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Accelerometer-based gesture recognition facilitates a complementary interaction modality for controlling mobile devices and home appliances. Using gestures for the task of home appliance control requires use of the same device and gestures by different persons, i.e. user independent gesture recognition. The practical application in small embedded low-resource devices also requires high computational performance. The user independent gesture recognition accuracy was evaluated with a set of eight gestures and seven users, with a total of 1120 gestures in the dataset. Twenty-state continuous HMM yielded an average of 96.9% user independent recognition accuracy, which was cross-validated by leaving one user in turn out of the training set. Continuous and discrete five-state HMM computational performances were compared with a reference test in a PC environment, indicating that discrete HMM is 20% faster. Computational performance of discrete five-state HMM was evaluated in an embedded hardware environment with a 104 MHz ARM-9 processor and Symbian OS. The average recognition time per gesture calculated from 1120 gesture repetitions was 8.3 ms. With this result, the computational performance difference between the compared methods is considered insignificant in terms of practical application. Continuous HMM is hence recommended as a preferred method due to its better suitability for a continuous-valued signal, and better recognition accuracy. The results suggest that, according to both evaluation criteria, HMM is feasible for practical user independent gesture control applications in mobile low-resource embedded environments.

A map can be a major advantage when exploring unfamiliar environments. With the proliferation of mobile devices, such as PDAs and even mobile phones, the tourist industry is currently exploring the potential of new presentation strategies that will maximize the promotional appeal of tourism in their region. Mobile devices are capable of guiding a tourist when he/she is exploring a city. These mobile devices offer the potential for providing relevant 3D information to enable tourists to locate themselves within the city, rapidly navigate around the unfamiliar environment and explore it interactively. However, the computational resources of current mobile technology prevents the display of full complex 3D content in real-time, and thus selective rendering techniques must be adopted to ensure the viewer is provided with the perceptually most important information at interactive rates.

This paper presents a series of experiments which help to identify key features of a scene for users to orientate themselves in that environment. Knowledge of these salient key features enable them to be provided to a user at a high quality while the remainder of the scene can be rendered in a much lower quality, saving significant bandwidth and computing power, without the user being perceptually aware of this difference in quality within the image.

The aim of this paper is to present a new mobile group decision making model to deal with heterogeneous information and changeable decision contexts. This model takes into account that experts have different backgrounds and knowledge levels, allowing to use different preference representations as fuzzy preference relations or linguistic preference relations with multigranular linguistic information. Furthermore, we allow to introduce some changes on the alternatives of the problem at every stage of the decision process. To do that: i) a mobile implementation is proposed to reduce the number of changes and ii) a mechanism to insert/remove alternatives is included in the model. Finally, our new decision model incorporates a feedback mechanism that sends recommendations to the experts in order to quickly obtain a high consensus level.

This paper examines the use of mobile devices for language learning. In particular we consider how different multimedia and interface modalities can be used to facilitate mobile language learning. The use of multimedia is considered within the context of Second Language Acquisition (SLA) and Computer Assisted Language Learning (CALL) theories. In particular, we examine the Interaction Framework, Schemata Theory, SLA Universal Grammar related theories and Multimedia Learning Theory. Two case studies serve to illuminate: the audio-based training of a system called MAC and the image-based training of another called PhotoStudy. We also suggest evaluation techniques that should be used to test the application of these theories to Mobile Assisted Language Learning (MALL).

In recent years point-and-shoot cameras were largely replaced by smartphones and tablets. For example, in the device chart of the Flickr photo sharing site the first four devices are smartphones. Eight megapixel sensors are already standard in high-end smartphones and Nokia released in 2012 a smartphone with a 41 megapixel sensor, aiming at product categories above point-and-shoot cameras. Since smartphones and tablets are easy to use and highly portable they are an easy choice for shooting images on the go. Therefore, image collections on the devices grow fast but the default grid-based image browsing interfaces are increasingly overwhelmed by the amount of images. They make it very difficult to find images fast and effortless. We therefore investigate the performance of new image browsing interfaces for smartphones and tablets, which utilize simple content-based sorting and 3D visualization to improve search time. In two user studies we compare a color sorted 3D-globe, 3D-ring, a zoomable image pane interface and a traditional grid-based image browsing interface. Our evaluations on tablets and smartphones show that especially 3D can reduce search time when there is enough screen space. On the other hand, it looses its advantage on smaller screens.

