• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.309-316
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• 2024

The U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide (RG) 1.20 provides guidance on the comprehensive vibration assessment program (CVAP) to be performed on reactor internals during preoperational and startup tests. The purpose of the program is to identify loads that could cause vibration in the reactor internals and to ensure that these vibrations do not affect their structural integrity. The structural vibrational analysis program involves creating finite element analysis models of the reactor internals and calculating their structural responses when subjected to vibration loads. The appropriateness of the structural analysis methodology must be demonstrated through benchmarks or any other reasonable means. Although existing structural analysis methodologies have been proven to be appropriate and are widely used, this paper presents the development of an improved new structural analysis methodology for APR1400 reactor internals using scaled model tests.

• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.65-71
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• 2013

Objective : In order to develop a novel nerve guidance channel using porcine small intestinal submucosa (SIS) for nerve regeneration, we investigated the possibility of SIS, a tissue consisting of acellular collagen material without cellular immunogenicity, and containing many kinds of growth factors, as a natural material with a new bioactive functionality. Methods : Left sciatic nerves were cut 5 mm in length, in 14 Sprague-Dawley rats. Grafts between the cut nerve ends were performed with a silicone tube (Silicon group, n=7) and rolled porcine SIS (SIS group, n=7). All rats underwent a motor function test and an electromyography (EMG) study on 4 and 10 weeks after grafting. After last EMG studies, the grafts, including proximal and distal nerve segments, were retrieved for histological analysis. Results : Foot ulcers, due to hypesthesia, were fewer in SIS group than in Silicon group. The run time tests for motor function study were 2.67 seconds in Silicon group and 5.92 seconds in SIS group. Rats in SIS group showed a better EMG response for distal motor latency and amplitude than in Silicon group. Histologically, all grafts contained some axons and myelination. However, the number of axons and the degree of myelination were significantly higher in SIS group than Silicon group. Conclusion : These results show that the porcine SIS was an excellent option as a natural biomaterial for peripheral nerve regeneration since this material contains many kinds of nerve growth factors. Furthermore, it could be used as a biocompatible barrier covering neural tissue.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.3
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• pp.228-235
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• 2010

This paper deals with an autonomous flight controller design problem for a tilt-rotor aircraft in rotary-wing mode. The inner-loop algorithm is designed using the output-based approximate feedback linearization. The model error originated from the feedback linearization is cancelled within allowable tolerance by using single-hidden-layer neural network. According to Lyapunov direct stability theory, the adaptive update law is derived to run the neural network on-line, which is based on the linear observer dynamics. Moreover, the outer-loop algorithm is designed to track the trajectory generated from way-point guidance. Especially, heading and flight-path angle line-of-sight guidance are applied to the outer-loop to improve accuracy of the landing tracking performance. The 6-DOF nonlinear simulation shows that the overall performance of the flight control algorithm is satisfactory even though the collective input response shows instantaneous actuator saturation for a short time due to the lack of the neural network and the saturation protection logic in that loop.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.87-94
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• 1999

Backgroud: We have performed the CT-guided celiac plexus block (CPB) using anterior approach to evaluate the safety and efficacy of the procedure and to determine the role of CT. Methods: CPB were done in 10 patients (5 men and 5 women: mean age, 58.1 years) with intractable upper abdominal pain due to terminal malignancy of the stomach (n=3), pancreas (n=4), gallbladder (n=2), and liver (n=1). To permit an anterior approach, patients lay supine on the CT scan table during the procedure. One 21-guage Chiba needle was placed just anterior to the diaphragmatic crus between the celiac and superior mesenteric arteries and 10~12 ml of dehydrated alcohol was injected. Degree of pain relief following the procedure was assessed and pain was graded on a numeric rating scale (NRS) from 0 to 10. Results: The results suggest a direct relation between the degree of celiac invasion and the response to the CPB. With CT guidance, it is possible for us to direct the needle into more accurate region, allowing alcohol to be deposited in specific ganglion area. Conclusions: CT-guided CPB using an anterior approach was an easy and effective way of reducing intractable upper abdominal pain due to terminal malignancies. CT-guidance allowed precise needle placement and safe procedure. Careful classification of cases is important to predict the degree of pain relief using the grading system based on the degree of involvement of the celiac plexus.

