• Journal of the korean society of oceanography
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• v.32 no.4
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• pp.181-190
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• 1997

A large subtidal sand ridge (Jungang Satoe) in Asan Bay, on the west coast of Korea, was studied in order to understand the morphology and sediment transport trend in a macrotidal setting, by means of analyzing sediment samples, current data, side-scan sonographs and seismic profiles. The ridge is about 15 km long and 2-5 km wide, with a relief of about 15 m. It is elongated in the flow direction of flood (SE) and ebb (NW) tidal currents, but asymmetrical in cross section. The western and southwestern side of the ridge is characterized by relatively gentle slopes averaging 0.4$^{\circ}$, whereas on the northeastern side, relatively steep slopes were mapped with 1.6$^{\circ}$ slope angles. Tidal currents associated with the ridge are very strong; maximum surface velo-cities range from neap values of 50 cm/s to spring values of 130 cm/s. The shear velocities during flood and ebb are strong enough to erode and transport sands on the ridge. Sand waves and megaripples (dunes) are the most common bedforms produced by the tidal currents, which show regional differences in shape and size on the ridge. The distribution pattern of these bedforms in-dicates that the flood tidal currents are dominant on the offshore (northwest) side of the ridge, whereas the onsho.e (southeast) side of the ridge is ebb-dominated. The sand transport path as inferred from bedform orientations is directed toward the ridge crest on the flanks, whereas on the crest, it is near-longitudinal to the ridge axis. The convergent, upslope movement of sands on the ridge flanks appears to be important in sand ridge building and maintenance. A significant ridge migration toward the northeast can be suspected on the basis of the ridge morphology, which may cause offshore hazards for navigation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.177-183
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• 2015

Incremental sheet metal forming is a manufacturing process to produce thin parts using sheet metals by a series of small incremental deformation. The process rarely needs dedicated dies and molds, thus, preparation time for the process is relatively short as to be compared to conventional metal forming. Spring back in sheet metal working is very common, which causes critical errors in dimensions. Incremental sheet metal forming is not fully investigated yet. Hence, incremental sheet metal forming frequently produces inaccurate parts. This paper proposes a method to minimize dimensional errors to improve shape accuracy of products manufactured by incremental forming. This study conducts experiments using an exclusive incremental forming machine and the material for these experiments are sheets of aluminum AL1015. This research defines a process parameter and selects a few factors for the experiments. The parameters employed in this paper are tool feed rate, tool diameter, step depth, material thickness, forming method, dies applied, and tool path method. In addition, their levels for each factor are determined. The plan of the experiments is designed using orthogonal array $L_8$ ($2^7$) which requires minimum number of experiments. Based on the measurements, dimensional errors are collected both on the tool contacted surfaces and on the non-contacted surfaces. The distances between the formed surfaces and the CAD models are scanned and recorded using a commercial software product. These collected data are statistically analyzed and ANOVAs (analysis of variances) are drawn up. From the ANOVAs, this paper concludes that the process parameters of tool diameter, forming depth, and forming method are the significant factors to reduce the errors on the tool contacted surface. On the other hand, the experimental factors of forming method and dies applied are the significant factors on the non-contacted surface. However, the negative forming method always produces better accuracy than the positive forming method.

• Safety and Health at Work
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• v.7 no.2
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• pp.124-129
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• 2016

Background: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. Methods: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (${\Delta}$ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The ${\Delta}$ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. Results: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single ${\Delta}$ score of subjective fatigue. Conclusion: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

• Safety and Health at Work
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• v.10 no.3
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• pp.260-264
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• 2019

