Strategie di offerta di servizi streaming in Internet: Studio di caso "Amazon-Twitch"

Internet è la rete globale a cui si può avere accesso in modo estremamente facile, consentendo praticamente a chiunque di inserire i propri contenuti in tempi rapidi, a costi quasi nulli e senza limitazioni geografiche. Il progresso tecnologico e la maggiore disponibilità della banda larga, uniti alle nuove modalità di fruizione ed ai nuovi format, hanno portato ben il 70% degli web users a vedere video online regolarmente. La popolarità dei servizi di streaming video è cresciuta rapidamente, tanto da registrare dei dati di traffico impressionanti negli ultimi due anni. Il campo applicativo della tesi è Twitch, il più celebre servizio di streaming che è riuscito ad imporsi come quarto sito negli Stati Uniti per traffico Internet: un dato sorprendente se pensiamo che si occupa solo di videogiochi. Il fenomeno Twitch è destinato a durare, lo dimostrano i 970 milioni di dollari investiti da Amazon nel 2014 per acquistare la piattaforma, diventata così una sussidiaria di Amazon. L'obiettivo della tesi è stato lo studio di mercato della piattaforma, attraverso il recupero e l'analisi delle informazioni reperibili in letteratura, nonché attraverso estrapolazione di dati originari mediante le API del sito. Si è proceduto all’analisi delle caratteristiche del mercato servito, in termini di segmentazione effettiva, rivolta alla messa in evidenza della possibile dipendenza dai comportamenti dei player, con particolare attenzione alla possibile vulnerabilità.

FastLApp: Un'applicazione Android per la telemetria di motocicli su strada e su pista

L'elaborato tratta del progetto di tesi "FastLApp". "FastLApp" e un'applicazione per la piattaforma Android che si pone come obbiettivo l'acquisizione dei dati di telemetria relativi al comportamento di un motoveicolo su strada e su circuito e come target i motociclisti amatoriali. Dopo un'introduzione sul sistema operativo Android, sulle principali tecniche di telemetria e di acquisizione dati e sulle applicazioni correlate, vengono descritte le funzionalita, l'implementazione e il testing del applicazione oggetto di tesi. Dopo una breve descrizione degli strumenti e delle tecnologie utilizzate, viene infine data una valutazione all'applicazione e discussi i suoi eventuali sviluppi futuri.

Un approccio Javascript-based per la realizzazione di app multipiattaforma

Il mondo degli smartphone, in particolare grazie all’avvento delle app, costituisce un settore che ha avuto negli ultimi anni una crescita tale, da richiedere l’introduzione di un nuovo termine in ambito finanziario: app economy. La crescente richiesta da parte del mercato di nuove opportunitá derivanti dal mondo delle applicazioni, ha aumentato sensibilmente il carico di lavoro richiesto alle software house specializzate,che hanno pertanto avuto la necessitá di adeguarsi a tale cambiamento. Per ovviare alle suddette problematiche, sono iniziati ad emergere due tool che consentono lo sviluppo di applicazioni multipiattaforma utilizzando un linguaggio ed un ambiente di sviluppo comuni. Tali sistemi consentono un risparmio in termini di tempi e costi, ma non sono in grado di competere con i tool nativi in termini di qualità del prodotto realizzato, in particolare per quanto concerne l'interfaccia grafica. Si propone pertanto un approccio che tenta di combinare i vantaggi di entrambe le soluzioni, al fine di ottimizzare la fluidità della UI, consentendo allo stesso tempo il riuso della logica applicativa.

