• Title/Summary/Keyword: L2

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The Role of L1 and L2 in an L3-speaking Class

  • Kim, Sun-Young
    • Cross-Cultural Studies
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    • v.24
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    • pp.170-183
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    • 2011
  • This study explored how a Chinese college student who previously had not reached a threshold level of Korean proficiency used L1 (Chinese) and L2 (English) as a tool to socialize into Korean (L3) culture of learning over the course of study. From a perspective of language socialization, this study examined the cross-linguistic influence of L1 and L2 on the L3 acquisition process by tracing an approach to language learning and practices taken by the Chinese student as a case study. Data were collected through three methods; interview protocols, various types of written texts, and observations. The results showed that the student used English as a means to negotiate difficulties and expertise by empowering her L2 exposure during the classroom practices. Her ways of using L2 in oral practices could be characterized as the 'Inverse U-shape' pattern, under which she increased L2 exposure at the early stage of the study and shifted the intermediate language to L3 at the later stage of the study. When it comes to the language use in written practices, the sequence of "L2-L1-L3" use gradually changed to the "L2-L3" sequence over time, signifying the importance of interaction between L2 and L3. However, the use of her native language (L1) in a Korean-speaking classroom was limited to a certain aspect of literacy practices (i.e., vocabulary learning or translation). This study argues for L2 communication channel in cross-cultural classrooms as a key factor to determine sustainable learning growth.

Synthesis and Characterization of New Polyaza Non-macrocyclic and Macrocyclic Nickel(II) Complexes Containing One 1,3-Diazacyclohexane Ring

  • Lee, Yun-Taek;Jang, Bo Woo;Kang, Shin-Geol
    • Bulletin of the Korean Chemical Society
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    • v.34 no.7
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    • pp.2125-2130
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    • 2013
  • A new nickel(II) complex $[NiL^1]^{2+}$ ($L^1$ = 1-(2-aminoethyl)-3-(N-{2-aminoethyl}aminomethyl-1,3-diazacyclohexane) containing one 1,3-diazacyclohexane ring has been prepared selectively by the metal-template condensation of formaldehyde with N-(2-aminoethyl)-1,3-propanediamine and ethylenediamine at room temperature. The complex reacts with nitroethane and formaldehyde to yield the pentaaza macrocyclic complex $[NiL^2]^{2+}$ ($L^2$ = 8-methyl-8-nitro-1,3,6,10,13-pentaazabicyclo[13.3.1]heptadecane) bearing one C-$NO_2$ pendant arm. The reduction of $[NiL^2]^{2+}$ by using Zn/HCl produces $[NiL^3(H_2O)]^{2+}$ ($L^3$ = 8-amino-8-methyl-1,3,6,10,13-pentaazabicyclo[13.3.1]heptadecane) bearing one coordinated C-$NH_2$ pendant arm that is readily protonated in acid solutions. The hexaaza macrocyclic complex $[NiL^4]^{2+}$ ($L^4$ = 8-phenylmethyl-8-nitro-1,3,6,8,10,13-hexaazabicyclo[13.3.1]heptadecane) bearing one N-$CH_2C_6H_5$ pendant arm has also been prepared by the reaction of $[NiL^1]^{2+}$ with benzylamine and formaldehyde. The nickel(II) complexes of $L^1$, $L^2$, and $L^4$ have square-planar coordination geometry in the solid states and in nitromethane. However, they exist as equilibrium mixtures of the square-planar $[NiL]^{2+}$ (L = $L^1$, $L^2$, or $L^4$) and octahedral $[NiL(S)_2]^{2+}$ species in various coordinating solvents (S); the proportion of the octahedral species $[NiL(S)_2]^{2+}$ is strongly influenced by the ligand structure and the nature of the solvent. Synthesis, spectra, and chemical properties of the nickel(II) complexes of $L^1-L^4$ are described.

