• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.279-290
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• 2023

Recently, as wind farms using wind power as new and renewable energy have been installed nationwide, noise problems have emerged. The environmental impact assessment and post-environmental impact assessment also require the measurement of background noise and low-frequency noise for wind farms, especially by applying the living noise measurement method according to the low-frequency noise management guidelines issued by the Ministry of Environment in 2018. Due to the nature of wind power generators that generate loud noise in high winds, noise measurement should be made at high winds, but when wind speed increases, wind noise increases and living noise and low-frequency noise are not properly evaluated. Therefore, the type of noise generated by wind power generators was confirmed, and matters to be considered when measuring wind noise such as wind noise were confirmed.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.177-184
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• 2013

Calcium hydroxide mixture medicaments can nearly be considered to be the ideal primary tooth filling material. However, long-term application of calcium hydroxide combinations as an intra canal medicament softens dentin. The aim of this study was to evaluate the effect of calcium hydroxide on the microhardness of root dentin of primary tooth. For the study, 60 extractedprimary incisors were divided into 3 groups (no medicament, calcium hydroxide/iodorform mixture, and calcium hydroxide/distilled water mixture). After the cleansing and shaping of canals, calcium hydroxide medicaments were applied and stored for different periods of time (1, 7, 30, 90 days). The root was horizontally sectioned into 2 mm thick specimens and the microhardness was measured using Vickers microhardness tester. The results were as follows : Root dentin microhardness of primary teeth decreased with long term exposure to calcium hydroxide medicaments according to the experimental period and showed statistically significance (p < 0.05). Root dentin microhardness of primary tooth filled with calcium hydroxide mixed with distilled water showed more decrease than filled with Vitapex and showed statistically significance (p < 0.05). Root dentin microhardness of a control group without exposure to calcium hydroxide decreased according to the experimental period and showed statistically significance (p < 0.05).

• Journal of Science Education
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• v.46 no.1
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• pp.93-108
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• 2022

The purpose of this study is to develop a STEAM program that can be used in the high school credit system to be fully implemented in 2025, and to examine its validity and effectiveness. The STEAM program analyzed the 2015 revised curriculum centering on science, technology, and engineering through the 2015 revised curriculum analysis, and then selected the five latest issues: hydrogen fuel, climate crisis, data science, appropriate technology, and barista. In accordance with this self-developed program development format (frame), it was developed for seven months through a process of group deliberation. The draft of the STEAM program for 29 sessions of five types, developed to indirectly experience the career path and occupation of high school students, was verified through consultation with 2 STEAM education experts. It was applied at five different high schools for a pilot implementation. As a result of the pilot application, it was confirmed that the students' STEAM attitude significantly improved in the post-test than the pre-test, and the students' high satisfaction with the program was confirmed. In addition, through an interview with the pilot application teacher, it was positively evaluated that 'the content and level of the program are suitable and through experience solving real-life problems, you can apply the content knowledge of related subjects and have an opportunity to experience careers.' Based on the results of the pilot application, the high school credit system STEAM program for students and teachers was finally completed in 29 lessons of five types. Through this study, the development and operation of the next-generation STEAM program that can be applied in the high school credit system should be actively developed, and a plan to improve teachers' professionalism so that the high school credit system can be established and operated properly for blended classes triggered by COVID-19. The necessity of design was suggested. This study is expected to be used as basic data for the development and operation of STEAM programs in the high school credit system, which will be fully implemented in 2025.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.100-105
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• 2010

This study was conducted to establish a method to analyze azodicarbonamide (ADA) in wheat flour. A new method using high performance liquid chromatography (HPLC) was developed for the determination of ADA in wheat flour. The recovery rate was 91.93~97.54%. The limit of detection for ADA was 0.02 mg/kg and the limit of quantification was 0.05 mg/kg. The monitoring results for ADA contents using the established methods showed that it was detected as the low value of 0.95 mg/kg in one of 51 flour samples (detection rate : 2%), but not detected in 59 bakery samples. The detected ADA level was suitable to its usage standard, compared to the standard (45 mg/kg). Although the detection rate was very low, the established analytical method of ADA will contribute to the management of ADA in processed foods such as wheat flour and bakery.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.713-722
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• 1996

Poor long term patient survival (60% at 2 years) in lung allograft recipients are mainly due to rejection and complications associated with the use of nonspecific immunosuppressants. Better means to achieve waft acceptance is desperately needed. 1 have investigated whether mixed allogeneic chimerism in the form of bone marrow stem cell engraftment would induce donor-specific tolerance for lung allografts. Fisher (F344) and Wistar Forth (WF)rats were lethally irradiated (1100c0y) and reconstituted with a mixture of T-cell depleted syngeneic and allogeneic bone marrow (F344+WFIWF, ACI +F344- F344). After Mixed chimerism was documented by peripheral blood Ipnphocyte typing at 28 days, orthotopic left single lung transplantation was performed, using donor-s ecific or third party allografts. No immunosuppressants were administered. Graft rejection was monitored by chest rentgenography, and con- firmed by histology Mixed chimeric rats accepted lung allografts permanently, and it was not strain specific effect. Tolerance was all or none phenomenon which had nothing to do with the percentage of chimerlsm. Mixed chimeras rejected third party allografts in less than 10 days, a time course similar to that of unmanipulated controls. No acute or chronic rejection was observed in donor specific grafts more than 150 days posttransplant. These data suggest that mixed chimerism in the form of bone marrow stem cell engraftment results in stable, systemic donor-specific transplantation tolerance for lung allografts.

