• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.166-168
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• 2002

This paper presents a new numerical algorithm suitable for defining recloser reclaims time and blocking automatic reclosing during permanent faults on overhead lines. It is based on terminal voltage input data processing. The decision if it is safe or not to reclose is determined from the voltage signal of faulted and tripped line phase using Total Harmonic Distortion factor calculated by Discrete Fourier Transform. The algorithm was successfully tested using signals recorded on the real power system. The tests demonstrate the ability of presented algorithm to determine the secondary arc extinction time and to block unsuccessful automatic reclosing of HV lines with permanent fault.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.109-110
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• 2006

The performance of a digital baseband signal processing and data transmission rate depends on the modulation technique. In this paper, We implemented DSP communication system for Underwater acoustic communication using by adaptive BPSK modem technique. In order to implement adaptive modem, we suggested SNR detection block. SNR detection block has the reference SNR value that selects between window filter path and matched filter path. In this paper, suggested system is based on software interface and all Hardware(PLL, modem filter, equalizer etc) is implemented by software, exclusive of DSP, A/D, D/A converter, SDRAM and Flash memory.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.22-25
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• 2003

EOC(Electro Optical Camera)는 한반도 및 전 세계 육지 영역 관측용으로 설계되었다. EOC는 1999년 12월 21일 발사된 다목적 실용위성 1호에 탑재되어 가시광 대역(510 ～730nm)으로 입사하는 복사 정보를 수집해 왔다. 획득된 EOC 영상 자료는 다목적 실용위성 1호의 탑재체 자료전송 시스템(Payload Data Transmission System, PDTS)을 통해 지상으로 전송되며, 수신된 자료에 대한 방사 보정 및 기하 보정 등의 일련의 전처리(Pre-processing) 과정을 거쳐 EOC 표준 영상이 생성된다. EOC 영상에 대한 MTF 보상은 방사 보정 후 수행될 수 있으며, 다목적 실용위성 지상국에서는 사용자의 요구에 따라 EOC 영상에 대한 MTF 보상을 수행하고 그 결과를 제공한다. MTF 보상은 EOC의 점 확산 함수(Point Spread Function)를 이용하여 수행되며, 현재 Wiener 필터를 이용하여 수행되고 있다. 본문에서는 현재 다목적 실용위성 1호 영상처리시스템의 EOC 영상에 대한 MTF 보상을 소개하고, EOC의 점 확산 함수에 기초하여 역 필터(Inverse Filter) 및 의사 역 필터(Pseudo Inverse Filter)를 제작, EOC 영상에 대한 MTF 보상 수행 후 그 결과를 Wiener 필터를 이용한 결과와 비교, 분석한다.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1153-1158
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• 2005

The e-mailing system has brought in an innovative information sharing of data communications and gained ground as an essential tool in doing business which ranges from delivering inside information. exchanging messages between groups and with customers to electronic advertisements. Making the most of the network communication technology, entrepreneurs have established a solid mailing system in their groupware and portal system where they carry out interactive communications through the aerial transmission. This paper analyzes the research results in the field of mailing system of the railroad portal installed by the Korea Railroad Research Institute and illustrates what has been derived in the course the software development at the same time.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.155-163
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• 2001

There are cases that revoke the certification because of disclosure of private key, deprivation of qualification and the expiration of a term of validity based on PKI. So, a user have to confirm the public key whether valid or invalid in the certification. There are many method such as CRL, Delta-CRL, OCSP for the cert-validation of certification. But these method many problems which are overload traffic on network and the CRL server because of processing for cert-validation of certification. In this paper we proposed the realtime cert-validation of certification method which solved problems that are data integrity by different time between transmission and receiving for CRL, and overload traffic on network and the CRL server based on DARC.

• Journal of Biomedical Engineering Research
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• v.12 no.3
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• pp.209-214
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• 1991

Digital fetal monitoring system based on the personal computer combined with the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultra- sound fetal Doppler signal for digital signal conditioning, rectification, low -pass filtering, autocorrealtion function calculation and its peak detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data transmission and on -line analysis of fetal heart rate change including on - line warning system, base -line estmation, acceleration, deceleration and variability. It is one of the most suitable situation to apply the DSP chip for siganl conditioning, digital filtering of ultrasound fetal Dopier signal and fetal heart rate estimation using autocorrelation technique .

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.295-302
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• 2010

Nowadays, due to the development of computers and the information and communication technology, data processing and transmission is made very vastly and fast. The development of the technologies bring many changes and revolutions to the life of ordinary people. Although, e-Business grows continuously, it is in experimental stage in domestic area because of limits of infrastructure. Also, in spite of explosive growth of internet, the research on the internet has not been fully studied yet. The objectives of this study are that how service consumers perceive the flow of e-Business, and that what effect the makes on their satisfaction and re-purchase intention. This means that the research enables a marketing manager to take the meaning of comparative weight among the components of e-Business flow, and to provide very useful information to establish marketing strategies which are close to the consumers.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3150-3152
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• 1999

The efficient representation and encoding of signals with limited resources, e.g., finite storage capacity and restricted transmission bandwidth, is a fundamental problem in technical information processing systems. Typically under realistic circumstances, the encoding and communication of message has to deal with different sources of noise and disturbances. In this paper, I propose a unifying approach to data compression by robust vector quantization, which explicitly deals with channel noise, and random elimination of prototypes. The resulting algorithm is able to limit the detrimental effect of noise in a very general communication scenario. In this paper, based on the robust vector quantization I have an experiment about speech coding.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.175-179
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• 2003

In this paper, we developed a DTV RF (Radio frequency) capture, analysis, and regeneration system adapting digital signal processing and high speed hard disk interfacing techniques and analyzed characteristics of captured RF signal. This system can be used in the various field of DTV transmission because this system can capture the receiving real DTV signals and analyze captured RF signals that contain the complex characteristics of the real-world RF environments and regenerate it in a laboratory without the performance degradation. The system can capture and replay the DTV RF signals in real-time on hard disk. Therefore, there is no limit for the amount of captured data with in the installed storage capacity. We can expect various possible applications for this system such as a tool for the development of the receiver performance analysis, design, and analysis for the DTV coverage areas, etc. This system can also be used as RF signal analyzer.

• Journal of information and communication convergence engineering
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• v.19 no.2
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• pp.67-72
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• 2021

Wireless sensor networks (WSNs) require an enormous number of sensor nodes (SNs) to maintain processing, sensing, and communication capabilities for monitoring targeted sensing regions. SNs are generally operated by batteries and have a significantly restricted energy consumption; therefore, it is necessary to discover optimization techniques to enhance network lifetime by saving energy. The principal focus is on reducing the energy consumption of packet sharing (transmission and receiving) and improving the network lifespan. To achieve this objective, this paper presents a novel improved energy-efficient cluster-based routing protocol (IECRP) that aims to accomplish this by decreasing the energy consumption in data forwarding and receiving using a clustering technique. Doing so, we successfully increase node energy and network lifetime. In order to confirm the improvement of our algorithm, a simulation is done using matlab, in which analysis and simulation results show that the performance of the proposed algorithm is better than that of two well-known recent benchmarks.