• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.61-61
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• 2020

본 연구는 우리나라 임상 중에서 침엽수림과 침활혼효림으로 구성된 산양삼 시험포지를 선정하고, 임상별 토양의 토양세균군집을 분석하여 산양삼 생육특성과의 상관관계 구명하고자 수행하였다. 산양삼 시험포지는 침염수림으로 구성된 충주 산양삼 종자공급단지와 침활혼효림으로 구성된 함양 산양삼 종자공급단지를 선정하여 각각 조성하였다. 토양세균군집 분석은 pyrosequencing analysis (Illumina platform)를 이용하였고, 토양세균군집과 생육특성 간의 상관관계는 Pearson's correlation을 이용하여 분석하였다. 임상별 시험포지의 토양세균은 두 시험포지 모두 Acidobacteria가 우점종으로 확인되었다. 주좌표 분석을 통해 임상별 산양삼 시험포지에서 우점하는 토양세균 군집을 확인한 결과, 먼저 토양세균 군집은 임상별 시험포지에 따라 군집화를 이루는 것으로 확인되었고, Pearson's 상관관계 분석 결과, 토양세균 군집의 상대적 빈도수는 수종 비율에 따라 상이한 상관관계를 보이는 것으로 확인되었다. 이 중에서 Proteobacteria, Alphaproteobacteria, Actinobacteria_class, Phycisphaerae는 침엽수의 비율과 유의적인 정의 상관관계를 보였고, Nitrospirae, Chlamydiae, Planctomycetia, Acidobacteria_6는 활엽수의 비율과 유의적인 정의 상관관계를 보이는 것으로 나타났다. 또한 임상별 산양삼 시험포지의 토양세균 군집과 산양삼 생육특성 간의 상관관계를 분석한 결과, Nitrospirae, Chlorobi, Planctomycetia, Acidobacteria_6가 산양삼의 생육과 유의적인 정의 상관관계를 보였다. 본 연구결과를 바탕으로 다양한 산림환경에서 토양세균군집과 산양삼 생육특성 간의 상관관계를 명확하게 구명할 수 있다면 향후 산양삼의 최적 재배지를 선정하는데 있어 도움을 줄 수 있을 것으로 사료된다.

• Education of Primary School Mathematics
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• v.26 no.4
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• pp.349-368
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• 2023

The purpose of this study is to explore ways for students to connect conceptual and procedural knowledge in mathematical modeling lessons. Accordingly, we selected the greatest common divisor among the learning contents in which elementary school students have difficulties connecting conceptual and procedural knowledge. A mathematical modeling lesson was designed and implemented to solve problems related to the greatest common divisor while connecting conceptual and procedural knowledge. As a result of the analysis, it was found that the mathematical modeling lesson had positive effects on students solving problems by connecting conceptual and procedural knowledge. In addition, through actual class application, a teaching and learning plan was derived to meaningfully connect conceptual and procedural knowledge in mathematical modeling lessons.

• Education of Primary School Mathematics
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• v.27 no.2
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• pp.155-171
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• 2024

This study compared and analyzed students' reasoning processes and justification methods when introducing the concept of "the sum of angles in a triangle" in mathematics classes with a focus on both measurement and geometric aspects. To confirm this, the research was conducted in a 4th-grade class at H Elementary School in Suwon, Gyeonggi-do, South Korea. The conclusions drawn from this study are as follows. First, there is a significant difference when introducing "the sum of angles in a triangle" in mathematics classes from a measurement perspective compared to a geometric perspective. Second, justifying the statement "the sum of angles in a triangle is 180°" is more effective when explained through a measurement approach, such as "adding the sizes of the three angles gives 180°," rather than a geometric approach, such as "the sum of the angles forms a straight angle." Since elementary students understand mathematical knowledge through manipulative activities, the level of activity is connected to the quality of mathematics learning. Research on this reasoning process will serve as foundational material for approaching the concept of "the sum of angles in a triangle" within the "Geometry and Measurement" domain of the Revised 2022 curriculum.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.873-884
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• 2024

