• KIISE Transactions on Computing Practices
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• v.21 no.12
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• pp.756-761
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• 2015

With the emergence of the Internet-of-Things (IoT) paradigm, there is a growing demand for personalized services using IoT contexts acquired from heterogeneous IoT devices. However, due to the mismatch between IoT context exchange schemes of context-aware services and IoT devices, IoT applications can acquire IoT contexts only from IoT devices that support the same IoT context exchange schemes. In this paper, we propose dynamic methods to mediate those mismatches on the IoT context exchange schemes. With the proposed mediation methods, context-aware services can collect IoT contexts from heterogeneous IoT devices without considering their IoT context exchange schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.331-332
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• 2016

In the IoT environment, The mass IoT data can be collected in a variety of IoT devices. Due to mass IoT data, the services for data processing and providing are needed that fit user requirements. So we propose the design of IoT data management system based on ontology using context information.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.129-137
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• 2015

Various personalized services are provided based on user context these days, and IoT(Internet of Things) devices provides effective ways to collect user context. For example, user's activity such as walking steps, calories, and sleeping hours can be collected using smart activity tracker. Smart scale can sense change of user's weight or body fat percentage. However, these services are independent to each other and not easy to make them collaborate. Many standard bodies are working on the documents for this issue, but due to diversity of IoT use case scenarios, it seems that multiple IoT technologies co-exist for the time being. This paper propose a framework to collaborate heterogeneous IoT services. The proposed framework provides methods to build application for heterogeneous IoT devices and user context management in more intuitive way using HTTP. To improve compatibility and usability, gathered user contexts are based on MPEG-UD. Implementation of framework and service with real-world devices are also presented.

• 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.24 no.3
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• pp.159-166
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• 2019

The collection and manipulation of Internet of Things (IoT) data is increasing at a fast pace and its importance is recognized in every sector of our society. For efficient utilization of IoT data, the vast and varied IoT data needs to be reliable and meaningful. In this paper, we propose an IoT framework to realize this need. The IoT framework is based on a four layer IoT architecture onto which context aware computing technology is applied. If the collected IoT data is unreliable it cannot be used for its intended purpose and the whole service using the data must be abandoned. In this paper, we include techniques to remove uncertainty in the early stage of IoT data capture and collection resulting in reliable data. Since the data coming out of the various IoT devices have different formats, it is important to convert them into a standard format before further processing, We propose the RDF format to be the standard format for all IoT data. In addition, it is not feasible to process all captured Iot data from the sensor devices. In order to decide which data to process and understand, we propose to use contexts and reasoning based on these contexts. For reasoning, we propose to use standard AI and statistical techniques. We also propose an experiment environment that can be used to develop an IoT application to realize the IoT framework.

• Journal of Korea Multimedia Society
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• v.19 no.7
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• pp.1166-1178
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• 2016

In Internet of Things (IoT) environments, billions of interconnected devices and multimedia sensors generate a huge amount of multimedia traffic. Since the environment are in general deployed as a server-centric architecture wireless sensor networks could be bottlenecks between IoT gateways and IoT devices. The bottleneck causes high power consumption of the device and triggers very heavy network overload by transmission of sensing data. The deterioration could decrease the quality of multimedia streaming service due to delay, loss, and waste of device power. Thus, in this paper, we propose a context-based adaptive multimedia streaming scheme to support enhanced QoS and low power consumption in IoT environments. The goal of the scheme is to increase quality score per voltage of the streaming service, given an adaptation algorithm with context that are classified network and hardware such as throughput, RTT, and CPU usage. From the both context, the quality score per voltage is used in the comparison of a only network context-based adaptive multimedia streaming scheme, a fixed multimedia streaming and our scheme. As a result, we achieves a high improvement that means the quality score per voltage is increased up to about 4, especially in case of resolution change.

• Journal of the HCI Society of Korea
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• v.12 no.4
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• pp.57-64
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• 2017

The user-centered design paradigm shift and the emergence of user-experience design have also increased the importance of user experience with products and services in specific spaces. In addition, with the advent of IoT services, new changes in the future work environment are expected. This study aims to propose a new user experience design considering the context of future work space. First of all, we examined the concept and nature of IoT, and defined various factors that affect the future work environment and grasped the relation of each element. Next, user research in the current work environment was conducted to identify the context that affects the behavior of users in various types of work environments, and to insight the possibility of a new user experience in the future work environment. Based on the above analysis and insights, various context models for a new future work environment were constructed, and UX models and UX scenarios and alternatives were presented. This study will contribute to the diversity of UX design research by expanding the viewpoint of UX design from device to space and context, and it will contribute to the collaborative research with space design and service design, also interdisciplinary research with IoT service related field.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.217-223
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• 2017

With the development of sensor networks and Internet of Things (IoT) technology, personalized context information has been collected and customized services can be provided to related users. Currently, the context information system is at the level of analyzing and recognizing user specific behavioral characteristics and generating events.In the IoT environment, IoT products themselves should provide the required services with minimal user intervention, rather than acting for a specific purpose. In this paper, to minimize the user intervention in the IoT environment, we implemented an automatic attendance recognition system using context information from the ECG based on beacon. Environment of provided specific Context information, we compared and analyzed the degree of user intervention among the authentication method using ECG sensor in this paper and the existing authentication method. As a result of the analysis, we confirmed that the system implemented in this paper minimizes user intervention.

• Journal of Service Research and Studies
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• v.2 no.2
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• pp.91-98
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• 2012

The emergence of new types of embedded computing devices and developments in wireless networking are broadening the domain of computing from the work place and home office to other facets of everyday life. This trend is expected to lead to a proliferation of Internet of Things (IoT) environments, in which inexpensive and interconnected computing devices are capable of supporting users in a range of tasks. Context-aware computing is a key source to develop such smart services. However, there are many challenges to enable services to be smart; Heterogeneous Computing Environments, Resource Limitations, Large Amount of Data Produced, and Different Requirements for Context Interpretation. Because of these challenges, there are difficulties in providing smart service by utilizing IoT devices. Currently, many researchers are conducting researches on mobile-computing based smart service development and provisioning and network infrastructure for interconnected IoT devices. Still, there are some limitations on developing core technologies for IoT computing based smart service development. In order to remedy this situation, this thesis presents a reusable framework that provides unique and noble features which are required in developing advanced context-aware IoT applications.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.29-44
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• 2014

To provide context aware service, certain phenomena and situation information of the user should be detecting and monitoring using sensors. But, the sensor data has heterogeneity about system, syntax, structure, and semantics. So, it is difficult to apply to various services. To solve this issue, we should remove these heterogeneities and convert to context information that is easy to provide context aware services. Also, the existing context aware service mash-up environment require relevant sensor type, criteria of context, programing ability to define the service situation. So, it is difficult to create service for a non-technical user. Therefore, we propose ontology based user-centric service environment to provide context aware IoT services. It provide context awareness and user-desired services using data that acquired via IoT paradigm. The proposed environment consist of the ontology based semantic sensor data processing and the user-centric service environment. It provide convert the object data to the context information and service mash-up process to create user service in easy way.