• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.320-329
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• 2023

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg^-1 Cd, 96% at 1.87 mg kg^-1 Cd, and 93% at 6.09 mg kg^-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg^-1, 13.06 mg kg^-1, and 79.11 mg kg^-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg^-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

• Journal of the Korean earth science society
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• v.44 no.6
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• pp.578-593
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• 2023

Intense convective activity and heavy precipitation inundated Seoul and its metropolitan area on July 15, 2017. This study investigated the synoptic-scale meteorological drivers of cold cloud genesis of this event. The WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) model was employed to explore the intricate interplay between meteorological factors and the indirect effects of PM_2.5 aerosols originating from eastern China. The PM_2.5 aerosols' indirect effect was quantified by contrasting outcomes between the comprehensive Aerosol Radiation Interaction experiment (encompassing aerosol radiation feedback, cloud chemistry processes, and wet scavenging in the WRF-Chem model) and ACR (Aerosol Cloud Radiation interaction) experiment. The ACR experiment specifically excluded aerosol radiation feedback while incorporating only cloud chemistry processes and wet scavenging. Results indicated that in the early hours of July 15, 2017, a convergence of warm, moisture-laden airflow originating from southeast China and the East China Sea unfolded over the Yellow Sea. This convergence was driven by the juxtaposition of a low-pressure system over the Chinese mainland and Northwest Pacific high. Notably, at approximately 12 km altitude, the resultant convective clouds were characterized by the presence of ice crystals, a hallmark of continental-origin cold clouds. The WRF-Chem model simulations elucidated the role of PM_2.5 aerosols from eastern China, attributing 5.7, 10.4, and 10.8% to cloud water, ice crystal column, and liquid water column formation, respectively, within the developing cold clouds. Thus, this study presented a meteorological mechanism elucidating the formation of deep convective clouds over the Yellow Sea and the indirect effects of PM_2.5 aerosols originating from eastern China.

• Korean Journal of Culture and Social Issue
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• v.14 no.4
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• pp.19-37
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• 2008

The youth unemployment issue has not shown any improvement in years. The purpose of this study was to observe how employment issues affecting university students influence their life aims, self-efficacy, view of reality, view of the future, and life satisfaction. 239 students from three universities located in Seoul and Gyeonggi province were assessed through the instrument FLL and questions about employment issues, their life aims, life satisfaction and also their employment perspective. A total of 34 items of the FLL were divided through factor analysis into six higher life aims, self-love, family love and interpersonal aims, personal-financial aims, social-public aims, moral aims and political and ideological aims. Using Cluster analysis, three group profiles were found depending on the employment perspective such as a better view of reality, better self-efficacy, and better life satisfaction. A t-test was conducted in order to compare the two groups classified according to favorable or unfavorable employment perspectives. No significant differences existed between the groups in the perception of youth unemployment or in social-demographic factors, such as gender, age, and academic year. However, in life aims, the unfavorable group showed significantly higher interest in the domains of family love and interpersonal aims, personal -financial aims, and social-public aims than the favorable perspective group. Conversely, this group showed a significantly greater negative view of reality in most life domains, as it evaluated that its aims are more poorly achieved than the comparable group. Also, the unfavorable perspective group showed a lesser degree of self-efficacy in most life domains and the same in the category of life satisfaction, i.e., lesser satisfaction in all life domains except for family love, and moral aims. However, no significant difference existed between the groups in the view of the future. The results were discussed in relation to other social-cognitive factors for life satisfaction found in preceding studies.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.589-601
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• 2023

We compare high-resolution seabed bathymetry data and seafloor backscattering data acquired, using multi-beam, between 2018 and 2021 to understand topographic changes in the coastal area of Dokdo. The study area, conducted within a 500 m × 500 m in the southern coast between the islands where Dongdo Port is located, has been greatly affected by human activities, waves and ocean currents. The depth variations exhibit between 5 - 70 m. Irregular underwater rocks are distributed in areas with a depth of 20 m or less and 30 - 40 m. As a whole, water depth ranges similar in the east-west direction and become flatter and deeper. The bathymetry contour in 2020 tends to move south as a whole compared to 2018 and 2019. The south moving of the contours in the survey area indicates that the water depth is shallower than before. Since the area where the change in the depth occurred is mainly formed of sedimentary layers, the change in the coast of Dokdo were mainly caused by the inflow of sediments, due to the influence of wind and waves caused by these typhoons (Maysak and Haishen) in 2020. In the Talus area, which developed on the shallow coast between Dongdo and Seodo, the bathymetry changed in 2020 due to erosion or sedimentation, compared to the bathymetry in 2019 and 2018. It is inferred that the changes in the seabed environment occur as the coastal area is directly affected by the typhoons. Due to the influence of the typhoons with strong southerly winds, there was a large amount of sediment inflow, and the overall tendency of the changes was to be deposited. The contours in 2021 appears to have shifted mainly northward, compared to 2020, meaning the area has eroded more than 2020. In 2020, sediments were mainly moved northward and deposited on the coast of Dokdo by the successive typhoons. On the contrary, the coast of Dokdo was eroded as these sediments moved south again in 2021. Dokdo has been largely affected by the north wind in winter, so sediments mainly move southward. But it is understood that sediments move northward when affected by strong typhoons. Such continuous coastal change monitoring and analysis results will be used as important data for longterm conservation policies in relation to topographical changes in Dokdo.

• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.161-195
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• 2006

The purpose of this study is to examine factors influencing quality of life for individuals in the family, school or workplace, leisure settings, and Korean society using the indigenous psychological analysis. A total of 3,406 participants, consisting of 1,331 elementary, middle, high school students and 2,075 parents and teacher, completed an open-ended questionnaire developed by Kim and Park (2004b). The respondents reported the factors that influence quality of life in Korean society as follows: Economic condition, collective effort, leisure and cultural life, harmonious interpersonal relationships, effective government policy, and educational attainment. The factors that reduce quality of life in Korean society are as follows: Economic uncertainty, political instability, lack of citizenry, ingroup favoritism, corruption, lack of facilities for leisure and social life, and overemphasis on educational achievement. Second, the factors that influence quality of life in the family are as follows: Harmonious family relations and financial security. For students relationship with friends and academic achievement are reported as important factors influencing quality of life at school. For adults, harmonious interpersonal relationship, financial factors and occupational achievement are reported as important factors influencing quality of life at the workplace. For leisure and social leisure life, financial security, leisure time and interpersonal relationships are reported as important factors influencing quality of life. Third, as for generational differences, students reported political instability and adults reported economic uncertainty as the most important factor reducing quality of life in Korean society. For family life, students reported conflicts among family members and adults reported financial constraints as the most important factor reducing quality of life. For leisure and social life, students reported lack of leisure time and adults reported financial constraints as the most important factor reducing quality of life. Fourth, for students the following characteristics were associated with higher quality of life: Higher socio-economic status of the family, younger, and higher academic achievement. For adults, the following characteristics were associated with higher quality of life: Higher socio-economic status of the family and greater achievement their social life. Implications of these results on the quality of life in Korea, focusing on human relationship, financial factors, self-regulation and educational achievement are discussed.

• Korean Journal of Culture and Social Issue
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• v.12 no.5_spc
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• pp.99-116
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• 2006

This paper discuss adolescent's a quality of life related with risk behavior. The purpose of this study investigate to influence on risk behavior(runaway, smoking, sexual behavior) of the protective factors that moderate adolescent's problem behavior(delinquency). The assumption of this study that the protective factors counterbalance the negative influence of risk factors and finally, diminish a the problem behavior including a delinquent. A total of 1,020 students of a vocational high schook and a 216 adolescents of a special groups(the public institution that consisted with a delinquent young man) completed the questionnaires(risk behavior, 5 protective factors) of compiled by this researcher. The protective factors have selected based on the various prior studies analyzed with adolescent's risk behavior a family functioning, a father(a mother) each and child communication, a self efficacy, and a social support. Statistics appled for the data analysis are Chisqure analysis, two-way ANOVA, and Standard Discrimination analysis. The results of this study are as follows. First, the special group is higher than the general group in the rate of runaway, smoking, and sexual deviant behavior. Second, the protective factors are not action in the special group have experienced delinquency, but are only action in the general group consisted with the students of a vocational high schools. This means that the protective factors discriminating the participation of the risk behaviors, and blocking out the intervention of a problem behavior in the general adolescents. Although each protective factor influence to different according to each risk behavior, a role of a parent-child communication, a family functioning, and self-efficacy high orderly. Finally, discussed based on the previous studies that the protective factors moderate the negative influence of risk factors, offset the connection between a risk behavior and a. problem behavior, and improve and a resilience and the quality of life of the adolescents.

• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.129-160
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• 2006

The purposes of this study were to find 1) the realities of social anxiety and perception of various kinds of social problems that exists in Korean society as well as the perception on the events that causes the social anxiety, 2) to see the difference of perceived level of social anxiety through variables of social demography and difference of perception on Korean society. The sample was distributed according to population size distinguishing the nation to 6 regions. The data of 1,375 adult respondents were analysed. The results are as follows. First of all, respondents mentioned that the most immediate problem to be solved in Korean society was financial anxiety, and the most desirable state of society was when the society is financially stabled. Single question was measured about social anxiety of Korean society and scored 6.84 from full marks of 10, showing difference in variables for instance sex, age, and subjective S.E.S. where women, aged under 20, and perceived low class group showed the highest rate of social anxiety. However, there weren't any difference found in social anxiety of the variables like presence of religion, educational background, residence, and monthly average household income. Also, there were differences in level of social anxiety according to the difference of perception of Korean society. Higher the perceived unpredictability, uncontrollability, and unmovability to the upper class, unfairness, and uncertainty, unreliability of the Korean society, higher the social anxiety. And the lower the perceived chance of success of reformation, higher the social anxiety. It was also found that the perceived social anxiety is influenced by social accidents and phenomenon as unemployment, economic depression, and the gap between rich and poor as well as the increase of crime through effluence of personal information. Finally the limitations and implications of this study were discussed.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.2
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• pp.45-57
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• 2023

