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Activity-Oriented Context Adaptation in Mobile Applications
Abstract
Although usability of mobile devices increases steadily, use of mobile applications is still inconvenient. Adapting application behavior and functionality to the user's current needs is a promising approach to compensate for limited input capabilities. Despite great effort in research, smart adaptable applications are still rare. With our approach, we build upon existing works and extend them with the notion of activity context. Activities are one of the most basic elements of context and are well suited to determine the relevance of context entities in a given situation. Such information can be used to realize more intelligent suggestion mechanisms for input elements in mobile applications. The feasibility of our approach has been proven by a prototype implementation of our Activity Awareness Architecture for the Android platform providing activity context for mobile applications and a context-aware calendar on top of it demonstrating the usefulness of activity context. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering.
... We learn from the comparison that the most significant difference between AocML and other approaches is the application domain. Besides PAOC [3] , some other existing researches (e.g., [32][33]) also consider the development based on activities. Furthermore, some efforts (e.g., Egospace [34] ) separate the development of infrastructure and application requirements. ...
Activity-oriented context-aware (AOCA) applications are representative in pervasive computing. These applications recognize daily-life human activities, perceive the environment status related to the activities, and react to ensure the smooth performance of the activities. Existing research proposed a specific light-weight, incremental method to support the development of such applications; however it is not easy to learn and use. This paper aims to facilitate the development of such applications and improve the productivity of developers. We propose AocML, a textual domain-specific language which provides a high-level abstraction of AOCA applications. Specifically, we first show the software model of AOCA applications and the abstract syntax of AocML. Then, we introduce the concrete syntax of AocML. We also implement the tools for AocML, including the development environment as well as the generation of Java code and ontology specification. Moreover, we use a case study and evaluation to demonstrate the advantages of AocML.
Context-aware system is an emerging research area in recent years. Context plays an important role in these systems. In most existing work, context is treated as all relative elements in the environment of an application, and the scope of context is predefined by the developers during the development. However, it is difficult to analyze, specify, and organize everything in the environment accurately and completely; and even when it is possible, the developed applications are difficult to extend or modify as the requests for environment may change over time. In this paper, we focus on activity-oriented context-aware (AOCA) applications where the requests for environment are highly dependent on user activities, and propose a programming framework for developing AOCA applications. In particular, we first present a concept model for describing the notions of activity-oriented context. Next, based on the concept model, we describe the details of the programming framework as well as a development tool. Moreover, we provide a platform to support the runtime of AOCA applications, and demonstrate the advantages of our programming framework through experimental evaluations.
Context-awareness is one of the major research areas of pervasive computing. Context plays an important role in such systems. In most existing work, researchers view context as all elements in the environment of an application and use it just as passive data. This kind of context is unfavorable to the quality of context-aware applications. During the development of applications, it is difficult for developers to analyze, specify and organize everything in the environment accurately and completely. This kind of application is hard to be extended or modified when the requirements on environment change in the future. In the runtime, these applications have to deal with all the environment events even though they have nothing to do with the current user activity which should be served. In this paper, we propose an activity-oriented context (AOC) approach in order to improve the quality of context-aware applications. We give the AOC concept model and a context-aware software model with proactive activity-oriented context entity. We implement a platform to support context-awareness with activity-oriented context (PAOC). We also present a case study and an evaluation to demonstrate the usability and performance of our approach.
We envision a future where people's living spaces are interactive and programmable. Users interact with their offices, homes, cars, malls and airports to request information, benefit from the resources available, and configure the habitat's behavior. Data and tasks are always accessible and are mapped dynamically to convenient resources present in the current location. Users may extend the habitat with personal devices that seamlessly integrate with the environment. Such user-oriented interactive environments may require a novel software infrastructure to operate their resources, sense context properties, and assist in the development and execution of applications. In this article, we present an experimental middleware infrastructure called Gaia that we have used to prototype the resource management of and provide the user- oriented interfaces for such physical spaces populated with network-enabled computing resources. To limit the scope of our research, we focus on physical spaces used for teaching; classrooms, offices, and lecture rooms. The system described in this paper is derived from a series of experiments starting in 1996. We show how, by applying the concepts of a conventional operating system to middleware, we can manage the resources, devices and distributed objects in a room, building, or physical space, how a distributed extension of the model-view-controller that is use in personal computers simplifies and structures practical applications for these environments, and how, by driving context-sensitivity into its data storage mechanisms, the system can help satisfy the requirements for user-centricity and mobility.