• Journal of Korean society of Dental Hygiene
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• v.14 no.2
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• pp.231-240
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• 2014

Objectives : The purpose of this study was to examine the oral health programs for children of the low income classes in order to prevent oral health problems and to provide the effective oral health programs in community children's centers. Methods : The subjects were 464 teachers in community children's centers in Seoul, Incheon, Gyeonggi-do, Chungcheongbuk-do, and Jeollabuk-do. Results : There were differences between the regions(p<0.05) in oral health guidance among teachers in municipal and provincial community children's centers. The oral health education was considered as the most important thing in those who had more than 6 years career(71.8%), and followed by those having less than five years career(61.3%) and those having two years career(53.8%)(p<0.05). Although many children registered the program and newsletter was sent to the children's homes, but 70% of the children did not brush their teeth regularly(p<0.05). Regardless of region, gender, teaching career, and number of enrolled children, 90 percent or more people found that it necessary for community children's centers to collaborate with dental clinics. There were gender differences between the male and female(p<0.05). Male accounted for 42.4% response rate and female accounted for 36.4%. Approximately About 48.5% of male and 61.6% of female thought that the oral health program is the most important thing(p<0.05). Conclusions : The development of the customized oral health program is the most critical factor to the oral health behavior change in the children in the community children's centers and public dental clinics.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.3
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• pp.41-50
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• 2022

PURPOSE: This study sought to investigate the change in the satisfaction levels of healthcare students regarding clinical practice before and after the coronavirus disease 19 (COVID-19) outbreak. METHODS: This was a longitudinal survey using a structured questionnaire. The first survey was conducted before the COVID-19 outbreak in April 2018, and the second survey was conducted after the outbreak from May to June 2022. The questionnaire used before and after COVID-19 had the same content and was categorized into the following six factors to determine clinical practice satisfaction: practice guidance, practice environment, practice time, practice evaluation, interpersonal relationships, and effectiveness of practice. Before the COVID-19 pandemic, a total of 153 healthcare students (average age: 22.43 ± 1.47 years old), participated from 4 departments: nursing, physical therapy, occupational therapy, and dental hygiene. After COVID-19, 84 students (average age: 22.75 ± 2.87 years old), from the physical therapy, occupational therapy, nursing, and dental hygiene departments participated in the survey. RESULTS: Clinical practice satisfaction was evaluated considering the factors of practical guidance, practice environment, practice time, interpersonal relationships, and practical effects. It was observed that the satisfaction with clinical practice increased in nursing, physical therapy, occupational therapy, and dental hygiene students after COVID-19 compared to the situation before the outbreak. There was no difference seen in the practice time and practice evaluation factors in the occupational therapy department and in the practice time factor in the dental hygiene department before and after COVID. CONCLUSION: In clinical practice under the extremely constrained circumstances imposed by the COVID-19 pandemic, it seems that the emotional internal response is greater, and the satisfaction with clinical practice appears to be relatively higher than before the outbreak.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.34-39
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• 2015

KCG, responsible Agency of maritime SAR operation has been known to address the marine casualties well, however, it was criticized because KCG failed to take prompt and effective response to the recent Ferry disaster at the very early stage. In this regards, the authors analyze the characteristics of marine incident with historical data, and also review and examine the national SAR system focusing on SAR coordination and human resources to make recommendation and suggestion in order to minimize the loss of lives to future marine incidents. As a result, KCG shall augment its capabilities, inter alia, fast libeboats and rescue helicopters for prompt response to marine incidents at the coastal waters, and KCG shall re-adjust the establishment of Rescue Coordination Center to improve operational problems of current system in accordance with IMO guidance, KCG is required to introduce mandatory training, qualification and certificate system to enhance the professionalism of SAR personnel.

