• Journal of The Korean Association For Science Education
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• v.37 no.6
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• pp.921-935
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• 2017

The purpose of this research is to investigate trends of science educational researches on underrepresented students by scrutinizing Korean science education research literatures. For this particular purpose, literatures on underrepresented students were extracted from both listed and candidate journals for KCI and theses from 1984 to February 2017, and analyzed criteria such as source, year of publication, design, method, and content of research. A total of 125 papers from journals and 147 theses were extracted. In these researches, 61%, 20%, 6% were about students with disability, underachievers, and North Korean defector students respectively. The ratio of the researches on other underrepresented students such as multicultural, low income families, students who are from rural areas, and other underrepresented students were less than 5%. According to the year of publication, it was found that the number of research papers on underrepresented students increased continuously by a single digit from 1984 by focusing on the students with disability and underachievers. After that, from around 2008, it showed a rapid increase and researches on underrepresented students carried out more than 20 times annually. With regards to research design, there were 58% quantitative, 28% qualitative and 14% hybrid research design. Through analysis of research methods, we found that 30% of experimental research, 22% of interpretive research, 20% of correlation analysis, and 14% of survey research. After going through the characteristics of the research contents by visualizing the relationship between the research groups and the keywords that were extracted, it was found that even though the science education researches on underrepresented students have various contents, there were no keywords that were researched continuously and intensively in this area. The structural relationship between the keywords and each research group on underrepresented students showed that 'academic achievement' is the keyword with the highest degree of mediateness and connectedness.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.526-539
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• 2007

The purpose of this study is to investigate the influence of the Korean Wave on Chinese tourism to South Korea through a behavioral analysis of Chinese tourists in the general group package tours. China suppressed the needs of the Chinese people's geographical movement and imposed restrictions on information about the outside world with the use of a policy of "closure" for a long time. But since reforms and open-door policies were introduced in China, especially in the context of relaxation of control policies over Chinese outbound tourism after the mid-1990's, more and more Chinese make trips abroad including visits to South Korea. In this situation, the recent Korean Wave(especially, drama/film) describes the Korean national image by forming a bridge between fiction and reality and plays a pivotal role in broadening or reconstructing the geographical imagination of the Chinese people who have been historically isolated from the outside world. Although Chinese have imagined the Korean nationscape on the basis of geopolitical or economic factors in the past, they have currently broadened or reconstructed their geographical imagination to include socio-cultural factors related closely to the Korean way of life due to the recent Korean Wave. This newly constructed geographical imagination led by the Korean Wave functions as an important pulling factor in Chinese destination choices, affecting Chinese tourists' motivation formation and the recommendation of main attractions. The more influential the Korean Wave is on their destination choice, the more the respondents select the cultural factors in both their motivation for tourism to South Korea and their recommendations of tourism attractions to other people. Through the analysis results of both satisfaction and intention to revisit, the more influential the Korean Wave is on their destination choice, the higher is the degree of both satisfaction and intention to revisit. In other words, although Chinese tourism to South Korea is chiefly in the general group package tours, Chinese tourists who are influenced by Korean Wave on their destination choice have more attachment to(or affection for) Korea as a tourism destination. This result suggests that the Korean Wave affects qualitative change - that is, change of attitude - as well as quantitative change in Chinese demand for tourism to South Korea.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.446-452
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• 2005

In order to examine the natural distribution variations between groups of the Stewartia koreana, the leaf form characteristics of the investigation sites were analyzed by each group. As a result, the Mt. Kumsan group showed a smaller value in leaf length, width, area, and the number of veins, but not in the petiole length and serration number. Among each character, the coefficient of variation(CV) of the characters excluding petiole length and leaf area was in a comparatively narrow range, from 11.6~17.4%. On the other hand, the CV of petiole length and leaf area between the groups was 34.9% and 28.4% respectively. The CV of these characters within the group was also extraordinary- petiole length showed 29.5~42% and leaf area showed 27.7~40.7%. Also, the simple correlation analysis between 12 leaf characteristics showed that the correlation between leaf width and leaf area was high (r=0.975). The correlations between leaf length and leaf area, between leaf length and leaf width were 0.971 and 0.969, respectively. A negative correlation between angle of leaf base and ratio of leaf length to leaf width was discovered (r= -0.843), meaning that the ratio of leaf length to leaf width decreases as angle of leaf base increases. A cluster analysis was enforced among leaf characteristics of the selected group as a standard on the similarity of quantitative, qualitative measurements. The results showed that at a 0.4 distance level, the subjects could be classified into 4 groups. Group 1 was the Mt. Jogyesan and Mt. Kayasan group, group 2 was Mt. Paegunsan, group 3 was Mt. Unmunsan and Mt. Mudungsan, and group 4 was Mt. Kumsan. At a distance level of 0.6, the subjects were classified into two groups. Group 1 was the Mt. Ktimsan group and group 2 was Mt. Mudungsan, Unmunsan, Paegunsan, Kayasan, and Cogyesan. Especially the Mt. Kumsan group had the smallest value in the leaf characteristics of leaf length, width, area, and the number of veins, showing an obvious difference from the other five groups. There were five principal components that had a meaningful eigenvalue over 1.0 among the 12 extracted components. The explanatory power of the top two main components (leaf length and width) on the total variation was 52.7%. The explanatory power was 91.3% when all 5 main components were included.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.25-31
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• 2001