We present an architecture that offers a set of generic services for building context-aware mobile applications. We present two realized prototypes that recognize user’s context, learn his routines, use context information to constrain service discovery as well as to find relevant information, and manage connectivity on the basis of the given policy. Further, the user interfaces and applications are separated using a script language, and video message delivery is controlled based on presence information. We are not aware of any other prototypes offering equally wide context-aware functionality.
Context awareness enables applications to adapt themselves to their computing environment in order to better suit the needs of the user and the tasks. This paper describes a general middleware infrastructure for context collection and dissemination, realized as a Context Service. By way of two example applications, this paper also illustrates how context information provided by our context service can be exploited to enhance the user experience. These two applications are built upon the abstraction provided by the Context Service and thus help validate the design of this service. The first application, a Notification Dispatcher, uses context to route messages to the most appropriate communication device for a recipient. The second application, a context-aware content distribution system, uses context to predict users' access to web content, and uses these predictions to pre-process and pre-distribute content in order to reduce the access latency.
One of the cornerstones of any intelligent entity is the ability to understand how occurrences in the surrounding world influence its own behaviour. Different states, or situations, in its environment should be taken into account when reasoning or acting. When dealing with different situations, context is the key element used to infer possible actions and information needs. The activities of the perceiving agent and other entities are arguably one of the most important features of a situation; this is equally true whether the agent is artificial or not.
This work proposes the use of Activity Theory to first model context and further on populate the model for assessing situations in a pervasive computing environment. Through the socio-technical perspective given by Activity Theory, the knowledge intensive context model, utilised in our ambient intelligent system, is designed.
Context-awareness is one of the drivers of the ubiquitous computing paradigm, whereas a well designed model is a key accessor to the context in any context-aware system. This paper provides a survey of the the most relevant current approaches to modeling context for ubiquitous computing. Numerous approaches are reviewed, classified relative to their core elements and evaluated with respect to their appropriateness for ubiquitous computing.
This paper discusses the effect of context on mobile usability, proposes an expanded model of mobile application context, and conducts an empirical study to test a number of hypotheses concerning the use of software implementation technology and location context in mobile applications. Four different application types (PC web based, PC device based, mobile web based and mobile device based) were tested using a within-subjects repeated-measures design. The results demonstrate that by utilising client side processing and location context, the mobile device based application is able to achieve objective performance and subjective usability measures comparable to those of the PC based versions, despite the limited input and display capabilities of the mobile device. Conversely, the mobile web based application, which was unable to take advantage of location context or client-side application code, showed the lowest quantitative performance.
Information about the user's environment offers new opportunities and exposes new challenges in terms of time-aware, location-aware, device-aware and personalized applications. Such applications constantly need to monitor the environment - called context - to allow the application to react accordingly to this context. Context-awareness is especially interesting in mobile scenarios where the context of the application is highly dynamic and allows the application to deal with the constraints of mobile devices in terms of presentation and interaction abilities and communication restrictions. Current context-aware applications often realize sensing of context information in an ad hoc manner. The application programmer needs to deal with the supply of the context information including the sensing of the environment, its interpretation and its disposal for further processing in addition to the primary purpose of the application. The close interweavement of device specific context handling with the application obstructs its reuse with other hardware configurations. Recently, architectures providing support for context- aware applications have been developed. Up to now such architectures are not trimmed to the special requirements of mobile devices regarding particularly the limitations of network connections, limited computing power and the characteristics of mobile users. This paper proposes an architecture and a software framework - the Hydrogen Context-Framework - which support context-awareness for considering these constraints. It is extensible to consider all kind of context information and comprises a layered architecture. To prove the feasibility the framework has been implemented to run on mobile devices. A context-aware postbox is realized to demonstrate the capabilities of the framework.
The definition of context experienced an evolution in the research area of context-aware computing, but still suffers from either generality or in-completeness. Furthermore, many definitions are driven by the ease of imple-mentation. This paper introduces two extensions to available context definitions that provide a natural understanding of this concept to users of context-aware applications and facilitates the engineering of this concept for software devel-opers of such applications.
