• Journal of the Korean Home Economics Association
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• v.18 no.4
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• pp.31-39
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• 1980

The basic pattern of skirt should be functional in addition to be fit the body. The author paid special attention to the expansion and contraction of the shell which were made the lower trunk and thigh caused by sitting motions. The replicas of the shell were taken by using a gypsum method on 1 female under 4 standardized motions; standing motion, (basic motion), sitting on the chair with flextion 90' at the hip and the knee joints sitting with dropping knees, and sitting with benting legs side wards. Those replicas obtained were developed to the patterns and changes in shape and area of those were measured. Typical displacement and transformation of the shell surface patterns were showed geographycally fig 5-1 to 5-4. mean values of expansion and constriction were obtained by measuring the shell surface on 60 female under the 4 motions. the mean values of it were showed numerically in Table 1-1 to 1-3. The following results were obtained; 1. Vertical constriction of front of the shell were observed near sulcus in guinalis, and vertical extension were near the knees. Horizontal extension were observed near the thighs and the knees. 2. Vertical constrictions of the back of the shell were observed near the knees. It seemed to be influnced the flexion angles of knee points. vertical extension were near gluteus and thighs. Horizontal constriction were small, and horizonlal extension were near gluteus. 3. The high rates of constriction and extension were found near sulcus in guinalis, glutes, and knees. 4. The rates of constriction and extension on the waist line were very low. 5. The highest values of constriction and extension were found in hip and knees.

• MALSORI
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• no.56
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• pp.103-125
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• 2005

We present a new method of measuring the volume and cross-sectional area of the vocal tract from magnetic resonance images. The vocal tract was divided by the 2 constriction points on the horizontal and vertical planes. The ratios of the volumes of the segment vocal tracts to that of the entire vocal tract play a crucial role in discriminating Korean monophthongs in that vowels were successfully discriminated by the ratios. The discriminant analysis also demonstrated that the acoustic parameters F1 and F2, in addition to the segment volumes, serve as significant parameters in discriminating Korean monophthongs.

• Speech Sciences
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• v.3
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• pp.83-92
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• 1998

Vowels are classified by vocal tract shapes. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as $F_l,\;F_2,\;F_3$, and so on. This study reviews the perturbation theory of the tract and determines the corresponding formant frequencies from modified vocal tracts using vocal tract area function. Then, formant variation is observed from the theory. Finally, each set of $F_l,\;F_2,\;and\;F_3$ frequency is input to a speech synthesis software to make a vowel sound. Auditory impression of each sound without any modification of its vocal tract shape is almost the same as the corresponding phonetic symbol. Formant frequencies of $F_l,\;F_2,\;F_3$ vary according to the perturbation theory. Generally, constriction along the node causes formant values to decrease while constriction along the anti-node cause it to increase. Vocal tracts modified by more than $3\;cm^2$ change vowel qualities of /a/ and /i/ into those of f /v/ and /$\varepsilon$/, respectively. This study will be helpful in simulating sounds from modified vocal tracts before any operation. Further studies are desirable to compare vocal tract shapes of various languages and their sounds together.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.175-184
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• 2023

Objective: To evaluate and compare a series of volume changes in the nasal cavity (NC), nasopharynx, oropharynx, and maxillary sinuses (MS) in growing Class III patients after either rapid palatal expansion (RPE) or alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy, by using cone-beam computed tomography (CBCT). Methods: Forty growing Class III patients were retrospectively selected and divided into two matched groups: RPE/FM (14 females, 6 males; mean age, 9.66 ± 1.23 years) and Alt-RAMEC/FM groups (14 females, 6 males; mean age, 10.28 ± 1.45 years). The anteroposterior and vertical displacements of Point A, the volumes of the NC, nasopharyngeal, oropharyngeal, and MS were measured at different time points: pretreatment (T1), postexpansion (T2), and postprotraction (T3). Results: Both groups demonstrated significant maxilla advancement (by 1.3 mm) during expansion, with a statistically significant intergroup difference during protraction (RPE/FM, 1.1 mm; Alt-RAMEC/FM, 2.4 mm; p < 0.05) and throughout the treatment (RPE/FM, 2.4 mm; Alt-RAMEC/FM, 3.7 mm; p < 0.05). NC and nasopharyngeal airway volumes increased significantly in both groups after expansion, protraction, and treatment. The oropharyngeal and MS volumes increased in both groups after protraction and post-treatment. However, no volumetric differences were observed between the two groups. Conclusions: There was no significant difference in airway volume changes, including NC, nasopharyngeal, oropharyngeal airway, and MS, between RPE/FM and Alt-RAMEC/FM groups at different time points. Although there was significantly more forward movement after protraction in the Alt-RAMEC/FM group, the difference was deemed too small to be clinically relevant.

