• 제어로봇시스템학회논문지
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• 제10권3호
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• pp.273-279
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• 2004

This research is concerned with the development of an Internet-based robot system, which is insensitive to the unpredictable internet time delay. For this purpose, a simple mobile robot system that moves in response to the user s direct control on the internet has been developed. The time delay in data transmission is an important problem for the construction of this kind of system. Therefore, the PPS (Position Prediction Simulator) is suggested and implemented to compensate for the time delay problem of the internet. The simulation and experimental results show that the distance error can be reduced using the developed PPS.

• 전자공학회논문지A
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• 제33A권2호
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• pp.50-58
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• 1996

This paper proposes the channel-access protocol suitable to a very high speed photonic WDM network with star configuration, which can provide a high channel utilization and insensitivity to the propagation delay. The proposed protocol employs a control channel and a simple status table to deal with the propagation delay which has been a major limiting factor in the performance of the very high speed optical communication networks. The control channel transmits control information in order to reserve access on data channels, and each node constitutes a status table after the reception of control pckets which holds information about the availbility of destination node and data channel. The proposed protocol is insensitive to the propagation delay time by removing necessity of the retransmission and by allowing parallel transmission of control packet and data packets. It is proved in analysis and discrete event simulation that the proposed protocol is superior in throughput and mean delay, especially at the high load conditions compared to the existing high speed channel-access protocols.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.810-815
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• 2003

This research is concerned with the development of an Internet-based robot system, which is insensitive to the unpredictable Internet time delay. For that purpose, a simple mobile robot system that moves in response to the user' direct control on the Internet has been built. The time delay in data transmission is a big problem for the construction of this kind of system. Therefore, the PPS (Position Prediction Simulator) is suggested and implemented to compensate for the time delay problem of the Internet. The simulation and experimental result show that the distance error can be reduced using the developed PPS.

• ETRI Journal
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• 제39권4호
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• pp.582-591
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• 2017

To address the wire complexity problem in large-scale globally asynchronous, locally synchronous systems, a current-mode ternary encoding scheme was devised for a two-phase asynchronous protocol. However, for data transmission through a very long wire, few studies have been conducted on reducing the long propagation delay in current-mode circuits. Hence, this paper proposes a current steering logic (CSL) that is able to minimize the long delay for the devised current-mode ternary encoding scheme. The CSL creates pulse signals that charge or discharge the output signal in advance for a short period of time, and as a result, helps prevent a slack in the current signals. The encoder and decoder circuits employing the CSL are implemented using $0.25-{\mu}m$ CMOS technology. The results of an HSPICE simulation show that the normal and optimal mode operations of the CSL achieve a delay reduction of 11.8% and 28.1%, respectively, when compared to the original scheme for a 10-mm wire. They also reduce the power-delay product by 9.6% and 22.5%, respectively, at a data rate of 100 Mb/s for the same wire length.

• 대한전자공학회논문지SD
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• 제44권1호
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• pp.36-44
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• 2007

본 논문은 Delay-Insensitive(DI) 지연 모델을 갖는 비동기식 회로에 3치 전압 레벨을 사용한 하이브리드 터너리 데이터 전송 방식을 제안하고, 이를 이용하여 다양한 비동기 프로토콜과의 데이터 송신 및 수신을 위한 래퍼를 설계하였다. 제안된 하이브리드 터너리 데이터 전송 방식은 기존의 2 선식 전송 방식이나 1-of-4 전송 방식에 비해 데이터 전송선을 50% 줄일 수 있으며, 터너리 전송 방식과 비교하였을 때도 50%의 신호 천이 감소 결과를 보였다. 본 논문에서는 $0.18-{\mu}m$ CMOS 공정을 적용하여 래퍼를 설계하고 검증하였다. 하이브리드 터너리 전송 방식이 적용된 래퍼는 2 GHz 이상의 속도로 동작 하였으며 2 선식, 1-of-4, 그리고 터너리 전송 방식에 비해 각각 65%, 43%, 36%의 소비 전력이 줄어든 결과를 보였다. 제안된 전송 방식과 설계된 래퍼 회로는 비동기식 고속 및 저전력 인터페이스로 사용 가능하다.