Context-awareness is a key concept in ubiquitous computing. But to avoid developing dedicated context-awareness sub-systems for specific applica- tion areas there is a need for more generic programming frameworks. Such frame- works can help the programmer to develop and deploy context-aware applications faster. This paper describes the Java Context-Awareness Framework- JCAF, which is a Java-based context-awareness infrastructure and programming API for creating context-aware computer applications. The paper presents the design principles behind JCAF, its runtime architecture, and its programming API. The paper presents some applications of using JCAF in three different applications and discusses lessons learned from using JCAF.
Computing is moving toward a pervasive context-aware en- vironment in which agents with limited resources will re- quire external support to help them become context-aware. In this paper, we describe an agent based architecture called Context Broker Architecture (CoBrA) to help these agents to acquire, reason about and share context knowledge. A key component in our architecture is an explicit context on- tology defined using the Web Ontology Language (OWL). This ontology models the basic concepts of people, agents, places, and presentation events. We also describe a use case scenario and prototype design of CoBrA in an intelligent meeting room environment.
Contemporary small screen devices are used as personal companion or communication devices. However, their physical dimensions constrain the processing, communication and user interface capabilities. Thus, rich content presentation and diverse service access via small screen appliances is limited accordingly. This paper introduces the Composite Device Computing Environment (CDCE) that provides a framework for dynamically detecting and utilising surrounding computing resources to overcome the small screen device limitations. CDCE includes the communication infrastructure in addition to supporting alternative models for interactivity between small screen clients and surrounding computing resources.
Context-aware systems offer entirely new,opportunities for application developers and for end users by gathering,context data and adapting systems behaviour accordingly. Especially incombination,with mobile ,devices these mechanisms ,are of high ,value and ,are used to increase usability tremendously. In this paper, we present common architecture principles of context-aware systems and derive a layered conceptual design framework,to explain the different elements common to most context-aware architectures. Based on these design principles, we introduce various existing context-aware systems focusing ,on context-aware middleware ,and frameworks, which ease the development of context-aware applications. We discuss various approaches,and ,analyse important ,aspects in context-aware computing ,on the ,basis of the presented systems. Keywords:context-awarene ss; context framework; context middleware; sensors; context model;
This paper describes systems that examine and react to an individual's changing context. Such systems can promote and mediate people's interactions with devices, computers, and other people, and they can help navigate unfamiliar places. We believe that a limited amount of information covering a person's proximate environment is most important for this form of computing since the interesting part of the world around us is what we can see, hear, and touch. In this paper we define context-aware computing, and describe four catagories of context-aware applications: proximate selection, automatic contextual reconfiguration, contextual information and commands, and contex-triggered actions. Instances of these application types have been prototyped on the PARCTAB, a wireless, palm-sized computer.
The paper discusses the Gaia metaoperating system which extends the reach of traditional operating systems to manage ubiquitous computing habitats and living spaces as integrated programmable environments. Gaia exports services to query, access, and use existing resources and context, and provides a framework to develop user-centric, resource-aware, multidevice, context-sensitive, and mobile applications.
This paper presents ongoing research on context modelling. A review of past research in context awareness shows that researchers have defined and classified context differently. This leads to different views of context amongst different researchers. Moreover, existing context definitions and classifications are ambiguous and therefore it is difficult to carry them forward into design and implementation work. The main aim of this research is to provide a context model that covers key elements of context that researchers should take into account in their designs. Moreover, the relationships between elements are provided by this model. The model provides researchers and practitioners with an integrated point of reference for considering the elements of context and their relationships. This model can then be used as a framework in their implementation of context aware systems.
This paper considers the importance of context in mobile systems. It considers a range of context issues and focus on location as a key issue for mobile systems. A design framework is described consisting of taxonomies of location, mobility, population and device awareness. The design framework informs the construction of a semantic model of space for mobile systems. The semantic model is reflected in a computational model built on a distributed platform that allows contextual information to be shared across a number of mobile devices. The framework supports the design of interactive mobile systems while the platform supports their rapid development. Categories and subject descriptors H.1.2 [Information Systems] User/Machine Systems , C.2.4 [Computer Systems Organization] Distributed Systems - Distributed applications; H.4.3 [Information Systems] Communications Applications , H.5.3 [Information Systems]Group and Organization Interfaces - Synchronous interaction; Theory and Models G...
