• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.12-17
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• 2010

The oil tanker ship over 150GRT must equip oil content meter which satisfy requirements of revised MARPOL 73/78. Online measurement of oil content in complex samples is required to have fast response, continuous measurement, and satisfaction of ${\pm}10ppm$ or ${\pm}10%$ error in this field. The research of this paper is to develop oil content measurement system using analysis of light transmission and scattering among turbidity measurement methods. Light transmission and scattering are analytical methods commonly used in instrumentation for online turbidity measurement of oil in water. Gasoline is experimented as a sample and the oil content approximately ranged from 14ppm to 600ppm. TSK Fuzzy Model may be suitable to associate variously derived spectral signals with specific content of oil having various interfering factors. Proposed Parallel TSK Fuzzy Model is reasonably used to classify oil content in comparison with other models. Those measurement methods would be effectively applied and commercialized to oil content meter that is key components of oil discharge monitoring control equipment.

• 한국통신학회논문지
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• 제34권7A호
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• pp.530-539
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• 2009

Wireless Relaying is a promising solutions to overcome the channel impairments and provides high data rate coverage that appear for beyond 3G mobile communications. In this paper we present end to end BER performance of dual hop wireless communication systems equipped with multiple Decode and Forward relays over Rayleigh fading channel with the best relay selection. We compare the BER performance of the best relay with the BER performance of single relay. We select the best relay based on the end to end channel conditions. We further calculate the outage probability of the best relay. It is shown that the outage probability of the best relay is equivalent to the outage probability when all relays take part in the transmission. We apply Orthogonal Space Time Block coding(OSTBC) at the source terminal. Numerical and simulation results are presented to verify our analysis.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.69-73
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• 2008

본 논문에서는 다중 사용자 시간 도약 펄스 위치 변조(TH-PAM) 초광대역 시스템(UWB System)의 동작을 분석한다. 이상적인 AWGN 채널 환경과 상관 수신기로 TH-PAM과 TH-PPM의 동작을 분석하였다. 두 UWB 시스템의 BER 특성을 나타내는 표준 규칙을 얻기 위하여 전력 스펙트럼 밀도 함수(PSD)를 사용하였으며 시스템 매개 변수들에 실행을 관련시키는 함수를 얻을 수 있었다. 시스템의 Data와 image 전송의 시뮬레이션 결과로 이론적인 분석을 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.205-207
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• 2003

The line impedance is important data that is applied in all analysis fields of electric power system like power flow, fault current, stability and relay calculation etc. Usually, impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding wires, and earth resistance. Therefore, if there is a fault in cable system, these terms will severely be caused much error to calculation of impedance. Therefore, the line impedance were measured for this study in an actual power system of underground cables, and were analyzed by a generalized circuit analysis program EMTP for comparison with the measured value. These analysis result is considered to become foundation of impedance calculation for underground cable.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.50-57
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• 2003

In this paper, the protective relay setting rules of Korean electric power system are studied by analysis of errors to be considered. An accurate operation of protective relays with accurate settings are important in power system reliability. The setting rules are used from the first establishment in 1982 and revision in 1990 Therefore, it needs revise and analysis of the setting rules because of environmental changes such as voltage raise or applied new technology of power system. Two major setting rules are studied. One is the rule for Zones of distance relay for transmission lines. The other is the one of differential current in a differential relay for power transformers. The range of errors in the setting rules accepted in the field experience is studied in simulation of case study. Also some guide lines for the range of errors in the setting rules are presented from the case study using Matlab simulation.

• 한국전자통신학회논문지
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• 제9권12호
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• pp.1365-1372
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• 2014

최근 LTE(Long-Term Evolution) 이동통신시스템이 보급되어 본격적인 서비스가 제공되고 있다. 특히 LTE 시스템은 3G 시스템 등 과거 이동통신시스템 대비 월등한 전송 속도를 보장함으로써 높은 전송 속도를 요구하는 서비스도 이동단말을 통해서 제공될 수 있도록 하고 있다. 향후 IPTV와 같은 멀티미디어 서비스가 LTE 시스템을 통해서 제공되기 위해서는 실제 사용 환경에서 LTE 시스템이 보여주는 전송 속도의 변화에 대한 기본적인 이해가 필요하다. 따라서 본 논문에서는 CQI와 BLER과 같은 무선 품질 지표가 LTE 시스템의 전송 속도에 영향을 미치는 체제에 대해서 살펴보고 실측 결과를 통해서 이를 검증한다.

