• The Korean Journal of Malacology
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• v.29 no.4
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• pp.313-323
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• 2013

Gonad development, the reproductive cycle, first sexual maturty and size at 50% of group sexual maturity (the biological minimum size) of Gomphina (Macridiscus) veneriformis were investigated for clams collected from the coastal waters of Donghae City, the East Sea of Korea by histological, and morphometric analysis. Monthly variations of the gonad index showed a pattern similar to that of the reproductive cycle. The reproductive cycle with the gonad developmental stages in female and male G. (M.) veneriformis can be classified into five successive stages: early active stage (December to March), late active stage (March to June), ripe stage (June to July), partially spawned stage (June to August), and spent / inactive stage (September to December). The spawning period continued from June to August, with a peak between July and August when the seawater temperature exceeds $20^{\circ}C$. The percentages of first sexual maturities of female and male clams ranging from 25.1 to 30.0 mm were 56.3% in females and 61.1% in males, and for clams over 30.1 mm shell length, it was 100%. Shell lengths at 50% of group sexual maturity (biological minimum size, $RM_{50}$) were 27.71 mm in females and 26.31 mm in males. Because harvesting clams < 26.31 mm in shell length could potentially cause a drastic reduction in recruitment, a measure indicating a prohibitory fishing size should be taken for adequate fisheries management.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.339-349
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• 2014

The purpose of this study is to find out the effects of career education program using a career camp on elementary school students' career maturity, career self-efficacy, and career barriers. This study was conducted on 50 elementary school students in Busan, who are divided into two groups; one is an experimental group of 25 students and the other is a control group. The result is analyzed by Analysis of Covariance(ANCOVA) for the career maturity, career self-efficacy, and career barriers. The conclusions are as follows: First, the experimental group participated in the career education program using a career camp showed higher level in career maturity as a whole opposed to the control group. Second, the experimental group participated in the career education program using a career camp showed higher level in career self-efficacy. Third, the experimental group participated in the career education program using a career camp showed lower level in career barriers as a whole opposed to the control group. Thus, the results of this study show the importance of developing a model for career education program using a career camp of department of education.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.255-263
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• 2014

We investigated the reproductive characteristics of Lycodes tanakae in the coastal waters of the middle East Sea to elucidate the species' population structure. We investigated Lycodes tanakae maturation and spawning based on samples collected by Danish seine and gill nets from January 2012 to December 2013. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. The spawning period was December to February, while fecundity ranged from 1,677 eggs at 57.3 cm (total length;TL) to 6,445 eggs at 75.7 cm. The relationship between TL and fecundity (F) was $F_e=6E-05TL^{3.127}$ ($R^2$ = 0.516), and F increased with increasing TL. We estimated the TL at 50% group maturity as 60.4 cm for females and 59.8 cm for males. This study is the first report of Lycodes tanakae reproductive characteristics in the coastal waters of the middle East Sea.

• 대한공업교육학회지
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• v.37 no.1
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• pp.21-41
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• 2012

The objective of this study was to examine the relation between delinquency and career maturity in school adolescents and to determine whether activities for enhancing career maturity can have protective effects against juvenile delinquencies. Research questions for this study are: first, how serious school adolescents' delinquencies are; and second, what relation there is between delinquency and career maturity in school adolescents. Third, how different is school adolescents' career maturity according to their experience in delinquencies? The results of this study were as follows. First, 55.8% of the school adolescents committed one or more of the 14 types of delinquent acts included in the delinquency inventory during the last one year, and the percentage was higher among male students than among female ones. Second, no correlation was observed between the school adolescents' overall delinquency level and overall career maturity. According to the sub-factors of career maturity, however, the overall delinquency level was in a negative correlation with objectiveness and a positive correlation with independence/decisiveness. That is, objectiveness was higher in the group without experiences in delinquencies than in the group with such experiences. and Type II status offenses (truancy, runaway) was in a negative correlation with overall career maturity, and in a negative correlation with objectiveness and confidence. Third, no significant difference was observed in career maturity between those with experience in delinquencies and those without. Among the sub-factors of career maturity, however, objectiveness was higher in those without experience in delinquencies than in those with. and Overall career maturity, and objectiveness and confidence among the sub-factors of career maturity were significantly higher in those without experience in Type II (truancy, runaway) status offenses than those with. The results of this study suggest that the objectiveness of career maturity can be a protective factor against juvenile delinquency. Furthermore, they suggest that activities for enhancing career maturity may protect adolescents from Type II status offenses. These results may provide basic materials necessary to develop career counseling approaches and interventions strategies for preventing school adolescents' delinquencies.

• Human Ecology Research
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• v.54 no.2
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• pp.197-206
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• 2016

This study investigates the effect of parental attachment on job seeking stress among the university students and junior college students. We explore the mediating effects of self-efficacy and career maturity on the relations between parental attachment and job seeking stress. We selected 292 university students and 285 junior college students as participants from Daegu and Gyeongsangbuk-do. All participants completed surveys on the measurement of parental attachment, self-efficacy, career maturity, and job seeking stress. Collected data was analyzed by descriptive statistics, Pearson's correlation, structural equational models, and Sobel test with SPSS software ver. 18.0 and Amos software ver. 18.0. The major findings are as follow. First, parental attachment had no significant effect on job seeking stress. Second, self-efficacy and career maturity mediated between parental attachment and job seeking stress. In addition, there were significant differences between university students and junior college students regarding the relation between parental attachment and job seeking stress. Junior college student's career maturity had a greater influence than that of the university students. The findings of this study suggest that intervention to address self-efficacy and career maturity are important to resolve college students' job seeking stress; in addition, school type should be considered to understand job seeking stress.

