• The Journal of Engineering Geology
• /
• v.31 no.4
• /
• pp.659-669
• /
• 2021

The purpose of this study is to elucidate the relationship between occurrence of natural radioactive materials such as ²³⁸U and ²²²Rn and original mixing ratio of helium isotope of groundwater from various geology, and to suggest the underground aquifer environment from helium original mixing data. 9 groundwater samples were collected from five study areas, and ²³⁸U, Rn-222 and helium isotope were analyzed. A high ²³⁸U content of the range of 218~477 ㎍ /L in the groundwater occurs in the twomica granite. ⁴He air-crust mixing ratio and the Rn-222 content show a rough relation, that is, Rn-222 content increases according to the increase of ⁴He crust mixing ratio. Because of helium and radon are an inert gas, their behavior in underground environment is assumed as an analogous. The ²³⁸U content and He isotope in groundwater does not show any distinct correlation. The groundwater can be classified as three groups (air, air-crust mixing, crust-mantle mixing origin) on the diagram of ³He/⁴He vs ⁴He/²⁰Ne, which is composed of original mixing line from air-crust-mantle end members. This original mixing of helium can provide the information of underground aquifer characteristic such as the connection with surface environment or isolation condition from air environment.

• Journal of Environmental Impact Assessment
• /
• v.31 no.6
• /
• pp.388-408
• /
• 2022

This study was conducted to select the indicator species (plant) according to the topographical characteristics in the Picea jezoensis forests, endangered subalpine coniferous trees. In South Korea and China (close to Baekdusan), the southern tree line limit of Picea jezoensis has meaningful geographical and latitudinal values for analyzing the ecological characteristics of P. jezoensis forests. Latitude greatly affects the geographical values of plant ecology, and the difference in latitude and habitat affects the change in species composition in forests. With prolonged environmental change, the habitat of subalpine plants will become smaller, and the plants may become extinct. As the P. jezoensis forests of South Korea and China, in particular, are in danger of disappearing without protection, it is important to monitor the population and develop a conservation strategy. Eighty-seven circular plots were established in P. jezoensis forests in South Korea and China. Through processes such as MRPP-test and NMS ordination, indicator species were selected based on this, and basic data for biodiversity assessment were presented. As a result of the Indicator Species Analysis (ISA), 5 taxa were selected from the upperstory vegetation and 18 taxa from the understory vegetation at the altitude(p<0.05). Indicator species by aspect were analyzed as 3 taxa for upperstory vegetation and 16 taxa for understory vegetation (p<0.05). In the case of indicator species according to the slope, 6 taxa for upper vegetation and 24 taxa for understory vegetation were selected(p<0.05). As for the indicator species according to their habitat, 8 taxa in upper vegetation and 65 taxa on understory vegetation were selected. As a result of MRPP-test, it was analyzed that the species composition was heterogeneous in the group of understory vegetation than that of upperstory vegetation. As a result of NMS ordination, the correlation with environmental factors of indicator species was analyzed by rock exposure for upperstory vegetation and latitude for understory vegetation (cut off level=0.3).

• Sleep Medicine and Psychophysiology
• /
• v.28 no.2
• /
• pp.70-77
• /
• 2021

Objectives: Our study aims to investigate the clinical and polysomnographic variables associated with subjective sleep perception. Methods: Among the patients who underwent nocturnal polysomnography (PSG) at the Center for Sleep and Chronobiology of Seoul National University Hospital from May 2018 to July 2019, 109 diagnosed with insomnia disorder based on DSM-5 were recruited for the study, and their medical records were retrospectively analyzed. Self-report questionnaires about clinical characteristics including Pittsburgh sleep quality index (PSQI), Beck depression inventory (BDI), and Epworth sleepiness scale (ESS) were completed. Subjective sleep quality was measured using variables of subjective total sleep time (subjective TST), subjective sleep onset latency (subjective SOL), subjective number of awakenings, morning feeling after awakening, and sleep discrepancy (subjective TST-objective TST) the morning after PSG. Pearson and Spearman correlation analyses were used to determine the factors associated with subjective sleep perception. Results: In patients with insomnia, subjective TST was negatively correlated with Wake After Sleep Onset (WASO) (p = 0.001) and N1 sleep (p = 0.039) parameters on polysomnography. Also, it was negatively correlated with PSQI (p < 0.001) and BDI (p = 0.014) scores. Sleep discrepancy was negatively correlated with PSQI score (p = 0.018). Morning feeling was negatively correlated with PSQI (p = 0.019) and BDI (p < 0.001) scores. Conclusion: Our results demonstrated that subjective sleep perception is associated with PSG variables (WASO and N1 sleep) and with PSQI and BDI scores. In clinical practice, it is helpful to assess and manage insomnia patients in consideration of objective sleep variables, subjective sleep quality, and depressed mood, which can influence subjective sleep perception.

