• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.557-564
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.307-319
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• 2019

This study aims to provide the basic materials for the development of leisure and tourism contents in connection with Osaek cableway for the revitalization of Osaek District. For such a purpose, the following policy directions were presented through the analysis of the present situation and conditions of Osaek District, the direction of development of leisure and tourism contents of Osaek District, etc. The first is increasing the participation of local residents and reinforcing their capabilities. The suggested promotion plans are ① establishing organizational system and strengthening support, ② reinforcing the capabilities of local residents and ③ constructing networks with external human resources. The second is setting the guidelines for contents development. It was proposed to prepare contents for leisure experience using the natural environment of Osaek District in response to the trend of increase of people who enjoy "contents using culture and arts" and leisure. The third is typological approach to contents. It was proposed to develop cultural contents with the theme of Osaek such as "Osaek Light Festival", "Osaek Concert", "Osaek Photo Exhibition" and "Osaek Good Men and Women Contest" for the promotion of the brand of the place name of Osaek and the creation of the "Picture Book Village" for the compilation of the history and culture of Osaek District with pictures. The fourth is securing marketing channels. For this, it was proposed to produce the website of Yangyang County or a website tentatively named as "Osaek-ri with Beautiful Osaek" and introduce an integrated travel product (transportation + lodging + foods + experience (hot spring, mineral water therapy, leisure experience, etc.) + purchasing local specialty products, etc.) composed of the leisure and tourism contents, transportation, lodging, foods, etc. of Osaek District through travel agencies. The final policy direction presented was phased implementation of the development and operation of the contents. Proposed policies include support of a consulting project to upgrade the organization of local residents; implementation of "Tourism Dure (Cooperative)" project for the solution of the problem of tourism in Osaek District by the residents themselves together using the space of culture and arts made by remodeling idle public and private facilities after benchmarking exemplary places; system improvement for the introduction of leisure and tourism contents appropriate for local conditions; and the establishment of a master plan for the introduction of various leisure and tourism contents in Osaek District.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.369-393
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• 2010

This study examines the factors influencing Korean international adoptee's search for their birthparents. Considering that the search for birthparents is general needs for adoptees, Korean government should support their searching activities and, first of all, understand their characteristics. The research model was constructed based on the results of previous studies, and the data set of conducted by ministry of health and welfare was reanalyzed for this study. The subjects of the survey were Korean-born adoptees (who are more than 16 years old) in North America, Europe, and Australia. The research questionnaire was translated to English and French, and the survey was conducted on line. A total of 290 questionnaires were included in the analysis. Since survey was conducted on line, the missing rate of the data was relatively high. So, multiply imputed five data sets were used for analysis. Among the variables included in research model, the age group of adoptees, experience of identity crisis in their life, the first time when they became actively interested in Korean roots, the age at the time of adoption, and the attitudes of adoptive parents toward their search were significantly related to their search for birthparents. Adoptees in the age group of 30~34 had more actively participated in search compared to their reference group (which is the age group of more than 35 years old). The earlier they became actively interested in Korean roots, they tended to be more active in searching activities. Also, the experience of identity crisis in life and the age at the time of adoption were positively related to their search. Although most of adoptive parents have supported their search, the adoptees who reported that they didn't know their adoptive parents' attitude toward search, or their parents deceased had more actively participated in search for their birthparents. Some implications for adoption policy and practice were discussed based on the results of the study.

• Korean Journal of Culture and Social Issue
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• v.18 no.1
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• pp.127-152
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• 2012

The research investigates the attitudes toward children among mothers young children and maternal grandmothers, focusing specifically on the ideal number of children, gender preference, old age security and positive and negative values of children. A total of 442 respondents, consisting of 221 young mothers (average age of 35) and 221 maternal grandmothers (average age of 63) completed a questionnaire developed by Kim, Park and Kwon (2005). The reliability of the scales ranged from Cronbach α of .78 to .91. The results are as follows. First, as for the ideal number of children, young mothers reported that they would prefer two children, while grandmothers reported that they would prefer four children. As for the ideal number of male child, young mothers reported that they would prefer that they would prefer one son, while grandmothers reported two sons. Second, as for the gender of the child, young mothers did not show a gender preference, while grandmothers stated that at least one child should be a son, especially if it is the only child. Third, grandmothers had higher expectation of old age security in their male child than young mothers but two groups did not show any difference for the female child. Fourth, as for positive values of children, young mothers were more likely to emphasize personal aspects (i.e., psychological pleasure and happiness) and family cohesiveness, while grandmothers were more likely to emphasize social aspects (i.e., continuing the family line and old age security. As for negative values of children, young mothers were more likely to emphasize personal aspects (i.e., parental role and responsibility), while grandmothers were more likely to emphasize social aspects (i.e., family conflict and relationship). Fifth, as for factors that influenced the number of children that they decided to have, young mothers were more likely to report negative values of children (i.e., financial constraints), while grandmothers were more likely to emphasize positive values of children (i.e., continuing the family line).

