Providing user context for mobile and social networking applications

The processing capabilities of mobile devices coupled with portable and wearable sensors provide the basis for new context-aware services and applications tailored to the user environment and daily activities. In this article, we describe the approach developed within the UPCASE project, which makes use of sensors available in the mobile device as well as sensors externally connected via Bluetooth to provide user contexts. We describe the system architecture from sensor data acquisition to feature extraction, context inference and the publication of context information in web-centered servers that support well-known social networking services. In the current prototype, context inference is based on decision trees to learn and to identify contexts dynamically at run-time, but the middleware allows the integration of different inference engines if necessary. Experimental results in a real-world setting suggest that the proposed solution is a promising approach to provide user context to local mobile applications as well as to network-level applications such as social networking services.     

Status and trends of mobile-health applications for iOS devices: A developer's perspective

Modern smart mobile devices offer media-rich and context-aware features that are highly useful for electronic-health (e-health) applications. It is therefore not surprising that these devices have gained acceptance as target devices for e-health applications, turning them into m-health (mobile-health) apps. In particular, many e-health application developers have chosen Apple's iOS mobile devices such as iPad, iPhone, or iPod Touch as the target device to provide more convenient and richer user experience, as evidenced by the rapidly increasing number of m-health apps in Apple's App Store. In this paper, the top two hundred of such apps from the App Store were examined from a developer's perspective to provide a focused overview of the status and trends of iOS m-health apps and an analysis of related technology, architecture, and user interface design issues. The top 200 apps were classified into different groups according to their purposes, functions, and user satisfaction. It was shown that although the biggest group of apps was medical information reference apps that were delivered from or related to medical articles, websites, or journals, mobile users disproportionally favored tracking tools. It was clear that m-health apps still had plenty of room to grow to take full advantage of unique mobile platform features and truly fulfill their potential. In particular, introduction of two- or three-dimensional visualization and context-awareness could further enhance m-health app's usability and utility. This paper aims to serve as a reference point and guide for developers and practitioners interested in using iOS as a platform for m-health applications, particular from the technical point of view.     

Evaluating the benefits of multimodal interface design for CoMPASS—a mobile GIS

The context of mobility raises many issues for geospatial applications providing location-based services. Mobile device limitations, such as small user interface footprint and pen input whilst in motion, result in information overload on such devices and interfaces which are difficult to navigate and interact with. This has become a major issue as mobile GIS applications are now being used by a wide group of users, including novice users such as tourists, for whom it is essential to provide easy-to-use applications. Despite this, comparatively little research has been conducted to address the mobility problem. We are particularly concerned with the limited interaction techniques available to users of mobile GIS which play a primary role in contributing to the complexity of using such an application whilst mobile. As such, our research focuses on multimodal interfaces as a means to present users with a wider choice of modalities for interacting with mobile GIS applications. Multimodal interaction is particularly advantageous in a mobile context, enabling users of location-based applications to choose the mode of input that best suits their current task and location. The focus of this article concerns a comprehensive user study which demonstrates the benefits of multimodal interfaces for mobile geospatial applications.     

Exploring the benefits of the combination of a software architecture analysis and a usability evaluation of a mobile application

Designing easy to use mobile applications is a difficult task. In order to optimize the development of a usable mobile application, it is necessary to consider the mobile usage context for the design and the evaluation of the user-system interaction of a mobile application. In our research we designed a method that aligns the inspection method “Software ArchitecTure analysis of Usability Requirements realizatioN” SATURN and a mobile usability evaluation in the form of a user test. We propose to use mobile context factors and thus requirements as a common basis for both inspection and user test. After conducting both analysis and user test, the results described as usability problems are mapped and discussed. The mobile context factors identified define and describe the usage context of a mobile application. We exemplify and apply our approach in a case study. This allows us to show how our method can be used to identify more usability problems than with each method separately. Additionally, we could confirm the validity and identified the severity of usability problems found by both methods. Our work presents how a combination of both methods allows to address usability issues in a more holistic way. We argue that the increased quantity and quality of results can lead to a reduction of the number of iterations required in early stages of an iterative software development process.     