• Korean Journal of School Psychology
• /
• v.17 no.1
• /
• pp.65-86
• /
• 2020

The purpose of this study was to examine whether self-differentiation mediates the relationship between adolescents' family functioning and self-esteem and to examine whether peer support and family conflicts had moderated mediating effects. For this purpose, 522 students from four high schools in Gyeonggi province were surveyed about their family functioning, self-differentiation, self-esteem, and peer support. The results were analyzed using SPSS 21.0 and PROCESS. The mediating, modulating, and moderated mediating effects were analyzed. The results of this study were as follows. First, correlation analysis showed that family functioning, self-differentiation, self-esteem, and peer support were significantly positively correlated. Second, the moderated mediating effects of peer support were as follows. First, self-differentiation had a partial mediating effect in the relationship between family functioning and self-esteem such that family functioning and self-differentiation were positively correlated and self-differentiation and self-esteem were positively correlated. Second, peer support had a moderating effect in the relationship between family functioning and self-differentiation that promoted self-differentiation. Thus, peer support affected family functioning and self-differentiation. Third, verifying the moderated mediating model of peer support by combining the mediation model of self-differentiation and the moderation model of peer support identified above showed that self-differentiation mediated the relationship between family functioning and self-esteem. Thus, family support affected self-differentiation and self-differentiation affected self-esteem. The significance of this study was as follows. First, it showed that self-differentiation significantly mediated the relationship between family functioning and self-esteem, clarifying the relationship between family functioning and self-esteem. Second, it showed that peer support moderated the relationship between family functioning and self-differentiation, identifying a mechanism that promotes self-differentiation. Third, it showed the mediation of self-differentiation of the relationship between family functioning and self-esteem depended on peer support.

• Korean Journal of Culture and Social Issue
• /
• v.28 no.2
• /
• pp.219-239
• /
• 2022

The study investigated the relationship between subjective socioeconomic status (SES) of 508 Korean adults and their perception of justice (distributive and procedural justice for self and general others), and verified whether there is a moderating effect of age (20s versus 30s and over). A self-report survey on SES and perception of justice was conducted. Then, using the SPSS 27 and PROCESS Macro 4.0 program, a correlation analysis looking into the relationship among the study variables was performed along with the ANOVAs comparing the mean differences of study across age-groups to support the group division criteria. Next, a moderation analysis was conducted. The main results of this study are as follows. First, the participants' SES showed a positive relationship with all sub-factors of justice perception and a negative relationship with age. Second, age had a inverse relationship on distributive justice for self and general others, and procedural justice for self, but a non significant relationship on procedural justice for general others. Third, when looking into the mean differences of the research variables according to age, the 20s had different characteristics compared to the 30s and over. In comparison, there were no significant differences within the 30s and over group. Fourth, the moderating effect of age in the relationship between subjective SES and perception of justice was positively significant in the case of distributive justice for self and procedural justice for general others. In the case of distributive justice for self, the positive slope of the graph in which subjective SES predicts distributive fairness for self was steeper in the 30s and older group compared to the 20s. Regarding the procedural justice for general others, subjective SES was not a significant predictor in the 20s group. However, SES positively predicted procedural justice in the 30s and older group. This study is meaningful since it suggested age differences in subjective SES and perceptions of justice by revealing the different relationship patterns of subjective SES and perception of justice according to age.

