• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.381-382
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• 2010

The management system of next digital map will contributes the systematic management for large dataset and huge data. To develop the management system, the requirements are analyzed and applied through the analysis of characteristics of middleware management, editor and component.

• 한국IT서비스학회지
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• 제3권2호
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• pp.85-98
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• 2004

As the e-Commerce based on the XML technology is getting bigger, user authentication, integrity, non-repudiation and confidentiality has become important for security. Since the XML technology is widely used for exchanging information among the Internet e-business systems, the security of XML documents is essentially required and XML digital signature should be supported. To support the digital signature of XML documents, W3C proposed the XML-Signature specification as an international standard that describes five transform algorithms. In this paper, we design and implement a XML/PKI based digital tax invoice system. Our system supports the five transforming algorithms defined in the XML-Signature specification and exchanges digital tax invoices among enterprises securely. We design and implement the flexible and efficient system consists of reusable components using CBD(Component Based Development).

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.157-166
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• 2016

In this paper, a new sag and peak voltage detector is proposed for a single-phase inverter using delta square operation. The conventional sag detector is from a single-phase digital phase-locked loop (DPLL) that is based on d-q transformations using an all-pass filter (APF). The d-q transformation is typically used in the three-phase coordinate system. The APF generates a virtual q-axis voltage component with a 90° phase delay, but this virtual phase cannot reflect a sudden change in the grid voltage at the instant the voltage sag occurs. As a result, the peak value is drastically distorted, and it settles down slowly. A modified APF generates the virtual q-axis voltage component from the difference between the current and the previous values of the d-axis voltage component in the stationary reference frame. However, the modified APF cannot detect the voltage sag and peak value when the sag occurs around the zero crossing points such as 0° and 180°, because the difference voltage is not sufficient to detect the voltage sag. The proposed algorithm detects the sag voltage through all regions including the zero crossing voltage. Moreover, the exact voltage drop can be acquired by calculating the q-axis component that is proportional to the d-axis component. To verify the feasibility of the proposed system, the conventional and proposed methods are compared using simulations and experimental results.

• 한국정보통신학회논문지
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• 제20권4호
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• pp.826-832
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• 2016

본 논문에서는 고가의 디지털 설진 장비와 특별한 장치 없이 누구나 손쉽게 사용할 수 있는 디지털 설진 시스템의 첫 단계로 미각 영역별 균열 유무를 판별하는 시스템을 제안한다. 훈련 DB는 한방 병원에서 수집한 사진 261장을 바탕으로 Haar-like feature, Adaboost 학습을 하였다. 학습된 결과를 통하여 입력영상으로부터 혀 후보영역을 검출하고, 검출된 혀 후보영역으로부터 혀 영역만을 분리하기 위하여 261장의 훈련 DB의 HSV 컬러모델의 Hue 성분 평균 값을 산출하였다. 검출된 혀 윤곽으로부터 Connected Component Labeling을 통하여 혀 영역을 분리 하였다. 분리된 혀 영역의 상대적 너비와 높이를 이용하여 미각 영역별 로 분할하였다. 분할된 미각 영역별 영상은 Gray영상으로 변환하고, 각각의 영역별 평균 밝기를 산출하여 이진화하였다. 이진화 영상에 Connected Component Labeling을 통하여 균열 유무를 판별하였다.

• 디지털콘텐츠학회 논문지
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• 제8권3호
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• pp.329-339
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• 2007

본 논문은 연속적으로 입력되는 동영상에서 시공간 정보를 이용하여 다양한 조명환경에서도 실시간 적용이 가능한 얼굴영역 검출기법을 제안한다. 제안한 알고리즘은 연속된 두개의 연속 영상에서 에지 차영상을 구하고 연속적으로 입력되는 영상과의 차분 누적영상을 통해 초기 얼굴영역을 검출한다. 초기 얼굴영역으로부터 외부 조명의 영향을 없애기 위해, 검출된 초기 얼굴영역의 수평 프로파일을 이용하여 수직 방향으로 객체영역을 이분하며, 각각의 객체영역에 관해 주색상 밝기를 구한다. 배경과 잡음 성분을 제거한 후, 분할된 얼굴영역을 통합한 주색상 밝기 분포를 이용하여 타원으로 근사화 함으로써 정확한 얼굴의 기울기와 영역을 실시간으로 계산한다. 제안된 방법은 다양한 조명조건에서 얻어진 동영상을 이용하여 실험되었으며 얼굴의 좌 우 기울기가 $30^{\circ}$이하에서 우수한 얼굴영역 검출 성능을 보였다.

