• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.81-90
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• 2013

During adolescence the mutational period is characterized by the changes in the laryngeal structure, the length of the vocal cords, and a tone of voice. Usually, adolescents at 15 or 16 reach the voice of adults but the mutational period is sometimes delayed. Therefore, studies on the voice of adolescents between 16 ~ 18 right after the mutational period are required. Accordingly, this paper attempted to provide basic data about the normal standard for patients with voice disorders during this period by evaluating the vocal characteristics of males and females between 16 ~ 18 with an objective device bycomparing and analyzing them by sex and age. The study was conducted on a total of 60 subjects composed of each 10 subjects of each age. The vocal analysis was conducted by MPT (Maximum Phonation Time) measurement, sustained vowels and sentence reading. As for /a/ sustained vowels, fundamental frequency, hereinafter referred to as $F_0$, jitter, shimmer, noise-to-harmonic ratio, hereinafter referred to as NHR were measured by using the Multi-dimensional voice program (MDVP) among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). The sentence reading, mean $F_0$, maximum $F_0$ and minimum $F_0$ were measured using the Real-Time Pitch (RTP) Model 5121 among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). As a result, according to sex, there were statistically significant differences in $F_0$, jitter, shimmer, mean $F_0$, maximum $F_0$, and minimum $F_0$; and according to age, there were statistically significant differences in MPT. In conclusion, the voice of the adolescents between 16 ~ 18 reached the maturity levels of adults but the voice quality which can be considered on the scale of voice disorders showed transition to the voice of an adult during the mutational period.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.329-341
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• 2010

The purpose of this study was to examine vegetable & fruit (V/F) intakes, beliefs and self-efficacy regarding V/F consumption, nutrition knowledge and eating behavior of elementary students. A survey was conducted to the 4th graders (n = 234) at two elementary schools in Guri, Kyunggi-do. About one-fourth of subjects were overweight or obese. Subjects had 4.2 servings of V/F a day, consuming 340.2 g of V/F. Girls consumed significantly more amounts of vegetables than boys (p < 0.05). Girls were more favorable regarding V/F consumption (p < 0.01), and believed more strongly on advantages of having V/F such as “good for skin” constipation prevention (p < 0.001) and cancer prevention (p < 0.05). Boys felt more strongly in disadvantages or barriers of eating V/F, including mother's cooking time constraints (p < 0.01), lack of past experience of eating V/F, and family members' disliking of V/F (p < 0.05). Girls felt more confident in eating V/F (p < 0.05) than boys; they also felt more confident in specific items of "eating fruits/salads instead of cookies/chips for snack" and "eating fruit juice/vegetable juice instead of soda"(p < 0.01). Subjects showed low level of nutrition knowledge, especially in items such as balanced meals, recommended servings of V/F and vitamin deficiency. Compared to boys, girls had more desirable eating behavior such as eating adequate amount of meals (p < 0.001), having a variety of foods, eating fruits daily, and having fatty foods less frequently (p < 0.05). Intakes of Ca and K were quite below the recommended level, while the intakes of protein, Na and vitamin A intake were much above the Dietary Reference Intakes (DRI) for 9-11 old children. Nutrient intakes expressed as %DRI was higher in girls for vitamin A (p < 0.01), energy and riboflavin (p < 0.05). High V/F consumption group (${\geq}5$ servings of V/F a day) compared to the counterparts showed higher self-efficacy and had better eating behaviors. Nutrition education for children should focus on increasing consumption of V/F, by helping them to increase self-efficacy for eating V/F and to recognize the benefits and reduce the barriers of eating V/F, especially in boys. It is also needed to provide nutrition information for balanced meals or increasing V/F consumption, and help the children to adopt desirable eating behavior.

• Speech Sciences
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• v.14 no.4
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• pp.251-260
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• 2007

The structure changes of the vocal folds are related to the fundamental frequencies (F0). In other words, the increasing in vocal fold length and thickness makes the result of dropping in the F0 during the mutational period. The purpose of this study was to investigate F0 of normal children's voice in mutational period. 360 children (180 boys and 180 girls) were participated in this experiment. The age was ranged from 11 to 16 years. The subjects were asked to produce sustained comer vowels (/a/ /i/ /u/) five times each and the data were analyzed using the MDVP of CSL. The result shows that the F0 are considerably decreased with age and reach to adults' F0 by 16 years in most cases. In particular, the F0 of male subjects were rapidly decreased between the ages from 12 ($226.98\;{\pm}\;19\;Hz$) to 13 years ($169.3\;{\pm}\;25\;Hz$), while the F0 of female subjects were slowly changed from the later period of 12 to 16 years old. This result may be used by the meaning of guideline and lead the basic data to differentiate between normal voice and voice disorder.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.133-137
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• 2003

