• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.73-83
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• 2008

This paper proposes an implementation of an orchestration service of web services, which work as context aware applications in Ubiquitous Computing. The proposed method alms to decrease the cost of adapting to the context changes. UC requires the context adaptation more than any other computing environments, and it works based on networks of various heterogeneous platforms. Web services on SOA could be one of the solutions for the requirements. This paper proposes the way how to implement an orchestration service of SOA to handle the context adaptation while keeping the performance high. We develops an implementation model of orchestration services of web services, and the model decreases the number of code lines of the orchestration service. This paper also shows a simple empirical study, and it also analyzes two different method implementing the polymorphism, overloading and overriding.

• Journal of the HCI Society of Korea
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• v.13 no.1
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• pp.21-28
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• 2018

The rapid increase of Sinlge-person household and the increase in the use of smart devices necessitate the context analysis of Sinlge-person household and specific design direction for Sinlge-person household products. Previous studies have analyzed the overall context of smart devices without distinguishing between Sinlge-person household and a household. However, since the number of family members, age distribution, and residential space are different in the case of Sinlge-person household, it is necessary to analyze the different behaviors of smart devices. Therefore, this study limits the use environment of smart device of Single-person household to the scope of investigation, and based on the theoretical background, defines the existing comprehensive context based on user's situation that lasts for a certain interval. For the concrete and empirical research results, Consolidated Flow Model was constructed through Contextual Task through user research. This shows the interaction characteristics such as the guarantee of physical space, efficiency, lifestyle reflection, and safety assurance of Single-person household.

• Journal of KIISE:Software and Applications
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• v.37 no.9
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• pp.676-686
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• 2010

An URC (Ubiquitous Robot Companion) is aimed for providing the best service according to situational information that it recognizes. In order to offer human-friendly and intelligent services, a robot middleware requires the technique to automate and control URC service processes, which are based on context-awareness. In this paper, we propose a context-aware workflow system to provide web services based URC services according to situational information. The proposed system offers a platform-independent command object model to control heterogeneous URCs, and supports web services based context-aware URC services. Therefore, the proposed system can increase the reliability of URC services in ubiquitous network environment, on which the diverse URC robots and platforms exist. And it can enhance the flexibility and adaptability of the functional and structural changes of URC systems.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.133-142
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• 2010

As the ubiquitous technology has penetrated into almost every aspect of modern life, the research of the security technology to solve the weakness of security in the ubiquitous environment is received much attention. Because, however, today's security systems are usually based on the fixed rules, many security systems can not handle diverse situations in the ubiquitous environment appropriately. Although many existing researches on context aware security service are based on ACL (Access Control List) or RBAC (Role Based Access Control), they have an overhead in the management of security policy and can not manipulate unexpected situations. Therefore, in this paper, we propose a context-aware security service providing multiple authentications and authorization from a security level which is decided dynamically in a context-aware environment using FCM (Fuzzy C-Means) clustering algorithm and Fuzzy Decision Tree. We show proposed model can solve typical conflict problems of RBAC system due to the fixed rules and improve overhead problem in the security policy management. We expect to apply the proposed model to the various applications using contextual information of the user such as healthcare system, rescue systems, and so on.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.58-73
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• 2015

In the IoT environment, context information is important to provide context service to the user. For this, collected data from devices such as sensors or actuators, converts to context information using the ontology. Because the existing ontologies designed for target service, if the user wants to change the service requirements, service condition, service environment or another service, overall ontology will be redesigned to the changed service. To overcome this difficulty, we propose the cross-vertical ontology model called the Generic Ontology Models(GOMs). It can define the user's desired services without regarding to place and situation. Also, we propose IoT service concept model that represents data flow of the IoT service and IoT service environment. Moreover, as the use case, we show that the proposed GOMs are able to provide the IoT service well.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.49-58
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• 2011

