Understanding and Using Context (2001)

by A K Dey
Venue:Personal and Ubiquitous Computing Journal
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Results 1 - 10 of 865

A Context Modeling Survey

by Thomas Strang, Claudia Linnhoff-Popien - In: Workshop on Advanced Context Modelling, Reasoning and Management, UbiComp 2004 - The Sixth International Conference on Ubiquitous Computing, Nottingham/England , 2004
"... 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 ap ..."
Abstract - Cited by 292 (2 self) - Add to MetaCart
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. 1.
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Context-Oriented Programming

by Robert Hirschfeld, Pascal Costanza, Oscar Nierstrasz - Journal of Object Technology, March-April 2008, ETH Zurich , 2008
"... Context-dependent behavior is becoming increasingly important for a wide range of application domains, from pervasive computing to common business applications. Unfortunately, mainstream programming languages do not provide mechanisms that enable software entities to adapt their behavior dynamically ..."
Abstract - Cited by 116 (27 self) - Add to MetaCart
Context-dependent behavior is becoming increasingly important for a wide range of application domains, from pervasive computing to common business applications. Unfortunately, mainstream programming languages do not provide mechanisms that enable software entities to adapt their behavior dynamically to the current execution context. This leads developers to adopt convoluted designs to achieve the necessary runtime flexibility. We propose a new programming technique called Context-oriented Programming (COP) which addresses this problem. COP treats context explicitly, and provides mechanisms to dynamically adapt behavior in reaction to changes in context, even after system deployment at runtime. In this paper, we lay the foundations of COP, show how dynamic layer activation enables multi-dimensional dispatch, illustrate the application of COP by examples in several language extensions, and demonstrate that COP is largely independent of other commitments to programming style. 1
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CoOL: A Context Ontology Language to enable Contextual Interoperability

by Thomas Strang, Claudia Linnhoff-Popien, Korbinian Frank - LNCS 2893: Proceedings of 4th IFIP WG 6.1 International Conference on Distributed Applications and Interoperable Systems (DAIS2003). Volume 2893 of Lecture Notes in Computer Science (LNCS)., Paris/France , 2003
"... This paper describes a context modelling approach using ontologies as a formal fundament. We introduce our Aspect-Scale-Context (ASC) model and show how it is related to some other models. A Context Ontology Language (CoOL) is derived from the model, which may be used to enable context-awareness and ..."
Abstract - Cited by 106 (5 self) - Add to MetaCart
This paper describes a context modelling approach using ontologies as a formal fundament. We introduce our Aspect-Scale-Context (ASC) model and show how it is related to some other models. A Context Ontology Language (CoOL) is derived from the model, which may be used to enable context-awareness and contextual interoperability during service discovery and execution in a proposed distributed system architecture. A core component of this architecture is a reasoner which infers conclusions about the context based on an ontology built with CoOL.
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ConnecTables: Dynamic Coupling of Displays for the Flexible Creation of Shared Workspaces

by Peter Tandler, Thorsten Prante, Christian Müller-Tomfelde, Norbert Streitz, Ralf Steinmetz , 2001
"... We present the ConnecTable, a new mobile, networked and context-aware information appliance that provides affordances for pen-based individual and cooperative work as well as for the seamless transition between the two. In order to dynamically enlarge an interaction area for the purpose of shared us ..."
Abstract - Cited by 93 (4 self) - Add to MetaCart
We present the ConnecTable, a new mobile, networked and context-aware information appliance that provides affordances for pen-based individual and cooperative work as well as for the seamless transition between the two. In order to dynamically enlarge an interaction area for the purpose of shared use, a flexible coupling of displays has been realized that overcomes the restrictions of display sizes and borders. Two ConnecTable displays dynamically form a homogeneous display area when moved close to each other. The appropriate triggering signal comes from built-in sensors allowing users to temporally combine their individual displays to a larger shared one by a simple physical movement in space. Connected ConnecTables allow their users to work in parallel on an ad-hoc created shared workspace as well as exchanging information by simply shuffling objects from one display to the other. We discuss the user interface and related issues as well as the software architecture. We also present the physical realization of the ConnecTables.