• 디지털콘텐츠학회 논문지
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• 제2권1호
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• pp.21-30
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• 2001

본 논문에서는 분산환경에서 MVC(Model View Controller) 모델을 기반으로 하는 Model 2 프레임 웍에 입각하여 소프트웨어 컴포넌트와 관련된 요소를 자동 생성하여 웹 애플리케이션 구축을 지원하는 방법에 대해 제시한다. Model 2 프레임웍은 웹 애플리케이션에서 Model, View, Controller를 이용하여 MVC 구조로 작성하는 방법으로 기능을 캡슐화하여 변경에 대해 영향을 최소로 하는 구조이기 때문에 확장성, 유지보수성 면에서 좋은 방법으론 인식되고 있다. Model 2 프레임웍 하에서 소프트웨어 컴포넌트와 관련된 요소를 자동 생성하기 위해 MVC 모델, 컴포넌트, Model 2 프레임웍, 디자인 패턴 등에 대해 살펴보고 구현 환경에 적용하기 위한 개선된 Model 2 프레임웍을 제시하고 제시된 프레임웍에 기반하여 소프트웨어 컴포넌트와 관련된 요소를 자동 생성하는 시스템을 설계하고 구현한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.470-473
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• 2000

Digital watermarking is a technical solution to the copyright problem and is a necessary technique to protect copyright of multimedia content. Recently, there are many digital watermarking methods that deal in grey scale still images. However, only a few researchers are interested in digital watermarking fro video and color images. In this paper, we focus on digital watermarking for color images. At first, in order to embed the watermark signal in color image, we converted RGB color space to YCbCr color space which is a world-wide digital component video standard. In addition, we adopted the acceptable degree of color difference in order to keep the invisibility.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.407-410
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• 2003

We propose a new logo watermark scheme for digital images which embed a watermark by modifying middle-frequency sub-bands of wavelet transform. Independent component analysis (ICA) is introduced to authenticate and copyright protect multimedia products by extracting the watermark. To exploit the Human visual system (HVS) and the robustness, a perceptual model is applied with a stochastic approach based on noise visibility function (NVF) for adaptive watermarking algorithm. Experimental results demonstrated that the watermark is perfectly extracted by ICA technique with excellent invisibility, robust against various image and digital processing operators, and almost all compression algorithms such as Jpeg, jpeg 2000, SPIHT, EZW, and principal components analysis (PCA) based compression.

• 음성과학
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• 제12권3호
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• pp.79-89
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• 2005

Acoustic feedback between microphone and receiver can be effectively cancelled adaptive feedback cancellation algorithm. Although many speech sounds have non-Gaussian distribution, most algorithms were tested with speech like sounds whose distribution were Guassian type. In this paper, we proposed an adaptive feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aid. The algorithm was tested with not only Gaussian distribution but also Laplacian distribution. We verified that the proposed algorithm has better acoustic feedback cancelling performance than conventional normalized root mean square (NLMS) algorithm, especially speech like sounds with Laplacian distribution.

• 한국안전학회지
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• 제6권2호
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• pp.21-30
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• 1991

In this paper, we study effect of waveness at the optical surface roughness measurement. In generally, waveness components cause errors in calculation of the roughness value of metal surface. We study about surface roughness signals In the frequency domain for separate two signal component of real roughness and waveness by digital signal processing methods. Thereafter, determine low and high Component of frequency spectrum. By this separating frequency value we design liner low and high pass filter which cutoff frequency is 1 Hz. After this process, converted each filtered spectrum by inverse discrete fourier transformation to time domain waveness and real roughness signals We calculate surface roughness value from filtered roughness signals. For evaluate this method, we use five specimens roughness signal which obtained from optical surface roughness measuring system in 3mm/s moving speed with 0.1 mm laser beam spot size As a result, we obtain more linerized roughness value than that of unfiltered roughness signals.