• 경영과학
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• 제23권1호
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• pp.63-74
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• 2006

Decision tree induction algorithm is one of the most widely used methods in classification problems. However, they could be trapped into a local minimum and have no reasonable means to escape from it if tree algorithm uses top-down search algorithm. Further, if irrelevant or redundant features are included in the data set, tree algorithms produces trees that are less accurate than those from the data set with only relevant features. We propose a hybrid algorithm to generate decision tree that uses genetic programming with sequentially selected features. Correlation-based Feature Selection (CFS) method is adopted to find relevant features which are fed to genetic programming sequentially to find optimal trees at each iteration. The new proposed algorithm produce simpler and more understandable decision trees as compared with other decision trees and it is also effective in producing similar or better trees with relatively smaller set of features in the view of cross-validation accuracy.

• Journal of Plant Biology
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• 제11권4호
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• pp.21-29
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• 1968

It may be fully known that Korea is the main producing country of pine tree form the pan-Asian viewpoint of the geographical distribution of the pine tree. Through the study on the reason why the pine tree became a tree of the maximum cover degree in Korea and the observation of natural preservation status of all sorts of trees in the DMZ area for nearly 20 years after the Korean Armistice, it has come to know that almost all of the pine tree were banished. This phenomenon has been resulted by the ecological characteristics of the pine tree itself which has no sprouting power at all, war disasters, deforestation and incendiary fire that have been steadily occurred until now since the time of Armistice.

• 반도체디스플레이기술학회지
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• 제8권1호
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• pp.43-48
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• 2009

We have examined the problem of the number of quad-tree blocks that an n-dimensional rectangle will be decomposed into on the average. the contribution of this paper are both practical and theoretical. In this paper, we develops the overlapping multi-scale models and the region quad-tree models which is useful in computer graphics animation, image processing, pattern recognition and also for modeling three dimensional objects. These models, which represent something of a conceptual departure from other models developed for multi-scale framework were developed with the specific interest of producing smooth estimates.

• 문화기술의 융합
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• 제5권4호
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• pp.283-288
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• 2019

수강생들의 정보와 경험 부족을 극복하기 위해, 의사 결정 트리를 활용한 콘텐츠 기획 트리를 개발하였다. 콘텐츠 기획 트리는 수강생들이 개발할 주제와 스토리를 선택하는 나무 몸통 생성단계, 해당 스토리를 바탕으로 개발 가능한 형태 '범주'를 선택하는 부모 가지 생성단계, 해당 콘텐츠를 효과적으로 제작하는 흥미 '효과'를 선택하는 자식가지 생성단계 그리고 시각화할 멀티미디어 표현 '요소'를 선택하는 잎사귀 생성단계로 구성된다. 교육 모델은 게임기획 디자인과 정보시각화 강의에 적용되었고, 각 강의에서 사용된 범주, 효과 그리고 요소의 예를 사례로 제시한다. 교육 모델은 145개 팀 프로젝트에 사용되었고, 단계별 학습 프로세스로 효율성을 확인하였다.

• 한국건설순환자원학회지
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• 제5권2호
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• pp.42-49
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• 2010

• 전자공학회논문지CI
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• 제47권5호
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• pp.25-34
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• 2010

스타이너 포인트들을 추가하여 모든 입력 노드들을 최단 길이로 연결하는 스타이너 최소 트리는 최소 신장 트리에 비해 전체 길이는 짧으나, 그것을 생성하는 문제는 NP-Complete 영역에 속한다. 이 문제를 위한 휴리스틱들은, 입력 노드의 수가 매우 큰 경우에는 많은 시간과 계산을 요구한다. 본 논문에서는 많은 입력 노드에 대해, 최하위 계층에서 포탈을 이용한 모든 가능한 단위 스타이너 트리들을 생성하고 각 상위 계층에서 이들을 계층별 병합 처리하여 최상위 계층에서 최소 비용의 트리를 선택하는 효과적인 PTAS 기법을 제안한다. 16,000개의 입력 노드와 최하위 계층에서 16개의 단위 영역으로 설계된 실험에서 생성된 PTAS 스타이너 트리는, pure 스타이너 트리의 길이에 비해 길이가 0.24% 증가되었으나, 생성 시간은 직렬 처리는 85.4%, 병렬처리는 98.9% 개선되었다. 따라서 제안하는 PTAS 스타이너 트리 생성 기법은 많은 입력 노드들에 대해 근사 스타이너 트리를 신속히 생성하는 응용에 잘 적용될 수 있을 것이다.