Oribatid mite communities in the process of litter decomposition were analyzed In Korean pine (Pinus koraiensis) forests of Namsan and Kwangreung, which were supposed to be under different environmental selective pressures. Oribatid mites were collected bimonthly from the litter bags (mesh size 0.4 mm, 1.7 mm) which was set up in the forest floor of study sites. This study had been carried out from Jan., 1997 to Sept., 1998. Species abundance of Kwangreung (mesh size 1.7 mm) was significantly higher than that of Namsan (mesh size 1.7 mm), but total no. of species did not exceed 30 species in all study sites. Concerning body length, medium sized oribatid mites (0.3-0.7mm) were more abundant than small ( < 0.3 mm) and large ( > 0.7 mm) sized mites. In Kwangreung, species whose body lengths were 0.2 mm to 0.5 mm were major group. However, a little larger species than Kwangreung's major group were dominant in Namsan. Sorenson similarity index and cluster analysis suggested that there were qualitative and quantitative differences in species composition in Namsan and Kwangreung. More species were collected in May through September than the other sampling times, but the pattern was rather different between first year and second year. Newly immigrant species were high in May in the first year and many of them regained on next year. Diversity indices suggested that species diversity of Kwangreung was higher than that of Namsan. Nearly 70% of total individual abundance was occupied by several dominant species in Namsan and Kwangreung . In the litter bags of mesh size 1.7 mm, the most dominant species was Trichogalumna nipponica in Namsan and Kwangreung, but in the litter bags of mesh size 0.4 mm in Kwangreung it was Ramusella sengbuschi which is smaller than T. nipponica. And important species related to litter decomposition were selected as follows; T. nipponica, Epidamaeus coreanus, Scheloribates latipes, Ceratozetes japonicus, Ramusella sengbuschi, Eohypochthonius crassisetiger, and Cultroribula lata.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.338-347
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• 1987

The research was carried out to investigate the related phenomena, the latent structures and synthetical characteristics in various growth factors of Phyllostachys bambusoides Sieb. et Zucc. growing at Damyang gun, Chollanamdo, using multivariate analysis. 1. By synthetical characteristics in canonical correlation between height-growth factor group and diameter-growth factor group, the former was determined by the culm height ($x_1$), and the latter by the. diameter of the largest internode($x_7$). And for those between quantitative growth factor group and qualitative growth factor group, the former was determined by the surface area($x_{10}$), and the latter by the diameter of the largest internode ($x_7$). 2. The ten growth factors of bamboo culm were simplified by two principal components on the basis of accumulated proportion aimed at 90%. The first principal component($Z_1$) as a "size factor" showed high correlation with growth factors except eye-height diameter($x_5$). The second principal component($Z_2$) as a "shape factor" showed high correlation only with $x_5$. 3. The bamboo culm, and the latent phenomenon between their growth factors could be determined by two common factors showing high communality(94.16%). The ten growth factors can be grouped into two attribute factors: quantity and quality. 4. The bamboo culms can be classified into five types: total, volume, shape-quality, inferior and middle.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.303-314
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• 2021

To understand how to efficiently observe the biomass and community of phytoplankton, phytoplankton sampling was carried out from June to October 2019 at the Yeongju dam sediment control reservoir(YJ) and Bohyeonsan dam reservoir(BH1 and BH2). The results derived from microscopic observation, such as the conventional phytoplankton qualitative/quantitative analysis, and from the CHEMTAX method based on the pigments, were compared. The relative contribution of phytoplankton, calculated by the microscopy and CHEMTAX methods, showed a significant difference in all four classes: cryptophyta, chlorophyta, cyanobacteria, and diatoms. In addition, the correlation between the two observation methods was poor. This might be caused by methodological differences in microscopy that do not consider the varying cell sizes among phytoplankton species. In this study, by converting the cells into carbon, the slope between both carbon biomasses based on microscopy and CHEMTAX was improved close to the 1 : 1 line, and the y-intercept was closer to 0 for cryptophyta and diatoms. For cyanobacteria, the slope increased, the y-intercept decreased, and the plot approached 1 : 1 although the correlation coefficients were not improved in all classes. The present study suggests that application of CHEMTAX based on pigment analysis could be a possible approach to efficiently determine the relative carbon proportions of individual classes of phytoplankton community composition.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.75-89
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• 2023

