• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.553-581
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• 2022

Shortly after tunnel boring machine (TBM) was introduced in the tunneling industry, the use of TBM has surprisingly increased worldwide due to its performance together with the benefit of being safely and environmentally friendly. One of the main cost items in the TBM tunneling in rock and soil is changing damaged or worn cutters. It is because that the cutter change is a time-consuming and costly activity that can significantly reduce the TBM utilization and advance rate and has a major effect on the total time and cost of TBM tunneling projects. Therefore, the importance of accurately evaluating the cutter life can never be overemphasized. However, the prediction of cutter wear in soil, rock including mixed face is very complex and not yet fully clarified, subsequently keeping engineers busy around the world. Various prediction models for cutter wear have been developed and introduced, but these models almost usually produce highly variable results due to inherent uncertainties in the models. In this study, a case study of design and construction of disc cutter change is introduced and analyzed, rather than proposing a prediction model of cutter wear. As the disc cutter is strongly affected by the geological condition, TBM machine characteristic and operation, authors believe it is very hard to suggest a generalized prediction model given the uncertainties and limitations therefore it would be more practical to analyze a real case and provide a detailed discussion of the difference between prediction and result for the cutter change. By doing so, up-to-date idea about planning and execution of cutter change in practice can be promoted.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.533-541
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• 2021

Retaining walls have been used to prevent slope failure through resistance of earth pressure in railway, road, nuclear power plant, dam, and river infrastructure. To calculate dynamic earth pressure and determine the characteristics for seismic behavior, many researchers have analyzed the nonlinear response of ground and structure based on various numerical analyses (FLAC, PLAXIS, ABAQUS etc). In addition, seismic fragility evaluation is performed to ensure safety against earthquakes for structures. In this study, we used the FLAC2D program to understand the seismic response of the inverted T-type wall with a backfill slope, and evaluated seismic fragility based on relative horizontal displacements of the wall. Nonlinear site response analysis was performed for each site (S2 and S4) using the seven ground motions to calculate various seismic loadings reflecting site characteristics. The numerical model was validated based on other numerical models, experiment results, and generalized formula for dynamic active earth pressure. We also determined the damage state and damage index based on the height of retaining wall, and developed the seismic fragility curves. The damage probabilities of the retaining wall for the S4 site were computed to be larger than those for the S2 site.

• Animal Bioscience
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• v.34 no.12
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• pp.1886-1894
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• 2021

Objective: Growth hormone (GH) and insulin-like growth factor I (IGF-I) play a critical role in animal growth rates. We aimed to investigate the effect of GH and IGF-I genotypes on body weight (BW), dominance, and gene expression in slow-growing chickens at different ages. Methods: A total of 613 Korat chickens (KRs) were bred and divided into three groups by genotype - A1A1, A1A3, and A3A3 for GH and AA, AC, and CC for IGF-I. Chickens were weighed every two weeks, and liver and breast muscle tissues were collected at 10 weeks of age. Genetic parameters of KRs were estimated using ASReml software. The GH and IGF-I mRNA levels were measured by quantitative polymerase chain reaction. Significant differences between traits were analyzed using the generalized linear model. Results: A significant effect of GH genotypes on BW was found at most ages, and the A1A1 genotype had the highest value of BW. Compared with the A3A3 genotype, the A1A1 and A1A3 genotypes showed a higher dominance effect at 0 and 2 weeks, and genotype A1A1 had the highest value of dominance at 8 weeks of age. A difference in GH mRNA levels between genotypes was detected in breast muscle at 6 weeks and in the liver tissue at 2 weeks. In the case of IGF-I gene, the AA genotype had the highest BW at the beginning of life. Significant differences in BW dominance were found at 2 weeks. However, IGF-I mRNA levels were not different among genotypes in both breast muscles and liver tissues. Conclusion: Our results revealed that GH and IGF-I influence growth, but may not be involved in heterosis. GH can be used as a marker gene in selection programs for growth because the homozygous genotype (A1A1) had the highest BW at all ages. The IGF-I is not a useful marker gene for selection programs.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.528-542
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• 2021

