• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.55-62
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• 1997

본 논문에서는 윤곽선의 다각근사화시 발생하는 오차신호를 표본화하고 표본화된 신호를 부호화하기 위한 새로운 변환을 제안한다. 제안하는 방법은 다각근사화시 발생하는 윤곽선의 단편들이 완만한 곡선의 형태를 갖고 양 끝점이 0이라는 특징을 고려해서 르장드르 다항식에 기반한 새로운 변환을 제안한다. 제안한 방법은, 기존의 방법인 이산여현변환, 이산정현변환 등과 변환부호화 이득면에서 비교해 볼 때 우수한 결과를 얻었다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.10-21
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• 2013

This study suggested combined filtering model to eliminate outlier travel time data in transportation information system, and it was based on Median Absolute Deviation and Voting Rule. This model applied Median Absolute Deviation (MAD) method to follow normal distribution as first filtering process. After that, Voting rule is applied to eliminate remaining outlier travel time data after Median Absolute Deviation. In Voting Rule, travel time samples are judged as outliers according to travel-time difference between sample data and mean data. Elimination or not of outliers are determined using a majority rule. In case study of national highway No. 3, combined filtering model selectively eliminated outliers only and could improve accuracy of estimated travel time.

• The Korean Journal of Mycology
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• v.43 no.4
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• pp.216-223
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• 2015

Amanita subgenus Lepidella is a well-known group that includes lethal amanitas. However, the taxonomic investigation of Korean Amanita species is still in progress. In this study, we collected Amanita specimens in Korea from 2009 to 2015 and classified 22 of them as subgenus Lepidella based on the morphology. Phylogenetic analysis of the 22 Amanita specimens based on the internal transcribed spacers sequences identified 16 phylogenetic species which included three undescribed Amanita species (A. sepiacea, A. modesta and A. kotohiraensis). Microscopic features of newly recorded Amanita species were photographed and line drawings were made. All collections cited here are deposited in the Herbarium Conservation Center of the National Institute of Agricultural Sciences.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.597-606
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• 2010

This paper describes a real-time camera tracking framework specifically designed to track a monocular camera in an AR workspace. Typically, the Kalman filter is often employed for the camera tracking. In general, however, tracking performances of conventional methods are seriously affected by unpredictable situations such as ambiguity in feature detection, occlusion of features and rapid camera shake. In this paper, a recursive Bayesian sampling framework which is also known as the particle filter is adopted for the camera pose estimation. In our system, the camera state is estimated on the basis of the Gaussian distribution without employing additional uncertainty model and sample weight computation. In addition, the camera state is directly computed based on new sample particles which are distributed according to the true posterior of system state. In order to verify the proposed system, we conduct several experiments for unstable situations in the desktop AR environments.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.212-213
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• 2013

압축 센싱 기술은 성긴 (sparse)신호의 경우 Nyquist 표본화율보다 적은 수의 표본으로도 원신호를 완벽하게 복원할 수 있는 이론을 제시하고 있다. 전통적인 영상 처리분야에 압축 센싱 기술을 적용하는 연구를 시작함에 따라 계산 복잡도 및 메모리 문제로 블록 영상 기반 압축 센싱 방법을 많이 고려하고 있다. 또한, 이러한 압축 센싱 방법에서 복원 과정은 일정 허용 오차 범위 기준을 복원 신호가 만족시키는 경우에 종료되므로, 허용 오차 범위에 따른 복원 신호 품질과 계산 복잡도에 변화가 발생하게 된다. 본 논문에서는 블록 기반 압축 센싱 방법을 이용하여 영상을 복원함에 있어, 허용 오차 값에 따른 복원 영상의 화질 변화와 시간 절감 정도를 비교, 분석하였다.

