• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2703-2708
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• 2014

The conventional bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in arbitrating the bus. The efficiency of bus usage can be determined by the selection of arbitration method. Fixed Priority, Round-Robin, TDMA and Lottery arbitration policies are studied in the conventional arbitration method where the bus transaction cycle, the wait cycle and the priority are primarily considered. In this paper, we propose the arbitration method that considers the wait cycle. Furthermore, we verify the bus transaction cycle and the wait cycle compared with the other arbitration methods through TLM(Transaction Level Model).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1879-1884
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• 2013

The general bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in bus arbitration. In compliance with the selection of arbitration method, The efficiency of bus usage can be determined. Fixed Priority, Round-Robin, TDMA, Lottery arbitration are studied in conventional arbitration method. In this paper, we draw the performance analysis of Fixed Priority, Round Robin, TDMA and Lottery bus arbitration policies due to the data traffic concentration and propose the methods of performance improvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1416-1421
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• 2013

In this paper, the Euclidean distance between the probability density functions (PDFs) for biased errors and a Dirac-delta function located at zero on the error axis is proposed as a new performance criterion for adaptive systems in non-Gaussian noise environments. Also, based on the proposed performance criterion, a supervised adaptive algorithm is derived and applied to adaptive equalization in the shallow-water communication channel distorted by severe multipath fading, impulsive and DC-bias noise. The simulation results compared with the performance of the existing MEDE algorithm show that the proposed algorithm yields over 5 dB of MSE enhancement and the capability of relocating the mean of the error PDF to zero on the error axis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.71-76
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• 2019

Research on indoor location tracking technology using smartphone is actively being carried out. Especially, the movement distance of the smartphone should be accurately measured and the movement route of the user should be displayed on the map. Location tracking technology using sensors mounted on smart phones has been used for a long time, but accuracy is not good enough to measure the moving distance of the user using only the sensor. Therefore, when the user moves the smartphone in a certain posture, it must research and develop an appropriate algorithm to measure the distance accurately. In this paper, we propose a method to reduce moving distance estimation error by removing user 's foot shape by limiting the screen of smartphone in pyramid - based optical flow estimation method.

• Journal of Korea Multimedia Society
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• v.17 no.9
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• pp.1092-1097
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• 2014

It is difficult to perform automatic formation flight of UAV (Unmanned Aerial vehicle) when GPS (Global Positionig System) is out of order or has a system error, since the relative position estimation in the flight group is impossible in that case. In this paper, we design a relative localization system for the automatic formation flight of UAV. For this purpose, we adopt digital beam forming (DBF) to estimate the angle with the central controller of the flight group and Particle Filtering scheme to compensate the estimation error of ToA (time of arrival) method. Computer simulation results present a proper distance between the central controller and a following unit to maintain the automatic formation flight.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.57-64
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• 2016

In this paper, we propose the design of railway safety common data model to provide common transformation method for collecting data from railway facility fields to Real-time railway safety monitoring and control system. This common data model is divided into five abstract sub-models according to the characteristics of data such as 'StateInfoMessage', 'ControlMessage', 'RequestMessage', 'ResponseMessage' and 'ExtendedXXXMessage'. This kind of model structure allows diverse heterogeneous data acquisitions and its common conversion method to DDS (Data Distribution Service) format to share data to the sub-systems of Real-time railway safety monitoring and control system. This paper contains the design of common data model and its DDS Topic expression for DDS communication, and presents two kinds of data transformation case studied for verification of the model design.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.35-38
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• 1998

In this paper we fabricated QMSAs for 850MHz band on the teflon substrate with $\varepsilon_1-2.6, $ $t=1.6mm(\pm0.08)(CGP-500).$ We measured the resonant frequency and the return loss with cutting the gap region between radiation patch and ground plate by a 5mm length step by step. As a result we found that the measured data was not so bad unlike other papers when the gap region was closer to zero, especially under 10mm.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.102-105
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• 2017

본 논문은 기존 국내의 ITS방식인 DSRC의 단점을 보완하기 위해 무선전송 기술인 WAVE를 적용한 WAVE/DSRC 플랫폼 기술 연구에 대해 소개한다. 우선, WAVE/DSRC플랫폼의 소프트웨어 구성도와 그에 따른 WAVE 및 DSRC 태스크 동작 구조 및 컨트롤러에 대해 기술하였다. WAVE/DSRC플랫폼을 적용하여 기존의 ITS방식인 DSRC의 단점을 보완하여 보다 정확하고 신뢰성있는 서비스를 제공 할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.126-128
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• 2017

본 연구는 기존 국내 시장에서 꾸준히 사용되고 있는 코드 분석 장비의 단점으로 지적된 노후화로 인해 최신의 Format에 대응이 힘들며 통신 Interface도 확보되지 못해 PC와의 연동도 극히 제한적이고 생산성 확보에 한계가 있다. 본 리모컨 통합검사기는 리모컨 검사에 필요한 전원 공급, 동작 전류 측정, 코드 분석을 일원화하여 하나의 자동화장치에서 사용할 수 있도록 하는 것이며, 종전의 장비들과는 달리 고해상도 디스플레이와 프로세서를 자체 채용하여 PC없이 Stand-Alone으로 이러한 조작과 검사를 진행할 수 한다. 즉 성능검사에 필요한 전 스텝을 하나의 장비에 일원화하여 검사 LOSS를 최소화하고 신뢰성을 높여 생산성 증대에 기여할 수 있도록 설계되었다.

• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.584-593
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• 2007

BACnet is a standard data communication protocol especially designed for building automation and control networks. BACnet uses the Master-Slave/Token-Passing (MS/TP) protocol as one of its field-level networks. In this study, the performance of the BACnet MS/TP protocol is evaluated using an experimental model. The network performance is investigated and evaluated in terms of token rotation time and round trip time. The experimental results show that the performance of the MS/TP network is heavily influenced by the network traffic load, the assignment of MS/TP node address and the network configuration parameter called $N_{max_info-frames}$. Based on the experimental results, simple practical designing guidelines for BACnet MS/TP network systems are also proposed.