• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.2
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• pp.98-102
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• 2006

Background and Objectives : Voice onset time(VOT) is defined as the time interval from oral release of a stop consonant to the onset of glottal pulsing in the following vowel. VOT is a temporal characteristics of stop consonants that reflects the complex timing of glottal articulation relative to supraglottal articulation. Stop consonants are characterized by creation of a pressure difference across a complete occlusion in the vocal tract, followed by a sudden release 'burst' due to opening that occlusion. The objects of this study is to evaluate a usefulness of voice onset time in the assessment of voice disorderd patients. Subjects : Subjects were 20 adults with normal voice and with benign laryngeal disorders. Subjects with voice disorders represented the following vocal pathologies : vocal polyp, vocal nodule, Reinke's edema and unilateral vocal fold paralysis(UVFP). Control subjects were matched for age (21-40 yews old) and sex(male) with the voice disorders subjects and had normal vocal qualities with no history of voice disorders. Methods : Each voice-disordered and matched control subject read the test passages containing three types of Korean bilabial consonants. VOT measures were made for the initial $/p/p^h/\;and\;/p'/$. VOT was measured using acoustic waveform or wide band spectrogram. Results : For each voiceless stop consonants, there was a significant difference in VOT between the voice disordered and normal subjects. The mean VOTs of the lax stops in UVFP was significantly shorter than those of control subjects in the UVFP. The mean VOTs of the aspirated stops in the vocal polyp and nodule were longer than those of control subjects, but not significant. The mean VOTs of the glottalized in voice disordered groups were longer than those of control subjects, and significant statistically in the UVFP. Conclusions : VOT may be a clinically useful acoustic parameter in the assessment of voice disordered patients, especially in the unilateral vocal fold paralysis.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.139-141
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• 2006

Korean college students' experience in studying English overseas playes the significant role to their perception, not production. Korean Group which experiences foreign-stay for almost 1 year shows the similar pattern with its counterpart, Korean Non- Experiencing Group, in producing the signal of pre-vowel. On the contrary, Korean Experiencing Group shows the similar perceptual pattern with Native Speakers in word-final non-release stops.

• MALSORI
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• no.38
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• pp.41-70
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• 1999

Researches on perception have, in recent years, been increasingly popular as a means of accounting for cross-linguistic sound patterns (Ohala, 1992; Hemming, 1995; Jun, 1995; Steriade, 1997 among others). In loanword phonology, Silverman(1990, 1992) argues that words from a source language are scanned through the perceptual level and that the features perceived by a speaker are stored in the input to be processed according to his/her native language's phonological constraints. The purpose of this paper is to test the validity of Silverman's proposal by examining the correlation between perception and production of Korean learners of English. We specifically focussed on perception and production of stop release by contrasting English loanwords with English words loarned through education to see if there were any significant differences. The results showed that there was no substantive correlation between the Korean speakers' perception of the loanwords pronounced by English speakers and their own production of those words. In the case of English words, however, the Korean speakers' production was closely related with their perception, although some inter-speaker variations were observed. With Optimality Theory (Prince & Smolenksy, 1993) as a theoretical framework of analysis, it was shown that the theory is a useful means of implementing a phonetics-phonology interface and relating perceptual processes with speech production. Specifically, under the assumption that loanwords with [t]~[t/sup h/] alternation (e.g.,'cut') are originally borrowed into Korean as two different input forms, all the alternations could be straightforwardly accounted for in terms of a unified ranking of constraints.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.53-67
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• 2005

It is known that Korean stop consonants in syllable-initial position are of three types : lax, aspirated and forced (or unaspirated). In syllable-final position, however, these three different types are merged to a single type with the same place of articulation, although the original three-way distinction is preserved in Korean orthographic (Hangul) system. Thus the syllable-final stops are phonetically realized as voiceless "applosives" which are characterized by the absence of oral release. The aim of the present study is to investigate the laryngeal adjustments for these syllable-final stops in various phonological conditions by using fiberscope, and, is to further investigate electromyographically the laryngeal adjustments for Korean stops both in the syllable-initial and final positions in various phonological conditions. The results can be summarized as follows : 1. In the case of syllable-initial stops, the glottal widths in each three types of the Korean stops during the articulatory closure are clearly different. And the pattern of thyroarytenoid(VOC) activity appeared to characterize the three different types of Korean stops. 2. The basic laryngeal feature of the Korean syllable-final applosives is characterized by a small degree of glottal opening which begins at or slightly after the oral closure. 3. In the case, syllable-final stop followed by the copula "ita", the syllable- final stop is pronounced as the stop consonant at the initial position of the following syllable containing the vowel[i], the underlying features of three-way distinction for the stops in the Korean orthographic(Hangul) system being manifested at the laryngeal adjustment. 4. In the case of the final applosives followed by the initial stops and fricatives, the laryngeal feature of the final applosives appears to be assimilated by that of the following consonant irrespective of the difference in the place of articulation, as far as the glottal abduction/adduction is concerned. It is clearly demonstrated in the case of syllable-initial stop that thyoarytenoid(VOC) activity is suppressed for the production of the stop consonants in question, the degree of which is slightest for the forced type and most marked for the aspirated type, while it is moderate for the lax type.

