• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.2
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• pp.202-207
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• 2007

Ontology has many merits such as high expression power and extensibility etc. and there are some suggestion on development of ubiquitous environment using ontology. For collecting and analysing the context information in ubiquitous environment, we need a context-awareness system. For these reason, some context-awareness systems have been developed using ontology, but they have insufficient representation power of context information and are independent to domain. In this paper, we define the context type to improve the extensibility of context framework, and develop the context ontology adopting the defined contort type to represent or inference various context information. We define the ontology to be easily adopted the and domain. Also, we use SWRL to represent numerical formulas and Horn-Logic expression.

• Korean Journal of Social Welfare
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• v.65 no.4
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• pp.195-220
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• 2013

The purpose of this study is to discover the context and pattern of turnover social workers have experienced. To achieve this purpose, researchers collected data from in-depth interviews with seven social workers who have experiences of turnover and analysed the data using context-pattern analysis method. Research findings are composed of individual context-pattern analysis and integrated context-pattern analysis. In individual context-pattern analysis, researchers mixed time-dimension(before turnover/on the process/after turnover) and level-dimension(experienced phenomenon/meaning of experiences/context connected with phenomenon and meaning) and analysed the context of every stages and serial pattern. Also, we connected with each contexts and patterns and integrated the context-pattern of turnover. Integrated context-pattern structure is divided for four areas; organization before turnover, organization after turnover, social worker as a stakeholder of turnover, and network of social worker. Based on the results of the study, administrative recommendations were suggested in order to manage the turnover of social workers in social work fields.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.537-546
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• 2004

In order to develop an application software for context-awareness techniques, we should program both all decisions on variable con-text-awareness and appropriate process with some program languages. These cause a loss of software production and unlimited repetition of program code. In this paper, we implement a context script language and language processor which can simplify a series of involved process acquired for context-awareness and describe them clearly. In addition, it can represent a definitions of context as standard syntax as well as accomplish them automatically. The proposed context script language provides functionality which can not only define efficiently a given context but also describe a variety of context with general purpose. Aiso, for the usefulness of the language processor, we build an application system which can provide music play service based on context-awareness.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.8
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• pp.394-406
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• 2008

Even though context is the most important feature in context-aware systems, the existing requirements engineering cannot support methodology for elicitation and specification of contexts. In this paper, we propose a requirements elicitation method and a requirements specification method for context-aware systems. Our requirements elicitation method is a 6-stepped, incremental, and iterative process. At the beginning steps in the process, we identify the requirements for business logic. Afterwards, we gather the requirements for context logic, model contexts, and identify subsystems. For requirements specification, we suggest a context-aware use case diagram, a context diagram for context modeling, and a context-type-use-case-dependency diagram for the traceability of use cases on the change of context types. We also introduce a case study that we apply our approaches to a real system, and a qualitative evaluation of our approaches. Our study will help stakeholders to efficiently elicit requirements for context-aware systems and to specify them clearly.

• Journal of Korean Library and Information Science Society
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• v.43 no.1
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• pp.221-239
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• 2012

The information that has been created according to the complex environment and usage pattern of library user can provide context-aware information service through knowledge structuralization on whether it is a suitable situation for user. Accordingly, the development of a context model for defining the various contexts of library user and for the structuralization of interrelated context information is an essential requirement. This study examined the context concept and context modeling, and utilizing the concept of Activity Theory by Engestrom, the activity model of library user was designed as 1) subject, 2) object, 3) tools, 4) divison of labor, 5) community, and 6) rules. In addition, for the purpose of analyzing the context of library user, activity information was tracked to utilize the Shadow Tracking for observing and recording their forms, and the methodology of CAbAT (Context Analysis based on Activity Theory) was utilized for the collected activity information to analyze the user context model.

