• Communications of Mathematical Education
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• v.29 no.1
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• pp.51-72
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• 2015

This study aimed to analyze the characteristic of undergraduate students' perception and preference for mathematics. For this purpose, I surveyed 124 undergraduate students' metaphorical expressions about mathematics. I classified the expressions as four categories: a positive form, a negative form, a mixed form, an undecidable form. I investigated the proportion and characteristic of the metaphorical expressions according to the above four categories. Also, I surveyed the students' preference and nonpreference moments for mathematics and categorized them into 6-cases: elementary school, middle school, high school, university, always, and none. In addition, I examined the students' preference and nonpreference reasons for mathematics and classified them according to the 5-factors: grade factor, affective factor, content factor, teacher factor, and other factors. The results of this study as follows: First, the 27% of university students expressed their metaphorical expressions for mathematics as a positive form, 42% as a negative form, and 27% as a mixed form. Also, the preference rate for mathematics was higher as their school years increase and the main reasons of preference were grade and affective factors. The result of nonpreference rate was also higher as their school year increased. Students said that the contents and grade factor were the main factors among the 5-factors.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.441-449
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• 2010

The objective of this study was to investigate the physicochemical characteristics of soybeans cultivated in different regions and the accompanying soybean curd properties. To produce soybeans with regional competitiveness and demonstrate the distinctiveness of the soybean product, four regions(Paju, Andong, Muju, Hadong) and four varieties of soybean(Daewonkong, Daepungkong, Seonyukong, Cheogja 2) were selected for these experiments. There was a significant difference in the isoflavone content of soybeans and soybean curds(p<0.05). Soybeans from Andong had the highest content of genistein, daidzein and total isoflavone and soybeans from Hadong had the lowest content of these compound. Fatty acid composition of soybeans demonstrated a significant difference according to region(p<0.05). In particular, soybeans grown under adverse environmental conditions, such as high temperature and low latitude, contained the highest composition of oleic acid and the lowest composition of linoleic acid and linolenic acid. Although fatty acid content of soybean curd had a third of the fatty acid concentration of soybean, the same characteristic was observed in the fatty acid composition of soybean curd. In addition, both soybean and soybean curd had more than 80% unsaturated fatty acids and 50% of the unsaturated fatty acid content was linoleic acid. In conclusion, these results demonstrate the significant difference of soybean and soybean curd originating from different regions and showed the transition of nutritional constituents from soybean to soybean curd as a function of environmental factors. Therefore, we must consider these factors when manufacturing soy products.

• Industry Promotion Research
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• v.8 no.3
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• pp.181-199
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• 2023

E-commerce is gradually upgrading from traditional text and image formats to short video and livestreaming formats. Livestreaming e-commerce enriches the content and forms of information dissemination and product display, enhances the consumer's shopping experience, and gradually becomes the mainstream new consumer scene. However, there are many negative phenomena in the development of livestreaming e-commerce, such as false propaganda, counterfeit goods, and various negative events, which seriously affect the level of consumer trust in livestreaming e-commerce. Trust is the core competitive factor of livestreaming e-commerce. Based on previous research on trust theory and combined with the characteristic elements of "people, goods, and scenes" of livestreaming e-commerce, this article constructs a trust model for livestreaming e-commerce, proposes hypotheses, and proves through empirical research that factors such as store characteristics, livestream host characteristics, brand image, product information, platform reputation, livestreaming situation, and trust tendency have a significant positive impact on consumer trust. Based on the research conclusions, this article provides insights and management suggestions, such as emphasizing the construction of store characteristic indicators, creating desirable livestream host characteristics, focusing on product brand building and selection, maintaining the display of product information, selecting suitable livestreaming platforms, and creating rich content for livestreaming situations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.130-136
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• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.67-72
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• 2002

Water content of soils within pavement varies seasonally depending on climatic factors such as rainfall, temperature and so on, since a hydraulic gradient due to rainfall causes moisture flow, and a thermal gradient due to temperature change induces not only heat flow but also moisture flow directly and indirectly. Soils within pavement are usually in an unsaturated state, and heat flow and moisture flow have been recognized as coupled processes with complex interactions between them. This paper presents a one-dimensional analysis model by the finite element method for the coupled heat flow and moisture flow in unsaturated soils. The model can be used to predict not only the change of temperature and water content, but also frist heave with time. It will be a meaningful work for the design and maintenance of pavement to predict the change of the temperature and water content and frist heave. The model is tested through comparisons with the results by other models.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.732-750
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• 2019