The purpose of this study was to provide acoustic data on the voice of the laryngectomized patients for more scientific and efficient voice rehabilitation. The phonation of prolonged /a/ of 9 electronic artificial larynx(AL) users, 5 esophageal(EP) speech users, and 2 tracheo-esophageal(TEP) voice users were recorded and analyzed using Multi-Speech. Habitual f0, mean f0, sd f0, max f0, min f0, jitter, shimmer, and NHR were compared among groups of subjects using t-test. The EP and TEP groups exhibited higher f0 compared to the AL group. The AL and TEP groups showed more stable f0 than the EP group. In addition, the quality of TEP and EP voices were comparatively better in terms of jitter, shimmer, and NHR.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.41-47
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• 2017

The purpose of this study is to examine how speakers use VOT and f0 to distinguish tense, lax, and aspirated stops in isolated sentence reading and paragraph readings. To do so, a total of 20 males between the ages of 20-25 years old were asked to read (1) isolated sentences, (2) information-oriented text and (3) emotional expressive texts in which the stop pronunciation's VOT value and f0 were measured thereafter. The main results are as follows. In the isolate sentence reading, lax stops, and aspirated stops were distinguished by both VOT and f0, but for the Korean men that read reading texts, VOT is not a cue to distinguish between lax and aspirated stops. In general, the VOT differences between lax stops and aspirated stops were smaller for information-oriented texts and emotional expressive texts than that of the isolate sentence reading. In the paragraph reading that induces a natural utterance, the f0 dependence is greater for the distinction between lax and aspirated stops.

• Journal of the Korean Mathematical Society
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• v.31 no.4
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• pp.609-618
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• 1994

F. Rhodes [2] introduced the fundamental group $\sigma(X, x_0, G)$ of a transformation group (X,G) as a generalization of the fundamental group $\pi_1(X, x_0)$ of a topological space X and showed a sufficient condition for $\sigma(X, x_0, G)$ to be isomorphic to $\pi_1(X, x_0) \times G$, that is, if (G,G) admits a family of preferred paths at e, $\sigma(X, x_0, G)$ is isomorphic to $\pi_1(X, x_0) \times G$. B.J.Jiang [1] introduced the Jiang subgroup $J(f, x_0)$ of the fundamental group of X which depends on f and showed a condition to be $J(f, x_0)$ = Z(f_\pi(\pi_1(X, x_0)), \pi_1(X, f(x_0)))$.

• Journal of Korea Water Resources Association
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• v.45 no.2
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• pp.137-149
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• 2012

Field measurements of resistance to flow are analyzed for 739 rivers vegetated with grass (281 channels), shrubs (150 channels) and trees (308 channels). The measured distribution of Manning roughness coefficients ranges from 0.015~0.250 for grass, 0.016~0.250 for shrubs, 0.018~0.310 for trees. Significant trends are obtained between Darcy-Weisbach (or Manning roughness coefficients) and flow discharge, friction slope, and relative submergence. The regression equations for Darcy-Weisbach and Manning roughness coefficients in vegetated rivers are: $f_{veg}=0.436Q^{-0.363}$, $f_{veg}=3.305S_f^{0.508}$, and $n_{veg}=0.061Q^{-0.124}$, $n_{veg}=0.144S_f^{0.199}$, $V=5.3(h/d_{50})^{1/8.3}{\sqrt{ghS_f}}$, $\sqrt{8/f}(=V/u*)=5.75log(5h/d_{50})$, respectively. These semi-empirical relationships should be useful for hydraulic engineering practice.

• Journal of Korean Dental Hygiene Science
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• v.4 no.2
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• pp.9-18
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• 2021

