ANGELAH: A Framework for Assisting Elders At Home

The ever growing percentage of elderly people within modern societies poses welfare systems under relevant stress. In fact, partial and progressive loss of motor, sensorial, and/or cognitive skills renders elders unable to live autonomously, eventually leading to their hospitalization. This results in both relevant emotional and economic costs. Ubiquitous computing technologies can offer interesting opportunities for in-house safety and autonomy. However, existing systems partially address in-house safety requirements and typically focus on only elder monitoring and emergency detection. The paper presents ANGELAH, a middleware-level solution integrating both ”elder monitoring and emergency detection” solutions and networking solutions. ANGELAH has two main features: i) it enables efficient integration between a variety of sensors and actuators deployed at home for emergency detection and ii) provides a solid framework for creating and managing rescue teams composed of individuals willing to promptly assist elders in case of emergency situations. A prototype of ANGELAH, designed for a case study for helping elders with vision impairments, is developed and interesting results are obtained from both computer simulations and a real-network testbed

A Novel Approach To Intelligent Navigation Of A Mobile Robot In A Dynamic And Cluttered Indoor Environment

The need and rationale for improved solutions to indoor robot navigation is increasingly driven by the influx of domestic and industrial mobile robots into the market. This research has developed and implemented a novel navigation technique for a mobile robot operating in a cluttered and dynamic indoor environment. It divides the indoor navigation problem into three distinct but interrelated parts, namely, localization, mapping and path planning. The localization part has been addressed using dead-reckoning (odometry). A least squares numerical approach has been used to calibrate the odometer parameters to minimize the effect of systematic errors on the performance, and an intermittent resetting technique, which employs RFID tags placed at known locations in the indoor environment in conjunction with door-markers, has been developed and implemented to mitigate the errors remaining after the calibration. A mapping technique that employs a laser measurement sensor as the main exteroceptive sensor has been developed and implemented for building a binary occupancy grid map of the environment. A-r-Star pathfinder, a new path planning algorithm that is capable of high performance both in cluttered and sparse environments, has been developed and implemented. Its properties, challenges, and solutions to those challenges have also been highlighted in this research. An incremental version of the A-r-Star has been developed to handle dynamic environments. Simulation experiments highlighting properties and performance of the individual components have been developed and executed using MATLAB. A prototype world has been built using the WebotsTM robotic prototyping and 3-D simulation software. An integrated version of the system comprising the localization, mapping and path planning techniques has been executed in this prototype workspace to produce validation results

Towards Parallel Educational Worlds

Proceedings of: 2011 IEEE Global Engineering Education Conference (EDUCON 2011): Learning Environments and Ecosystems in Engineering Education. Amman, Jordan, 4-6 April 2011.Augmented Reality, 3D virtual worlds, etc.: the technology has evolved tremendously and so has its application to the field of education. Digital technologies have advanced to the point, where we are reproducing digitally more and more aspects of our life. We have parallel worlds: on the one hand the real world, and on the other virtual worlds, that can in fact be linked to the real one. They have different properties, but they can enrich and complement each other. In this paper, we explore the possibilities and challenges of these parallel worlds for educational uses.The eMadrid Excellence Network is being funded by the Madrid Regional Government (Comunidad de Madrid) with grant No. S2009/TIC-165. We wish to acknowledge stimulating discussions with our partners in the context of the network. Partial support has also been received from the Learn3 project (TIN2008-05163) and the SOLITE project (CYTED 508AC0341).Publicad

Cancellation Techniques for Co-channel Interference in MIMO-OFDM Systems and Evaluating Their Performance