From Context to Content: Leveraging Context to Infer Media Metadata

by Marc Davis , Marc Davis , Simon King , Nathan Good , Risto Sarvas - In: Proc. of ACM MM 2004 in , 2004
"... ABSTRACT The recent popularity of mobile camera phones allows for new opportunities to gather important metadata at the point of capture. This paper describes a method for generating metadata for photos using spatial, temporal, and social context. We describe a system we implemented for inferring l ..."
Abstract - Cited by 84 (7 self) - Add to MetaCart
ABSTRACT The recent popularity of mobile camera phones allows for new opportunities to gather important metadata at the point of capture. This paper describes a method for generating metadata for photos using spatial, temporal, and social context. We describe a system we implemented for inferring location information for pictures taken with camera phones and its performance evaluation. We propose that leveraging contextual metadata at the point of capture can address the problems of the semantic and sensory gaps. In particular, combining and sharing spatial, temporal, and social contextual metadata from a given user and across users allows us to make inferences about media content.
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Travel recommender systems

by Francesco Ricci - IEEE Intelligent Systems
"... Mobile phones are becoming a primary platform for information access and when coupled with recommender systems technologies they can become key tools for mobile users both for leisure and business applications. Recommendation techniques can increase the usability of mobile systems providing personal ..."
Abstract - Cited by 68 (15 self) - Add to MetaCart
Mobile phones are becoming a primary platform for information access and when coupled with recommender systems technologies they can become key tools for mobile users both for leisure and business applications. Recommendation techniques can increase the usability of mobile systems providing personalized and more focussed content, hence limiting the negative effects of information overload. In this paper we review the major issues and opportunities that the mobile scenario opens to the application of recommender systems especially in the area of travel and tourism. We overview major techniques that have been proposed in the last years and we illustrate the supported functions. We also illustrate specific computational models that have been proposed for mobile recommender systems and we close the paper by presenting some possible future developments and extension in this area. 1

Context-awareness on mobile devices – the hydrogen approach

by Thomas Hofer, Mario Pichler, Gerhard Leonhartsberger, Josef Altmann, Werner Retschitzegger - Proceedings of the 36th Annual Hawaii International Conference on System Sciences , 2002
"... 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 accor ..."
Abstract - Cited by 61 (1 self) - Add to MetaCart
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 contextaware 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.
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The Design and Applications of a Context Service

by Hui Lei , Daby M. Sow , John S. Davis II, Guruduth Banavar, Maria R. Ebling
"... 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 examp ..."
Abstract - Cited by 59 (6 self) - Add to MetaCart
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.

Video Search Reranking through Random Walk over Document-Level Context Graph

by Winston H. Hsu, et al. , 2007
"... Multimedia search over distributed sources often result in recurrent images or videos which are manifested beyond the textual modality. To exploit such contextual patterns and keep the simplicity of the keyword-based search, we propose novel reranking methods to leverage the recurrent patterns to im ..."
Abstract - Cited by 57 (8 self) - Add to MetaCart
Multimedia search over distributed sources often result in recurrent images or videos which are manifested beyond the textual modality. To exploit such contextual patterns and keep the simplicity of the keyword-based search, we propose novel reranking methods to leverage the recurrent patterns to improve the initial text search results. The approach, context reranking, is formulated as a random walk problem along the context graph, where video stories are nodes and the edges between them are weighted by multimodal contextual similarities. The random walk is biased with the preference towards stories with higher initial text search scores – a principled way to consider both initial text search results and their implicit contextual relationships. When evaluated on TRECVID 2005 video benchmark, the proposed approach can improve retrieval on the average up to 32 % relative to the baseline text search method in terms of story-level Mean Average Precision. In the people-related queries, which usually have recurrent coverage across news sources, we can have up to 40 % relative improvement. Most of all, the proposed method does not require any additional input from users (e.g., example images), or complex search models for special queries (e.g., named person search).
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An Integrated Approach to Engineer and Enforce Context Constraints in RBAC Environments

by Mark Strembeck, Gustaf Neumann - ACM Transactions on Information and System Security (TISSEC , 2004
"... this paper appeared in the Proceedings of the 8th ACM Symposium on Access Control Models and Technologies (SACMAT 2003) ..."
Abstract - Cited by 55 (18 self) - Add to MetaCart
this paper appeared in the Proceedings of the 8th ACM Symposium on Access Control Models and Technologies (SACMAT 2003)