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.427-435
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• 2023

Changes in flowering time due to weather fluctuations impact plant growth and ecosystem dynamics. Accurate prediction of flowering timing is crucial for effective forest ecosystem management. This study uses a process-based model to predict flowering timing in 2023 for five major tree species in Korean forests. Models are developed based on nine years (2009-2017) of flowering data for Abeliophyllum distichum, Robinia pseudoacacia, Rhododendron schlippenbachii, Rhododendron yedoense f. poukhanense, and Sorbus commixta, distributed across 28 regions in the country, including mountains. Weather data from the Automatic Mountain Meteorology Observation System (AMOS) and the Korea Meteorological Administration (KMA) are utilized as inputs for the models. The Single Triangle Degree Days (STDD) and Growing Degree Days (GDD) models, known for their superior performance, are employed to predict flowering dates. Daily temperature readings at a 1 km spatial resolution are obtained by merging AMOS and KMA data. To improve prediction accuracy nationwide, random forest machine learning is used to generate region-specific correction coefficients. Applying these coefficients results in minimal prediction errors, particularly for Abeliophyllum distichum, Robinia pseudoacacia, and Rhododendron schlippenbachii, with root mean square errors (RMSEs) of 1.2, 0.6, and 1.2 days, respectively. Model performance is evaluated using ten random sampling tests per species, selecting the model with the highest R². The models with applied correction coefficients achieve R² values ranging from 0.07 to 0.7, except for Sorbus commixta, and exhibit a final explanatory power of 0.75-0.9. This study provides valuable insights into seasonal changes in plant phenology, aiding in identifying honey harvesting seasons affected by abnormal weather conditions, such as those of Robinia pseudoacacia. Detailed information on flowering timing for various plant species and regions enhances understanding of the climate-plant phenology relationship.

• Korean Journal of Culture and Social Issue
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• v.16 no.3
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• pp.385-422
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• 2010

This study examines adolescent delinquent behavior and the influence of friends, focusing specifically on friends' delinquent behavior and the influence of self-efficacy, parent-child conflict and parental control. A total of 1,399 adolescents attending five different high schools (male=642, female=756, consisting of 915 student attending high school and 484 students attending vocational high school) completed a questionnaire developed by Ahn, Hwang, Kim and Park (1997) and Bandura's (1995a) self-efficacy scale. Results indicate that those students who attend high school had parents with higher education, socio-economic status and better studying environment at home, while students attending vocational high school had higher parent-child conflict. Students attending high school had higher self-efficacy scores, while students attending vocational high school had higher scores on delinquent behavior. The results of LISREL analyses revealed a similar pattern for high school and vocational high school students. Combined analysis indicate that friends' delinquent behavior, parent-child conflict and parental control had direct and positive effect on students' delinquency behavior. Self-efficacy had a direct and negative influence of delinquency behavior. Similar pattern was obtained for friends' delinquency behavior, in which self-efficacy had a direct and negative influence of their delinquency behavior and their parent-child conflict and parental control had direct and positive effect on their delinquency behavior. In summary, those students who had lower self-efficacy, higher parent-child conflict and parental control, and with friends who are more likely to engage in delinquent behavior, had higher scores on delinquent behavior. Also, those students who had friends with lower self-efficacy scores and with higher parent-child conflict and parental control are more likely to engage in delinquent behavior, which in turn influenced their delinquent behavior. Friends' delinquent behavior had the greatest influence on students' delinquent behavior indicating the role of friends in influencing delinquency among adolescents.

