• The KIPS Transactions:PartD
• /
• v.13D no.6 s.109
• /
• pp.789-796
• /
• 2006

Context-aware is the core in ubiquitous environment of sensor network to support intelligent and contextual adaptation service. The new context information model is demanded to support context-aware applications. The model should not depend on a specified application and be shareable between applications in the same environment. Also, it should support various context representation and complex context-aware. In this paper, we define the context information according to context-aware process. Also we design the knowledge of domain as well as applications using ontologies and rules. The domain spatial ontology and application knowledge are represented using the spatial object model and the rules of expanded ontologies, respectively. The expression of abundant spatial ontology represents the context information about distance between objects and adjacent object as well as the location of the object. The proposed context information model which is able to exhibit various spatial context and recognizes complex spatial context through the existing GIS. This model shows that it can adapt to a large scale outdoor context-aware applications such as air pollution and prevention of disasters as well as various context-aware applications.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.16 no.6
• /
• pp.659-664
• /
• 2006

The Context-Aware system is the core technology in the Ubiquitous Computing Environment. Recently, the practical use of a sensor is magnified and the application fields of it are gradually extended in order to collect necessary context information. Context-Aware service integrates the context information which is collected by sensors, and then provides, a suitable service to a user through the process of analysis and reasoning. This service is studied in a variety of fields such as marketing, medical treatment, education and so on. In this paper, we analyze the method of recognizing surrounding context and the result of the awareness by using differential and structural property of multiple valued logic function; propose the model that provides appropriate service depending on the change of surrounding contort; confirm the applicability of the Context-aware system by showing the example of application.

• KSCI Review
• /
• v.14 no.1
• /
• pp.165-173
• /
• 2006

To support service based on context-aware in ubiquitous computing environment, there are required context managing, context reasoning and context modeling technologies. In this paper, we propose a hierarchical ontology-based context management model and design a context-aware middleware based on this model for supporting active application adaptability and reflecting users' requirements dynamically in contextual changes. It also provides efficient support for inferencing, interpreting, acquiring and discovering various contexts to build context-aware services and presents a resolution method for context conflict which is occurred in execution of service. The proposed middleware can support the development and operation of various context-aware services, which are required in the ubiquitous computing environment.

• Journal of KIISE:Software and Applications
• /
• v.30 no.5_6
• /
• pp.550-558
• /
• 2003

Context-aware application plays an important role in ubiquitous computing (ubiComp) environment by providing user with anytime, anywhere services even without any explicitly triggered command. In this paper we propose a unified context-aware application model which is an essential part to develop various applications in ubiquitous computing environment. The proposed model affirms the independence between sensor and application by using unified context in the form of 5W1H. It also ensures that application exploits relatively accurate context to trigger personalized services. To show usefulness of the proposed model, we apply it to the sensors and applications in the ubiHome, a test bed for ubiComp-enabled home applications. According to the experimental results, without loss of generality, we believe it can be extended to various context-aware applications in daily life.

• The Journal of Korea Robotics Society
• /
• v.2 no.1
• /
• pp.80-92
• /
• 2007

For the pervasive computing in ubiquitous environment, it is very important to manage the context model to provide pertinent context knowledge to context-aware applications. The context model should be able to support efficiently the context knowledge reusing and sharing as well as reasoning. Previous works focus mainly on the context knowledge representation scheme for reasoning. This paper proposes a context knowledge modeling scheme especially for reusing and sharing. This scheme provides well-established principles and guides for 1) context knowledge modularization and hierarchization, and for 2) context knowledge identification and organization. Once the context models are built according to the scheme, the structure of the context model and the meanings of the context knowledge elements become clear and consistent, so that context-aware applications can share and reuse the context knowledge in easy and error-reduced manner. This paper also discusses the implementation of a context model and an application for Presentation Helper scenario running on a software middleware system (CAMUS) for ubiquitous service robots which is being developed by ETRI Korea.