Posizionamento Indoor tramite lo studio della pressione atmosferica

La diffusione e l'evoluzione degli smartphone hanno permesso una rapida espansione delle informazioni che e possibile raccogliere tramite i sensori dei dispositivi, per creare nuovi servizi per gli utenti o potenziare considerevolmente quelli gia esistenti, come ad esempio quelli di emergenza. In questo lavoro viene esplorata la capacita dei dispositivi mobili di fornire, tramite il calcolo dell'altitudine possibile grazie alla presenza del sensore barometrico all'interno di sempre piu dispositivi, il piano dell'edificio in cui si trova l'utente, attraverso l'analisi di varie metodologie con enfasi sulle problematiche dello stazionamento a lungo termine. Tra le metodologie vengono anche considerati sistemi aventi accesso ad una informazione proveniente da un dispositivo esterno e ad una loro versione corretta del problema dei differenti hardware relativi ai sensori. Inoltre viene proposto un algoritmo che, sulla base delle sole informazioni raccolte dal sensore barometrico interno, ha obbiettivo di limitare l'errore generato dalla naturale evoluzione della pressione atmosferica durante l'arco della giornata, distinguendo con buona precisione uno spostamento verticale quale un movimento tra piani, da un cambiamento dovuto ad agenti, quali quelli atmosferici, sulla pressione. I risultati ottenuti dalle metodologie e loro combinazioni analizzate vengono mostrati sia per singolo campionamento, permettendo di confrontare vantaggi e svantaggi dei singoli metodi in situazioni specifiche, sia aggregati in casi d'uso di possibili utenti aventi diverse necessita di stazionamento all'interno di un edificio.

A Personalized Privacy Management Framework for Android Applications

Ogni giorno, l'utente di smartphon e tablet, spesso senza rendersene conto, condivide, tramite varie applicazioni, un'enorme quantità di informazioni. Negli attuali sistemi operativi, l'assenza di meccanismi utili a garantire adeguatamente l'utente, ha spinto questo lavoro di ricerca verso lo sviluppo di un inedito framework.È stato necessario uno studio approfondito dello stato dell'arte di soluzioni con gli stessi obiettivi. Sono stati esaminati sia modelli teorici che pratici, con l'analisi accurata del relativo codice. Il lavoro, in stretto contatto con i colleghi dell'Università Centrale della Florida e la condivisione delle conoscenze con gli stessi, ha portato ad importanti risultati. Questo lavoro ha prodotto un framework personalizzato per gestire la privacy nelle applicazioni mobili che, nello specifico, è stato sviluppato per Android OS e necessita dei permessi di root per poter realizzare il suo funzionamento. Il framework in questione sfrutta le funzionalità offerte dal Xposed Framework, con il risultato di implementare modifiche al sistema operativo, senza dover cambiare il codice di Android o delle applicazioni che eseguono su quest’ultimo. Il framework sviluppato controlla l’accesso da parte delle varie applicazioni in esecuzione verso le informazioni sensibili dell’utente e stima l’importanza che queste informazioni hanno per l’utente medesimo. Le informazioni raccolte dal framework sulle preferenze e sulle valutazioni dell’utente vengono usate per costruire un modello decisionale che viene sfruttato da un algoritmo di machine-learning per migliorare l’interazione del sistema con l’utente e prevedere quelle che possono essere le decisioni dell'utente stesso, circa la propria privacy. Questo lavoro di tesi realizza gli obbiettivi sopra citati e pone un'attenzione particolare nel limitare la pervasività del sistema per la gestione della privacy, nella quotidiana esperienza dell'utente con i dispositivi mobili.

Servizi Sociali Territoriali e Università: Esempi di Sinergie Possibili per un Percorso di Qualità

