• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.64.2-64.2
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• 2019

It is known that lights scattered by comets and asteroids are partially polarized. From polarimetric observations of those objects, we can investigate physical properties, such as albedos, sizes of cometary dust particles and regolith of asteroids. Since the polarization degrees of those objects highly depend on their phase angles (Sun-object-observer's angles), long-term monitoring observations are required. Moreover, comets show unforeseeable activations (i.e., outbursts) which need follow-up observations to understand the mechanism. In order to realize such monitoring and transient observations, we installed the Triple-Range Imager and POLarimeter (TRIPOL) on the 61cm telescope of Seoul National University (Hereafter, SNU) Gwanak campus. With this combination, we can obtain g', r', i' bands photopolarimetric images simultaneously with $8.0^{\prime}{\times}8.0^{\prime}$ field of view and pixel resolution of 0.94" pixel-1. Here, we make a presentation regarding the photometric and polarimetric performances of TRIPOL on the SNU 61cm telescope. In addition, we introduce initial polarimetric results of asteroid and comets with the instruments. First, we determine the limiting magnitudes (defined as magnitudes for S/N=5) of $15.17{\pm}0.06$ (g'-band), $15.68{\pm}0.01$ (r'-band), $16.24{\pm}0.03$ (I'-band), respectively, with total 240-seconds exposure (four 60-seconds exposure images, each was taken at different rotation angle for the half-wave plate). Second, we found that the instrumental polarization is negligibly small, ($-0.32{\pm}0.04%$ in the g', $-0.36{\pm}0.05%$ in the r' and $-0.21{\pm}0.04%$ in the i'-bands), while the polarization efficiencies are large enough to maximize the performance (i.e., $97.52{\pm}0.03%$ in the g', $98.83{\pm}0.02%$ in the r' and $99.15{\pm}0.02%$ in the i'-bands). With the instruments, we made observations of three Jupiter-family comets, 21P/Giacobini-Zinner, 38P/Stephan-Oterma, and 46P/Wirtanen and plan to observe one near-Earth asteroid, (433) Eros, on a trial basis. Especially for comets, we discriminate signals from dust and gas to eliminate gas contamination, which are known to change observed degree of linear polarization, using multi-band images. We confirm that the phase angle dependency of these comets are consistent with previous observations, probably because polarimetric property of Jupiter-family comets are broadly homogeneous unlike asteroids. We will also describe future observation plans using TRIPOL and SNU 61cm telescope.

• Journal of Korean Medical Ki-Gong Academy
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• v.20 no.1
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• pp.15-67
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• 2020

Objective : The purpose of this study is to identify the trends of vibration(or wave) therapy in Korea, to actively utilize vibration(or wave) therapy, and to help research activities of vibration therapy in Korean Medicine. Methods : The following Korean words "진동기", "진동요법", "진동운동", "진동치료", "파동요법", "파동운동", "파동치료" were searched on three specialized search sites (RISS, NAL, DBpia). Trends of vibration therapy were analyzed through the selected researches suitable for this study among these searched researches in an overview format. Results : 1. A total of 8,116 studies were searched and a total of 365 studies were finally selected 2. From 2000 to 2019, when research began to increase in earnest, there were 17.45±10.28 studies per year, and the AGR(Average Annual Growth Rate) was 11.92%. 3. In the main field of research, the 'Medicine and Pharmacy' was the largest with 147(40.16%) studies. In the Middle Field, the 'Kinesiology' was the largest with 99(27.05%) studies. In the study design, 'RCT(Randomized Controlled trial)' was the largest with 138(47.75%) studies. In the Age Group, 'Youth' was the largest with 126(48.84%) studies. 4. The average of the number of participants was 24.90±17.44. 5. The most used Intervention was the 'WBV(Whole Body Vibration)' with 177(61.25%) studies. 6. The average of Intervention Period was 5.99±4.14 weeks, while the maximum was 36 weeks. 7. The journal that published the most research papers is 'K. J. of Sports Science(체육과학연구;13)', and the society is 'Rehabilitation Engineering And Assistive Technology Society of Korea(한국재활복지공학회; 14)'. The University that published the most dissertations is 'Sahmyook University(11)'. 8. The authors who published the most studies are Ju-Hwan O(8) as the main author and Tae Kyu Kwon(18) as the co-author (including the thesis Director). In an integrated analysis of the authors and co-authors, Tae Kyu Kwon published the most numerous studies(19) Conclusions : 1. The study of vibration or wave therapy has been increasing noticeably every year. 2. The major academic Fields studying vibration or wave therapy are the 'Kinesiologic Field', 'Physical Therapy Field', and 'Biomedical Engineering Field'. 3. The most chosen method of study design on vibration or wave treatment was 'RCT', and there was no significant change in the annual presentation rate. 4. Types of vibration or wave therapy could be classified as 'LVS(Local Vibration Stimulation)', 'WBV(Whole Body Vibration)', 'MV(Micro Vibration)', 'BV(Bio Vibration)' and 'SWV(Sound Wave Vibration)', and the study on Whole Body Vibration is most active. 5. Most of the studies of vibration or wave therapy were on musculoskeletal systems, but there were very few studies on internal diseases.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.227-238
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• 2022

