• 제어로봇시스템학회논문지
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• 제16권3호
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• pp.245-248
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• 2010

Almost all of control schemes proposed so far have been designed in the continuous-time domain theoretically. Actual systems, however, have been implemented in the discrete-time domain since Micro Control Unit(MCU) and/or microprocessors have been used for the controllers. Thus, the overall system turned to be a sampled-data system, and generally speaking, the ultimate error cannot converge to zero in the actual system even though the proposed control algorithm showed the asymptotic stability in the continuous-time domain. In this paper, therefore, the ultimate error bound of a sampled data system with a short sampling period has been investigated. The ultimate error is shown to be related in the sampling period.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.385-387
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• 2008

When a fault occurs in the distribution system, it is detected by protection system, then protection system is opened and de-energises the feeder where the fault exists. in this paper, the failure rate of protection system will estimate that using a discrete markov approach with failure data of protection system in order to improve the reliability of protection system.

• Communications for Statistical Applications and Methods
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• 제7권2호
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• pp.605-616
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• 2000

Three primary interests frequently raised by mortgage companies are introduced and the corresponding statistical approaches for the default probability in mortgage companies are examined. Statistical models considered in this paper are time series, logistic regression, decision tree, neural network, and discrete time models. Usage of the models is illustrated using an artificially modified data set and the corresponding models are evaluated in appropriate manners.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.816-819
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• 1996

This paper focuses on development of simulation model for SAE J1850 and performance evaluation of a J1850 network. The simulation model has been developed by using discrete event simulation language. SAE J1850 is one of Class B network protocol for general data sharing applications. Through numerous simulation experiments, several important performance factors such as the probability of a successful transmission, average queue delay, and throughput have been evaluated.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.538-541
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• 1999

MPEG-2 AAC(Advanced Audio Coding) is the most advanced coding scheme available for high quality audio coding. This MPEG-2 AAC audio Standard allows for ITU-R ‘indistinguishable’ quality according to at data rates of 320 kb/s for five full-bandwidth channel audio signals. The compression ratio is around a factor of 1.4 better compared to MPEG Layer 3, you get the same quality at 70% of the bitrate. This paper suggest optimization method for MDCT/IMDCT (Modified Discrete Cosine Transform/Inverse Modified Discrete Cosine Transform) in Encoder and Decoder for AAC.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.693-696
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• 1999

This paper presents an analysis of the chaotic behavior in the discrete-time chaotic generator fabricated by CMOS technology. An approximated empirical equation is extracted from the measurement data of a nonlinear function block. Then the bifurcation diagram and Lyapunov exponent and time waveforms and frequency responses of the chaotic generator are calculated and simulated. And results of experiments in the chaotic circuit with the $\pm$2.5V power supply and clock rate of 10KHz are shown, and analysed.

• Communications for Statistical Applications and Methods
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• 제14권3호
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• pp.497-506
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• 2007

Coverage-based NHPP SRGMs have been introduced in order to incorporate the coverage growth behavior into the NHPP SRGMs. The coverage growth function representing the coverage growth behavior during testing is thus an essential factor of the coverage-based NHPP SRGMs. This paper proposes a class of discrete time coverage growth functions and illustrates its application to real data sets.

• ETRI Journal
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• 제19권4호
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• pp.326-343
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• 1997

In this paper, we propose an ATM switch with the rate more than gigabits per second to cope with future broadband service environments. The basic idea is to separate the connection control flow from the data information flow inside the switch. The proposed switch has a dual-plane switch matrix with the synchronous control algorithm. The queuing behaviors of the proposed switch are shown by the discrete-time queuing analysis. Numerical analyses are taken both in the non-blocking crossbar switch and the banyan switch with internal blocking. Results show that a proposed dual-plane $16{\times}16$ switch would have the acceptable performance with maximum throughput of about 95 percent.

• 터널과지하공간
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• 제21권2호
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• pp.117-127
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• 2011

균열암반의 역학적 및 수리적 성질에 암반 초기응력이 미치는 영향을 고찰하였다. 지질 데이터는 스웨덴 원전원료 및 방사성 폐기물 관리회사(SKB)에 의해 수행된 포쉬마크지역의 부지조사로부터 획득되었으며 암반균열망-개별요소법 수치실험(Discrete Fracture Network - Discrete Element Method) 을 통하여 암반의 등가역학적 및 등가수리적 물성을 결정하였다. 수치실험결과 균열 강성의 응력의존성, 균열 방향에 따른 상이한 변형거동, 균열거동에 따른 수리유동 경로의 변화 등의 원인에 의하여 등가역학적 및 등가수리적 물성은 응력의존성이 큰 것을 확인하였다. 본 연구의 결과는 암반 초기응력의 정확한 예측이 특정 부지에서의 경계조건으로서뿐만 아니라 균열암반의 역학적 및 수리적 물성을 이해하는 데도 중요한 역할을 한다는 것을 보여준다.

• 방송공학회논문지
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• 제28권1호
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• pp.100-108
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• 2023

하이브리드 블록 기반 비디오 압축에서 변환 부호화는 공간 영역의 잔차 신호를 주파수 영역으로 변환하여 낮은 주파수 대역에 에너지를 집중시켜 이후 엔트로피 코딩 과정에서 높은 압축률을 달성할 수 있게 한다. 최신 비디오 압축 표준인 VVC(Versatile Video Coding)는 DCT-2(Discrete Cosine Transform type 2), DST-7(Discrete Sine Transform type 7), DCT-8(Discrete Cosine Transform type 8)를 사용하여 주변환을 수행한다. 본 논문에서는 DCT-2, DST-7, DCT-8이 모두 선형 변환임을 고려하여, 선형 변환의 선형성을 이용하여 역변환 시 곱셈 연산량을 줄이는 역변환 방법을 제안한다. 제안하는 역변환 방법은 VVC의 참조 소프트웨어인 VVC Test Model-8.2 (VTM-8.2) 대비 비트율의 증가 없이 부호화 시간과 복호화 시간이 AI(All Intra)에서 평균 26%, 15%, RA(Randon Access)에서 평균 4%, 10% 감소하였다.