Background: Professional dance is a physically demanding career path with a high injury prevalence, yet an ingrained culture of hiding or pushing through injuries. Developing better knowledge surrounding the cultural beliefs and behaviors related to injury reporting is critical to understand their incidence and burden. Therefore, the aim of this study was to investigate injury fear and injury reporting behaviors in professional dancers in Australia. Methods: This study utilized data collected in a cross-sectional survey of professional dancers in Australia. Descriptive analysis of injury fear and reporting stigma are presented with comparisons between subgroups (full-time versus part-time dancers; men versus women) conducted using two-sided Fisher's exact tests. Results: A total of 146 professional dancers were included. Over half (63%) of the respondents reported that they fear sustaining a dance-related injury, that they believe there is still a stigma surrounding injuries in dance (62%), and that this stigma has led to a delay in reporting or seeking care for an injury (51%). A lower proportion of part-time than full-time dancers reported that they would usually tell someone within their dance employment about an injury (35.1% vs. 59.6%, p = 0.006). Conclusion: Professional dancers are at risk of losing contracts or roles if they are injured, and therefore, it is common to dance through their occurrence. Many dancers, particularly those dancing part-time, are unwilling to tell their employers about their injuries. Action is required to improve this culture regarding injury reporting and help seeking for more effective injury understanding, prevention, and management in dance.

• Journal of Technologic Dentistry
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• v.41 no.3
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• pp.233-244
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• 2019

Purpose: The purpose of the study is to learn the importance of self-directed learning about career-preparation behavior of department of dental technology students. Methods: Using the questionnaire, the department of dental technology in Gyeongnam Province conducted a survey of students of department of dental technology at A and B college for one month from May 15, 2019 through June 15, 2019, and finally 204 students were surveyed for Self-esteem, Self-determination, Self-efficacy, Internal control, College life adaptation, Self-directed learning, and Career-preparation behavior. Results: Self-esteem among students has been shown to improve self-directed learning by increasing the stress of college life, and self-efficacy has only a direct effect on self-directed learning. In addition, self-determination and internal control of department of dental technology students were found to be variables that have a common positive effect on college life adaptation and self-directed learning. In addition, college life adaptation gives direct positive effect to self-directed learning, but indirect effect through self-directed learning was found to be stronger than direct effect on career-preparation behavior, and the career-preparation behavior of students was further strengthened through self-directed learning. Conclusion: The changes in college restructuring and various policies also suggest that students should actively seek ways to instill certainty about their major's vision and career path within the college rather than deciding their future through extreme measures such as academic secession at a time when anxiety and uncertainty about their career is strong.

• Physical Therapy Korea
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• v.29 no.1
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• pp.19-27
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• 2022

Background: Foot drop is a common symptom in stroke patients. Tape applications are widely used to manage foot drop symptoms. Previous studies have evaluated the effects of static and dynamic balance and gait on foot drop using kinesiology tape; however, only few studies have used dynamic tape application in stroke patients with foot drop. Objects: The purpose of this study was to investigate the immediate effects of dynamic taping, which facilitates the dorsiflexor muscle, on static and dynamic balance and gait speed in stroke patients with foot drop. Methods: The study included 34 voluntary patients (17 men, 17 women) with stroke. The patients were randomly assigned to the experimental group (n = 17), wherein dynamic taping was used to facilitate the dorsiflexor muscle, or the control group (n = 17), wherein kinesiology taping was used. Before the taping application, velocity average, path-length average, Berg balance scale, and timed up and go test (TUG) were recorded to measure static and dynamic balance, whereas the 10-meter walk test (10MWT) was used to measure gait speed. After the taping application, these parameters were re-evaluated in both groups. Repeated measure analysis of variance was used. Statistical significance levels were set to α = 0.05. Results: Except for the 10MWT scores in the control group, significant differences were noted in all the parameters measured for static and dynamic balance and gait speed between the pre and post-test (p < 0.05). However, the parameters showed significant interaction effects between group and time in the TUG and 10MWT (p < 0.01). Conclusion: These results indicate that compared with kinesiology taping, dynamic taping used in chronic stroke patients with foot drop had a more significant effect on dynamic balance and gait speed.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.142-154
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• 2023