The Effects of L1 Rhetorical Styles on L2 Writing Quality

  • Kim, Sung-Hye
    • English Language & Literature Teaching
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    • v.11 no.3
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    • pp.39-56
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    • 2005
  • This study is a small-scale replication study of Kubota (1998). Kubota discovered that L1 rhetoric was not the main cause of L2 writing problems. The conclusion of Kubota's study was in contrast to that of contrastive rhetoric research that claimed that the use of L1 rhetorical styles in L2 writing negatively affects the quality of L2 writing, in particular, at the organizational level. According to Kubota(1998), the use of Japanese rhetorical styles did not deteriorate the quality of English writing. By investigating Korean ESL learners, this replication study examined whether L1 and L2 writings have the same rhetorical styles and how L1 rhetorical styles affect the L2 writing quality. The study analyzed Korean and English persuasive writings written by 12 Korean ESL learners in terms of organization. The results show that Korean learners of English used different rhetorical styles in their L1 Korean writing and L2 English writing. However, there was a positive relationship between L1 Korean and L2 English organization scores.

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Korean Secondary School Students' L2 Learning Motivation: Comparing L2 Motivational Self System with Socio-educational Model

  • Kim, Yoon-Kyoung;Kim, Tae-Young
    • English Language & Literature Teaching
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    • v.18 no.1
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    • pp.115-132
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    • 2012
  • In order to confirm ecological validity of D$\ddot{o}$rnyei's second language motivational self, the present study investigated 495 South Korean secondary school students' L2 learning motivation and motivated behavior by using a questionnaire survey. The participants' ideal L2 self, ought-to L2 self, integrativeness, and instrumentality were examined and compared to identify which motivational factor had the most effect on their motivated L2 learning behavior. Among Korean secondary school students, the concept of integrativeness was replaced with the ideal L2 self as a more appropriate concept for understanding Korean secondary school students' L2 learning motivation. As for instrumentality, promotional aspects demonstrated a significant correlation with both the ideal and ought-to L2 selves, whereas preventional aspects showed a relatively high correlation with the ought-to L2 self. The ideal L2 self had the most impact on the motivated behavior, and the ideal L2 self and ought-to L2 self reflected the students' different motivational characteristics. It is suggested that D$\ddot{o}$rnyei's (2005, 2009) L2 motivational self system can be a better psychological model than Gardner's (1985) socio-educational model for understanding Korean secondary school students' L2 learning motivation.

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Synthesis and Characterization of Ni(Ⅱ) Complexes with Aminophosphine, Ni(L)X$_2$ and [Ni(L)$_2$]Cl$_2$ (L = L$_1$, L$_2$ ; X = Cl$^-$, Br$^-$, I$^-$) (Aminophosphine류 리간드가 배위된 Ni(Ⅱ) 착물, Ni(L)X$_2$ 및 [Ni(L)$_2$]Cl$_2$ (L = L$_1$, L$_2$ ; X = Cl$^-$, Br$^-$, I$^-$)의 합성과 성질)

  • Jeong, Maeng Jun;Park, Sang Gyu;Jeong, Min Ho;Kim, Bong Gon;Do, Myeong Gi
    • Journal of the Korean Chemical Society
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    • v.38 no.4
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    • pp.288-294
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    • 1994
  • Several new nickel(II) complexes, [Ni(L)X$_2$ and [Ni(L)$_2$]Cl$_2$ (L = L$_1$, L$_2$ ; X = Cl$^-$, Br$^-$, I$^-$) have been synthesized by reacting NiX$_2$ or NiX$_2$, 6H$_2$O with aminophosphines(L) wherein L is 1,2-bis{(diphenylphosphino)amino}propane(L$_1$) or 1,2-bis{(diphenylphosphino)amino}ethane(L$_2$). These complexes are characterized by the optical spectroscopic methods (UV/Vis, CD, IR, $^1$H-NMR, and $^{31}$P-NMR) together with conductometer and elemental analysis. The complex with I$^-$ is tetrahedral, where the complexes with Cl$^-$ or Br$^-$ are square planar. The complexes, [Ni(L)X$_2$](X = Cl$^-$, Br$^-$) become tetrahedral, as they react with methyl iodide. The Ni(L)X$_2$ complexes underwent solvolysis with a various organic solvents such is EtOH, DMSO, THF and DMF.