In this paper the term "implicit human-computer interaction" is defined. It is discussed how the availability of processing power and advanced sensing technology can enable a shift in HCI from explicit interaction, such as direct manipulation GUIs, towards a more implicit interaction based on situational context. In the paper, an algorithm is given based on a number of questions to identify applications that can facilitate implicit interaction. An XML-based language to describe implicit HCI is proposed. The language uses contextual variables that can be grouped using different types of semantics as well as actions that are called by triggers. The term of perception is discussed and four basic approaches are identified that are useful when building context-aware applications. Two examples, a wearable context awareness component and a sensor-board, show how sensor-based perception can be implemented. It is also discussed how situational context can be exploited to improve input and output of mobile devices.
Ubiquitous Computing assumes that users and their computing devices are highly mobile. Because it is unlikely that mobile networks will be equally available in the same quality everywhere, there may be varying levels of connectivity, ranging from full network availability through low-bandwidth connectivity, to no connection at all. As a consequence, software components in the system cannot assume that the connections between them are static and always available. The event-based style is essential for ubiquitous computing, since it offers a good decoupling of the communicating entities in terms of space, time, and program flow. This chapter starts with an introduction to the different interaction models found in distributed systems. Next, a classification of publish/subscribe-systems is presented. We then describe a formal data and filter model that allows us to precisely define the semantics of event filters. Based on this model, we discuss different routing algorithms for the efficient distribution of event notifications in a network. Finally, a number of examples for publish/subscribe systems are presented.
Adaptation is one of the key requirements to handle the increasing complexity in today’s computing environments. This chapter focuses on the aspect of adaptation that puts the user into focus. In this context it introduces the different adaptation types possible for ubiquitous computing services like interaction, content, and presentation. To allow for an automatic adaptation it is important to get some means about the users. Basic requirements to model the users and approaches to personalize applications will be presented.
To support users in performing their tasks, applications need a better understanding of the current situation they are being used in. This chapter gives an overview of how knowledge of the current context, that is, information characterizing the situation, can be represented and how this knowledge can be used for enhancing applications. We discuss what is actually meant by “context” and “context-aware” applications. Further, we describe what has to be considered when building a context-aware application. We thereby focus on the representation of context information and how to deal with its unreliable nature. This chapter should sensitize the reader to the difficulties of using context information and give guidelines on how to build an application that benefits from knowing its current context.
When humans talk with humans, they are able to use implicit situational information, or context, to increase the conversational bandwidth. Unfortunately, this ability to convey ideas does not transfer well to humans interacting with computers. In traditional interactive computing, users have an impoverished mechanism for providing input to computers. By improving the computer’s access to context, we increase the richness of communication in human-computer interaction and make it possible to produce more useful computational services. The use of context is increasingly important in the fields of handheld and ubiquitous computing, where the user?s context is changing rapidly. In this panel, we want to discuss some of the research challenges in understanding context and in developing context-aware applications.
In this paper we present an adapted usability evaluation framework to the context of a mobile computing environment. Using this framework, we conducted a qualitative meta-analytical review of more than 100 empirical mobile usability studies. The results of the qualitative review include (a) the contextual factors studied; (b) the core and peripheral usability dimensions measured; and (c) key findings in the form of a research agenda for future mobile usability research, including open and unstructured tasks are underutilized, interaction effects between interactivity and complexity warrant further investigation, increasing research on accessibility may improve the usability of products and services for often overlooked audiences, studying novel technology and environmental factors will deepen contextual mobile usability knowledge, understanding which hedonic factors impact the aesthetic appeal of a mobile device or service and in turn usability, and a high potential for neuroscience research in mobile usability. Numerous additional findings and takeaways for practitioners are also discussed.
To support users in performing their tasks, applications need a better understanding of the current situation they are being used in. This chapter gives an overview of how knowledge of the current context, that is, information characterizing the situation, can be represented and how this knowledge can be used for enhancing applications. We discuss what is actually meant by "context" and "context-aware" applications. Further, we describe what has to be considered when building a context-aware application. We thereby focus on the representation of context information and how to deal with its unreliable nature. This chapter should sensitize the reader to the difficulties of using context information and give guidelines on how to build an application that benefits from knowing its current context.
