• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.5
• /
• pp.311-318
• /
• 2013

Recently, there have been many studies on RFID-based SCM. Yet, studies of synchronizing errors caused by tracking logistics information in supply chain, and activating & monitoring RFID infra is still insufficient. Also, there is no case of developing the intelligent SCM system enabling total monitoring and controlling RFID Infra by applying these technologies. Logistics information synchronization based Smart SCM model is intelligent supply chain service model to monitor the status of the RFID equipments in supply chain and the synchronization of the logistics process in each logistics point through one integrated view, as well as to react instantly by providing the information to help the various decision makings, when the emergency occurs. By adopting global logistics standard, RFID related standard specification, EPCIS standard, and SSI middleware platform, this model provides the domestic standard specification.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.31B no.11
• /
• pp.45-52
• /
• 1994

In recent days low cost, high performance microprocessors have led to construction of medium scale shared memory multiprocessor systems with shared bus. Such multiprocessor systems are heavily influenced by the structures of memory systems and memory systems become more important factor in design space as microprocessors are getting faster. Even though local cache memories are very common for such systems, the latency on access to the shared memory limits throughput and scalability. There have been many researches on the memory structure for multiprocessor systems. In this paper, an asynchronous memory architecture is proposed to utilize the bandwith of system bus effectively as well as to provide flexibility of implementation. The effect of the proposed architecture if shown by simulation. We choose, as our model of the shared bus is HiPi+Bus which is designed by ETRI to meet the requirements of the High-Speed Midrange Computer System. The simulation is done by using Verilog hardware decription language. With this simulation, it is explored that the proposed asynchronous memory architecture keeps the utilization of system bus low enough to provide better throughput and scalibility. The implementation trade-offs are also described in this paper. The asynchronous memory is implemented and tested under the prototype testing environment by using test program. This intensive test has validated the operation of the proposed architecture.

• Journal of KIISE:Computer Systems and Theory
• /
• v.28 no.5
• /
• pp.213-217
• /
• 2001

Excessive memory buffer requirement in continuous media playback is a serious impediment of wide spread usage of on-line multimedia service. Skewed access frequency of available video files provides an opportunity of re-using the date blocks which has been loaded by one session for later usage. We present novel algorithm which minimizes the buffer requirement in multiple sessions of multimedia playbacks. In continuous media playback originated from the disk, a certain amount of memory buffer is required to synchronize asynchronous disk. Read operation and synchronous playback operation. As aggregate playback bandwodth increases, larger amount of buffer needs to be allocated for this synchronization purpose. The focus of this work is to study the asymptotic behavior of the synchronization buffer requirement and to develop an algorithm coping with this excessive buffer requirement under bandwidth congestioon. We argue that in a large scale continuous media server, it may not be necessary to read the blocks for each session directly from the disk. The beauty of our work lies in the fact that it dynamically adapts to disk utilization of the server and finds the optimal way of servicinh the individual sessions while minimizing the overall buffer space requirement. Optimality of the proposed algorithm is shown by proof. The effectiveness and performance of the proposed scheme is examined via simulation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.7A
• /
• pp.678-685
• /
• 2007

We implemented the network synchronization equipment for the optical transmission platform or next generation Packet/TDM(Time Division Multiplexing) data converged switching system and then, presented an impact of wander generation on the NG-SDH optical transmission network.

• Proceedings of the KIPE Conference
• /
• 2013.11a
• /
• pp.65-66
• /
• 2013

본 논문에서는 계통 전압 사고 상황에서 계통 연계형 풍력 발전 시스템이 만족시켜야 할 LVRT(Low Voltage Ride Through) 동작 모의 및 동특성을 분석하였다. 제작한 시뮬레이터는 유도전동기를 이용한 풍력터빈 모델과 영구자석 동기 발전기 그리고 컨버터와 인버터로 구성된 Back to Back Converter를 통해 계통과 연계되는 구조를 가지고 있다. 계통과 연계되는 부분에 슬라이닥스와 변압기 그리고 IGBT를 이용해 계통의 사고를 모의할 수 있는 계통 전압사고 모의 장치를 제작하여 연결하였으며, 이 계통 전압사고 모의 장치는 A, B, C 각 상을 독립적으로 제작해 다양한 계통사고를 모의할 수 있도록 구성하였다. 하드웨어 시뮬레이터와 제안된 계통 전압 사고 모의 장치 분석을 위해 PSCAD/EMTDC 소프트웨어를 이용한 시뮬레이션을 실시하였고 하드웨어 실험을 통해 그 타당성을 검증하였다.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.455-457
• /
• 2008

본 논문에서는 2상 SPMSM을 이용하여 이동로봇의 이동 및 정지를 담당하는 일체형 엑츄에이터를 제작하였다. 이 일체형 엑츄에이터는 동기모터, 브레이크, 드라이브의 조합으로 이루어지며 이동로봇 등에 있어서 동작 및 성능을 좌우하는 구동장치의 핵심부품으로써 이동로봇의 품질 및 성능을 좌우한다고 할 수 있다. 그리하여 이 일체형 엑츄에이터의 핵심부품인 2상 SPMSM과 이를 제어하기 위한 구동장치에 대한 제어시스템을 제안하고 이를 시뮬레이션과 실험을 통해 검증하였다.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.302-304
• /
• 2001

본 논문에서는 다 채널 위상 측정 장치를 전용하드웨어로 구현하기 위한 설계 구조에 대하여 제시하였으며, 연산량이 많은 곱셈기를 시분할에 의해 공유하는 구조를 제시하였다. 또한 페이저 측정을 위한 Sliding-DFT 알고리즘을 순환 구현할 경우의 근사 구현 오차에 관한 정량적인 연구를 수행하였다. 이러한 오차 영향의 해석을 기반으로 하여 곱셈기 공유 구조를 적용한 위상 측정 장치를 설계하고, 설계한 하드웨어의 내부동작을 보여주는 시뮬레이션을 통해 설계의 정확성을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.8
• /
• pp.1848-1853
• /
• 2003

Stuff threshold modulation(STM) technique is analyzed as method for reducing pointer adjustment jitter. The method for jitter reduction is described, and simulation results are presented to illustrate rms jitter performance. The results show that rms jitter value decrease to less than 50％ as compared to a conventional pointer adjustment system.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.169-171
• /
• 2020

지구온난화와 같은 환경적 문제점들로 인해 에너지 저감 및 고효율의 기술개발을 통한 탄소 저감이 주목을 받고 있다. 시대적 관심과 요구에 발맞춰 에너지 저감 효과가 있는 영구자석동기 전동기 등의 신기술을 철도차량에 적용하려는 연구가 활발히 진행되고 있다. PMSM을 철도차량에 적용하기 위해 추진제어장치는 인버터 한 대가 한 대의 전동기를 제어하는 1C1M 방식이어야 하며, 유지보수성과 안정성을 확보하기 위해 전동기와 인버터 사이를 전기적으로 분리해줄 수 있는 차단기가 필요하다. 또한 에너지 저감과 고효율을 달성하기 위해서 추진제어장치는 소형, 경량화 구조로 개발 되어야 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.884-886
• /
• 2012

As the existing radiation Scanning systems use 2-dimensional radiation scanned images, the low accuracy has been pointed out as a problem of it. Two-dimensional radiation images which have different disparity values are acquired from a newly designed stereo image acquisition system which has one additional line sensor to the conventional system. In this paper, we enhanced the scanning efficiency of the stereo X-ray inspection system using the precision control module.