• 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.11 no.2
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• pp.143-181
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• 2005

This article examines factors that influence health and quality of life. In addition to the symptomatology and physiological functioning, the influence of the psychological functioning and interpersonal relationship on the overall health and quality of life are also investigated. Using a case-study approach, a total of 70 patients suffering from allergy or asthma were interviewed using a semi-structured questionnaire developed by the present authors. It assessed the following six areas: Cause and onset of illness, psychological functioning, health management, trust, social support received and overall health and quality of life. Based on the transactional model (Bandura, 1997; Kim & Park, 2005), the results of the case studies have been integrated and divided into three aspects: (1) Cause and onset of illness that includes physiological and environment factors; (2) mediating influences that includes psychological functioning, health management, interpersonal relationship and social support received; and (3) outcome factor that includes symptomatology, health and quality of life. The psychological functioning includes self-efficacy (self-regulated efficacy, efficacy for enlisting social support, efficacy for managing the environment, and efficacy for overcoming difficulties), positive outlook, life goals, experience of stress, and proxy control. Interpersonal relationship includes trust of family members and the physician. Health management includes receiving proper health assessment, following the advice and prescription given by the physicians, control of the environment and maintaining a healthy lifestyle. The results indicate that physiological, psychological, relational and environment factors interact with each other and affect individual's overall health and quality of life. Self-efficacy, social support received from family members, trust of physicians, and the health care system are key factors promoting healthy lifestyle and quality of life. The results indicate the need for further interdisciplinary, indigenous and cultural psychological research.

• Korean Journal of Culture and Social Issue
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• v.10 no.3
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• pp.103-129
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• 2004

This article examines the Korean adolescents and adults' social representation and trust of Korean society and people using indigenous psychological analysis. Respondents were asked to write in an open-ended questionnaire their perception of the following five aspects: Korean politics, economy, society, culture and people. They were then asked to report why they trust or distrust Korean society. A total of 1,064 respondents (218 middle school students, 200 university students, 218 fathers of the middle school students, 218 mothers of the middle school students, and 210 teachers) completed a questionnaire developed by the present researchers. The data were collected during April to June, 2003. The results indicate that 94.5% of Koreans view the existing political system and politicians as being corrupt, inept, factional, and lacking in integrity. A vast majority (84.9%) recognize the existence of systemic problems in the Korean economy. A total of 78.2% see problems in Korean society being dominated by selfishness, factionalism, conservatism, and social uncertainty. For Korean culture, a majority of respondents report being proud of its cultural tradition, accomplishment, and creativity. At the same time, 45.7% report loss of cultural identity and pride due to external influences. More than half of the respondents report negative aspects of Korean people (i.e., selfish, lack of morality, rushed, and overly focused on their social image), while nearly half of the respondents report positive aspects of Korean people as being compassionate, cooperative, good-natured and hard-working. As for reason for trusting Korean society, around a third report "because it is our country," followed by its future potential, and the good-nature and willingness of Korean people to work hard. The reasons for distrusting Korean society is the dishonesty politicians, corruption, institutional ineptness, and economic uncertainty. These results indicate a low level of collective efficacy in influencing and affecting change in Korean society.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.195-203
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• 2023

Purpose: This study aimed to evaluate the influence of surface sealants on the surface roughness of composite resins. Materials and Methods: The study used microfilled composite resin (Metafil CX, Sun Medical Co.) and hybrid composite resin (Aelite^TM LS posterior, Bisco). Sixty specimens (8 mm in diameter and 4 mm in height) of each composite resin type were prepared and divided into 3 groups. Each specimen was ground with 600, 1000, and 2000-grit sandpaper. The Surface roughness (Ra) values were measured using a surface roughness tester (SJ-301, Mytutoyo) before and after surface sealant application. Surface sealants, BisCover^TM LV (Bisco), Optiguard^® (Kerr), and Seal-n-Shine^TM (Pulpdent), were applied to the specimens, as instructed and observed by scanning electron microscope (JSM-7500, JEOL) and atomic force microscope (MultiMode IV, Veeco Instruments). Results: Specimens ground with 600-grit sandpaper coated with surface sealants exhibited significantly lower Ra values than the untreated group (P < 0.05). Specimens ground with 1000 and 2000-grit sandpaper showed statistically no difference. There was no significant difference in surface roughness among BisCover^TM LV, Optiguard^®, and Seal-n-Shine^TM. SEM and AFM revealed remarkably decreased microdefects on the surfaces of composite resins after surface sealant application. Conclusion: Surface sealants can influence surface roughness when applied on the rough surface of composite resins but not on highly polished composite resins.