• 대한전자공학회논문지SD
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• 제44권12호
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• pp.18-24
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• 2007

반도체 공정 기술의 발전으로 인한 개략 배선 지연시간의 증가는 고성능 시스템의 설계를 어렵게 하고 있다. 이 문제를 해결하기 위해 배선에 파이프라인 요소를 삽입하는 방법이 있으나 시스템의 타이밍을 변화시켜 시스템의 기능성을 보장할 수 없다. LIP(Latency Insensitive Protocol)는 임의의 파이프라인 요소의 삽입에 대해 기능성을 보장하지만 처리량이 저하된다. 처리량 저하를 줄이기 위해서는 평면계획 단계에서 처리량을 고려하여 블록을 배치하여야 한다. 이러한 평면계획을 가능하게 하기 위해서 새로운 처리량 계산 방법을 제안하고 평면계획의 비용함수에 적용하였다. 실험 결과, 기존의 휴리스틱 처리량 평가 방법을 적용한 평면계획에 비해 처리량이 평균 16.97% 향상되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.538-541
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• 1998

This paper describes the development of 5.15ns 32kb asynchronous CMOS SRAM using 0.6.mu.m CMOS technology. The proposed high speed embedded SRAM is realized with optimized control circuit and sense amplifier at a power supply of 3V. Using proposed control circuit, the delay time from address input to wordline 'on' is reduced by 33% and mismatch-insensitive sense amplifier can sense a small difference of bit-line voltage fast and stably.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.971-974
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• 2003

본 논문은 DI(delay insensitive) 지연 모델을 적용한 비동기 회로의 데이터 전송시 발생되는 신호 천이의 수를 감소시키기 위한 새로운 데이터 인코딩 기법과 신호 천이 방법을 제시한다. DI 지연 모델을 적용한 비동기 시스템은 배선 지연에 관계없이 동작이 필요한 모듈에만 데이터와 핸드쉐이크를 위한 이벤트 신호를 전송하는 장점을 갖는다. 그러나 신호의 유효성과 동작 완료 검출을 위해 듀얼레일 데이터 인코딩이 필요하며 이는 비동기 회로의 크기를 증가시키고 이로 인해 전력 소비가 증가한다. 전력 소비를 감소시키기 위해 신호 천이의 수를 줄여야 하며, 본 논문에서는 제안한 신호 천이 기법을 적용하여 실험적으로 약 21%의 전력 소비 감소 결과를 얻었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.69-72
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• 2001

Blind equalization of transmission channel is important in communication areas and signal processing applications because it does not need training sequence, nor does it require a priori channel information. Recently, Tong et al. proposed solutions for this problem exploit the diversity induced by antenna array or time oversampling, leading to the second order statistics techniques, fur example, subspace method, prediction error method, and so on. The linear prediction error method is perhaps the most attractive in practice due to the insensitive to blind equalizer length mismatch as well as for its simple adaptive filter implementation. Unfortunately, the previous one-step prediction error method is known to be limited in arbitrary delay. In this paper, we induce the optimal delay, and propose the adaptive blind equalizer with multi-step linear prediction using RLS-type algorithm. Simulation results are presented to demonstrate the proposed algorithm and to compare it with existing algorithms.

• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.29-36
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• 2005

With the rapid growth of the Internet, the Internet-based robot has been realized by connecting off-line robot to the Internet. However, because the Internet is often irregular and unreliable, the varying time delay in data transmission is a significant problem for the construction of the Internet-based robot system. Thus, this paper is concerned with the development of an Internet-based robot system, which is insensitive to the Internet time delay. For this purpose, the PPS (Position Prediction Simulator) is suggested and implemented on the system. The PPS consists of two parts : the robot position prediction part and the projective virtual scene part. In the robot position prediction part, the robot position is predicted for more accurate operation of the mobile robot, based on the time at which the user's command reaches the robot system. The projective virtual scene part shows the 3D visual information of a remote site, which is obtained through image processing and position prediction. For the verification of this proposed PPS, the robot was moved to follow the planned path under the various network traffic conditions. The simulation and experimental results showed that the path error of the robot motion could be reduced using the developed PPS.