• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.145-157
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• 2009

In recent years, there have been several researches applying workflow technologies for service automation on ubiquitous computing environments. However, most context-aware workflow languages have difficulties in supporting composite workflows composed of single workflows, because these languages are still in its early stage and they only provide single workflow services to their users. This paper introduces CAWL, which is a context-aware workflow language. CAWL is for describing individual service workflows to make integrated service workflows. By using CAWL, service developers are able to reuse existing workflows to develop new context-aware workflow services. Therefore, development efforts and time can be saved and workflow resusability also increased. CAWL is expected to make it easy to develop applications related to context-aware workflow services on ubiquitous computing environments.

• 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 the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.355-364
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• 2005

Ubiquitous environment can be supported by various service on networked appliance, sensors and devices. In home network and telematics, open service gateway is widely used for ubiquitous environment and Present environment for service installation, deployment and execution. Service gateway is a middle layer which is located between service and various devices in ubiquitous environment and offers a unique opportunity for pervasive computing as a potential framework for achieving interoperability between various sensors, home appliances. and networked devices. In ubiquitous environments, these services must support the mobility among service gateway because users and devices has a mobility characteristic. However the OSGi framework supports only a remote installation of a bundle, which is a unit that installs and deploys services. This paper develops a system that can manage bundles for supporting this dynamic bundle's mobility between service gateway. This system we are proposing implements a bundle form which can perform in an OSGi framework as well as manage the mobile services. As a result, mobility in a ubiquitous computing environment will be supported more efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.439-442
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• 2014

The previous wearable computing researches have been taken the deficiency of global view about ubiquitous integration. They have approached the skewed directions and approaches for the wearable ubiquitous computing. Therefore we propose a more advanced global architecture model and a general service cycle. This paper firstly proposes an architecture design of computing life cycles in digital garment environments. Then it also provides the process cycles for supporting general services in digital garment applications. Finally, we present the important design consideration issues for implementing a digital garment system.

• Journal of information and communication convergence engineering
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• v.6 no.1
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• pp.86-90
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• 2008

In this paper, I have presented a new approach which can track moving objects in unknown environments. This scheme is important in providing a computationally feasible alternative to complete enumeration of JPDA which is intractable. I have proved that given an artificial measurement and track's configuration, proposed scheme converges to a proper plot in a finite number of iterations. In this light, even if the performance is enhanced by using the relaxation, we also note that the difficulty in tuning the parameters of the relaxation scheme is critical aspect of this suggestion.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.1
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• pp.45-50
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• 2005

Recently, ubiquitous Computing is being actively researched and one of the main technology in ubiquitous computing environments is recognized as RFID system. The RFID system has much benefits but simultaneously has some problems such as user's privacy violation. Therefore, in this paper, we analyze the privacy problems of previous methods and propose more secure and effective authentication method to protect user's privacy. The proposed protocol is secure against replay attack, spoofing attack and tracking by an attacker.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.170-174
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• 2005

It is projected that, in a near future, our living environment will transform into the ubiquitous computing environment. Many scenarios and projections of how humans will actually interact with such an environment to receive various services have been made, but most of them remain to be untested ideas on paper without implementation. In this paper, we propose to use P-VoT, a component based interactive authoring toolkit for virtual environments, to quickly build a virtual ubiquitous computing environment.

• ETRI Journal
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• v.29 no.5
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• pp.545-558
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• 2007

This paper presents an efficient semantic service discovery scheme called UbiSearch for a large-scale ubiquitous computing environment. A semantic service discovery network in the semantic vector space is proposed where services that are semantically close to each other are mapped to nearby positions so that the similar services are registered in a cluster of resolvers. Using this mapping technique, the search space for a query is efficiently confined within a minimized cluster region while maintaining high accuracy in comparison to the centralized scheme. The proposed semantic service discovery network provides a number of novel features to evenly distribute service indexes to the resolvers and reduce the number of resolvers to visit. Our simulation study shows that UbiSearch provides good semantic searchability as compared to the centralized indexing system. At the same time, it supports scalable semantic queries with low communication overhead, balanced load distribution among resolvers for service registration and query processing, and personalized semantic matching.

• International Journal of Internet, Broadcasting and Communication
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• v.5 no.1
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• pp.9-13
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• 2013

This paper presents the concepts of ubiquitous computing technology to construct a ubiquitous learning environment that enables learning to take place anywhere at any time. This ubiquitous learning environment is described as an environment that supports students' learning using digital media in geographically distributed environments. The u-learning model is a web-based e-learning system that could enable learners to acquire knowledge and skills through interaction between them and the ubiquitous learning environment. Students are allowed to be in an environment of their interest. The communication between devices and the embedded computers in the environment allows learner to learn while they are moving, hence, attaching them to their learning environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1569-1584
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• 2013

Ubiquitous interaction in a pervasive environment is the main attribute of smart spaces. Pervasive systems are weaving themselves in our daily life, making it possible to collect user information invisibly, in an unobtrusive manner by known and even unknown parties. Huge number of interactions between users and pervasive devices necessitate a comprehensive trust model which unifies different trust factors like context, recommendation, and history to calculate the trust level of each party precisely. Trusted computing enables effective solutions to verify the trustworthiness of computing platforms. In this paper, we elaborate Unified Trust Model (UTM) which calculates entity's trustworthiness based on history, recommendation, context and platform integrity measurement, and formally use these factors in trustworthiness calculation. We evaluate UTM behaviour by simulating in different scenario experiments using a Trust and Reputation Models Simulator for Wireless Sensor Networks. We show that UTM offers responsive behaviour and can be used effectively in the low interaction environments.