• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.264-274
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• 2020

The Ro-Ro ferry ship capsized and sank to the bottom of the sea because of the rapid turning for several reasons, such as lack of stability due to the center of gravity rise from the extension and rebuilding of the stern cabin, excessive cargo loading, and shortage ballast, poor lashing, etc. The purpose of this study was to investigate and analyze the cause of the ship's rapid flooding, capsizing, and sinking accident according to rapid turning scientifically and accurately using the Fluid-Structure Interaction( FSI) analysis technique. Several tests were conducted for this cause investigation of the flooding and sinking accident correctly and objectively, such as the realization of the accurate ship posture tracks according to the accident time using several accident movies and photos, the validation of cargo moving track, and sea water inflow amount through the exterior openings and interior paths compared with the ship's posture according to the accident time using the floating simulation and hydrostatic characteristics program calculation, and the performance of a full-scale ship flooding·sinking simulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.4_1
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• pp.363-371
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• 2014

Most space-borne optical scanning systems adopt linear arrayconfigurations. The well-knownthree different types of space-borne sensors arealong-track line scanner, across-track linescanner, and three line scanner. To acquire accurate location information of an object on the ground withthose sensors, the exterior and interior orientation parameters are critical factors for both of space-borne and airborne missions. Since the imaging geometry of sensors mightchange time to time due to thermal influence, vibration, and wind, it is very important to analyze the Interior Orientation Parameters (IOP) effects on the ground. The experiments based on synthetic datasets arecarried out while the focal length biases are changing. Also, both high and low altitudes of the imagingsensor were applied. In case with the along-track line scanner, the focal length bias caused errors along the scanline direction. In the other case with the across-track one, the focal length bias caused errors alongthe scan line and vertical directions. Lastly, vertical errors were observed in the case ofthree-line scanner. Those results from this study will be able to provide the guideline for developing new linearsensors, so as for improving the accuracy of laboratory or in-flight sensor calibrations.

• Journal of Mushroom
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• v.19 no.3
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• pp.176-183
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• 2021

In this study, the anti-inflammatory activity of an extract of the fruiting body of the Tuber himalayense (TH) truffle collected from oak growing areas in Korea was investigated. The extract was not cytotoxic at concentrations below 100 ㎍/mL in an experiment evaluating inflammation inhibitory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE₂) production was inhibited by the extract in a concentration-dependent manner. Western blot assay results indicated that the anti-inflammatory activity of TH extract was likely caused by the reduced production of NO and PGE₂ via suppression of induced NO synthase and cyclooxygenase-2 gene expression. In addition, TH extract effectively inhibited the production of interleukin (IL)-1β and IL-6 by macrophages. Thus, TH extract effectively inhibits the overexpression of various inflammatory mediators and could be valuable in formulating anti-inflammatory foods and medicines that target these components.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.513-523
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• 2019

The purpose of this study is to investigate the perception of pre-service secondary English teachers on peer feedback in English composition. For this purpose, a total of 37 students who took the English composition class for 15 weeks participated in the survey. After completing the survey, data were analyzed to find out the students' perception on peer feedback performed in their English composition class through frequency analysis and descriptive statistics. The findings of this study are as follows: First, the students showed positive attitudes towards on peer feedback activities. Second, the participants had received considerable help in the content, ideas and organization of their composition. Third, noticing that they all have made similar mistakes in their writing, the subjects were relieved to know that they are not falling behind their other colleagues. Fourth, the subjects did not trust the feedback contents among the peers, which were found in both the feedback giver and receiver. In particular, feedback from peers who had low English proficiency was rarely helpful. Fifth, the students were afraid that their relationship might become uncomfortable with peers when they pointed out peer's writing errors or made specific suggestions about their peer's writing. Finally, pedagogical implications were discussed based on the research findings.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.439-448
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• 2018

With the aim of examining changes in plantar pressure while walking depending on the position of carrying a bag, this study measured the plantar pressure of 33 normal male and female adults using the F-scan System in four different positions to carry a bag: walking without carrying a bag; walking with carrying a bag on both shoulders; walking with carrying a bag on one shoulder; and walking with carrying a bag in one hand. Changes in the plantar pressure of the subjects obtained in this study and the asymmetry of the left and right feet were analyzed. The plantar pressure of the different areas of the feet in the four different positions to carry a bag was compared. The left foot, except its toes and metatarsus, showed a statistically significant difference among the five conditions, and the right foot, except its 4th and 5th caput metatarsalis, also showed a statistically significant difference (P>.05). Given the results of this study, this experiment to examine changes in plantar pressure does not seem to be enough to identify which position to carry a bag, except carrying a bag on both shoulders, would have the lowest negative impact on the feet. It will be necessary to conduct a follow-up study on changes in plantar pressure depending on the position of carrying a bag and methods that can effectively treat abnormal positions such as scoliosis and kyphosis using asymmetric loads.

