• Communications of the Korean Mathematical Society
• /
• v.27 no.2
• /
• pp.377-384
• /
• 2012

In this paper some properties of sequentially closed sets and $k$-closed sets in a topological space are discussed, it is shown that a space is a $k$-quotient image of a metric space if and only if its each sequentially closed set is $k$-closed, and some related examples about connectedness are obtained.

• Phonetics and Speech Sciences
• /
• v.2 no.4
• /
• pp.223-228
• /
• 2010

This study investigated the closed quotient and other voice quality parameters using electroglottography (EGG) in sustaining the vowel /a/ and reading a sentence at the comfortable pitch and loudness in healthy Korean adults. Seventy two healthy adults (36 men, 36 women) aged 20~40 years were included in the study. The tasks were recorded and analyzed using Lx Speech Studio. In vowel sustaining task, closed quotient (Qx), fundamental frequency (Fx), sound pressure level (SPL), Jitter, and Shimmer were measured. In sentence reading task, closed quotient (DQx), fundamental frequency (DFx), and sound pressure level (DAx) were measured. The sex effects were observed on Qx, Fx, Shimmer, DQx, and DFx. Men had significantly higher Qx and DQx than women, but had significantly lower Shimmer than women. However, there was no sex effect on Jitter. The task effects on Qx and SPL as well as DQx and DAx were also assessed. Qx and SPL were significantly higher than DQx and DAx in both gender. This study showed that the closed quotients in both vowel sustaining and sentence reading tasks were significantly related to other voice quality parameters. Therefore, clinicians and researchers should describe the voice quality parameters like fundamental frequency, sound pressure level, Jitter, Shimmer, and so on when reporting closed quotients using EGG.

• Journal of applied mathematics & informatics
• /
• v.10 no.1_2
• /
• pp.51-62
• /
• 2002

The present paper gives a new construction of a quotient BCI(BCK)-algebra X/${\mu}$ by a fuzzy ideal ${\mu}$ in X and establishes the Fuzzy Homomorphism Fundamental Theorem. We show that if ${\mu}$ is a fuzzy ideal (closed fuzzy ideal) of X, then X/${\mu}$ is a commutative (resp. positive implicative, implicative) BCK(BCI)-algebra if and only if It is a fuzzy commutative (resp. positive implicative, implicative) ideal of X Moreover we prove that a fuzzy ideal of a BCI-algebra is closed if and only if it is a fuzzy subalgebra of X We show that if the period of every element in a BCI-algebra X is finite, then any fuzzy ideal of X is closed. Especiatly, in a well (resp. finite, associative, quasi-associative, simple) BCI-algebra, any fuzzy ideal must be closed.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.5
• /
• pp.437-446
• /
• 2008

Electroglottography (EGG) is a simple and non-invasive technique for analyzing the vibratory patterns of the vocal folds by detecting impedance changes across the larynx. An abnormal electroglottogram is shown in patients who have a dysphagia associated with neuromuscular disorder. Electroglottography offers reliable informations for diagnosis of swallowing disorder and gives quantitative datas. The purpose of this study is to provide the normal value of electroglottography in normal adults. We took electroglottograms of 80 adults who have no problem in swallowing and utterance. EGG data were analyzed to find out the value of Pitch, Jitter and Closed quotient with a commercially available software. There were significant differences between a usual voice and loud voice in 3 measures on the EGG signalmean pitch, Avg. jitter, mean quotient. To get a proper electroglottography, phonation of a usual voice was better than a loud voice. Four measurements- S.D pitch, Avg. Jitter, Mean closed quotient, S.D closed quotient- were independent of sex for adult. Three measurements- Mean pitch, S.D pitch, Mean closed quotient - were independent of age for adult aged twenties to fifties. The Avg. Jitter of twenties appeared to be lower than those of forties and fifties. The S.D closed quotient of twenties appeared to be lower than those of thirties, forties and fifties.

