• 한국광학회지
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• 제17권5호
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• pp.447-454
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• 2006

Brewster 각으로 양면이 가공된 $Cr^{4+}$ : YAG 결정이 장치된 Z자형 공진기의 안정영역에 대하여 열 렌즈 효과를 고려하지 않았을 때와, 고려하였을 때의 경계값의 해석적 해를 구하였다. 또한 수차 변환 행렬들을 사용하여 공진기의 안정성, 빔 허리, 그리고 비점수차 보상에 대한 열 렌즈 효과가 미치는 영향도 알아보았다. 결정이 오목거울 사이의 중간 위치에 놓이고, 오목거울과 반사거울 및 출력거울의 거리가 같을 때에는 공진기의 안정영역에 미치는 열 렌즈 효과의 영향은 적으나, 빔 허리는 반사거울에서 구결면보다 자오면에서의 영향이 더 크므로 열 렌즈 효과가 있을 때의 비점수차 보상은 더 어려워진다. 이러한 결과는 Kerr 렌즈 모드 잠금에서도 열 렌즈 효과가 고려되어야 함을 보인다.

• 음성과학
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• 제9권3호
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• pp.223-235
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• 2002

Unlike Seoul dialect, in the Busan dialect, /ㅅ/ and /ㅆ/ are phonemically non-distinctive and realization of tensing is non-productive, on the other hand, that of voicing is productive. In order to discover causes of such characteristics in Busan dialect, this paper firstly compared acoustic characteristics of Seoul dialect with those of Busan dialect on fricative /ㅅ/ and /ㅆ/. The result showed that Busan dialect has much shorter length of friction and aspiration intervals of word initial and word-medial position than Seoul dialect. I expect that these results are important keys to discover causes of the following characteristics of Busan-dialect - non-distinction, non-productivity of tensing, and productivity of voicing - on Fricative /ㅅ/ and /ㅆ/.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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• pp.117-122
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• 1996

This paper proposes a derivational account of tensing and neutralization of obstruents in Korean within the theory of Government Phonology (GP) (Kaye, Lowenstamm and Vergnaud 1990, henceforth KLV; Park 1996). We begin by outling the relevant tensing and neutralization data in Korean. We point out several problems that need to be addressed in any account of these data. We then set out the central notions of GP, pointing out how adherence to the requirement that government relations remain constant throughout a derivation under the Projection Principle prevents a GP account of tensing and neutralization in Korean, which requires government relations to switch between lexical and phonetic representations. To address this problem, we propose abandoning the Projection Principle, extending lexical representations in GP along the lines of the Markedness Theory approach (Michaels 1989), and adopting the economy principles for derivation of the Minimalist approach (Chomsky 1993; Chomsky & Lasnik 1991). finally, we summarize the analysis of obstruent phenomena in Korean within GP extended in these ways.

• 말소리와 음성과학
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• 제3권2호
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• pp.29-35
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• 2011

This paper examines several articulatory properties of /k/, known as a trigger of place assimilation as well as the object of post-obstruent tensing (/tk/), in comparison to non-assimilating controls (/kk/ and /kt/). Using EMMA, tongue body articulation in the place assimilation context robustly shows greater spatio-temporal articulation and lower jaw position. Results showed several characteristics. Firstly, constriction duration of the tongue body gesture in C2 of the assimilation context (/tk/) was longer than non-assimilating controls (/kk/ and /kt/). Secondly, constriction maxima also demonstrated greater constriction in the /tk/ sequences than in the control /kk/, but similar values with the control /kt/. In particular, results showed a significant relationship between the two variables - the longer the constriction duration, the greater the constriction degree. Lastly, jaw height was lower for the assimilating context /tk/, intermediate for the control /kk/, and higher for the control /kt/. Results suggest that speakers have lexical knowledge of place assimilation, producing a greater tongue body gesture in the spatio-temporal domains with lower jaw height as an indication of anticipating reduction of C1 in /tk/ sequences.