Flunixin is a veterinary nonsteroidal anti-inflammatory agent whose residues have been investigated in their original form within tissues such as muscle and liver. However, flunixin remains in milk as a metabolite, and 5-hydroxy flunixin has been used as the primary marker for its surveillance. This study aimed to develop a quantitative method for detecting flunixin and 5-hydroxy flunixin in milk and to strengthen the monitoring system by applying to other livestock and fishery products. Two different methods were compared, and the target compounds were extracted from milk using an organic solvent, purified with C₁₈, concentrated, and reconstituted using a methanol-based solvent. Following filtering, the final sample was analyzed using liquid chromatography-tandem mass spectrometry. Method 1 is environmentally friendly due to the low use of reagents and is based on a multi-residue, multi-class analysis method approved by the Ministry of Food and Drug Safety. The accuracy and precision of both methods were 84.6%-115% and 0.7%-9.3%, respectively. Owing to the low matrix effect in milk and its convenience, Method 1 was evaluated for other matrices (beef, chicken, egg, flatfish, and shrimp) and its recovery and coefficient of variation are sufficient according to the Codex criteria (CAC/GL 71-2009). The limits of detection and quantification were 2-8 and 5-27 ㎍/kg for flunixin and 2-10 and 6-33 ㎍/kg for 5-hydroxy flunixin, respectively. This study can be used as a monitoring method for a positive list system that regulates veterinary drug residues for all livestock and fisheries products.

• Education of Primary School Mathematics
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• v.27 no.1
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• pp.19-38
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• 2024

This study aims to analyze the characteristics of students' understanding of artificial intelligence and mathematical concepts by developing and applying an artificial intelligence education program for mathematics convergence using robots. To this end, we analyzed the content standards of elementary artificial intelligence education to extract conceptual elements of artificial intelligence and identified mathematics achievement standards that can effectively integrate them. In particular, a five-session (15 classes in total) program was developed by selecting the units 'angle' and 'quadrilateral' suitable for utilizing the robot's movement and reorganizing the lesson to integrate the mathematics achievement standard with the artificial intelligence content elements. As a result of applying this to 22 fourth grade elementary school students over five months and analyzing the students' understanding revealed by topic of artificial intelligence content, the artificial intelligence education program for mathematics convergence using robots was helpful in students' understanding artificial intelligence principles and mathematical concepts. In addition, the use of robots was confirmed to improve students' understanding of artificial intelligence and mathematics as well as their participation in class by making them visually check a series of performing procedures.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.125-135
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• 1994

Field experiment was carried out in order to clarify effects of plastic film mulching on temperature and moisture of rhizosphere soil and their subsequent effects on seedling emergence, earlier growth, vegetative growth and grain yield of sesame. The textural class of the experimental field soil was the sandy loam(Bonyang series) and the variety of sesame planted was "Ansan-ggae". The experiment was conducted by combining four sowing dates of April 25, May 10, May 25, June 10 and two mulching treatments(mulching, non-mulching) over two year of 1991 and 1992. The results were summarized as follows : 1. The daily mean soil temperature of 5cm deep soil was increased by 1.4 to $2.8^{\circ}C$ by plastic film mulching. The average soil water content was increased by 0.5 to 3.0%(V/V) in the drier season, while decreased by 1.0 to 2.0%(V/V) in the rainy season by mulching. 2. The establishment rate of sesame seedling was very sensitive to soil temperature. For normal seedling emergence, from the seeding date to the 7th date after sowing, the daily mean soil temperature higher than $21.0^{\circ}C$ was required at the experimental field conditions. 3. The average soil water content in the range of 14.0 to 21.0%(V/V) at 5cm deep soil seemed not to be limiting for the germination and emergence of sesame. The effect of soil water content on seedling establishment was very small in this range, but the optimum level of soil water content ranged from 14.0 to 15.0%(V/V) in the experimented sandy loam. 4. The wetter the soil profile was, the larger the gap of soil temperature between the mulched and non-mulched condition was. The effect of mulching on the establishment rate of sesame seedlings was much greater in the lower air temperature conditions. However, when the sowing of sesame came earlier than at the date with the daily mean air temperature below $19.0^{\circ}C$, the effects of earlier sowing and mulching were offsetted by the retarded seedling growth due to the low air temperature, and thus earlier sowing with mulching did not enhance the grain yield of sesame.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.54-61
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• 2000

