• Molecules and Cells
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• v.38 no.9
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• pp.796-805
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• 2015

Gintonin is a novel ginseng-derived lysophosphatidic acid (LPA) receptor ligand. Oral administration of gintonin ameliorates learning and memory dysfunctions in Alzheimer's disease (AD) animal models. The brain cholinergic system plays a key role in cognitive functions. The brains of AD patients show a reduction in acetylcholine concentration caused by cholinergic system impairments. However, little is known about the role of LPA in the cholinergic system. In this study, we used gintonin to investigate the effect of LPA receptor activation on the cholinergic system in vitro and in vivo using wild-type and AD animal models. Gintonin induced $[Ca^{2+}]_i $ transient in cultured mouse hippocampal neural progenitor cells (NPCs). Gintonin-mediated $[Ca^{2+}]_i $ transients were linked to stimulation of acetylcholine release through LPA receptor activation. Oral administration of gintonin-enriched fraction (25, 50, or 100 mg/kg, 3 weeks) significantly attenuated scopolamine-induced memory impairment. Oral administration of gintonin (25 or 50 mg/kg, 1 2 weeks) also significantly attenuated amyloid-${\beta}$ protein ($A{\beta}$)-induced cholinergic dysfunctions, such as decreased acetylcholine concentration, decreased choline acetyltransferase (ChAT) activity and immunoreactivity, and increased acetylcholine esterase (AChE) activity. In a transgenic AD mouse model, long-term oral administration of gintonin (25 or 50 mg/kg, 3 months) also attenuated AD-related cholinergic impairments. In this study, we showed that activation of G protein-coupled LPA receptors by gintonin is coupled to the regulation of cholinergic functions. Furthermore, this study showed that gintonin could be a novel agent for the restoration of cholinergic system damages due to $A{\beta}$ and could be utilized for AD prevention or therapy.

• Progress in Medical Physics
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• v.26 no.1
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• pp.52-58
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• 2015

The automated dental cavity detection program for a new concept intra-oral dental x-ray imaging device, an auxiliary diagnosis system, which is able to assist a dentist to identify dental caries in an early stage and to make an accurate diagnosis, was to be developed. The primary theory of the automatic dental cavity detection program is divided into two algorithms; one is an image segmentation skill to discriminate between a dental cavity and a normal tooth and the other is a computational method to analyze feature of an tooth image and take an advantage of it for detection of dental cavities. In the present study, it is, first, evaluated how accurately the DRLSE (Direct Regularized Level Set Evolution) method extracts demarcation surrounding the dental cavity. In order to evaluate the ability of the developed algorithm to automatically detect dental cavities, 7 tooth phantoms from incisor to molar were fabricated which contained a various form of cavities. Then, dental cavities in the tooth phantom images were analyzed with the developed algorithm. Except for two cavities whose contours were identified partially, the contours of 12 cavities were correctly discriminated by the automated dental caries detection program, which, consequently, proved the practical feasibility of the automatic dental lesion detection algorithm. However, an efficient and enhanced algorithm is required for its application to the actual dental diagnosis since shapes or conditions of the dental caries are different between individuals and complicated. In the future, the automatic dental cavity detection system will be improved adding pattern recognition or machine learning based algorithm which can deal with information of tooth status.

• Korea and Global Affairs
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• v.1 no.1
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• pp.97-114
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• 2017

This article aims for searching the clue of North Korea nuke-problem by understanding it contextually. We must see this from the beginning as many trials in settling the problem have failed. North Korea nuke-problem is related to the change of international implication as well as the domestic process of its development. At first, it started from the regime survival, which evolved with the effect of learning. During the Cold War, its development had combined the principle of 'self-defense' because of Sino-Russia conflict. Particularly, its meaning varied dramatically due to the collapse of Cold War system plus the advent of post-Cold War system. North Korea nuclear program has became a global problem based on the deterioration of North Korea's security milieu and Bush administration's policy. Therefore, the area of common solution for NK nuke-problem must be found in the context of regime survival and the change of its meaning by continual convergence effort.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.37-53
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• 2012

There is considerable uncertainty in ground properties used in tunnel designs. In this study, a back analysis was performed to find optimal ground properties based on the artificial neural network facility of MATLAB program of using tunnel monitoring data. Total 81 data were constructed by changing elastic modulus and coefficient of lateral pressure which have great influence on tunnel convergence. A sensitivity analysis was conducted to establish an optimal training model by varying the number of hidden layers, the number of nodes, learning rate, and momentum. Meanwhile, the optimal training model was selected by comparing MSE (Mean Squared Error) and coefficient of determination ($R^2$) and was used to find the correct elastic moduli of layers and the coefficient of lateral pressure. In future, it is expected that the suggested method of this study can be applied to determine the optimum tunnel support pattern under given ground conditions.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.415-423
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• 2014

