Mobile Systems

... The different modules share an identical underlying structure, which is illus-trated in Figure 6 ... infrared sensors and by a sensor-fusion for real-time obstacle avoidance and backtracing. ... is adaptable to meet the different users' abilities) provides an uniform control for wheelchair ...

When the mechanisms of fading channels were first modeled in the 1950s and 1960s, the ideas were primarily applied to over-the-horizon communications covering a wide range of frequency bands. The 3-30 MHz high-frequency (HF) band is used for ionospheric communications, and the 300 MHz-3 GHz ultra-high-frequency (UHF) and 3-30 GHz super-high-frequency (SHF) bands are used for tropospheric scatter. Although the fading effects in a mobile radio system are somewhat different than those in ionospheric and tropospheric channels, the early models are still quite useful to help characterize fading effects in mobile digital communication systems. This tutorial addresses Rayleigh fading primarily in the UHF band. That affects mobile systems such as cellular and personal communication systems (PCS). Part I of the tutorial itemizes the fundamental fading manifestations and types of degradation

This paper presents design and implementation of a mobile embedded system to monitor and record key operation indicators of a distribution transformer like load currents, transformer oil and ambient temperatures. The proposed on-line monitoring system ...

Smart antennas enable space division multiple access, that is they manage access to a network by accounting for where users are spatially and using antenna technology to better isolate signals from noise and interference. For mobile systems, the benefits are increased capacity from existing cell sites, maximum return on infrastructure investment, and improved network efficiency and performance. In mobile systems, all the benefits for base-to-mobile and mobile-to-base paths occur as a result of smart antennas being installed at the base site. For fixed wireless systems, smart antennas are practical for both the base station and the remote station (RS). This paper discusses the increase in throughput that is realized by using smart antenna technology in a fixed wireless system. The management of packet transmission and reception, a key component of maximizing capacity, is described. Also included is a discussion of the user benefits and capacity impact of smart antennas at a remote station.

South America appears as a paradox for building the images of the New World's human colonization. It is a paradox, because according to the models of the Peopling of America, it was the last part of the continent to be occupied by humans, but in spite of that sites as old as or older than the “Clovis” sites from North America, started to be discovered since the last century. It is a laboratory, because the amount of the Pleistocene archaeological sites is as great as their variability. In this way, since the last two decades, the hemi-continent is placed in a privileged situation for questioning and reconstructing theories concerning the first Americans, and also for answering questions as when did they arrive, how did they arrive, what strategies (social, ecological and economic) did they develop for the colonization of such different environments, which were their ideas for achieving this colonization, and how does their use of space and resources reflect in the archaeological record. The model “Clovis the first”, brings an image of unidirectional migration of the first people, from the great North American plains to southern Patagonia. For a decade, this model showed itself insufficient for explaining the great archaeological variability of America and especially for referring those South American contexts directly to a Clovis migration. The new findings in South America are creating more anomalies for this model, which predicts that the arrival of Pleistocene hunter–gatherers should be around 10,000 years in Patagonia. The object of this paper is to discuss these models in view of South American archaeological evidence, and thus propose answers for removing the paradox. The axes which are considered are: the geographical and chronological distribution of the main localities of Patagonia and South America; the function of the sites within regional mobility systems; the use of subsistence resources; the differences in the circulation of lithic raw materials; and the different taphonomical histories. These characteristics will be compared with models of social network among mobile peoples and American paleolandscapes at the Pleistocene/Holocene transition and a new alternative route of peopling in South America will be presented. In this sense, the data of Patagonia are highly relevant.

This paper surveys the current state-of-the-art of technology, systems and applications in Augmented Reality. It describes work performed by many different research groups, the purpose behind each new Augmented Reality system, and the difficulties and problems encountered when building some Augmented Reality applications. It surveys mobile augmented reality systems challenges and requirements for successful mobile systems. This paper summarizes the current applications of Augmented Reality and speculates on future applications and where current research will lead Augmented Reality’s development. Challenges augmented reality is facing in each of these applications to go from the laboratories to the industry, as well as the future challenges we can forecast are also discussed in this paper. Section 1 gives an introduction to what Augmented Reality is and the motivations for developing this technology. Section 2 discusses Augmented Reality Technologies with computer vision methods, AR devices, interfaces and systems, and visualization tools. The mobile and wireless systems for Augmented Reality are discussed in Section 3. Four classes of current applications that have been explored are described in Section 4. These applications were chosen as they are the most famous type of applications encountered when researching AR apps. The future of augmented reality and the challenges they will be facing are discussed in Section 5.

In this paper we describe LiveNet, a flexible wearable platform intended for long-term ambulatory health monitoring with real-time data streaming and context classification. Based on the MIT Wearable Computing Group's distributed mobile system architecture, LiveNet is a stable, accessible system that combines inexpensive, commodity hardware; a flexible sensor/peripheral interconnection bus; and a powerful, light-weight distributed sensing, classification, and inter-process communications software architecture to facilitate the development of distributed real-time multi-modal and context-aware applications. LiveNet is able to continuously monitor a wide range of physiological signals together with the user's activity and context, to develop a personalized, data-rich health profile of a user over time. We demonstrate the power and functionality of this platform by describing a number of health monitoring applications using the LiveNet system in a variety of clinical studies th...

