• The korean journal of orthodontics
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• v.11 no.2
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• pp.101-108
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• 1981

This investigation was designed to compare the calcification degree of maxillary second permanent molar to mandibular second permanent molar in skeletal Class III Malocclusion. The material selected for this study consisted in standand lateral cephalogram study model and orthopantomogram of two hundred fifty seven Korean Children, one hundred twenty one boys and one hundred twenty four girls, aged 6 through 12 years, having skeletal Class III Malocclusion. On the basis of findigs of this study, the following results were obtained 1. In the stage of completion of crown, there was no significant difference in calcification degree between maxillary second molar and mandibular second molar of both boys and girls in skeletal Class III Malocclusion. 2. From 8 years of age at the stage of beginning root formation to 12 years of age, the calcification degree of mandibular second molar was more advanced than Maxillary second molar of both boys and girls in skeletal Class III Malocclusion.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.125-134
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• 1981

To study the calcification of second molars in skeletal class II malocclusion, the author examined cephalograms, orthopantomograms, periapical films of 391 children from 7y 0m to 15y 11 m years old who had skeletal class II malocclusion, and observed the difference in the calcification stage between upper and lower second molars. The result s are as follows. 1. The mean ages of crown completion of upper and lower second molars are $8.7{\pm}1.75$, $8.8{\pm}1.13$ in boys, and $8.4{\pm}0.81$, $8.5{\pm}0.91$ in girls. 2. The mean ages of root completion of upper and lower second molars are $14.0{\pm}1.09,\;14.5{\pm}0.52$ in boys, and $13.7{\pm}1.15,\;13.8{\pm}1.18$ in girls. 3. The calcification stages of upper second molars are more advanced than those of lower second molars at $5\%$ level in both sexes.

• Journal of the Korean Home Economics Association
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• v.48 no.10
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• pp.105-119
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• 2010

This study investigated the association between the expenditures for childrearing and the intention to have the second childbirth applying the recursive equation models. The major results were as follows. First, more than half of the households with one child did not have an intention to have the second childbirth. Second, about 40% of the household expenditure was spent for childrearing. About 36% of the childrearing expenditure was spent on the childcare and education, and about 64% on purchase of goods and services for child. Third, the variables which had a significant effect on the intention to have the second childbirth were child's age, mother's education, father's income, the private educational expenditure, and consumption expenditure for child. The intention to have the second childbirth did not have a significant effect on the level of childrearing expenditure. The implications for the family policies were suggested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.438-444
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• 2015

A new approach to the active phased arrays for the second harmonic generation is presented. Phase variation between the second harmonic oscillators by the mutual synchronization is analyzed theoretically. In this coupling, the active antenna consists of the FET oscillator which plays two roles in fundamental oscillation and frequency multiplying, and the patch antenna resonated at the second harmonic frequency. The radiated second harmonic wave was scanned by varying the free-running oscillation frequencies of the active antennas. In the experiment using the 2-elements array and the 4-elements array, the radiated beam of the second harmonic wave was scanned more widely compared with the case of the fundamental wave radiation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.53
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• pp.1-12
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• 1999

A warranty cost analysis for new products have received a lot of attention. In contrast, there is hardly any literature on similar analysis for second-hand products. The market of second-hand products has been increasing and along with that the importance of warranties for second-hand products has also been increasing. However, warranty policies similar to new products are not economically acceptable to dealers. One needs to formulate new warranty policies and models to estimate expected warranty costs for second-hand products. This paper proposes one-dimensional cost sharing warranty policies and develops models at system level to analysis warranty cost for second-hand products sold with these policies.

• The korean journal of orthodontics
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• v.19 no.3
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• pp.49-58
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• 1989

The permanent second molars, erupted about 12-13 years old, are finally erupted except wisdom teeth. Although they are likely to be excluded in the orthodontic treatment because located in the most posterior area of the dentition, about twenty percents of the orthodontic patients have abnormal occlusion of the permanent second molars, and we usually observed the malalignment of the permanent second molars in the finished case without including this teeth. These permanent second molars should be necessarily corrected by orthodontic appliances for the dynamic-normal occlusion. Moreover, according to the previously mentioned treatment philosophy, there are clear advantages in the cases which the permanent second molars were used for anchorage source, and this has been proposed convincingly by many authers. Therefore it is reasonable that orthodontists determine to include the permanent second molars among orthodontic treatment, but particular cases.

• Journal of the korean academy of Pediatric Dentistry
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• v.8 no.1
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• pp.21-24
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• 1981

The author observed a case of ectopic erupted maxillary second premolars and impacted mandibular second premolars due to premature loss of the primary second molars. The treatments were done as follows: 1. In the maxilla, the teeth arrangement problem was corrected with removal of the ectopic erupted second premolars. 2. In the mandible, normal dentition was established with surgical removal of the left second premolar and removal of the permanent first molar in right side combined by orthodontic therapy.

• The Korean Journal of Nuclear Medicine
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• v.5 no.1
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• pp.19-24
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• 1971

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.549-561
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• 2008

In this paper, we construct a pair of Wolfe type second order symmetric dual problems, in which each component of the objective function contains support function and is, therefore, nondifferentiable. For this problem, we validate weak, strong and converse duality theorems under bonvexity - boncavity assumptions. A second order self duality theorem is also proved under additional appropriate conditions.

• Journal of applied mathematics & informatics
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• v.35 no.5_6
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• pp.599-609
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• 2017

We construct degenerated Euler polynomials of the second kind and find some basic properties of this polynomials. From this paper, we can see degenerated alternative power sum is defined and is related to degenerated Euler polynomials of the second kind. Using this power sum, we have a number of symmetric properties of degenerated Euler polynomials of the second kind.