• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.54-63
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• 2005

Detection ranges of acoustic instruments mainly used for fisheries and their research are derived as the range bordered by a certain signal-to-noise ration (SNR) thershold. The SNR is depicted by several factors on transmitting and receiving, sound propagation, scattering by objects, and mainly self-ship noise. The detection ranges are shown for several fisheries instrument, such as echo sounder, quantiative echo sounder, and bio-telemetry system. The results can be used for designing the instruments, examining the capability of user's own instruments, and interpreting obtained data or echograms. Increasing transmitting power is not as effective for high frequencies as for low frequencies to increase the detection range. Comparison of volume backscattering strengths obtained by the quantitative echo sounder at several frequencies should be done within the same detection range. By applying the concept of the detection range for the bio-telemetry receiver beams, the number of the beams and the beamwidths can be determined.

• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.749-756
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• 2012

Objective: This study was performed to investigate the prevalence of musculoskeletal disorders of traditional Korean instrument player using a variety of traditional classical instruments: Gayageum, Geomungo, Ajaeng, Haegeum, Daegeum, Piri and Samul instruments. Background: A large percentage of instrument players have suffered from the musculoskeletal pain of each body parts. However, there is no research on the prevalence of musculoskeletal disorders of traditional Korean musical instrument players. Method: Through the focus group interview, a questionnaire to investigate musculoskeletal disorders was developed. The questionnaire consisted of four parts: demographic factors, performance factors, musculoskeletal disorders symptoms, musculoskeletal disorder experience. For the survey, 118 expert players participated. The data from the survey were analyzed by correlation analysis and chi-square analysis. Results: The symptoms of musculoskeletal disorders and the severe pain from musculoskeletal disorders were observed at neck, shoulder, back and knee. The musculoskeletal experience was statistically related to the factor of body height in Gayageum and Geomungo. In addition, the musculoskeletal experience in Geomungo was related to age and career. However, the musculoskeletal experience in Ajaeng and Haegeum was only related to the factor of hobby. The musculoskeletal experience in Daegeum and Piri was related to stretching. In addition, there was a statistical significance between the musculoskeletal experience and sex in Daegum. In Samul instruments, the statistical significance was observed at age, BMI, career and stretching. Conclusion: The symptoms of playing-related musculoskeletal disorders of traditional Korean musical players were prevalently observed at neck, shoulder, back and knee. In addition, these symptoms were related to the various demographic factors such as age, body height, BMI, career, sex, hobby and stretching. Application: The results of this study can be used as the preliminary data for preventing the musculoskeletal injuries of traditional Korean musical instrument players.

• Journal of the Korean Chemical Society
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• v.60 no.4
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• pp.267-275
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• 2016

Experiment is recognized as an important part in science and science education. Scientists do experiments for verifying or refuting theory and they take many forms to do experiments. One of the central goals of science education is to improve inquiry ability. So we have taken for granted that students engage in authentic inquiry and experiment which scientists carry out to research. But it is not always positive about discussions and opinions what school experiment and its role is in learning science and understanding about science. There is certainly a gap between experiments which scientists and students do even though there is a theoretical basis of school science experiment. In this study, we discussed how scientific inquiry and school inquiry are different, and what it means to use instrument in school science experiment. And as a case, we analyzed chemistry experiments in science textbook and manipulation level of instruments which were handled in chemistry experiments, we shed light on the meanings of experiments and instruments in school science inquiry based on the result of experiments and instruments analysis.

• Journal of Periodontal and Implant Science
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• v.51 no.5
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• pp.298-315
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• 2021

Purpose: Peri-implantitis therapy and implant maintenance are fundamental practices to enhance the longevity of zirconia implants. However, the use of physical decontamination methods, including hand instruments, polishing devices, ultrasonic scalers, and laser systems, might damage the implant surfaces. The aim of this systematic review was to evaluate the effects of physical decontamination methods on zirconia implant surfaces. Methods: A systematic search was conducted using 5 electronic databases: Ovid MEDLINE, PubMed, Scopus, Web of Science, and Cochrane. Hand searching of the OpenGrey database, reference lists, and 6 selected dental journals was also performed to identify relevant studies satisfying the eligibility criteria. Results: Overall, 1049 unique studies were identified, of which 11 studies were deemed suitable for final review. Air-abrasive devices with glycine powder, prophylaxis cups, and ultrasonic scalers with non-metal tips were found to cause minimal to no damage to implantgrade zirconia surfaces. However, hand instruments and ultrasonic scalers with metal tips have the potential to cause major damage to zirconia surfaces. In terms of laser systems, diode lasers appear to be the most promising, as no surface alterations were reported following their use. Conclusion: Air-abrasive devices and prophylaxis cups are safe for zirconia implant decontamination due to preservation of the implant surface integrity. In contrast, hand instruments and ultrasonic scalers with metal tips should be used with caution. Recommendations for the use of laser systems could not be fully established due to significant heterogeneity among included studies, but diode lasers may be the best-suited system. Further research-specifically, randomised controlled trials-would further confirm the effects of physical decontamination methods in a clinical setting.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.770-776
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• 2018

This study measured the energy recovery rate of each municipal waste incineration facility according to the revised energy recovery rate estimation method, which targeted four municipal waste incineration facilities (Unit No. 7). The results calculated by the measuring instruments were used for each factor to estimate the recovery rate, and the available potential of available energy was examined by analyzing the energy production and valid consumption. As a result of the low heating value, 2,540 kcal/kg was calculated on average when the LHVw formula was applied, which is approximately 116 kcal/kg higher than the average design standard of 2,424 kcal/kg. The energy recovery rate was calculated as 96.9% on average based on production and 67.5% based on effective consumption, and the analysis shows that approximately 29.4% energy can be used.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.108-116
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• 2018

