• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.36-42
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• 2020

The maturation and spawning of white crocker Pennahia argentatus were investigated using samples collected in the Southern Sea of Korea from January to December 2018. We analysed monthly changes in maturity stage, gonad-osomatic index (GSI), total length (TL) at 50% group maturity. The spawning period was May to July. Fecundity varied between 71,627 and 888,041 eggs. The relationship between the fecundity and TL of the fish was expressd in the fecundity equation as F=0.2198TL^4.2784 (r²=0.8423). The percentage of sexually mature females estimated from a logistic function was over 50% for the size group 19.33 cm (total length, TL).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.449-458
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• 2013

This study investigated purplish Washington clam, Saxidomus purpuratus on its gonadal development, reproductive cycle and shell length (age) at 50% female group maturity from January to December 2011 in Jinhae Bay, Korea. This species is dioecious. The gonad index (GI) began to increase in January, reached the maximum value in May and to decrease in June, reached the minimum value in September then to increase slowly in October again. The reproductive cycle of the clams can be divided into five successive stages: the early active stage (Ea, from February to March), the late active stage (La, from January to March and October to December), the ripe stage (R, from January to May), the spawning stage (S, from June to December) and the degenerative and inactive stage (Ia, from January to February and November to December). The spawning periods were from June to December and the main spawning periods were from July to October. The shell length at 50% female group maturity (SL50) was estimated to be 63.6 mm, which can be converted as sexual maturity age of 2.2 year.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.1 no.1
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• pp.42-45
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• 1963

In a plant breeding program, an efficient selection of desired characters in a population is important. Generally, many agronomic characters in a given population are determined by polygenes and quantitatively inherited. In practice, the genetic relationship between two observed characters which are undoubtedly subjected to the environmental influence is difficult to identify. In recent years, many workers have attempted to understant the genetic relationship between characters in terms of genotypic correlation, and the knowledge thus gained should furnish many important and useful information for the planning of breeding, selection, and interpretation of the result. The genotypic correlation is the result of pleiotropy, linkage of genes(2, 3, 5, 6, 8) and natural or artificial selection(4). The purposes of this study were to estimate genotyric and phenotypic correlations between all possible pairs of nine characters. and to seek certain characters which may be useful as indicators of certain important agronomic characters. Weber and Moorthy(10), Johnson et al. (5) and Sheth(7) found that in general, the genotypic correlations were higher than the phenotypic correlations. Weiss et al. (11) obtained significant positive correlations between maturity and oil content, maturity and low protein content, and high protein content and low oil content. Weber and Moorthy(10) reported the positive genotypic correlations between flowering and maturity, yield and maturity, yield and plant height, yield and seed weight, and negative genotypic correlations between maturity and oil content, and oil content and seed weight. Johnson et al. (5) studied the genotypic and phenotypic correlations among 24 characters and concluded that selection based entirely on a long fruiting period, lateness, heavy seed, low protein, high oil and resistance to lodging would be effective in increasing yield. Sheth(7) found the following positive associations among characters; height and maturity, yield and lodging, low protein content and high oil content, and yield and low protein content. Hanson et al.(1) also reported high negative correlation between seed yield and protein content.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.367-375
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• 2016

Marbled flounder Pseudopleuronectes yokohamae is a commercially important flatfish in the coastal waters of the East Sea off Pohang, Korea. Maturity and spawning dynamics of P. yokohamae were investigated based on samples collected by gill net and long line in the coastal waters off Pohang from January 2013 to December 2014. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. We found that the spawning period was December to February, wherein fecundity ranged from 55,760 eggs at 20.40 cm total length (TL) to 1,559,007 eggs at 46.6 cm TL. The relationship between TL and fecundity (F) was F = 0.0017 TL^3.5604 (R² = 0.6984), and F increased with increasing TL. We estimated the TL at 50% group maturity as 27.4 cm for female and 23.5 cm for male P. yokohamae, respectively. The results from this research will aid in the development of policies on season and minimum catch length for sustainable production of P. yokohamae. We propose that it is necessary to conduct long-term ecological monitoring for this species because biological properties such as spawning ecology and growth performance are being affected by climate change.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.197-209
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• 1985

To investigate the relationship between the pubertal spurt in body height and bone maturity of the hand-and-wrist in normal occlusion, the author X-rayed the hand-and-wrists of 1,141 students (male 614, female 527) and assessed their bone maturity. In this study, eleven skeletal stages were selected. The bones used to determine skeletal maturity were the ulnar sesamoid of the metacarpophalangeal joint of the first finger, the epiphyses of the proximal, middle, distal phalanges of the third finger, and middle phalanx of the fifth finger, and distal epiphysis of the radius. From the longitudinal data for height, an assessment was made of the change in growth velocity. The pubertal growth stage was divided into onset and peak height velocity phases. The results were as follows; 1. The onset of the pubertal growth was between the $PP_3=\;and\;MP_3=$ stage for boys, and between the $MP_3=\;and\;MP_5=$ stage for girls; the mean age of onset was 10.6 years for boys and 9.0 years for girls. 2. The peak height velocity was between the S and $MP_{3_{cap}}$ stage for boys, and between the $MP_{3_{cap}}$ and $MP_{5_{cap}}$ stage for girls; the mom age of peak height velocity was 12.5 years for boys and 10.9 years for girls. 3. As the stages of bone maturity progressed from $DP_{3u},\;to\;PP_{3u},\;MP_{3u}$, Ru, the peak height velocity had been reached, and the growth rate retarded, therefore the approach to full physical maturity was attained. 4. The evidence for the period of onset, peak height velocity and bone maturation suggested that girls were in advance of boys. During the latter part of pubertal growth, the rate of boys' bone maturation was faster than that of girls'.

• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.503-508
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• 2023

The purpose of this study was to examine the impact of emotional intelligence and cognitive emotion regulation strategies on career maturity among university students during this period of increasing employment challenges. The study participants consisted of 348 students who attended general education courses at a 4-year N University located in Chungnam. The analysis was conducted using SPSS 26.0, and descriptive statistics, correlation analysis, and regression analysis were applied. The research findings indicated a significant correlation between emotional intelligence and cognitive emotion regulation strategies with career maturity among university students. The results suggested that positive thinking and motivation related to their emotions and feelings could enhance career maturity. Based on these findings, it is expected that various research and programs aiming to enhance career maturity will be promoted in the future. Additionally, the study aspires to serve as foundational data in devising concrete and achievable strategies for career and employment fields.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.243-258
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• 2008

The purpose of this study was to investigate the relationship between the stages of calcification of various teeth and skeletal maturity stages among Korean individuals. The study subjects consisted 154 female and 179 male ranging from 7 years to 16 years of age. A total of 333 hand-wrist, cephalo-lateral and panoramic radiographs were obtained and analyzed. The tooth development of the mandibular canines, first, second premolars, and second molars were assessed according to the Dermijian's system. Skeletal maturity stages were determined from hand-wrist radiographs by using the SMI system and cephalo-lateral radiographs by using the CVMS, respectively. The results were as follows. 1. The mean ages of each stage of skeletal maturity were consistently younger in female subjects. 2. There was a high correlation between skeletal maturity of hand-wrist and cervical vertebrae in the both sexes. 3. There was a high correlation between skeletal maturity and dental calcification stage of mandibular canines, first premolar, second premolars, and second molar. 4. The mandibular second molar was tooth showing the highest correlation. 5. Percent distributions of the relationship between calcification stages of individual teeth and stages of skeletal maturity were obtained in both sexes. In summary, this suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.646-653
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• 2003

Investigations were made on the population structure, sex ratio, growth, and recruitment patterns of Leptochela sydniensis in the southwestern coastal areas of Korea, between May 2000 and December 2001. Spawning period, fecundity, brood loss, reproductive output, and size at sexual maturity also were examined. The results of the sex ratio showed that females were more numerous than males during the overall study period. Parameters of growth were estimated using the modified von Bertalanffy growth function (VBGF) model incorporating seasonal variation into growth. Females grew somewhat faster and reached a larger size than males $(L\infty=12.80\;mm\;CL\;and\;K=0.70\;yr^{-1}\;or\;females,\and\;L\infty=12.08\;mm\;CL\;and\;K=0.69\;yr^{-1}$ for males). The structure of recruitment patterns obtained by the FiSAT program indicated one normally distributed group. Based on the occurrence of ovigerous females and the gonadosomatic index (GSI), the main spawning season was from June to August. Analysis of covariance indicated that brood loss was not observed during the incubation period. The size at which $50\%$ of females are mature is estimated as 5.48 mm CL.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.179-184
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• 2007

Maturity and spawning of spinyhead sculpin, Dasycottus setiger were investigated using samples collected by the eastern sea danish seine and gillnet in the East Sea of Korea from January to December 2004. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), egg diameter, fecundity, total length at 50% group maturity, and sex ratio. GSI began to increase in August, reached a maximum between September and November, and decreased in December. The spawning period was August to December, and the main spawning period was September to November. The fecundity ranged from 6,210 eggs at 22.3 cm (TL) to 15,898 eggs at 32.2 cm (TL). The relationship between total length (TL) and fecundity (F) was $F=25.475TL^{1.818}$ ($R^2=0.761$), and F increased with TL. The TL at 50% group maturity was estimated to be 23.4 cm. The sex ratio was 1 : 1.3 (female : male), indicating the male population was seem to be slightly predominant.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.255-268
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• 2021

The aim of this study was to investigate the relationships between the stages of calcification of various teeth and skeletal maturity stages among Korean subjects. The samples were derived from hand-wrist, panoramic radiographs, and lateral cephalograms of 743 subjects (359 males and 384 females) with ages ranging from 6 to 14 years. Calcification of seven permanent mandibular teeth on the left side were rated according to the system of Demirjian. To evaluate the stage of skeletal maturation, hand-wrist radiographs were analyzed by skeletal maturity indicators (SMI) system of Fishman and lateral cephalograms by cervical vertebral maturation (CVM) method of Baccetti. Statistically significant relationships were found between dental calcification and skeletal maturity stages according to Spearman rank-order correlation coefficients (r = 0.40-0.84, p < 0.001). The second molar showed the highest correlation and central incisor showed the lowest correlation for female and male subjects. For both sexes, canine stage G and second molar stage F were related to SMI 6 and CS 3. Because of the high correlation coefficients, this study suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period in Korean patients.