• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.591-595
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• 2003

Settlement of larvae, growth, and survival of juvenile abalone (Haliotis discus hannai) were examined after feding of 5 species of benthic diatoms (Cocconeis suctellum, Navicula sp Nitzschia longissima Bacillavia paxillifera, Licmophora flabellata). All of the benthic diatoms were isolated from natural populations on plastic plates for the abalone. The settlement of larvae, shell growth, and survival rate of juvenile abalone varied by diatoms species. The highest settlement rate of larvae was $43.1\%$ with the Cocconeis suctellum diet. Daliy growth rate reached a maximum at 64.1 ${\mu}m/day$ with the Navicula sp. diet and a minimum at 22.4 ${\mu}m/day$ with the Licmophora flabellata diet. Survival rate of the juvenile abalone was highest at $62.0\%$ with the Navicula sp., Cocconeis suctellum , and Nitzschia longissima diets. Survival rate of the Juvenile abalone was significantly higher than the control group with mixed diatom population diets (P<0.05). Therefore, diatom . species composition in diets can be a controling factor for the settlement, growth, and survival rates of Juvenile abalone.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.247-254
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• 2015

This study is to explore the effects of adolescent's stress on juvenile delinquents and the moderating effects of communication between adolescent and the parents. For this study, we sampled and surveyed middle school students. The analytical results are the followings. Juvenile's stress has a significant effects on juvenile's delinquents and the level of communication between juveniles and the parents is an important factor concerned with juvenile's delinquents. This study suggested some policy implications based on this results.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.751-757
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• 2022

To develop a trap to prevent the catch of juvenile rockfish Sebastes inermis and bycatch, we compared the fishing characteristics of four traps with different mesh sizes (35 mm and 50 mm) and flapper connecting lines (FCL) (3 lines and 4 lines).The number of rockfish caught in trap 1 (35 mm, 4 FCL) was 200, and juvenile rockfish (15 cm or less) accounted for 49.0%. The number of rockfish caught in trap 2 (35 mm, 3 FCL) was 185, and juvenile rockfish accounted for 58.9%. The number of rockfish caught in trap 3 (50 mm, 4 FCL) was 82, and juvenile rockfish accounted for 4.9%. The number of rockfish caught in trap 4 (50 mm, 3 FCL) was 68, and juvenile rockfish accounted for 22.1%. The total catch (bycatch rate) in trap 1, trap 2, trap 3 and trap 4 was 565 (64.6%), 637(71.0%), 260 (68.5%) and 276 (75.4%), respectively. The catch per unit effort (CPUE) for juvenile rockfish in trap 1, trap 2, trap 3 and trap 4 was 0.8, 0.9, 0.0, and 0.1 individuals/trap, respectively. The CPUE of bycatch in trap 1, trap 2, trap 3 and trap 4 was 2.9, 3.6, 1.4 and 1.7 individuals/trap, respectively.

• Korean Journal of Culture and Social Issue
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• v.9 no.1
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• pp.81-114
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• 2003

This study examines the basis and change of delinquent behavior among Korean adolescents. Theoretical framework was developed and qualitative analysis of delinquency behavior was examined. In order to understand the basis and change of juvenile delinquency, the influence of family environment, school environment and individual factors were investigated through cross-sectional and longitudinal studies. The results of the findings can be summarized into the following six main points: 1) two subcultures of adolescent functioning could be ascertained, 2) the decrease in social support and increase in moral disengagement were directly related to a rise in juvenile delinquency, 3) family disintegration contributed to juvenile delinquency, 4) peer influence help to raise juvenile delinquency, 5) schools were unable to give hope to those students who were not doing well in school and were ineffective in dealing with juvenile delinquents, and 6) the phenomenon of juvenile delinquency points to the importance of opening up the closed school system and closed society, allowing individual diversity and skills to be recognized.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.133-139
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• 2016

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.59-68
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• 2021

The purpose of this study is to develop a personality education tea culture therapy program to effectively improve juvenile delinquency prevention and social adaptation. In order to verify the effectiveness of the tea culture therapy program through social intervention, we analyzed whether there were significant differences in the scores of social characteristics such as self-efficacy, self-control, and interpersonal relationships of juvenile detention students before and after participating in the program. Ten juvenile detention students between the ages of 14 and 17 who were accommodated to a juvenile detention center in B city were selected as the experimental group for the study. The tea culture therapy program was conducted 10 times as a social intervention personality education for juvenile delinquents, and as a result, self-efficacy was found to have a pre-mean of 2.37 (SD 0.33) and a post-mean of 2.49 (SD 0.31), showing a significant difference (Z=-5.874. P=.000), self-control showed a significant difference with the pre-mean 2.06 (SD 0.20) and the post-mean of 2.16 (SD 0.19) (Z=-4.743, P=.001). The interpersonal relationship was found to have a significant difference, with a pre-mean of 1.90 (SD 0.32) and a post-mean of 2.15 (SD 0.21) (Z=-5.892, P=.000). The above results show that this program has a significant effect on improving social characteristics such as self-efficacy, self-control, and interpersonal relationships among juvenile detention students. Therefore, the tea culture therapy program developed in this study for personality education for juveniles can be used as a personality education program for various types of adolescents as well as in the field of correctional welfare in the future.