This study is the case of non-face-to-face teaching-learning in the subject of "Research and Guidance on Early Childhood Materials" in the pre-child teacher training program. The study conducted a non-face-to-face teaching-learning model for 18 students at B University in region C who took lectures on 'Research and Guidance on Early Childhood Materials' in the first semester of 2021. As a non-face-to-face teaching-learning model, it consisted of video lectures, real-time zoom classes, and various forms of 'communication' through frequent feedback and interaction and 'participation'. As a teaching-learning strategy for the participation of pre-service early childhood teachers, comment on questions related to early childhood materials, in-depth reflection on early childhood materials through writing reflective journals and observation reports, and step-by-step presentation of making childhood materials plans, processes, and results were carried out. As a result of exploring the experience of making early childhood materials for pre-service early childhood teachers, factors such as "growth experience through trial and error," "thinking from child's point of view", "Increase efficiency and reduce burden through communication", "Process rather than result" and "The importance of communication and interaction in non-face-to-face classes"

• Proceedings of the KSPS conference
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• 1997.07a
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• pp.176-178
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• 1997

To make a long story short I made up my mind to experiment with a multimedia approach to my classroom presentations two years ago because my ways of giving instructions bored the pants off me as well as my students. My favorite ways used to be sometimes referred to as classical or traditional ones, heavily dependent on the three elements: teacher's mouth, books, and chalk. Some call it the 'MBC method'. To top it off, I tried audio-visuals such as tape recorders, cassette players, VTR, pictures, and you name it, that could help improve my teaching method. And yet I have been unhappy about the results by a trial and error approach. I was determined to look for a better way that would ensure my satisfaction in the first place. What really turned me on was a multimedia CD ROM title, ELLIS (English Language Learning Instructional Systems) developed by Dr. Frank Otto. This is an integrated system of learning English based on advanced computer technology. Inspired by the utility and potential of such a multimedia system for regular classroom or lab instructions, I designed a simple but practical multimedia language learning laboratory in 1994 for the first time in Korea(perhaps for the first time in the world). It was high time that the conventional type of language laboratory(audio-passive) at Hahnnam be replaced because of wear and tear. Prior to this development, in 1991, I put a first CALL(Computer Assisted Language Learning) laboratory equipped with 35 personal computers(286), where students were encouraged to practise English typing, word processing and study English grammar, English vocabulary, and English composition. The first multimedia language learning laboratory was composed of 1) a multimedia personal computer(486DX2 then, now 586), 2) VGA multipliers that enable simultaneous viewing of the screen at control of the instructor, 3) an amplifIer, 4) loud speakers, 5)student monitors, 6) student tables to seat three students(a monitor for two students is more realistic, though), 7) student chairs, 8) an instructor table, and 9) cables. It was augmented later with an Internet hookup. The beauty of this type of multimedia language learning laboratory is the economy of furnishing and maintaining it. There is no need of darkening the facilities, which is a must when an LCD/beam projector is preferred in the laboratory. It is headset free, which proved to make students exasperated when worn more than- twenty minutes. In the previous semester I taught three different subjects: Freshman English Lab, English Phonetics, and Listening Comprehension Intermediate. I used CD ROM titles like ELLIS, Master Pronunciation, English Tripple Play Plus, English Arcade, Living Books, Q-Steps, English Discoveries, Compton's Encyclopedia. On the other hand, I managed to put all teaching materials into PowerPoint, where letters, photo, graphic, animation, audio, and video files are orderly stored in terms of slides. It takes time for me to prepare my teaching materials via PowerPoint, but it is a wonderful tool for the sake of presentations. And it is worth trying as long as I can entertain my students in such a way. Once everything is put into the computer, I feel relaxed and a bit excited watching my students enjoy my presentations. It appears to be great fun for students because they have never experienced this type of instruction. This is how I freed myself from having to manipulate a cassette tape player, VTR, and write on the board. The student monitors in front of them seem to help them concentrate on what they see, combined with what they hear. All I have to do is to simply click a mouse to give presentations and explanations, when necessary. I use a remote mouse, which prevents me from sitting at the instructor table. Instead, I can walk around in the room and enjoy freer interactions with students. Using this instrument, I can also have my students participate in the presentation. In particular, I invite my students to manipulate the computer using the remote mouse from the student's seat not from the instructor's seat. Every student appears to be fascinated with my multimedia approach to English teaching because of its unique nature as a new teaching tool as we face the 21st century. They all agree that the multimedia way is an interesting and fascinating way of learning to satisfy their needs. Above all, it helps lighten their drudgery in the classroom. They feel other subjects taught by other teachers should be treated in the same fashion. A multimedia approach to education is impossible without the advent of hi-tech computers, of which multi functions are integrated into a unified system, i.e., a personal computer. If you have computer-phobia, make quick friends with it; the sooner, the better. It can be a wonderful assistant to you. It is the Internet that I pay close attention to in conjunction with the multimedia approach to English education. Via e-mail system, I encourage my students to write to me in English. I encourage them to enjoy chatting with people all over the world. I also encourage them to visit the sites where they offer study courses in English conversation, vocabulary, idiomatic expressions, reading, and writing. I help them search any subject they want to via World Wide Web. Some day in the near future it will be the hub of learning for everybody. It will eventually free students from books, teachers, libraries, classrooms, and boredom. I will keep exploring better ways to give satisfying instructions to my students who deserve my entertainment.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.259-265
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• 1993

