• 한국인쇄학회:학술대회논문집
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• 한국인쇄학회 2000년도 추계 학술 발표회 논문집
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• pp.17-28
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• 2000

Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. However, most of the digital proofing devices have lower resolutions than analog proofing systems and differ with actual color presses in the color gamuts. Therefore, proper color compensations are needed for digital color proofing in order to match color between the proofs and the press sheets. In this paper, we used 3-dimensional look-up table(LUT) and tetrahedral interpolation method for the color space conversion between the device independent color space(CIEXYZ or Lab) and the device dependent color space(CMY) to reduce the color differences between the original copy and digital color proofs and the press sheets.

• International Journal of Contents
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• 제6권4호
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• pp.22-29
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• 2010

In flash memory, many previous garbage collection methods only merge blocks statically and do not consider the contents of buffer. These schemes may cause more unnecessary block erase operations and page copy operations. However, since flash memory has the limitation of maximum rate and life cycle to delete each block, an efficient garbage collection method to evenly wear out the flash memory region is needed. This paper proposes a memory compaction scheme based on block-level buffer for flash memory. The proposed scheme not only merges the data blocks and the corresponding log block, but also searches for the block-level buffer to find the corresponding buffer blocks. Consequently, unnecessary potential page copying operations and block erasure operations could be reduced, thereby improving the performance of flash memory and prolonging the lifetime of flash memory.

• 한국인쇄학회지
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• 제14권1호
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• pp.133-146
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• 1996

Eastman Kodak Co. has announced the concept of photo CD System in September, 1990 With Photo CD System technology, Kodak Co. Furnishes a convinent way to view, use and store photographic images. The heart of this system is a format provides progressively higher levels of image quality to meet the demands of NTSC, PAL and HDTV video displays as well as hard copy output. Also, image professionals are instrested in the capability of Photo CD, such as a way to store image at low cost in a high-resolution digital format that can be played back on different computer platforms. Many editors wish to use Photo CD images in the printing and publishing industry. However, Photo CD images were not processed detail enhancement and some others to use in the lithographic offset printing. Therefore, in this paper discribes a method to improve the sharpness of Photo CD images.

• 한국멀티미디어학회논문지
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• 제6권4호
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• pp.583-593
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• 2003

Engineering design applications require the support of long transactions in cooperative environments. The problem of the existing copy/update/merge approaches is that the partial effects of a committed transaction may be not part of the merged version. This paper introduces a new cooperative transaction model, which allows updates to be progressively notified or propagated into other transactions accessing the same object. To support incremental update propagation and notification, we use the term dynamic dependency to define the intertransaction dependency relationships among all the objects checked out from the public database. Consistency in multiple copies of the same object is achieved by a two-phase delta-merge protocol. Our model provides a synchronization of cooperative updates performed in several workspaces without using locking mechanisms.

• 조명전기설비학회논문지
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• 제22권7호
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• pp.28-36
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• 2008

This paper presents a novel prototype of zero current switching pulse frequency modulation (ZCS-PFM )high frequency series resonant inverter using IGBT power module for electromagnetic induction eddy current heated roller in copy and printing machines. The operating principle and unique features of this voltage-fed half bridge inverter with two additional soft commutation inductor snubber are presented including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.

• 한국정보통신학회논문지
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• 제14권9호
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• pp.2049-2056
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• 2010

컴퓨터 소프트웨어의 불법 복제는 정보화사회의 가장 큰 위협 중 하나이다. 이를 해결하기 위한 수많은 불법복제 방지 기술이 등장하였지만 급속히 발전하는 인터넷을 통한 배포를 막기에는 현실적으로 다양한 어려움이 존재한다. 본 논문에서는 인터넷 환경에서 많이 사용되는 Java 프로그램을 대상으로 저작권 보호를 위한 소프트웨어 워터마킹 방안을 제안한다. 제안 방안은 효율적인 구현이 가능하고 실행 파일 저작권 보호를 위해 강건한 소프트웨어 워터마크를 제공한다.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.301-304
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• 2008

This paper presents a lossless inductor snubber-assisted series resonant high frequency inverter using the trench gate IGBTs for the electromagnetic induction eddy current-heated fixing roller in copy and printing machines in a new generation. This soft switching high-frequency inverter can completely achieve zero current soft switching (ZCS) commutation mode transitions and wide power regulation under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally presented for a constant frequency PDM strategy under a ZCS operation, together with its output power regulation characteristics-based on the pulse density modulation. The effectiveness of this soft switching high-frequency inverter is confirmed for the fixing equipment with the induction-heated fixing roller.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권7호
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• pp.302-307
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• 2002

Digital watermarking is the technique, which embeds an invisible signal including signal including owner identification and copy control information into multimedia data such as audio, video, and images for copyright protection. A new MPEG watermark embedding algorithm using complex block effect based on the Human Visual System(HVS) is introduced in this paper. In this algorithm, $8{\times}8$ dark blocks are selected, and the watermark is embedded in the DC component of the discrete cosine transform(DCT) by using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust against MPEG coding, bitrate changes, and various GOP(Group of Picture) changes.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.285-288
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• 2009

The emergency recovery scheme in time of a disaster or accident up to now has been focused on how to build a backup for the public service or communication network in national scale, also, all the mobile operators have done as recovery scheme for the equipment failure in their network was to make a backup copy of billing data or package data, and they have usually studied only on the backup and failure recovery scheme in the circuit-switched network. However, since it has become more probable recently that a disaster or accident could occur in the switching office buildings, a recovery scheme in time of the failure of these entire switching offices became necessary. The purpose of this paper is to propose various recovery schemes, and by having checkups on many issues that could arise while carrying out these schemes, it presents the best solution for each issue. Moreover, it presents the future tasks that need to be studied as well as initial study directions.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.477-479
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• 2015

PUF는 디지털 기기의 복제 방지 기술로서 동일한 회로라도 회로를 구현하는 공정에 따라 선로지연, 게이트 지연 등이 다른 점을 이용하여 복제 여부를 알아내는 기술이다. 본 연구에서는 코팅 PUF 형태의 물리적 보안 디바이스 구현을 위해 해당 디바이스를 다중 유전체 슬래브로 코팅하고, 그 특성을 확인하기 위해 반사 특성을 계산하여 그 유효성을 검증하였다.