• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.194-197
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• 1988

The unequal bit-error-probability of rate r=b/n binary convolutional code is analyzed. The error protection affored each digit of the b-tuple information word can be different from that afforded other digit. The property of the unequal protection can be applied to transmitting sampled data in PCM system.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.311-314
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• 2002

This paper has been studied a Image watermarking using PN coding operation where frequency band. By using wavelet transformation, This gets high frequency place HH2 where image watermark puts. Also this places that PN code and binary image are operated. And then, this paper has designed image watermarking index process and extract process, watermarked image which are to add noise is able to extract watermark.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.197-200
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• 2015

Several contact binary systems in four stellar clusters or their fields are reported here; NGC7789-V12, EP Cep and ES Cep in NGC188, NGC104-V95 and V710 Mon. Their multiple light curves were analyzed by the 2010 version of the W-D code, and their physical parameters were obtained.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.34-34
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• 2004

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1047-1050
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• 2004

버퍼 오버플로우 공격의 방어는 그 심각한 위험성 때문에 많은 연구가 되고 있지만 방어에 의한 오버헤드의 발생으로 인해 실제 적용되기 어려운 면이 있다. 본 논문은 이진 코드를 재작성 하여 스택의 리턴 주소 사본을 지역변수 아래 부분에 두고 함수 반환시 비교 검사를 하는 것으로써, 소스코드가 없는 경우에도 버퍼 오버플로우 공격을 막는 동시에 오버헤드를 줄일 수 있는 방법을 제안하였다.

• Journal of IKEEE
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• v.13 no.1
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• pp.65-70
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• 2009

We propose an ultrashort pulse optical code-division multiple-access (O-CDMA) scheme based on a pseudorandom binary M-sequence spectral phase encoding and decoding of coherent mode-locked laser pulses and perform a numerical simulation to analyze its feasibility. We demonstrate the ability to properly decode any of the multiple (eight) 10 Gbit/s users by the matched code selection of the spectral phase decoder. The peak power signal to noise ratio of properly and improperly decoded $8{\times}10 Gb/s$ signals could be greater than 15 for 127 M-sequence coding.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.961-967
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• 2014

Raptor codes are a class of rateless codes originally designed for binary erasure channels. This paper presents a compact set of mathematical expressions for iterative soft decoding of raptor codes. In addition, an early termination scheme is employed, and it is embedded in a single algorithm with the formula. In the proposed algorithm, the performance is enhanced by adopting iterative decoding, both in each inner and outer code and in the concatenated code itself between the inner and outer codes. At the same time, the complexity is reduced by applying an efficient early termination scheme. Simulation results show that our proposed method can achieve better performance with reduced decoding complexity compared to the conventional schemes.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.215-219
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• 2014

C programming language has undefined behaviors, which cause unintended execution of a program. When a programmer adds sanity checks without caring about undefined behaviors, compilers may misunderstand and invalidate the sanity checks. Thus, we propose an automated system to detect invalidated sanity checks by marking sanity checks in source code and checking the marks in binary code.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2632-2635
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• 2003

This paper designs a software signal generator for the new GPS L2 civil signal. The CM/CL code and the message structure of L2CS described in GPS ICD PPIRN-200C-007 are used in designing the signal generator. The output of the GPS signal generator is designed as the sampled IF data with the sampling frequency 5.7MHz and stored in the binary data format. By analyzing both the spectrum characteristics of the output signal and the correlation properties of the CM/CL code, the validation of the designed GPS signal generator is shown. It should be mentioned that the modeling of the GPS satellite constellation and the error sources remains for implementing the software space segment of GPS.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.33-38
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• 1996

A multi-media binary DS/CDMA system with variable processing gain and coherent correlation receivers are considered under additive white Gaussian noise channels. Two types of information sources with different rates and transmitting powers are assumed to be transmitted simultaneously in the same channel. Average signal-to-noise ratios at the correlation receiver outputs for each type of information sources are analytically derived as functions of discrete partial cross-correlations between spreading code sequences. The analysis is expected to provide analytical tools for use in preliminary system design and spreading code selection.