Sketch recognition allows computers to understand and model hand drawn sketches and diagrams. Traditionally sketch recognition systems required a pen based PC interface, but powerful mobile devices such as tablets and smartphones can provide a new platform for sketch recognition systems. We describe a new sketch recognition library, Strontium (SrL) that combines several existing sketch recognition libraries modified to run on both personal computers and on the Android platform. We analyzed the recognition speed and accuracy implications of performing low-level shape recognition on smartphones with touch screens. We found that there is a large gap in recognition speed on mobile devices between recognizing simple shapes and more complex ones, suggesting that mobile sketch interface designers limit the complexity of their sketch domains. We also found that a low sampling rate on mobile devices can affect recognition accuracy of complex and curved shapes. Despite this, we found no evidence to suggest that using a finger as an input implement leads to a decrease in simple shape recognition accuracy. These results show that the same geometric shape recognizers developed for pen applications can be used in mobile applications, provided that developers keep shape domains simple and ensure that input sampling rate is kept as high as possible.

Mobile devices have evolved over the years from resource constrained devices that supported only the most basic tasks to powerful handheld computing devices. However, the most significant step in the evolution of mobile devices was the introduction of wireless connectivity which enabled them to host applications that require internet connectivity such as email, web browsers and maybe most importantly smart/rich clients. Being able to host smart clients allows the users of mobile devices to seamlessly access the Information Technology (IT) resources of their organizations. <p>One increasingly popular way of enabling access to IT resources is by using Web Services (WS). This trend has been aided by the rapid availability of WS packages/tools, most notably the efforts of the Apache group and Integrated Development Environment (IDE) vendors. But the widespread use of WS raises questions for users of mobile devices such as laptops or PDAs; how and if they can participate in WS. Unlike their wired counterparts (desktop computers and servers) they rely on a wireless network that is characterized by low bandwidth and unreliable connectivity.<p>The aim of this thesis is to enable mobile devices to host Web Services consumers. It introduces a Model-Driven Dual Caching (MDDC) approach to overcome problems arising from temporarily loss of connectivity and fluctuations in bandwidth.

Mobile devices are increasingly being used to access Web content but lack the resources for proper presentation to the user. To address this problem, content is typically customized to be more suitable for a mobile environment. Automatic customization of web content is a challenging problem because fine-grain adaptation often depends on both the relevance of individual objects on a web page, as well as the context of access (e.g., screen size of device being used, network connectivity, location, etc.). We present Usage-aware Interactive Content Adaptation, an adaptation technique that allows a user who is unsatisfied with the system’s adaptation decision to take control of the adaptation process and make changes until the content is suitably adapted for her purposes. The adaptation system learns from the user’s modifications and adjusts its prediction for future accesses by other users. With this approach, users are empowered to correct bad adaptation decisions made by the system without being overly burdened. We applied the technique in two domains: adapting the quality of images to reduce download times and save energy and bandwidth, and customizing the layout of images to improve the utilization of screen real-estate. The work was evaluated through a series of user studies, and the results show that user feedback can be effectively used to provide appropriate customizations (i) for objects with varying relevance, (ii) when context affects the users adaptation requirements, and (iii) when the same content can be used for multiple purposes by different users.

The use of mobile devices is increasing due to the constant development of more advanced and appealing applications and computing features. However, these new features are very power hungry leading to short battery lifetimes. Research shows that a major reason for fast battery depletion is the excessive and inefficient use of the wireless interfaces. This thesis studies how we can attempt to increase the battery lifetime of the devices without having to sacrifice the usage of these advanced features in some applications. The thesis focuses on adapting the traffic pattern characteristics of mobile communication using a widespread wireless communication technology like 3G. Traffic pattern adaptation is performed at packet level in kernel space in Android. The data transfers are scheduled with the knowledge of the energy consumption characteristics of 3G. The performed measurements indicate that our solution can provide energy savings ranging from 7% to 59%. This work confirms that 3G conscious scheduling of network traffic reduces energy consumption, and that, both applications and energy saving libraries are potential directions to be further studied.

