• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.652-663
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• 2002

Recently, many advanced video application services over the mobile wireless networks have required a transcoder which can efficiently reduce the size of compressed video bitstreams. The transcoder can be worked in either the spatial domain or the DCT domain. In this paper, we propose a new fast hybrid-type transcoder which can efficiently reduce the frame size with keeping the visual quality. The proposed scheme consists of two major processes: a transform domain process and a spatial domain process. We also propose a scheme for coding mode selection and motion vector refinement. Experimental results show that our approach can reduce the computational complexity more than any other conventional spatial-domain transcoder with keeping the visual quality.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.4 s.346
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• pp.1-12
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• 2006

In this paper we propose an efficient mobile multimedia communication protocol, mobile terminal software platform and mobile VoIP application for IP-based convergence networks. The Proposed mobile multimedia communication protocol is called as ST-MRSVP (Split tunnel based Mobile Resource reServation Protocol) which integrates split tunnel based Mobile IP and RSVP in order to support hish speed mobility. Since mobile terminal platform supports QoS (Qualify of Service) with keeping seamless mobility, mobile QoS supporting modules are developed and interworked together by means of shared memory mechanism. Testbed is composed of a core-network embedding the proposed protocols and wireless LAN-based access networks. We verify functionality and performance of the proposed techniques by using various mobility test over the testbed. As a result, the proposed architecture can reduce the handover delay time with QoS support under 30% comparing with the standard mechanisms and support voice quality as good as CDMA phone.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.337-341
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• 2008

This paper presents a vibrotactile space mouse which use pin-type vibrotactile display modules and a gyroscope chip. This mouse is a new interface device which is not only an input device as an ordinary space mouse but also a tactile output device. It consists of a space mouse which use gyroscope chip and vibrotactile display modules which have been developed in our own laboratory. Lately, by development of vibrotactile display modules which have small size and consume low power, vibrotactile displays are available in small sized embedded systems such as wireless mouses or mobile devices. Also, development of new sensors like miniature size gyroscope by MEMS technology enables manufacturing of a small space mouse which can be used in the air not in a plane. The vibrotactile space mouse proposed in this paper recognizes motion of a hand using the gyroscope chip and transmits the data to PC through Bluetooth. PC application receives the data and moves pointer. Also, 2 by 3 arrays of pin-type vibrotactile actuators are mounted on the front side of the mouse where fingers of a user's hand contact, and those actuators could be used to represent various information such as gray-scale of an image or Braille patterns for visually impared persons.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.21 no.4
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• pp.149-160
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• 2010

In 1997, Lavagnino defined four stages of technology trends in libraries; but, he left a question about the fifth stage. Based on literature review, the following; Web technology, open source application, library consortia, digitization, wireless, and social media are the main trends in the fifth stage. Analyzing the job advertisements (ads) dating from 2006 to 2010 in systems librarianship, the analysis showed that there are three patterns. The first pattern is that the title of 'system librarian' is no longer specific to managing only the ILS at many libraries. The second pattern - network management skills - is not highly required in the job ads. And the last pattern - especially academic institutions which have archive or special collection departments - was looking for a systems librarian. In addition, Web technology has evolved as the most required skill according to the advertisements, as well as inter-personal skills in a team environment.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1098-1104
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• 2011

Data communications networks at sea can be modelled by multi-layered networks with traditional carriers (RF, satellites), and BWA (wireless LAN, WiBro, LTE), which partially makes it possible the high speed communication services (WWW, VoIP) at sea. In this paper, a novel routing scheme (CPR) is proposed which selects an optimal carrier for each hop in routes based on carrier preferences (CP). The carrier preferences are measured proactively depending on the feasibility of transmission characteristics (transmission rate, cost, and latency time) of the carriers for each application. Performance was compared with that of the OMH-MW (Optimal Medium per Hop based on Max-Win) routing scheme.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.11-19
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• 2015