Between January 1985 and July 1992, 52 patients with locally advanced nasopharyngeal carcinoma were studied retrospectively for the effectiveness of sequential chemotherapy and radiation therapy. The male to female ratio was 3.3:1 with a median age of 41 years. Forty patients had squamous cell carcinoma and the remaining 12 had undifferentiated carcinoma. Seven patients had stage III disease and the remainder had stage IV disease at time of presentation. All patients were treated two courses of chemotherapy followed by radiation therapy. Chemotherapy consisted of either CVB (cisplatin, vincristine and bleomycin) or CF (cisplatin and 5-FU). Total radiation dose to the primary site ranged from 6000 cGy to 7500 cGy. Neck nodes were given booster treatment to maximum of 7000 cGy, depending on the extent of disease. Local control, overall survival and disease-free survival rates were analyzed. The complete response (CR) rate to chemotherapy was $15\%$ and the partial response (PR) rate was $46\%,$ for overall major response rate of $61\%.$ The CR rate was $87\%$ after radiation therapy. Median follow-up time was 51 months. The overall survival and disease-free survival rates at 36 months were $54\%\;and\;49\%,$ respectively. Median time to relapse was 15 months. The patterns of initial relapse in CR patients was as follows: locoregional failure only, 12 patients; distant metastasis only,11: both,2. Cox's multivariate regression model revealed that nodal status was the single most important independant prognostic factor influencing disease-free survival (p=0.001). Comparision of these results with other published reports with radiation therapy alone showed that a high rate of initial response to chemotherapy did not translate into local control or survival. At present time radiation therapy alone remains the standard treatment for locoregional cancer of the nasopharyngeal cancer. More controlled clinical trials must be completed before acceptance of chemotherapy as a part of treatment of advanced nasopharyngeal carcinoma.

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.11-22
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• 2002

This study investigated the effects of mild mental imagery inducing pleasantness or unpleasantness and cognitive mental arithmetic task on skin conductance level. Subjects were f undergraduates(male 5, female 4). They were given the list of the words and asked to write down the liked objects and the disliked ones freely associated with these words. Among these objects the most-liked one and the most disliked one were selected as the self-induced mental imageries. Data-collection procedures were as follows ; first baseline, pleasant imagery, 2nd baseline, unpleasant imagery, finally 3rd baseline, and mental arithmetic task subtracting continuously 7 from the number 500. During these trials, the SCLs were recorded every 10 seconds. The results indicated that there were nonsignificant differences between the 3 trial-baselines ot each condition. This suggested that unlike the procedures used in the previous studies, our procedures would give the stability of the baseline level necessary for the comparison of the effects of several stimuli. Also, the level of skin conductance in mental arithmetic condition was significantly higher than that of the emotional mental imagery. This suggested the possibility that mental arithmetic task would gave rise to the higher physiological arousal in comparison to mental imageries. Overall, it was suggested that the procedures and the stimulus presentation methods used in this preliminary study could be useful for the data-collection techniques for The future study. Implications for the future study were presented.