Amalgam, though a widely used dental material, does not bond to the tooth substrate Therefore, retentive preparation of the cavity is necessary. Such amalgam restorations, until corrosion products form and plug the margin, will show significant marginal leakage. Unless this is prevented early on, saliva and bacteria may enter the cavity causing postoperative hypersensitivity, dissolution and collapse of the restoration, discoloration of the margin and secondary caries, leading to shortened life-span of the restoration and pulpal pathosis. Recently, a method of restoration has been introduced whereby tooth material can be preserved, cavity margin can be sealed and preventive treatment of pit and fissure can be administered while retaining all the advantages of conventional amalgam restorations. Such sealed amalgams involve removing the carious lesion without extending the cavity for prevention and using pit and fissure sealants to seal cavity margins and pit and fissures to reduce microleakage. In this study, finishing of the amalgam and sealant application were performed after different intervals following of amalgam restoration to compare the microleakage of sealed and conventional amalgam restorations. Thirty bicuspids were prepared with Class V cavity preparations on the buccal and lingual surfaces. After amalgam placement, they were divided into the following groups and treated accordingly. Group 1 : Polishing after 24 hours Group 2 : Immediate sealant application without polishing Group 3 : No polishing, but sealant applied after thermocycling 500 times After treatment, the samples were thermocycled 500 times between $5^{\circ}C$ and $55^{\circ}C$ with a dwell time of 30 seconds. After thermocycling, the samples were dipped into 1% methylene blue kept in a $37^{\circ}C$ incubator at 100% humidity for 24 hours. The teeth were then embedded in resin and cut bucco-lingually along the tooth axis and observed with a stereomicroscope to determine the degree of microleakage, The following results were obtained : 1. Group 2 showed the least microleakeage, while group 1 showed the greatest. 2. Group 1 showed significantly greater microleakage compared to group 2 (p<0.05). However, no significant differences were found between group 1 and 3(p>0.05). No significant differences in microleakage were also found between cup 2 and 3(p<0.05).

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.228-232
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• 2016

As the quantity of HNS sea trasport and the number of HNS accidents at sea are increasing recently, the importance of HNS management is emphasized so that we try to develop marine accident case standard code for making HNS accidents at sea databased systemically in this study. First and foremost, we draw the related requisites of essential accident reports along with internal and external decrees and established statistics of classified items for conducting study, and we referred to analogous standard codes obtained from developed countries in order to research code design. Code design is set like 'Accident occurrence ${\rightarrow}$ The initial accident information ${\rightarrow}$ Accident response ${\rightarrow}$ Accident investigation' in accordance with the general flow of marine HNS accidents of in which the accident information is input and queried. We classified initial accident information into the items of five categories and constructed "Preliminary Information Code(P.I.C.)". In addition we constructed accident response in two categories and accident investigation in three categories that get possible after the accident occurrence as called "Full Information(F.I.C.)", including the P.I.C. It is represented in 3 kinds of steps on each topic by departmentalizing the classified majority as classified middle class and classified minority. As a result of coding marine HNS accident and of the code to a typical example of marine HNS accident, HNS accident was ascertained to be represented sufficiently well. We expect that it is feasible to predict possible trouble or accident henceforward by applying code, and also consider that it is valuable to the preparedness, response and restoration in relation to HNS accidents at sea by managing systemically the data of marine HNS accidents which will occur in the future.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.230-251
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• 2017