This study aims to examine the attitudes toward online advertisement targeting YouTube content users and to present implications for the direction and regulation of personal media broadcasting advertisement. The study used the data from 'Awareness of On-line Ads and Blocking Tools' conducted by the Korea Press Foundation in 2020. For the statistical analysis, correspondent analysis was employed. The main results followed as: women tended to perceive more discomfort about the ads before the start of the content compared to men, and women in twenties perceived the highest discomfort with intermediate advertisement. Second, respondents who watch more YouTube contents tended to accept more ads to use contents for free. Third, respondents who are willing to use the advertisement blocking service were most aware of the inconvenience of advertisements before starting of YouTube contents. Although users are aware of the inconvenience, the use of advertisement blocking service has not yet been found to be generalized. However, the use of ad blocking service is expected to increase gradually. It would be expected that efforts to regulate advertisement to reduce discomfort about advertisement among users are also required.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.296-310
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• 2021

El Niño is a typical ocean and atmospheric interaction phenomenon that causes climate variability on a global scale, so it has been used as a very important teaching and learning material in the field of earth science. This study summarized the distribution and dynamics of the equatorial current system. The variability of the equatorial current system during the El Niño period and the associated misconceptions were also investigated. The North Equatorial Current, South Equatorial Current, and Equatorial Under Current significantly weaken during El Niño years. However, the variability of the North Equatorial Counter Current (NECC) during the El Niño period cannot be generalized because the NECC shows southward movement with weakening in the northern area and strengthening in the southern area, along its central axis. In the western Pacific, the NECC is further south during El Niño years, and thus, it has an eastward flow in the equatorial western Pacific. Our analysis of a mass media science article, a secondary school exam, and a survey for incumbent teachers confirmed disparate ideas about the equatorial current system's variability during El Niño periods. This is likely due to inaccurate interpretations of the existing El Niño schematic diagram and insufficient understanding of the equatorial current and wave dynamics.

• Mood & Emotion
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• v.16 no.3
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• pp.158-162
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• 2018

Objectives : The purpose of this study was to examine psychosocial factors related to burnout of social welfare officers working in Jeonnam Province. Methods : A total of 395 social welfare officers (male 99, female 296) working in 22 areas of Jeollanam-do province, were subjects of this study. We examined socio-demographic factors, using a self-reporting questionnaire. Subjects were asked to complete the Maslach Burnout Inventory-General Survey (MBI-GS), Center for Epidemiological Studies Depression Scale (CES-D), Perceived Stress Scale (PSS), and the Generalized Self-Efficacy Scale (GSS), to assess psychosocial factors affecting to burnout of social welfare officers. Results : Among 395 subjects, 221 (55.9%) reported recent experiences of burnout. There was no significant difference in age between two groups, divided by burnout. Sex (p<0.001), rank (p=0.003), working period (p=0.034), depression (p<0.001) revealed differences between the burnout group and control group. Scores of PSS (p<0.001) were higher, while the scores of GSS (p<0.001) were lower in the burnout group, than control group. Multivariate logistic regression analysis revealed that female (OR 2.840, 95%CI 1.466-5.504, p=0.002), depressive high-risk group (OR 6.824, 95%CI 2.893-16.096, p<0.001) PSS (OR 1.247, 95%CI 1.153-1.349, p<0.001) and GSS (OR 0.950, 95%CI 0.930-0.971, p<0.001), were significantly associated with burnout. Conclusion : We found that some factors, were associated with experienced burnout in social welfare officers. Depressive symptoms were the strongest associative factor, for burnout in public servants in charge of social welfare. Sex, stress and self-efficacy also correlated with burnout, and especially self-efficacy was a protecting factor.

• Korea Real Estate Review
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• v.28 no.4
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• pp.7-22
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• 2018

This study aimed to empirically analyze the factors that influence newlyweds' housing tenure. For this, a questionnaire survey was conducted among newlyweds living nationwide who had been married for 5 years or less and were under the age of 40. The results of the survey were empirically analyzed by applying various variables. With regard to parental financial support among the factors influencing newlyweds' housing tenure, the analysis results showed that the probability of owner occupancy was high among the households with parental financial support than among those with none, and the larger the size of the parental financial support was, the higher the probability that the newlyweds owned the house they were occupying. As for the housing loan variable, it was found that the probability of owner occupancy was high among the newlyweds with a housing loan than among those with none, and the larger the amount of the newlyweds' housing loan was, the higher the probability that they owned the house they were occupying. As opposed to what is generally recognized, however, the survey showed that the higher the ratio of dual earners is, the lower the owner occupancy probability due to the probability of job transition, etc. In addition, it was found that the probability of owner occupancy for the newlyweds living in Seoul was lower than that for the newlyweds living in other regions in South Korea. Accordingly, this study showed that appropriate levels of parental economic indicators should also be reflected in the stable housing support and loan policies for newlyweds in the context that the succession to their parents' fortunes is generalized.