• Korean Journal of Health Education and Promotion
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• v.25 no.3
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• pp.111-124
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• 2008

Objectives: The purpose of this study was to suggest effective methods for not only preventing college students from being exposed to smoking but also helping them stop smoking, by examining and analysing a variety of factors related to their smoking behavior. Methods: To accomplish the purpose, this study was carried out using 1,553 valid questionnaires selected from 1,584 questionnaires completed and returned by 1,800 randomly chosen students of 2 colleges and 3 universities in Gyeongsangbuk-do Province and Daegu City during the period of April 3 through April 21, 2006. Results: It was turned out that while the total smoking rate of whole students was 52.4% in male students and 9.1% in female students, the smoking rate after their admission to the college was 27.1% in males and 1.5% in females. It was also shown that both the perceived susceptibility and barrier factors of Health Belief Model were statistically significant, and that the perceived seriousness factors were entirely significant in all other variables except the body seriousness. The perceived benefit factors were significant in only the variable that there would not be any improvement in academic performance even after stopping smoking. A relation between smoking and stop smoking program or smoking prevention program showed that the non-smoking rate was significantly high among the college students who participated in such programs while in middle school. When variables having a significant effect on smoking students after their admission were analysed, it was shown that the smoking rate was higher among males than females students, and that the more the number of smoking friends is and the more the number of students thinking that stop smoking would make it difficult to release stress and make friends is, the higher the smoking rate is among students. It is required, therefore, to encourage students to continuously participate in more smoking prevention programs from middle school, and to put an emphasis on a variety of smoking-related illnesses and advantages from non-smoking. Conclusions: Since the current smoking rate among college students is relatively high but most of the smoking students surveyed are ready to actually try to stop smoking, it will be possible to significantly reduce the smoking rate among college students if proper methods are suggested to eliminate barrier factors they face while participating in the stop smoking programs.

• Journal of Acupuncture Research
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• v.22 no.2
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• pp.191-201
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• 2005

Background & Objective: Articular cartilage is a potential target for drugs designed to inhibit the activity of matrix metalloproteinases (MMPs) to stop or slow the destruction of the proteoglycan and collagen in the cartilage extracellular matrix. The purpose of this study was to investigate the effects of Aralia cordata Thunb. in inhibiting the release of glycosaminoglycan (GAG), the degradation of collagen, and MMP activity in rabbit articular cartilage explants. Methods : The cartilage-protective effects of Aralia cordata Thunb. were evaluated by using glycosaminoglycan degradation assay, collagen degradation assay, colorimetric analysis of MMP activity, measurement of lactate dehydrogenase activity and histological analysis in rabbit cartilage explants culture. Results : Interleukin-la (IL-1a) rapidly induced GAG, but collagen was much less readily released from cartilage explants. Aralia cordata Thunb. significantly inhibited GAG and collagen release in a concentration-dependent manner. Aralia cordata Thunb. dose-dependently inhibited MMP-3 and MMP-13 expression and activities from IL-1a-treated cartilage explants cultures when tested at concentrations ranging from 0.02 to 0.2 mg/ml. Aralia cordata Thunb. had no harmful effect on chondrocytes viability or cartilage morphology in cartilage explants. Histological analysis indicated that Aralia cordata Thunb. reduced the degradation of the cartilage matrix compared with that of IL -1a-treated cartilage explants.

• Maritime Security
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• v.2 no.1
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• pp.125-149
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• 2021

Even 10 years after the Fukushima nuclear disaster, Japan has yet to solve the problems emerging from generating contaminated water every day. Japan has unilaterally decided to release nuclear wastewater in the sea despite Korea's concerns about safety as their radioactive water storage tanks reach the limits. Despite Korea's response, Japan is still preparing to discharge nuclear wastewater without fulfilling its obligations under the United Nations Convention on the Law of the Sea. There are concerns about marine pollution caused by the radioactive materials from nuclear wastewater and invading Korea's maritime sovereignty. In particular, it is impossible to reverse the effects of environmental pollution, so plans to discharge radioactive water must be prevented unless immediate safety is guaranteed. This study proposes Korea's response strategy to resolve the conflict between the two countries due to plans to release contaminated water. Korea should respond to Japan's release of nuclear wastewater in the sea in various ways through cooperation with Japan, provisional measures, and cooperation with neighboring countries.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.63-70
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• 2009

A steam generator tube rupture (SGTR) accident, which is a partial reactor building bypass scenario, has a low probability and high consequences. SAMG has been used to manage the progression of severe accidents and the release of fission products induced by an SGTR at the Wolsong plants. Four of the six SAGs in the SAMG are used to manage the progression of a severe accident induced by an SGTR at the Wolsong plants. The results of the ISAAC code calculation have shown that the proper use the SAMG can stop a severe accident from progressing and keep the reactor building intact during a severe accident. These results confirm that the SAMG is an effective means of managing the progression of severe accidents initiated by an SGTR at the Wolsong plants.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1252-1257
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• 2003

This paper present a procedure of meter-out flow control method for dump valve in full-scale airframe test. Emergency stop, which results in dump state, can be happened during full-scale airframe test by several causes. Because servo valve can't control hydraulics actuator in the dump state, pressure in cylinder chamber may rise abruptly and overload can be acted to the test article. In this paper, the procedure and technology of orifice setting are investigated to protect the test article from unexpected loads by dump. The test results show that the presented methods decrease peak loads and improve unloading characteristics of hydraulic actuators in the dump state.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.45-53
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• 2008

The burning behaviors of board for flooring materials were investigated using cone calorimetry at an incident heat flux of $50kWm^{-2}$. Seven domestic flooring materials were used to observe the burning behavior of maximum heat release rate, total heat release and average heat release rate. The experimental data indicated that the medium density fiberboard (MDF) flooring had higher release rate than the other flooring materials. Also, the mass loss of MDF flooring was higher than the other floors. When measuring the smoke production from burning, PE fiberboard flooring and PVC Plastic Resin Sheet showed higher carbon monoxide and carbon dioxide yield than the others. The average smoke release of both carbon dioxide and carbon monoxide through specific extinction area was similar. Toxic smoke measurement from flooring materials were determined by the mouse stop motion, and the results indicated that MDF flooring contains more toxic material than the other flooring materials.