• Korean Journal of Ecology and Environment
• /
• v.53 no.1
• /
• pp.11-21
• /
• 2020

In this study, we compared the spatio-temporal differences of phytoplankton communities among 4 lakes in the Boseong River basin. Field research was conducted quarterly from 2014 to 2017 for this study. A total of 345 species of phytoplankton were identified including 107 Bacillariophyceae, 175 Chlorophyceae, 27 Cyanophyceae and 36 other phytoplankton taxa. Lake Boseong showed higher species numbers and density of phytoplankton than other lakes (Dunn's test, P<0.01). Bacillariophyceae such as Asterionella formosa, Aulacoseira granulata, Fragilaria crotonensis was dominated in most research periods, whereas Scenedesmus ecornis and Coelastrum cambricum belonging to Chlorophyceae were dominant species on August. The self-organizing map (SOM) classified 3 clusters with 10 × 7 grid and showed spatio-temporal variation of phytoplankton communities based on significant difference among each clusters. Total 31 species of phytoplankton were chosen as a indicator species using indicator species analysis(ISA) and reflected seasonal phytoplankton succession and diversity and density of phytoplankton according to nutrient concentration. Water temperature, Secchi depth, conductivity and DO were identified as important factors affecting the differences of phytoplankton communities in the studied lakes in Boseong River basin using non-metric multidimensional scaling (NMDS).

• Korean Journal of Microbiology
• /
• v.51 no.1
• /
• pp.81-85
• /
• 2015

Since the banning of antibiotic growth promoters (AGPs), the death of livestock has been increased, thus there is a strong demand for AGP-alternatives. Modulation of gut microbiota has been reported to affect host physiological functions and suggested to be a novel approach for developing AGP-alternatives. However, little has been understood about livestock gut microbiota compared to that of humans. We conducted preliminary study provide fundamental information regarding to regional differences in swine gut microbiota. Swine fecal samples were obtained from farms in Jeju (n=40), Gwangju (n=28), and Haenam (n=30). MiSeq was used to sequence 16S rRNA V4 region, and Mothur pipeline (Schloss et al., 2009) was used for data processing. A total of 5,642,125 reads were obtained and 3,868,143 reads were remained after removing erroneous reads. Analysis of taxonomic composition at the phylum level indicated greater abundance of Firmicutes among Jeju swine, and cluster analysis of distribution of operational taxonomic units also showed regional differences among swine gut microbiota. In addition, correlation analysis between non-metric multidimensional scaling and abundance of phyla suggested that the phyla Actinobacter, Verrucomicrobia, Firmicutes, and Fibrobacteres were driving factors for the regional differences. Livestock gut microbiota may be affected by diet and practices in farms. Our results indicated significant regional differences in swine gut microbiota, suggesting that future livestock gut microbiota studies should be designed with the regional differences in mind.

• Science of Emotion and Sensibility
• /
• v.8 no.4
• /
• pp.365-374
• /
• 2005

Pain has at least two dimensions such as somatosensory qualities and affect and patients are frequently asked to score the intensity of their pain on a numerical pain rating scale. However, the use of a undimensional scale is questionable in view of the belief, overwhelmingly supported by clinical experience as well as by empirical evidence from multidimensional scaling and other sources, that pain has multidimensions such as sensory-discrimitive, motivational-affective and cognitive-evaluative The study of pain has recently received much attention, especially in understanding its neurophysiology by using new brain imaging techniques, such as positron emission tomography(PET) and functional magnetic resonance imaging (fMRI), both of which allow us to visualize brain function in vivo. Also the new brainimaging devices allow us to evaluate the patients pain status and plan To treat patients objectively. Base4 on our findings we presented what are the new brain imaging devices and the results of study by using brain imaging devices.

• Journal of the Korean Geographical Society
• /
• v.51 no.3
• /
• pp.401-420
• /
• 2016

This study aims to investigate the changes in the occupational structure of employment in Korea during the last three decades, in which have transformed from industrialized economy to knowledge-based economy very rapidly as well as having experiences of both IMF and financial crisis. For this purpose, we analyze the trends occupational distribution and the socio-demographic characteristics of the occupational structure of employment since 1980. By applying correspondence analysis of Multidimensional Scaling(MDS) methods, we examine the inter-relationships between the employed persons by occupation and their characteristics such as gender, age group, educational attainment, industry, region. We found the occupational structure of Korea has been changed dramatically with the socio-economic transformations during the last four decades. In particular, the occupational (job) structure has been highered in general. However, it has also been dualized extremely into two groups, one is the specialized-skilled-white color jobs and the other is the simple-unskilled-blue color jobs. The results of this study could be utilized as the importation basis for the provision of labour supply and employment policy plan at the national level as well as at the local level.

• Journal of The Korean Association For Science Education
• /
• v.32 no.10
• /
• pp.1524-1536
• /
• 2012

Science attitudes affect the quality of learning, and they are considered as one of the major concerns in science education. It is necessary to analyze the proximity between concepts with science attitudes. Accordingly, this study was designed to analyze the proximity of the concept related to photosynthesis as it changed after class according to the levels of science attitudes. A survey on the concept of photosynthesis and science attitudes before and after class was conducted on 270 7th-grade students. The concept of photosynthesis was composed of 'the place of photosynthesis,' 'products of photosynthesis,' 'reactants of photosynthesis,' and 'environmental factors.' The proximity of the concept of photosynthesis was analyzed through the utilization of multidimensional scaling (MDS). The research results were as follows: (1) Students changed the proximity between concepts by acquiring concrete concepts through class. (2) The upper group in science attitudes tends to be closer to the proximity between scientific concepts through class, compared to the intermediate and lower groups. (3) In all students with entire levels of science attitudes, non-scientific concepts continued to exist even after class, and the non-scientific concepts were deemed to interfere with the proximity between scientific concepts related to photosynthesis. (4) Students turned out to be aware of the concepts related to each other in four areas associated with photosynthesis. That is, it can be said that students are closely aware of the place where photosynthesis can occur and the materials needed as well as materials generated as a result of photosynthesis and the materials needed in terms of concepts related to photosynthesis.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.5
• /
• pp.595-603
• /
• 2019

