• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.33-42
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• 2011

In this paper we designed and implemented a wireless communication circuit which can control the remote devices integrating RFID and ZigBee. This system unifies transmit part and receive part. And this system recognizes RFID tag data, then the recognized information is controlled by MCU, and transmitted to a remote device through the ZigBee. This is operated on TinyOS. If this system is applied to a entrance security system, it can permit/deny one's entrance as well as control the personal computer or other electronic devices. Our experiment shows the result of the recognized data transmission is very different according to a opened playground and a closed place. The data transmission time is stable in the indoor and the data transmission distance is long in the outdoor. We anticipate that our system be applied the various office oriented domains by connecting to the Wired LAN or the WLAN of IEEE 802.11x category.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.36-42
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• 2009

In the mobile device environment, the context-aware computing has been emerging as a core technology of ubiquitous computing. Compared with a desktop computer, a user interface and resource of mobile device is very limited. Traditional desktop-based user interface has been developed on the basis that a user's activity is static state. In contrast, mobile devices are not able to utilize representative desktop-based interaction mechanisms such as a keyboard and mouse, not only because the activity of a user is dynamic state, but mobile devices have limited resources and small LCD display. In this paper, we introduce an intelligent control system for the mobile device that can utility effectively the limited resource and complement the poor user interface by using an accelerometer being able to sense the physical activity and posture. The proposed system can estimate the user activity, static and dynamic states, and posture watching the PDA at the same time, and the proposed intelligent control system as its application, the backlight ON/OFF on the PDA, is run by the result of the user's behavior.

• The Journal of Information Systems
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• v.23 no.1
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• pp.225-246
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• 2014

With the recent establishment of a ubiquitous environment and the paradigm shift to a smart society, the use of mobile devices, such as smart phones and tablet PCs, has become widespread. Thus, the trend is gradually shifting from using Web-based Instant Messenger to using Mobile-based Instant Messenger. Mobile Instant Messenger refers to a service that allows instant messaging as well as data sending and receiving between individuals with exclusive application programs(mobile Apps), which can be used in portable devices-such as smart phones-with wireless Internet access. Korea's portal sites, telecommunication companies, and even big companies have all rushed into the MIM market to join the competition. The reason so many companies are showing interest in the MIM business is because it is rising as a core platform to substitute portal sites in the mobile society, and MIM is perceived as the best means to attract and secure users. The intention to reuse or use continually was considered an important factor in maintaining a dominant position amidst such fierce competition, and consequently, most research thus far has reflected such thought. However, the frequent or long-term use of a system alone cannot indicate the definite success of the system, nor guarantee its dominant position in the market. On the contrary, MIM dependence, which goes beyond simple repetitive use and indicates a state where users actually or emotionally depend on a specific system, can better explain the user action. However, not much research has been conducted on dependence. The research results showed that lively message, concise message, message responsiveness, and social belonging significantly affected perceived usefulness. Message responsiveness, Link, and social belonging significantly affected flow. Flow significantly affected MIM dependence, and perceived usefulness did not affect MIM dependence. This study has proven that lively message, concise message, message responsiveness, Link, social belonging and perceived usefulness are important antecedents and mediating factors of MIM dependence. Moreover, this study is significant in that it explains the overall process of MIM dependence, and expands on the variety and scope of research that can be applied to MIM-related studies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.529-540
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• 2015

The NGN should support an ubiquitous environment in which users can use multiple devices. Especially, services should be provided to users in a seamless manner across multiple devices which are dynamically found in users' vicinity. Therefore, supporting service continuity is essential in the NGN. Currently the IMS, which is a session control layer for the NGN, deals with session control procedures in detail for service continuity. However, the IMS provides limited methods how users can find target terminals for transferring the session. The target terminals tend to be located near in user's physical location, and could be shared among different users. For providing better service experience in the NGN, The NGN needs to encompass methods to enable for users to use the dynamically-found terminals in users' vicinity seamlessly. In this paper, we introduce a novel registration method based on virtual ISIM by which the target terminals in user's vicinity can register themselves to the IMS, and also we discuss how service continuity is supported.

• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.504-515
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• 2008

Fast transmission speeds and various wired network services have been combined with the convenience and mobility of wireless services. The combination of wired/wireless technologies is spreading rapidly since it enables the creation of new services and provides new features to both users and service providers. In such wired/wireless integrated services, network integration is very important because such systems are integrated by a linkage between heterogeneous networks and they involve an integration of transmission technologies across networks. In this situation, existing security and communication technologies are unsuitable since the network are integrated with heterogeneous networks. The network may also have several security flaws. In existing homogeneous networks, user authentication and key management between heterogeneous networks are required for these new technologies. The establishment of security technologies for heterogeneous devices is a very important task between homogeneous networks. In this paper, we propose a secure and efficient key management system for a heterogeneous network environment. Our system provides secure communications between heterogeneous network devices.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.140-148
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• 2021

In this paper, we intend to improve the availability by integrating Sonobuoy, the most essential detection system used in anti-submarine operations, with LTE communication of smart devices. Anti-submarine capability to respond to the threat of North Korean submarine forces is becoming increasingly important, and continuous research and development is required. This paper aims to enhance the ability of acoustic tactics by using a military-only LTE communication system installed on a ship, smart devices that can be linked to it, and a multi-static sonobuoy controlled by them. The proposed system can increase the visual effect by not only displaying coordinate values by receiving accurate coordinate information of each sonobuoy to a smart device, but also displaying a marker on a map.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.4
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• pp.303-325
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• 2023

Flexible fiber- or yarn-based one-dimensional (1-D) energy storage devices are essential for developing wearable electronics and have thus attracted considerable attention in various fields including ubiquitous healthcare (U-healthcare) systems and textile platforms. 1-D supercapacitors (SCs), in particular, are recognized as one of the most promising candidates to power wearable electronics due to their unique energy storage and high adaptability for the human body. They can be woven into textiles or effectively designed into diverse architectures for practical use in day-to-day life. This review summarizes recent important development and advances in fiber-based supercapacitors, concerning the active materials, fiber configuration, and applications. Active materials intended to enhance energy storage capability including carbon nanomaterials, metal oxides, and conductive polymers, are first discussed. With their loading methods for fiber electrodes, a summary of the four main types of fiber SCs (e.g., coil, supercoil, buckle, and hybrid structures) is then provided, followed by demonstrations of some practical applications including wearability and power supplies. Finally, the current challenges and perspectives in this field are made for future works.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2442-2450
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• 2010

Using sensor devices applied to various objects will be needed wireless network that it is easy to install in them. Tiny devices configured to processor that bas comparatively low computing ability are inappropriate to use devices that are wireless LAN, etc. In result, network devices needed to not only have simple communication protocol, but have Plug and Play function that it works as soon as it connects without installing any device driver. it also will industrially have both low power and low cost because of mobility of it. From IEEE 802.11 standard, WPAN(Wireless Personal Area Network) included in LAN is being developed by WPAN WG(Working Group) on area with low power consumption and low complexity. In addition to, it is standardizing MAC and PRY of the standard that is expected to wirelessly communicate within 10m. WPAN will be used generally in the more near future because of both low power and low cost of Zigbee. In this paper we designed zigbee based user authentication module for a automotive smart-key system.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.735-740
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• 2006

유비쿼터스 가정환경에서 서비스를 제공하기 위한 다양한 장치들은 각기 고유한 인터페이스를 가진다. 사용자는 이 장치들을 제어하기 위해서 각각 다른 인터페이스에 익숙해야 하며, 결국 장치 수만큼의 인터페이스를 다루어야 한다. 이와 같은 불편을 해소하기 위해서는 하나의 입력 장치로 여러 장치들을 조작하는 사용자 인터페이스가 필요하다. 특히 유비쿼터스 가정환경에서는 다양한 장치들의 상태 및 기능 등이 동적으로 변하고, 장치가 설정되는 환경도 일정하지 않기 때문에 사용자 중심의 유비쿼터스 환경을 제공하기 위해서는 다양한 인터페이스를 통합할 필요가 있다. 사용자가 비슷하게 인지하는 이종 장치들의 기능을 통합하여 사용자 인터페이스의 동일한 입력으로 매핑한다면 사용자의 부담을 줄일 수 있을 것이다. 본 논문에서는 유비쿼터스 가정환경의 다양한 장비들과 인터페이스 사이의 입출력 관계를 분석하여 시맨틱 네트워크로 모델링하는 방법을 제안한다. 각 장치의 상태와 기능을 시맨틱 네트워크로 정의하고, 노드나 엣지 사이의 유사도를 평가하여 장치와 사용자 인터페이스 사이를 자동으로 매핑한다. 제안하는 방법을 가정환경 입출력장치에 적용하고, 입출력 매핑을 시뮬레이션하는 환경을 구현하여 유용성을 검증한다.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.299-305
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• 2013

Internet Data is hugely increased for high quality multimedia services and the related techniques is also developed rapidly. This paper is aimed to develop integrated internet data and Digital-Television receiving system with high performance and optimization, which is obtained by one-board integration with load control. It is applicable to various devices like computer, set-top box, home multimedia gateway etc. The performance is proved by evaluation test. It shows that the developed device can be TV tuner and internet AP for more robust multimedia services.