• Cross-Cultural Studies
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• v.45
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• pp.195-218
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• 2016

This paper focuses on the terminology of the dictionary as an encyclopedic element in the Buddhist language. The previous study on Buddhist language can be divided into a philosophical approach to the language itself, a review of the linguistic perspective of a specific monk, and a linguistic examination of the Buddhist language. The linguistic examination of the Buddhist language is further divided into analysis of certain Buddhist scriptures, and a study of vocabulary used throughout the Buddhist sphere. The Buddhist vocabulary in the existing Korean dictionary is found in specialized areas such as name, place name, history, and Buddhism. By advancing the generalized words of the terminologies, the meanings of the terminologies and the general words are described as polysemy. It is possible to identify the degree of transition from terminology to general word depending on the distribution of senses. In the case of Buddhist vocabulary, the usage as a general language and as a Buddhist term was given priority, and vocabulary was also derived from a Buddhist term, although it was described as a general language. If a dictionary is changed according to the language unit it contains, the difference in a Buddhist terminology for each dictionary, and a conflict between the existing academic research result and the prior description, will need to be resolved through the collaboration of religious experts, linguists, and lexicographers.

• The Korean Journal of Archival Studies
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• no.5
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• pp.111-148
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• 2002

Digitalization of public administration information shall be accelerated more. When information exists both in the form of electronic and paper record, even the disclosure of paper record make it possible the access to public administration information itself, but there may some needs for the disclosure of electronic record in applicant's situation. Similarly, when only electronic record exists, there may be some problem about whether to disclose the record as print-out or as being electronic format itself. Thus, the method and format of disclose are very sensitive issues, and it is very important to clarify who has the competence to decide the method and format of disclosure, applicant or the public agency. In making any record available to an applicant under the EFOIA in America, the public agency shall provide the record in any form or format requested by the applicant, if the record is readily reproducible by the agency in that form or format. And for the convenience of the applicant with sensory disability, the AIA in Canada also permits the right to access to information in an alternative format. It is desirable also in our country that disclosure of information is done by public agencies in the format that applicant wants, as possible. In the meantime, we should consider the costs and technological restrictions corresponding to the change of format of information to the format that applicant specifies. In the case of electronic record, efforts required for searching cause some hard problems. Information disclosure system requires disclosure of record that exists at the demand point, and creation of new record that does not exist at that them is not required on the public agency. For the search of electronic information, we need some code or program. So, if we evaluate that act of coding or programming as creation of new record, demand on disclosure of electronic record becomes impossible, in fact. Therefore, when we include electronic record as the object of information disclosure system, we need to clarify the degree of reasonable efforts for searching the information included in that record, as long as possible, although it is very difficult problem. Also, we should consider the way to make it permitted to demand the disclosure of electronic record by FAX or E-mail. Disclosure of electronic record itself by E-mail is not generalized yet, even in America or Canada. There are many technological and legal problems to solve, before permitting or enforcing the disclosure of electronic record by E-mail. But, it is desirable to expand the method of disclosure to including disclosure by E-mail in possible spheres. Also, as well as disclosure on demands, we need to expand electronic access to information, so far as possible, in the process of information offer.

• Journal of Korea Technology Innovation Society
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• v.21 no.3
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• pp.1101-1126
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• 2018

As incipient organizations progress from formation to become larger entities, the procedures and rules that provided managerial and structural advantages in having established the organizations and promoting the growth impede the innovation and creativity vital to maintain the competitive advantage. Adopting Corporate Entrepreneurship (CE), large corporations have tried to overcome the dilemma and to sustain the innovation and creativity in order to effectively cope with harsh competitive realities. Recently, some advanced corporations are trying to enhance CE by setting up an internal venture program as a seed organization for CE. By making an in-depth analysis of the internal venture program, 'C-Lab' of Samsung that is promoting CE-related characteristics for enhancing CE, we attempt to shed light on (1) what kinds of environments should be built around the seed organization for CE (2) what are the major characteristics that should be promoted through the seed organization in relation to CE (3) What kinds of achievements can be made from the promoted characteristics (4) How the characteristics are spread over the entire organization. Based on the analysis, we suggest a generalized process in which CE can be enhanced. Since different approaches should be taken for managing the seed organization and spreading the characteristics depending on the strengths and weaknesses of a corporation, there must be the step, 'evaluation of corporate internal capabilities' in the process. We believe that each corporation can enhance CE by taking advantage of the process with reference to the C-Lab case study.