As the Mekong River basin is a nationally shared river, it is difficult to collect precipitation data, and the quantitative and qualitative quality of the data sets differs from country to country, which may increase the uncertainty of hydrological analysis results. Recently, with the development of remote sensing technology, it has become easier to obtain grid-based precipitation products(GPPs), and various hydrological analysis studies have been conducted in unmeasured or large watersheds using GPPs. In this study, rainfall-runoff simulation in the Mekong River basin was conducted using the SWAT model, which is a quasi-distribution model with three satellite GPPs (TRMM, GSMaP, PERSIANN-CDR) and two GPPs (APHRODITE, GPCC). Four water level stations, Luang Prabang, Pakse, Stung Treng, and Kratie, which are major outlets of the main Mekong River, were selected, and the parameters of the SWAT model were calibrated using APHRODITE as an observation value for the period from 2001 to 2011 and runoff simulations were verified for the period form 2012 to 2013. In addition, using the ConvAE, a convolutional neural network model, spatio-temporal correction of original satellite precipitation products was performed, and rainfall-runoff performances were compared before and after correction of satellite precipitation products. The original satellite precipitation products and GPCC showed a quantitatively under- or over-estimated or spatially very different pattern compared to APHPRODITE, whereas, in the case of satellite precipitation prodcuts corrected using ConvAE, spatial correlation was dramatically improved. In the case of runoff simulation, the runoff simulation results using the satellite precipitation products corrected by ConvAE for all the outlets have significantly improved accuracy than the runoff results using original satellite precipitation products. Therefore, the bias correction technique using the ConvAE technique presented in this study can be applied in various hydrological analysis for large watersheds where rain guage network is not dense.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.363-373
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• 2022

On April 29, 2021 (1st), June 2 (2nd), and August 17 (3rd), we surveyed benthic macroinvertebrates fauna at Muljangori-oreum wetland in Bonggae-dong, Jeju Island, Korea. Muljangori-oreum wetland was divided into four areas. The survey was conducted in three accessible areas (areas 1-3). As a result of habitat environment analysis, the average monthly temperature from 2017 to 2021 was the highest in July and August and the lowest in December and February. This pattern was repeated. As a result of analyzing changes in vegetation and water surface area through satellite images, normalized difference vegetation index (NDVI) increased from February to July and decreased after July. Normalized difference water index (NDWI) was analyzed to show an inverse relationship. A total of 21 species from 13 families were identified in the qualitative survey and a total of 412 individuals of 24 species from 15 families were identified in the quantitative survey. A total of 26 species from 17 families, 8 orders, 3 classes, and 2 phyla of benthic macroinvertebrates were identified. The dominant species was Chronomidae spp. with 132 individuals (32.04%). Noterus japonicus was a subdominant species with 71 individuals (17.23%). As a result of comparative analysis of species identified in this study and the literature, it was confirmed that species diversity was high for Coleoptera and Odonata. Main functional feeding groups (FFGs) were found to be predators. Habitat orientation groups (HOGs) were found to be swimmers. In OHC (Odonata, Hemiptera, and Coleoptera) group, 17 species (73.91%) in 2021, 23 species (79.31%) in 2016, 26 species (86.67%) in 2018, and 19 species (79.17%) in 2019 were identified. Cybister japonicus, an endangered species II, was confirmed to inhabit Muljangori-oreum wetland in the literature. Ten individuals (2.43%) were also confirmed to inhabit Muljangori-oreum wetland in 2021. Therefore, continuous management and habitat protection are required to maintain the habitat environment of C. japonicus in Muljangori-oreum wetland.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.57-70
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• 2023

