• East Asian mathematical journal
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• v.34 no.1
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• pp.29-37
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• 2018

We introduce formal symbols of product type, of zero class, and of minimum type and show that the formal power series representations for $e^p$ and $e^q$ are formal symbols of product type giving the same pseudodifferential operator, where p and q are formal symbols of minimum type and p - q is of zero class.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.87-90
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• 2005

High-efficiency switched-mode circuits such as the class-E amplifier are well-known in the MHz frequency range. The class-E amplifier is a type of switching mode amplifier offering very high efficiency approaching 100%. In this paper of the class-E amplifier by using pHEMT device, the design has been done theoretically and experimentally, with simulation by using the harmonic balance method using circuit simulator. The amplifier using microstrip circuit and the pHEMT demonstrate 66% power-added- efficiency (PAE) at 2.4GHz with 17.6dBm of output power.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.519-540
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• 1999

The purpose of this study is to compare the healing aspects of the use of ePTFE membrane alone versus combination treatment of ePTFE membrane and bone grafts on class II furcation defects. Seventeen defects were applied ePTFE membrane alone on mxillary molar buccal class II furcation defects as Group I, seventeen defects were applied ePTFE membrane and bone grafts on maxillary molar buccal class II furcation defects as Group II, twenty-three defects were applied ePTFE membrane alone on mandibular molar buccal class II furcation defects as Group III, twenty defects were applied ePTFE membrane and bone grafts on mandibular molar buccal class II furcation defects as Group IV . Measurements were made to determine clinical attachment level, probing depth, gingival depth, SBI, mobility at baseline, 3, 6, 12 months postoperatively. Additional measurements were made to determine membrane exposure level at surgery, 1, 2, 6 weeks postoperatively. And then healing patterns and postoperative complications were evaluated. The result as follows : There were statistically significant differences in probing depth reduction, clinical attachment gain, mobility reduction at values of 3, 6, 12 months postoperatively compared to values of baseline(p<0.05), whereas no significant differences in SBI and gingival recession. In group II, membrane exposure level was increased at 1, 2, 6 weeks postoperatively compared to value of baseline(p<0.05). There were statistically significant differences in changes of probing depth at 3, 6, 12 months postoperatively in combination groups of ePTFE membrane and bone graft compared to groups of ePTFE membrane alone(p<0.05). The vast majority of cases fall into typical healing and delayed healing response when membranes were removed in all groups. Pain and swelling were common postoperative complications. In conclusion, this study was showed more effective healing aspects in combination treatment of ePTFE membrane and bone graft than ePTFE membrane alone and on mandibular molar class II furcation defects than maxillary molar.

• Kyungpook Mathematical Journal
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• v.48 no.3
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• pp.359-366
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• 2008

Let A(p) be the class of functions $f\;:\;z^p\;+\;\sum\limits_{j=1}^{\infty}a_jz^{p+j}$ analytic in the open unit disc E. Let, for any integer n > -p, $f_{n+p-1}(z)\;=\;z^p+\sum\limits_{j=1}^{\infty}(p+j)^{n+p-1}z^{p+j}$. We define $f_{n+p-1}^{(-1)}(z)$ by using convolution * as $f_{n+p-1}\;*\;f_{n+p-1}^{-1}=\frac{z^p}{(1-z)^{n+p}$. A function p, analytic in E with p(0) = 1, is in the class $P_k(\rho)$ if ${\int}_0^{2\pi}\|\frac{Re\;p(z)-\rho}{p-\rho}\|\;d\theta\;\leq\;k{\pi}$, where $z=re^{i\theta}$, $k\;\geq\;2$ and $0\;{\leq}\;\rho\;{\leq}\;p$. We use the class $P_k(\rho)$ to introduce a new class of multivalent analytic functions and define an integral operator $L_{n+p-1}(f)\;\;=\;f_{n+p-1}^{-1}\;*\;f$ for f(z) belonging to this class. We derive some interesting properties of this generalized integral operator which include inclusion results and radius problems.