• 한국광학회지
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• 제17권5호
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• pp.455-460
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• 2006

광섬유 연결 반도체레이저를 여기원으로 하는 단면여기 세라믹 Nd:YAG 레이저의 출력 특성과 레이저 출력에 영향을 미치는 열 영향에 대하여 연구하였다. 반사율이 90.4 %인 출력거울을 사용하였을 경우 약 33.8 %의 최대 출력 효율을 얻었고, 기울기 효율은 39.3 %를 나타내었다. 세라믹 Nd:YAG의 열렌즈 효과에 의해 여기 파워 6 W 이상에서 출력 감소 현상이 나타났으며, 12 W 부근에서 레이저가 발진되지 않았다.

• 천문학회보
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• 제25권2호
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• pp.104-104
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• 2000

• 말소리와 음성과학
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• 제12권3호
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• pp.15-23
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• 2020

This study examines the duration of Korean lax and tense stops in the prosodic word-medial position, their interactions with nearby segments, and the phonological implications of these interactions. It first examines the lengthening of consonants at the function of the short lax stop. Experiment 1 shows that the sonorant C1 is significantly longer before a short lax stop C2 than before a long tense stop. Experiment 2 shows that the short lax stop C1 cancels the contrast between the lax and tense obstruent at C2, making them appear as long tense obstruents (Post-Stop Tensing Rule). We suggest that such lengthening phenomena occur in Korean to robustly preserve the contrastive length difference between C and CC. Second, this study examines the vowel shortening, known as Closed-Syllable Vowel Shortening, before a long tense stop or before the consonant sequence. Experiment 3 suggests that it be interpreted as temporal adjustment to make the interval from the onset of a vowel to the onset of the following vowel of near-equal length. Conclusively, we suggest that Korean speech be planned and controlled with two specific intervals. One is the duration of contrastive consonant intervals between vowels, and the other is the duration from the onset of a vowel to the onset of the following vowel.

• 한국광학회지
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• 제18권3호
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• pp.208-215
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• 2007

광섬유 연결 반도체레이저 여기 세라믹 Nd:YAG 레이저의 열렌즈를 보상하기 위한 공진기를 구성하였다. 초점거리 30 mm, 유효직경 22 mm인 보상렌즈를 레이저 매질의 단면으로부터 25 mm 떨어진 곳에 위치시켜 열렌즈 효과를 보상하였다. 보상렌즈가 없는 경우 레이저 출력은 열렌즈 효과에 의해 여기파워 6 W 이상에서 급격히 감소하기 시작하였으며, 12 W에 이르러서는 레이저가 거의 발진되지 않았다. 열렌즈 효과가 보상되었을 경우 레이저 출력은 선형적으로 증가하였으며, 여기파워 12 W에서 $M^{2}$값은 2.4로 좋은 빔질을 나타내었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.1092-1095
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• 2000

Computer graphics(CG) is one of the most useful tools by which we can easily understand visible/invisible natural phenomena. Namely, phenomena in the universe is attractive one because of its beauty and invisibility on the earth. For gravitational tensing phenomena, a ray tracing algorithm is proposed based on a lens-plane. In the method, position of gravitational sources is restricted. In this paper an improved visualization method is proposed, which can represent more complex situation than the previous method.

• 한국영어학회지:영어학
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• 제1권1호
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• pp.19-38
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• 2001

The question of how / ... VCV .../ sequences should be syllabified is a much discussed, yet unresolved, issue in English phonology. While most researchers recognize an over-all universal tendency towards open syllables, there seem to be at least two different views as regards the analysis of / ... VCV .../ when the second vowel is unstressed: ambisyllabicity (e.g., Kahn 1976) and resyllabification (e.g., Borowsky 1986). Basically, we adopt the latter view and will present further evidence in its favor. This does not exclude low-level “phonetic” ambisyllabification, however. Following Nespor and Vogel (1986), we also assume that the domain of syllabification or resyllabification is the phonological word. With the new conception of the syllable structure of English, we attempt a reanalysis of Aitkin's Law as well as fe-tensing in New York City and Philadelphia.