• Journal of Periodontal and Implant Science
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• v.50 no.1
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• pp.56-66
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• 2020

Purpose: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device. Methods: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured. Results: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was -6.76 (-25.05 to 11.53, P<0.05). Conclusions: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.

• Child Health Nursing Research
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• v.21 no.1
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• pp.64-73
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• 2015

Purpose: This study was conducted to explore the professional identity of elementary school health teachers. Methods: In-depth interviews with fifteen elementary school health teachers were conducted from July 2010 to August 2012. Qualitative data collected by the researcher including transcription and field notes were analyzed through an adapted methodology based on the Grounded Theory of Strauss and Corbin. Results: Fifteen categories, 35 sub-categories and 120 concepts were obtained. The key category that was consistently maintained in identity formation was 'keeping themselves being a teacher providing nursing' which has three styles, 'focusing on health education', 'combining nursing and education' and 'focusing on providing nursing care'. Conclusion: Results of this study will provide basic information for preparing manuals regarding the range of activities in school health teachers' jobs, improving promotion and merit payment systems for school health teachers, creating support programs for them, and contributing to the formation and establishment of their professional identity.

• Geophysics and Geophysical Exploration
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• v.14 no.3
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• pp.220-226
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• 2011

In the elastic wave equations, both horizontal and vertical displacements are defined. Since we can measure both the horizontal and vertical displacements in field acquisition, these displacements compose a displacement vector. In this study, we propose a frequency-domain elastic waveform inversion technique taking advantage of the magnitudes of displacement vectors to define objective function. When we apply this displacement-vector objective function to the frequency-domain waveform inversion, the inversion process naturally incorporates the back-propagation algorithm. Through the inversion examples with the Marmousi model and the SEG/EAGE salt model, we could note that the RMS error of the solution obtained by our algorithm decreased more stably than that of the conventional method. Particularly, the density of the Marmousi model and the low-velocity sub-salt zone of the SEG/EAGE salt model were successfully recovered. Since the gradient direction obtained from the proposed objective function is numerically unstable, we need additional study to stabilize the gradient direction. In order to perform the waveform inversion using the displacementvector objective function, it is necessary to acquire multi-component data. Hence, more rigorous study should be continued for the multi-component land acquisition or OBC (Ocean Bottom Cable) multi-component survey.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.77-86
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• 2011

The advanced geotechnical information has been required to determine the accurate design parameters for complex construction. However, the Standard Penetration Test (SPT), which has low reliability, has been used to estimate the subsurface condition in the field. The objective of this paper is development and application of the Static-Dynamic penetrometer, which detects the resistances in soft clay, sand and rock. The energy losses according to the rod connection methods (perfect or non-perfect connection, and number rods) are experimentally evaluated. The reflection and transmission ratios are used to investigate the energy loss by a simulation. The static-dynamic cone penetrometer, in which the accelerometers and strain gauges are installed on the cone tip and the rod head, is used to estimate the energy loss during penetration by impacts. The experimental and simulation studies show that the transferred energy through rods with non-perfect connection dramatically decreases. Furthermore, the transferred energy on the rod head is not the same as that on the cone tip. This study demonstrates that the energy loss should be evaluated on the cone tip.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.1
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• pp.19-32
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• 2004

This study was conducted to evaluated musculoskeletal subjective symptoms and the degree of stress of industrial workers to present fundamental materials of preventive oriental medicine for improving their health and quality of life. During the medical examination with oriental medicine method, presence of subjective symptoms of musculoskeletal pain, Psychosocial Well-being Index(PWI) and life style were checked by using questionnaire method in 474 industrial workers. The collected data were analyzed with crosstabs, ANOVA and T-test. The results were as follows; 1. In general differences according to musculoskeletal subjective symptoms, education level of high school graduation had significantly higher distribution than that of below middle school or above university graduation in the pain present group. 2. In the musculoskeletal subjective symptoms and the degree of stress, all of Factor1, Factor2. Factor3, Factor4. and PWI had higher score in pain present group than in pain free group and the difference was statistically significant. 3. According to degree of stress and general character of subjects, single and education level of high school graduation had high score in Factor2, Factor3 and PWI. Factor1 and Factor3 was high in income group of low 1.49 million won. Factor2, Factor4, and PWI was high significantly in income group of 1.50 - 2.99 million won. In job type, manufacturing worker group had significantly high score in Factor3. 4. In degree of stress and life style difference, there was significant difference in PWI score in the field of alcohol chinking, smoking, exercise, obesity except sleeping hours. In the present study. as a result, it is found out that musculoskeletal subjective symptoms present group had higher score in psychosocial stress across the fields than symptom-free group and it is recommended that continuous studies on the relationship of job-related musculoskeletal disorders and psychosocial stress should be performed for improvement and prevention of mental and physical health of industrial worke

• 대한공업교육학회지
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• v.39 no.1
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• pp.227-246
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• 2014