• Speech Sciences
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• v.4 no.1
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• pp.19-34
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• 1998

The author collected and compared midsagittal, coronal, coronal oblique, and transversal images of Korean monophthongs /a, i, e, o, u, i, v/ produced by a healthy male speaker using 1.5 T MR, VISION. Area was measured by computer software after tracing the cross-section at different points along the tract. Results showed that the width of the oral and pharyngeal cavities varied compensatorily from each other on the midsagittal dimension. Formant frequency values estimated from the area functions of the seven vowels showed a strong correlation (r=0.978) with those analyzed from the spoken vowels. Moreover, almost all of 35 students who listened to the synthesized vowels from area data perceived the synthesized vowels as equivalent to the spoken ones. Movement of constriction points of vowel /u/ with wider lip opening sounded /i/ and led to slight changes in vowel quality. Jaw and tongue movement led to major volume variation with an anatomical limitation. Each comer vowel varied systematically from a somewhat constant volume of the average area. Thus, the author proposed that any simulation studies related to vocal tract area variation should reflect its constant volume. The results may be helpful to verify exact measurement of the vocal tract area through vowel synthesis and a simulation study before having any operation of the vocal tract.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.5
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• pp.1613-1623
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• 1996

In this paper, two discretization methods, hybrid and QUICK, are tested for the Navier-Stokes equations written in general nonorthogonal body fitted coordinates. Comparison is made by calculating two laminar flows at low Reynolds numbers of 10 - 100. One is a two-dimensional channel of gradually expanding cross section and the other is an axisymmetric flow through a circular tube having a circular constriction. Results show that the QUICK scheme results in a numerical solution more accurate than that of hybrid. The QUICK scheme also shows faster convergence for both test cases. As the number of grid points increases, all numerical solutions converge with more oscillation. The number of grid points in the y-direction(cross stream direction) is also shown to play a significant role in the approximation of convection term within separated flow zone.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.151-163
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• 2015

In this study, we aim to describe kinematic characteristics of Korean /l/-flapping in two speech rates (fast vs. comfortable). Production data was collected from seven native speakers of Seoul Korean (four females and three males) using electromagnetic midsagittal articulometry (EMMA), which provided two dimensional data on the x-y plane. We examined kinematic properties of the vertical/horizontal tongue tip gesture, the vertical/horizontal (rear) tongue body gesture, and the jaw gesture in an /i/-/i/ context. Gestural landmarks of the vertical tongue tip gesture are directly measured. This serves as the actual anchoring time points to which relevant measures of other trajectories referred. The study focuses on velocity profiles, closing/opening spatiotemporal properties, constriction duration, and constriction minima were analyzed. The results are summarized as follows. First, gradiently distributed spatiotemporal values of the vertical tongue tip gesture were on a continuum. This shows more of a reduction in fast speech rate, but no single instance of categorical reduction (deletion). Second, Korean /l/-flapping predominantly exhibited a backward sliding tongue tip movement, in 83% of production, which is apparently distinguished from forward sliding movement in English. Lastly, there was an indication of vocalic reduction in fast rate, truncating spatial displacement of the jaw and the tongue body, although we did not observe positional variations with speech rate. The present study shows that Korean /l/-flapping is characterized by mixed articulatory properties with respect to flapping sounds of other languages such as English and Xiangxiang Chinese. Korean /l/ flapping demonstrates a language-universal property, such as the gradient nature of its flapping sounds that is compatible with other languages. On the other hand, Korean /l/-flapping also shows a language-particular property, particularly distinguished from English, in that a backward gliding movement occurs during the tongue tip closing movement. Although, there was no vocalic reduction in V2 observed in terms of jaw and tongue body height, spatial displacement of these articulators still suggests truncation in fast speech rate.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.185-188
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• 2005

We presents a new method for the measurement and analysis of the volume of the vocal tract using 3D magnetic resonance image. The relative ratios of volume A, B, and C, which are divided by the 2constriction points formed on the horizontal and vertical plane in vocal tract, take a decisive role indiscriminating Korean monophthong. Together with Fl-F2 and the minimum cross sectional area in the vocal tract, the relative ratios of the regional volumes were proved to be significant parameter in statistic viewpoint.

• Speech Sciences
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• v.10 no.2
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• pp.145-157
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• 2003

Vowels are classified by the shapes of vocal tract. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as F1, F2, F3, and so on. The formant frequency is influenced by aperture and placement of tongue and the intensity is influenced by air pressure of subglottis. The object of this study compares to characterize the spectral outputs of oral and nasal spectra for the formant frequencies and intensity of Korean oral vowels. Subjects consisted of 20 normal persons (10 male and 10 female) without laryngeal pathology. The speech sample included /a/, /e/, /i/, /o/, /u/ of Korean oral vowels. The spectrum of each vowel was analysed by Nasal View and Real Analysis Program using Dr. Speech. The result showed that nasal intensity is decreased manifestly from F1 to F2. But oral intensity and Intensity is decreased little bit from F1 to F2. The most of values of nasal formant frequency is similarity oral formant frequency and Formant frequency or little bit smaller.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.1
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• pp.50-54
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• 1983

Contact resistance variation which may be called sliding noise in carbon film variable resistors whose resistance elements consists of linear resistivity distribution were measured with several kinds of sliders and were analyzed to reduce the contact resistance variation. About the measuring method, the standard method of measuring contact resistance variation specified by the variable Resistance Components Institute was adupted. By analyzing the experimental results, it has been shown that the primary cause of contact resistance variation is due to current constriction and small discharge sparks in the resistance film in the area close to the slide contact. Moreover, it has been found that the sliding noise would be reduced by increasing the number of contact points, sliding speed, and pressure, and by using some kinds of insulation oil on the contacting surface. High contact resistance variation is likely to occur in the area of high resistance variation in a logrithmic resistance taper.