The canine tooth is important both functionally and aesthetically, being positioned between the anterior and posterior teeth. The upper canine has the longest eruption path, forming in the deepest part of the maxillary bone and often experiencing eruption disorders, leading to significant aesthetic and functional issues. Early detection and management of canine impaction are crucial in pediatric dentistry, which focuses on tooth growth and eruption. The prevalence of maxillary canine impaction ranges from 1.1% to 3.0%. In Western populations, palatal impaction is twice as common as labial impaction, while some Korean studies report more labial impaction. Maxillary canine impaction occurs more frequently in women and is associated with various factors such as structural obstacles, pathological conditions in surrounding tissues, developmental abnormalities, and genetic factors. Labial displaced canines are linked to narrow maxillary intercanine width, total dental crowding, and skeletal Class III malocclusion. Maxillary palatal displaced canine impaction is more prevalent in patients with familial agenesis of lateral incisors or conical supernumerary lateral incisors. Understanding these factors aids in early diagnosis and appropriate intervention for canine tooth impaction, ensuring optimal oral health and aesthetics.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.457-462
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• 2023

Director Yoon Jong-bin's new series <The Accidental Narco, Narco-Saints> was streamed through Netflix in 2022 and ranked first in the series rankings. <The Accidental Narco, Narco-Saints> continues the genealogy of male narratives in Korean society that director Yoon Jong-bin has pursued for a long time. In <The Accidental Narco, Narco-Saints>, the main characters choose the path of the diaspora to escape Korean society and seek survival in a foreign country. The two male protagonists of <The Accidental Narco, Narco-Saints> are set up in a hostile relationship, but they have one thing in common: they basically pursue money to "survive". They chose the diaspora to avoid the tyranny of public power in Korean society in the 1980s and 1990s, but Republic of Suriname was the worst place where private violence and public power were completely callused. In there, one becomes a drug lord and the other chooses to act for his duty to Korea. These two different choices can be said to be examples of the light and shade of the diaspora. In <The Accidental Narco, Narco-Saints>, director Yoon Jong-bin inherited the themes of 'family' and 'violence' from previous works, while expanding the geographical area of Korean male narratives he had been exploring.

• Journal of Korea Trade
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• v.26 no.6
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• pp.41-60
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• 2022

Purpose - The policy implications of free trade agreements have traditionally been a matter of debate among economists. The official signing of the Korea-China Free Trade Agreement provides economists with a quasi-natural experiment to analyze the FTA's policy effects. This article aims to more accurately understand the impact of Korea's FTA accession on the macro economy. Design/methodology - This study adopts the counterfactual method based on panel data to find common factors in the generation process of macro data to fit the counterfactual path, to accurately evaluate the effect of the macro policy. Findings - Our research results show that the signing of the Korea-China FTA has a relatively significant short-term positive effect on Korea's economic growth. On average, Korea's real GDP growth rate has increased by 2.1%. This study finds evidence in support of FTA signing not having a significant impact on Korea's GDP growth in the long run. Additionally, we evaluated the impact of the FTA on Korea's imports and exports and found that it had a significant positive impact in the short term, but the trade effect of the FTA is significantly affected by the external macro-environment. Originality/value - First, this study uses macro panel data at the national level to examine the impact of the Korea-China FTA on Korea, and more accurately describes the policy effect of the FTA. Second, our empirical results show that the Korea-China FTA policy impact is subject to occasional changes in the external environment, such as the geopolitical conflict (crisis) between Korea and China, and the US-China trade war. Finally, the analysis shows that the short-term effect of FTA is significant but the long-term is uncertain, which provides empirical evidence for the debate on whether joining FTA can promote national economic growth.

• International Area Studies Review
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• v.15 no.1
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• pp.135-169
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• 2011

This study is for analyzing the management performances of Korean tourism firms, operating as preparing strategically against FTA which is one of the most importantly external environment in international management since in the middle of 1990s. The main purpose is to test empirically some relations between the management performances and the levels of ownership-specifics advantages of Korean tourism ones. To be exact, the dependent variables of management performances are classified with sales, profits and management satisfaction, while the independent ones of the competitive advantages are sorted with the 5 following factors like marketing, product development, service supply, finance and organization culture. The survey of Korean tourism enterprises engaging in management activities in Korea is implemented by collecting questionnaires. And for testing the hypothesis, the analyzing tools are being used for correlation, reliability, validity, multi regression and the path analysis of structural equation modeling. As a result, Marketing is certified as only common factor to influence three dependent variables of sales, profit and management satisfaction positively.