• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.735-738
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• 2001

디지털 캠코더에서 이용하는 영상 압축 방식인 DV 부호화방식은 DCT와 가변장 부호화 방식을 이용한다. DV 방식은 하드웨어 복잡도가 낮은 반면 압축된 비트 율이 약 26Mbps로 높은 편이다. 따라서 스튜디오에서 낮은 복잡도로 영상을 부호화 한 후 VOD 시스템에서 이용하기 위하여 MPEG-2로 변환부호화 할 필요가 있다. 이때의 두 압축방식이 DCT를 이용하므로, DCT영역에서 변환부호화 하면 중간과정을 줄일 수 있어서 계산상의 복잡도를 줄일 수 있다. 본 논문에서는 DV방식에서 MPEG-2의 인트라로 변환부호화시, DV방식의 4:1:1 색차포맷을 MPEG-2의 4:2:2 색차 포맷으로 변환할 때 변환영역에 있는 데이터에 미리 계산된 행렬을 곱하여 병렬처리가 가능하게 설계하였다. 또한 MPEG-2 율제어는 중요한 서브 블록의 분산을 완전히 DCT영역에서 계산하여 하드웨어 복잡도를 줄였다. 색차포맷변환부 하드웨어 구현을 위하여 VHDL로 코딩한 후 FPGA-EXPRESS(synopsys), ALTERA MAX-PLUS II를 사용하여 모의실험을 하였다. 각 모듈별로 기능을 검증한 후, FPGA EXPRESS(synopsys)를 사용하여 합성 및 검증을 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.265-268
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• 2002

최근 컴퓨터와 인터넷의 급속한 발전과 더불어 교육 문화는 사용자들로 하여금 새로운 세상을 열어주게 되었다. 21세기 교육이 평생교육사회라는 분야로 집중화되면서 끊임없는 자기 개발로 빠르게 변화하는 지식기반 사회에서 자신의 경쟁력을 키워가고 있다. 원격교육은 바로 이러한 평생교육을 달성 할 수 있는 매우 효과적인 방식으로 언제나 어디서나 누구나 양질의 교육을 받을 수 있는 열린 교육문화로서 본 연구에서는 학습자의 철저한 관리를 통한 학습능력의 향상을 중점으로 별도의 인터넷 접속과정 없이 편리하고 개인성이 보장된 원격 교육 시스템을 구현하는데 목적을 두었다. 본 논문은 MS의 미디어 스트리밍 서비스를 이용한 동영상 강의 시청 및 조절 과정, My_SQL을 이용한 동영상 강의에 대한 서브노트 문서 제공 및 질의 응답이 이루어지는 토론형 시스템 설계, 사용자의 강의 진도 체크와 출결사항 및 수강과목을 편리하게 관리할 수 있도록 설계되어 있다. 또한 시스템의 처리 과정에서 사용자 수강 관리에 연구의 초점을 두었으며 시스템 내에서 실시간으로 이루어지는 학습자 관리를 중점으로 구성되어 있다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.2
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• pp.179-190
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• 2001

In this proposed study, observing and analyzing contrast enhanced abdominal CT images, we segmented the liver automatically. We computed the ratio of each gray value from the estimated gray value range. With the average value of mesh image, we distinguished the liver from the noise parts. We divided the region based on immersion simulation. The threshold value is determined from the mesh image which is generated from each gray value portion of the liver and is used in dividing the liver to the noise region. To get the outline of the liver, we generated template image which represents the lump of the liver, and subtracted it from the binary image. With the results we use the proposed algorithm using 8-connectivity instead of the present opening algorithm, to reduce the processing time. We computed the volume from the segmented organ size and presented a clinical demonstration with the animal experiment

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.4
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• pp.31-43
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• 1999

The main goal of this paper is to design a high performance SVP(Stack based Video Processor) for network applications. The SVP is a comprehensive scheme; 'better' in the sense that it is an optimal selection of previously proposed enhancements of a stack machine and a video processor. This can process effectively object-based video data using a S-RISC(Stack-based Reduced Instruction Set Computer) with a semi -general-purpose architecture having a stack buffer for OOP(Object-Oriented Programming) with many small procedures at running programs. And it includes a vector processor that can improve the MPEG coding speed. The vector processor in the SVP can execute advanced mode motion compensation, motion prediction by half pixel and SA-DCT(Shape Adaptive-Discrete Cosine Transform) of MPEG-4. Absolutors and halfers in the vector processor make this architecture extensive to a encoder. We also designed a VLSI stack-oriented video processor using the proposed architecture of stack-oriented video decoding. It was designed with O.5$\mu\textrm{m}$ 3LM standard-cell technology, and has 110K logic gates and 12 Kbits SRAM internal buffer. The operating frequency is 50MHz. This executes algorithms of video decoding for QCIF 15fps(frame per second), maximum rate of VLBV(Very Low Bitrate Video) in MPEG-4.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.691-702
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• 2004

In this paper, we propose a sequence of method which extrats ROIs(Region of Interests) rapidly from the parcel image of large size. In the proposed method, original image is spilt into the small masks, and the meaningful masks, the ROIs, are extracted by two criterions sequentially The first criterion is difference of pixel value between Inner points, and the second is deviation of it. After processing, some informational ROIs-the areas of bar code, characters, label and the outline of object-are acquired. Using diagonal axis of each ROI and the feature of various 2D bar code, the area of 2D bar code can be extracted from the ROIs. From an experiment using above methods, various ROIs are extracted less than 200msec from large-size parcel image, and 2D bar code region is selected by the accuracy of 100％.