• Journal of Elementary Mathematics Education in Korea
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• v.9 no.2
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• pp.85-110
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• 2005

The purpose of this study is to examine the characteristics of visual representation used in problem solving process and examine the representation types the students used to successfully solve the problem and focus on systematizing the visual representation method using the condition students suggest in the problems. To achieve the goal of this study, following questions have been raised. (1) what characteristic does the representation the elementary school students used in the process of solving a math problem possess? (2) what types of representation did students use in order to successfully solve elementary math problem? 240 4th graders attending J Elementary School located in Seoul participated in this study. Qualitative methodology was used for data analysis, and the analysis suggested representation method the students use in problem solving process and then suggested the representation that can successfully solve five different problems. The results of the study as follow. First, the students are not familiar with representing with various methods in the problem solving process. Students tend to solve the problem using equations rather than drawing a diagram when they can not find a word that gives a hint to draw a diagram. The method students used to restate the problem was mostly rewriting the problem, and they could not utilize a table that is essential in solving the problem. Thus, various errors were found. Students did not simplify the complicated problem to find the pattern to solve the problem. Second, the image and strategy created as the problem was read and the affected greatly in solving the problem. The first image created as the problem was read made students to draw different diagram and make them choose different strategies. The study showed the importance of first image by most of the students who do not pass the trial and error step and use the strategy they chose first. Third, the students who successfully solved the problems do not solely depend on the equation but put them in the form which information are decoded. They do not write difficult equation that they can not solve, but put them into a simplified equation that know to solve the problem. On fraction problems, they draw a diagram to solve the problem without calculation, Fourth, the students who. successfully solved the problem drew clear diagram that can be understood with intuition. By representing visually, unnecessary information were omitted and used simple image were drawn using symbol or lines, and to clarify the relationship between the information, numeric explanation was added. In addition, they restricted use of complicated motion line and dividing line, proper noun in the word problems were not changed into abbreviation or symbols to clearly restate the problem. Adding additional information was useful source in solving the problem.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1252-1264
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• 1998

Background : Patients with established ARDS have a mortality rate that exceeds 50 percent despite of intensive care including artificial ventilation modality, Mortality has been associated with sepsis and organ failure preceding or following ARDS ; APACHE II score ; old age and predisposing factors. Revised ventilator strategy over last 10 years especially at ARDS appeared to improve the mortality of it. We retrospectively investigated 40 ARDS patients of respiratory-care unit to examine how these factors influence outcome. Methods : A retrospective investigation of 40 ARDS patients in respiratory-care unit with ventilator management over 46 months was performed. We investigated the clinical characteristics such as a risk factor, cause of death and mortality, and also parameters such as APACHE II score, number of organ dysfunction, and hypoxia score (HS, $PaO_2/FIO_2$) at day 1, 3, 7 of severe acute lung injury, and simultaneously the PEEP level and tidal volume. Results : Clinical conditions associated with ARDS were sepsis 50%, pneumonia 30%, aspiration pneumonia 20%, and mortality rate based on the etiology of ARDS was sepsis 50%, pneumonia 67%(p<0.01 vs sepsis), aspiration pneumonia 38%. Overall mortality rate was 60%. In 28 day-nonsurvivors, leading cause of death was severe sepsis(42.9%) followed by MOF(28.6%), respiratory failure(19.1 %), and others(9.5%). There were no differences in variables of age, sex, APACHE II score, HS, and numbers of organ dysfunction at day 1 of ARDS between 28-days survivor and nonsurvivors. In view of categorized variables of age(>70), APACHE II score(>26), HS(<150) at day 1 of ARDS, there were significant differences between 28-days survivor and nonsurvivors(p<0.05). After day 1 of ARDS, the survivors have improved their APACHE II score, HS, numbers of organ dysfunction over the first 3d to 7d, but nonsurvivors did not improve over a seven-day course. There were significant differences in APACHE II score and numbers of organ dysfunction of day 3, 7 of ARDS, and HS of day 7 of ARDS between survivors and nonsurvivors(p<0.05). Fatality rate of ARDS has been declined from 68% to less than 40% between 1995 and 1998. There were no differences in APACHE II score, HS, numbers of organ dysfunction, old age at presentation of ARDS. In last years, mean PEEP level was significantly higher and mean tidal volume was significantly lower than previous years during seven days of ARDS(p<0.01). Conclusions : Improvement of HS, APACHE II score, organ dysfunction over the first 3d to 7d is associated with increased survival Decline in ARDS fatality rates between 1995 and 1998 seems that this trend must be attributed to improved supportive therapy including at least high PEEP instead of conventional-least PEEP approach in ventilator management of acute respiratory distress syndrome.