• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.487-497
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• 2018

Water quality improvement processes for stagnant area consist mainly of technologies applying vegetation and artificial water circulation, and these existing technologies have some limits to handle pollution loads effectively. To improve the purification efficiency, eco-friendly technologies should be developed that can reinforce self-purification functions. In this study, a multi-functional floating island combined with physical chemical biological functions ((1) flotation and oxidization using microbubbles, (2) vegetation purification and (3) bio-filtration with improved adsorption capacity) has been developed and basic experiments were performed to determine the optimal combination conditions for each unit process. It has been shown that it is desirable to operate the microbubble unit process under conditions greater than $3.5kgf/cm^2$. In vegetation purification unit process, Yellow Iris (Iris pseudacorus) was suggested to be suitable considering water quality, landscape improvement and maintenance. When granular red-mud was applied to the bio-filtration unit process, it was found that T-P removal efficiency was good and its value was also stable for various linear velocity conditions. The appropriate thickness of filter media was suggested between 30 and 45 cm. In this study, the optimal design and operating parameters of the multi-functional floating island have been presented based on the results of the basic experiments of each unit process.

• Korean Journal of Labor Studies
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• v.24 no.1
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• pp.157-196
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• 2018

This study analyzes non-standard workers' attitudes and behaviors towards standard workers' strikes using the case of a joint strike held by journalists at KBS and MBC in 2012. Tracing the process since 2008 by which a conservative government has tried to control the press and regular journalists have collectively resisted against it, we put our analytical focus on two major groups of freelance broadcast professionals: independent producers and writers in current affairs. Specifically, we examine 1) how they perceived and responded to a series of regular journalists' struggle to protect journalistic value, 2) how such perception of and response to regular journalists could be developed, and 3) how (de)solidarity could form and then deepened between freelance and regular journalists in the 2012 Media Strike. Our findings show that the ways in which regular journalists had controlled freelance journalists at work affected the relationship between class-based and occupation-based rationality freelance journalists held in their minds. Independent producers, who had developed a strong class-based rationality in response to the coercive input-output control, showed cynicism about regular journalists' strike pointing out their hypocrisy and contradiction. In contrast, freelance writers accommodated and joined the strike by regular workers in the spirit of solidarity based on occupational rationality which had developed from normative, process control. Our paper ends with theoretical and practical implications.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.309-316
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• 2019

In this paper, a low-jitter delay-locked loop that compensates for local clock skew is presented. The proposed DLL consists of a phase splitter, a phase detector(PD), a charge pump, a bias generator, a voltage-controlled delay line(VCDL), and a level converter. The VCDL uses self-biased delay cells using current mode logic(CML) to have insensitive characteristics to temperature and supply noises. The phase splitter generates two reference clocks which are used as the differential inputs of the VCDL. The PD uses the only single clock from the phase splitter because the PD in the proposed circuit uses CMOS logic that consumes less power compared to CML. Therefore, the output of the VCDL is also converted to the rail-to-rail signal by the level converter for the PD as well as the local clock distribution circuit. The proposed circuit has been designed with a $0.13-{\mu}m$ CMOS process. A global CLK with a frequency of 1-GHz is externally applied to the circuit. As a result, after about 19 cycles, the proposed DLL is locked at a point that the control voltage is 597.83mV with the jitter of 1.05ps.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.251-259
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• 2021

Due to the characteristic that early childhood education is a process of nurturing children's senses by a leader rather than the transfer of knowledge, even in the era of with Corona, early childhood distance education is not one-to-one non-face-to-face education, but rather through distributed materials such as early childhood education packages or media such as TV. Distance education was conducted in a self-care method. Through a review of prior research and intensive parent interviews, the researcher identified the requirements for distance education, such as the expansion and accessibility of educational contents, understanding of basic knowledge of early childhood distance education, and the need to increase children's social skills through real-time distance education. It was identified that the current distance education-related solutions are not suitable for early childhood education. Accordingly, the researcher presents the basic direction (VERI) of the early childhood distance education solution of diversity, ease, real-time communication, and integration, and provides a Web/App platform that allows children, parents, and teachers to share content and communicate in real time and in non-real time. The development of a solution was proposed. This distance education solution is expected to effectively support early childhood distance education in the era of With Corona as infants, parents, and teachers communicate and share the current situation, which is only presenting guidelines and materials.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.266-279
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• 2021

