• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.834-838
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• 2004

We report on a simple method of fabricating multimode transflective liquid crystal displays (LCDs) using the photoalignment technique. Using a self-masking process of ultraviolet light by the reflector as a photomask as well as a reflective mirror, the periodic multimode is obtained with no additional fabrication processes. Moreover, variations of the cell gap are not required for such trasflective LCDs

• Journal of the Korean Graphic Arts Communication Society
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• v.3 no.1
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• pp.27-41
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• 1985

Following results about Y,M,C mask are obtained by the Indirect-Screen Color Separation Method. We make use of experimental systems which are in use for the student education. In the Camera-back Method of reflection copy, the results are summerized as follows; In the projection Method of transparency copy, the results are summerized as follows; Table moitted.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.220-223
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• 2003

이진 출력 기기에서 연속 계조의 영상을 받아들여 이진값으로 출력하는 이진화 알고리즘 중한 예로 마스킹(masking) 방법이 있으며, 마스크 방식의 단점을 보완하였다. 동일한 마스크의 반복적인 사용으로 인하여 영상의 부분적인 특성을 잘 표현해 주지 못하는 마스크들의 단정을 보완하기 위해서 국부 적응 임계값과 테이블 방식의 적응 파라메타를 제안하였으며, 결과적으로 시각적으로 중요한 경계성분을 강조와 국부 처리시 계조 표현력이 부족한 배경영역도 충분히 표현할 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1692-1695
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• 2007

We describe the image enhancement method of applying two spatial filters with different characteristics adaptively. An adaptive method is introduced so that sharpness enhancement is performed only in regions where the image exhibits significant dynamics, while noise reduction is achieved in smooth regions. Simulation results show that the proposed method improved the image quality.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.369-372
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• 2003

In this paper, we propose impr oved binary tree vector quantization based on spatial sensitivity which is one of the human visual properties. We combine the weights based on spatial masking effect according to changes of three primary colors in blocks of images with the process of splitting nodes using eigenvector in binary tree vector quantization. The test results show that the proposed method generates the quantized images with fine color and performs better than the conventional method in terms of clustering the similar regions. Also the proposed method can get the better result in subjective qualify test and PSNR.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.107-110
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• 2002

Soft masks mean that part or all of the program code for operating system or applications are located in the EEPROM or flash ROM. Since Soft masks allow errors to be corrected and programs to be modified quickly and at minimal cost, they are used primarily during testing and in the field trials. This paper introduces a hardware architecture of IC card for soft masks. We suggest a new down loading scheme for soft-mask ROM connected by an I/O interface. This scheme saves the new IC card development cost and time.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.170-170
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• 2000

This paper deals with on-Line detection of strip movement and real time positioning of brackets of EMD connected with it. Strip movement is detected by 4 line CCD camera and measured position correction value is inputted to motor position controller to control position of brackets.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.859-861
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• 2001

본 논문은 오디오의 masking특성을 적용한 심리음향 모델을 이용하여 오디오의 고음질을 보장하면서 잡음과 압축 등의 공격에 강한 오디오 워터마킹 방법을 제안한다. 제안하는 워터마킹 방법은 심리음향 모델에 의해 생산되는 masking thresholds와 원신호의 power spectral density의 각 주파수별 차이 에너지를 이용하여 시간도메인에서 워터마크를 삽입하는 방법으로 오디오의 품질을 유지할 수 있다. 워터마크로는 자기상관성이 강한 PN-시퀀스를 이용하여 강인한 워터마킹을 구현한다. 그리고 PN-시퀀스와 같은 이진 시퀀스 워터마크의 검출을 위한 유사도 측정식을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6C
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• pp.770-776
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• 2004

The goal of perceptual audio coder is to reduce redundancy and irrelevancy of audio signal based on the concept of masking. Several studies on masking effect reveal that the masking threshold varies as a function of the noise-like or tone-like nature of audio signals. Therefore, tonality of audio signal influences significantly the quality and efficiency of perceptual audio coder In this paper, we propose a new effective algorithm for tonality measure using spectrum energy. Since the proposed algorithm consists of a few transcendental functions and simple operations, it has lower complexity than MPEG psychoacoustic model-II. The proposed algorithm was tested with some audio signals, and DSP implementation showed that the proposed algorithm could be implemented with 3 MIPS. These results illustrate the efficiency of proposed algorithm in both performance and complexity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.421-426
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• 2009

This paper presents vibration analysis of maskless exposure module in Printed Circuit Board (PCB) manufacturing system. In order to complete exposure process in PCB, masking type module has been widely used in electronics industries. However, masking process confronts some limitations of application due to higher production cost for masking as well as lower printing resolution. Therefore, maskless exposure module is started to be in the spotlight for flexible production system to meet the needs of fabrication in variable patterns at low cost. Since maskless exposure process adopts direct patterning to PCB, vibration problems become more critical compared to conventional masking type process. Moreover, movements of exposure engine as well as stage generate vibration sources in the system. Thus, it is imperative to analyze the vibration characteristics for the maskless exposure module to improve the quality and accuracy of PCB. In this study, vibration analysis using the Finite Element Analysis is conducted to identify the critical structural parts deteriorating vibration performance. Also, Experimental investigations are conducted by single/dual encoder measurement process under the operating module speed. Measurement points of vibration are selected by three places, which are base of stage, exposure engine and top of stage, to check the effect of vibration from the exposure engine. Comparisons between analysis results and experimental measurement are conducted to confirm the accuracy of analysis results including the developed FE model. Finally, this studies show feasibility of optimal design using the developed FE analysis model.