• Korean Journal of Mineralogy and Petrology
• /
• v.34 no.4
• /
• pp.241-253
• /
• 2021

Manganese nodules have been found in the shallow water depth of the Arctic Ocean as well as in the abyssal plains of the Pacific and Indian Oceans, but detailed study for them were rarely investigated. Manganese nodules, collected from the East Siberian Sea through the Arctic Expedition using Araon ice braking vessel, have a high potential for Mn mineral resources because they have high Mn content with high Mn/Fe ratio. This study investigated the external form, size and weight, internal texture for the non-spherical manganese nodule, which has about 7 % of total nodule from the East Siberian Sea. This study also researched the relative Mn-oxide mineral composition using the peak area ratio of X-ray diffraction pattern and their chemical composition. All data obtained from non-spherical nodules were compared with the spherical ones. Ellipsoidal, platy and irregular types are common among 5 groups of non-spherical manganese nodule based on the external form, and major axis and weight have positive relationship. All non-spherical manganese nodules have core mainly composed of mud sediments. The average Mn oxide mineral contents in nodules are birnessite, buserite and todorokite in descending order. Although mineral composition does not show any correlation with the external form, kind of core or internal structure, todorokite and buserite contents tend to increase and birnessite content decrease from the surface to the core in the nodule. Non-spherical manganese nodules have higher Mn content and Mn/Fe ratio than those from the shallow water depth of the Arctic Sea and even in the deep-sea of the Pacific and Indian Ocean. Although non-spherical nodule is larger and heavier, and has lower Mn content and Mn/Fe ratio than spherical nodule, there are not any differences in mineral composition and internal structure between them. Almost all manganese nodules collected from the East Siberian Sea are attributed to diagenetic process, because they are higher than 5 in Mn/Fe ratio.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.1
• /
• pp.1-10
• /
• 1984

The main objective of this experiment was to investigate the selection efficiency for clear rice by the application of the wx-carrier technique in rice. Twelve semi-dwarf waxy lines were bred through backcrosses to the two recurrent semi-dwarf parents, IR667 and IR1317, utilizing six different waxy cultivars as waxy donor parent. These waxy lines were crossed to three clear non-waxy varieties, IR24, Suweon 287 and Suweon294. Their F$_3$ seeds were separated into waxy and non-waxy and the clearness of non-waxy grains were counted. The results are summarized as follows: l. Mean clearness per plant for twelve waxy lines ranged from 3.7% to 78.9% at the 35 days after heading. It was higher in the lines which utilized IR 1317 as recurrent parent and it was lower in the lines which utilized IR667 as recurrent parent. Mean clearness per plant for recurrent parent, IRl317 and IR667 were 47.6% and 5.6% respectively. The clear non-waxy parents; Suweon287, IR24 and Suweon294 showed 83.7% 80.5% and 73.5% clearness respectively. 2. Mean clearness of F$_3$ seeds of the crosses between different waxy parents and IR24, Suweon 294 and Suweon 287 ranged 16.7-73.9%, 21.9-42.9% and 10.6-26.9%, respectively. IR24 crosses showed the highest mean clearness. 3. Highly positive correlation was found between the clearness of F$_3$ seeds of Suweon 287 crosses and those of Suweon294. 4. Significant differences were observed in mean clearness of F$_3$ seeds of the crosses between the different waxy lines, which was bred through the same number of backcrosses to the same recurrent parent, and a clear non-waxy parent. Crosses of IR1317 recurrent parent showed higher mean clearness than those of IR667 recurrent parent. 5. In some crosses, clearness was higher in homo-non-waxy than in hetero-non-waxy, but, in other crosses it was higher in hetero-non-waxy. Thus no distinct pattern in the segregation of clearness was observed along the homo-non-waxy or hetero-non-waxy. 6. From the results it was concluded that, the selection efficiency for the clear rice can be improved by choosing the proper waxy parent, as well as proper recurrent parent under the wx-carrier technique.

• Journal of Korean Society of Forest Science
• /
• v.112 no.3
• /
• pp.280-289
• /
• 2023

Diverse native tree species are distributed in Korean forests; however, information on their regeneration strategies is limited. This study analyzed seed rain from 2011 to 2013, seedling emergence, seedling survival, lifespan distribution, and the relationship between seedling mortality and herbaceous vegetation for 3 years, from 2012 to 2014, to understand the natural regeneration and early survival characteristics of Fraxinus rhynchophylla Hance in natural broad-leaved forests. Seed rain and emerged seedling density significantly differed among the years (p < .05). An increase in seed rain was followed by an increase in seedling emergence in the following year. Seed rain in 2013 and seedling emergence in 2014 showed a significant correlation (p < .05), confirming the trait of F. rhynchophylla seeds that germinate in the following year after seed production. Seedlings emerged in late spring and early summer. Of the seedlings, 78% emerged in the early summer of 2014. Most seedlings died immediately after emergence. Of the seedlings that emerged in August 2012, 56% died within 2 months, and 38% of those that emerged in July 2014 died within 1 month. Shade and competition against ground vegetation chiefly affected the seedling survival of F. rhynchophylla. Fraxinus rhynchophylla showed mast seeding, with a large number of seed production in a particular year. A surge of seedling emergence followed in the early summer of the next year. However, most seedlings died in the same year of emergence. Fraxinus rhynchophylla has a high seedling mortality, but mast seeding and the resulting high seedling emergence produce a few survived seedlings, enabling the continuation of the F. rhynchophylla population. Efforts and research on the natural regeneration of native tree species are required to effectively manage natural forests in Korea.

