observations, a robust extended H∞ filtering (REHF) approach is developed for the multi-robot cooperative localization system, which could handle non-Gaussian process and measurement noises with respect to robot navigation in unknown dynamic scenes. Compared with the conventional multi-robot localization system using extended Kalman filtering (EKF) approach, the proposed filtering algorithm is capable of providing superior performance in a dynamic indoor environment with outlier disturbances. Both numerical experiments and experiments conducted for the Pioneer3-DX robots show that the proposed localization scheme is effective in improving both the accuracy and reliability of the performance within a complex environment.This work was supported inpart by the National Natural Science Foundation of China under grants 61075094, 61035005 and 61134009

Do (and say) as I say: Linguistic adaptation in human-computer dialogs

© Theodora Koulouri, Stanislao Lauria, and Robert D. Macredie. This article has been made available through the Brunel Open Access Publishing Fund.There is strong research evidence showing that people naturally align to each other’s vocabulary, sentence structure, and acoustic features in dialog, yet little is known about how the alignment mechanism operates in the interaction between users and computer systems let alone how it may be exploited to improve the efficiency of the interaction. This article provides an account of lexical alignment in human–computer dialogs, based on empirical data collected in a simulated human–computer interaction scenario. The results indicate that alignment is present, resulting in the gradual reduction and stabilization of the vocabulary-in-use, and that it is also reciprocal. Further, the results suggest that when system and user errors occur, the development of alignment is temporarily disrupted and users tend to introduce novel words to the dialog. The results also indicate that alignment in human–computer interaction may have a strong strategic component and is used as a resource to compensate for less optimal (visually impoverished) interaction conditions. Moreover, lower alignment is associated with less successful interaction, as measured by user perceptions. The article distills the results of the study into design recommendations for human–computer dialog systems and uses them to outline a model of dialog management that supports and exploits alignment through mechanisms for in-use adaptation of the system’s grammar and lexicon

An optimally weighted user- and item-based collaborative filtering approach to predicting baseline data for Friedreich's Ataxia patients

Seventh Framework Programme of the European Union; Royal Society of the U.K., and the Alexander von Humboldt Foundation of Germany

The influence of visual feedback and gender dynamics on performance, perception and communication strategies in CSCW

The effects of gender in human communication and human-computer interaction are well-known, yet little is understood about how it influences performance in the complex, collaborative tasks in computer-mediated settings – referred to as Computer-Supported Collaborative Work (CSCW) – that are increasingly fundamental to the way in which people work. In such tasks, visual feedback about objects and events is particularly valuable because it facilitates joint reference and attention, and enables the monitoring of people’s actions and task progress. As such, software to support CSCW frequently provides shared visual workspace. While numerous studies describe and explain the impact of visual feedback in CSCW, research has not considered whether there are differences in how females and males use it, are aided by it, or are affected by its absence. To address these knowledge gaps, this study explores the effect of gender – and its interactions within pairs – in CSCW, with and without visual feedback. An experimental study is reported in which mixed-gender and same-gender pairs communicate to complete a collaborative navigation task, with one of the participants being under the impression that s/he is interacting with a robot (to avoid gender-related social preconceptions). The study analyses performance, perceptions and communication strategies. As predicted, there was a significant benefit associated with visual feedback in terms of language economy and efficiency. However, it was also found that visual feedback may be disruptive to task performance, because it relaxes the users’ precision criteria and inflates their assumptions of shared perspective. While no actual performance difference was found between males and females in the navigation task, females rated their own performance less positively than did males. In terms of communication strategies, males had a strong tendency to introduce novel vocabulary when communication problems occurred, while females exhibited more conservative behaviour. When visual feedback was removed, females adapted their strategies drastically and effectively, increasing the quality and specificity of the verbal interaction, repeating and re-using vocabulary, while the behaviour of males remained consistent. These results are used to produce design recommendations for CSCW systems that will suit users of both genders and enable effective collaboration

Teaching introductory programming: a quantitative evaluation of different approaches

© ACM, 2014. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM Transactions on Computing Education, 2014, Vol. 14, No. 4, Article 26, DOI: http://dx.doi.org/10.1145/266241

Weightless neural networks A study of grey level transformation aspects

Available from British Library Document Supply Centre- DSC:DXN060731 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Twitter Controls the Household Heating System

The home is composed of many different devices, services and related technologies. These have a lack of communication with one another. A challenge within domestic central heating system is being able to exploit the functionality and offer a common means of monitoring and controlling, either locally or remotely. This paper introduces a domestic central heating system design for householders to control it through twitter, either locally or remotely. We believe by enabling householders to monitor and control domestic central heating system could contribute to make a smart home