• 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.

• 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.

• Nuclear Engineering and Technology
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• v.14 no.1
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• pp.22-40
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• 1982

The nuclear LS-energy matrix elements have been calculated with the harmonic oscillator shell model wave functions for the configurations ( $l_{i}$ $l_{i+1}$｜ $l_{i}$ $l_{i+1}$) where 1$_1$= $l_{s}$ , $l_2$=lp, $l_3$=ld, 2s, $l_4$=1f, 2p, $l_{5}$ =1g, 2d, 3s. The resulting matrix elements are expressed in terms of both Talmi integrals $I_1$ and Slater integrals $F^{k}$ . In addition to this various sum rules are derived and applied to check the results of the calculations.ons.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.283-288
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• 2011

In this paper, an adaptive signal tracking loop for a GPS L1/L2C/L5 receiver is designed. The design parameters is adjusted according to the receiver's operating conditions such as the signal strength and the receiver dynamics by using the different characteristics of GPS L1, L2C and L5 signal. Simulation results show that the tracking accuracy of the proposed signal tracking loop is better than those of L1, L2C and L5 only signal tracking loop.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.2
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• pp.123-130
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• 1991

The mixed convection heat transfer from vertical inline plates has been studied numerically by the finite difference method and experimentally with Mach-Zehnder interferometer. The dimensionless spacing, $s/L_1$, the relative length, $L_2/L_1$ and the dimensionless temperature ratio, ${\Phi}_2/{\Phi}_1$ are varied parametically. The lower plate mean Nusselt numbers show same values as $s/L_1$, ${\Phi}_2/{\Phi}_1$ and $L_2/L_1$ increase. The upper plate mean Nusselt numbers increase as $s/L_1$ and ${\Phi}_2/{\Phi}_1$ increase, but $L_2/L_1$ decreases. The upper plate mean Nusselt number is higher than the lower plate mean Nusselt for $s/L_1$ 1.8 at Re=100, $Gr=10^4$, Pr=0.71, $L_2/L_1=0.5$ and ${\Phi}_2/{\Phi}_1=1.0$. A comparison between the experimental and numerical results show good agreement.

• Geophysics and Geophysical Exploration
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• v.10 no.2
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• pp.124-130
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• 2007

Least squares ($l^2$ norm) solutions of seismic inversion tend to be very sensitive to data points with large errors. The $l^1$ norm minimization gives more robust solutions, but usually with higher computational cost. Iteratively reweighted least squares (IRLS) method gives efficient approximate solutions of these $l^1$ norm problems. I propose an efficient implementation of the IRLS method for a hybrid $l^1/l^2$ minimization problem that behaves as $l^2$ norm fit for small residual and $l^1$ norm fit for large residuals. The proposed algorithm shows more robust characteristics to the decision of the threshold value than the l1 norm IRLS inversion does with respect to the threshold value to avoid singularity.

• Journal of Korean language education
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• v.29 no.1
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• pp.1-23
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• 2018

This paper investigates how adult Mandarin- and English- speaking learners of Korean perceive Korean vowels, with focus on the effect of the first language (L1) and the second language (L2) acoustic relationship, as well as the influence of Korean language experience. For this study, native Mandarin and Canadian English speakers who have learned Korean as a foreign language, as well as a control group of native Korean speakers, participated in two experiments. Experiment 1 was designed to examine acoustic similarities between Korean and English vowels, as well as Korean and Mandarin vowels to predict which Korean vowels are relatively easy, or difficult for L2 learners to perceive. The linear discriminant analysis (Klecka, 1980) based on their L1-L2 acoustic similarity predicted that L2 Mandarin learners would have perceptual difficulty rankings for Korean vowels as follows: (the easiest) /i, a, e/ >> /ɨ, ʌ, o, u/ (most difficult), whereas L2 English learners would have perceptual difficulty rankings for Korean vowels as follows: (the easiest) /i, a, e, ɨ, ʌ/ >> /o, u/ (most difficult). The goal of Experiment 2 was to test how accurately L2 Mandarin and English learners perceive Korean vowels /ɨ, ʌ, o, u/ which are considered to be difficult for L2 learners. The results of a mixed-effects logistic model revealed that English listeners showed higher identification accuracy for Korean vowels than Mandarin listeners, indicating that having a larger L1 vowel inventory than the L2 facilitates L2 vowel perception. However, both groups have the same ranking of Korean vowel perceptual difficulty: ɨ > ʌ > u > o. This finding indicates that adult learners of Korean can perceive the new vowel /ɨ/, which does not exist in their L1, more accurately than the vowel /o/, which is acoustically similar to vowels in their L1, suggesting that L2 learners are more likely to establish additional phonetic categories for new vowels. In terms of the influence of experience with L2, it was found that identification accuracy increases as Korean language experience rises. In other words, the more experienced English and Mandarin learners of Korean are, the more likely they are to have better identification accuracy in Korean vowels than less experienced learners of Korean. Moreover, there is no interaction between L1 background and L2 experience, showing that identification accuracy of Korean vowels is higher as Korean language experience increases regardless of their L1 background. Overall, these findings of the two experiments demonstrated that acoustic similarity between L1 and L2 sounds using the LDA model can partially predict perceptual difficulty in L2 acquisition, indicating that other factors such as perceptual similarity between L1 and L2, the merge of Korean /o/ and /u/ may also influence their Korean vowel perception.

• 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.

• Bulletin of the Korean Chemical Society
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• v.11 no.3
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• pp.206-208
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• 1990

Cu(II) hexaazamacrotricyclic complexes $[Cu(L)](ClO_4)_2$ and $[(Cu(L)Cl]ClO_4$, where L = 1,3,6,9,11,14-hexaazatricyclo$[12.2.1.1^{6,9}]octadecane(L_1)$ or 1,3,6,10,12,15-hexaazatricyclo$[13.3.1.1^{6,10}]eicosane(L_2)$, have been prepared by the simple template condensation reactions of triamines, diethylenetriamine for $L_1$, and N-(2-aminoethyl)-1,3-propanediamine for $L_2$, with formaldehyde in the presence of $Cu(OAc)_2\;or\;CuCl_2$. The Cu(II) complexes of $L_1$ contain two 1,3-diazacyclopentane ring moieties and those of $L_2$ contain two 1,3-diazacyclohexane ring moieties that are fused to the 14-membered macrocyclic framework. Spectra indicate that complexes $[Cu(L)](ClO_4)_2\;and\;[Cu(L)Cl]ClO_4$ have square-planar and square-pyramidal chromophores, respectively. square-planar $[Cu(L)](ClO_4)_2$ are remarkably stable against ligand dissociation in acidic aqueous solutions. Square-pyramidal $[Cu(L)Cl]ClO_4$ complexes dissociate their axial Cl-ligands easily in aqueous solutions to form $[Cu(L)H_2O]^{2+}$ species. Infrared and UV/vis absorption spectra of the Cu(II) complexes reveal that Cu-N interactions and the ligand field strengths are significantly weaker in the complexes of $L_2$ than in the complexes of $L_1$.