Objectives: This study investigated to the analytical work environment, analyst's expert and status of analytical instrument in the designated organization's laboratory for measuring work environment, and carried out to ensure reliability of analytical results. Methods: This study was conducted by 114 analysts who work in designated organization's laboratory for measuring work environment. Information on the working environment and personal characteristics of the analysts were collected using a self-reported questionnaire and were analyzed using the SPSS program through analysis of frequency and t-test. Results: The speciality of subjects was occupational health(57.0%), environmental health(38.6%) and environmental engineering(4.4%), and they had a higher level of academic ability than workers in other industries. Analysts had to handle a large number of sample analysis and many tasks other than analytical work. The analysts answered that it was difficult to analyze organic substances than inorganic substances, and the difficult parts were the analytical methods setting of new substances(55.3%), instrument analysis(24.6%) and principle of analysis(23.7%). Analytical instruments mainly have legally required instruments. The difficulty of the analysis is solved from the senior analyst in the laboratory and analytical information is mainly exchanged through seminar organized by the Association of Occupational Health Analysts. The analysts who are planning to move or considering the company were 48.2%, and the reasons for moving the company were difficult to work(14.0%), low salary(9.6%), employment type(8.8%) and job stress(7.0%). Conclusions: The conclusions of our study were that it was possible to secure reliability by solving the problems such as implementing professional education to improve expertise of analysts, strengthening analytical instruments through institutional improvement and improving work environment.

• Korean Journal of Adult Nursing
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• v.27 no.4
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• pp.428-437
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• 2015

Purpose: The aim of this study was to describe health status and to identify the factors related to health behavior in older adults in South Korea. Methods: A cross-sectional survey was conducted with a convenience sample of 186 older people (mean age =68.2yrs, 65.1% Female) registered at one senior center. Data were collected by self-report questionnaires or through face to face interview. The instruments were the Modified Health Behavior Assessment Scale, Stanford Research Instruments for Chronic Disease, Self-Efficacy, SOF Frailty Index and Quality of life questionnaire. The data were analyzed using t-test, ANOVA, Pearson's correlation, and stepwise multiple regression. Results: 58.6% older adults perceived their health status positively. Education level and economic status were significantly related to health behaviors of older adults. Self-rated health, sleep, stress, quality of life, health distress, depression, and frailty were significantly correlated with the health behaviors of older adults. Frailty, education level, and sleep disturbance were the significant factors predicting the health behaviors. Conclusion: The findings from this study suggest that nurses should take into consideration education level of older adults to promote their health behaviors and health promotion program which focuses on maintaining the quality of sleep and preventing frailty.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.56.4-57
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• 2015

We present the optical design and a sensitivity analysis for a wide field of view (FOV) instrument operating at UV and IR wavelengths. The ongoing investigation is performed in collaboration with Omnisys Instruments (Sweden) and focuses on a telluric-limb-viewing instrument that will fly in a low Earth orbit to study mesospheric wave structures over a wide range of horizontal scales in the altitude range 80 - 100 km. The instrument has six wavelength channels which consist of 4 channels of IR and 2 of UV. We are proposing an optical design based on three mirror aplanatic off-axis reflective system. The entrance pupil diameter and effective focal length are 45 mm and 270 mm, respectively. The FOV is $5.5^{\circ}{\times}1^{\circ}$ and the secondary mirror is set for stop. The optical specification is required to have an encircled energy of at least 80 % within a diameter of 21 um. We performed sensitivity analysis for the longest wavelength of 772 nm in consideration of the diffraction limit of system. The results show that tolerance limits for positions and angles of the mirrors are not very sensitive compared with typical error budgets of manufacturing and assembling process. The secondary mirror has the most sensitive tolerance for surface figure of 250 nm in root-mean-square.

• Korean Journal of Health Education and Promotion
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• v.32 no.4
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• pp.93-108
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• 2015

Objectives: The purpose of this study was to investigate the current state of health literacy research and to explore the directions of improvement health literacy in Korea. Methods: A review of literature was conducted via an electronic database and citation tracking reference. A total of 173 articles were identified, where and then 41 articles were selected for review that met the inclusion criteria. Two authors independently reviewed the articles using the matrix table and together examined together the three aspects of the studies: research methods, health literacy instrument, and results. Results: Most of the articles were descriptive-correlation studies, but there were one intervention study and six methodology studies that were developing health literacy measures and instrument related items and etc. More troubling sufficient samples and sampling methods were lacking at the population level. The validity of the used health literacy instruments was not sufficient reported. Conclusions: Health literacy instruments need to be validated in various population and contexts. Additionally, effective strategies to improve health literacy included teach-back, pictogram, and decision aids need to be tested in Korean health care system.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.82-92
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• 2021

Nakdong technique is an unfamiliar scorching treatment using an iron heated in a kiln over 1000℃. It is a typical convention in Asian countries to treat Nakdong on the surface of paulownia species. The scorching treatment changes the surface characteristics as well as the color of the wood. This study focused on the effects of functional features such as water resistance, anti-mold, anti-termite, and sound improvement because this treatment is usually used on paulownia wood-bodied musical instruments surface. It took 28'57" for Nakdong-iron treated surface to absorb a droplet of water. The absorbance time of iron treated surface was longer than that of torch treated one. There was no noticeable effect on the anti-mold test. On the anti-termite test, there was nearly 3% more mean mass loss on the torch samples than controlled and iron treated ones. In examining the sound radiation coefficient before and after Nakdong treatment, the Nakdong-iron treated surface showed an increase in the average value of 1.2 m4/kg s, which means that it has sound quality improvement. Through this research, the Nakdong technique results are expected to be used as basic-data for further research and give a practical idea for using the traditional treatment method on the wood surface.