• JOURNAL OF ELECTRICAL WORLD
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• no.4 s.196
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• pp.88-98
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• 1993

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.8B
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• pp.1168-1175
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• 2001

H.263부호기에서 정지영상 부호화를 위한 부가 부호기법인 Annex I는 기존의 JPEG, MPEG-1, -2와는 달리 부호화하고자 하는 현재 블록의 DCT 계수를 기부호화된 블록의 DCT 계수들을 이용하여 예측부호화 (Differential Pulse Coded Modulation; DPCM)를 행하고, 이를 통한 부호화 이득의 향상을 얻고 있다. 본 논문에서는 이런 H.263 Annex I의 예측기법을 공간영역에서의 의미를 수학적으로 유도한다. 이를 통해서 H.263 Annex I의 예측기법의 비효율성을 지적하고, 영상신호의 특성에 맞게 예측방식을 수정한다. 제안된 DCT 계수 예측 방식과 기존의 H.263 Annex I 방식의 이론적인 예측성능을 평가하고, H.263 부호기에 적용하여 제안방식의 효율성을 검증한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1021-1026
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• 2005

In this paper, we present a novel predictive CDMA closed-loop power control (CLPC) method with a multi-step least squares (LS) linear predictor for time-varying fading channels. The proposed method effectively compensates multiple power control group delays and provides significant performance gains over nonpredictive CLPCs as well as conventional predictive CLPCs with one-step linear predictor.

• Journal of the Korea Society of Computer and Information
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• v.19 no.3
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• pp.11-16
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• 2014

In this paper, the two-wheels robot using a predictive controller to maintain the balance of the posture control in real time have been examined. A reaction wheel pendulum control method is adopted to maintain the balance while the bicycle robot is driving. The objective of this research was to design and implement a self-balancing algorithm using the dsPIC30F4013 embedded processor. To calculate the attitude in ARS using 2 axis gyro(roll, pitch) and 3 axis accelerometers (x, y, z). In this study, the disturbance of the posture for the asymmetrical propose to overcome the predictive controller which was a problem in the control of a remote system by introducing the two wheels of the robot controller and the linear prediction of the system controller combines the simulation was performed. Also, the robust characteristic for realizing the goal of designing a loop filter too robust controller is designed so that satisfactory stability of the control system to improve stability of the system to minimize degradation of performance was confirmed.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.85-89
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• 2005

도시발달과 인구증가로 인해 오늘날의 수자원 관리와 계획은 복잡하고 그 중요성은 더욱더 커지고 있으며, 인구와 재산의 집중현상으로 인하여 사소한 수문재해로 인해 막대한 인명과 재산피해를 초래될 수 있다. 이런 이유들로 인해 정확한 수문예측과 이를 통한 적절한 수자원 관리는 그 어느 때보다 중요한 인자로 인식되고 있다. 본 연구에서는 수문예측을 통한 소규모 댐으로의 정확한 월유입량 예측을 실시하여 실측유입량과 비교$\cdot$분석함으로서 수자원관리의 효율성을 향상시키고자 하였다. 수문예측을 위해서 확률론적 예측이 가능한 앙상블 예측기법(Ensemble Prediction Method)을 적용하였으며 과거 1968-1997년까지의 강우데이터와 수정 TANK모형을 이용하여 1998부터 2002년까지의 성주댐의 월유입량 앙상블을 생성하였다. 수문예측뿐만 아니라 유입량예측의 정확성을 향상시키기 위해 수정 TANK모형의 매개변수를 최적화기법 중의 하나인 유전자알고리즘을 이용하여 매개변수를 최적화하였으며 평창강유역과 보청천유역의 실측데이터를 이용하여 모형의 검증을 실시하였다. 또한 강우발생시 과소하게 유출량이 산정되는 것을 보완하기 위해 매개변수를 평수기와 홍수기의 구분하여 모형을 적용하였다. 본 연구에서 제시된 앙상블 예측기법과 최적화된 수정 TANK모형을 이용하여 댐의 수자원을 관리한다면 효율적인 관리가 이루어 질 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.42-46
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• 2009