• Korean Journal of Health Education and Promotion
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• v.19 no.1
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• pp.45-58
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• 2002

This research was conducted to understand and analyze the physical awareness symptoms of college students and get fundamental research data essential to provide efficient student guidance and public health service at schools. The survey was carried out for 1 month from May 7th, 2001 to June 7th, 2001. The interviewees were 950 enrolled students at junior colleges in Daegu. 26.5% of them were men and 73.5% women. Among the surveyed, public health majors were 76.9%. Daytime students were 64.1 %, and the majority of the students, 42.8%, were atheistic. 56.0% of the students grew up in big cities, 22.2% in medium and small-sized cities, and 21.8% in farming and fishing communities. 66.1 % used public transportation. The majority of the students, 48.7%, answered that the satisfaction level for their majors was average. The result shows that the ocular fatigue was indicated as a greatest complaint, and the female students showed the higher complaint rate than the males. In the study of the complaining rate of physical symptoms by major, the public health majors showed the highest complaining rate in gasping when going up/down stairs, shoulder pain, a burning feeling on empty stomach, and leg/knee pain. On the other hand, the highest complaint factors for the technical majors were ocular fatigue and the feelings of heavy head. In the study of the complaining rate of physical symptoms by transportation, gasping during going up/down stairs and shoulder pain were most common, which were 52.2% and 36.0% respectively. In the study of the insecurity response distribution by transportation, college students who drive a car showed 3.8% and students using public transportation 3.7%. In the study of the insecurity response by subject satisfaction, students who answered dissatisfactory were 8.3%, average 3.9%, satisfied 3.0%. Therefore, it was concluded that students who were dissatisfied with their subjects showed the higher rate of insecurity response. it can be recommended that a school health education program regarding ocular fatigue and shoulder pain should be developed.

• Journal of The Korean Association For Science Education
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• v.37 no.4
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• pp.577-586
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• 2017

The purpose of this study is to try to structuralize the perception of the mothers of science-gifted elementary students using the concept mapping approach. The mothers who participated in this research had children who were 5th and 6th graders selected as science-gifted by a regional education office, a science high school and two national universities in a city. One of the authors interviewed 26 mothers, and extracted 50 general statements of their perceptions about the career path of their children. Ten mothers who participated in interviews sorted a shuffled pack of statement cards. The categorization of the statements into the dissimilarity matrix was carried out by SPSS multidimensional scaling analysis and hierarchical cluster analysis to generate a conceptual diagram. After that 140 mothers rated each statement using a Likert-type response scale from one to five. The result showed six clusters of parental views such as were 'Burden of private education, grades and going to the next grade,' 'Thinking about career guidance in gifted education and school,' 'Parental roles in child career education,' 'Difficulties in career guidance at home,' 'Demand for strengthening the parental capacity for career guidance,' and 'Demand for social support.' 'Demand for social support' obtained the highest sympathy from mothers of elementary science gifted.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.43-55
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• 2019

Smart phone based navigation applications are very useful in everyday life. Cost-effective and user friendly navigation can be provided to the user by many applications available in market. Using the Smart phone these navigation applications provide accurate navigation for outdoor locations. But providing an accurate navigation underground space such as subway station is still a challenge. It is hence more convenient and appropriate for mobility services if the visitors could simply view the guidance of the subway station on their mobile phone, wherever and whenever it is needed. This study develops a algorithm for indoor navigation with the help of Augmented Reality(AR) and QR marker code from the entrance to the train platform for users. This indoor navigation uses AR and QR maker codes for two purposes: to provide the user link to the subway station location and to provide the current guidance details to the user. This Smart phone algorithm that uses a smart phone optical tool to decode the QR marker to determine the location information and provide guidance to the AR without indoor Maps. This algorithm also provides a module to guide mobility vulnerable to the Barrier Free route to destination.