• Journal of Information Processing Systems
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• v.10 no.4
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• pp.581-588
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• 2014

To facilitate the implementation of a wide variety of context-aware applications based on mobile devices, general-purpose context-aware framework that applications can use by calling is needed. The context-aware framework is a middleware that performs the sensing, reasoning, and retrieving based on the knowledge base. The knowledge base must systematically represent the information required on the behavior of the context-aware framework, such as context information and reasoning information. It must also provide functions for storage and retrieval. To date, previous research on the representation of the context information have been carried out, but studies on the unified representation of the knowledge base has seen little progress. This study defines the knowledge base as the unified context information, and proposes the UniOWL, which can do a good job of representing it. UniOWL is based on OWL and represents the information that is necessary for the operation of the context-aware framework. Therefore, UniOWL greatly facilitates the implementation of the knowledge base on a context-aware framework.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.225-228
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• 2005

A context-aware services platform supporting mobile agents consists of sensor nodes and a sensor coordinator. Sensor nodes collect environmental information and transmit the collected information to the sensor coordinator through wireless sensor networks. The sensor coordinator passes the information to the context-aware service module, and the mobile agent. The context-aware service module or the mobile agent performs services suitable for a user's situation based on the environmental information and a service actuation message is delivered to an actuation node through the sensor coordinator. In this paper, we present a context-aware services platform structure employed in our project, and describe context-aware services platform interfaces with a context-aware service module and mobile agents.

• Journal of the HCI Society of Korea
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• v.8 no.1
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• pp.11-17
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• 2013

Context aware systems are those systems that are aware about the environment and perform productive functions automatically by reducing human computer interactions(HCI). In this paper, we present common architecture principles of context-aware systems to explain the important aspects of context aware systems. Our study focuses on identifying common concepts in pervasive computing approaches, which allows us to devise common architecture principles that may be shared by many systems. The principles consists of context sensing, context modeling, context reasoning, context processing, communication modelling and resource discovery. Such an architecture style can support high degree of reusability among systems and allows for design flexibility, extensibility and adaptability among components that are independent of each other. We also propose a new architecture based on broker-centric middleware and using ontology reasoning mechanism together with an effective behavior based context agent that would be suitable for the design of context-aware architectures in future systems. We have evaluated the proposed architecture based on the design principles and have done an analyses on the different elements in context aware computing based on the presented system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.3
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• pp.19-31
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• 2008

Currently, RFID is receiving attention from the industry and the academy because it is considered as an enabling technology for ubiquitous computing, in particular context perception. In this paper, we survey the existing context-aware RFID systems and introduce three main issues in the systems - the context information, the context-aware services, and the context-aware RFID system architectures. We classify context information into six groups, the services into five context-aware service types, and the systems into four architecture styles. This study will help stakeholders such as customers and developers to understand their RFID systems and to develop new services.

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

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.613-615
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• 2004

유비쿼터스 컴퓨팅 환경에서 가장 중요한 이슈중의 하나는 상황인지(Context-Aware)가 가능한 환경을 구축하는 것이다. Context-Aware 환경이 구축되면 주변의 상황을 감지하여 특정 어플리케이션을 실행한다거나, 시스템을 재구성하는 등의 일을 수행할 수 있다. 그동안 이런 상황인지가 가능한 환경을 Context-Aware 미들웨어를 통해 구현하려는 연구가 많이 수행되었다. Context-Aware 미들웨어를 구현하기 위해 무엇보다도 중요한 것은 실제 세계의 다양한 종류의 상황을 컴퓨팅 환경에 적용시키는 것이다. 그러나 현실 세계에서 Context의 종류는 거의 무한하다고 할 수 있다. 기술이 발전하게 되면서 인지 가능한 Context의 종류도 무한정 늘어나게 될 것이다 또한 실제 세계에서의 Context들은 추상적인 경우가 많이 있다. 그러나 Context가 추상적이라 해도 다른 Context 정보를 이용해서 구체화 할 수 있다. 이런 과정을 위해 Conte지들을 계층적으로 관리해야 할 필요가 있다. 본 논문에서는 Context-Aware 미들웨어를 구현할 때 Context들의 이런 여러 가지 특성들을 고려해서 Context Type을 관리랄 수 있는 하나의 객체를 제안하고, 다른 방법들과 비교, 분석해 보았다.

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

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.346-350
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• 2009

According to the development of information technology, there are many services in our life. These services make our life safe and convenient. However, the increment of the services also causes the increment of human concern and effort to control these services. The context-aware service is the service that provided their functionality at the right time and to the right place by analysis user's current situation. The most previous studies about context-aware service regard that context-aware services are defined by the developer who has expertise in information technology. The definition of the context-aware services by the developer makes difficult to reflect user's personal preferences and life pattern to the services. In this paper, we propose an user interface EUCAS(by End-User, Context-Aware Service development) that make the user can define and manage their own context-aware service according to their preferences. We expect EUCAS can be effective user interface technology for providing personalized context-aware service.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.4
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• pp.254-259
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• 2008

Uncertainty of result of context awareness always exists in any context-awareness computing. This falling-off in accuracy of context awareness result is mostly caused by the imperfectness and incompleteness of sensed data, because of this reasons, we must improve the accuracy of context awareness. In this article, we propose a novel approach to model the uncertain context by using ontology and context reasoning method based on Bayesian Network. Our context aware processing is divided into two parts; context modeling and context reasoning. The context modeling is based on ontology for facilitating knowledge reuse and sharing. The ontology facilitates the share and reuse of information over similar domains of not only the logical knowledge but also the uncertain knowledge. Also the ontology can be used to structure learning for Bayesian network. The context reasoning is based on Bayesian Networks for probabilistic inference to solve the uncertain reasoning in context-aware processing problem in a flexible and adaptive situation.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.27-44
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• 2008

Owl-based ontology is useful to realize the context-aware services which are composed of the distributed and self-configuring modules. Many ontology-based inference engines are developed to infer useful information from ontology. Since these engines show the uniqueness in terms of speed and information richness, it's difficult to ensure stable operation in providing dynamic context-aware services, especially when they should deal with the complex and big-size ontology. To provide a best inference service, the purpose of this paper is to propose a novel methodology of context-aware engine selection in a contextually prompt manner Case-based reasoning is applied to identify the causality between context and inference engined to be selected. Finally, a series of experiments is performed with a novel evaluation methodology to what extent the methodology works better than competitive methods on an actual context-aware service.