Adaptation is one of the key requirements to handle the increasing complexity in today's computing environments. This chapter focuses on the aspect of adaptation that puts the user into focus. In this context it introduces the different adaptation types possible for ubiquitous computing services like interaction, content, and presentation. To allow for an automatic adaptation it is important to get some means about the users. Basic requirements to model the users and approaches to personalize applications will be presented.
Ubiquitous Computing assumes that users and their computing devices are highly mobile. Because it is unlikely that mobile networks will be equally available in the same quality everywhere, there may be varying levels of connectivity, ranging from full network availability through low-bandwidth connectivity, to no connection at all. As a consequence, software components in the system cannot assume that the connections between them are static and always available. The event-based style is essential for ubiquitous computing, since it offers a good decoupling of the communicating entities in terms of space, time, and program flow. This chapter starts with an introduction to the different interaction models found in distributed systems. Next, a classification of publish/subscribe-systems is presented. We then describe a formal data and filter model that allows us to precisely define the semantics of event filters. Based on this model, we discuss different routing algorithms for the efficient distribution of event notifications in a network. Finally, a number of examples for publish/subscribe systems are presented.
To take full advantage of the promise of ubiquitous computing requires the use of location information, yet people should have control over who may know their whereabouts. We present an architecture that achieves these goals for an interesting set of applications. Personal information is managed by User Agents, and a partially decentralized Location Query Service is used to facilitate location-based operations. This architecture gives users primary control over their location information, at the cost of making more expensive certain queries, such as those wherein location and identity closely interact. We also discuss various extensions to our architecture that offer users additional trade-offs between privacy and efficiency. Finally, we report some measurements of the unextended system in operation, focusing on how well the system is actually able to track people. Our system uses two kinds of location information, which turn out to provide partial and complementary coverage.
This paper provides a survey of a chosen set of context-aware middleware systems, and categorises their properties and use according to a taxonomy. An overview of each system is provided, as well as descriptions of the different properties.
A blackboard-based context architecture, being used in the construction of interactive workspaces, was described. The blackboard architecture adopted a data-centric approach in which a process posted messages to a common shared message board, and could subscribe to receive messages matching a specified pattern that were posted. In the architecture, all communications went through a centralized server and routing to different components was effectively accomplished by the matching of message content to a subscriber's pattern.
There is growing interest in the use of context-awareness as a technique for developing pervasive computing applications that are flexible, adaptable, and capable of acting autonomously on behalf of users. However, context-awareness introduces a variety of software engineering challenges. In this paper, we address these challenges by proposing a set of conceptual models designed to support the software engineering process, including context modelling techniques, a preference model for representing context-dependent requirements, and two programming models. We also present a software infrastructure and software engineering process that can be used in conjunction with our models. Finally, we discuss a case study that demonstrates the strengths of our models and software engineering approach with respect to a set of software quality metrics.
This paper describes work carried out as part of the GUIDE project at Lancaster University. The overall aim of the project is to develop a context-sensitive tourist guide for visitors to the city of Lancaster. Visitors are equipped with portable GUIDE units which in turn provide interactive services and dynamically tailored web-based information reflecting the visitor's preferences and environmental context. In contrast to existing tourist systems all information in GUIDE is obtained dynamically using a city-wide wireless network infrastructure. The paper presents an overview of the GUIDE system, with particular focus on our design of an appropriate object model, capable of handling the high degree of flexibility required by GUIDE. In addition, the paper includes the results of our requirements analysis, the web-based application that has been developed to meet these requirements and our approach towards communicating information to portable GUIDE units in a timely and scaleable manner.
Acontextuality of the mobile phone often leads to a caller's uncertainty over a callee's current state, which in turn often hampers mobile collaboration. We are interested in re-designing a Smartphone's contact book to provide cues of the current situations of others. ContextContacts presents several meaningful, automatically communicated situation cues of trusted others. Its interaction design follows social psychological findings on how people make social attributions based on impoverished cues, on how self-disclosure of cues is progressively and interactionally managed, and on how mobility affects interaction through cues. We argue how our design choices support mobile communication decisions and group coordinations by promoting awareness. As a result, the design is very minimal and integrated, in an "unremarkable" manner, to previously learned usage patterns with the phone. First laboratory and field evaluations indicate important boundary conditions for and promising avenues toward more useful and enjoyable mobile awareness applications.