Although – or because – social work education in Italy has for some 15 years now been exclusively in the domain of the university the relationship between the academic world and that of practice has been highly tenuous. Research is indeed being conducted by universities, but rarely on issues that are of immediate practice relevance. This means that forms of practice develop and become established habitually which are not checked against rigorous standards of research and that the creation of knowledge at academic level pays scant attention to the practice implications of social changes. This situation has been made even worse by the dwindling resources both in social services and at the level of the universities which means that bureaucratic procedures or imports of specialisations from other disciplines frequently dominate the development of practice instead of a theory-based approach to methodology. This development does not do justice to the actual requirements of Italian society faced with ever increasing post-modern complexity which is reflected also in the nature of social problems because it implies a continuation of a faith in modernity with its idea of technical, clear-cut solutions while social relations have decidedly moved beyond that belief. This discrepancy puts even greater strain on the personnel of welfare agencies and does ultimately not satisfy the ever increasing demands for quality and accountability of services on the part of users and the general public. Social workers badly lack fundamental theoretical reference points which could guide them in their difficult work to arrive at autonomous, situation-specific methodological answers not based on procedures but on analytical knowledge. Thirty years ago, in 1977, a Presidential Decree created the legal basis for the establishment of social service departments at the level of municipalities which created opportunities for the direct involvement of the community in the fight against exclusion. For this potential to be fully utilized it would have required the bringing together of three dimensions, the organizational structure, the opportunities for learning and research in the territory and the contribution by the professional community. As this did not occur social services in Italy still often retain the character of charity which does not concern itself with the actual causes of poverty and exclusion. This in turn affects the relationship with citizens in general who cannot develop trust in those services. Through uncritical processes of interaction Edgar Morin’s dictum manifests itself which is that without resorting to critical reflection on complexity interventions can often have an effect that totally the opposite to the original intention. An important element in setting up a dynamic interchange between academia and practice is the placement on professional social work courses. Here the looping of theory to practice and back to theory etc. can actually take place under the right organizational and conceptual conditions, more so than in abstract, and for practitioners often useless debates about the theory-practice connection. Furthermore, research projects at the University of Florence Social Work Department for instance aim at fostering theoretical reflection at the level of and with the involvement of municipal social service agencies. With a general constructive disposition towards research and some financial investment students were facilitated to undertake social service practice related research for their degree theses for instance in the city of Pistoia. In this way it was also possible to strengthen the confidence and professional identity of social workers as they became aware of the contribution their own discipline can make to practice-relevant research instead of having to move over to disciplines like psychology for those purposes. Examples of this fruitful collaboration were presented at a conference in Pistoia on 25 June 2007. One example is a thesis entitled ‘The object of social work’ and examines the difficult development of definitions of social work and comes to the conclusion that ‘nothing is more practical than a theory’. Another is on coping abilities as a necessary precondition for the utilization of resources supplied by social services in exceptional circumstances. Others deal with the actual sequence of interventions in crisis situations, and one very interestingly looks at time and how it is being constructed often differently by professionals and clients. At the same time as this collaboration on research gathers momentum in the Toscana, supervision is also being demanded more forcefully as complementary to research and with the same aim of profiling more strongly the professional identity of social work. Collaboration between university and social service filed is for mutual benefit. At a time when professional practice is under threat of being defined from the outside through bureaucratic prescriptions a sound grounding in theory is a necessary precondition for competent practice.

From big smartphone data to worldwide research: The Mobile Data Challenge

This paper presents an overview of the Mobile Data Challenge (MDC), a large-scale research initiative aimed at generating innovations around smartphone-based research, as well as community-based evaluation of mobile data analysis methodologies. First, we review the Lausanne Data Collection Campaign (LDCC), an initiative to collect unique longitudinal smartphone dataset for the MDC. Then, we introduce the Open and Dedicated Tracks of the MDC, describe the specific datasets used in each of them, discuss the key design and implementation aspects introduced in order to generate privacy-preserving and scientifically relevant mobile data resources for wider use by the research community, and summarize the main research trends found among the 100+ challenge submissions. We finalize by discussing the main lessons learned from the participation of several hundred researchers worldwide in the MDC Tracks.

Towards End-User Driven Power Saving Control in Android devices

Abstract. During the last decade mobile communications increasingly became part of people's daily routine. Such usage raises new challenges regarding devices' battery lifetime management when using most popular wireless access technologies, such as IEEE 802.11. This paper investigates the energy/delay trade-off of using an end-user driven power saving approach, when compared with the standard IEEE 802.11 power saving algorithms. The assessment was conducted in a real testbed using an Android mobile phone and high-precision energy measurement hardware. The results show clear energy benefits of employing user-driven power saving techniques, when compared with other standard approaches.

Verloren im Patentdickicht oder Ein Smartphone ist kein Lastkahn

Unglaublich, aber wahr: Wir versuchen heutiges Hightech mit Patentgesetzen in den Griff zu bekommen, die aus dem 15. Jahrhundert stammen. Das kann nicht gutgehen. Ein kleiner historischer Abriss.

