• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.28-36
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• 1998

In the CDMA mobile communication system with asynchronous mode among base stations, the initial PN code acquisition method using a matched filter can be considered for the rapid PN code synchronization acquisition in the handoff region. In the model of the noncoherent QPSK/DS-SS under the Rayleigh fading channel, the mean acquisttion time of the matched filter is analyzed to have a shortened time in proportion to the length of matched filter to be compared with the serial correlation method. In this paper to improve the HW complexity of the conventional matched device which enables the repeated correlation process, is designed and its function is verified through the FPGAsimulation using Altera MaxPlus Ⅱ.

• The KIPS Transactions:PartB
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• v.14B no.6
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• pp.437-444
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• 2007

The objective of this paper is to accommodate the existing motion-capture-based animation to small memories and low computing powers of mobile embedded systems. To use efficiently memories, we propose a paradigm in which a motion capture database is compressed on a PC and so-compressed motion capture database is decompressed little by little on mobile embedded systems and the decompressed data are eliminated right after used. As a compression method for this paradigm we propose an approach that compresses captured motion rendering parameters using a polynomial function fitting method. To enhance its performance we also propose an optimization method for the degree of the polynomial fitting function. Using so-obtained compression method we demonstrate motion-capture-based animation on commercial mobile embedded systems.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.142-152
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• 2019

There is growing interest in ultra-high-resolution content that gives a more realistic sense of presence than existing broadcast content. However, in order to provide ultra-high-resolution contents in existing broadcast services, there are limitations in view angle and resolution of the image acquisition device. In order to solve this problem, many researches on stitching, which is an image synthesis method using a plurality of input devices, have been conducted. In this paper, we propose method of dynamic object based video stitching using minimal error seam in order to overcome the temporal invariance degradation of moving objects in the stitching process of horizontally oriented videos.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.11a
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• pp.511-514
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• 1998

본 논문은 대용량 통신처리 시스템의 프레임 릴레이망 접속을 통한 인터넷 접속 서비스 기능을 제공하는 프레임 릴레이망 정합 서브 시스템(FNAS : Frame relay Network Access Subsystem)의 설계구조 및 구현사항에 대하여 기술한다. 프레임 릴레이망 정합 서브 시스템은 대용량 통신처리 시스템에 연결되어 전화망(PSTN) 또는 종합 정보통신망(ISDN) 사용자 단말기에 PPP접속기능을 제공하여 프레임 릴레이망에 접속되어 있는 ISP나 CP의 접속을 통한 인터넷 접속 서비스를 제공하거나 정보 제공자(Information Provider)의 DB를 검색하도록 개발하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.14-23
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• 2005

This paper proposes a method for matching two different images, especially satellite images. In the general image matching fields, when an image is compared to other image, they may have different properties on the size, contents, brightness, etc. If there is no noise in each image, in other words, they have identical pixel level and unchanged edges, the image matching method will be simple comparison between two images with pixel by pixel. However, in many applications, most of images to be matched should have much different properties. This paper proposes an efficient method for matching satellite images. This method is to match a raw satellite image with GCP chips. From this we can make a geometrically corrected image. The proposed method is based on wavelet transformation, not required any pre-processing such as histogram equalization, analysis of raw image like the traditional methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.202-207
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• 2016

An auxiliary real-time train communications system among drivers, train-traffic controllers and field workers is necessary to share hazard information (i.e. rockfall detection, track maintenance) in low visibility zones (long tunnels and steep curved track). To develop the appropriate communication system, this paper proposes a new way of power line communication using the rail track (Rail - PLC), which has little noise and distortion of attenuation. Therefore, it is important to measure the impedance of the rail and to apply an impedance matching technique to increase the transmission characteristic of the Rail - PLC. This study would evaluate the reflection and the transmission characteristics of the rail using a network analyzer and an impedance matching transformer. The suitable impedance matching ratio was 1:3.28 from the result of back-to-back testing. The results confirmed that the transformer can improve the performance of the transmission signal in Rail - PLC using an impedance matching technique.

• Electronics and Telecommunications Trends
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• v.15 no.1 s.61
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• pp.1-14
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• 2000

ATM PON 기반의 FTTH 광 정합 망은 향후 가장 효과적이고 경제적인 망이 될 것이므로 FTTC 망을 비용 경제적인 망으로 구현하기 위해서 광 액세스 시스템(ONU)을 최대한 저가격이고 소형이며 저전력을 소모하는 시스템으로 설계할 필요가 있다. 본 연구의 ONU는 FTTC/FTTH 기반의 155Mb/s(OC-3/STM-1) 및 622Mb/s(OC-12/STM-4) 속도의 ATM-PON 광 정합을 위한 광 액세스 시스템이다. 본 고에서는 유니버설 가입자 정합을 통하여 가입자에게 일반 및 공중전화, N-ISDN, 고속 인터넷 접속, 고속 멀티미디어 서비스 등의 다양한 서비스를 제공하기 위한 비용 효과적이고 소형이며 저전력을 소모하는 ONU 설계 및 구현방안을 기술하였다.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.221-223
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• 2004

본 논문에서는 RF 플라즈마를 사용하는 공정장비의 임피던스 정합 특성 개선을 위해 RF Match 제어단의 제어 알고리즘과 하드웨어의 디지털화 방안에 대한 연구를 수행하였다. 개발된 제어단은 최적의 동작성능을 위하여 멀티 프리셋, 이득제어 기능 등 부가기능을 갖도록 설계/제작하였고, 또한 LCD 모듈의 설치를 통하여 RF Match의 실시간 상태 파악이 가능하도록 하였다. 개발된 제어단에 대한 실험결과로부터 RF 전력의 over/under shoot, 플라즈마 플리커 등의 현상이 제거되었고, 정합시간이 크게 단축되었음을 알 수 있었다.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2013.10a
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• pp.698-698
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• 2013

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.98-113
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• 2002

In this paper, we present advanced algorithms to reduce the computations of block matching algorithms for motion estimation in video coding. Advanced multi-level successive elimination algorithms(AMSEA) are based on the Multi-level successive elimination algorithm(MSEA)[1]. The first algorithm is that when we calculate the sum of absolute difference (SAD) between the sum norms of sub-blocks in MSEA, we use the partial distortion elimination technique. By using the first algorithm, we can reduce the computations of MSEA further. In the second algorithm, we calculate SAD adaptively from large value to small value according to the absolute difference values between pixels of blocks. By using the second algorithm, the partial distortion elimination in SAD calculation can occur early. So, the computations of MSEA can be reduced. In the third algorithm, we can estimate the elimination level of MSEA. Accordingly, the computations of the MSEA related to the level lower than the estimated level can be reduced. The fourth algorithm is a very fast block matching algorithm with nearly 100% motion estimation accuracy. Experimental results show that AMSEA are very efficient algorithms for the estimation of motion vectors.