Semantic-based decision support for remote care of dementia patients

This paper investigates the challenges in developing a semantic-based Dementia Care Decision Support System based on the non-intrusive monitoring of the patient's behaviour. Semantic-based approaches are well suited for modelling context-aware scenarios similar to Dementia care systems, where the patient's dynamic behaviour observations (occupants movement, equipment use) need to be analysed against the semantic knowledge about the patient's condition (illness history, medical advice, known symptoms) in an integrated knowledgebase. However, our research findings establish that the ability of semantic technologies to reason upon the complex interrelated events emanating from the behaviour monitoring sensors to infer knowledge assisting medical advice represents a major challenge. We attempt to address this problem by introducing a new approach that relies on propositional calculus modelling to segregate complex events that are amenable for semantic reasoning from events that require pre-processing outside the semantic engine before they can be reasoned upon. The event pre-processing activity also controls the timing of triggering the reasoning process in order to further improve the efficiency of the inference process. Using regression analysis, we evaluate the response-time as the number of monitored patients increases and conclude that the incurred overhead on the response time of the prototype decision support systems remains tolerable

Echo state network for occupancy prediction and pattern mining in intelligent environment

Pattern analysis and prediction of sensory data is becoming an increasing scientific challenge and a massive economical interest supports the need for better pattern mining techniques. The aim of this paper is to investigate efficient mining of useful information from a sensor network representing an ambient intelligence environment. The goal is to extract and predict behavioral patterns of a person in his/her daily activities by analyzing the time series data representing the behaviour of the occupant, generated using occupancy sensors. There are various techniques available for analysis and prediction of a continuous time series signal. However, the occupancy signal is represented by a binary time series where only discrete values of a signal are available. To build the prediction model, recurrent neural networks are investigated. They are proven to be useful tools to solve the difficulties of the temporal relationships of inputs between observations at different time steps, by maintaining internal states that have memory. In this paper, a special form of recurrent neural network, the so-called Echo State Network (ESN) is used in which discrete values of time series can be well processed. Then, a model developed based on ESN is compared with the most popular recurrent neural net-works; namely Back Propagation Through Time (BPTT) and Real Time Recurrent Learning (RTRL). The results showed that ESN provides better prediction results compared with BPTT and RTRL. Using ESN, large datasets are learnt in only few minutes or even seconds. It can be concluded that ESN are efficient and valuable tools in binary time series prediction. The results presented in this paper are based on simulated data generated from a simulator representing a person in a 1 bedroom flat

The Design of a 360°-Switched-Beam-Base Station Antenna

The concept of switched-beam antenna (SBA) systems covering an area of 360° for wireless base station applications is presented. First, a reconfigurable pattern antenna (RPA), which is composed of an omnidirectional slot-antenna array surrounded by an active cylindrical frequency selective surface (FSS), is studied. The behavior of FSS is controlled by PIN diodes which are able to divide the Azimuth plane into six sectors from one common source. Unfortunately for a sector antenna, a huge number of diodes are required which complicates the structure in terms of efficiency and complexity. However, a simple and an efficient SBA configuration based on a hexagonal Fabry-Pérot cavity leaky wave antenna (FPC LWA) arrays is proposed as a solution for RPA problems. A sector-directive beam is generated from a simple patch antenna embedded inside a resonant Fabry-Pérot cavity with specific dimensions which have an influence on beamwidth and radiation efficiency. To increase more sectorization level and channel’s capacity, the proposed sector in FPC LWA arrays can be divided into three subsectors by using an active high-impedance surface (HIS). As a conclusion, SBA based on FPC LWA is the most suitable solution for future wireless communications

Dual-band Textile AMC Antenna for WLAN/WBAN Applications on the Human Arm

This article presents a low-profile and flexible dual-band AMC Antenna operating at 2.45/ 5.8 GHz for wireless local area network (WLAN) applications. The antenna and the AMC were designed, simulated, and manufactured using textile materials for wearable applications functional at Wi-Fi bands. The functioning of this antenna under various bending conditions (in E and H-planes) around the human arm of various radii was examined and compared. A dual-band artificial magnetic conductor (AMC) structure on a textile substrate and dual hexagonal shape was used as a high impedance surface to reduce back radiation and specific absorption rate (SAR) and improve the gain and efficiency of the antenna. The overall comparison of the different used parameters shows a good agreement between the simulated and measured antenna performance in terms of bandwidth, gain, directivity and efficiency, and reveals that our antenna achieved the best results, making it a good candidate for WLAN applications. A study of the antenna/body interaction, based first on comparing the operation of the antenna with and without AMC in free space, and then on examining and analyzing the performance of the antenna in the vicinity of the human arm in different meteorological conditions, was carried out to demonstrate the effects of the skin on the dielectric properties of tissues. Measurements SAR of the antenna and the antenna assembly with AMC were performed and the final results show that the AMC surface isolated much of the back radiation emitted by the antenna to the human body. Also, acceptable SAR values were obtained, revealing that the body is well immune from the antenna radiation for the specific absorption rate which should meet. The simulation and measurement results demonstrate that electromagnetic communication on wet skin is viable with a decrease of antenna adapter efficiency and an increase in the SAR value, compared to that on dry skin. Antennas in the human body were simulated and analyzed in CST Microwave Studio (CST MWS)

Limitation of a Five-Port Reflectometer using planar elliptic couplers for UWB applications

