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Publications (7)0 Total impact

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    ABSTRACT: In order to provide context-aware services, context modeling is one of the most important tasks. Ontology has been widely accepted for the context modeling but it brings some overheads in the process of reasoning large-scale and dynamic information. In mobile networks, especially, ontology should be verified to be applicable for Context-aware Services since real-time responsiveness for large scale moving users is highly required to be guaranteed. This paper proposes an efficient context model to overcome the limitation of ontology. For the purpose, we design a conceptual context model and compare the processing time of the context-aware mobile service system implying the three different context modeling approaches ontology, database, and proposed hybrid modeling. As the result of performance evaluations, the proposed hybrid model shows faster processing time among them and lesser affected by the major metrics of mobile services changeability and number of users than the two existing models. Based on the experimental results, we expect that the proposed hybrid model is very useful and efficient for fast responsiveness to support Context-aware Services for large scale users in mobile networks.
    Consumer Communications and Networking Conference (CCNC), 2010 7th IEEE; 02/2010
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    ABSTRACT: Personalization has a key role to play in making a ubiquitous computing system more usable to the end user. Our goal is to provide the end user with two-step personalization services. To do this, we propose the personalized situation model consisted of user behavior and user preferences models. The former is to set up a weighted list of useful services according to user behavior patterns of current situation. The latter is to set up a weighted list of specific contents according to the service selected by a user. That is to say, two-step personalization services are consisted of service recommendation step and contents recommendation step. As a result, if user selected TV service among service categories to be recommended at the first step, it should match a user's desired TV programs and recommend TV programs with high user preference at the second step.
    Advanced Communication Technology, 2009. ICACT 2009. 11th International Conference on; 03/2009
  • Aekyung Moon, Yoo-Mi Park, Young-Il Choi
    ICSOFT 2009 - Proceedings of the 4th International Conference on Software and Data Technologies, Volume 2, Sofia, Bulgaria, July 26-29, 2009; 01/2009
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    ABSTRACT: This paper reviews the Parlay X and proposes SIP multimedia session control mechanism which is able to be implemented over IMS using Extended Call Control APIs of Parlay X. Parlay X is one of the industrial standards of Open API in the telecommunication to open network resources and capabilities to third party service providers. In this paper, SIP session control mechanism is described by depicting call flows of basic and essential session handling methods including session initiation, transfer, restoration, and termination. We also show how easy Parlay X Extended Call Control APIs can be used for the purpose of complicated calls handling in the IT applications. To verify feasibility of the blended services based on convergence of telecommunication and internet with regard to performance, we accomplish experimental performance of Extended Call Control APIs from IT application through open service gateway. We show Open API could be applied to next generation network based on IMS without serious degradation of the network performance.
    The Journal of Korea Information and Communications Society. 01/2008; 33(12B).
  • Aekyung Moon, Young-Il Choi, Byung-Sun Lee
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    ABSTRACT: With the advent of ubiquitous computing environments, a significant amount of work has been devoted to context-aware. We proposed the context-aware user model, which is aware of its userpsilas situation and recommends personalized services based on this information. This paper focuses on how our algorithms can be applied to a variety of environment easily and evolve user model without previously known information since the concerns of privacy. The proposed user model consists of context and action pairs. Using context-aware user model, we learn user behavior pattern in the situation, which is captured by union of contexts according to current environments. In order that our user model applies to new environment, only context profiles are required to be defined without any modification to model. Moreover we evolved user model through interactions between users and mobile devices using learning mechanism. Finally, we evaluate the precision of proposed approach using simulation with data sets of UCI depository.
    Third IEEE International Conference on Digital Information Management (ICDIM), November 13-16, 2008, London, UK, Proceedings; 01/2008
  • Jong-choul Yim, Young-il Choi, Byung-sun Lee
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    ABSTRACT: One of the key factors of next generation networks (NGN) is opening up the capabilities of the network. Parlay Group leads the standard, so called Parlay/OSA API, to open up the networks by defining, establishing, and supporting a common industry-standard APIs. Parlay Group also specifies the Parlay Web services API, also known as Parlay X API, which is much simpler than Parlay/OSA API to enable IT developers to use it without network expertise. One of Parlay X API is third party call (TPC) API which provides simple API for the purpose of creating and managing the call by the third party. IMS was devised originally by 3GPP for mobile networks, but currently it is accepted widely as a reference model of NGN even in fixed network domains. IMS has an interface called ISC to open the network capabilities. This paper overviews how Parlay X Web services can be supported in IMS in an architectural perspective, and discusses how the third party call can be implemented in IMS using Parlay X TPC APIs
    Advanced Communication Technology, 2006. ICACT 2006. The 8th International Conference; 03/2006
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    Yoo-mi Park, Young-il Choi, Sang-ha Kim
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    ABSTRACT: Open API in telecommunication is a service control technologies and is a set of abstract standard operations which can provide capabilities to access telecom network for the 3rd party service provider in a secure manner. This paper describes presence-based call reservation service which is a case study of converged service with open API on the Web-service architecture in broadband converged network. The presence-based call reservation service could provide the enterprise with combining capabilities of accessing network resources and manipulating enterprise data resources. We also propose a simple control mechanism for realization of this service with open API on the Web-service architecture
    Advanced Communication Technology, 2006. ICACT 2006. The 8th International Conference; 03/2006