• Composites Research
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• v.18 no.6
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• pp.19-25
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• 2005

This paper has performed an experimental study on the hybrid composite carbody of Korean tilting railway vehicle. The hybrid composite carbody has the length of 23m and is comprised of a 40mm-thick aluminium honeycomb core and 2mm-thick woven fabric carbon/epoxy face sheet. In order to evaluate the structural behavior and safety of the hybrid composite carbody, the static load tests such as vertical load, end compressive load, torsional load and 3-point support load tests have been conducted. The test was performed under Japanese Industrial Standard (JIS) 17105 standard. from the tests, the maximum deflection was 12.3mm and the equivalent bending stiffness of the carbody was $0.81\times10^{14}\;kgf{\cdot}mm^2$. The maximum strain of the composite body was below $20\%$ of failure strain of the carbon/epoxy face sheet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3859-3865
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• 2010

Modeling a virtual reader and tags, the emulator system is realized by using a commercial signal generation device to make signal, a data collection equipment, and DSP board. By using a Virtual UHF RFID (860 ~ 960 [MHz]) reader/tags module, a developed RFID reader, protocol of tag, and properties of RF support to provide the way how to verify the suitability to international standards (ISO 18000-6 Type C, EPCglobal C1G2). In this paper, to implement a proposed model reader and tag model, Visual DSP is applied by using DSP board, composing the system's signal generators, signal analyzers and performance verification, the target readers or tags, RFID emulator control computesr and control programs.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.219-227
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• 2011

The superframe structure of IEEE 802.15.4, an international standard for low rate WPAN, is composed of CAP(Contention access period) and CFP(Contention free period). CAP is the contention-based access period, while CFP is contention-free access period for supporting QoS by allocating fixed bandwidth. The standard can support QoS for only a few devices, because the maximum number of GTSs is 7. Furthermore, as the value of BO (Beacon order) or SO (Superframe order) increases, the size of a time slot increases. This makes it difficult to precisely allocate bandwidth for any device, because the bandwidth is allocated by the unit of GTS. The proposed scheme of this paper can reduce the waste of BW in CFP by adaptively reducing the size of a time slot in CFP as the value of BO or SO increases and increase the number of GTSs to 127 by modifying the standard. The performance analysis shows that the proposed scheme can dramatically increase the bandwidth utilization during the CFP when comparing with IEEE 802.15.4.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.997-1003
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• 1999

It is required that synchronization model can describe various multimedia objects flexibly in the view point of time relationship and also respond quality of service requirement about jitter which is time difference between intramedia and skew which is time difference between intermedia. es desirable quality of service requirement. Proposed model applies maximum jitter and skew values which can be allowed, and then it presents high quality of service and real applies maximum jitter and skew values which can be allowed, and then it presents high quality of service and real time characteristics. In this paper we expend Petri-net and propose new synchronization specification model and apply two analysis method of Petri-net to prove oIn this paper we suggest multimedia synchronization model that is based on the Petri-net and servicur model suggested. We compared with other models and showed high QoS.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.1-6
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• 2020

In this study, research on character recognition, which is one of the fields of computer vision, was conducted. Optical character recognition, which is one of the most widely used character recognition techniques, suffers from decreasing recognition rate if the recognition target deviates from a certain standard and format. Hence, this study aimed to address this limitation by applying deep learning techniques to character recognition. In addition, as most character recognition studies have been limited to English or number recognition, the recognition range has been expanded through additional data training on Korean text. As a result, this study derived a deep learning-based character recognition algorithm for Korean text recognition. The algorithm obtained a score of 0.841 on the 1-NED evaluation method, which is a similar result to that of English recognition. Further, based on the analysis of the results, major issues with Korean text recognition and possible future study tasks are introduced.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.437-444
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• 2014

The integrated modular avionics (IMA) system has quite a number of line repalceable moduels (LRMs) in a cabinet. The LRM performs functions like line replaceable units (LRUs) in federated architecture. The video processing module (VPM) acts as a video bus bridge and gateway of ARINC 818 avionics digital video bus (ADVB). The VPM is a LRM in IMA core system. The ARINC 818 video interface and protocol standard was developed for high-bandwidth, low-latency and uncompressed digital video transmission. FPGAs of the VPM include video processing function such as ARINC 818 to DVI, DVI to ARINC 818 convertor, video decoder and overlay. In this paper we explain how to implement VPM's Hardware. Also we show the verification results about VPM functions and IP core performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1613-1620
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• 2011

CSD is IEEE Stan없rd 802.15.4b based Container Security Device which is proposed by the U.S Department of Home Security. It is mounted inside the container to sense opening of the container door. ConTracer is the CSD which is developed in this research whose major features are sensing door opening status as well as history inquiring on internal environment and shock to the container by mounting the temperature/humidity/shock sensors. Moreover, its RFID frequency bandwidth uses 2.4GHz 10 correspond actively to the radio regulations used by different countries. This. paper introduces the development trend of CSD, compares the ConTracer which is developed thru this research and other company's CSD, and introduces CSD System which is designed and established using ConTracer. Finally, the implemented CSD System is verified by applying the demonstration service to container distribution between Korea and Japan.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.1-12
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• 2014

In this paper, we developed an explosion proof type and portable combustible gas leak detector and proposed an algorithm to improve the accuracy for measuring gaseous concentrations. The nation's first we developed an infrared gas leak detector with explosion proof standard(Ex d ib) and improved measuring accuracy by using linearization recursion equation and 2nd Lagrange interpolation polynomial. Together, we advanced their performances and added their easy functions after investigating field demands. To compare our and other company's detectors, we performed measurement tests with eight standard gases made by Korea Gas Safety Corporation. We demonstrated the excellence of our instruments in measuring accuracy other than detecters through experimental results.

• Broadcasting and Media Magazine
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• v.7 no.3
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• pp.12-18
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• 2002

JVT is an international video coding standard that is being developed jointly by VCEG of ITU and MPEG of ISO. The standardization efforts are targeted mainly for a very high compression ratio. JVT is a general video coding technology that may be used in various application fields. JVT began to work seriously on the profiles and levels issues since Geneva meeting, January 2002. Profiles are sub sets of technical tools from the entire tools and levels limit processing power and memory resources of a decoder As of now, three profiles of Baseline, Main and X (not defined name yet) and hierarchically structured levels are defined in JVT FCD. The profiling issue is very important for the JVT s initial objective of Baseline royalty free policy. Royalty free Baseline profiling is currently under practical hurdles and this issue may impact as one of critical factors on the success of JVT standard.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.32-37
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• 2006

ETRI has been developing the Ka-band Antenna subsystem for COMS(Communications, Ocean, and Meteorological Satellite) which will be launched at the end of 2008. The antenna subsystem employs the two parts: East Panel and West panel of spacecraft. ETRI in cooperation with domestic companies are under design phase for the antenna subsystem development. This paper focuses in the Ka-band reflector pointing error analysis to verify the antenna subsystem performance specification, especially EOC gain variation etc. The analysis performed is that induced by reflector surface deformation as a result of thermo elastic distortion. Beam pattern variations are verified by the use TICRA