The turn of this century marked an increased focus on mobile usability studies for research in the field of Human Computer Interaction. Such studies offer practitioners the needed insight to deliver usable mobile products and services adopted by consumers at increasing rates contributing to a $20 billion industry. Scholars also benefit by identifying new questions that need to be addressed, thereby enriching our understanding of this dynamic domain within HCI. A challenge for both of these groups exists in that many scholars define and operationalize usability differently. This paper presents a roadmap for future usability research that consists of two parts. First, a framework is adapted for the taxonomy of empirical mobile usability studies. Second, results of the qualitative review of 45 empirical mobile usability studies include: i) the contextual factors studied; ii) the core and peripheral usability dimensions measured; and iii) key findings. Expected contributions of the completed research are also outlined.
Usability is defined in ISO 9241 (1998) as the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction. Usability in relation to mobile services i.e. services that run on Mobile Phones and PDAs must look at the mobile user and surmise what interfaces for mobile services are appreciated and anticipated by the user. This paper will cover the area of usability issues when developing Mobile services. It will look at the mobile users and will propose a system that will store and utilise users' context information to help a user carry out a task. It will formulate a structure that allows applications to learn the significance and interrelations of people, places, objects and documents. By knowing the significance and relationships between objects and data, applications can always provide the user with the most relevant data and build up a context for user interaction.
Context-aware systems represent extremely complex and het- erogeneous distributed systems, composed of sensors, actuators, applica- tion components, and a variety of context processing components that manage the flow of context information between the sensors/actuators and applications. The need for middleware to seamlessly bind these com- ponents together is well recognised. Numerous attempts to build middle- ware or infrastructure for context-aware systems have been made, but these have provided only partial solutions; for instance, most have not adequately addressed issues such as mobility, fault tolerance or privacy. One of the goals of this paper is to provide an analysis of the require- ments of a middleware for context-aware systems, drawing from both traditional distributed system goals and our experiences with developing context-aware applications. The paper also provides a critical review of several middleware solutions, followed by a comprehensive discussion of our own PACE middleware. Finally, it provides a comparison of our so- lution with the previous work, highlighting both the advantages of our middleware and important topics for future research.
Intended for designers and researchers, Context and Consciousness brings together 13 contributions that apply activity theory to problems of human-computer interaction. Understanding how people actually use computers in their everyday lives is essential to good design and evaluation. This insight necessitates a move out of the laboratory and into the field. The research described in Context and Consciousness presents activity theory as a means of structuring and guiding field studies of human-computer interaction, from practical design to theoretical development. Activity theory is a psychological theory with a naturalistic emphasis, with roots going back to the 1920s in the Soviet Union. It provides a hierarchical framework for describing activity and a set of perspectives on practice. Activity theory has been fruitfully applied in many areas of human need, including problems of mentally and physically handicapped children, educational testing, curriculum design, and ergonomics. There is growing interest in applying activity theory to problems of human- computer interaction, and an international community of researchers is contributing to the effort.
Contributors Rachel Bellamy, Susanne Bødker, Ellen Christiansen, Yrjo Engeström, Virginia Escalante, Dorothy Holland, Victor Kaptelinin, Kari Kuutti, Bonnie A. Nardi, Arne Raeithel, James Reeves, Boris Velichkovksy, Vladimir P. Zinchenko
Thesis (Ph. D.)--Columbia University, 1995. Includes bibliographical references (leaves 141-144). Department: Computer Science.
There is growing interest in the use of context-awareness as a technique for developing pervasive computing applications that are flexible, adaptable, and capable of acting autonomously on behalf of users. However, context-awareness introduces various software engineering challenges, as well as privacy and usability concerns. In this paper, we present a conceptual framework and software infrastructure that together address known software engineering challenges, and enable further practical exploration of social and usability issues by facilitating the prototyping and fine-tuning of context-aware applications.