최근 국지적 집중호우로 인한 인명과 재산피해가 증가하고 있는 실정이며 이러한 피해를 경감하기 위한 하나의 방책으로써 홍수예경보 시스템 구축의 관심이 늘어나고 있다. 그러나, 기존의 홍수예측 시스템은 강우관측치를 모형의 입력 자료로 홍수유출을 계산하는데, 집중호우와 같은 악기상 조건에서는 관측강우자료를 이용한 유출해석 결과를 이용하여 홍수예경보 시스템을 운영할 경우 예방 대응시간의 부족으로 인해 방재 효율성이 떨어지는 한계성을 지니고 있다. 이와 같은 상황에서 정확한 기상예보를 활용한 기상-수자원 연계기법을 개발하여 홍수예경보 시스템에 적용한다면 악기상 감시예측기술의 향상과 더불어 재해의 방지차원에서 매우 유용한 대책이 될 뿐만 아니라 그 활용성을 극대화 시킨다면 수자원분야의 치수기 홍수예측 등에 매우 유용하게 활용될 수 것이다. 이에 본 연구에서는 모형의 입력으로 활용되는 단기 예측강우의 국내 적용성 여부를 검토하기 위해 30km의 공간해상도를 가진 단기지역예보모델인 RDAPS(Regional Data Assimilation and Prediction System) 예측강우 자료에 대하여 수문학적 정확도 분석을 수행하였으며, 예측강우의 정확도 향상을 위한 편차보정 방법을 개발 적용하였다. 또한 산정된 예측강우를 바탕으로 HEC-1 모델과의 연계방안을 제안하고 이를 이용하여 한강수계 주요 댐유역의 예측유입량을 산정, 댐 운영에 대한 적용성을 판단하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1203-1212
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• 2013

In this paper, an intra prediction hardware architecture is proposed to reduce computational complexity of intra prediction in HEVC decoder. The architecture uses shared operation units and common operation units and adopts a fast smoothing decision algorithm and a fast algorithm to generate coefficients of a filter. The shared operation unit shares adders processing common equations to remove the computational redundancy. The unit computes an average value in DC mode for reducing the number of execution cycles in DC mode. In order to reduce operation units, the common operation unit uses one operation unit generating predicted pixels and filtered pixels in all prediction modes. In order to reduce processing time and operators, the decision algorithm uses only bit-comparators and the fast algorithm uses LUT instead of multiplication operators. The proposed architecture using four shared operation units and eight common operation units which can reduce execution cycles of intra prediction. The architecture is synthesized using TSMC 0.13um CMOS technology. The gate count and the maximum operating frequency are 40.5k and 164MHz, respectively. As the result of measuring the performance of the proposed architecture using the extracted data from HM 7.1, the execution cycle of the architecture is about 93.7% less than the previous design.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.1-14
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• 2006

The indirect branch instruction is a most substantial obstacle in utilizing ILP of modem high performance processors. The target address of an indirect branch has the polymorphic characteristic varied dynamically, so it is very difficult to predict the accurate target address. Therefore the performance of a processor with speculative methodology is reduced significantly due to the many execution cycle delays in occurring the misprediction. We proposed the very accurate and novel indirect branch prediction scheme so called data-dependence based prediction. The predictor results in the prediction accuracy of 98.92% using 1K entries, and. 99.95% using 8K But, all of the proposed indirect predictor including our predictor has a large hardware overhead for restoring expected target addresses as well as tags for alleviating an aliasing. Hence, we propose the scheme minimizing the hardware overhead without sacrificing the prediction accuracy. Our experiment results show that the hardware is reduced about 60% without the performance loss, and about 80% sacrificing only the performance loss of 0.1% in aspect of the tag overhead. Also, in aspect of the overhead of storing target addresses, it can save the hardware about 35% without the performance loss, and about 45% sacrificing only the performance loss of 1.11%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.77-84
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• 2017

Generally, a time-varying vibration signal is generated in a rotating machine system, and when there is a failure in the rotating machine, the signal contains noise. In this paper, we propose a system consisting of an adaptive predictor and a binary tree filter bank for analyzing time - varying vibration signals with noise. And the vibration signal analyzed results in this system is used for fault diagnosis of the rotating machine. The adaptive predictor of the proposed system predicts the periodic signal components, and the filter bank system decomposes the difference signal between the input signal and the predicted periodic signal into subband. Since each subband signal includes a noise signal component due to a failure, it is possible to diagnose the failure of the using rotary machine. The validity of the proposed vibration signal analysis method is shown in the simulations, where the periodic components cancelled vibrating signals are decomposed to 32 subband, and the signal characteristics related faults are analyzed.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.85-94
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• 2004

Loop detection systems have been used in real-time signal control system to collect traffic information for estimating queue lengths. The queue length algorithm uses speed as a key variable estimated from occupancy time and average vehicle length. The measurement of average vehicle length is affected from the lengths of feeder cable, but their effects have not yet been evaluated. In this study, the variability of average vehicle length due to the lengths of feeder cable is assessed through a field study, and a practical guidelines is proposed. By applying this result, the operational performance of real-time signal control system could be improved.