• Geophysics and Geophysical Exploration
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• v.22 no.3
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• pp.149-159
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• 2019

Borehole elemental concentration logging, measuring neutron-induced gamma rays by inelastic scattering and neutron capture interactions between neutron and formation, delivers concentrations of the most common elements found in the minerals and fluids of subsurface formation. X-ray diffraction and X-ray fluorescence analysis from core samples are traditionally used to understand formation composition and mineralogy, but it represents only part of formations. Additionally, it is difficult to obtain elemental analysis over the whole intervals because of poor core recovery zones such as fractures or sand layers mainly responsible for groundwater flow. The development of borehole technique for in situ elemental analysis plays a key role in assessing subsurface environment. Although this technology has advanced consistently starting from conventional and unconventional resources evaluation, it has been considered as exclusive techniques of some major service company. As regards domestic research and development, it has still remained an unexplored field because of some barriers such as the deficiency of detailed information on tools and calibration facility for chemistry and mineralogy database. This article reviews the basic theory of spectroscopy measurements, system configuration, calibration facility, and current status. In addition, this article introduces the domestic researches and self-development status on borehole elemental concentration tools.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.137-144
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• 2019

The purpose of this study is to investigate the relationship between the perception of dying with dignity and the quality of life based on the opinions of the Korean populations. The participants were selected using a stratified proportional allocation method and 1,000 adults aged between 19 and 74 years from 17 municipalities and provinces in Korea. The questionnaire consisted of 2 demographic items; 26 items on the quality of life scale; and 57 items on the perception of dying with dignity. The statistical methods used included frequency analyses, independent sample t-tests, and correlation analyses. The results showed that the quality of life was highest for the social life quality item, and that the participants who had experienced a death in the family were more likely to have statistically lower quality of life in physical, psychological, environmental, and social areas. In terms of the participants' perception on dying with dignity, the score for death preparation was the highest; specifically, the score for psychological/economic burden reduction was the highest. The quality of life of the participants showed a positive correlation in all aspects of the perception of dying with dignity: physical symptoms and control, death preparation, death environment, family and social relations, hospital treatment, psychological dignity, and spirituality. Other studies conducted with middle-aged populations showed that their quality of life was higher when they perceived the acceptance of death is important and were willing to participate in death preparation education. Therefore, in order to improve the quality of life and have a positive influence on the participants, educational programs on death preparation and dying with dignity considering all the areas of the perception of dying with dignity should be provided.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.243-249
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• 2021

The star tracker detects microscopic star light in space and compares it with a stored list of stars to calculate the satellite's position in the inertial coordinate system. If other light, such as the sun or the earth, enters the optical head, the star cannot be recognized and the star tracker cannot be operated. In particular, strong light such as the sun affects not only operation but also the performance of the star tracker. The sun exclusion angle of the star tracker is one of the important factors determining the performance of the star tracker. This paper performs the verification of the star tracker's sun exclusion angle. In order to verify the sun exclusion angle, we predict the sun exclusion time of the star tracker and compare it to the actual sun exclusion time of the GEO-KOMPSAT-2A star tracker. In addition, the performance of the star tracker is analyzed for normal operations against the sun exclusion in the optical head. It shows that the actual sun exclusion is maintained under the range of 26 degrees, the performance requirement of the star tracker, and the star tracker operates normally in spite of the sun exclusion.

• Journal of agriculture & life science
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• v.53 no.4
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• pp.113-124
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• 2019

In this study, the operational characteristics of a cam-type vegetable transplanter which usually used in domestic was analyzed and operating mechanism of a transplanting device was analyzed. The main components and power path of the transplanter were analyzed. The maximum and minimum control cycles according to the moving speed and the plant spacing were analyzed. 3D modeling and simulation were performed to derive the trajectory of the bottom end of the transplanting hopper and the plant spacing at the each operating condition. The simulation results were verified by the field tests. As main findings of this study, the transplanting device has one degree of freedom (DOF) which consist of 13 links, 17 rotating joints and 1 half joint, and each part has composite structure with cam and links. By continuous and repetitive motion of the structures of transplanting device, the transplanting hopper plants the seedling in the ground with a vertical direction, and the seedling was planted stably. The power is transmitted to the driving part and transplanting device from the engine, and the maximum and minimum plant spacing of the transplanting device were about 900 mm and 350 mm, respectively.

• Journal of the Korea Convergence Society
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• v.12 no.1
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• pp.369-377
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• 2021

Augmented reality smart-glass enables healthcare providers to use patient and their care related information without interference of workflow. In addition, augmented reality smart-glass simulation had advantages in improving competency via remote collaboration and real-time information sharing. This study investigated perception and attitude regarding augmented reality smart glass based healthcare simulation on three different groups of healthcare major students, computer major students, developers and faculties. Using convenience sampling method, data were obtained from 95 participants and statistical analysis were performed using SPSS 25.0. Developer and faculty group showed the highest scores, followed by healthcare major students. There was the high expectation on augmented reality smart-glass for skill acquisition and the high performance and big screen were essential features of device. The findings of this study revealed that differences between healthcare and computer major students exist and strategies to reduce those gaps are required to adopt augmented reality smart glass in healthcare settings.