• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.113-118
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• 2011

This paper proposes computer visual inspection algorithms for PCB defects which are found in a manufacturing process. The proposed method can detect open circuit and short circuit on bare PCB without using any reference images. It performs adaptive threshold processing for the ROI (Region of Interest) of a target image, median filtering to remove noises, and then analyzes connected components of the binary image. In this paper, the connected components of circuit pattern are defined as 6 types. The proposed method classifies the connected components of the target image into 6 types, and determines an unclassified component as a defect of the circuit. The analysis of the original target image detects open circuits, while the analysis of the complement image finds short circuits. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.130-132
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• 2003

시맨틱 웹의 구현을 가능하게 하는 핵심기술은 도메인 내의 개념들과 개념들 사이의 관계들을 정형적으로 기술한 온톨로지이다. 그러나 온톨로지 생성을 위한 기존 관련연구들의 상당한 부분들은 몇몇의 휴리스틱을 가지는 수작업 형태를 띠고 있다. 기존 연구들의 수작업을 통한 온톨로지 생성은 어려운 작업일 뿐 아니라 시간이 많이 소비되는 문제점을 갖는다. 따라서 본 논문에서는 도메인 온톨로지를 (반)자동으로 생성하는 방법론을 제안한다. 제안한 방법론에서는 데이터마이닝 기법들인 AOI(Attribute-Oriented Induction)와 ID3 알고리즘을 사용한다. 우리는 제안한 접근법이 온톨로지 자동 생성에 있어 실현 가능한 접근법임을 예제로써 증명한다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2453-2455
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• 2003

We propose a path planning method to reduce the inspection time of AOI (automatic optical inspection) machines in SMT (surface mount technology) in-line system. Inspection windows of board should be clustered to consider the FOV (field-of-view) of camera. The number of clusters is desirable to be minimized in order to reduce the overall inspection time. We newly propose a genetic algorithm to minimize the number of clusters for a given board. Comparative simulation results are presented to verify the usefulness of proposed algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.442-446
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• 2010

본 논문에서는 거리변환 기반의 정밀한 fiducial 마크 정렬 알고리즘을 제안한다. 거리변환은 물체의 중심에 가중치를 가지는 특성이 있는데 이는 AOI 공정에서 에칭, 이동과 같은 다양한 요소들로부터 획득되는 타겟영상에 대하여 강인하게 물체의 중심으로 매칭할 수 있도록 한다. 제안한 방법은 우선 입력 타겟영상에 대하여 이진화를 진행하고, 다음 모델과 타겟영상에 대하여 거리변환을 이용하여 거리특징을 추출하고, 추출된 모델과 타겟영상에 대한 거리특징을 NCC(Normalized Cross Correlation)를 이용하여 매칭한 후, 매칭 스코어에 대하여 Sub-pixel 분석을 진행하여 sub-pixel 레벨의 정확도를 가지도록 한다. 실험결과로부터 제안한 거리특징을 이용한 매칭 알고리즘이 기존의 픽셀 밝기 값을 이용한 매칭보다 강인하고 정확하게 매칭됨을 확인할 수 있었다.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1171-1177
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• 2021

Measuring and evaluation of audience's visual message perception are crucial process for scientific production of visual content. This study tried to evaluate the difference of viewer's awareness of visual object depends on his or her inherent characteristics like conservatism using an eye tracker system. Especially, this experiment tested research questions about positive correlation between conservatism and peoples' eye movements following the sound visual messages. 57 subjects participated in the test. Two different groups were exposed to two visual elements representing 'the conservative' and 'the liberal'. The results showed that people tended to have different way of seeing visual objects according to their inherent characteristics. Also by comparing the gaze time at the object and area of interest(AOI) in visual, this study is able to verify the existence of 'positive way of seeing' and 'negative way of seeing'. The two different ways of seeing have their own trail of eye movement.

