• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.165-174
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• 2006

As context aware service supports a process of context acquisition and reasoning, there are many studies to facilitate the implementation of context aware service. However, these studies have not supported efficiently a user or service mobility that should be supported necessarily in ubiquitous computing environment. Therefore, this study proposes a dynamic context aware service model which supports a dynamic management of context information, service retrieval and composition for interactions between services, and service mobility. Then we design a middleware based on this model and implement the middleware. As the middleware is implemented on the OSGi framework. it can have an interoperability between the devices such as computers, PDA, home appliances, and sensors, because of using the standard interface technologies like UPnP. Jini and so on.

• Journal of Information Technology Applications and Management
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• v.14 no.2
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• pp.11-26
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• 2007

In this paper we suggest a context-driven configuration model of virtual businesses to form a business network model consisting of role-based, interaction-centered business partners. The model makes use of the subcontext concept which explicitly represents actors and interactions in virtual business (VB) context. We separate actors who have capacities on tasks in a specific kind of role and actor subcontext which models requirements in specific interaction subcontext. Three kinds of actors are defined in virtual service chains, service user, service provider, and external service supporter. Interaction subcontext models a service exchange process between two actor subcontexts with consideration of context dependencies like task and quality dependencies. Each subcontext may be modeled in the form of a situation network which consists of a finite set of situation nodes and transitions. A specific situation is given in a corresponding context network of actors and interactions. It is illustrated with a simple example.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.2
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• pp.95-100
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• 2007

Recently ubiquitous application services are developed plentifully using RFID techniques in the field of distribution and security industries. However, except these field the applications using RFID are not mature yet. In this study, we proposed a real-time context service model of the u-conference based on the real-time contextual information acquired from conference and exposition. With collection of real-time contextual information for u-conference, the model can provide a lot of information services on the state of session attendee, doorway control, affairs, user certification, presentation progress etc. For the verification of proposed real-time context service model of u-conference, we design and implement the conference progress state service included the state of session attendee, user certification and presentation progress etc. This service provides the presentation state information included the current presenter, the paper list, the number of session attendee, the schedule and place of each session using the collecting RFID tag and the related information.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.845-848
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• 2004

Ubiquitous Computing 환경은 컴퓨터 중심의 환경이 아닌 사용자가 편리성과 효율성이 극대화된 서비스들을 제공 받을 수 있는 사용자 중심의 환경이다. 이러한 환경에서 사용자들은 자신의 정보가 언제 어디서 사용되고 있고 어떠한 목적으로 유출되고 있는지 알기 어렵다. 따라서 사용자를 식별하고 개인의 특성에 따라 관련된 서비스를 제공하는데 있어 사용자의 필요정보를 적절하게 보호할 수 있는 메커니즘이 필요하다. 본 논문에서는 Ubiquitous환경에서 특정목적에 국한된 서비스 제공이 아닌 다양한 목적에 따라 서비스가 제공될 수 있도록 사용자의 목적과 상황에 맞는 User Model을 제안하고자 한다. 또한 사용자의 상황에 맞는 Context Content를 구별하여 Privacy등급을 결정하고 사용자마다 독립적이고 안전한 Context-Aware Service를 제공하는 User Model은 사용자마다 정해진 정적 Context와 상황에 따라 변화하는 동적 Context를 모두 고려하여 높은 신뢰성과 안전성을 지닌 방법을 제공한다. 그리고 제안된 User Model의 정의와 시나리오를 설명한다.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.429-436
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• 2013

Context aware environment u-health service is to provide health service with recognition of a computer. The computer recognizes that a patient can contact real life in many context. Context aware environment service for recommend have to definition of context data and service recommendations related to factors shall be identified. In this paper, Context aware environment of u-health service will be provide context data related to identifies recommendations factors using multivariate analysis method and recommendations factors creation to decision tree, association rule based decision model. health service recommend for significantly context data can be distinguish through recommendation factors of identify. Also, context data of patient can know preference factors through preference decision model.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.6
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• pp.121-130
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• 2020

In order to provide customized services according to a specific user or environment, various service scenarios should be developed based on context-aware workflow model. As the context-aware workflow model is constructed using limited context information and service information in the service domain, overlapping elements can occur in many service scenarios. The repetitive work process that results from these overlapping elements delays the development process of the service scenario. Therefore, the elements of the context-aware workflow model must be reused to solve the unnecessary work processes of service scenario development. In this paper, we propose a reuse method XML Object in context-aware workflow model to improve the process of service scenario development. The proposed method documents and manages the independent XML Object of the context-aware workflow model and reuses it by invoking the unit document in the service scenario development process. It can also be applied to new service scenarios by changing the attribute values of reusable elements. Experiments show example that the development process of the service scenario is simplified by reusing the elements of the context-aware workflow model.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.51-57
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• 2009

There are a variety of users and devices in a context-aware computing environment. In this environment, the service provided to a user may be the composition of diverse services rather than one independent service. Before user's devices provide the composite service to the user, they should perceive user's needs by gathering related information segments from other surrounding devices and/or sensors. We consider a context-aware computing environment providing composite and adapted service to users and propose an information processing model that characterizes the device where the collected data should be processed through services and/or applications. Based on this model, we provide an analytical tool to obtain some performance measures of the context-aware computing environment.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.457-464
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• 2005

This paper describes an Adaptive Context-aware Service (ACS) using Model Driven Architecture (MDA)-based Service Creation Environment (SCE) on PARLAY X based service delivery platform in ubiquitous computing environments. It can be expected that both the context-awareness and adaptation in ubiquitous computing environments will be deployed. But the existing context-aware middleware lacks in considering adaptation. Therefore, the object of this paper is to support the architecture and the Application Programming Interface (API) of the network service for both the context-awareness and adaptation in ubiquitous computing environment. ACS is to provide users with the adaptive network service to the changing context constraints as well as detecting the changing context. For instance, ACS can provide users with QoS in network according to the detected context, after detecting the context such as location and speed. The architecture of ACS is comprised of a Service Creation Environment (SCE), Adaptive Context Broker and PARLAY gateway. SCE is to use Context-based Constraint Language (CCL) for an expression of context-awareness and adaptation. Adaptive Context Broker is to make a role of the broker between SCE and PARLAY G/W. PARLAY G/W is to support API for PARLAY X-based service delivery platform.

• 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.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.22-30
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• 2011

In the IT convergence environment changed with not only the quality but also the material abundance, it is the most crucial factor for the strategy of personalized recommendation services to investigate the context information. In this paper, we proposed the recommendation using the service ontology based context awareness modeling. The proposed method establishes a data acquisition model based on the OSGi framework and develops a context information model based on ontology in order to perform the device environment between different kinds of systems. In addition, the context information will be extracted and classified for implementing the recommendation system used for the context information model. This study develops the ontology based context awareness model using the context information and applies it to the recommendation of the collaborative filtering. The context awareness model reflects the information that selects services according to the context using the Naive Bayes classifier and provides it to users. To evaluate the performance of the proposed method, we conducted sample T-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.