Vehicular networking enhancement and multi-channel routing optimization, based on multi-objective metric and minimum spanning tree

Vehicular Ad hoc NETworks (VANETs) represent a particular mobile technology that permits the communication among vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communications paradigm, due to its flexibility to adapt to different mobile applications. VANETs are a practical example of data exchanging among real mobile nodes. To enable communications within an ad-hoc network, characterized by continuous node movements, routing protocols are needed to react to frequent changes in network topology. In this paper, the attention is focused mainly on the network layer of VANETs, proposing a novel approach to reduce the interference level during mobile transmission, based on the multi-channel nature of IEEE 802.11p (1609.4) standard. In this work a new routing protocol based on Distance Vector algorithm is presented to reduce the delay end to end and to increase packet delivery ratio (PDR) and throughput in VANETs. A new metric is also proposed, based on the maximization of the average Signal-to-Interference Ratio (SIR) level and the link duration probability between two VANET nodes. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. A Network Simulator has been used for implementing and testing the proposed idea

A Survey on Electromagnetic Interferences on Aircraft Avionics Systems and a GSM On Board System Overview

ABSTRACT Recent years have been characterized by an increase in the air traffic. More attention over micro-economic and macroeconomic indexes would be strategic to gather and enhance the safety of a flight and customer needing, for communicating by wireless handhelds on-board aircrafts. Thus, European Telecommunications Standards Institute (ETSI) proposed a GSM On Board (GSMOBA) system as a possible solution, allowing mobile terminals to communicate through GSM system on aircraft, avoiding electromagnetic interferences with radio components aboard. The main issues are directly related with interferences that could spring-out when mobile terminals attempt to connect to ground BTS, from the airplane. This kind of system is able to resolve the problem in terms of conformance of Effective Isotropic Radiated Power (EIRP) limits, defined outside the aircraft, by using an On board BTS (OBTS) and modeling the relevant key RF parameters on the air. The main purpose of this work is to illustrate the state-of-the-art of literature and previous studies about the problem, giving also a good detail of technical and normative references

Muscle function impairment in cancer patients in pre-cachexia stage

Cancer cachexia has been reported to be directly responsible for at least 20% of cancer deaths. Management of muscle wasting in cancer-associated cachexia appears to be of pivotal importance for survival of patients. In this regard, it would be interesting to identify before its patent appearance eventual functional markers of muscle damage, to plan specific exercise protocols to counteract cachexia. The muscle function of 13 oncologic patients and 15 controls was analyzed through: i) analysis of the oxidative metabolism, indirectly evaluated trough dosage of blood lactate levels before and after a submaximal incremental exercise on a treadmill; ii) analysis of strength and, iii) endurance, in both lower and upper limbs muscles, employing an isokinetic dynamometer. Statistical analyses were carried out to compare the muscle activities between groups. Analysis of oxidative metabolism during the incremental exercise on a treadmill showed that patients performed a shorter exercise than controls. Lactate levels were significantly higher in patients both at baseline and after the task. Muscle strength analysis in patients group showed a reduction of Maximum Voluntary Contraction during the isometric contraction and, a tendency to fatigue during endurance task. Data emerging from this study highlight an impairment of muscle oxidative metabolism in subjects affected by a pre-cachexia stage of cancer. A trend of precocious fatigability and an impairment of muscle strength production were also observed. This evidence underlines the relevance of assessing muscle function in order to develop novel rehabilitative approaches able to counteract motor impairment and eventually to prevent cachexia in these patients

The effects on biomechanics of walking and balance recovery in a novel pelvis exoskeleton during zero-torque control

Fall-related accidents are among the most serious concerns in elderly people, amputees and subjects with neurological disorders. The aim of this paper was to investigate the behaviour of healthy subjects wearing a novel light-weight pelvis exoskeleton controlled in zero-torque mode while carrying out unperturbed locomotion and managing unexpected perturbations. Results showed that the proposed exoskeleton was unobtrusive and had a minimum loading effect on the human biomechanics during unperturbed locomotion. Conversely, it affected the movement of the trailing leg while subjects managed unexpected slipping-like perturbations. These findings support further investigations on the potential use of powered exoskeletons to assist locomotion and, possibly prevent incipient fall

A new markovian prediction scheme for resource reservations in wireless networks with mobile hosts

Nowadays, mobile service requests in wireless networking are aimed to the benefit of a good level of satisfaction for the received Quality of Service (QoS) guarantees. In this paper, a new prediction algorithm is proposed, for the pre-reservation of passive bandwidth, when mobile users moves under radio coverage that can be considered as a cellular one (GSM, UMTS, WLAN clusters, etc.). The Hidden Markov Chains (HMC) theory is used to design the predictor, as the main component of the proposed idea, that does not depend on the considered transmission technology, mobility model or vehicular scenario. Mobile ReSerVation Protocol (MRSVP) has been used in order to realize the active/passive bandwidth reservation in the considered network topology. Different simulation campaigns have been carried out in order to appreciate the benefits of the proposed idea