• 한국균학회지
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• 제20권2호
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• pp.144-148
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• 1992

야생(野生) 버섯 중(中) 송이의 대표적 발생지(發生地)인 전북(全北) 남원(南原) 지역(地域)에서 식생(植生) 및 주요(主要) 야생(野生)버섯 분포(分布)를 조사(調査)한 결과(結果)는 다음과 같다. 송이 발생지(發生地)에서 식생(植生)의 출현종수(出現種數)는 $11{\sim}29$종(種)이었으며 교목층(喬木層)(Tl, T2)에서는 소나무(Pinus densiflora S. et. Z.), 관목층(灌木層)(S)에서는 진달래(Rhododendron mucronulatm TURCZ), 졸참나무(Quercus serrata THUNB.), 초목층(草木層)(H)에서는 산거울(Carex humilis LEYss.)이 우고(優古)하고 있었다. 송이 발생지(發生地)의 주요(主要) 야생(野生) 버섯 분포(分布)는 그물버섯과(科)(Boletaceae)에 속하는 평원비단그물버섯(Suilus Placidus Bon. Sing.)과 싸리버섯과(科)(Ramariaceae)에 속하는 싸리버섯(Ramaria botrytis Fr. Ricken) 등(等)이 주종(主從)을 이루었다.

• Journal of Microbiology
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• 제44권6호
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• pp.591-599
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• 2006

To address the diversity of cyclodextrin-producing P. graminis strains isolated from wheat roots and rhizospheres of maize and sorghum sown in Australia, Brazil, and France, restriction fragment length polymorphism analysis of part of genes encoding RNA polymerase (rpoB-RFLP) and DNA gyrase subunit B (gyrB-RFLP) was used to produce genetic fingerprints. A phylogenetic tree based on rpoB gene sequences was also constructed. The isolates originated from Brazil could be separated from those from Australia and France, when data from the rpoB-based phylogenetic tree or gyrB-RFLP were considered. These analyses also allowed the separation of all P. graminis strains studied here into four clusters; one group formed by the strains GJK201 and $RSA19^T$, second group formed by the strains MC22.02 and MC04.21, third group formed by the strains TOD61, TOD 221, TOD302, and TOD111, and forth group formed by all strains isolated from plants sown in Cerrado soil, Brazil. As this last group was formed by strains isolated from sorghum and maize sown in the same soil (Cerrado) in Brazil, our results suggest that the diversity of these P. graminis strains is more affected by the soil type than the plant from where they have been isolated.

• 한국미생물·생명공학회지
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• 제51권4호
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• pp.403-415
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• 2023

This study aimed to isolate and identify L-(+)-lactic acid-producing bacteria from tree barks collected in Thailand and evaluate the potential strain as probiotics. Twelve strains were isolated and characterized phenotypically and genotypically. The strains exhibited a rod-shaped morphology, high-temperature tolerance, and the ability to ferment different sugars into lactic acid. Based on 16S rRNA gene analysis, all strains were identified as belonging to Weizmannia coagulans. Among the isolated strains, BKMTCR2-2 demonstrated exceptional lactic acid production, with 96.41% optical purity, 2.33 g/l of lactic acid production, 1.44 g/g of lactic acid yield (per gram of glucose consumption), and 0.0049 g/l/h of lactic acid productivity. This strain also displayed a wide range of pH tolerance, suggesting suitability for the human gastrointestinal tract and potential probiotic applications. The whole-genome sequence of BKMTCR2-2 was assembled using a hybridization approach that combined long and short reads. The genomic analysis confirmed its identification as W. coagulans and safety assessments revealed its non-pathogenic attribute compared to type strains and commercial probiotic strains. Furthermore, this strain exhibited resilience to acidic and bile conditions, along with the presence of potential probiotic-related genes and metabolic capabilities. These findings suggest that BKMTCR2-2 holds promise as a safe and effective probiotic strain with significant lactic acid production capabilities.

• International Journal of Ocean System Engineering
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• 제3권3호
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• pp.116-130
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• 2013

The prediction of ocean currents in real time over the warning times of a few hours or days is required in planning many operation-related activities in the ocean. Traditionally this is done through numerical models which are targeted toward producing spatially distributed information. This paper discusses a complementary method to do so when site-specific predictions are desired. It is based on the use of a recurrent type of neural network as well as the statistical tool of model tree. The measurements made at a site in Indian Ocean over a period of 4 years were used. The predictions were made over 72 time steps in advance. The models developed were found to be fairly accurate in terms of the selected error statistics. Among the two modeling techniques the model tree performed better showing the necessity of using distributed models for different sub-domains of data rather than a unique one over the entire input domain. Typically such predictions were associated with average errors of less than 2.0 cm/s. Although the prediction accuracy declined over longer intervals, it was still very satisfactory in terms of theselected error criteria. Similarly prediction of extreme values matched with that of the rest of predictions. Unlike past studies both east-west and north-south current components were predicted fairly well.