• Speech Sciences
• /
• v.15 no.4
• /
• pp.147-157
• /
• 2008

Habitual speaking fundamental frequency (sF0) plays an important role in determining the voice classification, which can be presented differently depending on the vocal fold length and language habits. The purpose of this study, therefore, was to compare the differences in sF0 for voice classification and closed quotient between speaking and singing. Seventeen singers (7 sopranos, 5 tenors, 5 baritones, mean age 25.1 years) with no evidence of vocal folds pathology were participated. sF0 and closed quotient (CQ) both in speaking and in singing (A3-A5 with soprano, A2-A4 with tenor and baritone) were measured using SPEAD program and electroglottography. No significant differences were observed for sF0 between tenor and baritone groups (p> 0.05). However, CQ in singing was significantly different among three groups (p< 0.05), but CQ in speaking was not (p> 0.05). Furthermore, CQ was significantly different with both soprano (p< 0.01) and tenor groups ((P= 0.02) whereas baritone group revealed there is no difference when compared between speaking and singing. No significant differences in sF0 between tenor and baritone participants may result from decision-making for voice classification by experience and should measure sF0 before determining the voice classification.

• Journal of the Korean Mathematical Society
• /
• v.46 no.4
• /
• pp.859-893
• /
• 2009

In this article, we will characterize structures of geometric quotient orbifolds of G-manifold of genus two where G is a finite group of orientation preserving diffeomorphisms using the idea of handlebody orbifolds. By using the characterization, we will deduce the candidates of possible non-hyperbolic geometric quotient orbifolds case by case using W. Dunbar's work. In addition, if the G-manifold is compact, closed and the quotient orbifold's geometry is hyperbolic then we can show that the fundamental group of the quotient orbifold cannot be in the class D.

• Phonetics and Speech Sciences
• /
• v.2 no.4
• /
• pp.11-18
• /
• 2010

This study compared classical operatic singing and applied music singing using the vocal assessment software, Dr. Speech and SPEAD from Lx Speech Studio. Participants in this study included: eight female operatic singers (mean 22.6 yrs, average career 7.5 yrs); eight male operatic singers (mean 25.6 yrs, average career 7.3 yrs); eight female applied music singers (mean 25.1 yrs, average career 6.1 yrs); and eight male applied music singers (mean 27.6 yrs, average career 6.8 yrs). The results demonstrated significantly higher closed quotient values in female applied music singers during singing (p<.05). In addition, higher closed quotient values in speaking were presented in male classical singers and longer MPT was obtained in female operatic singers (p<.05). Furthermore, singer's formants were identified in all male operatic singers and in three female operatic singers. In contrast, only one applied music male and one female singer showed singer's formants while singing.

• Communications of the Korean Mathematical Society
• /
• v.12 no.3
• /
• pp.499-505
• /
• 1997

This paper is a continuation of [3]. We prove that if A is quasi-associative (resp. an implicative) ideal of a BCI-algebra X then the k-nil radical of A is a quasi-associative (resp. an implicative) ideal of X. We also construct the quotient algebra $X/[Z;k]$ of a BCI-algebra X by the k-nhil radical [A;k], and show that if A and B are closed ideals of BCI-algebras X and Y respectively, then

• Phonetics and Speech Sciences
• /
• v.5 no.1
• /
• pp.19-26
• /
• 2013

The aerodynamic characteristics (subglottal pressure (Ps) and mean airflow rate (MFR)), fundamental frequency (Fo), intensity (I), vocal efficiency (VE), and closed quotient (CQ) were compared during a sustained vowel /o/ sound under three conditions: in a comfortable loudness and pitch level (condition 1), in a maximum loudness level with a fixed pitch (condition 2), and in a maximum loudness level without a fixed pitch (condition 3). Also, multiple regression analyses were done to measure the aerodynamic characteristics affect on the VE and the CQ in each condition. The results showed the Fo, Ps, MFR, VE, and CQ increased as I increased with and without fixed pitch. Most notably, VE in condition 3 was the highest of all the conditions, but CQ was not very high. By the results of multiple regression analysis, VE was significantly affected by I and Ps in all conditions; Fo was the other main key for affecting VE in high pitch. However, none of the aerodynamic characteristics significantly affected CQ. As I increases, Fo should be increased by increasing Ps and VE. Therefore, researchers should consider and specify an a priori to Fo, Ps, and I when measuring VE to examine the complex and delicate vocal mechanism.

• Journal of the Korean Mathematical Society
• /
• v.32 no.3
• /
• pp.609-614
• /
• 1995

Let (M, g) be a complete Riemannian manifold and G be a closed (connected) subgroup of the group of isometries of M. Then the union ${\MM}$ of all principal orbits is an open dense subset of M and the quotient map ${\MM} \longrightarrow {\BB} := {\MM}/G$ becomes a Riemannian submersion for the restriction of g to ${\MM}$ which gives the quotient metric on ${\BB}$. Namely, B is a singular (complete) Riemannian space such that $\partialB$ consists of non-principal orbits.