• Proceedings of the Korean Statistical Society Conference
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• 2001.11a
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• pp.115-120
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• 2001

라틴 하이퍼큐브 실험계획은 전산실험을 위하여 Mckay, Beckman과 Conover(1979)에 의해 고안된 방법으로 실험을 한번 시행하는데 많은 시간과 비용이 들거나 인자가 많은 실험에 효율적으로 사용할 수 있다. 하지만 이 실험계획 역시 실험영역 전체에서 골고루 배치되지 않을 가능성이 있으므로 이를 보완하려는 시도가 이루어져 왔으며, 여기서는 good lattice points(glp)와 계통추출을 응용하여 격자기반(lattice-based) Lhd의 두 가지 방법을 제안하였다. 모의실험 결과 glp 실험계획을 응용한 "방법 1"은 모형을 가정한 엔트로피에 기초한 최적 기준으로 검토한 경우 우수하였다. "방법 2"는 표본조사에 널리 쓰이는 계통추출을 응용하였으며 입력변수가 각기 다른 9개의 실험함수에 관하여 표본 평균의 추정치와 분산, MSE를 비교한 결과, 다른 실험계획들보다 우수하였다. 이 결과는 실험점이 실험영역 전체에서 골고루 퍼져서 나타난 것으로 보이며, 향후 전산실험계획에서의 응용을 기대할 수 있다.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.135-145
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• 2008

As a fundamental input to the travel demand forecasting, OD has been always a concern in obtaining the accurate link traffic volume. Numerous methods were applied thus far without a complete success. Some existing OD estimation techniques generally extract regular samples and expand those sample into population. These methods, however, leaves some to be desired in terms of accuracy. To complement such problems, research on estimating OD using additional information such as link traffic volume as well as sample link use rate have been accomplished. In this paper, a new approach for estimating static origin-destination (OD) using probe vehicle has been proposed. More specifically, this paper tried to search an effective sample rate which varies over time and space. In a sample test network study, the traffic volume error rate of each link was set as objective function in solving the problem. As a key result the MAE (mean absolute error) between expanded OD and actual OD was identified as about 5.28%. The developed methodology could be applied with similar cases. Some limitations and future research agenda have also been discussed.

• The Korean Journal of Applied Statistics
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• v.30 no.2
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• pp.301-309
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• 2017

It is often possible to test for differences in population means when two or more samples are extracted from each N population. However, it is not possible to test for the mean difference if one sample is extracted from each population since a sample mean does not exist. But, by dividing a group of samples extracted one by one into two groups and generating a sample mean, we can identify a heterogeneity that may exist within the group by comparing the differences of the groups' mean. Therefore, we propose a minimum combination t-test method that can test the mean difference by the number of combinations that can be divided into two groups. In this paper, we proposed a method to test differences between means to check heterogeneity in a group of extracted samples. We verified the performance of the method by simulation study and obtained the results through real data analysis.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1021-1029
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• 2010

In 2009 the former three surveys on small and medium enterprises were combined into one survey to reduce the response burden of enterprises. In this report, we study a sample design for 2009 survey on actual state of small and medium enterprises (SMEs). However, the differences between the manufacturing industries and knowledge-based service industries are so large that we need to consider separate populations in the survey. The total sample size is decided as 10,000 in new survey design for integration. We allocate the sample sizes for the first stratum based on CV and then allocate the sample sizes for the second stratum using root proportional formula. Also we calculate survey weights and propose the formula for the estimators as well as standard errors using weights for each characteristic.

• Korean Journal of Plant Taxonomy
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• v.33 no.4
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• pp.455-472
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• 2003

The period from 1946 until his retirement from Department of Forest Resources, Seoul National University was a time of research and professional activity on many fronts for Korean Plant Taxonomy. From 1952 to 1984, he travelled south Korea and collected more than 70,000 specimens. Working out of this project, Dr. Lee developed the SNUA herbarium (Herbarium of The Arboretum of Seoul National University) as the best University herbarium in Korea for the modem floristic work. Dr. Lee's first interest rests on his contributions to our understanding of the twig identification in early 1950. Asian deciduous oak taxa have attracted particular focus to him late 1950 and early 1960. Accordingly Dr. Lee has been one of the specialists on systematic study of Asian oak which is a basis of identification in eastern Asia now. Dr. Lee's contributions concerning rare and endangered plants in Korea provide a tremendous information after a Japanese taxonomist, T. Nakai did in early 1920 to late 1930 in Korea. During his fourteen year career from 1970 to 1984, Dr. Lee spent time to investigate flora of many local and National Park sites. Much of his effort was directed to the voucher specimens for which he worked for the Illustrated Flora of Korea and also served as a field collector. These collections at SNUA enabled us to extend our educational outreach from the local to the national flora research. Although Dr. Lee has been and continues to be the soul of SNUA, collection records about his purpose and aim for each trip are not well documented except date and field studied sites. This lesson enables us to tackle the same issue of balancing quantity and quality with well documented specimens now.