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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Mobile Crowd Sensing in Edge Computing Environment

January 2019 (has links)
abstract: The mobile crowdsensing (MCS) applications leverage the user data to derive useful information by data-driven evaluation of innovative user contexts and gathering of information at a high data rate. Such access to context-rich data can potentially enable computationally intensive crowd-sourcing applications such as tracking a missing person or capturing a highlight video of an event. Using snippets and pictures captured from multiple mobile phone cameras with specific contexts can improve the data acquired in such applications. These MCS applications require efficient processing and analysis to generate results in real time. A human user, mobile device and their interactions cause a change in context on the mobile device affecting the quality contextual data that is gathered. Usage of MCS data in real-time mobile applications is challenging due to the complex inter-relationship between: a) availability of context, context is available with the mobile phones and not with the cloud, b) cost of data transfer to remote cloud servers, both in terms of communication time and energy, and c) availability of local computational resources on the mobile phone, computation may lead to rapid battery drain or increased response time. The resource-constrained mobile devices need to offload some of their computation. This thesis proposes ContextAiDe an end-end architecture for data-driven distributed applications aware of human mobile interactions using Edge computing. Edge processing supports real-time applications by reducing communication costs. The goal is to optimize the quality and the cost of acquiring the data using a) modeling and prediction of mobile user contexts, b) efficient strategies of scheduling application tasks on heterogeneous devices including multi-core devices such as GPU c) power-aware scheduling of virtual machine (VM) applications in cloud infrastructure e.g. elastic VMs. ContextAiDe middleware is integrated into the mobile application via Android API. The evaluation consists of overheads and costs analysis in the scenario of ``perpetrator tracking" application on the cloud, fog servers, and mobile devices. LifeMap data sets containing actual sensor data traces from mobile devices are used to simulate the application run for large scale evaluation. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
82

AskBird: The Mobile Experience Sampling Toolkit

Mobedi, Pedram January 2014 (has links)
Experience Sampling Method is a modern approach of studying human behavior. This research methodology is used in psycho-metrics to ask participant to provide feedback regarding the state of their health, opinion, etc. The collected data is then probed, analyzed and used for creating related statistical predictions. Despite the remarkable data that is produced with ESM, receiving data from the participants is not a straightforward task. It could either be via physical presence of the participant in certain labs or through special hand-held devices that are sometimes difficult to carry, maintain and use. A more advanced version of ESM is Mobile Experience Sampling Method . As mobile devices have become the de facto standard in human communication as well as ubiquitous multi-purpose portable devices, taking advantage of their features, especially their location-awareness functionality can help improve the experience sampling method. Therefore the focus of this thesis is on improving the method byimplementing a versatile mobile experience sampling toolkit that is locationaware and easy to use.
83

Activity-Centric Prioritized Streaming of Games to Mobile Devices

Rahimi Koopayi, Hesam Aldin January 2012 (has links)
As mobile devices still have limited battery life, processing power, memory, and display size, they cannot yet execute gaming applications with the same fidelity and quality as their PC counterparts. In response, researchers have recently performed research with the goal of the real-time delivery of game content specifically to fit within mobile devices’ limitations. In this thesis, we present a novel approach to tackling the streaming of objects to mobile devices. Our goal is to reduce the number of objects subject to streaming from the server to the target devices, while not violating the user-defined limitations through an efficient, context-aware 3D object selection and prioritization scheme. We take advantage of the game context to stream only the most relevant objects. Our evaluations have shown that this technique not only leads to better performance in general, but also increases the gameplay experience by helping the player to achieve a higher score.
84

Geofencing-teknik för synkronisering av en kontextmedveten ljudvandring

Zetterström, Oskar, Sadikovic, Amar January 2018 (has links)
Människan har genom tiderna använt sig av många hjälpmedel för navigering, från attfölja stjärnorna till dagens användning av “Global Positioning System” (GPS).Föreliggande studie inriktar sig på kontextmedvetna ljudvandringar, exempelvis i formav en guidad tur genom en stad där rösten i ljudklippet berättar om sevärdheter ianvändarens närhet. Att spela upp ett enda sammanhängande ljudklipp för en helljudvandring ger utrymme för komplikationer. Ett problem som kan uppstå är attanvändaren går för fort eller för långsamt genom sträckan, resulterande i attanvändarens position inte överensstämmer med det ljudspåret berättar om. Med syfteatt skapa en kontextmedveten ljudvandring presenterar studien förslag på enapplikation som erbjuder en lösning på förevarande problem. Applikationen utveckladesi Android studio och tillämpar GPS-koordinater samt geofencing-teknik för att lokaliseraanvändarens position. Varje geofenceområde har storleken 50x40 meter och konstruerassom en vandring. Områdena tilldelas ett specifikt ljudklipp som spelas upp näranvändaren befinner sig inom området. För att evaluera vår applikation utfördesanvändartester på en testvandring som placerades utanför Malmö universitet.Resultaten av användartesterna visar att deltagarna upplevde att ljudet stämde överensmed den plats de befann sig på. / The humankind has used many tools to navigate, from following stars to using theGlobal Positioning System (GPS). This study focuses on context-aware soundwalks, e.g.it could be a guided tour through a city where the voice in the audio describes touristattractions in the user’s surroundings. Complications can arise when playing onecontinuous sound clip through an entire soundwalk. For instance, if the user is walkingthe distance too fast or too slow, resulting in the user’s position not corresponding withthe content in the audio track. In this paper we introduce an application that serves as asolution to the problems that may arise when creating context-aware soundwalks. Theapplication was developed in Android studio and uses GPS coordinates and geofencingtechnology to determinate the user’s location. Each geofence was given the size of 50x40meters and together they form a soundwalk. The geofences were also assigned a specificaudio clip that started playing when the user entered the geofence. To evaluate ourapplication user tests were designed. The tests were conducted on a soundwalk locatedoutside of Malmö University. Based on the results of our user tests the participantsfound that the sound was consistent with the place they were located.
85

