• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.95-98
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• 2004

In this paper, we propose policy-based authentication framework which consists of policy server, CA and a policy language designed for ubiquitous environments. Using policies allows the security functionality to be modified without changing the implementation of the entities involved. Policy-based authentication framework needs to be very expressive but lightweight and easily extensible. We propose the feasibility of our policy language and policy-based authentication framework in ubiquitous-environment through a prototype and solve the problem that traditional framework have a simple registration and authentication to provide dynamic service.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.2
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• pp.1-9
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• 2010

The increasing popularity of mobile devices, such as cellular phones, smart phones, and PDAs, has fostered the need to recommend more effective information in ubiquitous environments. We propose the recommendation method for mobile contents service using contexts and prefetching in ubiquitous environment. The proposed method enables to find some relevant information to specific user's contexts and computing system contexts. The prefetching has been applied to recommend to user more effectively. Our proposed method makes more effective information recommendation. The proposed method is conceptually comprised of three main tasks. The first task is to build a prefetching zone based on user's current contexts. The second task is to extract candidate information for each user's contexts. The final task is prefetch the information considering mobile device's resource. We describe a new recommendation.

• Korean Journal of Computational Design and Engineering
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• v.10 no.6
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• pp.402-411
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• 2005

Context-aware engineering services in ubiquitous environments are emerging as a viable alternative to traditional engineering services. Most of the previous approaches are computer-centered rather than human-centered. In this paper, we present a Ubiquitous and Context-Aware computing Framework for collaborative virtual Engineering $(U-CAF\acute{E})$ services. The proposed approach utilizes BPEL-based (Business Process Execution Language) process templates for engineering service orchestration and choreography and adopts semantic web-based context-awareness for providing human-centered engineering services. The paper discusses how to utilize engineering contexts and share this knowledge in support of collaborative virtual engineering services and service interfaces. The paper also discusses how Web services and JINI (Java Intelligent Network Infrastructure) services are utilized to support engineering service federations and seamless Interactions among persons, devices, and various kinds of engineering services.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.4
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• pp.611-617
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• 2008

In ubiquitous environments, the content adaptable services can be dynamically provided to adapt the frequent changes of contexts. These services have common things that the kinds of context factors are limited to ubiquitous environment, though the contexts are flexible. To reuse service architecture can be reasonable for effective adaptable service. In this paper, we design a software architecture with product line techniques for content adaptable applications in ubiquitous environment. Description of product line is to define variation points and their variants, to find out the dependencies between them and to keep the model based architecture, their alternatives.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.239-248
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• 2006

Current context-aware applications In ubiquitous computing environments make the assumption that the context they are dealing with is correct. However, in reality, both sensed and interpreted context informations are often uncertain or imperfect. In this paper, we propose a probability extension model to ontology-based model for rep resenting uncertain contexts and use Bayesian networks to resolve about uncertainty of context informations. The proposed model can support the development and operation of various context-aware services, which are required in the ubiquitous computing environment.

• Educational Technology International
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• v.8 no.2
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• pp.1-19
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• 2007

This study is to analyze the implications of effective learning in a ubiquitous environment. Research proceeded according to the multiple case study analysis method. This paper is one result of the Korean case study to examine the effectiveness of and satisfaction with u-learning. We will introduce necessary conditions for effective learning in a ubiquitous environment. Each condition was elicited through the case study, and the analyzing framework was classified into hardware related to infra structure; software such as learning contents, teaching-learning activity and support, and class management; human-ware related to learner and teacher; system-ware as an education system, and administrative supporting.

• Journal of KIISE:Software and Applications
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• v.37 no.6
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• pp.430-445
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• 2010

Effective service description and modeling methodologies are essential for dynamic service composition to provide autonomous services for users in ubiquitous computing environments. In our previous research, we proposed a 'u-Service' as an abstract and structured concept for operations of devices in ubiquitous environments. In addition, we established the mechanism to structure u-Services as an ontology and the description specification to represent attributes of u-Services. However, it did not provide enough methods or standards to analyze and evaluate the effectiveness of the u-Service ontology in the design time. Since existing quality models for software products or computing systems cannot consider characteristics of ubiquitous services, they are not suitable for ubiquitous service ontology. Therefore, in this paper, we propose a quality evaluation model to design and modeling a good ubiquitous service ontology, based on our u-Service ontology building process. We extract modeling goals and evaluation indicators according to characteristics of ubiquitous service ontology, and establish quality metrics to quantify each quality sub-characteristics. The experiment result of the proposed quality evaluation model for u-Service ontologies which are constructed for our previous works shows that we can analyze the design of ubiquitous service ontology from various angles, and indicate recommendations for improvement.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.47-65
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• 2011

Business organizations are asked to create new business models utilizing current technological innovations such as ubiquitous computing technology for developing new domains of business to obtain a competitive advantage and achieve a sustainable development. This study was focused on the processes for developing new and practical business models. The purpose of this study was to propose ubiquitous sport business modeling processes from the modeling framework. In particular, this study focused on developing new, pragmatic, and effective sport business models, and this new type of business is defined as 'u-sport.' For design the business model, extensive literature reviews and case studies were conducted for benchmarking the cases and expert group review was conducted for developing u-sport business model framework. The suggested business modeling processes in this study were consisted of four phases; 1) organization strategy level setting phase, 2) business strategy level setting phase, 3) business structure level setting phase, and 4) service level setting phase. The modeling processes were verified to adapt ubiquitous sport business. This designing and modeling process is expected to play a significant role on enhancing the technology-based business environments as the process mainly focuses on the service and consumer oriented approach rather than technology and suppliers oriented approach. In conclusion, establishing sport business models by adapting the service modeling process will deliver an exponential growth and development of future ubiquitous based industry.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.4
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• pp.61-75
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• 2007

In ubiquitous computing, shared environments are required to adapt to people intelligently. Based on information about user preferences, the shared environments should be adjusted so that all users in a group are satisfied as possible. Although many group recommender systems have been proposed to obtain this purpose, they only consider average and misery. However, a broad range of philosophical approaches suggest that high inequality reduces social agreeability, and consequently causes users' dissatisfactions. In this paper, we propose social welfare functions, which consider inequalities in users' preferences, as alternative aggregation functions to achieve a social agreeability. Using an example in a previous work[7], we demonstrate the effectiveness of proposed welfare functions as socially agreeable aggregate functions in group recommender systems.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.50.3-50
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• 2002

Our living spaces are becoming increasingly populated with infinite numbers of intelligent embedded agents we are interacting with. in ubiquitous computing environments the aim is to support the occupants during their everyday lives and enhance their living conditions. In this paper we introduce such an environment, the iDorm, which has arisen from our work in careAgents, a project supported by the UK-Korean S&T collaboration fund and the EU's Disappearing Computer Initiative eGadgets project We discuss the research challenges involved, particularly those relating to intelligently associating and configuring large numbers of embedded agents. The paper presents an intelligent association sys...