• Journal of KIISE:Software and Applications
• /
• v.33 no.1
• /
• pp.105-113
• /
• 2006

In this paper we propose wear-UCAM, which is a toolkit for context-aware application model in wearable computing. As the rapid developments of mobile technologies and relevant technologies, the interests in wearable computer also become indispensible in both academic and industrial fields. However, there are few research activities on the application framework or toolkit for wearable computing. Hence, we suggest wear-UCAM as the development toolkit for wearable computing applications, where we focus on how to collect relevant user context, manage it, and provide services based on the recognized context. The proposed wear-UCAM includes the abstraction of context processing as well as independence among sensors and services with other components. For the sake of rapid prototyping of the proposed toolkit, we utilize PDA with wireless LAN as a wearable computer. The detail explanation of the implementation and its discussion are presented in this paper.

• The KIPS Transactions:PartC
• /
• v.13C no.6 s.109
• /
• pp.691-700
• /
• 2006

To support context-aware services in ubiquitous computing environments, there are required dynamic context managing, context reasoning and context modeling technologies. In previous researches, context services are designed using context ontology used in context aware middleware. So, context service cannot change the context ontology in execution time. In this paper, we propose a hierarchical ontology-based context management model and design a context-aware middleware based on this model for supporting active application adaptability and reflecting users' requirements dynamically in contextual changes. It also provides efficient support for inferencing, interpreting, acquiring and discovering various contexts to build context-aware services and presents a resolution method for context conflict which is occurred in execution of service. As the middleware is implemented on the OSGi framework, it can cause interoperability among devices such as computers, PDAs, home appliances and sensors. It can also support the development and operation of context aware services, which are required in the ubiquitous computing environment.

• KIPS Transactions on Computer and Communication Systems
• /
• v.5 no.11
• /
• pp.411-418
• /
• 2016

Context-aware application has a lot of power consumption because it creates context by using a number of smartphone's sensors. Furthermore, only few kinds of researches have been conducted that provide information for the evaluation result of power consumption in the aspect of applications. In addition, evaluation of power consumption do not consider user's usage pattern or provide only total amount of power consumption, and inform developers power consumption of sensors undistinguishable. It makes developers hard to develop a power consumption-considered application. If developers could get information for power consumption of context-aware application in detail, a development of power-considered context-aware applications would be possible. Consequently, this paper proposes a BMT(Bench Mark Test) model which is able to inform developers useful evaluation criteria and result about power consumption of smartphone's components and sensors with usage pattern considered.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.6
• /
• pp.99-109
• /
• 2011

Ubiquitous computing technology makes an impact on the appearance of u-learning and presents an advanced direction of futuristic school education. In ubiquitous learning environments, various embedded computational devices will be pervasive and interoperable across the network for supporting the learning, so users may utilize these devices anytime anywhere. An important next step for ubiquitous learning is the introduction of context-aware learning service that employing knowledge and reasoning to understand the local context and share this information in support of intelligent learning services. However, the existing studies on design and application of ontology context model to support context-aware service in actual school environments are incomplete state. This paper, therefore, suggests a scheme of constructing ubiquitous learning space for existing school network by introducing USN to support context-aware ubiquitous learning services. This paper, also, designs an ontology based context model for ubiquitous school environments which describes context information through OWL. To determine the suitability of proposed ubiquitous learning space and ontology context model, we implement some of context-aware learning services in the ubiquitous learning environments.

• Journal of the Institute of Convergence Signal Processing
• /
• v.10 no.4
• /
• pp.225-232
• /
• 2009

Context-aware technologies for ubiquitous computing are necessary to study the representation of gathered context-information appropriately, the understanding of user's intention using context-information, and the offer of pertinent services for users. In this paper, we propose the WS-CAM(Web Services based Context-Aware Middleware) framework for context-aware computing. WS-CAM provides ample power of expression and inference mechanisms to various context-information using an ontology-based context model. We also consider that WS-CAM is the middleware-independent structure to adopt web services with characteristic of loosely coupling as a matter of communication of context-information. In this paper, we describe a scenario for lecture services based on the ubiquitous computing e e e e e e to verify the utilization of WS-CAM We also show an example of middleware-independent system expansion to display the merits of web-based services. WS-CAM for lecture services represented context-information itodomaits as OWL-based ontology model effectively, and we confirmed the information is inferred to high level context-information by user-defined rules. We also confirmed the context-information is transferred to application services middleware-independently using various web methods provided by web services.