The investigation delved into 457 pieces of scholarly work, encompassing articles, published theses, and dissertations from the National Research Foundation of Korea, spanning the period of the 1997 IMF financial crisis up to 2022. The materials were sourced using terms such as 'angel investment', 'angel investor', and 'angel investment attraction'. The initial phase involved filtering out redundant entries from the preliminary collection of 267 works, leaving aside pieces that didn't pertain directly to angel investment as indicated in their abstracts. The next stage of the analysis involved a more rigorous selection process. Out of 43 papers earmarked in the preceding cut, only 32 were chosen. The criteria for this focused on the exclusion of conference presentations, articles that were either not submitted or inconclusive, and those that duplicated content under different titles. The final selection of 32 papers underwent a thorough systematic literature review. These documents, all pertinent to angel investment in South Korea, were scrutinized under five distinct categories: 1) publication year, 2) themes of research, 3) strategies employed in the studies, 4) participants involved in the research, and 5) methods of research utilized. This meticulous process illuminated the existing landscape of angel investment studies within Korea. Moreover, this study pinpointed gaps in the current body of research, offering guidance on future scholarly directions and proposing social scientific theories to further enrich the field of angel investment studies and analysis also seeks to pinpoint which areas require additional exploration to energize the field of angel investment moving forward. Through a comprehensive review of literature, this research intends to validate the establishment of future research trajectories and pinpoint areas that are currently and relatively underexplored in Korea's angel investment research stream. This study revealed that current research on domestic angel investment is concentrated on several areas: 1) the traits of angel investors, 2) the motivations behind angel investing, 3) startup ventures, 4) relevant institutions and policies, and 5) the various forms of angel investments. It was determined that there is a need to broaden the scope of research to aid in enhancing and stimulating the scale of domestic angel investing. This includes research into performance analysis of angel investments and detailed case studies in the field. Furthermore, the study emphasizes the importance of diversifying research efforts. Instead of solely focusing on specific factors like investment types, startups, accelerators, venture capital, and regulatory frameworks, there is a call for research that explores a variety of associated variables. These include aspects related to crowdfunding and return on investment in the context of angel investing, ensuring a more holistic approach to research in this domain. Specifically, there's a clear need for more detailed studies focusing on the relationships with variables that serve as dependent variables influencing the outcomes of angel investments. Moreover, it's essential to invigorate both qualitative and quantitative research that delves into the theoretical framework from multiple perspectives. This involves analyzing the structure of variables that have an impact on angel investments and the decisions surrounding these investments, thereby enriching the theoretical foundation of this field. Finally, we presented the direction of development for future research by confirming that the effect on the completeness of the business plan is high or low depending on the satisfaction of the entrepreneurs in addition to the components.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.55-66
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• 2018

Purpose In PET/CT exam, washed-out artifact could occur due to severe motion of the patient and high specific activity, it results in lowering not only qualitative reading but also quantitative analysis. Scatter limitation correction by GE is an algorism to correct washed-out artifact and recover the images in PET scan. The purpose of this study is to measure the threshold of specific activity which can recovers to original uptake values on the image shown with washed-out artifact from phantom experiment and to compare the quantitative analysis of the clinical patient's data before and after correction. Materials and Methods PET and CT images were acquired in having no misalignment(D0) and in 1, 2, 3, 4 cm distance of misalignment(D1, D2, D3, D4) respectively, with 20 steps of each specific activity from 20 to 20,000 kBq/ml on $^{68}Ge$ cylinder phantom. Also, we measured the distance of misalignment of foley catheter line between CT and PET images, the specific activity which makes washed-out artifact, $SUV_{mean}$ of muscle in artifact slice and $SUV_{max}$ of lesion in artifact slice and $SUV_{max}$ of the other lesion out of artifact slice before and after correction respectively from 34 patients who underwent $^{18}F-FDG$ Fusion Whole Body PET/CT exam. SPSS 21 was used to analyze the difference in the SUV between before and after scatter limitation correction by paired t-test. Results In phantom experiment, $SUV_{mean}$ of $^{68}Ge$ cylinder decreased as specific activity of $^{18}F$ increased. $SUV_{mean}$ more and more decreased as the distance of misalignment between CT and PET more increased. On the other hand, the effect of correction increased as the distance more increased. From phantom experiments, there was no washed-out artifact below 50 kBq/ml and $SUV_{mean}$ was same from origin. On D0 and D1, $SUV_{mean}$ recovered to origin(0.95) below 120 kBq/ml when applying scatter limitation correction. On D2 and D3, $SUV_{mean}$ recovered to origin below 100 kBq/ml. On D4, $SUV_{mean}$ recovered to origin below 80 kBq/ml. From 34 clinical patient's data, the average distance of misalignment was 2.02 cm and the average specific activity which makes washed-out artifact was 490.15 kBq/ml. The average $SUV_{mean}$ of muscles and the average $SUV_{max}$ of lesions in artifact slice before and after the correction show a significant difference according to a paired t-test respectively(t=-13.805, p=0.000)(t=-2.851, p=0.012), but the average $SUV_{max}$ of lesions out of artifact slice show a no significant difference (t=-1.173, p=0.250). Conclusion Scatter limitation correction algorism by GE PET/CT scanner helps to correct washed-out artifact from motion of a patient or high specific activity and to recover the PET images. When we read the image occurred with washed-out artifact by measuring the distance of misalignment between CT and PET image, specific activity after applying scatter limitation algorism, we can analyze the images more accurately without repeating scan.