• Journal of Korean Elementary Science Education
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• v.41 no.1
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• pp.106-117
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• 2022

This study analyzes the characteristics of the "Conclusions" section of a thesis in elementary science education and presents a conclusion model that can be used in elementary science education. In the "Elementary Science Education" journal published by the Elementary Science Education Association, the conclusion section was analyzed on the four-year academic papers published. First, the title of the concluding chapter and the number of conclusions frequently used in elementary science education were identified. Results showed that most commonly used title for the conclusion section was "Conclusion and Suggestion," and the length of the section was 85.4 lines or 2.1 pages.. Then, as a result of analyzing the conclusions of elementary science journals in sentence units, we found stages as a kind of semantic unit frequently used in elementary science education papers. Further, we obtained that these stages are often used in connection with specific stages. Finally, a conclusion template for papers commonly used in elementary science education was presented. The results of this study can be used as basic data when drafting elementary science education papers. Furthermore, specific thesis regarding education plans and educational materials might be prepared for elementary science education graduate students based on the present results.

• Journal of Mushroom
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• v.20 no.4
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• pp.274-278
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• 2022

The present study aimed at selecting a cost-effective substrate for king oyster mushroom based on the growth characteristics of fruiting body for use as a basic resource to ensure stable production on farms. Compositional analysis of substrates manufactured with different materials in each process revealed that the total carbon content was 42.24-48.22% higher and the total nitrogen content was 1.7-2.29% higher in the processed lot than in the control (i.e., substrate used by the farmhouse; 40.86% and 1.39%, respectively). Meanwhile, the carbon-to-nitrogen ratio was the highest in the control (27.9% vs. 19.12-27.88% in the processed lot). When cultured for 28 days, the mycelium growth was 11.5 and 11.3 mm in substrates 1 and 6, respectively, indicating the fastest growth; meanwhile, the values were 10.1-10.3 mm in the control and substrate 11, showing a similar tendency. Mycelial density did not differ significantly among the processed lots. Yield per bottle was higher in substrates 8 (205.95 g/bottle), 7 (178.51 g/bottle), and 11 (170.63 g/bottle) than in the control (152.2 g/bottle). Fruiting body quality was comparable to controls in all processed lots. Overall, economic effects, such as substrate material prices, should be analyzed, and stability evaluations, such as residual pesticide and harmful microorganisms, should be undertaken along with further detailed examination to ensure safe and stable production on farms.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.80-85
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• 2023

New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.

• Journal of Korean Library and Information Science Society
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• v.53 no.2
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• pp.73-94
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• 2022

This study is a basic research for establishing a mid- to long-term development plan for the library of the Korea Expressway Corporation that can establish the vision and core values of the library and continuously grow by taking advantage of the specialization of the road transportation field in preparation for the 4th industrial revolution and post-corona era. The current state, satisfaction, and demand of the library were conducted for users of the Korea Expressway Corporation, and based on this, a mid- to long-term development plan was proposed. As a result of the research, first, the library of the Korea Expressway Corporation should provide information services to respond to the immediate information needs of its members as a library that supports academic and research activities as well as the comprehensive collection and preservation of related materials as a national road transportation representative library. Second, it is necessary to establish a systematic collection development policy, and it is necessary to collect collections by detailed themes related to road traffic. Third, overall service development is necessary, and Korea Expressway Corporation library homepage and mobile service should be developed. Lastly, space improvement must be made through space reorganization, and it is necessary to expand the usability through the introduction of the latest technology.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.120-128
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• 2022

Printed circuit boards (PCBs) are a basic component in the electronics industry and are widely used in nearly all electronic products, such as mobile phones, tablet computers, and digital cameras, as well as in electric equipment. PCB manufacturing involves the use of many chemicals and chemical processes and therefore has more risks than other manufacturing sectors. This study aims to identify the causes of possible accidents during PCB manufacturing through risk assessment, develop and implement safety measures, and evaluate the effectiveness of these measures. Note that the safety measures developed to mitigate the risks of a certain process were also implemented for other similar processes. The risk assessments conducted over seven years, from 2015 to 2021, at a PCB manufacturing company identified 361 hazardous processes. Between 2016 and 2019, 41-56 hazardous processes were identified per year; such processes decreased to fewer than 20 per year after 2020. Application of the risk assessment results to the improvement of the hazardous processes with the similar characteristics seems to be effective in decreasing the risks. Equipment-related factors such as lack of appropriate maintenance, low work standards, and defective protection devices were responsible for 59.8% of all possible accidents. Because PCB manufacturing involves many chemicals, skin contact with hazardous substances, electric shock, fire, and explosion were the most common types of possible accidents (81.7%). In total, 505 safety measures were implemented, including 157 related to purchase and improvement of equipment and devices for safety (31.1%), 147 related to the installation/modification of fire prevention facilities (29.1%), and 69 related to the use of standard electrical appliances (13.7%). Risk assessment conducted after implementing the safety measures showed that these measures significantly decreased risk; 247 processes (68.4%) had a risk level of 3, corresponding to "very low," and 114 processes (31.6%) showed a risk level of 4, corresponding to "low." In particular, risk assessment of 104 processes with risk scores of 12 and 10 other processes with risk score of 16 showed that the risk decreased to 4 after implementing the safety measures. Thus, implementing these measures in similar manufacturing sectors that involve chemical processes can mitigate risk.