Crowdsourcing language change with smartphone applications

Crowdsourcing linguistic phenomena with smartphone applications is relatively new. In linguistics, apps have predominantly been developed to create pronunciation dictionaries, to train acoustic models, and to archive endangered languages. This paper presents the first account of how apps can be used to collect data suitable for documenting language change: we created an app, Dialäkt Äpp (DÄ), which predicts users’ dialects. For 16 linguistic variables, users select a dialectal variant from a drop-down menu. DÄ then geographically locates the user’s dialect by suggesting a list of communes where dialect variants most similar to their choices are used. Underlying this prediction are 16 maps from the historical Linguistic Atlas of German-speaking Switzerland, which documents the linguistic situation around 1950. Where users disagree with the prediction, they can indicate what they consider to be their dialect’s location. With this information, the 16 variables can be assessed for language change. Thanks to the playfulness of its functionality, DÄ has reached many users; our linguistic analyses are based on data from nearly 60,000 speakers. Results reveal a relative stability for phonetic variables, while lexical and morphological variables seem more prone to change. Crowdsourcing large amounts of dialect data with smartphone apps has the potential to complement existing data collection techniques and to provide evidence that traditional methods cannot, with normal resources, hope to gather. Nonetheless, it is important to emphasize a range of methodological caveats, including sparse knowledge of users’ linguistic backgrounds (users only indicate age, sex) and users’ self-declaration of their dialect. These are discussed and evaluated in detail here. Findings remain intriguing nevertheless: as a means of quality control, we report that traditional dialectological methods have revealed trends similar to those found by the app. This underlines the validity of the crowdsourcing method. We are presently extending DÄ architecture to other languages.

Documenting sound change with smartphone apps

Crowdsourcing linguistic phenomena with smartphone applications is relatively new. Apps have been used to train acoustic models for automatic speech recognition (de Vries et al. 2014) and to archive endangered languages (Iwaidja Inyaman Team 2012). Leemann and Kolly (2013) developed a free app for iOS—Dialäkt Äpp (DÄ) (>78k downloads)—to document language change in Swiss German. Here, we present results of sound change based on DÄ data. DÄ predicts the users’ dialects: for 16 variables, users select their dialectal variant. DÄ then tells users which dialect they speak. Underlying this prediction are maps from the Linguistic Atlas of German-speaking Switzerland (SDS, 1962-2003), which documents the linguistic situation around 1950. If predicted wrongly, users indicate their actual dialect. With this information, the 16 variables can be assessed for language change. Results revealed robustness of phonetic variables; lexical and morphological variables were more prone to change. Phonetic variables like to lift (variants: /lupfə, lʏpfə, lipfə/) revealed SDS agreement scores of nearly 85%, i.e., little sound change. Not all phonetic variables are equally robust: ladle (variants: /xælə, xællə, xæuə, xæɫə, xæɫɫə/) exhibited significant sound change. We will illustrate the results using maps that show details of the sound changes at hand.

GoCARB: Smartphone-App zur Kohlenhydratberechnung bei Typ-1-Diabetes

Smartphone-App zur Kohlenhydratberechnung Neue Technologien wie Blutzuckersensoren und moderne Insulinpumpen prägten die Therapie des Typ-1-Diabetes (T1D) in den letzten Jahren in wesentlichem Ausmaß. Smartphones sind aufgrund ihrer rasanten technischen Entwicklung eine weitere Plattform für Applikationen zur Therapieunterstützung bei T1D. GoCARB Hierbei handelt es sich um ein zur Kohlenhydratberechnung entwickeltes System für Personen mit T1D. Die Basis für Endanwender stellt ein Smartphone mit Kamera dar. Zur Berechnung werden 2 mit dem Smartphone aus verschiedenen Winkeln aufgenommene Fotografien einer auf einem Teller angerichteten Mahlzeit benötigt. Zusätzlich ist eine neben dem Teller platzierte Referenzkarte erforderlich. Die Grundlage für die Kohlenhydratberechnung ist ein Computer-Vision-gestütztes Programm, das die Mahlzeiten aufgrund ihrer Farbe und Textur erkennt. Das Volumen der Mahlzeit wird mit Hilfe eines dreidimensional errechneten Modells bestimmt. Durch das Erkennen der Art der Mahlzeiten sowie deren Volumen kann GoCARB den Kohlenhydratanteil unter Einbeziehung von Nährwerttabellen berechnen. Für die Entwicklung des Systems wurde eine Bilddatenbank von mehr als 5000 Mahlzeiten erstellt und genutzt. Resümee Das GoCARB-System befindet sich aktuell in klinischer Evaluierung und ist noch nicht für Patienten verfügbar.

