• Journal of Science Education
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• v.38 no.3
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• pp.509-524
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• 2014

The purposes of this study were to develop a program utilizing learning strategies for underachieving middle school students in science and to identify the effectiveness of the program on the ability of using learning strategies and the improvement of science academic achievement. For this study, we developed the program of learning strategies consisting of eleven consecutive lesson plans focusing on the content of 2009 revised national science curriculum and applied the program to three underachieving students in science of 7th grade, who have weaker learning strategies that can be used for science study than other underachievers. After treatments, we analyzed the effectiveness of this program through science learning strategy tests, overall assessments, student-activity sheets, research logs, learning-transcription details, analysis of interviews with students, and observation of classes. According to this study, the enhancement of the ability of using learning strategies was limited because it was difficult for the students to change their fossilized strategies. On the other hand, their overall academic performance was considerably improved since the students became interested in studying science drawing on the learning strategies. Therefore, the program of learning strategies had a positive effect on improving the science underachievers' ability of using learning strategies and academic achievements.

• Korean Journal of Remote Sensing
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• v.35 no.6_1
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• pp.987-997
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• 2019

Recently the demand for drones is rapidly increasing, as developing Unmanned Aerial Vehicle (UAV) and growing interest in them. Compared to traditional satellite and aerial imagery, it can be used for various researches (environment, geographic information, ocean observation, and remote sensing) because it can be managed with low operating costs and effective data acquisition. However, there is a disadvantage in that only a small area is acquired compared to the satellite and an aircraft, which is a traditional remote sensing method, depending on the battery capacity of the UAV, and the distance limit between Ground Control System (GCS) and UAV. If remote control at long range is possible, the possibility of using UAV in the field of remote sensing can be increased. Therefore, there is a need for a communication network system capable of controlling regardless of the distance between the UAV and the GCS. The distance between UAV and GCS can be transmitted and received using simple radio devices (RF 2.4 GHz, 915 MHz, 433 MHz), which is limited to around 2 km. If the UAV can be managed simultaneously by improving the operating environment of the UAV using a Long-Term Evolution (LTE) communication network, it can make greater effects by converging with the existing industries. In this study, we performed the maximum straight-line distance 6.1 km, the test area 2.2 ㎢, and the total flight distance 41.75 km based on GCS through LTE communication. In addition, we analyzed the possibility of disconnected communication through the base station of LTE communication.

• The Korean Society of Law and Medicine
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• v.20 no.2
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• pp.261-285
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• 2019

The essential policy of suicide prevention is to continuously manage and treat suicide attempted people through data base related to suicide retry rate and follow-up study report. In Korea, only few people are allowed to follow-up by the Personal Information Protection Act. As a result, the research participation rate and the service participation rate are rather low, so that the research participants is limited to a part of the suicide attempted people. Therefore, the policy proposals to be improved in the Ministry of Health and Welfare Act were examined comparatively in order to increase the practical utilization of the suicide prevention about Article 14 and Article 20 of the Suicide Prevention Act. As a criterion for policy improvement, measures for non-discrimination of information to be considered in terms of technical and ethical dimensions and non-profit research and medical information for medical purposes were suggested. In addition to the severity of the suicide, the suicide risk was assessed and the criteria for the objective assessment of the follow-up observation were considered in consideration of the severity of the suicide.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.650-657
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• 2011

The object of this study was to obtain acute information (single oral dose toxicity) of Taraxaci Herba (Dried total parts of Taraxacum platycarpum. H.Dahlstedt (Compositae)), has been traditionally used in Korean medicine for treating various inflammatory diseases. In order to observe the 50% lethal dose (LD 50), approximate lethal dosage (ALD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2,000, 1,000, 500 mg/kg according to the recommendation of Korea Food and Drug Administration Guidelines. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after single oral treatment of Taraxaci Herba aqueous extracts according to KFDA Guidelines with organ weights and histopathological observations of 12 types of principle organs. After single oral treatment of Taraxaci Herba aqueous extracts, we could not find any mortality and toxicological evidences up to 2,000 mg/kg treated group, the limited dosages in rodents at body and organ weights, clinical signs, gross and histopathological observations. Except for slight soft feces, which were detected in male mice treated with 2,000 mg/kg of Taraxaci Herba aqueous extracts at 1 day after end of treatment. The results obtained in this study suggest that the LD 50 and ALD of Taraxaci Herba aqueous extracts in both female and male mice after single oral treatment were considered as over 2,000 mg/kg because no mortalities were detected up to 2000 mg/kg that was the highest dose recommended by KFDA and OECD. However, it also observed that the possibility of digestive disorders, like diarrhea when administered over 2,000 mg/kg of Taraxaci Herba aqueous extracts in the present study, but these possibilities of digestive disorders can be disregard in clinical use because they ate transient in the highest dosages male only.

