• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.246-251
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• 1999

This study was designed to evaluate the mutagenicity and the primary mutagenic mechanism of chloropropanols by using various genotypes of E. coli WP2, E. coli TK and E. coli GW series strains. Chloropropanols showed the low mutagenic activities in E. coli WP2s and WP2 establishing the following order; 2,3-DCP> 3-MCPD>1,3-DCP. As compared with E. coli WP2s, the decrease of mutagenic activity and the increase of survival rate in E. coli WP2 $(WP2s\;uvrA^+)$ suggest that DNA lesions produced by chloropropanols could be easily removed by excision-repair system. From the diminution of mutagenic activity and survival rate in E. coli CM611 (WP2s lexA), it was confirmed that the mutagenesis by chloropropanols was dependent on the SOS-repair system. This fact could be also confirmed from the result that both the mutagenic activity and survival rate in E. coli TK610 (umuC) were much lower than those in E. coli TK603 $(umuC^+)$. In the experiment to examine the possibility that chloropropanols might have effects on the LexA of SOS response negative regulator, there was no variation in ${\beta}-galactosidase$ activities of E. coli GW1105 $[lexA3\;(Ind^-)]$ and GW1107 [lexA51 (Def)] by addition of the compounds, indicating that chloropropanols do not have any effects on the LexA, itself.

• Journal of the Korean Mathematical Society
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• v.57 no.3
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• pp.777-792
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• 2020

We introduce the fractal expansions, sequences of integers associated to a number. We show that these sequences characterize the O-sequences and encode some information about lex segment ideals. Moreover, we introduce numerical functions called fractal functions, and we use them to solve the open problem of the classification of the Hilbert functions of any bigraded algebra.

• Korean Journal of Cognitive Science
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• v.1 no.1
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• pp.103-127
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• 1989

Learning systems by using examples have been developed which include ALEX, LP, and LEX.Specially Silver's LP systems suggerts the method to use a seyuence of operators, which was applied to the worked example, to sove a symbolic equation.This paper presents the new learning system, called LRD, in which generalization and discrimination steps are suggerted to solv all the problems similar to the worked example.The system LRD is illustrated by the problem of finding the ranges of transcendentral functions and compared to LP and LEX by the problems discussed in them.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2109-2114
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• 2003

The vortex flow characteristics of a yawed LEX-delta wing at a high-angle of attack are studied using a computational analysis. The objective of the present study is to investigate and visualize the effects of the yaw angle, the development and interaction of vortices, the relationship between the suction pressure distributions and the vortex flow characteristics. Computations are applied to the three dimensional, compressible, Navier-Stokes Equations. In computations, the yaw angle is varied between 0 and 20 degree at a high-angle of attack. Computational predictions are compared with the previous experimental results.

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.15-23
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• 2004

The present study is aimed to achieve dynamic visualization from the in-house 3-D stereoscopic PIV to represent quantitative flow information such as time-resolved 3-D velocity distribution, vorticity, turbulent intensity or Reynolds stresses and so on. One of the application of the present study is Leading edge extension(LEX) flow appearing on modern delta wing aircraft. The other is mixing flow in stirring tank used in industry field. LEX in a highly swept shape applied to a delta wing features the modern air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present method resolves also the complicated flow patterns of two type impellers rotating in stirring vessel. Flow quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing visualization. And it makes the easy understanding of the unsteady flow characteristics of the typical industrial mixers.

• Korean Journal of Microbiology
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• v.30 no.5
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• pp.371-376
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• 1992

Plasmid pSL4 of plasmid pKM 101 mutant have high protection effects and mutagenecity for UV and methyl methanesulfonate, The mucA gene and a pan of mucE gene of pKM 101 and pSL4 were sucloned onto lacZ' fusion vector pMC874 and the hybrid plasmids pBH31 and pBH30 were selected. These plsmids were intrduced into $recA^{+}lexA^{-}$, $recA^{-}와lexA^{+}$ strains and determined the activity of $\beta$-galactosidase for UV. In $recA^{+}lexA^{+}$ strain.$\beta$-galactosidase activity of pBH30 included mue region of pSL4 was higher thall pBH31 inclued muc region of pKM 10 I and the tf-galactosidase of two plasmids was not induced in reeA and leeA mutants with or without UV illumination. Without UV illumination. the .$\beta$-galactosidasc of pBH30 was expressed a little higher level than that of pBH3L We suggest that the functional difference of pKM 10l and pSL4 are due to the variety of mue regulatory region. Also. a plasmid pBH 100 earring umuC' -lacZ' gene fusion was constructed in vitro to study the regulation of the umu operon. It was shown that the umu operon is induced by UV and is regulated by the reeA and lexA genes.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.215-224
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• 2001