The reading experience on a mobile device can be influenced by many external elements that affect the viewing conditions. The user holding position, operating style, and the light conditions of the surroundings can all play a crucial factor in the legibility of the text. Furthermore, the user’s eye conditions may be an extra factor to consider when determining how to improve the reading experience. This study presents a context-aware application that adjusts the text font size based on the distance between the user and the device. The users select their preferred font size at certain distances in the calibration phase, accounting for individual preferences or their eye conditions, and the application uses the device’s front camera to calculate the distance in real time and adjust the font size accordingly. We present implementation details and challenges faced during development and how they were addressed. A two-part experiment ($n$ = 34) revealed that the application scored an excellent usability score while no differences were found between users with and without eye conditions, showing that both user groups find it equally usable. Additionally, initial results suggest that the visual landmarks used showed a promising start at addressing issues related to our approach.

This study proposes a customized and reusable component-based design framework based on the UML modeling process for intelligent home healthcare systems. All the proposed functional components are reusable, replaceable, and extensible for the system developers to implement customized home healthcare systems addressing different demands of patients and caregivers from healthcare monitoring aspects. The prototype design of the intelligent healthcare system based on these proposed components can provide the following features: (1) monitoring and recording videos of rehabilitation situations and patient behavior using multiple CCD cameras, which can be stored accordingly in an archive; (2) recording the patient's physiological data and corresponding treatment plan, which can be stored in an XML archiving database for caregivers' review; (3) automatically alerting patients to remind them of medication schedules or treatment plans, while recording the patient's treatment situations; (4) caregivers monitoring videos and physiological records of the patient's rehabilitation using handheld mobile devices via the Internet or wireless communication networks; and (5) caregivers and patients establishing alert mechanisms for the patients' physiological warning states. If the patient's physiological state suddenly deteriorates, the module would immediately alert caregivers by sending notification messages to their remote mobile devices or web browsers.

Cyber security is the term used to describe the processes and technologies designed to protect computers, networks, data and programs from unauthorized access, damage or attack. Many businesses pay lots of attention to security concerns. For these reasons this research has been undertaken. Ad-hoc networks are crucial enablers of next-generation communications. Such networks can be formed and reconfigured dynamically and they can be mobile, standalone or internetworked with other networks. Mobile Ad-hoc Networks (MANETs) are established by a group of autonomous nodes that communicate with each other by establishing a multi-hop radio network and maintaining connectivity in an infrastructure-less manner. The security of the connections between devices and networks is crucial. The important challenges of supporting multimedia applications in an ad-hoc network are the security issues. In this chapter, a new and efficient media-aware security framework will be designed for facilitating various multimedia applications in ad-hoc networks over the Internet.

An increasingly important topic in education is the use of video lectures. It is known that it has many advantages, for example, improving the accessibility of the education and in some aspects the interactivity of the learning process. Still, the accessibility is limited to those who have the right devices and internet access. In this paper we discuss the accessibility at developing countries such as Brazil. It was given a survey to 440 freshmen of the biggest brazilian engineering school in terms of number of students, the Escola Politecnica da Universidade de Sao Paulo. We worked on the results as a case study in order to try to expand the results, for example, to the case of a general developing country. Some of the results of the survey were that almost one third of the students watches video lectures once a week, more than 80% of the students watch it to have a better understanding of the subject and the biggest part of the students are watching through Youtube. Finally, this study suggests that in order to improve the accessibility it is important to invest in services related to smartphones and Youtube. We noticed that it is important to make similar studies at other universities because of the socioeconomic bias found at the case studied.