• Journal of the Korean Society of Food Culture
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• v.24 no.6
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• pp.631-640
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• 2009

This study aim to identify preference of main and side dishes of 681 children who lived in Seoul and Gyoung-gi (Incheon) in 2007. To accomplish this, we divided the children into three age groups, an infancy group (below 6 years of age), a middle years group (between 7 and 12 years of age) and a juvenile group (above 12 years of age). Specifically, 145 children were in the infancy group (boys 68, girls 77), 300 children were in middle years group (boys 138, girls 162) and 236 children were in juveniles group (boys 131, girls 105). The average body mass index (BMI) of the parents of the respondents appeared to be normal, and the majority of the parents had bachelor degrees. Across all age groups, most fathers were office workers and most mothers were housewives. The preference for staple foods showed that the infancy group and the middle years group preferred rice the most, while the juvenile group preferred stir-fried rice the most out of 5 grain items. Evaluation of the preference for different types of noodles showed that both boys and girls from the infancy group preferred jajangmyun, while those in the middle years group and the juvenile group preferred spaghetti. For breads, both boys and girls from the infancy group had the highest preference for cake, while boys and girls in the middle years group and boys in the juvenile group preferred pizza the most, and girls from juvenile group preferred cake the most. Evaluation of the preference for soups and pot stew revealed that both boys and girls in the infancy group preferred seaweed soup, while boys from middle years group preferred seol-long-tang and girls from middle years group preferred seaweed soup. Boys and girls from the juvenile group preferred seol-long-tang the most. For hard-boiled foods and stir-fried foods, members of all age groups preferred beef boiled in soy sauce the most and hard-boiled peppers the least. Finally, comparison of the preference for roasted foods, seasoned vegetables and kimchi revealed that the infancy group preferred roasted seaweed the most and that both the middle years and juvenile group had the greatest preference for roasted galbi.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.107-107
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• 2005

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.130-136
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• 2004

In the present study, prey preference of juvenile fishes was examined using an experimental approach. Zooplankton composition, as a prey of the fish, was evaluated by taking into account the species as well as body size of juveniles in the aquarium. The predation of juvenile fishes is known to be an important factor in changes of zooplankton communities. In some previous studies at the regulated Nakdong River, the collapse of large cladcoerans and an increase in the rotifer population by selective predation during spring and summer were observed. This study focused on the predation of juvenile fishes such as Hyporhamphus sajori, Rhinogobius brunneus, and Opsariichtys uncirostris amurensis on zooplankton community structure in mesocosm scale experiments. These fishes selected the cladoceran Moina micrura with highest individual preference value (Manly/Chesson index)among zooplankton prey in the experimental aquarium. When the size-selective prey preferences of the juvenile fish were compared, both small (body size <2 cm) and large (body size >2cm) juveniles of O. uncirostris positively selected M. micrura. In the outdoor experimental tanks, juvenile fishes consumed the cladoceran M. micrura, resulting in an high abundance of the rotifer, Polyarthra spp. The results suggest that juvenile fish predation may play an important role in regulating the zooplankton community structure by reducing the cladoceran density and increase of rotifers in the Nakdong River during spring and summer.

• Development and Reproduction
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• v.4 no.2
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• pp.195-201
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• 2000

Sex differentiation process of the spotted sea bass, Lateolabrax maculatus, was investigated by histological method. The fish samples were collected from just after hatching to 365 days later. The primordial germ cells and genital ridge were appeared separately hanging under air bladder in 30-day larva (total length: 11.7~13.2 mm), and were unified into the undifferentiated gonads in 40-day larva (12.5~14.0 mm). The ovarian differentiation was started in 60-day juvenile (23.6~27.0 mm). The somatic tissues were elongated in tip of both ends of undifferentiated gonad and were fused each other. The complete ovarian cavity was appeared in 80-days juvenile(33.1~42.5 mm). The testicular differentiation was initiated in 70-day juvenile (24.8~31.6 mm). The rudiment of sperm duct was appeared in the center of the undifferentiated gonad. The meiosis of germ cells in the ovary was started in 168-day juvenile (88.0~115.4 mm). In 287-day juvenile (175.1~233.6 mm), the ovary was filled with both of chromatin stage and perinucleolus stage oocytes. The meiosis of male germ cells was started in 245-day juvenile (124.4~168.3 mm). However, the seminiferous tubules of testis were filled with numerous sperm in 365-day juvenile (162.5~253.8 mm). The sex ratio of male and female was 1:1.38. Considering these results, the spotted sea bass was showed differentiated type in sex differentiation and gonochorism in sexuality.