Improving the Privacy, Usability, and Context-Awareness of Smart Speakers

Alrumayh, Abrar S., 0000-0003-2275-0729 January 2022 (has links)
Smart speakers, such as the Amazon Echo or Google Home, have become ubiquitous in our daily lives due to their convenience, which offers interactive actions through the use of simple voice commands. These devices allow users to issue a wide range of commands for a variety of services. Users can ask in natural language questions about the weather, stock market, online shopping orders, and other general information. These devices can also be used to control lights, and heating systems, and set timers and alarms in the smart home. However, as smart speaker systems become more prevalent, new security and privacy, usability, and context awareness concerns will need to be explored and addressed. In this dissertation, we carry out the effort to understand and mitigate privacy leaks from third-party applications, improve usability testing using interactability metrics, and improve context-awareness in a multi-occupant home using background sounds. We first study the privacy risks resulting from smart speaker apps developed by third-party developers. Having a device permanently on and always listening led to concerns over user privacy. In addition, the use of the third-party app on smart speaker platforms introduces arguably more serious privacy risks than using only the platform's built-in apps, due to the open nature of the app marketplaces. We explore how an adversary can efficiently create a valid smart speaker app to eavesdrop on users. We developed three different strategies for implementing a malicious app. To mitigate this threat, we propose a strategy for users to limit the success of this adversary. We designed a measurement app to look at the effect of various environmental factors in the home impacting what the third party can hear, and therefore provide users with a recommendation to place their smart speaker in locations that limit the success of this adversary. Next, we propose the idea of an interactability score to quantify how well a smart speaker app can accept potentially different ways a user may express their commands. However, voice-generated input data creates many unpredictable test cases since there are many different ways of how someone will express the same intention. In addition, each third-party developer could implement their own voice commands, making it difficult for users to remember what commands a particular app can process. The architecture of current smart speaker apps further complicates the testing process since the app is hosted on the smart speaker platform as a black-box. Therefore, we develop a testing framework to automatically and systematically evaluate the interactability of the smart speaker applications. It measures how well an app has been implemented to accept different kinds of user interaction. We also focus on improving context-awareness access control for smart speakers. The convenience of these devices is tempered by the possibility of performing unintended or intended actions. At home, the device is usually placed in a fixed location and accessed by multiple people with complex relationships between them, and these complex relationships can lead to complex access control requirements, where the context factors and interpersonal relationships should play a significant role. We design a system to be run on a smart speaker that makes use of the sounds in the home to estimate the current state of the house, e.g. number of occupants, activities being engaged, social relation of occupants, etc. This context information is used to decide whether to execute the command, prompt for confirmation or reject the command entirely. We also designed a simple pictorial configuration utility to help non-expert users configure their access rules. / Computer and Information Science
86

A context-aware application mobility approach

Johansson, Dan January 2012 (has links)
Over the last two decades, mobile computing has gone from being a mere vision to becoming a reality, ubiquitously present in our everyday lives. There are different types of mobility, from user and terminal mobility, to mobility of services and sessions. This thesis is mainly about application mobility { the ability for an application to migrate between different host devices during its execution. The aim of this thesis work is to explore and advance the area of application mobility. The thesis approaches this goal through focusing on three research issues: Architectural considerations for application mobility; Context-awareness support and application adaptability; and Concept exploration.The contributions of this thesis include the identification of requirements for application mobility and a proposal for a decentralized, global scale architecture for application mobility, building on the peer-to-peer paradigm. Several prototypes of systems allowing application mobility are deployed, manifesting concepts such as decentralized system layout, context-awareness, context quality and global scope. Evaluations are both quantitative and qualitative. Other contributions of this thesis are the design and evaluation of a framework building on cloud and peer-to-peer technology to enable mobile sessions and an exploration of the concept of application mobility. / Sense Smart City, MOSA - mobil och öppen tjänste-access, NIMO - Nordic Interaction and Mobility Research Platform
87