This study applied the e-PBL (e-Project-based learning) method for "Urban Forest Management" courses in the Department of Forest Science at S University to progress in university forest education. e-PBL effectively motivates self-directed learning, problem-solving, communication skills, and learners' responsibility by enabling them to choose, design, and perform their projects. Due to the COVID-19 pandemic in 2020, learners were encouraged to use online media to carry out projects and submit presentations for the campus forest. Learners' educational effects were subsequently investigated through a five-point Likert scale. This study discovered a positive effect on learners' motivation and interest (4.17) through e-PBL. Learners responded that e-PBL also helped their understanding regarding the subject (4.17). In addition, this study provided evidence that the e-PBL method was helpful in problem-solving (4.25), communication (4.33), and decision-making skills (4.21). According to learners' responses, there are positive indications that learners were satisfied with e-PBL. Learners responded that interactions and communications with team members could improve their understanding of the subject. Hence, there is scope for improving an efficient and successful e-PBL model suitable for university forest education by providing more efficient instructional time management, e-PBL method guidelines, and institutional support.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.944-953
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• 2020

Object detection plays a crucial role in a self-driving system. With the advances of image recognition based on deep convolutional neural networks, researches on object detection have been actively explored. In this paper, we proposed a lightweight model of the mask R-CNN, which has been most widely used for object detection, to efficiently predict location and shape of various objects on the road environment. Furthermore, feature maps are adaptively re-calibrated to improve the detection performance by applying an attention module to the neural network layer that plays different roles within the mask R-CNN. Various experimental results for real driving scenes demonstrate that the proposed method is able to maintain the high detection performance with significantly reduced network parameters.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.973-979
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• 2020

This study aims to objectively and quantitatively determine the social emotion of empathy by collecting pupillary response. 52 subjects (26 men and 26 women) voluntarily participated in the experiment. After the measurement of the reference of 30 seconds, the experiment was divided into the task of imitation and spontaneously self-expression. The two subjects were interacted through facial expressions, and the pupil images were recorded. The pupil data was processed through binarization and circular edge detection algorithm, and outlier detection and removal technique was used to reject eye-blinking. The pupil size according to the empathy was confirmed for statistical significance with test of normality and independent sample t-test. Statistical analysis results, the pupil size was significantly different between empathy (M ± SD = 0.050 ± 1.817)) and non-empathy (M ± SD = 1.659 ± 1.514) condition (t(92) = -4.629, p = 0.000). The rule of empathy according to the pupil size was defined through discriminant analysis, and the rule was verified (Estimation accuracy: 75%) new 12 subjects (6 men and 6 women, mean age ± SD = 22.84 ± 1.57 years). The method proposed in this study is non-contact camera technology and is expected to be utilized in various virtual reality with smart glasses.

• Animal Bioscience
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• v.34 no.8
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• pp.1392-1402
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• 2021