In a wireless communication system, the transmitted signal is exposed to various surfaces where it bounces and results in several delayed versions of the same signal at the receiver end. The delayed signals are in the form of electromagnetic waves that are diffracted and reflected from the various object surfaces. These result in co-channel interferences for wireless systems. MIMO has proven to be a striking solution for the new generation of wireless systems. MIMO-OFDM system with QPSK modulation is considered as the wireless system for studying the performance of interference cancellation techniques. The BER performance is studied in channels such as Rayleigh and Rician Fading Channels. The effects of interference are reduced to a certain extent by the inclusion of CDMA (spread spectrum technique) as Technique 1. The effects of interference on this system have been further reduced using the LMS filter as Technique 2. Hence, to show better performance in MIMO-OFDM systems, it is recommended to employ both CDMA and LMS filters to decrease the effects of co-channel interference. It is observed that the parameter BER reduces as the SNR increases for both these channels. Doi: 10.28991/esj-2021-01313 Full Text: PD

Antena inteligente para aplicações RFID

Mestrado em Engenharia Electrónica e TelecomunicaçõesThe adoption and proliferation of information systems in many business and personal activities leads to the need of tagging and tracking items and services. Radio frequency identi cation (RFID) systems were developed as an e ort to answer the increasing needs of particulars and enterprises alike for wireless identi cation of objects and data exchange services, enabling a large number of businesses to reduce costs and increase revenue. As to further develop the e ciency provided by businesses worldwide, smart antenna systems were introduced as core component in their production and service providing lines, opening the path for innovative and robust wireless RFID based communication schemes, providing advanced signal capturing, processing characteristics and enhanced tracking and process automation. Smart antennas can be installed within RFID readers, enabling them to more e ciently process returned echoes by the tags and therefore improving the identi cation mechanism. RFID reader architectures with an embedded smart antenna network reliably improve the throughput, the reading speed and position detection of tagged items. A smart antenna based circuit is proposed here for RFID assisted localization and for beam steering applications using a uniform linear array of microstrip directional antennas. Several beamforming and direction of arrival estimation methods were employed in order to analyze their performance and resolution based on the computational load, modulation, and the overall environment in which the smart anetnna system may be deployed.A adoção e proliferação de sistemas de informação em várias indústrias e atividades pessoais são responsáveis pela crescente necessidade de identifcar e rastrear itens e serviços. Sistemas de identificação por rádiofrequência (RFID) foram desenvolvidos de modo a responder às crescentes necessidades tanto de particulares como de empresas quanto à utilização de sistemas de identificaçao e de transmissão de dados sem _os, permitindo a redução de despesas e o aumento de receitas a várias empresas. De modo a melhorar a eficiência de empresas a uma escala global, sistemas de antenas inteligentes foram introduzidos nas suas linhas de manufatura e de prestação de serviços como um componente central, abrirando o caminho para esquemas de comunicação sem _os inovadores e robustos, baseados em RFID, facultando processos de captura e processamento de sinal avançados capazes de fornecer melhorias em aplicações de rastreamento e automação de processos. Antenas inteligentes podem ser instaladas em leitores RFID, permitindo um melhor processamento de sinais transmitidos pelas etiquetas, dando origem a um método de identificação mais eficiente. A arquitectura de leitores RFID com uma rede de antenas inteligentes embutida garante melhorias na taxa de transferência e na rapidez de leitura de informação assim como na deteção de itens etiquetados. Um circuito baseado em sistemas de antenas inteligentes é proposto neste trabalho para localização assistida dispositivos RFID e para direccionamento de feixe através da utilizaçao de um agregado linear e uniforme de antenas microstrip diretivas. Várias técnicas de direcionamento de feixe e de estimativa de angulo de chegada foram utilizados, de modo a analisar o desempenho e a resolução de cada algoritmo de acordo com a carga computacional, modulação utilizada e o ambiente em que o sistema de antenas inteligentes poderá ser implementado

Recent development in multimedia e-learning technologies

Multimedia and networking technologies have significantly impacted on our daily activities, particularly in terms of how we learn. Nowadays, classroom teaching no longer simply relies on chalk and blackboard as the prime medium for course dissemination. E-learning technologies have made it possible to provide a virtual classroom environment on the Web through supporting teacher-student and student-student communications, course material distribution as well as online student assessments. They provide students with more control over their learning schedule and pace. On top of this, multimedia technologies further offer students different forms of media to match their learning styles, leading to enhancements of their learning effectiveness. This extended introduction discusses the latest e-learning specific multimedia technologies, their research challenges and future trends from both pedagogical and technological perspectives. We also summarize the papers included in this special issue