Augmented Reality(AR) assists human's cognitive ability through the information visualization by substantiating information about virtual situation. This technology is studied in a variety of ways including education, design, industry, and so on, by various supply of information devices equipped with cameras and display monitors. Since the most of the AR system depends on limited interaction that responds to the order from user, it can not reflect diverse real world situation. In this study, we suggest a knowledge based augmented reality system, which is composed of context awareness agent that provides recognized context information, along with knowledge based component that provides intelligent capability by utilizing domain knowledges. With this capability, the augmented object can generate dynamic model intelligently by reflecting context information, and can make the interaction possible among the multiple objects. We developed rule based context awareness system along with 3D model generation, and tested interaction among the augmented objects. And we suggest a framework that can provide a convenient way of developing augmented reality system for user.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.2
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• pp.91-101
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• 2008

For a friendly interaction between human and robot, emotional interchange has recently been more important. So many researchers who are investigating the emotion generation model tried to naturalize the robot's emotional state and to improve the usability of the model for the designer of the robot. And also the various emotion generation of the robot is needed to increase the believability of the robot. So in this paper we used the hybrid emotion generation architecture, and defined the generalized context input of emotion generation model for the designer to easily implement it to the robot. And we developed the personality and loyalty model based on the psychology for various emotion generation. Robot's personality is implemented with the emotional stability from Big-Five, and loyalty is made of familiarity generation, expression, and learning procedure which are based on the human-human social relationship such as balance theory and social exchange theory. We verify this emotion generation model by implementing it to the 'user calling and scheduling' scenario.

• Journal of Digital Convergence
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• v.10 no.1
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• pp.309-315
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• 2012

The dissemination of smartphones is being spread and supplementary services using smartphones are increasing and various as the Mobile network and device are developing rapidly, so smartphones that enables to provide a wide range of services is expected to receive the most attention. It makes users listen to music anytime, anywhere in real-time, use useful applications, and access to Internet to search for information. The service environment is changing on PC into Mobile due to the change of the circumstance mentioned above. these services are done by using just location information rather than other context, and users have to search services and use them. It is essential to have Context-aware technology for personalization recommendation services and the appropriate representation and definition of Context information for context-aware. Ontology is possible to represent knowledge freely and knowledge can be extended by inferring. In addition, design of the ontology model is needed according to the purposes of utilization. This paper used context-aware technologies to implement a user personalization recommendation service. It also defined the context through OWL modeling for user personalization recommendation service and used inference rules and inference engine for context reasoning.

• KIISE Transactions on Computing Practices
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• v.23 no.11
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• pp.641-649
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• 2017

As Internet of Things devices become pervasive, services improve to better assess the context and to alert other users to deal with emergencies. Such services use Internet of Things devices to detect the context around the user and promptly notify public institutions, hospitals or other parental users in emergencies. Most of these systems analyze an event when the value of the device is unchanged for a period of time or if it detects an abnormal value. However, just monitoring sensor values makes it difficult to accurately understand the context surrounding a user. Also if the device is inactive, it can not identify the context or provide services again. However, understanding the user requirements, services provided through other devices, information sent to other users lets, appropriate actions be taken. This paper, proposes a device search method and system based on a context-aware model that includes user demands. The proposed system analyzes the user's context and demands by using data collected from the internet of things devices. If user devices are inactive, they can recognize other devices by searching for other devices and providing services to users again. Through the proposed method, the user-centric services are provided. This method also analyzes and responds to requirements in various emergencies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1200-1206
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• 2009

In this paper, we propose an energy-efficient MAC(Medium Access Control) protocol for processing context information in ubiquitous sensor network environments. CASMAC(Context Aware Sensor MAC) use context information for energy-efficient operation and its operation principle is as follows. First, we make scenarios with possible prediction for CASMAC. And then we save setted context information in server. When event occur at specific sensor node, and then it send three times sample data to server. According to context information, server process sample data. If server process sample data with event, it receive continuous data from event occur node by a transmission request signal. And then server send data transmission stop signal to event occur node when it do not need to data. If server process sample data with no event, it have not reply. Through we make energy consumption tables and an energy consumption model, we simulate analysis of CASMAC performance. In a result, we gains about 5.7 percents energy reduction compared to SMAC.