• School Mathematics
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• v.15 no.3
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• pp.603-617
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• 2013

The major purpose of this article is to examine what kind of gap exists between mathematically gifted students' probability knowledge and the reality actually applying that knowledge and then analyze the cause of the gap. To attain the goal, 23 elementary mathematically gifted students at the highest level from G region were provided with problem situations internalizing a probability and expectation, and the problems are in series in which conditions change one by one. The study task is in a gaming situation where there can be the most reasonable answer mathematically, but the choice may differ by how much they consider a certain condition. To collect data, the students' individual worksheets are collected, and all the class procedures are recorded with a camcorder, and the researcher writes a class observation report. The biggest reason why the students do not make a decision solely based on their own mathematical knowledge is because of 'impracticality', one of the properties of probability, that in reality, all things are not realized according to the mathematical calculation and are impossible to be anticipated and also their own psychological disposition to 'avoid loss' about their entry fee paid. In order to provide desirable probability education, we should not be limited to having learners master probability knowledge included in the textbook by solving the problems based on algorithmic knowledge but provide them with plenty of experience to apply probabilistic inference with which they should make their own choice in diverse situations having context.

• Journal of Surface Science and Engineering
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• v.53 no.2
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• pp.59-66
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• 2020

Effects of Na₂SiO₃ concentration added into 0.1 M NaOH + 0.05 M NaF solution on the formation behavior and properties of PEO films on AZ91 Mg alloy were investigated under 1200 Hz of alternating current (AC) by voltage-time curves, in-situ observation of arc generation behavior and measurements of film thickness, surface roughness and micro vickers hardness. In the absence of Na₂SiO₃ in the 0.1 M NaOH + 0.05 M NaF solution, about 4 ㎛ thick PEO film was formed within 1 min and then PEO film did not grow but white spots were formed by local burning. Addition of Na₂SiO₃ up to 0.2 M caused more increased formation voltage and growth of PEO film with uniform generation of arcs. Addition of Na₂SiO₃ from 0.2 M to 0.4 M showed nearly the same voltage-time behavior and uniform arc generation. Addition of Na₂SiO₃ more than 0.5 M resulted in a decrease of formation voltage and non-uniform arc generation due to local burning. PEO film growth rate increased with increasing added Na₂SiO₃ concentration but maximum PEO film thickness was limited by local burning if added Na₂SiO₃ concentration is higher than 0.5 M. Surface roughness of PEO film increased with increasing added Na₂SiO₃ concentration and appeared to be proportional to the PEO film thickness. PEO film hardness increased with increasing added Na₂SiO₃ concentration and reached a steady-state value of about 930 H_V at more than 0.5 M of added Na₂SiO₃ concentration.

• Tuberculosis and Respiratory Diseases
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• v.73 no.2
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• pp.93-99
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• 2012

Background: Local adverse events associated with inhaled corticosteroid use, including dysphonia, pharyngitis and oral candidiasis, can affect adherence for treatment. 'Mouth rinsing method' has been used for reducing local adverse events, but it cannot ensure complete prevention. The goal of this pilot study was to identify whether the 'immediate diet method' can reduce local adverse events in a limited number of patients. Methods: The study was conducted in a total of 98 patients, who had been prescribed a medium-dose fluticasone propionate for the first time, from January to October in 2010. One training nurse had performed the education on how to use the inhaler, including the mouth rinsing method. And with follow-ups at one month intervals, any patient who experienced such adverse events were educated on the immediate diet method, having a meal within 5 minutes after using an inhaler and they were checked on any incurrence of adverse events with one month intervals for 2 months. Results: The mean age of patients was 65.9 years old. The local adverse events had incurred from 18.4% of the study subjects. When performed the follow-up observation in 18 patients with local adverse events after education on the immediate diet method, 14 patients (77.8%) had shown symptomatic improvements. Three of 4 patients did not show any improvement, in spite of implementing the immediate diet method. The other 1 patient did not practice the immediate diet method properly. Conclusion: The immediate diet method may be useful in reducing the local adverse events, caused by the use of inhaled corticosteroid.