To alleviate the demand on private car that is constantly increasing, Busan Metropolitan City (BMC) has established Bus Rapid Transit (BRT) to revitalize public transportation. But there are no unified lane system between BRT and general bus stations, which makes off-lane turning general bus to contribute to congestion. And as the bottleneck phenomenon at entrance/exit accelerates the congestion, there has been huge dissatisfaction among commuting drivers. Therefore, this study identifies efficient methods to operate better through measuring civilian awareness. We evaluate both satisfaction and drawbacks on BRT service with Importance-Performance Analysis (IPA). We first distinguish the groups by the awareness on BRT and their main transit usage, and then clarify the difference between the groups. And as a result, the group who is positive to BRT and uses buses often demands improvement in bus indoor comfort and curbing jaywalking. On the other hand, group who is negative to BRT and uses private cars often demands improvement in lane changing and the moving speed of private cars. We next examines the groups with MDPREF, one method of Multidimensional Scaling (MDS). And we have clarified that the evaluating criteria and the individual attributes of the groups corresponds very well.

• Korean Journal of Ecology and Environment
• /
• v.54 no.2
• /
• pp.130-141
• /
• 2021

By reviewing previous literature, we analyzed the food sources of 20 out of 29 endangered fish species from freshwater ecosystems in South Korea. A total of 19 studies reported that food sources of 20 endangered fish species included 20 phyla, 31 classes, 58 orders, 116 families, and 154 genera. Arthropod, insecta, diptera, and chironomidae were the most fed animal food sources according to different resolution of taxa index on phylum, class, order and family. Similarity, bacillariophyta, bacillariophyceae, naviculales, and cymbellaceae were the most fed abundant plant sources. A larger number of fish species were reliant on animal food sources than plant food sources. 18 of the endangered fish preyed on arthropods, whereas only 6 species consumed bacillariophyta. To characterize the feeding groups of the 20 fish species, a hierarchical clustering analysis and non-metric multidimensional scaling analysis were conducted. The fish species were divided into two groups: 1) insectivores and 2) planktivores. A network analysis, which associated the link between endangered fishes and food sources, also revealed the same two groups. The highest hub score of food sources was for macroinvertebrates, including diptera (0.47), ephemeroptera (0.42), and trichoptera (0.38), based on the network analysis. Niche breadth was used to calculate the diversity of the food sources. Phoxinus phoxinus (0.57) showed thehighest food source diversity among the fish species, whereas Iksookimia pacifica (0.01) showed the lowest. This study will be utilized for the conservation and restoration of the endangered fish species.

• Korean Journal of Ichthyology
• /
• v.34 no.2
• /
• pp.102-112
• /
• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.

• Journal of Intelligence and Information Systems
• /
• v.29 no.1
• /
• pp.397-412
• /
• 2023

In order for social robots to take root in human life, it is important to consider the technical implementation of social robots and human psychology toward social robots. This study aimed to derive potential social robot clusters based on the emotions consumers feel about social robot appearance design, and to identify and compare important design characteristics and emotional differences of each cluster. In our study, we established a social robot emotion framework to measure and evaluate the emotions consumers feel about social robots, and evaluated the emotions of social robot designs based on the semantic differential method, an kansei engineering approach. We classified 30 social robots into 4 clusters by conducting a multidimensional scaling method and K-means cluster analysis based on the emotion evaluation results, confirmed the characteristics of design elements for each cluster, and conducted a comparative analysis on consumer emotions. We proposed a strategic direction for successful social robot design and development from a human-centered perspective based on the design characteristics and emotional differences derived for each cluster.

• Journal of Wetlands Research
• /
• v.23 no.3
• /
• pp.201-212
• /
• 2021

In wetland protection areas, a phytosociological research was conducted on willow forests, which plays an important ecological and environmental role and is the main material for ecological restoration. A total of 61 relevés were collected according to the Z-M(Zürich-Montpellier) school's method and the characteristics of plant communities and the composition of the species were identified. A total of 9 plant communities including 237 taxa were differentiated. Willow species showing the high r-NCD(relative net contribution degree) value in study areas were Salix koriyanagi, Salix chaenomeloides, Salix triandra subsp. nipponica, Salix gracilistyla and Salix pierotii. Poaceae was the most diverse in species, followed by Asteraceae, Apiaceae, Polygonaceae and Fabaceae. Life form type of willow forests in wetland protection areas was determined to be Th(therophytes)-R₅(non-clonal form)-D₄(clitochores)-e(erect form) type. The naturalized plants and invasive alien species were identified as 24 taxa and 4 taxa, respectively. Naturalized and disturbance indices were 10.1% and 41.4%, respectively. The results of the site-species ordination by Non-Metric Multidimensional Scaling(NMDS), wetland types and altitude gradient were the main ecological factors determining the spatial distribution of plant communities. Diversity index and evenness index were high in mountainous palustrine wetlands with relatively high altitude, and the disturbance index, naturalized index and appearance rate of annual plant were high in riverine and lacustrine wetlands with low altitude.