An experimental investigation was conducted on the interaction of vortices over a delta wing with the leading edge extension for three angles of attack($16^{\circ},\; 24^{\circ} \;and\; 28^{\circ}$) at Reynolds number of $1.76{\times}10^6.$ The experimental data included total pressure contours and velocity vectors using 5-hole probe measurements. Constant total pressure coefficient contours show the LEX vortex moves downward and outboard, while the wing vortex exhibited an inboard and upward migration. At near the trailing edge, these vortices reveal a direct interaction between the wing and LEX vortex, featuring a coiling of vortex cores about each other. The combined effect of the interaction of these two vortices and proximity to the wing surface results in the increase of the suction peak. This is in contrast to the result obtained on the delta wing alone configuration, where the effect of the vortex breakdown was manifested. The interaction of the wing and LEX vortices is more pronounced at higher AOA.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2151-2156
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• 2003

The distinguishing features of flows at high angles of attacks are caused by the generation of free shear layers at sharp leading edges, by separation of the viscous layers from the surfaces of wings and bodies and by the flow in the wakes of the wings and bodies. In this study, systematic approach by PIV experimental method within a circulating water channel was adopted to study the fundamental characteristics of induced vortex generation, development and its breakdown appearing on a delta wing model with or without LEX in terms of four angles of attack($15^{\circ}$, $20^{\circ}$, $25^{\circ}$, $30^{\circ}$) and six measuring sections(30%, 40%, 50%, 60%, 70%, 80%) of chord length. Distributions of time-averaged velocity vectors and vorticities over the delta wing model were compared along the chord length direction. Highly swept leading edge extension(LEX) applied to delta wings has greatly improved the subsonic maneuverability of contemporary fighters. High-speed CCD camera which made it possible to acquire serial images is able to get the detailed information about the flow characteristics occurred on the delta wing. Especially quantitative comparison of the maximum vorticity featuring the induced pressure distribution were also conducted to clarity the significance of the LEX existence.

• Language and Information
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• v.14 no.1
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• pp.165-196
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• 2010

The primary goal of this paper is to propose methods of enriching two heterogeneous ontologies: Sejong Semantic Classes (SJSC) and KorLexNoun 1.5 (KLN). In order to achieve this goal, this study introduces the pros and cons of two ontologies, and analyzes the error patterns found during the fine-grained manual mapping processes between them. Error patterns can be classified into four types: (1) structural defectives involved in node branching, (2) errors in assigning the semantic classes, (3) deficiency in providing linguistic information, and (4) lack of the lexical units representing specific concepts. According to these error patterns, we propose different solutions in order to correct the node branching defectives and the semantic class assignment, to complement the deficiency of linguistic information, and to increase the number of lexical units suitably allotted to their corresponding concepts. Using the results of this study, we can obtain more enriched ontologies by correcting the defects and errors in each ontology, which will lead to the enhancement of practicality for syntactic and semantic analysis.

• Annual Conference on Human and Language Technology
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• 2008.10a
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• pp.42-47
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• 2008

1980년대 중반부터 지난 20여 년간 구축해 온 영어 워드넷(PWN)은 인간의 심상어휘집을 재현하려는 목적으로 개발되기 시작하였으나, 그 활용 가능성에 주목한 것은 자연언어처리와 지식공학 분야다. 컴퓨터 매개 의사소통(CMC), 인간-컴퓨터 상호작용(HCI)에서 인간 언어를 자연스럽게 사용하여 필요한 정보를 획득하기 위해서는 의미와 지식의 처리가 필수적인데, 그 해결의 실마리를 어휘라는 실체를 가진 언어단위에서 찾을 수 있기 때문이다. 이후 전 세계적으로 약 50개 언어의 어휘의미망이 PWN을 참조모델로 구축되어 다국어처리의 기반을 제공할 뿐 아니라, 시맨틱 웹 이후 더욱 주목 받고 다양한 방식으로 활용되고 있다. 본고는 PWN을 참조 모델로 2004년부터 2007년까지 구축한 한국어 어휘의미망 KorLex 1.5를 소개하는 데 있다. 현재 KorLex은 명사, 동사, 형용사, 부사 및 분류사로 구성되며, 약 13만 개의 신셋과 약 15만 개의 어의를 포함하고 있다.