The purpose of this study is to suggest the desirable direction toward the creative hand-on activities suitable for the characters of the technical high school students by examining the teachers' recognition of sub-factors of creative activities in technical high school and analysing whether the factors are properly utilized. Respondents of this study were 393 teachers at the Technical high school in South Korea. The questionnaire survey on the recognition of creative hand-on activities consisted of questions, which are importance and reflection, from 32 sections in 5 fields. The summary of the results through this study is as following. First, In the results of importance analysis of teachers in technical high school, in club activity field, 'the invention' of 'academic activity', 'film-art' in 'culture-art activity', 'challenge activity' in 'sports activity', 'school specialized major' in 'work practice activity', 'scout federation', 'Red Cross youth activity' in 'youth group activity' were seemed to be higher. Second, In the results of reflection analysis, it was found that the 'academy, culture-art', 'sports activity' fields were similarly reflected in importance thought by teachers in technical high school. However, for 'the work practice activity' and 'youth group activity', except 'the school specialized major', all fields are not properly reflected, independent of importance. For 'the work practice activity', analyses of importance and reflection seemed to be alike but for 'the youth group activity', there was a significant difference between them.

• Ecology and Resilient Infrastructure
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• v.2 no.2
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• pp.185-190
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• 2015

Greenhouse gas (GHG) emission from agricultural lands is recognized as one of important factors of global warming. The objective of this short communication was to evaluate the applicability of different soil GHG emission prediction models on agricultural systems in Korea. Four models, namely, DNDC, DAYCENT, EXPERT-N and COUP, were selected and the basic structure (e.g., components and sub-model), input variables, and output variables were compared. In particular, the availability and compilation of essential input variables were assessed. Major input variables needed for operating these predictive models were found to be available through database systems established by national organizations such as the Korea Meteorological Administration, the Korean Soil Information System, and the Rural Development Administration. However, in order to apply these models in Korea, it was necessary to calibrate and validate each of the models for the domestic landscape settings and climate conditions. In addition, field data of long-term monitoring of GHG emission from agricultural lands are limited and therefore should be measured.

• Journal of Science Education
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• v.35 no.1
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• pp.13-22
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• 2011

There is an increasing emphasis on science teaching in inclusion education setting, but still few research and practice in science education field including science teacher training course as well. It is well known that teaching efficacy of teacher is an important factor to influence teaching behavior and students' learning, but it is hard to find related studies about self-efficacy on teaching science for the disabled students. In this study pre-service science teachers' self-efficacy on science teaching for the disabled students was investigated and analyzed. For this a questionnaire consisted of 3 sub-scale like learning efficacy scale, teaching efficacy scale, and outcome expectancy scale was enacted to 97 pre-service science teachers. As a result, pre-service science teachers showed relatively low efficacy in teaching but showed positive learning efficacy and outcome expectancy. There was no meaningful difference in distribution of efficacy belief by gender, however the experience of teaching science for the disabled students made difference in outcome expectancy. From this study the implication for science teacher training course was inferred to meet the needs for science education in inclusion setting.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.169-175
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• 2003

For safe and easy disposal of prochloraz wastewaters after used as rice seed disinfectant in Korean farms, this experiment was carried out. By addition of several agricultural materials commonly utilizing in farmers, removal effect of prochloraz from waste solution was also investigated. When rice seeds after soaking in diluted prochloraz solution were rinsed with water several times, prochloraz was removed $9.2\sim10.6%$ at the first rinse and less than 3 % at the fourth rinse. A half life of prochloraz was $4\sim5$ days in aqueous system. Hydrolysis of prochloraz was more rapidly in alkali solution than neutral and acidic one at $25^{\circ}C$ and $35^{\circ}C$. By the irradiation under $5530J/cm^2$ using xenone lamp, prochloraz was photo-degraded to 87.7% in aqueous system. The removal efficiency of prochloraz by addition of several agricultural materials were as follows: 93.6% by lime, 90.7% by composed pig manure, 89.4% by activated charcoal, 78.0% by straw ash, 70.3% by sandy loam soil, 47.0% by zeolite and 24.1 % by rice straw. When prochloraz solution was sprayed on the field soil, it was dissipated upto 90% within 35 days.

• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.1057-1088
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• 2017

This research has attempted to conduct meta-analysis on 605 published papers in the field of socio-nuclear studies from 1957 to 2016 in Korea through network analysis of author-provided keywords. The findings lead to several straightforward conclusions. First, socio-nuclear studies including policy research have mostly been conducted by universities, while technology developments have been led by public organizations. Second, it is apparent that the Fukushima accident has provoked major engagement among social scientists in nuclear issues as the remarkable growth of the knowledge network after 2011 signify. Third, the research topics have been diversified as a result of growing multi-disciplinary research projects. Finally, there is between sub communities in the socio-nuclear knowledge network in terms of network properties. This article provides a stepping stone for future researchers with a wealth of information concerning the status of socio-nuclear studies. For policy makers, this meta-analysis is likely to provide guidance on what we need and do not need. It remains to be seen whether the socio-nuclear knowledge network in Korea is well-structured or not. provide an impetus for comparative studies with overseas cases in order to evaluate the network and its soundness.