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.83-89
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• 2010

We studied the maturity and spawning of Marbled sole Pleuronectes yokohamae from May 2006 to April 2007 in the Southern Sea of Korea. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), egg diameters, fecundity (F), total length (TL) at 50% group maturity, and sex ratio. The spawning period was November to February, and the main spawning period was December to January. The fecundity ranged from 75,155 eggs at 17.8 cm(TL) to 1,307,195 eggs at 36 cm (TL), and the relationship between TL and F was $F=3.656TL^{3.518}$ ($R^2$=0.872). The TL at first maturity was 17.8 cm and at 100% maturity, 32 cm. Thus, TL at 50% group maturity was estimated to be 19.8 cm. For sex ratio by length class, males were slightly predominant at sizes under 25 cm TL, but females were 100% at greater than 32 cm TL.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.363-367
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• 2006

The maturity and spawning of brown sole, Pleuronectes herzensteini were investigated using samples randomly collected in the East Sea of Korea from April, 2003 to March, 2004. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), egg diameter, fecundity (F), total length (TL) at 50% group maturity, and sex ratio. The spawning period was February to May, and the main spawning period was March to April. The fecundity was 38,702 eggs at 22 cm (TL) to 133,085 eggs at 37 cm (TL), and the relationship between TL and F was $F=11.307TL^{2.628}$. The TL at first maturity was 15 cm and at 100% maturity, 21 cm. Thus, TL at 50% group maturity was estimated to be 17.8 cm, which corrensponded to the age of 3 years. The sex ratio was 60.2 for female and 39.8 for male, where the female population was seen to be slightly predominant.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.363-375
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• 2012

The gametogenic cycle, the number of spawning seasons per year and first sexual maturiity of the pen shell, Atrina (Servatrina) pectinata, were investigated by quantitative statistical analysis using an Image Analyzer System. Compared two previous results (the spawning periods in the reproductive cycles in 1998 and 2006) by qualitative histological analysis with the present results by quantitative statistical analysis, there are some differences in the spawning periods: the spawning period (June to September) by quantitative statistical analysis was one month longer than those of two previous reports (June to July or June to August) by qualitative histological analysis. However, the number of spawning seasons studied by the qualitative and quatitative analyses occurred once per year. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by follicles to the ovary area in females (or that of the areas occupied by spermatogenic stages to the testis area in males) showed a maximum in May, and then sharply droped from June to September, 2006. From these data, it is apparent that the spawning season of A. (S.) pectinata occurred once a year from June to September, indicating a unimodal gametogenic cycle during the year. Shell heights of sexually mature pen shells (size at 50% of group sexual maturity, $GM_{50}$) that were fitted to an exponential equation were 15.81 cm in females and 15.72 cm in males (considered to be one year old).

• Human Ecology Research
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• v.60 no.4
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• pp.577-593
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• 2022

The purpose of this study is to investigate a student's career maturity during a career exploration program based on the ecological system perspective and to propose directions for the career maturation process to help H. Meister High School students to get jobs. A single-case 12-session career exploration program was applied to a first-year student at H. Meister High School in U. City for 90 minutes per session twice a week. To verify the effects of the program, this study conducted a pre-test and post-test of career maturity to analyze changes. In addition, the study qualitatively analyzed changes in the program activity sheets and process evaluation sheets per session. The results of the study are as follows: Firstly, the career exploration program based on the ecological system perspective conducted with the student at H. Meister High School improved the student's career maturity. Secondly, changes were observed in the scores in the sub-factors of career maturity between the pre-test and the post-test. Significant differences in the results of the analysis of the sub-factors of career maturity indicate that the program had a statistically positive impact on the career maturation process of the participant. In conclusion, as a result of the in-depth implementation of the program for 12 sessions, the participant expressed his desires which were clarified. In addition, a positive career maturation process appears to have taken place, owing to the self-directed program that led the participant to initiate plans and explore his career by himself. This study was conducted as a single case based on the ecological system perspective concerning career exploration and the career maturation process, but it will be necessary to expand the study to investigate the effects of group counseling, information exchange considering peer influences, common discussions on goal-setting, and other methods on the career maturation process.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.17-32
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• 1986

To obtain basic information needed for developing better pearl barley varieties, a total of 148 lines of pearl barley were collected from nationwide survey except for Kangwon and Chejoo provinces and classified by principal component analysis. The results are summarized as follows : 1. Variabilities of characters for all lines except for leaf width and 100 K. Wt.(Unpolished) were high enough to indicate variation of lines. 2. Correlation coefficients among 18 characters were high enough and they showed the shape of normal distribution, more or less, inclined toward positive values. 3. The lines could be classified into four groups by correlation coefficient for 18 characters : Group I was characterized as the lines composed of grain and plant type, Group II maturity, Group III the number of tillers, and Group IV the nature of germination, respectively. 4. About 60% of the total variation could be appreciated by the first four principal components and about 89% of the total variation by the first ten principal components. 5. Contribution of characters to principal components was variable and was high at upper principal components and low at lower principal components. 6. The value of eigen vector corresponding to those which had high significant correlation coefficient between characters was almost of the same value. 7. The lines were classified into four groups by principal component analysis. 8. The lines were also classified into four groups by taxonomic distance. Group I included 79 lines, Group II 40 lines, Group III 22 lines, and Group IV 7 lines, respectively. 9. Four groups classified by taxonomic distance could be characterized as follow : Group I : medium height plant, small kernels, medium maturity, and narrow and short leaf, Group II : short height plant, small kernels, early maturity, and narrow and short leaf. Group III : tall height plant, large kernels, late maturity, and broad and long leaf. Group IV : short height plant, large kernels, medium maturity, and narrow and short leaf.