• 한국통신학회논문지
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• 제35권1A호
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• pp.16-24
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• 2010

HSUPA(High Speed Uplink Packet Access)는 고속 스케줄링, HARQ, 짧은TTI등을 Node B에서 제공함으로써 HSDPA 에 대응되게 상향링크 쪽의 고속 데이터 전송률을 제공하는 WCDMA의 Rel 6 이동통신 기술이다. WCDMA 시스템의 RNC(Radio Network Controller)와 기지국인 Node B 간의 Iub 구간에서 혼잡을 검출하는 것은 사용자의 통신서비스 품질을 높이기 위해서 매우 중요하다. 이를 위해 TNL 혼잡 검출과 Node B의 링크 버퍼 관찰 방법을 제안하고 이를 통해 얻을 수 있는 패킷 수율에 대해 성능 분석을 하였다. 제안하는 방법을 통해 좁은 Iub 대역폭의 혼잡 검출은 패킷 수율 향상에 도움이 되는 것을 확인할 수 있었다.

• Smart Structures and Systems
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• 제31권5호
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• pp.501-516
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• 2023

Dynamic irregularity and acceleration of bridges subjected to high-speed trains provide crucial information for comprehensive evaluation of the health state of under-track structures. This paper proposes a novel approach for real-time estimation of vertical track dynamic irregularity and bridge acceleration using deep generative adversarial network (GAN) and vibration data from in-service train. The vehicle-body and bogie acceleration responses are correlated with the two target variables by modeling train-bridge interaction (TBI) through least squares generative adversarial network (LSGAN). To realize supervised learning required in the present task, the conventional LSGAN is modified by implementing new loss function and linear activation function. The proposed approach can offer pointwise and accurate estimates of track dynamic irregularity and bridge acceleration, allowing frequent inspection of high-speed railway (HSR) bridges in an economical way. Thanks to its applicability in scenarios of high noise level and critical resonance condition, the proposed approach has a promising prospect in engineering applications.

• KNOM Review
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• 제22권2호
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• pp.39-47
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• 2019

과학기술연구망(KREONET)에서는 기상기후 정보, 고에너지물리, 천문연구, 위성정보데이터, 유전체 연구데이터 등의 빅데이터 중심 첨단 연구 활동을 지원을 수행하고 있다. 기존의 네트워크 보안장비들이 있는 환경에서는 성능 저하가 발생하기 때문에, 고성능 연구전용 네트워크 상에서 성능저하를 방지하고, 고속 연구협업을 위한 방안들이 연구되고 있다. 또한 최근 이슈가 되는 양자컴퓨터의 등장으로 기존 암호체계를 활용한 보안성에 위협이 되고 있다. 본 논문에서는 단대단(End-to-End)의 고속 연구전용 네트워크상에서 양자암호기반의 통신망 구축을 통하여 물리적 보안성을 강화시키는 환경구축과 고성능 전송테스트를 통하여 양자암호기반 통신망을 구성한다. 물리적 암호화 수행시에 망 성능에 미치는 영향을 분석하여, 고성능 연구협업 네트워크 구축을 위한 기초 자료로 활용하고자 한다.

• Journal of Power Electronics
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• 제10권5호
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• pp.505-517
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• 2010

In this paper, an intelligent sliding-mode speed controller for achieving favorable decoupling control and high precision speed tracking performance of permanent-magnet synchronous motor (PMSM) drives is proposed. The intelligent controller consists of a sliding-mode controller (SMC) in the speed feed-back loop in addition to an on-line trained wavelet-neural-network controller (WNNC) connected in parallel with the SMC to construct a robust wavelet-neural-network controller (RWNNC). The RWNNC combines the merits of a SMC with the robust characteristics and a WNNC, which combines artificial neural networks for their online learning ability and wavelet decomposition for its identification ability. Theoretical analyses of both SMC and WNNC speed controllers are developed. The WNN is utilized to predict the uncertain system dynamics to relax the requirement of uncertainty bound in the design of a SMC. A computer simulation is developed to demonstrate the effectiveness of the proposed intelligent sliding mode speed controller. An experimental system is established to verify the effectiveness of the proposed control system. All of the control algorithms are implemented on a TMS320C31 DSP-based control computer. The simulated and experimental results confirm that the proposed RWNNC grants robust performance and precise response regardless of load disturbances and PMSM parameter uncertainties.