• Spatial Information Research
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• v.23 no.3
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• pp.123-132
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• 2015

Recently both the importance and the interests of field-experience learning have kept increasing since the Education of Ministry encourages students to take a field-experience learning with the self-driven and creative education as the main issue in the 7th revised education curriculum in 2009. As the importance of field-experience learning goes up continuously, not only the release of its related mobile applications is increasing, but also a variety of researches for supporting the field-experience learning are ongoing. In this research we perform two things. First, we define the basic concept of authoring tool for which support the field-experience learning based on its characteristics and user requirements analysis. We confirmed that the authoring tool for the field-experience learning has to 1) support all activities that happen in pre-field, field-experience and post-field phases, 2) be possible to write the location-based field work, 3) have the authoring function which reflects the characteristics of curriculum such as history, science and geography, etc. that the field learning can be realized, 4) be designed as the structure that the results of inquiring activity after the field experience activity can be reused. Second, we create a conceptual design after confirming the authoring tool.

• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.19-33
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• 2019

This paper examines the perception of Korean phonemes by Egyptian learners of Korean and presents the learnability gradient of Korean consonants and vowels through High Variability Phonetic Training (HVPT). 50 Egyptian learners of Korean (27 low proficiency learners and 23 high proficiency learners) participated in 10 sessions of HVPT for Korean vowels, word initial and final consonants. Participants were tested on their identification ability of Korean vowels, word initial consonants, and syllable codas before and after the training. The results showed that both low and high proficiency groups did benefit from the training. Low proficiency learners showed a higher improvement rate than high proficiency learners. Based on the HVPT results, a learnability gradient was established to give insights into priorities in teaching Korean sounds to Egyptian learners.

• Education of Primary School Mathematics
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• v.22 no.4
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• pp.239-259
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• 2019

The 2015 revised mathematics curriculum specified software education as a mandatory curriculum amid a trend in which the software environment was extended to daily life due to the fourth industrial revolution. It also calls for a paradigm shift in lessons that incorporate learning and evaluation by specifying a process-oriented assessment. This study focused on addition and subtraction classes based on computational thinking skills that integrate mathematics learning and evaluation. Two fourth grade classes of elementary schools in Seoul were selected to conduct a pre- and post- test of metacognition and mathematics achievement through quantitative research. Also, a mixed study was conducted to analyze students' activities and opinions in parallel. The results of the study confirmed that the computational thinking-based classes, which incorporate mathematics learning and evaluation, had a positive effect on the metacognition of elementary school students and the improvement of their achievement scores. In addition to those identified in this study, further studies on other factors are proposed.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.101-104
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• 2008

Inspection of Ship for the Prevention of Marine Pollution, that is After checking system of Marine Pollution according to the 115th of the Law of the Marine Environmental Management, that has been Marine Environmental Surveillant working on the Korea Coast Guard, aboard a ship, inspect to the normal operating q the Marine pollution Prevention Equipment and to Keep, Recording and Management well of All Recording Book of Marine Pollution Materials and to Check the treat results that dust oil and waste mater and discharge from ship during 30years, from 1978 to 2007 year. We offered the new inspection system that the Self Monitoring System that is the ship owner and Captain Voluntary Management the Marine Pollution Equipment for the prevent the marine pollution for the Unburden the Economical Activities and Unbiased of Ship's Crew.

• Phonetics and Speech Sciences
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• v.15 no.4
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• pp.17-26
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• 2023

This study aimed to reveal how Vietnamese adult learners at three different proficiency levels perceive Korean word-initial obstruents and whether errors can be corrected through perceptual training. To this end, 105 Vietnamese beginner, intermediate, and advanced learners were given perceptual training on Korean word-initial. The training materials were created by actively utilizing Korean minimal pairs as natural stimuli recorded by native speakers. Learners in the experimental group performed five 20-40 minute self-directed perceptual training sessions over a period of approximately two weeks, while learners in the control group only participated in the pretest and posttest. The results showed a significant improvement in the perception of sounds that were difficult to distinguish before training, and both beginners and advanced learners benefited from the training. This study confirmed that large-scale perceptual training can play an important role in helping Vietnamese learners learn the appropriate acoustic cues to distinguish different sounds in Korean.