|
Spatial contextual awareness consociates contextual information such as an individual’s or sensor’s location, activity, the time of day, and proximity to other people or objects and devices.〔Chen, Guanling, and David Kotz. 2000. A Survey of Context-Aware Mobile Computing Research. Dartmouth Computer Science Technical Report TR2000-381.〕 It is also defined as the relationship between and synthesis of information garnered from the spatial environment, a cognitive agent, and a cartographic map. The spatial environment is the physical space in which the orientation or wayfinding task is to be conducted; the cognitive agent is the person or entity charged with completing a task; and the map is the representation of the environment which is used as a tool to complete the task.〔Freksa, Christian, Alexander Klippel, and Stephan Winter. 2005. A Cognitive Perspective on Spatial Context. Dagstuhl Seminar Proceedings 05491.〕 An incomplete view of spatial contextual awareness would render it as simply a contributor to or an element of contextual awareness – that which specifies a point location on the earth. This narrow definition omits the individual cognitive and computational functions involved in a complex geographic system. Rather than defining the myriad of potential factors contributing to context, spatial contextual awareness defined in terms of cognitive processes permits a unique, user-centered perspective in which “conceptualizations imbue spatial structures with meaning.”〔 Context awareness, geographic awareness, and ubiquitous cartography or Ubiquitous Geographic Information (UBGI) all contribute to the understanding of spatial contextual awareness. They are also key elements in a map-based, location-based service, or LBS. In cases in which the user interface for the LBS is a map, cartographic design challenges must be addressed in order to effectively communicate the spatial context to the user. Spatial contextual awareness can describe present context – the environment of the user at the present time and location, or that of a future context – where the user wants to go and what may be of interest to them in the approaching spatial environment. Some location-based services are proactive systems which can anticipate future context.〔Mayrhofer, Rene, Harald Radi, and Alois Ferscha. 2003. Recognizing and Predicting Context by Learning from User Behavior. In ''The International Conference On Advances in Mobile Multimedia (MoMM2003)'', ed. W. Schreiner, G. Kotsis, A. Ferscha, and K. Ibrahim, volume 171, pages 25–35. Austrian Computer Society (OCG), September 2003.〕 Augmented reality is an application which guides a user through present and into future context by displaying spatial contextual information in their visual system as they traverse through real space.〔Gartner, Georg. 2007a. Development of Multimedia – Mobile and Ubiquitous. In ''Multimedia Cartography'', ed. William Cartwright, Michael P. Peterson, and Georg Gartner, 51-62. Springer-Verlag Berlin Heidelberg.〕 Numerous examples of LBS applications exist which require the ability to leverage spatial contextual awareness. These applications are in demand by the general public and are examples of how maps are being used by individuals to help better understand the world and make daily decisions.〔Peterson, Michael P. 2007a. Elements of Multimedia Cartography. In ''Multimedia Cartography'', ed. William Cartwright, Michael P. Peterson, and Georg Gartner, 63-73. Springer-Verlag Berlin Heidelberg.〕 ==Context awareness== Context awareness originated as a term from ubiquitous computing or as so-called pervasive computing which sought to deal with linking changes in the environment with computer systems, which are otherwise static.〔Context awareness〕 Context is defined in multiple ways, most often with location as the cornerstone. One source defines it as “location and the identity of nearby people and objects.” Another describes it as “location, identity, environment and time”.〔Jiang, Bin, and Xiaobai Yao. 2007. Location Based Services and GIS in Perspective. In ''Location Based Services and TeleCartography'', ed. Georg Gartner, William Cartwright, and Michael P. Peterson, 27-45. Springer-Verlag Berlin Heidelberg.〕 Yet some definitions recognize context awareness as being more inclusive than location. Dey〔Dey, Anind K. 2001. Understanding and Using Context. ''Personal and Ubiquitous Computing'', Volume 5, 4-7. Springer London.〕 took this broader approach: “context is any information that can be used to characterize the situation of an entity, where entity means a person, place, or object, which is relevant to the interaction between a user and an application, including the user and the applications themselves.” The same author defined a system “to be context-aware if it uses context to provide relevant information and/or services to the user, in which the relevancy depends on the user’s task”.〔 The concept of relevancy is described in the following definition of context awareness: “the set of environmental states and settings that either determines an application’s behavior or in which an application event occurs and is interesting to the user”.〔 Different levels of context, in terms of low and high level have also been outlined. Low-level contexts consist of time, location, network bandwidth and orientation. A high-level context consists of the user’s current activity and social context.〔 A three-level model of context awareness (Figure 1) includes the changeable nature of the environment by differentiating between the contributions of static, dynamic, and internal context:〔Li, Ki-Joune. 2007. Ubiquitous GIS, Part I: Basic Concepts of Ubiquitous GIS, Lecture Slides, Pusan National University.〕 * Static context – stored digital geographic information which could impact the user’s environment * Dynamic context – information on the changeable aspects of the user’s environment obtained by sensors/info services and provided in real time (e.g. weather forecasts, traffic reports) * Internal context – user information, to include personal preferences, location, speed, and orientation Static content is driven by stored information while dynamic content is provided and updated by sensors. Context categories for mobile maps have been identified through pilot user tests. The categories in Table 1 were deemed useful for mobile map services:〔 Table 1:〔 Context Categories 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Spatial contextual awareness」の詳細全文を読む スポンサード リンク
|