Objective: The growth rate of pigs is related to differentiation and proliferation of muscle cells, which are regulated by growth factors and expression of growth-related genes. Thus, the objective of this study was to establish optimal culture conditions for Jeju black pig (JBP) muscle cells and determine the relationship of various factors involved in muscle growth with the proliferation of JBP muscle cells. Methods: Muscles were taken from the femur skeletal muscle of JBP embryos. After isolation of the muscle cells, cells were cultured in a 6-well plate under four different culture conditions to optimize culture conditions for JBP muscle cells. To analyze proliferation rate of JBP muscle cells, these muscle cells were seeded into 6-well plates at a density of 1.5×10⁵ cells per well and cultured for 3 days. Western blot and quantitative real-time polymerase chain reaction were applied to verify the myogenic differentiation 1 (MyoD) expression and growth-related gene expression in JBP muscle cells, respectively. Results: We established a muscle cell line from JBP embryos and optimized its culture conditions. These muscle cells were positive for MyoD, but not for paired box 7. The proliferation rate of these muscle cells was significantly higher in a culture medium containing bFGF and epidermal growth factor + basic fibroblast growth factor (EGF+bFGF) than that without a growth factor or containing EGF alone. Treatment with EGF and bFGF significantly induced the expression of MyoD protein, an important transcription factor in muscle cells. Moreover, we checked the changes of expression of growth-related genes in JBP muscle cells by presence or absence of growth factors. Expression level of collagen type XXI alpha 1 gene was changed only when EGF and bFGF were added together to culture media for JBP muscle cells. Conclusion: Concurrent use of EGF and bFGF increased the expression of MyoD protein, thus regulating the proliferation of JBP muscle cells and the expression of growth-related genes.

• Journal of Korean Academy of Dental Administration
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• v.7 no.1
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• pp.21-28
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• 2019

The purpose of this study was to investigate the association between wrong postures and pain during scaling and encourage dental hygienists and students to exercise scaling in a good position. After obtaining informed consent, 107 students (3rd and 4th grade students) who had an experience with scaling practice were enrolled. The questionnaire included three general items, four items related to the posture during scaling, and nine items related to pain management (total 16 items), for which the five-point Likert scale was used. Through the questionnaire, we examined the preference of posture during scaling, posture education during scaling, pain in each part during scaling, pain management, and pain management method. In the scaling exercise, 86.3% of the subjects were instructed on the correct posture, and 87.9% of the subjects perceived the possibility of inducing musculoskeletal disorders based on the scaling posture. The percentage of subjects who responded that they performed scaling in the correct posture was 33.6% and that of subjects who answered that they bowed or turned their head by more than 15° was 64.4%. Further, 45.7% of the subjects answered that they bent their shoulders, and 29.9% of the subjects answered that their postures were not parallel to the floor. Pain during scaling was still higher when they bent their head, they bent their waist, and they bent their wrist (p<0.05). During scaling, pain was most frequent in the fingers and hands (15%), followed by the neck (14%), shoulders (11.2%), waist (9.3%), and feet and legs (2.8%). The percentage of subjects who performed regular exercise (or stretching) to prevent pain was 29.9% and that of subjects who managed pain after scaling was 12.1%. Further, exercise (24.6%) and self-massage (20.3%) were highly used as the pain management methods, and the school practice was preferred to education media for pain management (79.4%). In the scaling practice, there was a training on pain management, but the frequency of practicing in the wrong posture was high. Moreover, pain increased upon practicing in an incorrect posture. Therefore, more in-depth and systematic education on the necessity and method of musculoskeletal disease management during scaling is required.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.599-606
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• 2022

This study investigates trends and changes in gender expression in film and animation. It compares how gender, race, and class discrimination that was socially and culturally expressed differently in past and modern media contents. Indiscriminate content appreciation by the "digital native" generation is likely to unconsciously create false stereotypes. In this study, 「Aladdin」(1992) and 「Aladdin」(2019) were analyzed. This study looks at in the characters have changed since the original, which was a 2D animation in 1992, was re-released as a live-action film in 2019. For character analysis, we compare and analyze major characters and find out the differences based on the nine personality types of Enneagram, which define human personality types. As a result, Princess Jasmine's character change was remarkable. In the past, Disney animations had the majority of patriarchal and male-dependent princess characters, but now Disney is aiming for self-directed and independent female characters. Also, scenes that could instill stereotypes of gender, race, and class were changed. Disney's change can be seen as expressing the gender image that the public wants. Analysis of the change in character's personality in these works can be a useful methodology for creating attractive characters for the public.