• Journal of Korea Water Resources Association
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• v.52 no.8
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• pp.575-587
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• 2019

This study evaluated the effect of a mother wavelet in the wavelet analysis of various times series made by combining white noise and/or sine function. The result derived is also applied to short-memory arctic oscillation index (AOI) and long-memory southern oscillation index (SOI). This study, different from previous studies evaluating one or two mother wavelets, considers a total of four generally-used mother wavelets, Bump, Morlet, Paul, and Mexican Hat. Summarizing the results is as follows. First, the Bump mother wavelet is found to have some limitations to represent the unstationary behavior of the periodic components. Its application results are more or less the same as the spectrum analysis. On the other hand, the Morlet and Paul mother wavelets are found to represent the non-stationary behavior of the periodic components. Finally, the Mexican Hat mother wavelet is found to be too complicated to interpret. Additionally, it is also found that the application result of Paul mother wavelet can be inconsistent for some specific time series. As a result, the Morlet mother wavelet seems to be the most stable one for general applications, which is also assured by the recent trend that the Morlet mother wavelet is most frequently used in the wavelet analysis research.

• Journal of Korea Game Society
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• v.9 no.2
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• pp.105-113
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• 2009

The most important service of the online game is the stability. However, in online games, the increase in the number of users burdens the server as thousands of users connect to the server at the same time. While various techniques to reduce the load on the server are studied, the study is limited only to the server part like an improvement of server algorithms. In this paper, a program to handle the largest load of the server, the message synchronization of both the server and client, is designed and implemented.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.488-495
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• 2000

Strain SA72 was isolated from Jeot-gal and identified as producer of a bacteriocin, which showed some bactericidal activity against Lactobacillus delbrueckii ATCC 4797. Strain SA72 was tentatively identified as Lactococcus lactis according to the AOI test. Lactococcus lactis SA72 showed a broad spectrum of microorganisms, tested by the modified deferred method. The activity of lacticion SA72, named tentatively as a bacteriocin produced by Lactococcus lactis SA72, was detected during the mid-lon growth phase, reached a maximum during the early stationary phase, and then declined after the late stationary phase. Lacticin SA72 also showed a relatively broad spectrum of activity against non-pathogenic and pathogenic microorganisms when assessed by the spot-on-lawn method. Its anitimicrobial activity on sensitive indicator cells disappeared completely by protease XIV treatment. The inhibitory activity of lacticin SA72 remained after treatment for 15 min at $121^{\circ}C$, 문 was stable in a pH range of 2.0 to 9.0 and all organic solvents examined. It demonstrated a typical bactericidal mode of inhibition against Lactobacillus delbrueckii ATCC 4797. The apparent molecular mass of lacticin SA72 was in the region of 3-3.5 kDa, determined by SDS-PAGE.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.276-282
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• 2015

This paper proposes a SMD (surface mounting device) classification method for the PCB assembly inspection machines. The package types of SMD components should be classified to create the job program of the inspection machine. In order to reduce the creation time of job program, we developed the automatic classification algorithm for the SMD packages. We identified the chip-type packages by color and edge distribution of the images. The input images are transformed into the HSI color model, and the binarized histroms are extracted for H and S spaces. Also the edges are extracted from the binarized image, and quantized histograms are obtained for horizontal and vertical direction. The neural network is then applied to classify the package types from the histogram inputs. The experimental results are presented to verify the usefulness of the proposed method.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.368-375
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• 2020

In this study, the area of interest(AOI) of Soju ad poster was tracked for analysis the time to frist fixation, the average of fixation duration and count by the study indexes. As a result of the analysis, Visual attention was higher the face than the body shape of the ad model. This means "when we look at printed ads, we see picture elements first, not language one" but language elements can't be overlooked either. Also, the importance of the model role could be verified by measuring the visual attention on the Soju ad poster. Based on the results of this study, if further research on ad posters is carried out and scientific and quantitative interpretation methods are presented, it can be used as product marketing data that can be reflected in ad model selection and poster design.