All Source Sensor Integration Using an Extended Kalman Filter

The global positioning system (GPS) has become an ubiquitous source for navigation in the modern age, especially since the removal of selective availability at the beginning of this century. The utility of the GPS is unmatched, however GPS is not available in all environments. Heavy reliance on GPS for navigation makes the warfighter increasingly vulnerability as modern warfare continues to evolve. This research provides a method for incorporating measurements from a massive variety of sensors to mitigate GPS dependence. The result is the integration of sensor sets that encompass those examined in recent literature as well as some custom navigation devices. A full-state extended Kalman filter is developed and implemented, accommodating the requirements of the varied sensor sets and scenarios. Some 19 types of sensors are used in multiple quantities including inertial measurement units, single cameras and stereo pairs, 2D and 3D laser scanners, altimeters, 3-axis magnetometers, heading sensors, inclinometers, a stop sign sensor, an odometer, a step sensor, a ranging device, a signal of opportunity sensor, global navigation satellite system sensors, an air data computer, and radio frequency identification devices. Simulation data for all sensors was generated to test filter performance. Additionally, real data was collected and processed from an aircraft, ground vehicles, and a pedestrian. Measurement equations are developed to relate sensor measurements to the navigation states. Each sensor measurement is incorporated into the filter using the Kalman filter measurement update equations. Measurement types are segregated based on whether they observe instantaneous or accumulated state information. Accumulated state measurements are incorporated using delayed-state update equations. All other measurements are incorporated using the numerically robust UD update equations

Barometer-Assisted 3D Indoor WiFi Localization for Smart Devices-Map Selection and Performance Evaluation

Recently, indoor localization becomes a hot topic no matter in industry or academic field. Smart phones are good candidates for localization since they are carrying various sensors such as GPS, Wi-Fi, accelerometer, barometer and etc, which can be used to estimate the current location. But there are still many challenges for 3D indoor geolocation using smart phones, among which the map selection and 3D performance evaluation problems are the most common and crucial. In the indoor environment, the popular outdoor Google maps cannot be utilized since we need maps showing the layout of every individual floor. Also, layout of different floors differ from one another. Therefore, algorithms are required to detect whether we are inside or outside a building and determine on which floor we are located so that an appropriate map can be selected accordingly. For Wi-Fi based indoor localization, the performance of location estimation is closely related to the algorithms and deployment that we are using. It is difficult to find out a general approach that can be used to evaluate any localization system. On one hand, since the RF signal will suffer extra loss when traveling through the ceilings between floors, its propagation property will be different from the empirical ones and consequently we should design a new propagation model for 3D scenarios. On the other hand, properties of sensors are unique so that corresponding models are required before we analyze the localization scheme. In-depth investigation on the possible hybrid are also needed in case more than one sensor is operated in the localization system. In this thesis, we firstly designed two algorithms to use GPS signal for detecting whether the smart device is operating inside or outside a building, which is called outdoor-indoor transition detection. We also design another algorithm to use barometer data for determining on which floor are we located, which is considered as a multi-floor transition detection. With three scenarios designed inside the Akwater Kent Laboratory building (AK building) at Worcester Polytechnic Institute (WPI), we collected raw data from an Android phone with a version of 4.3 and conducted experimental analysis based on that. An efficient way to quantitatively evaluate the 3D localization systems is using Cramer-Rao Lower Bound (CRLB), which is considered as the lower bound of the estimated error for any localization system. The characteristics of Wi-Fi and barometer signals are explored and proper models are introduced as a foundation. Then we extended the 2D CRLB into a 3D format so that it can fit the our 3D scenarios. A barometer-assisted CRLB is introduced as an improvement for the existing Wi-Fi Receive Signal Strength (RSS)-only scheme and both of the two schemes are compared with the contours in every scenario and the statistical analysis