In this paper, we present the design of ultra wideband (UWB) planar Five-Port Reflectometer using the elliptic coupler which has the advantage to offer a wide bandwidth compared to the hybrid one. The elliptic coupler and the five-port circuit were designed and simulated in the 1.5 to 3.5 GHz band using ADS software of Agilent. An analytical calculus and simulation results of a five-port circuit using elliptic coupler demonstrate limitations of this structure

Effects of tranexamic acid on death, disability, vascular occlusive events and other morbidities in patients with acute traumatic brain injury (CRASH-3): a randomised, placebo-controlled trial

Background Tranexamic acid reduces surgical bleeding and decreases mortality in patients with traumatic extracranial bleeding. Intracranial bleeding is common after traumatic brain injury (TBI) and can cause brain herniation and death. We aimed to assess the effects of tranexamic acid in patients with TBI. Methods This randomised, placebo-controlled trial was done in 175 hospitals in 29 countries. Adults with TBI who were within 3 h of injury, had a Glasgow Coma Scale (GCS) score of 12 or lower or any intracranial bleeding on CT scan, and no major extracranial bleeding were eligible. The time window for eligibility was originally 8 h but in 2016 the protocol was changed to limit recruitment to patients within 3 h of injury. This change was made blind to the trial data, in response to external evidence suggesting that delayed treatment is unlikely to be effective. We randomly assigned (1:1) patients to receive tranexamic acid (loading dose 1 g over 10 min then infusion of 1 g over 8 h) or matching placebo. Patients were assigned by selecting a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was head injury-related death in hospital within 28 days of injury in patients treated within 3 h of injury. We prespecified a sensitivity analysis that excluded patients with a GCS score of 3 and those with bilateral unreactive pupils at baseline. All analyses were done by intention to treat. This trial was registered with ISRCTN (ISRCTN15088122), ClinicalTrials.gov (NCT01402882), EudraCT (2011-003669-14), and the Pan African Clinical Trial Registry (PACTR20121000441277). Results Between July 20, 2012, and Jan 31, 2019, we randomly allocated 12 737 patients with TBI to receive tranexamic acid (6406 [50·3%] or placebo [6331 [49·7%], of whom 9202 (72·2%) patients were treated within 3 h of injury. Among patients treated within 3 h of injury, the risk of head injury-related death was 18·5% in the tranexamic acid group versus 19·8% in the placebo group (855 vs 892 events; risk ratio [RR] 0·94 [95% CI 0·86-1·02]). In the prespecified sensitivity analysis that excluded patients with a GCS score of 3 or bilateral unreactive pupils at baseline, the risk of head injury-related death was 12·5% in the tranexamic acid group versus 14·0% in the placebo group (485 vs 525 events; RR 0·89 [95% CI 0·80-1·00]). The risk of head injury-related death reduced with tranexamic acid in patients with mild-to-moderate head injury (RR 0·78 [95% CI 0·64-0·95]) but not in patients with severe head injury (0·99 [95% CI 0·91-1·07]; p value for heterogeneity 0·030). Early treatment was more effective than was later treatment in patients with mild and moderate head injury (p=0·005) but time to treatment had no obvious effect in patients with severe head injury (p=0·73). The risk of vascular occlusive events was similar in the tranexamic acid and placebo groups (RR 0·98 (0·74-1·28). The risk of seizures was also similar between groups (1·09 [95% CI 0·90-1·33]). Interpretation Our results show that tranexamic acid is safe in patients with TBI and that treatment within 3 h of injury reduces head injury-related death. Patients should be treated as soon as possible after injury. Funding National Institute for Health Research Health Technology Assessment, JP Moulton Charitable Trust, Department of Health and Social Care, Department for International Development, Global Challenges Research Fund, Medical Research Council, and Wellcome Trust (Joint Global Health Trials scheme)

Perception et description du contexte local appliquees a la commande d'un robot sous-marin

CNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Vers une lex mediterranea de l'arbitrage: Pour un cadre commun de référence

International audienc

Dual-band Textile AMC Antenna for WLAN/WBAN Applications on the Human Arm

This article presents a low-profile and flexible dual-band AMC Antenna operating at 2.45/ 5.8 GHz for wireless local area network (WLAN) applications. The antenna and the AMC were designed, simulated, and manufactured using textile materials for wearable applications functional at Wi-Fi bands. The functioning of this antenna under various bending conditions (in E and H-planes) around the human arm of various radii was examined and compared. A dual-band artificial magnetic conductor (AMC) structure on a textile substrate and dual hexagonal shape was used as a high impedance surface to reduce back radiation and specific absorption rate (SAR) and improve the gain and efficiency of the antenna. The overall comparison of the different used parameters shows a good agreement between the simulated and measured antenna performance in terms of bandwidth, gain, directivity and efficiency, and reveals that our antenna achieved the best results, making it a good candidate for WLAN applications. A study of the antenna/body interaction, based first on comparing the operation of the antenna with and without AMC in free space, and then on examining and analyzing the performance of the antenna in the vicinity of the human arm in different meteorological conditions, was carried out to demonstrate the effects of the skin on the dielectric properties of tissues. Measurements SAR of the antenna and the antenna assembly with AMC were performed and the final results show that the AMC surface isolated much of the back radiation emitted by the antenna to the human body. Also, acceptable SAR values were obtained, revealing that the body is well immune from the antenna radiation for the specific absorption rate which should meet. The simulation and measurement results demonstrate that electromagnetic communication on wet skin is viable with a decrease of antenna adapter efficiency and an increase in the SAR value, compared to that on dry skin. Antennas in the human body were simulated and analyzed in CST Microwave Studio (CST MWS)