• Title/Summary/Keyword: MAL

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Dynamic Representations of Parabolas in a Microworld (포물선의 동적 표현과 마이크로월드)

  • Kim, Hwa-Kyung
    • The Mathematical Education
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    • v.47 no.1
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    • pp.49-59
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    • 2008
  • In this paper, we discuss two representations of a curve. One is a static representation as set of points, the other is a dynamic representation using time parameter. And we suggest needs of designing a computer microword where we can represent a curve both statically and dynamically. We also emphasize the importance of translation activity from a static representation to a dynamic representation. For this purpose, we first consider constructionism and 'computers and mathematics education' as a theoretical backgrounds. We focus the curve of a parabola in this paper since this is common in mathematics curriculum and is related to realistic situation such as throwing ball. And we survey the mathematics curriculum about parabola representation. And we introduce JavaMAL microworld that is integrated microworld between LOGO and DGS. In this microworld, we represent a parabola using a dynamic action, and connect this dynamic parabola action to recursive patterns. Finally, we remake a parabola for a realistic situation using this dynamic representation. And we discuss the educational meaning of dynamic representation and its computer microworld.

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Performance of the MMSE Receiver Front-ended by CMA Array in the Mult-path Faded CDMA Forward Link.

  • Lee, Yun-Soo;Chinn, Yong-Oak
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.328-332
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    • 2007
  • The structure of MMSE receiver frontended by CMA array working in CDMA forward link is proposed. By using the despreaded pilot signal of forward link as a reference signal, CMA array can capture multi-path signals securely even in severely faded mobile channel. The remaining MAl (Multiple Access Interference) is cancelled by the cascaded MMSE receiver. Through computer simulation, it is proved that the proposed system shows much better BER performance than any other systems. As a mobile based spatio-temporal receiver, the proposed system also reduces implemental cost and complexity by adopting the simplest algorithm for its spatial and temporal domain processing.

On the Necessity of Cavity-type Coupling Mechanism for obtaining Circular Polarization with Microstrip Patch Antenna

  • Abegaonkar, Mahesh P.;Cho, Young-Ki
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.459-463
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    • 2003
  • A circularly polarized microstrip patch antenna (MPA) using electromagnetic (EM) coupled fed method is analyzed in view of the two types of coupling mechanisms viz. cavity and parasitic type, proposed earlier. The patch-ground plane distance is varied in order to achieve the fore-mentioned types of couplings. For each case of patch-ground plane distance, the offset position of feedline is optimized for perfect matching and the boresight axial ratio (AR) is observed. It is seen that CP operation is possible only for cavity-type coupling (smaller patch-ground plane distances). The simulated results for the boresight AR for the two types of coupling mechanisms are presented.

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Analysis of the Molecular Mechanism of nlp Gene Involved in Transcriptional Regulation in Escherichia coli (대장균의 전사조절 유전자 nlp의 분자기구 해석)

  • 최용락;정수열;정정한;정영기
    • Microbiology and Biotechnology Letters
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    • v.21 no.3
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    • pp.229-238
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    • 1993
  • An nlp (Ner like protein) gene from E. coli was previously cloned and sequenced. Here we show that expression of the sugar metabolism related genes, lacZ, malQ and malP, increased 2.5-to 8.3-fold in the presence of a plasmid containing the nlp gene. This suggested that the nlp gene could induce maltose- and lactose-metabolism coordinately with crp*1 in the absence of cAMP. Using the nlp-lacZ fusion gene, it was possible to show the promoter of nlp was active in vivo.

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Designing a Microworld for Recursive Pasterns and Algebra (재귀적 패턴과 거북 마이크로월드 설계)

  • Kim Hwa-Kyung
    • The Mathematical Education
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    • v.45 no.2 s.113
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    • pp.165-176
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    • 2006
  • In this paper, we consider changes of algebra strands around the world. And we suggest needs of designing new computer environment where we make and manipulate geometric recursive patterns. For this purpose, we first consider relations among symbols, meanings and patterns. And we also consider Logo environment and characterize algebraic features. Then we introduce L-system which is considered as action letters and subgroup of turtle group. There are needs to be improved since there exists some ambiguity between sign and action. Based on needs of improving the previous L-system, we suggest new commands in JavaMAL microworld. So we design a microworld for recursive patterns and consider meanings of letters in new environments. Finally, we consider the method to integrate L-system and other existing microworlds, such as Logo and DGS. Specially, combining Logo and DGS, we consider the movement of such tiles and folding nets by L-system commands. And we discuss possible benefits in this environment.

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Computers and Mathematics Education (컴퓨터와 수학교육)

  • 조한혁
    • The Mathematical Education
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    • v.42 no.2
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    • pp.177-191
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    • 2003
  • In this paper, we present the theory of computers and mathematics education based on the concept of microworlds for mathematics education. We lust look back some previous papers published in the journal of the Korea society of mathematical education series A and else where. Then we present the new view points regarding mircroworlds and mathematics curriculems, microworlds and mathematics teaching and teaming, microworld based problem centered teaming, and microworld based diagnostics and debuggings. We use JavaMAL microworld that is designed to make LOGO and dynamic geometry system in one microworld to give some examples to explain the necessary mathematics educational needs fur designing microworlds for mathematics education. The JavaMAL microworld is a web based microworld that is programmed using JAVA, and the user on use script language, menus, keyboard, and mouse interaction to use the environment.

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Binding of Galectin-1 to Neutrophils Enhanced by Activation

  • Cho, Somi K.;Cho, Moonjae
    • Journal of Applied Biological Chemistry
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    • v.43 no.3
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    • pp.131-135
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    • 2000
  • Human polymorphonuclear neutrophils undergo diaphoresis after a selectin-mediated rolling on the endothelial cells of the blood vessel wall. Extravasation is believed to be an integrin-mediated process. Galectin-1 is a small dimeric beta-galactoside-binding protein synthesized by the endotherial cells and present in the perivascular connective tissue. In this study we suggest the possible role of galectin-1 in extravasation of the activated neutrophils. MAL lectin binding study showed, that f-MetLeuPhe-activated neutrophils decrease surface sialylation and increase galectin-1 binding via exposure of new galectin-1 binding sites. Desialylated HL-60 cells also show the same decrease in MAL binding and increase in galectin-1 binding, an increase which was not observed in the presence of lactose. Galectin-1 blotting analysis detected two possible major ligands (approximately 120 and 160 kDa) of galectin-1 from the desialylated HL-60 cell lysates.

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Automatic Adverb Error Correction in Korean Learners' EFL Writing

  • Kim, Jee-Eun
    • International Journal of Contents
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    • v.5 no.3
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    • pp.65-70
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    • 2009
  • This paper describes ongoing work on the correction of adverb errors committed by Korean learners studying English as a foreign language (EFL), using an automated English writing assessment system. Adverb errors are commonly found in learners 'writings, but handling those errors rarely draws an attention in natural language processing due to complicated characteristics of adverb. To correctly detect the errors, adverbs are classified according to their grammatical functions, meanings and positions within a sentence. Adverb errors are collected from learners' sentences, and classified into five categories adopting a traditional error analysis. The error classification in conjunction with the adverb categorization is implemented into a set of mal-rules which automatically identifies the errors. When an error is detected, the system corrects the error and suggests error specific feedback. The feedback includes the types of errors, a corrected string of the error and a brief description of the error. This attempt suggests how to improve adverb error correction method as well as to provide richer diagnostic feedback to the learners.