Localization and activity detection Based on the fusion of environment And inertial sensors = Localización y detección de actividad Basadas en integración de sensores y dispositivos inerciales

Los sensores inerciales (acelerómetros y giróscopos) se han ido introduciendo poco a poco en dispositivos que usamos en nuestra vida diaria gracias a su minituarización. Hoy en día todos los smartphones contienen como mínimo un acelerómetro y un magnetómetro, siendo complementados en losmás modernos por giróscopos y barómetros. Esto, unido a la proliferación de los smartphones ha hecho viable el diseño de sistemas basados en las medidas de sensores que el usuario lleva colocados en alguna parte del cuerpo (que en un futuro estarán contenidos en tejidos inteligentes) o los integrados en su móvil. El papel de estos sensores se ha convertido en fundamental para el desarrollo de aplicaciones contextuales y de inteligencia ambiental. Algunos ejemplos son el control de los ejercicios de rehabilitación o la oferta de información referente al sitio turístico que se está visitando. El trabajo de esta tesis contribuye a explorar las posibilidades que ofrecen los sensores inerciales para el apoyo a la detección de actividad y la mejora de la precisión de servicios de localización para peatones. En lo referente al reconocimiento de la actividad que desarrolla un usuario, se ha explorado el uso de los sensores integrados en los dispositivos móviles de última generación (luz y proximidad, acelerómetro, giróscopo y magnetómetro). Las actividades objetivo son conocidas como ‘atómicas’ (andar a distintas velocidades, estar de pie, correr, estar sentado), esto es, actividades que constituyen unidades de actividades más complejas como pueden ser lavar los platos o ir al trabajo. De este modo, se usan algoritmos de clasificación sencillos que puedan ser integrados en un móvil como el Naïve Bayes, Tablas y Árboles de Decisión. Además, se pretende igualmente detectar la posición en la que el usuario lleva el móvil, no sólo con el objetivo de utilizar esa información para elegir un clasificador entrenado sólo con datos recogidos en la posición correspondiente (estrategia que mejora los resultados de estimación de la actividad), sino también para la generación de un evento que puede producir la ejecución de una acción. Finalmente, el trabajo incluye un análisis de las prestaciones de la clasificación variando el tipo de parámetros y el número de sensores usados y teniendo en cuenta no sólo la precisión de la clasificación sino también la carga computacional. Por otra parte, se ha propuesto un algoritmo basado en la cuenta de pasos utilizando informaiii ción proveniente de un acelerómetro colocado en el pie del usuario. El objetivo final es detectar la actividad que el usuario está haciendo junto con la estimación aproximada de la distancia recorrida. El algoritmo de cuenta pasos se basa en la detección de máximos y mínimos usando ventanas temporales y umbrales sin requerir información específica del usuario. El ámbito de seguimiento de peatones en interiores es interesante por la falta de un estándar de localización en este tipo de entornos. Se ha diseñado un filtro extendido de Kalman centralizado y ligeramente acoplado para fusionar la información medida por un acelerómetro colocado en el pie del usuario con medidas de posición. Se han aplicado también diferentes técnicas de corrección de errores como las de velocidad cero que se basan en la detección de los instantes en los que el pie está apoyado en el suelo. Los resultados han sido obtenidos en entornos interiores usando las posiciones estimadas por un sistema de triangulación basado en la medida de la potencia recibida (RSS) y GPS en exteriores. Finalmente, se han implementado algunas aplicaciones que prueban la utilidad del trabajo desarrollado. En primer lugar se ha considerado una aplicación de monitorización de actividad que proporciona al usuario información sobre el nivel de actividad que realiza durante un período de tiempo. El objetivo final es favorecer el cambio de comportamientos sedentarios, consiguiendo hábitos saludables. Se han desarrollado dos versiones de esta aplicación. En el primer caso se ha integrado el algoritmo de cuenta pasos en una plataforma OSGi móvil adquiriendo los datos de un acelerómetro Bluetooth colocado en el pie. En el segundo caso se ha creado la misma aplicación utilizando las implementaciones de los clasificadores en un dispositivo Android. Por otro lado, se ha planteado el diseño de una aplicación para la creación automática de un diario de