Air drying was carried out on 15 Korean red pine logs to provide a prediction model of the moisture content (MC) change in the wood during drying. The final MC was 17.4% after 880 days since the beginning of air drying in the summer for 6 Korean red pine logs with 68.7% initial MC. The final MC was 16.0% after 760 days since the beginning of air drying in the winter for 9 Korean red pine logs with 35.8% initial MC. A regression model with R-squared of 0.925 was obtained as a result of multiple regression analyses with initial MC, top diameter, temperature, relative humidity, and wind speed as independent variable and and MC change during air drying as dependent variable. The initial MC and top diameter, which is the characteristic of Korean red pine, have greater effect on the MC decrease during air drying compared to meteorological factors such as the temperature, relative humidity, and wind speed. Two-dimensional mass transfer analysis was performed to predict the MC distribution of Korean red pine logs during air drying. Two prediction models with different air drying days and different meteorological factors for the determination of the diffusion coefficient and surface emission coefficient were presented. The error between the different two methods ranged from 0.1 to 0.8% and the difference from the measured value ranged from 2.2 to 3.6%. By measuring the internal MC during air drying of Korean pine logs with various initial MC and diameter, and calculating the moisture transfer coefficient in wood for each meteorological condition, the error of the prediction model can be reduced.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.248-261
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• 2018

This study, the Fear of Missing Out Scale (FoMO Scale) developed by Przybylski et al. (2013) was adapted and validated to the Korean culture. 3-factors were constructed through EFA and item content analysis. In the CFA, 3 models were constructed to verify the fit of the model. Compared the goodness of fit, 3-factors model with 8 items proved to be the most appropriate. Sub-factors extracted through the characteristic context and rationale of Korean culture are 'belonging needs', 'extrinsic motivation', and 'relative deprivation'. K-FoMO scale and the reliability level of each sub-factor were good. Convergent validity was assessed by significant correlation the K-FoMO scores with life satisfaction, positive emotions, negative emotions, and SNS addiction proneness. Discriminant validity was assessed by low correlation with gratitude. At the end, limitation and suggestions for the future research were discussed.

• Health Policy and Management
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• v.23 no.4
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• pp.415-426
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• 2013

Background: This study was aim to identify the specific words and to develop the scale for the public health center (PHC) image. Methods: We collected 824 words from the previous studies and by open questions and reduced them by 77 words, then which were rated properly by 355 citizens of Seoul. We examined explanatory factor analysis for 69 words, and examined content validity test and confirmatory factor analysis (CFA) for the image structures (4 factors and 16 words). And then we developed the image questionnaire using them through council. We conducted a survey and retested the PHC image scales as the measuring tool targeting 2,000 persons, and compared the inexperience and experience persons for PHC usage. Results: The image structures were consisted of 4 factors and 16 words such as 'trustworthiness' (warm, exemplary, faithful, service-mindedness, beneficial to health), 'fairness' (honesty, clear, consistent, ruled), 'development possibility' (changing, goal-directed, developmental, propulsive), and 'flexibility' (not authoritative, not perfunctory, not rigid) in total. Cronbach's ${\alpha}$ values of all factors were above 0.7. As a result of CFA, model fit indexes yielded satisfactory results (root mean square error of approximation [RMSEA] 0.049, goodness of fit index [GFI] 0.937, and adjusted goodness of fit index [AGFI] 0.912). According to the result of retest for measuring tool by using other samples, Cronbach's ${\alpha}$ values were above 0.8, and model fit indexes yielded satisfactory results (RMSEA 0.059, GFI 0.952, AGFI 0.933). RMSEAs of the inexperiences and the experiences were each 0.59, 0.68. Conclusion: A reliable, valid, and generalizable scale was created for PHC image.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.341-348
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• 2023

In this study, basic skin characteristic data was measured by measuring skin hydration, skin sebum secretion rate, skin melanin index, skin redness index, skin redness image analysis, transepidermal water loss (TEWL), and amount of stratum corneum before and after creating a temporary high temperature and low humidity environments targeting Korean women in their 20s to 50s. Stratum corneum by tape stripping was collected at each measurement and skin biomarkers including total protein content, carbonylated protein, neutral lipid, and lipid peroxidation were analyzed. Based on the results, the differences before and after creating a high temperature and low humidity environments were confirmed, the correlation between skin characteristics and skin biomarkers was confirmed, and a new skin index was created based on this. The new skin index can be used in product efficacy evaluation, and the possibility of constructing a new clinical study method and using skin biomarker discovery research through additional research was confirmed.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.5-12
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• 2019

The study is carried out to survey the proper management and to propose an eco - friendly separation system through efficient screening and resource recovery of excavated materials containing waste from various excavating fields such as reconstruction of landfill sites for reuse, reclamation of unsanitary landfill and residential land development of waste dumping sites. The current status and screening process and analytical characteristics of the excavated materials containing waste were reviewed. Through the analysis of the samples such as separated combustibles, recyclable soils and residues collected from the on-site visits we were able to understand the characteristics of separated materials and excavated materials containing waste such as calorific value, elementary composition, TOC, foreign material content and LOI. It has been found that elimination of the moisture of excavations, removal of attached soil from the surfaces of the excavated combustibles and the quantitative supply method of the input devices are the main operating factors as essential factors for the optimal separation of excavated materials containing waste. For efficient management and recycling of excavated materials containing, it is necessary to set criteria of ash content in separated combustibles and criteria organic matter content in separated soils.