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L-pre-separation axioms in (2, L)-topologies based on complete residuated lattice-valued logic

  • Zeyada, Fathei M.;Abd-Allahand, M. Azab;Mousa, A.K.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.2
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    • pp.115-127
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    • 2009
  • In the present paper we introduce and study L-pre-$T_0$-, L-pre-$T_1$-, L-pre-$T_2$ (L-pre-Hausdorff)-, L-pre-$T_3$ (L-pre-regularity)-, L-pre-$T_4$ (L-pre-normality)-, L-pre-strong-$T_3$-, L-pre-strong-$T_4$-, L-pre-$R_0$-, L-pre-$R_1$-separation axioms in (2, L)-topologies where L is a complete residuated lattice.Sometimes we need more conditions on L such as the completely distributive law or that the "$\bigwedge$" is distributive over arbitrary joins or the double negation law as we illustrate through this paper. As applications of our work the corresponding results(see[1,2]) are generalized and new consequences are obtained.

Effects of Nutritional Sources on Degradation of Polychlorinated Biphenyls (PCBs) by Pseudomonas sp. P2 (Pseudomonas sp. P2에 의한 Polychlorinated Biphenyls(PCBs) 분해에 대한 영양원의 영향)

  • 최상기;금정호
    • Journal of Environmental Science International
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    • v.5 no.5
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    • pp.611-617
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    • 1996
  • The effects of nutritional sources on growth of Pseudomonas sp. P2 were investigated in medium containing biphentyl as a carbon source. To determine characterization of Pseudomonas sp. P2, the incubation time was determined to 100 h of the log phase in the growth curve. The optimal compositions for the growth of Pseudomonas sp. P2 degrading polychlorinated biphenyls (PCBs) were 1000 mg/L $NH_4NO_3$, 1000mg/L KH_2PO_4$, 100mg/L MgSO_4$.$7H_2O$, 30mg/L $CaCl_2$.$2H_2O$, 200mg/L NaCl, and 10mg/L $FeSO_4$.$7H_2O$. Pseudomonas sp. P2 showed the degradability of 59.3%, 57.6%, 51.4%, and 48.7% at 500mg/L, 1000mg/L, 1500mg/L, and 2000mg/L of the PCBs within insulating oil after 100 h incubation under the optimum conditions, respectively.

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An Efficient Algorithm for mining frequent itemsets using L2-tree (L2-tree를 이용한 효율적인 빈발항목 집합 탐사)

  • 박인창;장중혁;이원석
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.259-261
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    • 2002
  • 데이터마이닝 분야에서 빈발항목집합 탐사에 관한 연구는 활발히 진행되어 왔지만 여전히 많은 메모리 공간과 시간을 필요로 한다. 특히 apriori 알고리즘에 기반한 방법들은 긴 패턴이 생성될수록 지수적으로 시간과 공간이 증가한다. 최근에 발표된 fp-growth는 일반적인 데이터 집합에서 우수한 성능을 보이나 희소 데이터 집합에서 효율적인 성능을 보여주지 못한다. 본 논문에서는 길이가 2인 빈발항목집합 L2에 기반한 L2-tree 구조를 제안한다. 또한 L2-tree에서 빈발항목집합을 탐사하는 L2-traverse 알고리즘을 제안한다. L2-tree는 L2를 기반으로 하기 때문에 L2가 상대적으로 적은 희소 데이터 집합 환경에서 적은 메모리 공간을 사용하게 된다. L2-traverse 알고리즘은 별도의 추출 데이터베이스를 생성하는 FP-growth와 달리 단순히 L2-tree를 오직 한번의 깊이 우선 탐사를 통해 빈발항목집합을 찾는다. 최적화 기법으로써 길이가 3인 빈발항목집합 L3가 되지 않는 L2 패턴들을 미리 제거하는 방법으로 C3-traverse 알고리즘을 제안하며 실험을 통해 기존 알고리즘과 비교 검증한다.

