• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.124-130
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• 2008

We present in this paper a method of digital watermarking for video data based on the discrete wavelet transform. In the proposed method, a watermark signal is inserted into the decompressed bitstream while detection is performed using the uncompressed video. This method allows detection if video has been manipulated or its format changed. We embed the watermark in the lowest frequency components of each frame in the un-coded video by using wavelet transform. The watermark can be extracted directly from the decoded video without access to the original video. Experimental results show that the proposed method gives the watermarked video of better quality and is robust against MPEG coding, down sampling and re-encoding to other type of video format such as MPEG4, H.264

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.2
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• pp.38-47
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• 2001

This paper decribes the development of computer-aided design of a very precise progressice die for lead frame of semiconductor chip. The approach to the system is based on knowledgr-based rules. Knowledge of fie이 experts. This system has been written in AutoLISP using AutoCAD ona personal computer and the I-DEAS drafting programming Language on the I-DEAS mater series drafting with on HP9000/715(64) workstation. Data exchange between AutoCAD and I-DEAS master series drafting is accomplished using DXF(drawing exchange format) and IGES(initial graphics exchange specification) files. This system is composed of six main modules, which are input and shape treatment, production feasibility check, strip layout, data conversion, die layout, and post processing modules. Based on Knowledge-based rules, the system considers several factors, such as V-notches, dimple, pad chamfer, spank, cavity punch, camber, coined area, cross bow, material and thickness of product, complexities of blank geometry and punch profiles, specifications of available presses, and the availability of standard parts. As forming processes and the die design system using 2D geometry recognition are integrated with the technology of process planning, die design, and CAE analysis, the standardization of die part for lead frames requiting a high precision process is possible. The die layout drawing generated by the die layout module s displayed in graphic form. The developed system makes it possible to design and manufacture lead frame of a semiconductor more efficiently.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.123-132
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• 1999

This paper describes a research work of developing computer-aided design of lead frame, semiconductor, with blanking operation which is very precise for progressive working. Approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from pasticity theories, experimental results and the empirical knowledge of field experts. This system has been written in AutoLISP on the AutoCAD using a personal computer and in I-DEAS Drafting Programming Language on the I-DEAS Master Series Drafting with Workstation, HP9000/715(64). Transference of data between AutoCAD and I-DEAS Master Series Drafting is accomplished by DXF(drawing exchange format) and IGES(initial graphics exchange specification) methods. This system is composed of five modules, which are input and shape treatment, production feasibility check, strip-layout, data-conversion and die-layout modules. The process planning and Die design system is designed by considering several factors, such as complexities of blank geometry, punch profiles, and the availability of a press equipment and standard parts. This system provides its efficiecy for strip-layout, and die design for lead frame, semiconductor.

• ETRI Journal
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• v.9 no.2
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• pp.96-105
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• 1987

The purpose of this paper is to report the implementation of new frame synchroniazation circuit for D3/PCM.When the D3/PCM signal(1.544Mb/s) is received, the performance of the new frame synchronizer is evaluated by the statistical method according to the parameters BER,es, em. For BER=$10^-2$, es=0 and em=2, the implemented hardware will render the initial search time, the maintenance time and there frame time equals to 2.87ms, 9.9hrs and2.69ms, respectively. Also the proposed frame synchronizer can be easily modified to the practical transmission channels environment and the new 1.544Mb/s signal format.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1655-1658
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• 2004

In this paper, we design and implement remote servo motor control system with real-time micro embedded operating system. The system, where controller and camera image grabber are mounted, handles control commands transmitted from a remote PC web browser. A hard real-time servo motor driver running on the real-time micro embedded OS and then a digital control application which confirms precise sampling time intervals is constructed. Frame grabber images transmitted from camera are saved in a image data format to view on remote PC web browser.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.181-184
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• 2000

In this paper, we described a design of the input buffer system for efficiently dealing with MPEG audio bitstream to demux header and side information, audio data. In order to overcome the limitations of fixed-word manipulation in bitstream demuxing, we proposed a new variable length bit retrieval system with FSM sequencer supporting MPEG audio frame format, and serial buffer demuxing audio stream, FIFO circular buffer including header and side information.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2399-2401
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• 1998

For a medium/small scale DAS, which using the PCS network as the system communication network, we developed the scheme of communication protocol of DAS between master and remote terminal. This paper presents advanced protocol which has basic frame format and data flow for the medium/small scale DAS, and the procedure of the developing sequence.

• ETRI Journal
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• v.9 no.2
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• pp.36-47
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• 1987

We have developed three types of muldexes; they are 140Mbit/s muldex, 565Mbit/s muldex and monitor & control muldex for a 565Mbit/s optical fiber transmission system. The frame format of our own type has been constructed for the M&C muldex, and new direct and parallel reframe techniques have been invented for 140Mbit/s, and 565Mbit/s muldex. Their functions, configurations and perform ance evaluations are described here.

• ETRI Journal
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• v.34 no.3
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• pp.450-453
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• 2012

IEEE 802.11n standards introduced a mixed-mode format frame structure to achieve higher throughput with multiple antennas while providing backward compatibility with legacy systems. Although multi-input multi-output channel estimation was possible only with high-throughput long training fields (HT-LTFs), the proposed scheme utilizes a legacy LTF as well as HT-LTFs in a decision feedback manner to improve the accuracy of the estimates. It was verified through theoretical analysis and simulations that the proposed scheme effectively enhances the mean square error performance.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.58-63
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• 1992

The discrete cosine transform (DCT)-based progressive coding standard proposed by the International Standardization Orgnnization (ISO) Joint Photographic Experts Groups (JPEG) is investigated for medical image compression and the performance of the JPEG is compared to that of the full-frame bit-allocation (FFBA) technique. From the comparison, the JPEG standard appeals superior to the FFBA technique in the following aspects: 1) JPEG achieves higher compression than the FFBA technique with less mean square error. 2) Less Gibb's artifact is observed in the compressed images by the JPEG. 3) Computational time for the JPEG is about one-fourth or the FFBA technique. Other attractive points of the JPEG include: Implementation of the JPEG with VLSIs is commercially available in relative low price and the JPEG compression format can easily be interchangeable with other applications.