• Honam Mathematical Journal
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• v.15 no.1
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• pp.75-85
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• 1993

For A and B, $-1{\leq}B<A{\leq}1$, let P[A, B] be the class of functions p analytic in the unit disk E with P(0) = 1 and subordinate to $\frac{1+Az}{1+Bz}$. We introduce the class $T_{\alpha}[A,B]$ of functions $f:f(z)=z+\sum\limits_{n=2}^{{\infty}}a_nz^n$ which are analytic in E and for $z{\in}E$, ${\alpha}{\geq}0$, $[(1-{\alpha}){\frac{f(z)}{z}}+{\alpha}f^{\prime}(z)]{\in}P[A,B]$. It is shown that, for ${\alpha}{\geq}1$, $T_{\alpha}[A,B]$ consists entirely of univalent functions and the radius of univalence for $f{\in}T_{\alpha}[A,B]$, $0<{\alpha}<1$ is obtained. Coefficient bounds and some other properties of this class are studied. Some radii problems are also solved.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.2
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• pp.81-89
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• 2022

Purpose: Wireless endodontic handpieces (WEH) are widely used in dental clinics due to their convenience and portability. This study aimed to compare the vibration magnitudes and patterns generated by five WEH. Materials and Methods: Vibration acceleration of five WEH (X-Smart IQ, E connect S, Endo A Class, ENDOIT, and TRAUS ENDO) in the rotary and reciprocating motion was measured with accelerometer The average vibration acceleration was analyzed using the t-test, Welch's ANOVA test, and Dunnett T3 test at P < 0.05. Results: In all WEH, the average vibration acceleration in reciprocating motion was significantly higher than that in rotary motion (P < 0.001). In rotary motion, repeated vibration graphs of constant amplitude were obtained without sudden changes in the magnitude of vibration, and the average vibration acceleration value was high in the order of X Smart IQ, Endo A Class, ENDOIT, E Connect S, and TRAUS ENDO (P < 0.001), there was no statistically significant difference between X Smart IQ and Endo A Class. In reciprocating motion, a vibration graph was obtained in which large amplitude peaks appear at specific points within one cycle are repeated. The average vibration acceleration value was highest in the order of X Smart IQ, E Connect S, Endo A class, ENDOIT, and TRAUS ENDO (P < 0.001). Conclusion: Regardless of the type of WEH, greater vibration occurred in the reciprocating motion than in the rotary motion (P < 0.001). In the reciprocating motion, there was a difference in vibration for all handpieces (P < 0.001).

• Journal of the Korean Mathematical Society
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• v.49 no.4
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• pp.671-686
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• 2012

This paper mainly deals with the tilted Carath$\acute{e}$odory class by angle ${\lambda}$ ${\in}$ ($-{\pi}/2$, ${\pi}/2$), denoted by $P{\lambda}$) an element of which maps the unit disc into the tilted right half-plane {<${\omega}$ : Re $e^{i{\lambda}}{\omega}$ > 0}. Firstly we will characterize $P{\lambda}$ from different aspects, for example by subordination and convolution. Then various estimates of functionals over $P{\lambda}$ are deduced by considering these over the extreme points of $P{\lambda}$ or the knowledge of functional analysis. Finally some subsets of analytic functions related to $P{\lambda}$ including close-to-convex functions with argument ${\lambda}$, ${\lambda}$-spirallike functions and analytic functions whose derivative is in $P{\lambda}$ are also considered as applications.

• Communications of the Korean Mathematical Society
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• v.38 no.3
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• pp.715-723
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• 2023

In this paper, we construct explicitly an infinite family of primes P with h^±_P ≡ 0 (mod q^{deg P}), where h^±_P are the plus and minus parts of the divisor class number of the P-th cyclotomic function field over 𝔽_q(T). By using this result and Dirichlet's theorem, we give a condition of A, M ∈ 𝔽_q[T] such that there are infinitely many primes P satisfying with h^±_P ≡ 0 (mod p^e) and P ≡ A (mod M).

• Korean Journal of Child Studies
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• v.18 no.2
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• pp.241-265
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• 1997

The purpose of this study was to investigate effects of Parent Effectiveness Training (P. E. T.) on (1) parental awareness and verbal control patterns of mothers and (2) the relationship between parental awareness and verbal control patterns of mothers. The subjects were 43 mothers whose children were in 3rd, 4th, 5th, and 6th grades in one of two elementary schools in the City of Seoul. Mothers who participated in a P. E. T. class were assigned either to an experimental or a control group. Mothers in the experimental group received P. E. T. during the study; those in the control group received it after the study. Instruments were the Parental Awareness Interview (Newberger, 1980) and the revised Verbal Control Patters (Gumperz, 1973) for mothers. The data were analyzed by t-tests and Pearson's correlations. The results showed that (1) P. E. T. influenced parental awareness of mothers, and this change was maintained one month after completion of the P. E. T. class. (2) Mothers' verbal control patterns were changed by P. E. T. Specifically, mother' imperative and positional verbal control patterns decreased while personal verbal control patterns increased after P. E. T. (3) P. E. T. was negativeiy related to mother's imperative and positional verbal control patterns but positively related to personal verbal control patterns.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.170-180
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• 2020

Objective: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. Methods: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. Results: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion-pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. Conclusions: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.