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Varietal Difference in Plant Regeneration from Cotyledon Culture of Capsicum annuum L. (고추 자엽에서 식물체 재분화의 품종간 차이)

  • 오명규;이영만;박문수
    • Korean Journal of Plant Tissue Culture
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    • v.25 no.5
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    • pp.301-304
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    • 1998
  • Effects of genotype and culture medium on plant regeneration from cotyledon segments of red pepper(Capsicum annuum L.) was investigated. Among combinations of IAA(0.25 and 0.50 mg/L) and zeatin(2.0 and 4.0 mg/L) added to MS medium, combination of 2.0 mg/L zeatin and 0.25 mg/L IAA was shown to be the best for shoot differentiation from cotyledon segments. Shoot regeneration from cotyledon explants took 9 to 25days, depending on genotypes and culture media. Early shooting was observed in Yeongyangjaelae, Putgochw, Karkovskij-A-35, Gris I-A-1 on MS medium containing 2.0 mg/L zeatin and 0.25 IAA mg/L. Percent of explants producing shoots, as also influenced by genotypes and culture media, were over 90% for 621, Yeongyangjaelae, Putgochw, Nikko jacksacgmulgochw, Ch-6-Num-216, and Kajenskij-A-35 when cultured on MS medum supplemented with 2.0 mg/L zeatin and 0.25 mg/L IAA and for Fresno chile, PI 169126, Kajenskij-A-35, jacksacgmulgochw, and PI 297438 on MS medium including 2.0 mg/L BA and 1.0 mg/L IAA.

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Effects of Planting Soil on the Soil Moisture and the Growth of Vitex rotundifolia for Green Roof (옥상녹화 식재지반이 토양수분과 순비기나무의 생육에 미치는 영향)

  • Park, Jun-Suk;Park, Je-Hea;Ju, Jin-Hee;Yoon, Yong-Han
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.98-106
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    • 2010
  • This study focuses on the appropriate planting soil for Vitex rotundifolia by planting soil. Different soil depth levels were achieved at 15cm and 25cm in the green roof module system that was created with woody materials for a $500{\times}500{\times}300mm$ area. The soil mixture ratio was $S_{10}$, $L_{10}$, $S_7L_3$, $S_5L_5$, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$. This study was carried out over five months between April and September, 2006. The amount of soil moisture tends to decrease according to the planting soil. For the experimental items $S_{10}$, $S_7L_3$ and $S_5L_5$, the amount of soil moisture tends to decrease rapidly. However, for the experimental items $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$, conditions containing perlite and peat moss, the amount of moisture tends to decrease more gradually. As a result, the use of soil-improving amending for the afforestation planting of roofs with a low level of management is need. After experimenting with the ratio of soil mixture for Vitex rotundifolia, the planting soil for experimental item $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ appeared excellent. For experimental item $S_{10}$, the growth of Vitex rotundifolia seemed to be weaker than that of others, because of the low levels of moisture and organic matter in the soil. For experimental item $L_{10}$, there appeared to be a low level of growth, even when the levels of moisture and organic matter were high. This may have occurred because of the low level of soil pH and the excessive amount of exchangeable cation. At the depth of 25cm, the growth of Vitex rotundifolia is vigorous overall. For experimental item at 15cm, Vitex rotundifolia was able to survive for 14 days without any rainfall and Vitex rotundifolia was better in amended soil, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$, than natural soil, SL.