Quantum circuits performing arithmetic operations are critical in quantum computing because of the need for such operations in proven quantum algorithms. Although quantum computers are becoming increasingly resourceful, the number of qubits currently available is still limited. Furthermore, these qubits are heavily affected by internal and external noise. It has been proven that quantum circuits built using Clifford $+T$ gates can be made fault tolerant. However, the use of the $T$ gates comes at a very high cost. If the number of $T$ gates used in a circuit is not optimized, the cost of the circuit will be increased excessively. As a consequence, it is essential to optimize the circuits so that they are as resource efficient as possible and also noise tolerant. This paper presents the design of a circuit to perform the multiplication of two integers. The circuit is built using only Clifford $+T$ gates for compatibility with error detection and correction codes. It outperforms the circuits in the state of the art in terms of $T$ count and $T$ depth.

Activity Recognition (AR) is an active research topic focused on detecting human actions and behaviours in smart environments. In this work, we present the on-line activity recognition platform DOLARS (Distributed On-line Activity Recognition System) where data from heterogeneous sensors are evaluated in real time, including binary, wearable and location sensors. Different descriptors and metrics from the heterogeneous sensor data are integrated in a common feature vector whose extraction is developed by a sliding window approach under real-time conditions. DOLARS provides a distributed architecture where: (i) stages for processing data in AR are deployed in distributed nodes, (ii) temporal cache modules compute metrics which aggregate sensor data for computing feature vectors in an efficient way; (iii) publish-subscribe models are integrated both to spread data from sensors and orchestrate the nodes (communication and replication) for computing AR and (iv) machine learning algorithms are used to classify and recognize the activities. A successful case study of daily activities recognition developed in the Smart Lab of The University of Almería (UAL) is presented in this paper. Results present an encouraging performance in recognition of sequences of activities and show the need for distributed architectures to achieve real time recognition.

Nowadays, Smart Environments (SEs) enable the monitoring of people with physical disabilities by incorporating activity recognition. Thermal cameras are being incorporated as they preserve privacy. Some Deep Learning (DL) solutions use the pose of the users because it removes external noise. Although there are robust DL solutions in the visible spectrum, they fail in the thermal domain. Thus, we propose THPoseLite (Thermal Human Pose Lite), a Convolutional Neural Network (CNN) based on MobileNetV2 that extracts pose from Thermal Images (TIs). In a novel way, an auto-labeling approach has been developed. It includes a background removal using an optical flow estimator. It also integrates Blazepose (a pose estimator for Visible spectrum images (VSIs)) to obtain the poses in the pre-processed TIs. Results show that the pre-processing increases the percentage of detected poses by Blazepose from 19.55% to 76.85%. This allows the recording of Human Pose Estimation (HPE) datasets in the visible spectrum without requiring visible spectrum cameras or manually annotating datasets. Furthermore, THPoseLite has been embedded in an Internet of Things (IoT) device incorporating an edge Tensor Processing Unit (TPU) accelerator, which can process TIs recorded at 9 Frames Per Second (FPS) in real-time (12.28 FPS). It requires fewer than 6W of energy to run. It has been achieved using model quantization, decreasing the accuracy in estimating the poses by only 1%. The MSE of MobileNetV2 in test images is 35.48, obtaining accurate poses in 21% of the images that Blazepose is not able to detect any pose.