• 대한전자공학회논문지SP
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• 제48권4호
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• pp.136-141
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• 2011

본 논문에서는 패턴 인식에서 우수한 성능을 보여주는 가우시안 혼합 모델을 이용하여 MCLT 기반 음향 데이터 전송 시스템의 데이터 검출 성능 향상을 위한 방법을 제안하였다. 기존의 MCLT 기반 음향 데이터 전송 시스템에 대해서 분석하고, 이를 기반으로 데이터 검출 알고리즘에서 우수한 성능을 보여주는 특징 벡터를 선택하여 GMM의 입력 벡터로 효과적으로 이용한다. 다양한 음원(rock, pop, classic, jazz)과 마이크-스피커 사이의 거리 (1∼5m)에서 시스템의 성능을 평가한 결과 GMM을 이용한 제안된 방법이 기존의 MCLT 기반 음향 데이터 전송 시스템의 데이터 검출 알고리즘보다 더욱 우수한 데이터 검출 성능을 보였다.

• 한국항공우주학회지
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• 제39권1호
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• pp.63-68
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• 2011

세계 각국은 달 탐사에 대한 연구를 활발하게 진행하고 있으며 우리나라에서도 달 탐사 임무를 수행하기 위한 기초연구가 이루어지고 있다. 성공적인 달 탐사 임무 수행을 위한 통신 시스템의 개발은 달 탐사 프로젝트에 있어서 중요한 부분이다. 본 논문에서는 기저대역 프로세서 개발을 위한 기본 연구로써 달 탐사 통신 링크에 대한 요구조건 분석을 바탕으로 DSP 프로토타입 시스템을 설계하고 심우주 통신을 위한 국제 표준을 고려하여 각 핵심 모듈을 구현한다. DSP 프로토타입의 비트 오류 확률 값을 컴퓨터 시뮬레이션 결과와 비교함으로써 검증한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.152-155
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• 2002

An industrial robot noise has various noise sources such as gears, motors, bearings, and controller fans. Among these, gears are the most dominant source for noise. The gear noise, caused by tooth profile, elastic deformation, machining error and wear, is directly correlated with the transmission error of mating gear. Due to the fact that has several axis and many gears, it is difficult to understand the characteristics of the vibration and noise of robots. In this study, some advanced analysis techniques based on digital signal processing such as power spectrum, time spectral map, RPM map, and etc., were applied for locating the dominant frequency components of the robot noises and identifying their sources. In addition, sound quality analysis was performed in order to evaluate the operator's annoyance. The noise and vibration measurements were carried out at several points during the operation of each axis considering the effect of load and posture of the robot. Eased on the results, proper countermeasures to reduce excessive noise level have been suggested considering the characteristics of sources.

• Current Optics and Photonics
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• 제3권6호
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• pp.531-540
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• 2019

Spectral Amplitude Coding Optical Code Division Multiple Access (SAC OCDMA) is an advanced technique in asynchronous environments. This paper proposes design and implementation of a novel quantum logic gate (QLG) code, with code construction algorithm generated without following any code mapping procedures for SAC system. The proposed code has a unitary matrices property with maximum overlap of one chip for various clients and no overlaps in spectra for the rest of the subscribers. Results indicate that a single algorithm produces the same length increment for codes with weight greater than two and follows the same signal to noise ratio (SNR) and bit error rate (BER) calculations for a higher number of users. This paper further examines the performance of a QLG code based SAC-OCDMA system with NAND and direct detection techniques. BER analysis was carried out for the proposed code and results were compared with existing MDW, RD and GMP codes. We demonstrate that the QLG code based system performs better in terms of cardinality, which is followed by improved BER. Numerical analysis reveals that for error free transmission (10^-9), the suggested code supports approximately 170 users with code weight 4. Our results also conclude that the proposed code provides improvement in the code construction, cross-correlation and minimization of noises.