A Context-Aware Approach to Android Memory Management

Muthu, Srinivas 14 November 2016 (has links)
No description available.
88

Context Sensitive Interaction Interoperability for Distributed Virtual Environments

Ahmed, Hussein Mohammed 23 June 2010 (has links)
The number and types of input devices and related interaction technique types are growing rapidly. Innovative input devices such as game controllers are no longer used just for games, propriety consoles and specific applications, they are also used in many distributed virtual environments, especially the so-called serious virtual environments. In this dissertation a distributed, service based framework is presented to offer context-sensitive interaction interoperability that can support mapping between input devices and suitable application tasks given the attributes (device, applications, users, and interaction techniques) and the current user context without negatively impacting performances of large scale distributed environments. The mapping is dynamic and context sensitive taking into account the context dimensions of both the virtual and real planes. What device or device component to use, how and when to use them depend on the application, task performed, the user and the overall context, including location and presence of other users. Another use of interaction interoperability is as a testbed for input devices, and interaction techniques making it possible to test reality based interfaces and interaction techniques with legacy applications. The dissertation provides a description how the framework provides these affordances and a discussion of motivations, goals and the addressed challenges. Several proof of the concept implementations were developed and an evaluation of the framework performance (in terms of system characteristics) demonstrates viability, scalability and negligible delays. / Ph. D.
89

Cognizant Networks: A Model and Framework for Session-based Communications and Adaptive Networking

Kalim, Umar 09 August 2017 (has links)
The Internet has made tremendous progress since its inception. The kingpin has been the transmission control protocol (TCP), which supports a large fraction of communication. With the Internet's wide-spread access, users now have increased expectations. The demands have evolved to an extent which TCP was never designed to support. Since network stacks do not provide the necessary functionality for modern applications, developers are forced to implement them over and over again --- as part of the application or supporting libraries. Consequently, application developers not only bear the burden of developing application features but are also responsible for building networking libraries to support sophisticated scenarios. This leads to considerable duplication of effort. The challenge for TCP in supporting modern use cases is mostly due to limiting assumptions, simplistic communication abstractions, and (once expedient) implementation shortcuts. To further add to the complexity, the limited TCP options space is insufficient to support extensibility and thus, contemporary communication patterns. Some argue that radical changes are required to extend the networks functionality; some researchers believe that a clean slate approach is the only path forward. Others suggest that evolution of the network stack is necessary to ensure wider adoption --- by avoiding a flag day. In either case, we see that the proposed solutions have not been adopted by the community at large. This is perhaps because the cost of transition from the incumbent to the new technology outweighs the value offered. In some cases, the limited scope of the proposed solutions limit their value. In other cases, the lack of backward compatibility or significant porting effort precludes incremental adoption altogether. In this dissertation, we focus on the development of a communication model that explicitly acknowledges the context of the conversation and describes (much of) modern communications. We highlight how the communication stack should be able to discover, interact with and use available resources to compose richer communication constructs. The model is able to do so by using session, flow and endpoint abstractions to describe communications between two or more endpoints. These abstractions provide means to the application developers for setting up and manipulating constructs, while the ability to recognize change in the operating context and reconfigure the constructs allows applications to adapt to the changing requirements. The model considers two or more participants to be involved in the conversation and thus enables most modern communication patterns, which is in contrast with the well-established two-participant model. Our contributions also include an implementation of a framework that realizes such communication methods and enables future innovation. We substantiate our claims by demonstrating case studies where we use the proposed abstractions to highlight the gains. We also show how the proposed model may be implemented in a backwards compatible manner, such that it does not break legacy applications, network stacks, or middleboxes in the network infrastructure. We also present use cases to substantiate our claims about backwards compatibility. This establishes that incremental evolution is possible. We highlight the benefits of context awareness in setting up complex communication constructs by presenting use cases and their evaluation. Finally, we show how the communication model may open the door for new and richer communication patterns. / PHD
90

Model based approach for context aware and adaptive user interface generation

Hanumansetty, Reena Gowri 26 August 2004 (has links)
User interface design and development for ubiquitous software applications is challenged by the presence of varying contexts. Context comprises of user'­s computing platform, the environment in which the user is interacting with the application and user characteristics which comprise of user's behavior during interaction and user preferences for interface display and interaction. We present a framework for adaptive user interface generation where adaptation occurs when context changes. This framework introduces three new concepts. First, formalization for representing context is introduced. Our design of context specification is unique since it reflects the association of context with level and nature of user interface adaptation. Secondly, user interface generation life cycle is studied and we define a context model on top of task model to introduce the contextual conditions into user interface generation process. Using the context model, user interface designer can specify contextual requirements and its effect on the user interface. Third, context aware adaptation of user interfaces is achieved by mapping context specifications to various levels of user interface generation life cycle. We designed a specification language called rule specification using which the user interface designer can specify the mapping. With the new design of context representation, context model, and rule specification, we demonstrate how changes in contexts adapts task model which in turn adapts the user interface. / Master of Science

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