Building ubiquitous QoC-aware applications through model-driven software engineering

As every-day mobile devices can easily be equipped with multiple sensing capabilities, ubiquitous applications are expected to exploit the richness of the context information that can be collected by these devices in order to provide the service that is the most appropriate to the situation of the user. However, the design and implementation of such context-aware ubiquitous appplications remain challenging as there exist very few models and tools to guide application designers and developers in mastering the complexity of context information. This becomes even more crucial as context is by nature imperfect. One way to address this issue is to associate to context information meta-data representing its quality. We propose a generic and extensible design process for context-aware applications taking into account the quality of context (QoC). We demonstrate its use on a prototype application for sending flash sale offers to mobile users. We present extensive performance results in terms of memory and processing time of both elementary context management operations and the whole context policy implementing the Flash sale application. The cost of adding QoC management is also measured and appears to be limited to a few milliseconds. We show that a context policy with 120 QoC-aware nodes can be processed in less than 100 ms on a mobile phone. Moreover, a policy of almost 3000 nodes can be instantiated before exhausting the resources of the phone. This enables very rich application scenarios enhancing the user experience and will favor the development of new ubiquitous applications.     

User needs for location-aware mobile services

Mobile contexts of use vary a lot, and may even be continuously changing during use. The context is much more than location, but its other elements are still difficult to identify or measure. Location information is becoming an integral part of different mobile devices. Current mobile services can be enhanced with location-aware features, thus providing the user with a smooth transition towards context-aware services. Potential application fields can be found in areas such as travel information, shopping, entertainment, event information and different mobile professions. This paper studies location-aware mobile services from the user's point of view. The paper draws conclusions about key issues related to user needs, based on user interviews, laboratory and field evaluations with users, and expert evaluations of location-aware services. The user needs are presented under five main themes: topical and comprehensive contents, smooth user interaction, personal and user-generated contents, seamless service entities and privacy issues.     

A proxy architecture for collaborative media streaming

Streaming media from the Internet is a successful application for end-users. With the upcoming success of mobile devices and home networking environments, cooperation among users will become more important in the future. To achieve such cooperation, explicit middleware standards have been defined. On the other hand, Internet conferencing applications do not handle collaborative streaming sessions with individual control for each user. We propose a new concept for cooperation exemplary for collaborative media streaming using IETF multimedia session control protocols together with a proxy architecture. This concept enables both synchronization among clients and flexible control to individual users.     

Design and implementation of a smart system for personalization and accurate selection of mobile services

Wireless mobile services are computing applications that run on handheld wireless devices. Such applications must work within the daunting constraints of the devices, which include memory, processing power, input capabilities, and size of display. It is therefore important that mobile services take into account the user’s context, optimize resource usage, and minimize input effort imposed on the user. In this paper, we present the design and implementation of a smart agent-enabled system for personalizing wireless mobile services and advertisements for Java 2 Micro Edition (J2ME) or Java ME, and Wireless Application Protocol (WAP) enabled devices. We use software agents for context filtering because such autonomous software entities have characteristics that can benefit mobile devices and the wireless environment, and the Composite Capability/Preference Profiles (CC/PP) standard for defining profiles for user preferences and device capabilities. The system incorporates the use of artificial neural networks to adaptively and iteratively learn to select the best available service based on contextual information. The system is evaluated using practical operating scenarios, as well as empirical data and results show an 87% success rate in the selection of the best available service.     