• Journal of Mushroom
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• v.19 no.4
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• pp.294-299
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• 2021

The purpose of this study is to provide basic data on the safety of Poria cocos, a major Korean herbal medicine, and to establish tolerance levels for hazardous substances. Residual pesticides (321 types), heavy metals (7 types), radioactivity (3 types), and ash content were analyzed in 10 Poria cocos products distributed in Korea (5 domestic and 5 in China). Of the residual pesticides, cypermethrin was detected at 0.03 mg/kg in one domestic sample and was below the standard value. Of the heavy metals, the levels of Zn, Pb, Ni, Cu, Hg, and Cr were below the standard values in all samples. Hg was not detected in any sample. Cd was detected at 0.011 mg/kg in one Chinese sample. The radioactivity concentration was also below the MDA value in all P. cocos samples. The ash content was less than the standard value of 1.0% in all P. cocos samples. The findings indicate that P. cocos distributed in Korea is safe. However, because P. cocos is always exposed to harmful substances because of the nature of its cultivation in the soil, it seems necessary to establish systematic management standards for the entire production stage, such as cultivation, storage, and distribution.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.267-278
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• 2021

This study differentiated it from previous studies by selecting Chinese lifestyle shops in the current situation where lifestyle shops are rapidly emerging due to the increase in single-person households in China and changes in consumption patterns. The purpose of this study is to present basic data for establishing VMD strategies for domestic lifestyle shops wishing to enter China through the analysis of the characteristics of VMD elements. The results of this study are as follows.The research results are as follows. In the display elements of the VMD of Chinese lifestyle shops-GAROSU, CH'IN, and Nome, the appliances and props used differentiated shapes and materials according to the product concept and design. There seemed to be a difference depending on the concept of the lifestyle shop. Also, there were differences in the form of VP and the presentation method of PP and IP in VP, PP, and IP according to the store product group and the amount of products displayed in the presentation element. In a follow-up study, it is considered meaningful to conduct a study on domestic lifestyle shops and a comparative analysis of VMD between Chinese and domestic lifestyle shops.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.330-343
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• 2022

BACKGROUND/OBJECTIVES: Zanthoxylum schinifolium is traditionally used as a spice for cooking in East Asian countries. This study was undertaken to evaluate the anti-proliferative potential of ethanol extracts of Z. schinifolium leaves (EEZS) against human bladder cancer T24 cells. MATERIALS/METHODS: Subsequent to measuring the cytotoxicity of EEZS, the anti-cancer activity was measured by assessing apoptosis induction, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP). In addition, we determined the underlying mechanism of EEZS-induced apoptosis through various assays, including Western blot analysis. RESULTS: EEZS treatment concentration-dependently inhibited T24 cell survival, which is associated with apoptosis induction. Exposure to EEZS induced the expression of Fas and Fas-ligand, activated caspases, and subsequently resulted to cleavage of poly (ADP-ribose) polymerase. EEZS also enhanced the expression of cytochrome c in the cytoplasm by suppressing MMP, following increase in the ratio of Bax:Bcl-2 expression and truncation of Bid. However, EEZS-mediated growth inhibition and apoptosis were significantly diminished by a pan-caspase inhibitor. Moreover, EEZS inhibited activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway, and the apoptosis-inducing potential of EEZS was promoted in the presence of PI3K/Akt inhibitor. In addition, EEZS enhanced the production of ROS, whereas N-acetyl cysteine (NAC), a ROS scavenger, markedly suppressed growth inhibition and inactivation of the PI3K/Akt signaling pathway induced by EEZS. Furthermore, NAC significantly attenuated the EEZS-induced apoptosis and reduction of cell viability. CONCLUSIONS: Taken together, our results indicate that exposure to EEZS exhibits anti-cancer activity in T24 bladder cancer cells through ROS-dependent induction of apoptosis and inactivation of the PI3K/Akt signaling pathway.

• Journal of Korean Elementary Science Education
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• v.41 no.1
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• pp.150-161
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• 2022

Matter is a basic concept that students should understand during their science classes. However, many difficulties are associated with understanding the concepts of matter due to its abstraction. In this study, the elementary school students' understanding of the concept of matter and the examples of matter and non-matter are investigated and analyzed by grade. The subjects of this study were 418 students from third grade to sixth grade. The survey was conducted using a free-response questionnaire comprising three questions. The results are as follows. First, the elementary school students' conceptions of matter were "materials that make up objects," "what can be seen and touched," and "solid, liquid, and gas." As the grade increased, the explanations for a material decreased and the explanations for the state of matter increased. Furthermore, only few students explained matter in terms of mass and volume. Second, solids were the most common examples of matter presented by the students, and liquids and gases were included in the upper grades. However, there were many cases in the upper grades where students were unable to distinguish between objects and matter. Third, non-matter was properly presented by the 6th graders as compared to the other graders, and in many cases, objects, liquids, and gases were mentioned as non-matter. Fourth, it was found that the students' conceptions of matter influenced the examples of matter and non-matter that they presented.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.302-311
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• 2022

Sound barrier walls are one of the most effective alternatives for reducing environmental noise on roads and railways in the city center. The insertion loss of the sound barrier against road traffic noise is the sum of the sound transmission loss, sound absorption loss, and sound energy reduction due to the diffraction attenuation of the sound barrier. The sound transmission loss of the sound barrier is one of the important factors that determine the insertion loss of the sound barrier and is a basic indicator that determines the performance of the sound barrier. Nevertheless, there is not a separate standard in Korea for measuring the acoustic transmission loss of sound barrier panels. There are only a few conditions in KS F 4770 series that stipulates on the general material of sound barrier panels. This thesis examines the necessity of the acoustic transmission loss measurement and evaluation standards of sound barrier walls, and seeks a measurement method in a free sound field (anechoic chamber) sound receiving room considering the characteristics of sound barrier walls installed in external spaces, unlike indoor building materials. In addition, a single number evaluation method using a reference spectrum was proposed so that the sound insulation effect according to various installation places such as roadside or railroad side can be easily displayed.