• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.811-815
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• 2013

In this paper, we proposed and fabricated the single feed microstrip patch antenna with slot for S-DMB(Satellite-Digital Multimedia Broadcasting). In order to improve of frequency properties, patch size, feed length, and slot size were investigated by HFSS simulation program. The manufactured single feed microstrip patch antenna with slot showed that the measured center frequency, the minimum return loss and -10dB bandwidth were 2.64GHz, -34.67dB and 180MHz, respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.347-350
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• 2004

In this paper, PDA(Personal Digital Assistants) terminal is proposed to be used for controlling and managing light facilities efficiently by connecting it to a web-based server system and adding additional functions. The control box of current light facilities may be implemented based on a simple On-Off function. The operational quality of the light facilities will be efficiently improved with some practical advantages such as reduction of required facility, manpower and time in managing the lights and control boxes tv using the popular PDA.

• International Journal of Internet, Broadcasting and Communication
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• v.4 no.2
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• pp.12-16
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• 2012

This paper presents a learning framework that fits the digital age - an e-Friendly PLE. The learning framework is based on the theory of connectivism which asserts that knowledge and the learning of knowledge is distributive and is not located in any given place but rather consists of the network of connections formed from experiences and interactions with a knowing community, thus, the newly empowered learner is thinking and interacting in new ways. The framework's approach to learning is based on conversation and interaction, on sharing, creation and participation, on learning not as a separate activity, but rather as embedded in meaningful activities such as games or workflows. It sees learning as an active, personal inquiry, interpretation, and construction of meaning from prior knowledge and experience with one's actual environment.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.256-258
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• 2011

유무선 통신기술의 발달로 멀티미디어 스트리밍 서비스의 이용이 증가함에 따라 비디오 스트리밍 기법에 관한 연구가 필요하다. 본 논문에서는 끊김 없는 스트리밍 서비스를 제공하기 위하여 네트워크의 상태와 클라이언트의 버퍼 상태를 고려한 전송률 조절 기법을 제안한다. 제안하는 기법은 네트워크의 상태와 클라이언트의 버퍼 상태를 기반으로 전송 비디오의 프레임 수를 우선순위에 따라 차등적으로 폐기함으로써 전송률을 조절한다. 제안 기법을 적용한 스트리밍 시스템을 구현하고 실험을 통해 끊김 없는 비디오의 전송을 확인할 수 있었다.

• 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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.7-14
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• 2009

Lately, NAND flash cards have been used to store massive amounts of multimedia data. However, these nand flash cells itself has a slow operation time and by that, the nand flash cards are not appropriate for high performance massive data transfer. Indeed, most flash card products have a disadvantage in that they require plenty of time to transfer massive amounts of data. Therefore, we propose a new architectural design for the hardware and software of the NAND flash cards by improving their data transfer rate. Our design is based on a multiprocessing which is different from the conventional serial processing method. We simulated our design under the VIP (Virtual IP) environment, and verified our work using FPGA test platforms. As a result, the downloading performances was approximately 160MB/s on VIP and 85.3MB/s on FPGA.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.488-497
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• 2016

Given the potential of mobile applications to create new learning opportunities beyond the prevalent use of digital textbooks and Internet lectures, this study aims to derive types and themes of mobile application content that can be effectively integrated with the school curricula. Twenty primary school teachers participated in this study that examines teachers' perceptions about the advantages and disadvantages of printed and digital textbooks' modality, the advantages and disadvantages of mobile learning, and the themes relevant to develop mobile applications. Findings indicate that it is necessary to develop activity-centered applications for vertical use rather than theme-centered applications for horizontal use. In addition, while most ideas derived from teachers center on multimedia access, there was lack of ideas that leverage the affordances of mobile devices for collaborative interaction and location-awareness. Lastly, to promote the diffusion of mobile learning in school environments, this study suggests the need to overcome teachers' epistemology that perceives mobilization against inquiry activities.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.557-575
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• 2005

Much research in core technologies has been done to make it possible the ubiquitous video services over various kinds of user information terminals anytime anywhere in the way the users want to consume. In this paper, we design plototypesystem architecture for the ubiquitous TV program content consumption based on user preference via various kinds of intelligent information terminals in digital home environment, and present an implementation and testing results for the prototype system. For the system design, we utilize the TV Anytime specification fur the consumption of TV program contents based on user preference in TV programs, and also use the MPEG-21 DIA (Digital Item Adaptation) tools which are the representation schema formats in order to describe the context information for user environments, user terminal characteristics, user characteristics for universal access and consumption of the preferred TV program contents. The proposed ubiquitous content mobility prototype system is designed to make it possible to seamlessly consume contents by a single user or multiple users via various kinds of user terminals for the TV program contents they watch together. The proposed ubiquitous content mobility prototype system in digital home environment consists of a home server, a display TV terminal, and an intelligent information terminal. We use 42 TV programs contents in eight different genres from four different TV channels in order to test our prototype system.

• Journal of Korea Multimedia Society
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• v.22 no.5
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• pp.613-625
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• 2019

The rise of the Internet of Things (IoT) devices have greatly influenced many industries and one of them is healthcare where wearable devices started to track all your daily activities for better health monitoring accuracy and even down to tracking daily food intake in some cases. With the amounts of data that are being tracked and shared between from these devices, questions were raised on how to uphold user's data privacy when data is shared between these IoT devices and third party. With the blockchain platforms started to mature since its inception, the technology can be implemented according to a variety of use case scenarios. In this paper, we present a system architecture based on the healthcare system and IoT network by leveraging on multiple blockchain networks as the medium in between that should enable users to have direct authority on data accessibility of their shared data. We provide proof of concept implementation and highlight the results from our testing to show how the efficiency and scalability of the healthcare system improved without having a significant impact on the performance of the Electronic Medical Record (EMR) that mostly affected by the previous solution since these solutions directly connected to a public blockchain network and which resulted in significant delays and high cost of operation when a large amount of data or complicated functions are involved.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.2104-2117
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• 2014

The propagation of smart devices and the rapid expansion of wireless mobile networks have increased the need for ubiquitous device connectivity and contents access. DLNA is currently being used as the de facto standard for connectivity of consumer devices in the digital home. The guidelines provided by DLNA are intended to facilitate device and contents discovery, management, sharing and distribution. However, consumer experience with DLNA has been rather poor and usability not up to speed. Different problems and issues in limited compatibility have been reported due to manufacturer customizations. Such compatibility issues are often difficult to identify by average consumers who are not savvy in information communications and multimedia technology. In this paper, the design and implementation of a DLNA protocol inspection tool is presented for compatibility analysis among DLNA certified devices. The tool monitors the home network and performs analysis of the underlying protocols used by DLNA. The tool can be used for diagnostics and troubleshooting, enabling the user to identify compatibility issues between devices or problems in the network.