Utilizing a Bluetooth remote lock system for a smartphone

With the advent of mobile devices and the convergence of wireless technologies and the Internet, both the content and the quality of research in this field are subject to regular change. A variety of state-of-the-art computing devices that are compatible with each other have been produced. These devices have the ability to interact with people. This is also known as pervasive computing. Particularly, as smartphones have recently become one of the most popular devices worldwide, various convenient applications are being released. Smartphones available today not only provide the ordinary internal processes such as dialing or receiving phone calls, sending text messages, and doing mobile banking, but also increasingly control various other devices that are part of our daily lives. In effect, this means that through smartphone applications, we can remotely control a variety of external devices such as televisions, projectors for presentations, computers, and even cars. The research in this paper is based on the evolving technological possibilities of using smartphone applications to control external devices. This paper presents the design and implementation of a remote lock system using wireless communication on a smartphone. In this context, remote lock system refers to a lock system that can be controlled remotely by a dedicated Android application. Every smartphone is equipped with Bluetooth which makes this technology possible. The application proposed in this paper uses the existing Bluetooth function on Android smartphones to open and manage locks. The users’ lock information can be stored and managed in real time in the database via a server that is built and managed by a server manager. Even if users forget the password of the lock, our proposed lock system can guide them to retrieve it easily, and a user manual is included to help users navigate the system. This system also provides a variety of management functions such as adding, deleting, modifying, and purchasing the user’s own locks.     

User satisfaction aware routing and energy modeling of polymorphic network on chip architecture

In mobile devices, multiple applications contend for limited resources in the underlying embedded system framework. Application resource requirements in mobile systems vary by computation needs, energy consumption and user interaction frequency. Quality of service (QoS) is the predominant metric of choice to manage resources among contending applications. Resource allocation policies to support static QoS for applications do not reflect the changing demands of the user in contemporary network on chip (NoC) based embedded architectures. User satisfaction with the user interactions and user interface design ought to be the primary design driver. Some recent research has integrated a saturating, non-linear user satisfaction function in the application thread scheduler. The application and operating system level user satisfaction research assumes that the throughput of inter-thread edges is limited only by the computational constraints of the nodes. With NoC, however, NoC resource allocation policies play an important role in determining the inter-thread communication flow’s throughput and the resulting application level user satisfaction. In this paper, we filter down the user satisfaction from an application layer attribute to a router level attribute to improve the resource and energy utilization for routing in order to leverage the user satisfaction at the application and system level. We demonstrate that this technique improves the user satisfaction of audio (MP3) application by 10% while maintaining the user satisfaction of video (MPEG-2) application. Experiments also show that a fixed energy source can be extended for an average of 18% of the time using the NoC user satisfaction based energy optimization proposed in this research.     

CARISMA: context-aware reflective middleware system for mobile applications

Mobile devices, such as mobile phones and personal digital assistants, have gained wide-spread popularity. These devices will increasingly be networked, thus enabling the construction of distributed applications that have to adapt to changes in context, such as variations in network bandwidth, battery power, connectivity, reachability of services and hosts, etc. In this paper, we describe CARISMA, a mobile computing middleware which exploits the principle of reflection to enhance the construction of adaptive and context-aware mobile applications. The middleware provides software engineers with primitives to describe how context changes should be handled using policies. These policies may conflict. We classify the different types of conflicts that may arise in mobile computing and argue that conflicts cannot be resolved statically at the time applications are designed, but, rather, need to be resolved at execution time. We demonstrate a method by which policy conflicts can be handled; this method uses a microeconomic approach that relies on a particular type of sealed-bid auction. We describe how this method is implemented in the CARISMA middleware architecture and sketch a distributed context-aware application for mobile devices to illustrate how the method works in practice. We show, by way of a systematic performance evaluation, that conflict resolution does not imply undue overheads, before comparing our research to related work and concluding the paper.     

Context-aware recommendations through context and activity recognition in a mobile environment

The mobile Internet introduces new opportunities to gain insight in the user’s environment, behavior, and activity. This contextual information can be used as an additional information source to improve traditional recommendation algorithms. This paper describes a framework to detect the current context and activity of the user by analyzing data retrieved from different sensors available on mobile devices. The framework can easily be extended to detect custom activities and is built in a generic way to ensure easy integration with other applications. On top of this framework, a recommender system is built to provide users a personalized content offer, consisting of relevant information such as points-of-interest, train schedules, and touristic info, based on the user’s current context. An evaluation of the recommender system and the underlying context recognition framework shows that power consumption and data traffic is still within an acceptable range. Users who tested the recommender system via the mobile application confirmed the usability and liked to use it. The recommendations are assessed as effective and help them to discover new places and interesting information.     

