• 한국정보통신학회논문지
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• 제5권6호
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• pp.1184-1189
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• 2001

본 논문에서는 참고문헌 11에서 제안한 세미랜덤 인터리버를 사용한 터보코드의 성능을 분석하였다. 그리고 현재 이동통신시스템에서 사용하고 있는 길쌈부호의 비터비 복호 알고리즘과 구속장이 일정할 때 두 부호의 복호 성능을 비교 분석하였다. 그 결과 길쌈부호와 터보코드가 BER = $10^{-4}$ , 구속 장이 5일 때 세미랜덤 인터리버를 사용한 터보코드가 길쌈부호보다 약 $E_{b/}$ $N_{o}$ =4.7[㏈] 우수함을 입증하였다.다.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.294-298
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• 2009

In this paper we proposed a new Bragg grating waveguide in order to improve reflectivity and to achieve compactness. Bragg gratings with various thicknesses were engraved in the middle of the core layer with a length of 3 mm. For the sake of cost-effectiveness, the $3^{rd}$ order Bragg grating waveguides were fabricated via conventional photolithography. The maximum reflectivities for the fixed width waveguide of $6{\mu}m$ with the 0.1 and $0.3{\mu}m$-thick Bragg gratings were, -13.14 and -6.25 dB, respectively, and the Bragg wavelengths were 1562.28, 1564.10 nm, respectively. A slight increase in the Bragg grating thickness can result in a remarkable reduction in the length of the Bragg grating waveguide with a fixed reflectivity.

• Ocean Systems Engineering
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• 제1권1호
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• pp.59-72
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• 2011

The objective of this work is to investigate the possibility of using the longitudinal strain on the surface of a pipe to determine the inception of dangerous free spanning. The long term objective is to develop an online monitoring technique to detect the development of dangerous free spanning in subsea pipelines. This work involves experimental study as well as finite element modeling. In the experiments, the strains at four points on a cross section of a pipeline inside the free span zone are measured. Pipes with different boundary conditions and different diameter to length ratios were tested. The pipe is treated as a simple beam with fixed-fixed or simply supported boundary conditions. The variation of the strains as a function of the diameter to length ratio gives a pointer to the inception of dangerous free spanning. The finite element results agree qualitatively with the experiments. The quantitative discrepancy is a result of the difficulty to replicate the exact boundary conditions that is used by the finite element program.

• 전자공학회논문지A
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• 제31A권6호
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• pp.9-17
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• 1994

ATM (Asynchronous Transfer Mode) has a fixed-length packet transport scheme. It is one of the promising proposals in B-ISDN.Since the packet length is fixed, it can be potentially to perform the various service to users. In this paper, a queueing model for an ATM multip`exer loaded by CBR and ON/OFF input sources is considered, and the two-queue system which each type of input sources has a queue with a finite capacity is analyzed. The cell loss probabilities for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. As a result, the cell loss probability of ON/OFF sources for the queue size is rapidly decreased when the multiplexed number and burstiness are increased. Since cells of the CBR source have lower priority than cells of the ON/OFF source, cell loss probabilities of CBR sources are accordingly high independently of CBR cell arrival rate when the number of CBR sources is large.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.547-549
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• 2014

RFID 시스템의 태그 식별 성능은 동시에 응답하는 태그들로 인한 태그 충돌 확률과 밀접한 관계가 있다. PS 알고리즘은 리더의 송신 전력을 점진적으로 증가시키면서 리더의 식별 영역 내에 있는 태그들을 그룹화하여 식별하는 기법이다. 이 기법에서는 매 스캔 과정을 수행할 때마다 고정된 크기의 프레임을 사용한다. 이로 인하여 PS 알고리즘의 성능은 태그의 수, 프레임 크기, 및 전력 증가 값에 따라 다양하게 나타나는 문제점이 있을 것으로 예상된다. 따라서 본 논문에서는 프레임 크기와 전력 증가 값에 따른 PS 알고리즘의 성능을 분석한다.

• 수산해양교육연구
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• 제23권2호
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• pp.210-220
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• 2011

The Keyongin Inland waterway will connect with Han-River and the Northen part of the Incheon-seaway and this way will be opened at the early of October this year. In this regard, the Incheon container terminal is under constructing for 1,000 TEU & 550 TEU container vessels at the place of leftside of the Seohae lockgate. However the terminal length is not still fixed due to at a great expenses of construction and dosposal matter of the dredged soil. So this paper will suggest the optimum berth length by using the full mission shiphandling simulator for berthing and unberthing shipmaneuvering. And also evaluates the design standard of harbor construction rules and analysis optimum berth length against ship's length for safe shiphandling at terminals in accordance with the customary practices of the major ports in Korea.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.285-288
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• 2002

In this paper, a new structure of 1024-bit high-speed RSA cryptosystem has been proposed and implemented in hardware to increase the operation speed and enhance the variable-length operation in the plain text. The proposed algorithm applied a radix-4 Booth algorithm and CSA(Carry Save Adder) to the Montgomery algorithm for modular multiplication As the results from implementation, the clock period was approached to one delay of a full adder and the operation speed was 150MHz. The total amount of hardware was about 195k gates. The cryptosystem operates as the effective length of the inputted modulus number, which makes variable length encryption rather than the fixed-length one. Therefore, a high-speed variable-length RSA cryptosystem could be implemented.

• 물과 미래
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• 제29권2호
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• pp.191-198
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• 1996

본 논문에서는 icing의 모양을 대표적으로 나타낼 수 있는 적절한 특성길이의 선정에 대해 서술하였다. 실험 자료를 분석한 결과, 어떤 하나의 길이 단위로 특성길이를 정의하기는 곤란하였다. 특히, glaze icing 의 경우에는 그 형상이 매우 복잡하여 특성길이를 결정하기가 매우 어려웠다. 그러나, 바람의 방향에 수직한 단면의 길이로 정의되는 icing 길이가 icing으로 인한는 하중을 나타내기에는 실린더 혹은 전선의 지름 보다는 더 적절한 특성길이라 판단된다.

• 대한기계학회논문집B
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• 제34권3호
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• pp.229-235
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• 2010

원관 내부반경이 변하는 사각형상 환형 훤의 최적 값들이 변수 분리법에 의하여 제시된다. 최적의 열손실이 존재할 수 있는 주위 대류특성계수의 범위가 나열된다. 최적 열손실, 그와 관련된 최적의 훤 유용성, 훤 길이 그리고 훤 높이가 원관 내부반경, 내부유체 대류특성계수, 훤 체적, 그리고 주위 대류특성계수의 함수로 표현된다. 결과 중 하나는 훤 체적과 훤 바닥반경이 고정되었을 때 최적 열손실, 유용성 그리고 훤 길이는 원관 내부반경의 증가에 따라 선형적으로 증가함을 보여준다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.163-166
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• 1997

In order to shorten head-way time on existing railway lines without any change of signal block length between stations, it is a realistic optional way to change the control method of train signal, i.e. to modernize the cab signal using transponder. A new signalling system of operation pattern control technique is suggested as new model to increase the railway traffic efficiency. Through the computer simulation of this model, the train head-way time by the fixed signalling system and the new pattern control system is analyzed.