• 보존과학연구
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• s.27
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• pp.5-22
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• 2006

Mireuksa is a temple that was established in the Baekjea Period and continued around to the 16thcentury. The sites of the temple throughout diverse periods such as the United Shilla Period, KoryuPeriod, and Chosun Period including the one of the early temple in the late Baekjea Period were discovered. In those temple sites, there were lots of diverse artifacts discovered including artifacts in the Bronze Age. In this study, the compositions of four bronze bells excavated from Mireuksa site in Iksan were analyzed and the manufacturing technique of bronze bells was studied through the observation of microstructure. Also, the analytical cases of ancient bronze bells were collected and compared. Furthermore, the provenance study of the bronze bells site was attempted with the Pbisotope ratio. The results aim to offer crucial keys for discovering the aspect of society as well as information about the origin, development, and the route of propagation of ancient technologies. Bronze bell No. 1 showed an unexpected composition as Cu was found 98.5% in it. There were shown twins which were created by annealing and an even phase in the fine grains. It was also shown that bronze bell No. 2 and 4 had a high content of Pb although they showed a similar composition with general bronze bells in terms of Sn content. As shown in the analysis characteristics table of Korean bronze bell of this study, the ancient bronze bell used Pb of which content was limited to 2.12% in general, however, the results showed 15.5% and 13.2% respectively, which is an excessive amount. Asa result of analyzing inclusion in the microstructure of bronze bell No. 2, it was found that sulfide group mineral was used since there appeared S(14.55%). Also, it was proven that $CuFeS_2$ or$Cu_5FeS_4$ was used as a raw material because there was a small amount of Fe. As a result of analyzing inclusion of bronze bell No. 4, the bronze bell sample contained S(13.43%) and it is thought that sulfide group mineral was used, however, it had no Fe. Therefore, it is not connected to $CuFeS_2$ which is the main mineral of Korea. In addition, a strain line was shown with processing in bronze bell No. 2 and 4. As a result of provenance study of bronze bell No. 2 and 4 using the Pb isotope ratio, they or their raw materials are estimated to come from the southern China. Bronze bell No. 3 showed only Cu and Sn, and it is featured with a relatively low amount of Sn(6.63%). The microstructure has only phase, andintergranular corrosion was highly in progress.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.624-630
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• 2012

The peer review learning is a method which improves learning outcome of students through feedback between students and the observation and analysis of other students. One of the important problems in a peer review system is to find proper evaluators to each learner considering characteristics of students for improving learning outcomes. Some of peer review systems randomly assign peer review evaluators to learners, or chose evaluators based on limited strategies. However, these systems have a problem that they do not consider various characteristics of learners and evaluators who participate in peer reviews. In this paper, we propose a novel prediction approach of learning outcomes to apply peer review systems considering various characteristics of learners and evaluators. The proposed approach extracts representative attributes from the profiles of students and predicts learning outcomes using various regression models. In order to verify how much outliers affect on the prediction of learning outcomes, we also apply several outlier removal methods to the regression models and compare the predictive performance of learning outcomes. The experiment result says that the SVR model which does not removes outliers shows an error rate of 0.47% on average and has the best predictive performance.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.65-77
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• 2016

Modeling for complex reacting flow in Fischer-Tropsch reactor is one of the challenges in the field of Computational Fluid Dynamics (CFD). It is hard to derive each and every reaction rate for all chemical species because Fisher-Tropsch reaction produces many kinds of hydrocarbons which include lots of isomers. To overcome this problem, after analyzing the existing methodologies for reaction rate modeling, non-Anderson-Schulz-Flory methodology is selected to model the detailed reaction rates. In addition, the inside flow has feature of multi-phase flow, and the methodologies for modeling multi-phase flow depend on the interference between the phases, distribution of the dispersed phase, flow pattern, etc. However, existing studies have used a variety of inside flow modeling methodologies with no basis or rationale for the feasibility. Modeling inside flow based on the experimental observation of the flow would be the best way, however, with limited resources we infer the probable regime of inside flow based on conventional fluid dynamics theory; select the appropriate methodology of Mixture model; and perform systematic CFD modeling. The model presented in this study is validated through comparisons between experimental data and simulation results for 10 experimental conditions.