Background: Based on the individualistic approach of experienced dental hygienists, this study attempted to provide basic data to find effective measures of human resource management by analyzing the correlation between organizational socialization and professional self-concept. Methods: Dental hygienists currently working in the Daegu area were evaluated. Nine questions related to duties, twenty-seven questions related to professional self-concept, and thirty-eight questions related to organizational socialization were included in the study. The reliability was professional self-concept (Cronbach's α = 0.859) and organizational socialization (Cronbach's α = 0.840). Results: Of the total 135 points for professional self-concept, the mean score of the participants was 62.67±8.45 points. In the sub-area, flexibility was the highest at 19.28±2.46 points, and communication was the lowest at 9.69±1.44 points. Of 190 points, organizational socialization averaged at 123.40±12.82 points. In the subarea, personal characteristics were the highest at 30.37±3.71 points, and occupational identity was the lowest at 10.34±1.94. Higher age (F=30.89, p<0.000), marital status (F=10.22, p<0.002), graduate or higher educational qualification (F=9.16, p<0.000), were associated with a higher position (F=20.62, p<0.000) and work experience (F=22.66, p<0.0000), when there was no intention to turnover (F=8.05, p<0.000). Organizational socialization was higher in participants with higher age (F=7.89, p<0.000), educational qualification (F=8.02, p<0.000), and position (F=5.12, p<0.007); higher work experience in general hospital (F=4.50, p<0.012); no intention to turnover (F=7.450, p<0.000); and no intention to turnover (F=24.46, p<0.000). Organizational socialization showed a significant positive correlation with professional self-concept (r=0.721, p<0.000); job performance and skills (r=0.615, p<0.000) and organizational commitment and satisfaction (r=0.610, p<0.000) showed a high positive correlation. Turnover intention (β=0.213, p<0.000) was found to have a significant effect on organizational socialization. Leadership (β=0.168, p<0.05) and satisfaction (β=0.483, p<0.000) were found to have a significant effect. The total explanatory power of this variable was 62.7%. Conclusion: To ensure successful organizational socialization, human resource management should be performed through regular verification, which can result in improved quality of dental care services.

• Bulletin of the Korean Mathematical Society
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• v.22 no.2
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• pp.83-85
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• 1985

Let K be a real function field over a real closed field F. Then there exists an F-place .phi.:K.rarw.F.cup.{.inf.}. This is Lang's Existence of Rational Place Theorem (6). There is an equivalent version of Lang's Theorem in (4). That is, if K is a function field over a field F, then, for any ordering P$_{0}$ on F which extends to K, there exists an F-place .phi.: K.rarw.F'.cup.{.inf.} where F' is a real closure of (F, P$_{0}$). In [2], Knebusch pointed out the converse of the version of Lang's Theorem is also true. By a valuation theoretic approach to Lang's Theorem, we have found out the following generalization of Lang and Knebusch's Theorem. Let K be an arbitrary extension field of a field F. then an ordering P$_{0}$ on F can be extended to an ordering P on K if there exists an F-place of K into some real closed field R containing F. Of course R$^{2}$.cap.F=P$_{0}$. The restriction K being a function field of F is vanished, though the codomain of the F-place is slightly varied. Therefore our theorem is a generalization of Lang and Knebusch's theorem.

• Journal of the Korean Ceramic Society
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• v.38 no.11
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• pp.1046-1054
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• 2001

Effects of B$_2$O$_3$and CuO addition on the microwave dielectric properties of the PbWO$_4$-TiO$_2$ceramics were investigated in order to use this material as an LTCC material for fabrication of a multilayered RF passive components module. We found that PbWO$_4$could be used as an LTCC material because of its low sintering temperature (8$50^{\circ}C$) and fairy good microwave dielectric properties($\varepsilon$$_{r}$=21.5, Q$\times$f$_{0}$=37200 GHz and $\tau$$_{f}$ =-31 ppm/$^{\circ}C$). In order to stabilize $\tau$$_{f}$ of PbWO$_4$, TiO$_2$was added to the PbWO$_4$and the mixture was sintered at 8$50^{\circ}C$. A near zero $\tau$$_{f}$ value (+0.2 ppm/$^{\circ}C$) was obtained with 8.7 mol% TiO$_2$addition. $\varepsilon$r and Q$\times$f$_{0}$ values were 22.3 and 21400 GHz, respectively. It was believed that the decrement of Q$\times$f$_{0}$ value with TiO$_2$addition was resulted from increasing grain boundary. In order to improve Q$\times$f$_{0}$, various amounts of B$_2$O$_3$and CuO were added to the 0.913PbWO$_4$-0.087TiO$_2$mixture. The optimum amount of CuO was 0.05 wt%. At this addition, the 0.913PbWO$_4$-0.087TiO$_2$ceramic showed $\varepsilon$$_{r}$=23.5, $\tau$$_{f}$ =-2.2ppm/$^{\circ}C$, and Q$\times$f$_{0}$=32900 GHz after sintered at 8$50^{\circ}C$. In case of B$_2$O$_3$addition, the optimum amount range was 1.0~2.5 wt% at which we could obtain following results; $\varepsilon$$_{r}$=20.3~22.1, Q$\times$f$_{0}$=48700~54700 GHz, and $\tau$$_{f}$ =+2.4~+8.2ppm/$^{\circ}C$.