According to the survey on higher fungi from 2009 to 2011 and also in 2015 in Byeonsanbando National Park, a total of 2 division, 6 class, 18 orders, 61 families, 157 genera and 323 species were observed. In case of Agaricales, there were 23 families, 67 genera and 153 species; Boletales, there were 6 families, 27 genera and 45 species; Russulales, there were 3 family, 4 genera and 40 species; Polyporales, there were 6 family, 21 genera, 28 species. Thus, most of them belonged to the following 4 orders: Agaricales, Russulales, Boletales and Polyporales. Dominant species belonged to Boletaceae (37 species), Russulaceae (36 species), Agaricaceae (28 species) and Amamtaceae (25 species). For the habitat environment, the ectomycorrhizal mushrooms were 40.2% (poisonous mushrooms, 46 species; edible & medicinal mushrooms, 51 species; unknown edible & poisonous mushrooms, 26 species), litter decomposing and wood rotting fungi 35.3%(poisonous mushrooms, 10 species; edible & medicinal mushrooms, 52 species; unknown edible & poisonous mushrooms, 46species), grounding Fungi 22.3%(poisonous mushrooms, 8 species; edible & medicinal mushrooms, 31 species; unknown edible & poisonous mushrooms, 29 species). Monthly, most of poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms were found in July and August. In terms of altitude, the most species were observed at 1~99m and the populations dropped by a significant level at an altitude of 200m or higher. It seemed that the most diversified poisonous mushrooms, edible & medicinal mushrooms and unknown edible & poisonous mushrooms occurred at climate conditions with a mean air temperature at $24.0{\sim}25.9^{\circ}C$, the highest air temperature at $28.0{\sim}29.9^{\circ}C$, the lowest air temperature at $20.0{\sim}21.9^{\circ}C$, a relative humidity at 77.0~79.9% and a rainfall of 300.0~499.9mm.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.248-259
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• 2007

The aim of this research was to study the effect of intermittent polymerization on marginal adaptation by comparing the marginal adaptation of intermittently polymerized composite to that of continuously polymerized composite. The materials used for this study were Pyramid (Bisco Inc., Schaumburg, U.S.A.) and Heliomolar (Ivoclar Vivadent, Liechtenstein) . The experiment was carried out in class II MOD cavities prepared in 48 extracted human maxillary premolars. The samples were divided into 4 groups by light curing method: group 1- continuous curing (60s light on with no light off), group 2-intermittent curing (cycles of 3s with 2s light on & 1s light off for 90s); group 3- intermittent curing (cycles of 2s with 1s light on & 1s light off for 120s); group 4- intermittent curing (cycles of 3s with 1s light on & 2s light off for 180s). Consequently the total amount of light energy radiated was same in all the groups. Each specimen went through thermo-mechanical loading (TML) which consisted of mechanical loading (720,000 cycles, 5.0 kg) with a speed of 120 rpm for 100hours and thermocycling (6000 thermocycles of alternating water of $50^{\circ}C$ and $55^{\circ}C$). The continuous margin (CM) (%) of the total margin and regional margins, occlusal enamel (OE), vertical enamel (VE), and cervical enamel (CE) was measured before and after TML under a $\times200$ digital light microscope. Three-way ANOVA and Duncan's Multiple Range Test was performed at 95% level of confidence to test the effect of 3 variables on CM (%) of the total margin: light curing conditions, composite materials and effect of TML. In each group, One-way ANOVA and Duncan's Multiple Range Test was additionally performed to compare CM (%) of regions (OE, VE CE). The results indicated that all the three variables were statistically significant (p < 0.05). Before TML, in groups using Pyramid, groups 3 and 4 showed higher CM (%) than groups 1 and 2, and in groups using Heliomolar. groups 3 and 4 showed higher CM (%) than group 1 (p < 0.05). After TML, in both Pyramid and Heliomo)ar groups, group 3 showed higher CM (%) than group 1 (p < 0.05) CM (%) of the regions are significantly different in each group (p < 0.05). Before TML, no statistical difference was found between groups within the VE and CE region. In the OE region, group 4 of Pyramid showed higher CM (%) than group 2, and groups 2 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). After TML, no statistical difference was found among groups within the VE and CE region. In the OE region, group 3 of Pyramid showed higher CM (%) than groups 1 and 2, and groups 2,3 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). It was concluded that intermittent polymerization may be effective in reducing marginal gap formation.