• The KIPS Transactions:PartD
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• v.14D no.1 s.111
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• pp.139-144
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• 2007

In seeking to improve the workload efficiency and inference capability of context-aware systems, we propose a new framework for an advanced teaming mechanism that uses improved bath propagation (BP) algorithm. Even though a learning mechanism is one of the most important parts in a context-aware system, the existing algorithms focused on facilitating systems by elaborating the learning mechanism with user's context information are rare. BP is the most adaptable algorithm for learning mechanism of context-aware systems. By using the improved BP algorithm, the framework we proposed drastically improves the inference capability so that the overall performance is far better than other systems. Also, using the special system cache, the framework manages the workload efficiently. Experiments show that there is an obvious improvement in overall performanre of the context-awareness systems using the proposed framework.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.64-83
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• 2012

The number of smart phone users is rapidly growing due to recent increase in wireless Internet usage, development of a wide variety of applications, and activation of M2M (Machine to machine) services. Although the smart phone offers benefits of mobility and convenience, it also has serious security problems. To utilize M2M services in the smart phone, a flexible integrated authentication and access control facility is an essential requirement. To solve these problems, we propose a context-aware single sign-on and access control system that uses context-awareness, integrated authentication, access control, and an OSGi service platform in the smart phone environment. In addition, we recommend Fuzzy Logic and MAUT (Multi-Attribute Utility Theory) in handling diverse contexts properly as well as in determining the appropriate security level. We also propose a security system whose properties are flexible and convenient through a typical scenario in the smart phone environment. The proposed context-aware security system can provide a flexible, secure and seamless security service by adopting diverse contexts in the smart phone environment.

• Journal of Service Research and Studies
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• v.4 no.1
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• pp.49-59
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• 2014

Context-aware computing is an emerging paradigm to achieve ubiquitous computing environments by enabling computer systems to understand their situational contexts. A context-aware system uses context to provide relevant information and services to the user depending on the user's task. In this paper, we propose an ontology-based context-aware modeling methodology that transmits low-level contexts acquired by directly accessing various sensors in the physical environments to high-level contexts. With these high-level contexts, context-aware application can provides proactive and intelligent services using ECA (Event-Condition-Action) rules. We implemented a home robot service in smart office environment.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.415-426
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• 2006

The essential characteristic of ubiquitous is context-awareness, and that means ubiquitous computing can automatically process the data that change according to space and time, without users' intervention. However, in circumstance of context awareness, since location information is able to be collected without users' clear approval, users cannot control their location information completely. These problems can cause privacy issue when users access their location information. Therefore, it is important to construct the location information system, which decides to release the information considering privacy under the condition such as location, users' situation, and people who demand information. Therefore, in order to intercept an outflow information and provide securely location-based information, this paper suggests a new system based CS-RBAC with the existing LBS, which responds sensitively as customer's situation. Moreover, it accommodates a merit of PCP reflecting user's preference constructively. Also, through privacy weight, it makes information not only decide to providing information, but endow 'grade'. By this method, users' data can be protected safely with foundation of 'Role' in context-aware circumstance.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.102-103
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• 2010

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.960-967
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• 2006

Mobile communication is evolving toward next generation system that is capable to provide ubiquitous human-centric services with giving no restriction on time and location. In particular, context-awareness will be realized using various sensors and devices and related technologies under the ubiquitous Next Generation (NG) mobile communications environment where user's demand and surrounding context are changing dynamically. By such context awareness, context aware service which provides best suitable services for a user by analyzing user's needs and situational information, will be one of the promising NG mobile services. In this article, we propose NG mobile service environment with focusing on generic service traffic flows supported by the NG service platform which gives various means of connecting users and service providers. Then, we propose evolutional phases of context-aware services based on ranges of context information and evolutional trend of telecommunication technologies and networking environment in NG mobile service environment.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.6
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• pp.378-387
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• 2007

To enhancing the exercise effect, exercise management systems are introduced and generally used. They create the proper exercise program through exercise prescription after determining the personal body status. When the exercise programs are created, they will consider $2weeks{\sim}3months$ period. And, existing exercise programs cannot respect with personal exercise habits or exercise period which are changing variedly. If exercise period is long, it can be caused inappropriate exercise about user current status. To solve these problems in legacy systems, this paper proposes a Context Aware Exercise Model (CAEM) to provide the exercise program considering the user context. Also, we implemented that as Intelligent Fitness Guide (IFG) System. The IFG system is selectively received necessary measurement values as input values according to user's context. If exercise kinds, frequency and strength of user are changing, that system creates the exercise program through exercise optimization algorithm and exercise knowledge base. As IFG is providing the exercise program in a real time, it can be managed the effective exercise according to user context.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.239-247
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• 2014

Ubiquitous computing environment, as a new paradigm of the digital information era, has been introduced to respond to rapid changes in society and culture. Today, technology research around the world competes for the preoccupancy of the core technology as well as the development of technology for providing context aware system more intelligent, more sophisticated. Research in recent is underway the implementation of intelligent provisioning system using the ontology. Erstwhile provisioning system did not providing a personalized service that provides the service after context aware. Accordingly, there is a need for studies of intelligent context aware provisioning technique considering environments and context necessary to user. In this paper, in order to provide a service that is optimized for the needs of the user, propose an ontology-based intelligent provisioning service method taking into account the usage patterns and the context of the user. The proposed system is recognized the status of the user and demonstrated a process of reasoning techniques for fit service. And it is possible to the expansion of intelligence.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.579-582
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• 2009

With the aid of the increasing interests of Context-aware Augmented Reality Agent (AR Agent), various researches of AR Agent have been performed to explore the possibility of the agent as novel interface and the entity responding autonomously by user's input. However, in previous works, AR Agents are lack of specific method for using various contextual information. To revolve around those problems, we propose the Behavior Generation System for Context-aware AR Agent using layered architecture. Based on Belief-Desire-Intention (BDI) model and Hierarchical Task Network (HTN) searching, the sequence of agent behavior has been selected in behavior planning layer. Then, the agent evaluates appropriateness of behaviors using previous behavior and the type of input before activation. This behavior generation system can be applied for edutainment, game, and assistant agent, which need intuitive and effective behaviors to convey information. Through this research, we expect that the Context-aware AR Agent could support for not only information delivery, but also the capability of effective communication for user.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.253-255
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• 2015

In a variety of network environments, the provision of context-aware services, it is difficult to integrate and share because of the heterogeneity problem between distributed data. This paper proposes the integration model using the ontology as a method for solving the above. This uses an ontology to integrate the context-aware informations that are collected. The ontology is generated by the acquisition, semantic analysis and inference of the metadata of the context-aware information. This is the basis of the analysis and analysis of the additional system. Accordingly, this paper studies ways to create an ontology and apply them. The advantage of the proposed scheme can be used without modifying the existing tools, it is possible to easily perform the expansion and consolidation of the system.