Context-aware mobile service for routing the fastest subway path

The rapid growth of the IT industry during the last few decades has increased demands on mobile devices such as PDAs, cellular phones, and GPS navigation systems. With emerging concepts of context-aware computing, the mobile devices can provide mobile users with timely information by using not only common knowledge but also environmental context such as current time and location. Lately, the context-aware applications have been actively investigated and have been contributed to numerous application areas such as real-time electronic catalogues and navigation systems for tourists. In this paper, we propose a new context-aware application for finding the fastest subway route. We have developed the proposed application as an implemented system named Optimize Your Time System (OYT System, for short). A terminal device of the OYT System is equipped with a GPS receiver and the system’s server contains a timetable of all trains in a target subway system. On perceiving users’ context such as current time and location automatically from GPS, the OYT System can display the optimal route which takes the shortest time for the user to reach the specified destination. In this paper, we present details of the OYT System and some experimental examples.     

基于服务的移动用户界面软件架构研究*

为了解决传统的用户界面软件架构在移动应用中的种种缺陷,提出了一种基于服务的移动用户界面软件架构IMA(interface-manager-application),使移动设备受益于面向服务范型。IMA通过提供简单且个性化的服务版本使后台服务适应移动能力,从而集成化地解决了移动设备的资源受限性、间歇性连接和个性化问题。通过AndroidIDB的原型开发验证了该架构的可行性和有效性。     

An efficient model-based methodology for developing device-independent mobile applications

Current methodologies for developing mobile applications are mostly based on the application programming interfaces (APIs) offered by the native platform. Hence, most solutions are characterized by a low portability and/or reusability. In this paper, we propose a novel methodology based on a declarative and device-independent approach for developing event-driven mobile applications. The methodology relies on: (i) an abstract mobile device based on the user interface markup language; (ii) a content adaptation mechanism based on user preferences; (iii) a context adaptation mechanism based on a standardized context of delivery; (iv) a uniform set of client-side APIs based on an interface object model; (v) an efficient transformational model.More specifically, in the design phase, the application is modeled as platform-independent on the abstract mobile device. In the execution phase, the application is automatically tailored to the specific platform on the basis of the content and context adaptation mechanisms. We describe the analysis, design and implementation of a framework, called MODIF, which supports the proposed methodology, and show its application to the development of both business and consumer real-world applications on Apple iPhone? and Google Android? mobile devices. Finally, we discuss how the experience of using MODIF highlights the quality of the methodology in terms of automation of the lifecycle, expressiveness and readability of the representation, efficiency of the compilation/interpretation, fast learning curve and predictability.     

Augmented reality agents for user interface adaptation

Most augmented reality (AR) applications are primarily concerned with letting a user browse a 3D virtual world registered with the real world. More advanced AR interfaces let the user interact with the mixed environment, but the virtual part is typically rather finite and deterministic. In contrast, autonomous behavior is often desirable in ubiquitous computing (Ubicomp), which requires the computers embedded into the environment to adapt to context and situation without explicit user intervention. We present an AR framework that is enhanced by typical Ubicomp features by dynamically and proactively exploiting previously unknown applications and hardware devices, and adapting the appearance of the user interface to persistently stored and accumulated user preferences. Our framework explores proactive computing, multi‐user interface adaptation, and user interface migration. We employ mobile and autonomous agents embodied by real and virtual objects as an interface and interaction metaphor, where agent bodies are able to opportunistically migrate between multiple AR applications and computing platforms to best match the needs of the current application context. We present two pilot applications to illustrate design concepts. Copyright © 2007 John Wiley & Sons, Ltd.     

