• Journal of Information Technology Services
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• v.9 no.1
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• pp.113-125
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• 2010

Recently, a smart space with Ubiquitous Environment is expanding rapidly due to the development of Ubiquitous Sensor Network. Therefore, more appropriate and intelligent services of the context awareness system is being required. The previous context awareness system can provide a service to the user through the inference only on the current situation. But, it does not handle certain situation properly when the system provides abnormal result. Also it does not have any proper method of generating reliable semantic data from sensed raw data. In this paper, we are trying to solve the problems as the following approaches. First, the system recognizes abnormal result and corrects it by learning feedback from the user. Second, we suggest a method of converting sensed data into more reliable semantic data. Third, we build the system based on an Ontological context model that is capable of interoperability and reusability. Therefore, the context awareness system of our study can enhance the previous system that can generate more reliable context data, can provide more effective inference method, and can provide more intelligent system structure.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.137-143
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• 2008

In ubiquitous environment the multi-agent system is effective for providing intelligent services. In this paper we introduce a new scheduling service model for improving the communication performance in the multi-agent system. It is achieved by assigning a priority to the message according to the weight of formalized ACL message and the number of messages exchanged between the agents. An experiment reveals that the proposed approach allows smaller processing time per message and turnaround time than the scheduling with the existing JADE platform. Moreover, the proposed scheme allows a scalable messaging system.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.51-54
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• 2008

유비쿼터스도시(u-City) 에서 제공할 서비스 즉, u-City서비스를 실제로 구현하기 위해서 사용되는 기술을 u-City 기술이라고 할 수 있다 본 논문에서는 u-City서비스, u-City 기반시설 그리고 u-City 기술들 간의 관계를 명확히 설명하기 위한 도구로서 u-City 기술 참조모델을 정의하였다. 이러한 참조모델을 사용함으로써 u-City 구축자, 서비스 제공자, 운영자, 이용자 등 여러 u-City 참여자들이 공감할 수 있는 서비스-기술 연계 모델을 제시하였으며 향후 u-IT 세부 기술이 발전하고 새로운 u-City 서비스가 추가되어도 이를 원활히 수용할 수 있도록 하였다.

• Journal of Advanced Information Technology and Convergence
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• v.10 no.2
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• pp.73-81
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• 2020

The number of mobile devices roaming into a ubiquitous city (u-city) continues to rise as wireless systems have been widely deployed. The number of mobile devices also varies with time, and they tend to frequently change their locations. In addition, the available wireless access networks may belong to different domains, administrations, management, and internet service providers (ISPs). A fusion of overlapping heterogeneous wireless access networks (e.g., WiMax, Wi-Fi, LTE, etc.) serves the u-city in order to reach different coverage. In this context, technical challenges arise in mobility management for heterogeneous networks to realize their potential coverage and capacity benefits. This paper deals with the analysis of a decentralized mobility management support for u-City wireless network infrastructure. This scheme takes advantage of the features of the fully-distributed model of networked-based mobility management protocol to alleviate and realize the ubiquitous requirements of a u-City.

• Journal of Digital Contents Society
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• v.9 no.3
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• pp.509-516
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• 2008

We propose the Hybrid Rendering model to support multi-resolution for computer graphics. LOD method for computer graphics system considering performance of device environment and end-user preference usually adopts mesh resolution, mipmap in texture rendering, or oct-tree data structure in ray tracing. The hybrid rendering model, as a local shading model combining Gouraud shading model and a flat shading model, applies a proper shading method to each of polygons consisting of an object. This method can be an effective alternative to reduce real-time rendering time so that it can be utilized in real time adaptive service of computer graphic contents among various device environments under ubiquitous environments.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.85-90
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• 2012

In Korea, livestock has grown into the most value-added business in the agricultural and forest industry. But due to the recent outbreak of deadly infectious diseases such as foot-and-mount disease and avian influenza (AI), the demand for IT-enabled cutting-edge management system is getting stronger. As for humans, pilot projects and researches concerning U-healthcare have been carried out since early 2000. So this study explored the current progress of U-healthcare introduction, and suggested the strategies to develop technologies of collecting, processing, and utilizing information; to apply elements for a service model development and prioritization; to provide policy and institutional support. Therefore it is expected to vitalize the livestock U-healthcare in the future through continuous study based on these results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1058-1065
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• 2010

In the recent, the importance of ubiquitous-related technique is increased as many companies and researchers make an effort to create a new service model using ubiquitous computing and network technologies. Especially, the research of indoor location recognition has gained a lot of interest because it is a critical component for supporting ubiquitous services. Nevertheless, the simulation tool for indoor location recognition hardly has studied compared to their importance. In this paper, we propose a Ptolemy-based simulator over UWB channel that provides short-range and high-bandwidth communication. Finally, we conduct experiments using the proposed simulator and analyze the performance of various location recognition algorithms.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.169-176
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• 2009

Many researches and projects are implemented about u-IT according to changes of ubiquitous environments in the world. Especially, there are benefits to raise lifestyle and we can develop industry by applying ubiquitous regionally. Also it makes citizen feel comfortable directly. There are many projects to regionally adopt ubiquitous services like u-City model for getting this advantages. RFID technology must be suited to each environment because each RFID tag has different characteristics according to frequency band. We need to integrate bands of RFID to overcome limitations and provide more detail information and services. In this study, we develop the dual band RFID Manager needed adopting u-Zone service for both 13.56MHz and 2.45GHz. The RFID Manager, application software for base station of u-Zone, delivers the information from readers to integrated u-Zone server system.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1351-1358
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• 2013

This paper aims to study the effects of quality of u-City public service on customer satisfaction in the Korea and is summarized as follows. First, we propose a model for assessing customer's satisfaction on u-City public services. The model comprises of information system (IS) quality, information quality, service quality and publicity. For verifying a model, a statistical study by SPSS 12.0 and AMOS 16.0 has been performed. Second, it is shown from the analysis that information system (IS) quality, information quality and publicity have a positive effect on customer satisfaction. while service quality does not. Last, the study shows that u-City public service enables any citizen to connect to necessary service in anytime and anywhere.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.191-203
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• 2009

To provide dynamic services for users in ubiquitous computing environments by considering context in real-time, in our previous work we proposed Metaservice concept, the description specification and the process for building a Metaservice library. However, our previous process generates separated models - UML, OWL, OWL-S based models - from each step, so it did not provide the established method for translation between models. Moreover, it premises aid of experts in various ontology languages, ontology editing tools and the proposed Metaservice specification. In this paper, we design the translation process from domain ontology in OWL to Metaservice Library in OWL-S and develop a visual tool in order to enable non-experts to generate consistent models and to construct a Metaservice library. The purpose of the Metaservice Library translation process is to maintain consistency in all models and to automatically generate OWL-S code for Metaservice library by integrating existing OWL model and Metaservice model.