• 대한기계학회논문집
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• 제12권2호
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• pp.295-307
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• 1988

본 연구의 목적은 흡기관내의 유체유동을 Lax-Wendroff 방법을 이용한 유한차분법으로 해석함으로서 엔진 흡기효율에 영향을 미치는 흡기관내 압력을 관찰하고 이를 이용한 흡기관계 최적 설계기술을 확립하고자 한다.

• 음성과학
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• 제9권3호
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• pp.143-153
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• 2002

This study was designed to determine (1) the effects of the following stop consonant on the vowel length in isolated bi-syllabic words, (2) the mechanism which renders vowels longer in duration before lax stops than tense stops, (3) where the aspiratory interval is included, in the vowel portion or the preceding consonantal portion and (4) the influence of the preceding consonants upon the duration of the following vowel. Measurements were made of five timing variables on acoustic signals as three native Korean speakers uttered isolated bi-syllabic /VCV/ words in which the vowel was identical, /$\alpha$/, and the C slot was filled with bilabial stops. Findings: (1) the vowel length before the lax stops was significantly longer than before the tense stops, while the difference in the vowel duration between the tense stops was insignificant or negligible, (2) the vowel length varied as a function of the articulatory force of the following consonants, regardless of the phonological unit of syllable, (3) The aspiratory interval is interpreted as a portion of the preceding consonant and (4) The effects of the preceding consonants on the final vowel length were not rule-governed.

• 음성과학
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• 제12권3호
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• pp.153-164
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• 2005

Two identical experiments are conducted at a six month interval in order to examine the VOT and its effect on the whole syllable duration or the rest portion of the syllable in Busan Korean. Just like the general characteristics of VOT, the aspirated stops consistently exhibit the longest VOT while tense stops have the shortest VOT. However, alveolar stops exhibit shorter VOT than labial stops, and it is contrary to the previous studies which claim that VOT values of labial stops are shorter than VOT values of alveolar stops. Moreover, there is a relationship between VOT and syllable/VC duration across stops. While VOT and syllable/VC duration have symmetric relationship for the aspirated velar and bilabial stops, other lax and tense stops exhibit the inverse relationship between the VOT and syllable/VC duration.

• 대한수학회지
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• 제42권6호
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• pp.1121-1136
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• 2005

Nonstandard finite difference schemes are considered for a generalization of the Cahn-Hilliard equation with Neumann boundary conditions and the Kuramoto-Sivashinsky equation with periodic boundary conditions, which are of the type $$U_t\;+\;\frac{{\partial}^2}{{\partial}x^2} g(u,\;U_x,\;U_{xx})\;=\;\frac{{\partial}^{\alpha}}{{\partial}x^{\alpha}}f(u,\;u_x),\;{\alpha}\;=\;0,\;1,\;2$$. Stability and error estimate of approximate solutions for the corresponding schemes are obtained using the extended Lax-Richtmyer equivalence theorem. Three examples are provided to apply the nonstandard finite difference schemes.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2011년도 춘계 종합학술대회 논문집
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• pp.319-320
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• 2011

Lax-Wendroff 기법을 기반의 천수방정식에 대한 유한요소 모형을 낙동강 상류부 단호교 지역에 적용하였다. 모형의 검증을 위하여 이동경계에 대한 Thacker (1981)의 정확해와 침수-노출 기법(wet-dry scheme)을 이용한 본 모형의 수치해를 비교하여 대체로 잘 일치함을 알게 되었다. 또한, U자형 만곡부를 포함한 수로의 흐름에 적용하여, 기존의 수리실험 결과, 수치모의 결과와 비교하고, 모형의 적용 가능성을 확인하였다. 낙동강 상류지역에 위치한 단호교 지역에 본 모형을 적용하고, 이를 기존 유한차분법에 의한 수치해와 비교하였다.

• 음성과학
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• 제4권1호
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• pp.135-145
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• 1998

An Electropalatographic (EPG) study was conducted to investigate the articulatory characteristics which determine the, distinction between the Korean lax fricative [s] and tense fricative [s']. This study also intended to test if an increase in the degree of tensity (lax fricative [s] < tense fricative [s']) induces a decrease in coarticulatory vocalic effects. The results indicated that the increase in the tensity of Korean fricatives is closely related to the increase in the narrowness of the groove width (wider contact at the place of articulation), the forward shifting in the place of articulation, and the longer duration of the constriction (longer maintenance in the manner of articulation). It was also found that coarticulatory vocalic effects on Korean fricatives are affected by Recasens' two rules of constraint (1983) : spatial and temporal constraints.

• 대한토목학회논문집
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• 제4권2호
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• pp.35-43
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• 1984

본 연구(硏究)의 목적(目的)은 개수로(開水路)의 수위(水位)의 변동(變動)에 따른 자유(自由) 지하수면(地下水面)과 개수로(開水路)에 작용(作用)하는 부정압력(不定壓力)의 분포(分布)를 계산(計算)할 수 있는 수치(數値) 모형(模型)을 개발(開發)하는데 있다. Diagnostic Eq.은 Point SOR 방법에 의해서, 그리고 Prognostic Eq.은 Implicit Lax-Wendroff 방법에 의하여 해석하였다. Simulation 조건들에서 지하수(地下水) 침투면(浸透面)의 변화를 예측(豫測)하기 위하여 투수성(透水性) 및 불투수성개수로(不透水性開水路)에 대하여 네가지 다른 경우에 대한 결과(結果)를 나타내었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.159-163
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• 2011

천수방정식에 대한 Lax-Wendroff 기법을 기반으로 한 유한요소 모형을 낙동강 상류부 단호교 지역에 적용하였다. 모형의 검증을 위하여 이동경계에 대한 Thacker (1981)의 정확해와 젖음-마름 기법(wet-dry scheme)을 이용한 본 모형의 수치해를 비교하여 대체로 잘 일치함을 알게 되었다. 또한, U자형 만곡부를 포함한 수로의 흐름에 적용하여, 기존의 수리실험 결과, 수치모의 결과와 비교하고, 모형의 적용 가능성을 확인하였다. 낙동강 상류지역에 위치한 단호교지역에 본 모형을 적용하고, 이를 기존 유한차분법에 의한 수치해와 비교하였다.

• Nonlinear Functional Analysis and Applications
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• 제27권3호
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• pp.679-689
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• 2022

In this paper, we establish sufficient conditions for the existence and uniqueness of solution for a class of initial boundary value problems with Dirichlet condition in regard to a category of fractional-order partial differential equations. The results are established by a method based on the theorem of Lax Milligram.

• 말소리와 음성과학
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• 제14권1호
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• pp.13-19
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• 2022

This study analyzed the pronunciations of Japanese fricative /s/ and affricate /ts/ by 24 Japanese and 40 Korean speakers using the rise and steady+decay durations of their frication part in order to clarify the characteristics of their pronunciations. Discriminant analysis revealed that Japanese speakers' /s/ and /ts/ were well classified by the acoustic boundaries defined by a discriminant function. Using this boundary, Korean speakers' production of /s/ and /ts/ was analyzed. It was found that, in Korean speakers' pronunciation, misclassification of /s/ as /ts/ was more frequent than that of /ts/ as /s/, indicating that both the /s/ and /ts/ distributions shift toward short rise and steady+decay durations. Moreover, their distributions were very similar to those of Korean fricatives and affricates. These results suggest that Korean speakers' classification error might be because of their use of Korean lax and tense fricatives to pronounce Japanese /s/, and Korean lax and tense affricates to pronounce Japanese /ts/.