• Journal of Sensor Science and Technology
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• v.23 no.5
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• pp.326-331
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• 2014

In this study, a MEMS microphone that uses $Si_3N_4$ as the vibration membrane was produced for application as an auditory device using a sound visualization technique (sound visualization) for the hearing impaired. Two sheets of 6-inch silicon wafer were each fabricated into a vibration membrane and back plate, after which, wafer bonding was performed. A certain amount of charge was created between the bonded vibration membrane and the back plate electrodes, and a MEMS microphone that functioned through the capacitive method that uses change in such charge was fabricated. In order to evaluate the characteristics of the prepared MEMS microphone, the frequency flatness, frequency response, properties of phase between samples, and directivity according to the direction of sound source were analyzed. The MEMS microphone showed excellent flatness per frequency in the audio frequency (100 Hz-10 kHz) and a high response of at least -42 dB (sound pressure level). Further, a stable differential phase between the samples of within -3 dB was observed between 100 Hz-6 kHz. In particular, excellent omnidirectional properties were demonstrated in the frequency range of 125 Hz-4 kHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2311-2316
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• 2009

Lately, in the automotive market appeared keywords such as convenience, safety in presentation and increase importance of pan of vehicle. Accordingly, the use of many electronic devices was required essentially and communication between electronic devices is being highlighted. Various devices such as controllers, sensors and multimedia device(audio, speakers, video, navigation) in-vehicle connected car network such as CAN, MOST. Modem in-vehicle network managed and operated as purpose of each other. In this Paper, intelligent car navigation considering convenience and safety implement on MOST Network and present system to control CAN Network in vehicle.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.206-208
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• 2013

The fact that the gigantic and luxurious cruise, Titanic, sank into the cold winter sea causing 1,490 casualties in 1912 resulted in discussing safety of life at sea international and Korea has adopted and operated the GMDSS to keep up with those international endeavors to decrease the number of tragic accidents at sea, However, all GMDSS equipment is making a monotonous beep sound when receiving a distress, emergency, safety and even general message so that it might contribute to lowering ship operators' cognitive abilities as well as being dull of safety precautions. So, I'd like to render great services for saving even one person by considering developing an automatic audio alarm device which allows people to respond in a prompt manner as soon as they hear an audion alarm such as a shipwreck.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.165-171
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• 2017

Reading Pen is used mostly in educational purpose, yet its possibility is great as an input device for various IT devices. Reading Pen recognizes tiny dot patterns printed in papers, converts the patterns to corresponding codes, and plays audio contents that match the codes. Recognizing dot patterns and converting to the codes are the main function of Reading Pens, on which we focus and propose a novel algorithm. Such technology is never open to public and this paper is the first open attempt in this area. We test the algorithm and obtain 85% recognition ratio.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.289-291
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• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the uses by the various portable terminals in the mobile environment. Integrated complex reception platform is required to receive multimedia broadcasting services transmitted from various transmission media. In this paper, we present the design and implementation technic for providing the both of terrestrial and satellite DMB services simultaneously using the same hardware platform. The implemented complex receiving terminal to accommodate these DMB services simultaneously need composed of it RF module. it baseband module, it complex control module and the complex de-multiplexer module. The complex control module is designed using uClinux operating system. The complex de-multiplexer, which perform the functions of the address decoder and each DMB stream de-multiplexer, is implemented. with FPGA device. The implemented platform is tested in a real environment and its performance is satisfied with required performance criteria.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.346-350
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• 2009

Digital Multimedia Broadcasting (DMB) is the mobile TV service based on a digital radio transmission system that provides high quality audio/video and other auxiliary data services. As users want to store the DMB content in their device to be consumed later or to be shared among users, a standardized format needs to be specified to guarantee the interoperability for the DMB contents for various devices. DMB AF (Application Format) specification defines a file format for DMB contents and services. It specifies how to combine the variety of DMB contents with associated information for a presentation in a well-defined format that facilitates storage, interchange, management, editing, and presentation of the DMB contents in protected, governed, and interoperable ways. In this paper we present our implementation of DMB AF as part of the development of DMB AF reference software. Our implementation of DMB AF is developed as the reference software for the standard specification that consists of a three applications: packager, media player, metadata browser and collection of supporting libraries used by the applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.590-592
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• 2013

Devices compliant to the Universal Plug and Play (UPnP) Audio Video (A/V) specifications can easily establish multimedia home networks through zero or auto configuration. Despite the existing UPnP certification process many issues concerning interoperability still arise. Capabilities may not be fully implemented or there may be codec issues. Therefore, a means to check and verity interoperability prior to product purchasing or usage is necessary. In this paper, an implementation of a portable control point is proposed to store and manage UPnP device capability information. The portable control point can be used to find UPnP A/V compliant devices that are most compatible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.81-88
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• 2011

Augmented multimedia is a technology to provide additional informations to mobile devices when multimedia contents like video, audio and images are being played. Person Wide Web, PWW, is a scheme for acquiring a link and browsing a corresponding web pages on mobile devices, in which the link is attached any object and space in real world. In this paper we proposed an augmented multimedia E-commerce application system based on PWW scheme which can browse additional informations from video play on public spaces, and implemented on Microsoft Silverlight platform. We showed that the proposed system can support effectively the augmented multimedia E-commerce.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.225-232
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• 2008

When a single source of multimedia contents is distributed to multiple reproduction devices, the audio and video contents require synchronous play for multi-channel stereo sound and lip-synchronization. The multimedia system in vehicle, especially, has researched to move to wireless environments from legacy wired environments. This paper proposes the advanced algorithm for providing synchronized services of real-time multimedia traffic in IEEE 802.11 WLANs [1]. For these, we implement the advanced IEEE 1588 Precision Time Protocol [2] and the environments for simulation. Also, we estimate and analysis performance of the algorithm, then we experiment and analysis after the porting of algorithm in wireless LAN devices (Linksys wrt-350n AP network device) to characterize timing synchronization accuracy.

• Journal of Information Processing Systems
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• v.8 no.3
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• pp.521-538
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• 2012

As the knowledge society matures, not only distant, but also off-line universities are trying to provide learners with on-line educational contents. Particularly, high effectiveness of mobile devices for e-Learning has been demonstrated by the university sector, which uses distant learning that is based on blended learning. In this paper, we analyzed previous m-Learning scenarios and future technology prospects. Based on the proposed m-Learning scenario, we designed cellular phone-based educational contents and service structure, implemented m-Learning system, and analyzed m-Learning service satisfaction. The design principles of the m-Learning service are 1) to provide learners with m-Learning environment with both cellular phones and desktop computers; 2) to serve announcements, discussion boards, Q&A boards, course materials, and exercises on cellular phones and desktop computers; and 3) to serve learning activities like the reviewing of full lectures, discussions, and writing term papers using desktop computers and cellular phones. The m-Learning service was developed on a cellular phone that supports H.264 codex in 3G communication technology. Some of the functions of the m-Learning design principles are implemented in a 3G cellular phone. The contents of lectures are provided in the forms of video, text, audio, and video with text. One-way educational contents are complemented by exercises (quizzes).