Mobile devices have evolved over the years from resource constrained devices that supported only the most basic tasks to powerful handheld computing devices. However, the most significant step in the evolution of mobile devices was the introduction of wireless connectivity which enabled them to host applications that require internet connectivity such as email, web browsers and maybe most importantly smart/rich clients. Being able to host smart clients allows the users of mobile devices to seamlessly access the Information Technology (IT) resources of their organizations. <p>One increasingly popular way of enabling access to IT resources is by using Web Services (WS). This trend has been aided by the rapid availability of WS packages/tools, most notably the efforts of the Apache group and Integrated Development Environment (IDE) vendors. But the widespread use of WS raises questions for users of mobile devices such as laptops or PDAs; how and if they can participate in WS. Unlike their wired counterparts (desktop computers and servers) they rely on a wireless network that is characterized by low bandwidth and unreliable connectivity.<p>The aim of this thesis is to enable mobile devices to host Web Services consumers. It introduces a Model-Driven Dual Caching (MDDC) approach to overcome problems arising from temporarily loss of connectivity and fluctuations in bandwidth.

<p>Advances in mobile hardware and operating systems have made mobile a first-class development platform. Activities such as web browsing, casual game play, media playback, and document reading are now as common on mobile devices as on full-sized desktop systems. However, developers are still constrained by the inherent resource limitations of mobile devices. Unlike desktop systems, mobile devices must sacrifice performance to accomodate smaller form factors and battery-backed operation. Opportunistic offloading of computation from a mobile device to remote server infrastructure (i.e., "code offload") offers a promising way to overcome these constraints and to expand the set of applications</p><p>(i.e., "apps") that can run on devices.</p><p>Deciding to offload requires a careful consideration of the costs and benefits of a range of possible program partitions. This cost-benefit analysis depends on external factors, such as network conditions and the resources availability, as well as internal app properties, such as component dependencies, data representations, and code complexity. Thus, benefiting from offload requires some assistance from developers, but requiring developers to adopt arcane or unnatural programming models will hinder adoption of regardless of the potential benefits.</p><p>In this dissertation we characterize two frameworks that reduce the amount of developer effort required to improve the performance of mobile apps through code offload. The first, MAUI, is designed for computationally intensive general-purpose apps such as speech</p><p>and facial recognition. The second, Kahawai, is designed for graphics-intensive apps like fast-action video games.</p><p>MAUI continuously monitors the device, network, and app, and uses its measurements to compute an energy-efficient program partition. MAUI reduces the burden on developers by taking advantage of core features of the managed code environments common to mobile</p><p>platforms: code portability, serialization, reflection, and type safety. These features allows MAUI to automatically instrument and potentially offload methods that the developer has tagged as suitable for offload. MAUI is particularly effective on applications composed by operations whose computational cost is large compared to the transfer cost of their input parameters and their output results.</p><p>Kahawai is designed for graphics-intensive apps such as console-style games and takes advantage of two features of today's mobile gaming platforms: capable mobile GPUs and reusable game engines. Even though today's mobile devices cannot duplicate the sophisticated graphical detail provided by gaming consoles and high-end desktop GPUs, devices have seen rapid improvements in their GPU processing capabilities. Kahawai leverages a device's GPU to provide collaborative rendering. Collaborative rendering relies on a mobile GPU to generate low-fidelity output, which when combined with server-side GPU output allows a mobile device to display a high-fidelity result. The benefits of collaborative rendering are substantial: mobile clients can experience high-quality graphical output using relatively little bandwidth. Fortunately, because most modern games are built on top of reusable game engines, developers only have to identify the sources of non-determinism</p><p>in the game logic to take advantage collaborative rendering.</p><p>Together, MAUI and Kahawai demonstrate that code offload can provide substantial benefits for mobile apps without overburdening app developers.</p> / Dissertation