The purpose of this study was to investigate the level of multicultural competencies and influencing factors of multicultural competencies in nursing students. The participants of 181 subjects were recruited from three colleges in K and B. A structured questionnaire was used to collect data, and data were analyzed using descriptive statistics, t-test, one way-ANOVA and multiple regression with SPSS/WIN 17.0. Results showed that cultural competence of nursing students was middle range. There was a significant positive correlation between cultural competence, empathy, and self-efficacy. The significant factors influencing cultural competence of nursing students were empathy, self-efficacy, and education of multiple cultural. These three factors explained 51% of the variance in multicultural competencies of nursing students. The study finding suggest that to develop the learning program with achievement level of multicultural competencies for nursing students.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.1-8
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• 2020

This study analyzed the different needs between the after-school programs of elementary schools in metropolitan and non-metropolitan areas to understand the areas that need addressing to meet with the requisites of the programs. To this end, this study conducted a survey among teachers with experience in after-school management (n=233), and the needs and performance recognized by teachers were analyzed in the IPA model matrix. To sum up the results, 'Online educational infrastructure', 'Efficient administrative operation', and 'Supply of professional after-school instructors' were identified as the prior needs in metropolitan area. On the other hand, non-metropolitan area, 'Supply of professional after-school instructors', 'Quality educational contents', and 'Online educational infrastructure' were identified as the prior requisites to be addressed. Based on research findings, the study suggested implications in developing and implementing related policies. Research findings will be expected to refer as baseline data for activating after-school online program operations and improving its programs to meet with the different needs of regions.

• The Journal of the Convergence on Culture Technology
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• v.1 no.4
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• pp.45-50
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• 2015

Cultures mean communication. With the whole world communicating online simultaneously, international availability has also been required in education. Especially the social media including the YouTube has opened a new age of e-learning, if not intending to do so, and the curriculum of a college or a university has kept up with the needs of our time. This study contains domestic and international professional programs equipped with internalization of a curriculum. It has suggested a role of college of arts as a customized and specialized institution which offers students advanced skills of related international industries through an internationalization of a curriculum of media and arts. It also suggests that full-time faculties need to develop a program to secure an international expertise. It can be concluded that a shift of paradigm towards education industry through social media contributes to needs to secure an international availability of a curriculum.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.147-155
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• 2017

The purpose of this study is to conducted on hotel workers. The results of this study are as follows. First, the relationship between self - efficacy and job performance of employees was analyzed. We distributed 300 questionnaires to domestic L hotel employees. A total of 250 questionnaires were retrieved and 233 copies were used for the final analysis, except for 17 unfair questionnaires. The results showed that hotel workers had a positive influence on self - efficacy. Self - efficacy played a role in the relationship between majors' learning and job performance. Based on the results of the research, we develop an industry-university linkage program. Practical majors will increase the workplace adaptability of employees. And the self - efficacy of the employees will be increased to affect the job performance. In the future, I hope that research on the self-efficacy of hotel employees and post-employment job performance will be carried out in the future.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.425-433
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• 2014

The utilization of robots in programming education students the interest and motivation of learning. But at the same time the robot is required that understanding of the structure and understand the internal program(programming). So what problems are caused by error or if the student has difficulty identifying. The purpose of this study is the use of simulation tool in robot programming education possibilities will want to see. Elementary school students to analyze the possibility of non-simulation tool and simulation tool was applied. And usability evaluation and simulation tool, the survey recognized the potential of the education were analyzed. As a result, the usability of between simulation tool and non-simulation tool and there was no difference. And student can preview the results of programming and simulation tool can easily identify errors for recognizing the positive respectively. Based on this results, simulation tool can be utilized in robot education.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.357-368
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• 2020

This study evaluated soccer-specific fitness early and late season to check the conditioning status of K3 league soccer players. Evaluation factors included body composition, agility, quickness, endurance and isokinetic limb muscle strength. As a result, the factors that showed improvement in the late season were skeletal muscle mass, agility and quickness, and body composition, endurance and isokinetic limb muscle strength were not different from each other. The factors that showed improvement in the second half of the season are thought to be due to the learning effect of repetitive training, competition participation during the season. Lastly, endurance and lower extremity strength did not show improvement in the second half of the season due to the fact that no specific training was performed during the season. Taken together, it is necessary to periodically check the fitness status of athletes to develop and apply a fitness training program suitable for competition, transition and preparation period.