• The Journal of the Korea Contents Association
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• v.8 no.2
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• pp.74-82
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• 2008

This paper investigates chrominance reconstruction methods that reconstruct subsampled chrominance information efficiently using the correlation between luminance and chrominance components in the decompression process of compressed images, and analyzes drawbacks involved in the adaptive-weighted 2-dimensional linear interpolation among the methods, which shows higher efficiency in the view of computational complexity than other methods. To improve the drawback that the spatial frequency distribution is not considered for the decompressed image and to support the application on a low-performance system in behalf of 2-dimensional linear interpolation, this paper proposes the multi-mode reconstruction method which uses three reconstruction methods having different computational complexity from each other according to the degree of edge response of luminance component. The performance evaluation on a development platform for embedded systems showed that the proposed reconstruction method supports the similar level of image quality for decompressed images while reducing the overall computation time for chrominance reconstruction in comparison with the 2-dimensional linear interpolation.

• Journal of Practical Engineering Education
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• v.7 no.1
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• pp.31-37
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• 2015

Terrestrial digital multimedia broadcasting (TDMB) is a method of bringing multimedia images, radio, internet, and television to portable devices through terrestrial digital radio transmissions. TDMB related educations being carried out in colleges are focusing on developing firmware which enables users to choose a wanted service. TDMB transmission frame is made up of synchronization channel (SC), fast information channel (FIC), and main service channel (MSC). Services such as video, audio and date are transmitted in the form of subchannel in the MSC. FIC carries information related to each services and subchannels. This paper presents a TDMB frame analysis simulator for analyzing and displaying FIC data on PC. TDMB frame analysis simulator contains functions such as controlling TDMB receiver through USB, establishing the frequency, bringing FIC to PC, displaying ensemble ID and levels, and displaying informations related to services and subchannels. In addition to that, this simulator has a function of being able to store FIC date and subchannel data. This simulator being developed with C++ is expected to be used to view those data visually so that it helps students to understand the TDMB system better and bring about the educational motivation.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.459-470
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• 2008

DATS which is one of three subsystems of IDACS is responsible to receive Sensor Data, LRIT and HRIT in L-Band and transmit LRIT and HRIT in S-Band from/to COMS satellite. This paper shows detailed test procedures used to verify the performance and functionality of DATS after its implementation was completely finished. As a part of efforts to verify key DATS performance, G/T and EIRP were measured by using solar flux density as radio source. Regarding the verification of DATS functionality, RF loop-back test was conducted to validate if there is no BER degradation excepting MODEM/BB implementation loss occurred in the integrated DATS. Integrated with 13m antenna, DATS successfully restored image from received MTSAT-1R broadcasting data, LRIT and HRIT, of which frequencies are all L-Band. S-Band transmission was also verified through test antenna placed away from 13m antenna by measuring real LRIT and HRIT spectrum in S-Band. From those test results, DATS is determined to be fully ready to communicate with COMS in L-Band and S-Band.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.5
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• pp.70-78
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• 2001

We have developed a novel driving system of 5' true color FED using voltage controlled PWM method which has current control effect. The proposed method has the advantage of voltage controlled pulse width modulation method and current control method. Also, we propose a new circuit model of FED subpixel for circuit simulation of FED driving circuits, considering some parasitic effects, i.e., cross talk, line coupling effect and leakage current to the adjacent cathode lines. Output stage of the data driving circuit is optimized using the proposed circuit model. In video data processing, FED controller uses the parallel processing of R.G.B input data, so duty ratio is maximized and brightness of FED increases. With this results, no noise and high quality performance is achieved in display of 5' true color FED.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.812-821
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• 2009

This paper proposes a novel dynamically reconfigurable switch for various multimedia applications in hybrid NoC systems. Current NoC systems, which adopt hybrid NoC structure with fixed switch and job distribution algorithms, require designers to precisely predict the property of applications to be processed. This paper proposes a reconfigurable switch which minimizes buffer overflow in various multimedia applications running on an NoC system. To verify the performance of the proposed system, we performed experiments on various multimedia applications running on embedded systems, such as MPEG4 and MP3 decoder, GPS positioning system, and OFDM demodulator. Experimental results show that buffer overflow has been decreased by 41.8% and 29.0%, respectively, when compared with NoC systems having sub-clusters with mesh or star topology. Power usage has been increased by 2.3% compared with hybrid NoC systems using fixed switches, and chip area has been increased from -0.6% to 5.7% depending on sub-cluster topology.