Objective : The purpose of this study was to investigate the concurrent validity of the self- and proxy-report versions of the KIDSCREEN-10 quality of life questionnaire. Methods : A total of nine children and nine parents were selected to represent a cohort registered for a school-based wellness program. Two versions of the KIDSCREEN-10 questionnaire (self- and proxy reports) were administered to the children and their parents. The Rasch rating scale model was applied to determine the dimensionality and item difficulty of the two versions of the questionnaire. Moreover, the item-person matching map and Spearman's rho were compared to confirm the concurrent validity of the two versions. Results : All items, except four items (i.e., autonomy, home life, concentration/learning, and peers/social support), fit the Rasch rating scale model of the children's self-report version of the questionnaire. With regard to the parent's proxy-report version, two items misfit the model. While the items of the self- and proxy-report versions showed similar item difficulties, the parents had a tendency to be more severe in their ratings than the children. The correlation between the two versions was relatively low (Spearman's rho = .533, p > .05). The scatterplots between the two versions showed differences in the item difficulties of the physical and psychological well-being and self-perception items. Conclusion : These findings suggest that the three identified items should be taken into consideration when measuring children's health-related quality of life using the KIDSCREEN-10 questionnaire.

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.15-23
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• 2023

In a situation where the necessity and importance of ESG management is increasing recently, it is judged that selecting important ESG-related variables for container terminals, which are the bases of export and import logistics, among various variables of ESG evaluation agencies will help to establish ESG management strategies for container terminals which led us to proceed with this study. The results of word network analysis are summarized as follows. The weighed degree, that is, the AWD of Environmental management(E) variables, is obtained in the order of Environmental Protection Investment(54), Environmental Awareness Education(45), Work Team Structure(31), Environmental certification(32). Page Ranks, the order of centrality and connectivity index is Environmental Awareness Education(0.0765), Employee Engagement(0.0765), Environmental Protection Investment(0.0761), Work Team Composition(0.0761), and Environmental certification(0.0761). The AWD(Average Weighed Degree) of the Social Responsibility Management(S) variables, followed by Protecting workers' human rights and contributing to local communities(68), Safety Education(63), Safety certification(59), and Responding to infectious diseases(40). Orders by Page Ranks, centrality and connectivity Index, are Protecting workers' human rights and contributing to local communities(0.165), Safety Education(0.153), Safety Certification(0.144) and Responding to infectious diseases(0.102). The AWD of Governance and Ethical management(G) variables, followed by Anti-corruption(27), Transparent management(24), Mutual cooperation between stakeholders(19), and Sustainability reporting(9). Page Ranks, the order of centrality and connectivity index is the Anti Corruption(0.241), Transparent management(0.216), Mutual cooperation between stakeholders(0.174), Directors' roles and responsibilities(0.105), Shareholder protection(0.097) and Sustainability Report(0.096).

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.257-267
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• 2023

Purpose. The purpose of the study was to fabricate a prototype robotic simulator for dental education, to test whether it could simulate mandibular movements, and to assess the possibility of the stimulator responding to stimuli during dental practice. Materials and methods. A virtual simulator model was developed based on segmentation of the hard tissues using cone-beam computed tomography (CBCT) data. The simulator frame was 3D printed using polylactic acid (PLA) material, and dentiforms and silicone face skin were also inserted. Servo actuators were used to control the movements of the simulator, and the simulator's response to dental stimuli was created by pressure and water level sensors. A water level test was performed to determine the specific threshold of the water level sensor. The mandibular movements and mandibular range of motion of the simulator were tested through computer simulation and the actual model. Results. The prototype robotic simulator consisted of an operational unit, an upper body with an electric device, a head with a temporomandibular joint (TMJ) and dentiforms. The TMJ of the simulator was capable of driving two degrees of freedom, implementing rotational and translational movements. In the water level test, the specific threshold of the water level sensor was 10.35 ml. The mandibular range of motion of the simulator was 50 mm in both computer simulation and the actual model. Conclusion. Although further advancements are still required to improve its efficiency and stability, the upper-body prototype simulator has the potential to be useful in dental practice education.