Smart phones are a particularly tempting platform for building context-aware applications because they're programmable and often use well-known operating systems. There's a gap, however, between the operating systems' functionality and the features that application developers need. To fill this gap, we've designed and developed ContextPhone, a software platform consisting of four interconnected modules provided as a set of open source C++ libraries and source code components. ContextPhone runs on off-the-shelf mobile phones using Symbian OS and the Nokia Series 60 Smartphone platform. ContextPhone was developed using an iterative, human-centered design strategy. It thus helps developers more easily create applications that integrate into both existing technologies and users' everyday lives.
A System Architecture for Context-Aware Mobile Computing William Noah Schilit Computer applications traditionally expect a static execution environment. However, this precondition is generally not possible for mobile systems, where the world around an application is constantly changing. This thesis explores how to support and also exploit the dynamic configurations and social settings characteristic of mobile systems. More specifically, it advances the following goals: (1) enabling seamless interaction across devices; (2) creating physical spaces that are responsive to users; and (3) and building applications that are aware of the context of their use. Examples of these goals are: continuing in your office a program started at home; using a PDA to control someone else's windowing UI; automatically canceling phone forwarding upon return to your office; having an airport overheaddisplay highlight the flight information viewers are likely to be interested in; easily locating and using th...
Context-aware computing is an emerging paradigm to free everyday users from manually configuring and instructing computer systems. As the general trend of computing is progressing towards an open and dynamic infrastructure, building context-aware systems can be difficult and costly. In order to build successful context-aware systems, we must develop an architecture to reduce the difficulty and cost of building these systems. This PhD. dissertation proposal describes a research plan to develop a broker-centric agent architecture that is aimed to relieve the burden of capability-limited agents of acquiring and reasoning about contexts, and to protect the privacy of users in a context-aware environment. The implementation of the Context Broker Archiecture will explore Web Ontology Language for modeling contexts and privacy policies, Jess for building a hybrid reasoning mechanism and JADE/FIPA for realizing broker behaviors and agent communications.
The emergence of ubiquitous computing as a new design paradigm poses significant challenges for HCI and interaction design. Traditionally, human-computer interaction has taken place within a constrained and well-understood domain of experience single users sitting at desks and interacting with conventionally-designed computers employing screens, keyboards and mice for interaction. New opportunities have engendered considerable interest in context-aware computing computational systems that can sense and respond to aspects of the settings in which they are used. However, considerable confusion surrounds the notion of context what it means, what it includes, and what role it plays in interactive systems. This paper suggests that the representational stance implied by conventional interpretations of context misinterprets the role of context in everyday human activity, and proposes an alternative model that suggests different directions for design.
Context-aware computing is a mobile computing paradigm in which applications can discover and take advantage of contextual information (such as user location, time of day, nearby people and devices, and user activity). Since it was proposed about a decade ago, many researchers have studied this topic and built several context-aware applications to demonstrate the usefulness of this new technology. Context-aware applications (or the system infrastructure to support them), however, have never been widely available to everyday users. In this survey of research on context-aware systems and applications, we looked in depth at the types of context used and models of context information, at systems that support collecting and disseminating context, and at applications that adapt to the changing context. Through this survey, it is clear that context-aware research is an old but rich area for research. The difficulties and possible solutions we outline serve as guidance for re...
Context-enabled applications are just emerging and promise richer interaction by taking environmental context into account. However, they are difficult to build due to their distributed nature and the use of unconventional sensors. The concepts of toolkits and widget libraries in graphical user interfaces has been tremendously successful, allowing programmers to leverage off existing building blocks to build interactive systems more easily. We introduce the concept of context widgets that mediate between the environment and the application in the same way graphical widgets mediate between the user and the application. We illustrate the concept of context widgets with the beginnings of a widget library we have developed for sensing presence, identity and activity of people and things. We assess the success of our approach with two example context-enabled applications we have built and an existing application to which we have added contextsensing capabilities. Keywords Context-enabled ...
Using activity theory to model context awareness. Modeling and Retrieval of Context: Second International Workshop, MRC 2005, Revised Selected Papers
- Anders Kofod-Petersen
- Jörg Cassens
Anders Kofod-Petersen and Jörg Cassens. Using activity theory to model context awareness. Modeling and
Retrieval of Context: Second International Workshop, MRC 2005, Revised Selected Papers. Volume 3946 of
LNCS (LNAI), pages 1-17, 2006.