• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.229-237
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• 2002

Natural synthesis of real and virtual images is a key technology in mixed reality. For this purpose, we propose an efficient dense disparity estimation algorithm and a synthesis algorithm considering features of stereo images. Dense disparities are estimated hierarchically from the low to high resolution images. In the process, the region-dividing-bidirectional-matching algorithm makes matching process efficient and keeps the reliability of the estimated disparities, and dense disparities are assigned considering edge information. finally, mixed reality stereo images are synthesized by comparing depth data of real and virtual Images. Computer simulation shows that the proposed algorithms estimate very stable disparity vectors with sharp edge and synthesize natural stereo mixed reality images.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.149-152
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• 2003

기존의 양안식 스테레오 디스플레이 시스템은 장면 내에 매우 큰 변이를 가지는 물체가 존재 할 경우에 시각피로를 유발하여 오랜 시간동안 시청하기가 어렵게 된다. 본 논문에서는 변이 기반 비대칭 필터링 기법을 제안하고, 이 기법의 시각 피로도에 미치는 영향을 주관적 평가를 통하여 고찰하며, 아울러 교차변이(crossed disparity) 및 비교차변이(uncrossed disparity)에 따른 시각 피로도에 미치는 영향의 변화 또한 고찰하였다. 실험 결과, 변이기반 비대칭 필터링은 시각 피로의 측면에서는 비교차변이만 존재하는 영상의 경우에는 원래의 스테레오 영상에 비해 큰 영향이 없거나, 오히려 필터링 수준에 따라 오히려 시각적 피로가 심하게 되는 결과를 나타내었다. 또한 교차변이의 경우에는 시파피로가 필터링 수준을 높임에 따라 조금씩 시각피로가 개선되는 결과를 나타내었다. 따라서, 비대칭 필터링에 의한 시각피로의 개선효과는 스테레오 영상 내 변이 종류와 그 크기, 시청자의 주시전 등 여러 요인에 따라 달라질 수 있음을 앞 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.56-65
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• 2009

Stereoscopic images consist of the left image and the right image. Thus, stereoscopic images have much amounts of data than single image. Then an efficient image compression technique is needed, the DPCM-based predicted coding compression technique is used in most video coding standards. Motion and disparity estimation are needed to realize the predicted coding compression technique. Their performing algorithm is block matching algorithm used in most video coding standards. Full search algorithm is a base algorithm of block matching algorithm which finds an optimal block to compare the base block with every other block in the search area. This algorithm presents the best efficiency for finding optimal blocks, but it has very large computational loads. In this paper, we have proposed fast disparity estimation algorithm using motion and disparity vector information of the prior frame in stereo image coding. We can realize fast disparity vector estimation in order to reduce search area by taking advantage of global disparity vector and to decrease computational loads by limiting search points using motion vectors and disparity vectors of prior frame. Experimental results show that the proposed algorithm has better performance in the simple image sequence than complex image sequence. We conclude that the fast disparity vector estimation is possible in simple image sequences by reducing computational complexities.

• Journal of KIISE:Software and Applications
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• v.33 no.1
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• pp.69-83
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• 2006

This paper describes an image disparity estimation method using a segmented-region based stereo matching. Segmented-region based disparity estimation yields a disparity map as the unit of segmented region. However, there is a problem that it estimates disparity imprecisely. The reason is that because it not only have matching errors but also apply an identical way to disparity estimation, which is not considered each type of matched regions. To solve this problem, we proposes a disparity estimation method which is considered the type of matched regions. That is, the proposed method classifies whole matched regions into similar-matched region, dissimilar-matched region, false-matched region and miss-matched region by analyzing the type of matched regions. We then performs proper disparity estimation for each type of matched regions. This method minimizes the error in estimating disparity which is caused by inaccurate matching and also improves the accuracy of disparity of the well-matched regions. For the purpose of performance evaluations, we perform tests on a variety of scenes for synthetic, indoor and outdoor images. As a result of tests, we can obtain a dense disparity map which has the improved accuracy. The remarkable result is that the accuracy of disparity is also improved considerably for complex outdoor images which are barely treatable in the previous methods.