Due to recent development in mobile devices, the mobile device utilization and many related applications have been increasing. Most of initial applications on mobile devices just showed simple information, but now they processes huge data. However, smart devices have certain limitations in processing massive data. Especially, if the size of data increases, the speed of data processing adversely decreases, so the performance of programs also decreases. If hardware specification of the mobile devices is not enough to handle it, response time will be drastically delayed. To overcome these drawbacks, most of application running on mobile devices communicate with their servers to manage data. XML is a proper language for data communication to send and receive data between servers and mobile devices, because it defines rules of document's format and it is a textual data format and small-sized language. However, mobile devices have limitation such as memory, CPU and wireless network to process huge data and XML also takes a lot of time to communicate with servers and devices and handle data, so it could be overhead in service time. Binary XML is an alternative of performance improvement in data processing, which has XML's benefits and minimizes the XML size by binary coding. However, most of binaryXML which are used on applications don't fit on mobile applications. In this paper, we surveyed many kinds of binaryXML, compared merits and demerits to find a binaryXML for mobile applications. We propose how to use binary XML and implemented an electronic attendance system using binary XML to overcome the limitation of XML and to reduce the load of data communications between servers and devices.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.27-33
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• 2009

With the upcoming u-healthcare era, a way of measurement for vital sign monitoring of cardiac patients is changing as well. In existing measurement of cardiac patients, various wire in ECG measuring equipment has caused much discomfort and inconvenience. In order to decrease the problem, we are developing an efficient measurement of ECG signal using Wireless sensor network. In this paper, we present a way to reduce amount of data by transmitting ECG data collected from radio electrocardiogram sensor based on Zigbee after calculating cardiac rate. And in order to control the error which can be caused by the different ECG signal intensity each individual can has, we also suggest an adaptive pulse measurement model which can measure heart rate with correcting according to different ECG intensity. To verify the suggested model, sensor application was developed and the data was acquired in TinyOS 2.0 environment and the adaptive pulse measurement model was evaluated through the data from the experiments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.3
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• pp.299-309
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• 2006

In recent years, a large natural disasters have occurred due to worldwide abnormal weather and the amount of damage has been increased more resulting from high density population and a large-sized buildings of the urbanized area. In this study. we estimate the flooded area according to rainfall probability intensify and sea level in Woreong dong, Masan occurred flood damages by typhoon Maemi using SWMM, a dynamic rainfall-runoff simulation model in urban area, and then analyze the damage of flood expected area through connecting with GIS database. In result, we can predict accurately expected area of inundation according to the rainfall intensity and sea level rise through dividing the study area into sub-area and estimating a flooded area and height using SWMM. We provide also the shelter information available for urban planning and flood risk estimation by landuse in expected flood area. Further research for hazard management system construction linked with web or wireless communication technology expects to increase its application.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.13-17
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• 2003

By converting movable indirect mass chest X-ray devices for vehicles into digital systems and upgrading it to share information with the hospital's medical image information system, excellencies have been confirmed as a result of installing and running this type of system and are listed hereinafter. 1. Upgrading analog systems, such as indirect mass chest X-ray devices dependent on printed film, to digital systems allows them to be run and managed much more efficiently, contributing to the increase in the stability and the efficiency of the system. 2. Unlike existing images, communication based on DICOM standards allow images to be compatible with the hospital's outer and inner network PACS systems, extending the scope of the radiation departments information system. 3. Assuming chest-exclusive indirect mass chest X-rays, a linked development of CAD (Computer Aided Diagnosis, Detector) becomes possible. 4. By applying wireless Internet, Web-PACS for movable indirect mass chest X-ray devices for vehicles will become possible. Research in these fields must continue and if the superior image quality and convenience of digital systems are confirmed, I believe that the conversion of systems still dependent on analog images to modernized digital systems is a must.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.854-863
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• 2006

As WiBro service providers which provide a wireless multimedia communication service are selected, the commercial service will emerge in the near future. Although the use of efficient multicast technology for multimedia will be essentially required, it would be difficult to design the overall communication network in the early stage by using IP multicast due to technological or commercial issues. Application layer multicast schemes or hybrid multicast schemes also should be considered. In this paper, we propose a hybrid multicast scheme and evaluate its performance against typical IP multicast schemes on modelling of the WiBro network for one of WiBro service providers. We also propose a simulation method for the hybrid multicast on the simulation network for performance evaluation. If the number of mobile nodes reaches a certain point, the performance difference between the hybrid multicast and IP multicast is reduced significantly. We show that hybrid multicast technology can be applied for WiBro service without much performance degradation.