• Analytical Science and Technology
• /
• v.20 no.3
• /
• pp.227-236
• /
• 2007

This study was carried out to estimate the contents of heavy metals (Hg, Pb, and Cd) in seaweeds (n=169) which are closely related to food resources. The contents of heavy metals in the laver were found as follows; Hg was highly detected in the east coastal area ($0.0509{\pm}0.0635mg/kg$), Pb in the south coastal area ($0.0509{\pm}0.0635mg/kg$), Cd in the south coastal area ($1.3785{\pm}0.7754mg/kg$). In the sea mustard, Hg was highly detected in the south coastal area ($0.0152{\pm}0.0116mg/kg$), Pb in the east coastal area ($0.1633{\pm}0.2888mg/kg$), Cd in the south coastal area ($0.7141{\pm}0.4952mg/kg$). In the sea tangle, Hg was highly detected in the south coastal area ($0.0177{\pm}0.0118mg/kg$), Pb in the east coastal area ($0.0728{\pm}0.1025mg/kg$), Cd in the south coastal area ($0.1640{\pm}0.1253mg/kg$). In the sea lettuce, Hg, Pb, and Cd were highly detected from the west coastal area. In the fusiforme, Hg and Cd were highly in the west coastal area, Pb in the south coastal area. In general brown algae showed the highest level of Hg, Pb, and green algae showed the highest level of Cd Additionally, the significant correlation was observed between Hg and Cd (r=0.513, p<0.01), between Cd and Pb (r=0.420, p<0.05). The weekly average intakes of Hg, Pb and Cd from seaweeds takes about 0.17~10.30 % of PTWI (Provisional Tolerable Weekly Intakes) that FAO/WHO Joint Food Additive and Contaminants Committee has set to evaluate their safeties.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.3
• /
• pp.213-220
• /
• 2019

Desire for a happy life becomes the will that man instinctively desires. In that the conditions of happiness are subjective and varied, the will of subjective desires has been studied with the attention of objective tendencies. The positive and meaningful will of life in the desire for happiness leads us to be the functionaries who act. These wills can be the driving force of a happy life, which allows one to have a hopeful reflective will in one's inner life, connecting oneself with others, and working in relationships with others. In addition, those who become lazy or lose their orientation in life can instill a will to be the main character of life, and furthermore, to give the ultimate meaning and goals of life. To understand and analyze these wills for happy lives more specifically, structural model compatibility and confirmatory factors were conducted. relatively reliable α=.855 value, the coefficient of correlation between recognition and will **p<.01, *p<.05 statistically significant measuring tool of not less than 05 was used. The study results of the structural model suitability of the factors of will and the confirmatory factor analysis showed that the model set by the researcher could reflect the characteristics of the data collected, and that the χ²(Chi-square) value was .126, which was consistent with the model by satisfying the acceptance criteria, and that the comparison of the reference values of the study model showed a relatively high level of suitability. To identify the relationship between cognitive and defined and behavioral factors of subjective will and existent will variables, the results of a verification factor analysis show that the χ²(Chi-square) value is 2.36 and the model and data are consistent with the acceptance criteria, and that the test data is consistent with the model and data set by the researcher are consistent with the model5.0 Through structural model analysis of human will, it was confirmed that the variables of subjective and existential, sensible and reflective will directly and indirectly influence and form a complex relationship. Our will is recognized as the subjective will, and the structure of the subjective will consists of the sensible and reflective will, and the relationship between the cognitive and just action elements and the subjective will of the human life and the will to exist is shown to be very meaningful, so we should conduct the education of the happy will of the emotional and just areas of life as well as the reestablishment of the cognitive educational direction that can lead to action.