viaje a partir de la detección de eventos importantes. Esta aplicación toma como entrada la información procedente de la estimación de actividad y de localización además de información almacenada en bases de datos abiertas (fotos, información sobre sitios) e información sobre sensores reales y virtuales (agenda, cámara, etc.) del móvil. Abstract Inertial sensors (accelerometers and gyroscopes) have been gradually embedded in the devices that people use in their daily lives thanks to their miniaturization. Nowadays all smartphones have at least one embedded magnetometer and accelerometer, containing the most upto- date ones gyroscopes and barometers. This issue, together with the fact that the penetration of smartphones is growing steadily, has made possible the design of systems that rely on the information gathered by wearable sensors (in the future contained in smart textiles) or inertial sensors embedded in a smartphone. The role of these sensors has become key to the development of context-aware and ambient intelligent applications. Some examples are the performance of rehabilitation exercises, the provision of information related to the place that the user is visiting or the interaction with objects by gesture recognition. The work of this thesis contributes to explore to which extent this kind of sensors can be useful to support activity recognition and pedestrian tracking, which have been proven to be essential for these applications. Regarding the recognition of the activity that a user performs, the use of sensors embedded in a smartphone (proximity and light sensors, gyroscopes, magnetometers and accelerometers) has been explored. The activities that are detected belong to the group of the ones known as ‘atomic’ activities (e.g. walking at different paces, running, standing), that is, activities or movements that are part of more complex activities such as doing the dishes or commuting. Simple, wellknown classifiers that can run embedded in a smartphone have been tested, such as Naïve Bayes, Decision Tables and Trees. In addition to this, another aim is to estimate the on-body position in which the user is carrying the mobile phone. The objective is not only to choose a classifier that has been trained with the corresponding data in order to enhance the classification but also to start actions. Finally, the performance of the different classifiers is analysed, taking into consideration different features and number of sensors. The computational and memory load of the classifiers is also measured. On the other hand, an algorithm based on step counting has been proposed. The acceleration information is provided by an accelerometer placed on the foot. The aim is to detect the activity that the user is performing together with the estimation of the distance covered. The step counting strategy is based on detecting minima and its corresponding maxima. Although the counting strategy is not innovative (it includes time windows and amplitude thresholds to prevent under or overestimation) no user-specific information is required. The field of pedestrian tracking is crucial due to the lack of a localization standard for this kind of environments. A loosely-coupled centralized Extended Kalman Filter has been proposed to perform the fusion of inertial and position measurements. Zero velocity updates have been applied whenever the foot is detected to be placed on the ground. The results have been obtained in indoor environments using a triangulation algorithm based on RSS measurements and GPS outdoors. Finally, some applications have been designed to test the usefulness of the work. The first one is called the ‘Activity Monitor’ whose aim is to prevent sedentary behaviours and to modify habits to achieve desired objectives of activity level. Two different versions of the application have been implemented. The first one uses the activity estimation based on the step counting algorithm, which has been integrated in an OSGi mobile framework acquiring the data from a Bluetooth accelerometer placed on the foot of the individual. The second one uses activity classifiers embedded in an Android smartphone. On the other hand, the design of a ‘Travel Logbook’ has been planned. The input of this application is the information provided by the activity and localization modules, external databases (e.g. pictures, points of interest, weather) and mobile embedded and virtual sensors (agenda, camera, etc.). The aim is to detect important events in the journey and gather the information necessary to store it as a journal page.