The artificial neural net development has had something of a renaissance in the last decade with an impressive range of application areas. From the viewpoint of telecommunication networks and systems, an increasing number of studies can be observed in recent literature dealing with proposed applications of neural nets in telecommunication environments, such as connection admission control in broadband networks, the control of high-speed interconnection networks, channel allocation in cellular mobile systems, adaptive routing, etc. These proposed applications largely use three main neural net classes: feed-forward nets with backpropagation learning, Hopfield feedback nets, and selforganising neural nets. In this paper, we first give an overview of neural net classes and their main properties, and then present a review of applications in telecommunication systems, where attention is devoted to numerical aspects such as the convergence property and learning speed of the proposed neural nets.

This article reports a unified methodology developed to evaluate the accessibility and usability of mobile computing applications, which is intended to guarantee universal access as far as possible. As a basis for the methodology, this paper presents an analysis of the accessibility guidelines, conducted to take into account the specificity of mobile systems, as well as a set of usability heuristics, specifically devised for mobile computing. Finally, it presents the results of the application of the proposed methodology to applications that have been semi-automatically developed by the MAIS Designer, a new design tool that provides applications suited to different mobile devices.

There is a need for new usability methods tailored to suit the development of mobile ICT. In response to this, three methods that have been developed to a prototype level are presented. The methods are designed to be cost-effective and provide information on (1) user problems as experienced in users’ everyday lives, (2) contexts of use, and (3) integration of technology in users’ patterns of activity. The methods have been tried out in a small scale evaluation in conjunction with the introduction of PDAs and mobile telephones with PDAs in an organisation.

The objective of this research is to introduce a new perspective to sustainable mobility strategic planning for small European municipalities – a framework for Strategic Sustainable Development (FSSD) – where back casting from a sustainable vision in the long-term future is central to the process. This vision portrays mobility in an efficient, safe and economic manner, where the use of private cars has been substituted by attractive and reliable integrated sustainable transportation modes. It is a holistic approach based on systems thinking, which provides a structure for organizing analysis and strategic planning in complex systems from the perspective of the mobility issue and the global socio-ecological system. Continuing economic development and the consequent increase in atmospheric pollution from motorized transport emissions (particularly in urbanized areas) have transformed cities into one of the big contributors to the climate change issue around the planet. Renewable energy for fuels and advanced technology mobility systems are already in place to mitigate undesirable effects of existent transportation systems. However, it has been proved that only mitigating the impact will not solve the problem, and the need for a long-term solution is urgent.

The development of radio networks has brought the problem of security specifically related to mobility of terminals sharply into focus, and has created the need for radio network operators to implement new security functionalities. The security level of the analog radio mobile systems (the so-called “first generation ” systems was very low, and these systems were often exposed to massive fraud. The development of digital radio mobile systems (the so-called “second generation” systems: GSM, DECT,. allowed the systematic introduction of cryptology based protection mechanisms. Hence, for gsm networks for instance, the main fraud and confidentiality problems were taken into account at the design stage and a security architecture was implemented to provide security services to users and network operators. The third generation mobile telecommunication systems belonging to the imt- 2000 family (which are still under specification within standardisation bodies in particular within the 3gpp worldwide third generation partnership project) will, in the forthcoming years, provide a wide variety of services on a single terminal in a multi-environment (domestic, public, business), multi-operator, and multi-service provider context. Security will be based on second generation systems security functions that have proved to be needed and reliable, and shall be adapted and improved to resolve security threats underlying to new services supplied by third generation radio systems. This document presents examples of security solutions currently implemented for protecting second generation radio mobile systems against frauds and attacks and gives an overview of potential solutions for protecting future third generation radio mobile telecommunication systems. Le développement des réseaux radiomobiles a mis en évidence des problèmes de sécurité spécifiques liés à la mobilité des terminaux, ce qui a conduit les opérateurs de ces réseaux à implanter de nouvelles fonctions de sécurité. Les systèmes analogiques dits de première génération présentaient un niveau de sécurité très faible, et nombre de ces systèmes étaient exposés à des fraudes massives. Le développement des systèmes numériques dits de deuxième génération (GSM, dect, etc.) a permis l’introduction de mécanismes de protection basés sur la cryptologie. Ainsi, pour les réseaux gsm, les principaux problèmes de fraude et de confidentialité ont été pris en compte dès la conception du système, et une architecture de sécurité a été mise en place pour offrir des services de sécurité aux usagers et aux opérateurs. Les systèmes mobiles de troisième génération de la famille imt- 2000 (dont la spécification est en cours dans divers organismes de normalisation, en particulier le projet 3gpp de partenariat mondial sur la mobilité 3g) fourniront dans les années qui viennent un large éventail de services sur un même terminal, dans un contexte multi- environnement (domestique, public, professionnel), multi-exploitant, et multi-fournisseur de services. La sécurité sera basée sur les fonctions de sécurité des systèmes de deuxième génération qui ont démontré leur utilité et leur robustesse, mais elle sera adaptée pour résoudre les menaces inhérentes aux nouveaux services qui seront offerts par ces systèmes. Cet article présente des exemples de mécanismes de sécurité actuellement utilisés pour la protection des mobiles de deuxième génération contre les fraudes et les attaques, et donne un aperçu des solutions envisagées pour la protection des systèmes mobiles de troisième génération.