105 research outputs found

    Improved Use of Foot Force Sensors and Mobile Phone GPS for Mobility Activity Recognition

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    A Game-Theory Based Incentive Framework for an Intelligent Traffic System as Part of a Smart City Initiative

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    Intelligent Transportation Systems (ITSs) can be applied to inform and incentivize travellers to help them make cognizant choices concerning their trip routes and transport modality use for their daily travel whilst achieving more sustainable societal and transport authority goals. However, in practice, it is challenging for an ITS to enable incentive generation that is context-driven and personalized, whilst supporting multi-dimensional travel goals. This is because an ITS has to address the situation where different travellers have different travel preferences and constraints for route and modality, in the face of dynamically-varying traffic conditions. Furthermore, personalized incentive generation also needs to dynamically achieve different travel goals from multiple travellers, in the face of their conducts being a mix of both competitive and cooperative behaviours. To address this challenge, a Rule-based Incentive Framework (RIF) is proposed in this paper that utilizes both decision tree and evolutionary game theory to process travel information and intelligently generate personalized incentives for travellers. The travel information processed includes travellers’ mobile patterns, travellers’ modality preferences and route traffic volume information. A series of MATLAB simulations of RIF was undertaken to validate RIF to show that it is potentially an effective way to incentivize travellers to change travel routes and modalities as an essential smart city service

    Optimized Computation Combining Classification and Detection Networks with Distillation

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    A WiFi RSSI Ranking Fingerprint Positioning System and Its Application to Indoor Activities of Daily Living Recognition

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    WiFi RSSI (Received Signal Strength Indicators) seem to be the basis of the most widely used method for Indoor Positioning Systems (IPS) driven by the growth of deployed WiFi Access Points (AP), especially within urban areas. However, there are still several challenges to be tackled: its accuracy is often 2-3m, it’s prone to interference and attenuation effects, and the diversity of Radio Frequency (RF) receivers, e.g., smartphones, affects its accuracy. RSSI fingerprinting can be used to mitigate against interference and attenuation effects. In this paper, we present a novel, more accurate, RSSI ranking-based method that consists of three parts. First, an AP selection based on a Genetic Algorithm (GA) is applied to reduce the positioning computational cost and increase the positioning accuracy. Second, Kendall Tau Correlation Coefficient (KTCC) and a Convolutional Neural Network (CNN) are applied to extract the ranking features for estimating locations. Third, an Extended Kalman filter (EKF) is then used to smooth the estimated sequential locations before Multi-Dimensional Dynamic Time Warping (MD-DTW) is used to match similar trajectories or paths representing ADLs from different or the same users that vary in time and space In order to leverage and evaluate our IPS system, we also used it to recognise Activities of Daily Living (ADL) in an office like environment. It was able to achieve an average positioning accuracy of 1.42m and a 79.5% recognition accuracy for 9 location-driven activities

    A Provable Semi-Outsourcing Privacy Preserving Scheme for Data Transmission From IoT Devices

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    A semi-outsourcing privacy-preserving scheme is proposed in this paper for the IoT data collection named semi-outsourcing privacy-preserving (SOPP), which supports delegated identity authentication for the IoT devices without revealing the transmitted data. Compared with other schemes that implement the authentication based upon using trusted cloud services, the design of our scheme SOPP can achieve the delegated authentication on untrusted public clouds while providing privacy-preserving data transmission. Meanwhile, the implemented one-way authentication can reduce the communication cost for the IoT devices (especially for the low-resource ones) to prolong their battery life. The performance of the SOPP scheme is demonstrated for its use in the resource-constrained IoT devices and compared with a benchmark trusted cloud scheme including one based upon certificates and an interactive (two-way) authentication scheme

    An Adaptive Human Activity-Aided Hand-Held Smartphone-Based Pedestrian Dead Reckoning Positioning System

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    Pedestrian dead reckoning (PDR), enabled by smartphones’ embedded inertial sensors, is widely applied as a type of indoor positioning system (IPS). However, traditional PDR faces two challenges to improve its accuracy: lack of robustness for different PDR-related human activities and positioning error accumulation over elapsed time. To cope with these issues, we propose a novel adaptive human activity-aided PDR (HAA-PDR) IPS that consists of two main parts, human activity recognition (HAR) and PDR optimization. (1) For HAR, eight different locomotion-related activities are divided into two classes: steady-heading activities (ascending/descending stairs, stationary, normal walking, stationary stepping, and lateral walking) and non-steady-heading activities (door opening and turning). A hierarchical combination of a support vector machine (SVM) and decision tree (DT) is used to recognize steady-heading activities. An autoencoder-based deep neural network (DNN) and a heading range-based method to recognize door opening and turning, respectively. The overall HAR accuracy is over 98.44%. (2) For optimization methods, a process automatically sets the parameters of the PDR differently for different activities to enhance step counting and step length estimation. Furthermore, a method of trajectory optimization mitigates PDR error accumulation utilizing the non-steady-heading activities. We divided the trajectory into small segments and reconstructed it after targeted optimization of each segment. Our method does not use any a priori knowledge of the building layout, plan, or map. Finally, the mean positioning error of our HAA-PDR in a multilevel building is 1.79 m, which is a significant improvement in accuracy compared with a baseline state-of-the-art PDR system
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