عنوان مقاله [English]
The ubiquity of mobile devices, such as smart phones and tablets, has contributed to the development of pervasive systems, including navigation and health systems. The main characteristicsof pervasive systems are the necessity of dynamic reconfiguration and proper adaptation to the continuous changes in different contexts. The existence of dynamic capabilities has been considered in the design and implementation of a context aware system, including context acquisition, context understanding and computing, decision making, and context presentation.Context acquisition: This domain of research focuses on using personal sensing devices which measure various parameters by means of portable devices and save them on the external/internal database for further processing. The aim of researches is collecting, sharing, and/or reusing data in other applications or through a web interface.Context understanding and computing: The most works are in the field of context monitoring, data management, understanding or computing. The ability to automate context reasoning about various types of contexts and their properties are considered using various context models and algorithms. Most applications are customized for a specific case such as air pollution, tourist, navigation, and health care. Context presentation: This category of research has commonly focused on context-aware application adaptation. The adaptation happens between the real world, the map and user’s location and orientation. A number of studies have been carried out in the field of tourist guides or navigation adapting the presentation style to the changing requirements of the user.Most studies in ubiquitous health care have only been carried out in a small number of areas and using external portable sensors and developing applications on mobile phones. A major problem with these kinds of applications is collecting and sharing data, monitoring, or reasoning without having an active role in decision making in different environmental conditions. Using external tools such as portable devices is costly and limits using the systems.
This paper has focused on the design and implementation of a context aware ubiquitous system which has been customized for severe environmental conditions (in particular, air pollution). Air pollution is a spatial-temporal phenomenon and it causes changes in health conditions and it increases mortality. Eclipse Kepler software, java, PHP programming language and MySQL and SQLit database and also Google Maps API was used in this research. The proposed system design approach is based on distributed architecture in the portion of data collection and processing. Data collecting is done by means of software and hardware sensors. The context aware system is able to automatically identify the user’s context and represent required data and information after computing and reasoning. Contexts based on their impact on the decision-making process can be divided into two categories: passive and active contents.We used an active context in the research such as time, location, traffic, direction, air pollution. Collecting required data is done automatically with high speed and accuracy, and data plays an active role in decision making. In the system architecture, servers were embedded to enter data automatically and only data relating to health conditions is entered manually. Processing environment was divided into two parts, in case of abounding calculations, processing is transferred to the server so that only light processing is performed on the client. At every stage of the process, the user interface provided outputs in the form of recommendations and notifications. The system represents user-friendly environment. Context information can be posted on the process server and retrieved from the history. The proposed system can become an important tool to enable patients to be aware of air pollution conditions, not only to be applied in managing and monitoring their health information, but also in decision making, finding the best solution in severe environment, sharing data and communicating with family and doctor. The application represents suitable solution for solving the shortest path problem according to spatial-temporal and traffic condition. In fact, the path with the lowest level of air pollution is chosen as the best path.The system indirectly encourages greater use of the ubiquitous health system and motivates patients to acquire an active role in their health management and helps them to improve their health condition. The information collected and posted on the server can be reused in professional station and it presents useful information to health experts. We are broadly concerned about patients’ privacy in the design of the system.