• Journal of the Korea Society of Computer and Information
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• v.16 no.6
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• pp.99-109
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• 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 KIISE:Computing Practices and Letters
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• v.12 no.4
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• pp.254-263
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• 2006

Ontology-based context models are widely used in ubiquitous computing environment because they have advantages in the acquisition of conceptual context through inferencing, context sharing, and context reusing. Among the benefits, inferencing enables context-aware applications to use conceptual contexts which cannot be acquired by sensors. However, inferencing causes processing delay and thus becomes the major obstacle to the implementation of context-aware applications. The delay becomes longer as the amount of contexts increases. In this paper, we propose a context pre-fetching method to reduce the size of contexts to be processed in a working memory in attempt to speed up inferencing. For this, we extend the query-tree method to identify contexts relevant to the queries of a context-aware application. Maintaining the pre-fetched contexts optimal in a working memory, the processing delay of inference reduces without the loss of the benefits of ontology-based context model. We apply the proposed scheme to our ubiquitous computing middleware, Active Surroundings, and demonstrate the performance enhancement by experiments.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.786-798
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• 2007

As we go about our daily lives, people often collect surrounding information and adapt to the situation. Computer development trends show that one wants computers to work like human beings, i.e. computers can sense its context and adapt corresponding to context changes. To implement this expectation, a context aware service layer is needed. In this layer, sensors capture its environment and send this information to the service center. Considering received information as its context, the service center seeks the suitable operation according to the context. Tills paper presents a context aware service which is applied in controlling air-conditioner. The air-conditioner includes sensors which are installed at some special positions in a room. Each of these sensors gathers comfort-influenced information like temperature, humidity and sends them to air-conditioner. The air-conditioner adapts its operation to the environment according to the sensed information. To control the air-conditioner effectively, we use a genetic algorithm which is suitable in adaptation issues. The simulation shows that the room condition can be maintained at a comfortable level by using context-aware services in the operation of the air-conditioning system.

• Journal of KIISE:Software and Applications
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• v.36 no.4
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• pp.283-290
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• 2009

Context-awareness is one of the key features of ubiquitous paradigm. A methodology that is specifying the relationships between the contexts and services needs to be developed to intelligently and sensitively deal with dynamic environment. The existing models on context-aware modeling are difficult to verify the correctness of models with respect to timeliness. In this paper we propose an approach which includes timing constraint in the relations of the context model, and verify its effectiveness using colored Petri-Net. Moreover, a context-modeling toolkit including context-awareness engine and simulator is developed to support agent-based context-aware service. The effectiveness of the proposed methodology is demonstrated using an example of Usilvercare.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.182-188
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• 2007

모바일 음악 재생 장치의 보급이 활성화 되면서 모바일 환경에서 음악을 즐기고자 하는 욕구가 확대되었다. 모바일 음악 재생 장치의 저장 공간이 확대되어 한번에 많은 곡을 보유하게 되었지만, 실제적으로 많은 곡 중에서 자신이 원하는 곡을 쉽게 찾을 수 있는 방법이 존재하지 않고 있다. 이런 문제들을 해결하기 위해 해당 음악 고유의 Metadata를 활용하여 쉽게 찾고자 하는 경향이 있지만, 현재까지는 단순한 사용자 인터페이스만 제공하고 있다. 각각의 음악은 음악 고유의 Context도 가지게 되며, 사용자의 음악 감상 로그에 의해 생성되는 개인화 Context 및 같은 음악을 즐기는 다른 사용자들에 의해 생성되는 Social Context등으로 하나의 음악과 관련된 Context가 증가되는 추세에 있다. 이와 같이 추가되는 Context들은 음악을 탐색하는데 있어 효과적인 수단이 제공되어야 하지만 모바일 음악 재생장치에 있는 음악 탐색 프로그램은 새롭게 추가되는 Context 에 의한 효과적으로 대응하지 못하고 있다. 이러한 문제점을 해결하기 위해서 모바일 장치에 Embedded Database Engine을 장착하여 동적 트리 생성/탐색을 통한 Context 기반 연관 음악 탐색 방법을 제안하게 되었다. 본 논문에서는 새롭게 고안된 음악 탐색 방법에 대하여 3가지 사항에 대해서 제시하였다. 첫째, 새로운 Context추가에 대한 동적 메뉴 추가 방법을 제시하였다. 둘째, 실제로 새롭게 추가된 사용자 인터페이스에 대해서 알아보았으며, 마지막으로 제시된 방법이 얼마나 효과적인가를 계산하여 일반화 하였다.