TruBeRepec: a trust-behavior-based reputation and recommender system for mobile applications

Mobile applications are software packages that can be installed and executed in a mobile device. Which mobile application is trustworthy for a user to purchase, download, install, execute or recommend becomes a crucial issue that impacts its final success. This paper proposes TruBeRepec, a trust-behavior-based reputation and recommender system for mobile applications. We explore a model of trust behavior for mobile applications based on the result of a large-scale user survey. We further develop a number of algorithms that are used to evaluate individual user’s trust in a mobile application through trust behavior observation, generate the application’s reputation by aggregating individual trust and provide application recommendations based on the correlation of trust behaviors. We show the practical significance of TruBeRepec through simulations and analysis with regard to effectiveness, robustness, and usability, as well as privacy.     

A comparison of mobile form controls for different tasks

Web forms are the design tools that are used for gathering inputs from users in interactive applications. These forms are mainly developed for desktop applications, and transferring them directly to a mobile context did not work well most of the time. Since user experience with mobile devices is different from with desktop computers, the efficiency and accuracy of form controls (buttons, text boxes, drop-down boxes, radio buttons, etc.) in the user interface is essential.In the scope of this research, a user study was conducted to compare the efficiency, effectiveness, and user satisfaction of mobile form controls. In the user study, an experiment was set up to compare four different form controls that were frequently used in mobile web applications, considering variation by task type and size of data set, in the context of two different touch-based smartphones, one running the iOS operating system and the other running the Android operating system. The form controls in the experiment were button, radio button/switch, spinner/picker, and text field. The task types were mutually exclusive selection, non-mutually exclusive selection, and set-a-value. Set sizes were designated as either small set size for less than 5 items or large set size for more than 5 items. There were 30 participants in the study. The task performance, accuracy, and satisfaction levels of the participants, as well as their perceived and actual performances, were recorded. The results showed that the button was fastest for small-set, mutually exclusive tasks while the spinner was fastest for large sets. In addition, it was found that the radio button/switch was the most effective controller for the non-mutually exclusive tasks. Based on the results of the experiment and analysis of the existing literature, five key issues for these form controls were identified to guide application developers in mobile form design: visibility, data set size, task type, users' experience level with a system, and screen layout.     

A query-oriented XML text summarization for mobile devices

Extensible Markup Language (XML) is a simple, flexible text format derived from SGML, which is originally designed to support large-scale electronic publishing. Nowadays XML plays a fundamental role in the exchange of a wide variety of data on the Web. As XML allows designers to create their own customized tags, enables the definition, transmission, validation, and interpretation of data between applications, devices and organizations, lots of works in soft computing employ XML to take control and responsibility for the information, such as fuzzy markup language, and accordingly there are lots of XML-based data or documents. However, most of mobile and interactive ubiquitous multimedia devices have restricted hardware such as CPU, memory, and display screen. So, it is essential to compress an XML document/element collection to a brief summary before it is delivered to the user according to his/her information need. Query-oriented XML text summarization aims to provide users a brief and readable substitution of the original retrieved documents/elements according to the user’s query, which can relieve users’ reading burden effectively. We propose a query-oriented XML summarization system QXMLSum, which extracts sentences and combines them as a summary based on three kinds of features: user’s queries, the content of XML documents/elements, and the structure of XML documents/elements. Experiments on the IEEE-CS datasets used in Initiative for the Evaluation of XML Retrieval show that the query-oriented XML summary generated by QXMLSum is competitive.     

Preprocessing techniques for context recognition from accelerometer data

The ubiquity of communication devices such as smartphones has led to the emergence of context-aware services that are able to respond to specific user activities or contexts. These services allow communication providers to develop new, added-value services for a wide range of applications such as social networking, elderly care and near-emergency early warning systems. At the core of these services is the ability to detect specific physical settings or the context a user is in, using either internal or external sensors. For example, using built-in accelerometers, it is possible to determine whether a user is walking or running at a specific time of day. By correlating this knowledge with GPS data, it is possible to provide specific information services to users with similar daily routines. This article presents a survey of the techniques for extracting this activity information from raw accelerometer data. The techniques that can be implemented in mobile devices range from classical signal processing techniques such as FFT to contemporary string-based methods. We present experimental results to compare and evaluate the accuracy of the various techniques using real data sets collected from daily activities.