NUOVI APPROCCI BIOISPIRATI PER LA PROGETTAZIONE E LA VALUTAZIONE DI MANI ARTIFICIALI

Questo lavoro di tesi ha avuto come oggetto di studio le nuove metodologie di approccio per la progettazione e la valutazione delle mani artificiali antropomorfe. Per prima cosa si è analizzato l’aspetto meccanico e cinematico; in particolare si è considerata la mano antropomorfa del robot umanoide iCub, in fase di realizzazione presso i laboratori della Scuola Superiore Sant’Anna di Pisa. La mano studiata va a completare il robot del progetto RobotCub, robot antropomorfo avente sembianza di una bambino di due anni e mezzo di età; per questo motivo anche la mano ha stesse forma e stesse dimensioni. Sono state analizzate le caratteristiche meccaniche e cinematiche; nella prima fase del lavoro, infatti, è stata focalizzata l’attenzione sull’assemblaggio delle varie parti e la movimentazione della mano. È stata condotta un’analisi per la ricerca di possibili soluzioni alternative e miglioramenti. Questo ha poi permesso di trovare e risolvere alcuni piccoli problemi meccanici (debugging). Parallelamente allo studio della mano artificiale si è ideato un protocollo di valutazione per l’analisi delle funzionalità delle mani artificiali, un protocollo che ha l’obiettivo di riempire un vuoto presente, fino a questo momento, in letteratura. Tale protocollo vuole essere completo e oggettivo per essere considerato come metodo unico di paragone e di confronto tra le mani artificiali oggigiorno esistenti. Viste le caratteristiche bioispirate dei dispositivi analizzati, lo studio è partito dai protocolli esistenti per la valutazione funzionale delle mani naturali, dai quali si è derivato un protocollo che contenesse una serie di prove per la valutazione funzionale sia di mani robotiche (semplici ed avanzate) sia per mani destinate alla sostituzione funzionale (protesi). Durante la realizzazione del protocollo per la valutazione funzionale di mani robotiche è stato anche notato che, per consentire una valutazione più ampia possibile, la mano sarebbe dovuta essere dotata di un polso. Si è quindi progettato un dispositivo che avesse funzionalità quanto più simili al polso umano. Il polso robotico progettato, realizzato usando un sistema non convenzionale, è leggero, di ridotte dimensioni, compatto, facilmente assemblabile e adattabile a varie mani robotiche (modulare) attraverso una flangia con un attacco universale. Il dispositivo presenta due gradi di libertà, attuati da tre motori, al fine di far raggiungere alla mano le configurazioni richieste dal protocollo in fase di presa e di manipolazione degli oggetti

Advanced Resources Reservation in Mobile Cellular Networks Static vs. Dynamic Approaches under Vehicular Mobility Model

Many studies in literature have shown that the bandwidth of an ongoing flow can dynamically change during multimedia sessions and an efficient bandwidth allocation scheme must be employed. This paper focuses its attention on the management of predictive services in Wireless Infrastructure Dynamic Networks. In particular, two classes of service are considered: NSIS-Mobility Independent Predictive and NSIS-Mobility Dependent Predictive, where NSIS is the Next Steps in Signaling protocol, employed for resources reservation in Integrated Services architectures. A general prediction technique is proposed, based both on the analysis of time spent into a cell by mobile nodes and on the probabilities of hand-in and hand-out events of mobile nodes from wireless cells. User mobility needs to be firstly analyzed and a novel realistic mobility model has been considered, differently from some existing works in which synthetic mobility is generated. The analysis of user mobility is mandatory when the reduction of passive resource reservations for NSIS-MIP users is desired, with a good enhancement in system utilization. Moreover, predictive reservation and admission control schemes have been integrated. The performance of the 2D wireless system is evaluated in terms of average system utilization, system outage probability, number of admitted flows and reservation prediction errors. We provided to carry out an extensive simulation campaign, in order to assess the goodness of the proposed idea: we verified that good results (in terms of perceived utility, bandwidth and admitted flows) can be obtained, outperforming also some existing works

Giuliano Vanghetti and the innovation of "cineplastic operations"

Objective: Developing functional artificial limbs for amputees has been a centuries-old challenge in medicine. We review the mechanical and neurologic principles of “cineplastic operations” and “plastic motors” used to restore movements in prostheses, with special attention to the work of Giuliano Vanghetti. Methods: We evaluated original publications describing cineplastic operations, biographic information, writings, drawings, and unpublished letters from the Vanghetti library, preserved in Empoli, Italy, and performed a bibliographic search and comparison for similar procedures in the literature. Results: Vanghetti’s method for cineplastic operations differs from similar previous methods, being the first aimed at exploiting natural movements of the remnant muscles to activate the mechanical prosthesis, and the first to do so by directly connecting the prosthesis to the residual muscles and tendons. This represented a frame-changing innovation for that time and paved the way for current neuroprosthetic approaches. The first description of the method was published in 1898 and human studies started in 1900. The results of these studies were presented in 1905 and published in 1906 in Plastic and Kinematic Prosthesis. A German surgeon, Ferdinand Sauerbruch, often acknowledged as the inventor of the method, published his first results in 1915. Conclusions: Vanghetti was the first to accurately performand describe cineplastic operations for patients following an upper arm amputation. He considered the neurologic implications of the problem and, perhaps in an effort to provide more appropriate proprioceptive feedback, he intuitively applied the prostheses so that they were functionally activated by the muscles of the proximal stum

Mobility analysis for passive reservations in vehicular cellular networks based on dynamic programming and roads compression

The employment of an appropriate Bandwidth Management Scheme (BMS) is needed in wireless networking, given that the main desire of end-users is to take advantage of satisfactory services, in terms of Quality of Service (QoS), especially when a particular charge is paid to meet the requirement. In this paper the authors are interested in investigating how the continuity of services can be guaranteed in QoS networks, when users move from a cell to another one, under an infrastructure cellular coverage. The only way to face this issue is represented by the employment of in-advance bandwidth reservations, although it leads the system to waste bandwidth resources, since they are not used until the mobile host enters the coverage cell where the passive request has been made. A new scheme for predicting user movements is proposed, taking the advantage of the dynamic programming approach, that is able to reduce the number of possible roads to be considered and thereby increasing/decreasing the accuracy/redundancy of the proposed model. Several simulation runs have been carried out in order to assess the effectiveness of the proposed idea.Web of Science8415