• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.447-454
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• 2006

We obtained analytic solutions of boundary conditions to the stable region of Z-fold $Cr^{4+}$ : YAG laser cavity when the conditions are with and without thermal tensing effect. Also we investigated the influence of the thermal tensing effect on the stability of cavity, beam waist, and astigmatic compensation using aberration transformation matrices. The thermal tensing effect almost has no influence on the stable region of the cavity when the crystal is located in the middle of two concave mirrors and when the distances from the concave mirror to the reflecting mirror and the output coupler are the same. The beam waist, however, is affected more in a tangential plane than in a sagittal plane, and so it is difficult to have astigmatic compensation when the thermal tensing effect exists. This result means that the thermal tensing effect should be considered even for the Kerr-lens mode-locking.

• Speech Sciences
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• v.9 no.3
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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/.

• Proceedings of the KSPS conference
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• 1996.10a
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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.

• Phonetics and Speech Sciences
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• v.3 no.2
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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.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.455-460
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• 2006

The output characteristics of a ceramic Nd:YAC laser pumped by a fiber-coupled laser diode was investigated. An efficiency and a slope efficiency of 33.8 % and 39.3 % respectively were obtained, under an output coupler reflectance of 90.4 %. The laser power has decreased suddenly due to the thermal tensing effect more than 6 W pumping powers.

• The Bulletin of The Korean Astronomical Society
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• v.25 no.2
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• pp.104-104
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• 2000

• Phonetics and Speech Sciences
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• v.12 no.3
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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.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.208-215
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• 2007

A fiber-coupled laser-diode pumped ceramic Nd:YAG laser for compensating the thermal tensing effect was developed. The thermal tensing effect was compensated using a convex lens, which was 25 mm away from the laser rod, with a focal length of 30 mm and an effective clear aperture of 22 mm. Without a compensator, the laser output power decreased suddenly above a pump power of 6 W. Using a compensator, the laser output power increased linearly according to the pump power. The beam propagation factor $M^{2}$ was 2.4 under a pump power of 12 W.

• Proceedings of the IEEK Conference
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• 2000.07b
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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.

• Korean Journal of English Language and Linguistics
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• v.1 no.1
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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.