• 한국정보통신학회논문지
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• 제5권4호
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• pp.706-715
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• 2001

TCP는 특정 네트워크 기술의 에러 특성이나 대역폭에 상관없이 사용자들에게 종단간의 적절한 성능을 제공한다. 그러므로 TCP의 강점은 인터넷 환경에서 유용하다는 것이다. TCP/IP프로토콜을 사용한 고속 홈 네트워킹에 관련된 어플리케이션이 계속 소개되고 있는 추세이다. 이로 인해 인터넷과 홈 네트워크를 통합한 환경이 요구된다. 본 논문에서는 IEEE1394를 기반으로 하는 고속 홈 네트워크 환경에서의 TCP모델을 적용하고, IEEE1394 기반의 홈 네트워크의 이용효율을 평가해 보았다. 시뮬레이션을 통해 IEEE1394 기반의 흠 네트워크에서의 TCP의 성능 평가에 있어서 다음과 같은 결과를 알 수 있었다. 비등시성의 트랜잭션에서 TCP는 매우 훌륭한 성능을 발휘하였고 한편으로는, 등시성 트랜잭션의 TCP성능은 낮게 나타났다. 등시성과 비등시성의 혼합 트랜잭션에서의 TCP 성능은 작은 크기의TCP 패킷이 사용될 때 보다 나은 처리량을 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.275-278
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• 2000

As the operating frequency of digital modules in network system becomes fast, integrity of signals between modules is regarded as a important factor in high speed system design. To guarantee the signal integrity, many factors that deteriorate quality of signal should be considered. In this paper, we survey many factors which be considered while in designing and imp]ementing the backplane for high speed router and analyze the simulation result and experimental result.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.111-115
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• 2002

The TGV has been developed in a competition with the domestic air transport. But recently, with congestion, do-regulation of air transport and with the increase of number of cities served by the TGV, operators of rail and air transport are looking for a complementarity between the two modes. In this paper, we'll analyse the background and development of high-speed rail-air links in France for a development plan of high speed transportation network in a national level in Korea.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1161-1162
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• 2007

In year 2004 korea runs high speed train KTX for the 5th time in the world. And now the traction power system is quite stabilized. But still a lot of work to develop and abnormal voltage problem is one of them. In this paper, by actual measuring we have collected the abnormal data on the high speed train sub-staion for more than 15 days. The collected data has been evaluated. In the near future collected data will be used planing a countermeasure.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.411-415
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• 2004

In this paper, a double artificial neural network (ANN) approach and the efficient machining database building scheme are presented for the prediction of surface roughness in high-speed machining. In this approach, 4 machining parameters and used for the prediction of cutting force components, and the combinations of 4 parameters and the predicted cutting force components are finally used for the prediction of surface roughness. The experimental results comparing the these results with the predicted values using simple 4 input nodes have been also investigated to verify the effectiveness of the proposed approach.

• 전기학회논문지
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• 제57권9호
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• pp.1652-1659
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• 2008

With the increase of huge amount of data in network systems, ultimate high-speed network has become an essential requirement. In such systems, the encryption and decryption process for security becomes a bottle-neck. For this reason, the need of hardware implementation is strongly emphasized. In this study, a mixed inner and outer round pipelining architecture is introduced to achieve high speed performance of ARIA hardware. Multiplexers are used to control the lengths of rounds for 3 types of keys. Merging of encryption module and key initialization module increases the area efficiency. The proposed hardware architecture is implemented on reconfigurable hardware, Xilinx Virtex2-pro. The hardware architecture in this study shows that the area occupied 6437 slices and 128 BRAMs, and it is translated to throughput of 24.6Gbit/s with a maximum clock frequency of 192.9MHz.