• KSBB Journal
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• v.9 no.1
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• pp.16-25
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• 1994

Sporulation mutants of Bacillus subtilis were developed for overproduction of heterologous proteins. The strains spoOJ spoIIG, and spoOJ spoIIG double mutant were constructed from two pretense-delfted mutant (DB104). The vector containing aprE gene was integrated in the chromosome of each strain, then the morphology of each strain was observed by TEM (trasmission electron microscopy). The morphology of spoOJ mutant and spoIIG mutant coincides with the description of the previous reports, respectively. The sporulating cells of spoOJ SpoIIG double mutation resemble spoIIG mutant more similarly, but with a little rougher cell wall membrane. The spoOJ mutation in B. subtilis gives negative effect on aprE activity with only a decreased sporulation frequency. On the contrary spoIIG mutation increases the aprE activity twice with an undetectable sporulation frequency. In the case of spoOJ and spolIG, i. e. double mutation, the effect of spoOJ on aprE activity seems to be relieved and the double mutant shows more or less the same aprE activity compared to spoIIG mutant.

• Journal of The Korean Association For Science Education
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• v.31 no.1
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• pp.32-47
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• 2011

The purpose of this study was to analyze the ability to control variables and the ways by which variables are controlled. First, the assessment criteria for evaluating the students' ability to control variables were developed for 8th grade students. Second, the ways variables are controlled were classified from student activity reports. These students' answers were categorized into six types (type A~ type F). Type A is defined as the group that excelled in recognizing the importance of controlling variables, eliminating unnecessary variables and identifying manipulated, dependent and controlled variables. Third, the scores of ability to control variables (CV score) and the classroom test of scientific reasoning (Lawson SRT) scores were measured. The results indicated that the CV score was highly correlated with Lawson SRT scores (r=.67, p<.01). Therefore, the assessment criteria developed in this study was used to evaluate the ability to control variables (CV score) and to measure the students' scientific reasoning.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.234-239
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• 2021

The purpose of this paper is to find out the nature of language variation by exploring the ways of the progress of the language variation that produces all English-lects, i.e., the World Englishes. The study of language variation in linguistics is a hybrid enterprise, so the study of World Englishes has led to the recognition of a highly diverse set of all English-lects, encompassing regional dialects, sociolects, ethnolects and (post-)colonial dialects of World Englishes. In this paper, we propose a hybrid language variation model with three interacting factors of social distancing, on/off-contact, and linguistic diversity to examine the characteristics of language variation. In the context of World Englishes, the social distance is typically low in terms of their local location (country/speech) for local purposes. The social distance also varies based on online/offline communication modes and other social factors like gender, age and ethnic groups, resulting in all English-lects. To clarify the nature of World Englishes, the core Englishes, BrE, AmE and CanE are discussed here.

• The Journal of the Acoustical Society of Korea
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• v.10 no.2
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• pp.29-35
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• 1991

In this paper, we discuss the method of recognizing allophone unit isolated words using hidden Markov model(HMM). Frist we constructed allophone lexicon by extracting allophones from training data and by training allophone HMMs. And then to recognize isolated words using allophone HMMs, it is necessary to construct word dictionary which contains information of allophone sequence and inter-allophone transition probability. Allophone sequences are represented by allophone HMMs. To see the effects of inter-allophone transition probability and to determine optimal probabilities, we performend some experiments. And we showed that small number of traing data and simple train procedure is needed to train word HMMs of allophone sequences and that not less performance than word unit HMM is obtained.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.142-147
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• 1975

The varietal variations of protein and amylose content of rice grown at field and green house were studied. The protein content was negatively correlated with growth duration, and the amylose content was positively correlated with heading date. The environmental variation of the amylose content by cultural season and year was greater in the low amylose varieties than in the high amylose one.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.763-765
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• 2004

본 연구는 간경변을 보유한 환자의 복부 CT 영상을 이용하여 비장의 웨이브 패턴(wave pattern)을 관찰하였는데 정상간을 보유한 환자의 복부 CT 영상과 차이가 있음을 발견하였다. 본 논문은 관찰된 두 가지 원리를 바탕으로 복부 CT 영상에서 비장의 웨이브 패턴을 이용하여 간경변을 효과적으로 진단하는 새로운 방법을 제시한다. 본 논문에서 실험에 사용한 영상들의 경우에 꼬리엽과 우엽의 비율로써 간경변을 보유한 영상임을 알 수 있는 경우에는 모두 비장의 웨이브 패턴 테스트들로써 간경변 보유 판정 결과를 얻었다. 이는 꼬리엽과 우엽의 비율 테스트를 생략하고 비장만으로 간경변 보유간을 판정해 낼 수 있음을 말해주는 것이다.