Authentication protocols are very common mechanisms to confirm the legitimacy of someone’s or something’s identity in digital and physical systems. This thesis presents a new and robust authentication method based on users’ multiple devices. Due to the popularity of mobile devices, users are becoming more likely to have more than one device (e.g., smartwatch, smartphone, laptop, tablet, smart-car, smart-ring, etc.). The authentication system presented here takes advantage of these multiple devices to implement authentication mechanisms. In particular, the system requires the devices to collaborate with each other in order for the authentication to succeed. This new authentication protocol is robust against theft-based attacks on single device; an attacker would need to steal multiple devices in order to compromise the authentication system. The new authentication protocol comprises an authenticator and at least two user devices, where the user devices are associated with each other. To perform an authentication on a user device, the user needs to respond a challenge by using his/her associated device. After describing how this authentication protocol works, this thesis will discuss three different versions of the protocol that have been implemented. In the first implementation, the authentication process is performed by using two smartphones. Also, as a challenge, a QR code is used. In the second implementation, instead of using a QR code, NFC technology is used for challenge transmission. In the last implementation, the usability with different platforms is exposed. Instead of using smartphones, a laptop computer and a smartphone combination is used. Furthermore, the authentication protocol has been verified by using an automated protocol-verification tool to check whether the protocol satisfies authenticity and secrecy properties. Finally, these implementations are tested and analyzed to demonstrate the performance variations over different versions of the protocol.

Research paper / The use of Mobile technologies in organisation including institution of higher education has increased significantly in recent years. In institution of higher education, the focuses have been on its use for teaching and learning. Due to the flexibility and easy accessibility, learners and educators are increasingly depending mobile technologies for their academic activities. The development of mobile technology has resulted in shifting the academic environment from traditional to mobile learning settings. This paper focused on the possible implications of mobile devices on teaching and learning. The qualitative case study approach was employed in the study. Based on the finding from the analysis of the empirical data, a Framework was developed. The Framework could be employed to address the implications in the drive to enhance the services of academic library. Mobile learning has a lot of potential for quick and wide reaching out to the geographically wide spread of learners. The paper helps to gain a deeper understanding of the impact of mobile technology in providing services in the library of academic institutions.

With the development of the computer networks, mainly the Internet, it became easier to develop applications where the execution is shared between a local computer, the Client, and one located on the other side of the network communication channel, the Server. The hardware advancements in the recent years made it possible to display 3D graphics (games, map navigation, virtual worlds) on mobile devices. However, executing these complex applications on the client terminal is not possible without reducing the quality of the displayed graphics or lowering its processing requirements. Different solutions have already been proposed in academic publications; however none of them satisfies all requirements. The objective of this thesis is to propose an alternative solution for a new client-server architecture where the connectedness of the mobile devices is fully exploited. Several main requirements are addressed: - Minimize the network traffic, - Reduce the required computational power on the terminal, and - Preserve the user experience compared with local execution. First a formal framework is designed that can effectively define and model distributed applications for 3D graphics. Then a model of new architecture is presented, that overcomes the disadvantages of the architectures presented in the state of the art. The core of the architecture is the MPEG-4 standard, which is used to transfer the data between the server and the client in a compressed manner. The last part of explores the design of architectures optimized for running on mobile devices. The design of the new client-server architecture is validated by implementing a game and running simulations.

Mobility and using smartphones and tablets as replacement of laptops are getting to be increasingly vital for enterprises and accordingly bring new concerns from different perspective for both companies and individuals. To achieve enterprise mobility companies needs to ensure that the mobile equipment are always connected, complies with security policy in a safe and protected path toward being productivity and efficiency. To approach these purposes Mobile Device Management (MDM) was created few years back in order to not only secure enterprises information but additionally manage user’s activities and equipment. However there is no general methodology to define criteria weight for these systems and rather depends on different enterprise policy. One primary issue here is availability of many MDM solutions in market and several difficulties to compare them together and meanwhile most of comparison documents limited based on white papers of providers which mostly designed for commercial market purposes. This thesis will come up with a list of important properties for MDM solutions and evaluate several of solutions as well as categorizing all available criteria in this area. Second part of thesis is a case study of choosing proper MDM solution for two different scenarios and give recommendations on what products to utilize relying upon what sort of association you have. In order to achieve this, strong analytical methods are required to compare existing services and sharper eye from security perspective toward the applications.