• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.112-123
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• 2022

To assess the influence of environmental factors on the phytoplankton community structure and total phytoplankton biomass during four seasons in 2014, we investigated the abiotic and biotic factors at 25 stations in the Busan coastal region. The phytoplankton community and total phytoplankton biomass were strongly dependent on the discharge from the Nakdong River, and the high density of phytoplankton was related with the introduction of the Tsushima Warm Current (TWC), particularly in the thermohaline fronts of the fall season. The relationship between the salinity and nutrient (Dissolved inorganic nitrogen=DIN: R²=0.72, p<0.001 and Dissolved inorganic silicon=DSi: R²=0.78, p<0.001) highly correlated with the river discharge, implying that those nutrients have played a crucial role in the growth of diatom and cryptophyta. The total phytoplankton biomass was highest in the summer followed by autumn, spring, and winter. Diatom and cryptophyta species were dominant species during the four seasons. Additionally, there were strong positive correlations between Chlorophyll a and total phytoplankton biomass (R²=0.84, p<0.001), cryptophyta (R²=0.76, p<0.001) and diatom (R²=0.50, p<0.001), respectively. In particular, we found that there were significant differences in the nutrients, phytoplankton community compositions, and total phytoplankton biomass between the inner and the outer coastal region of Busan, depending on the amount of river discharge from the Nakdong River, particularly during rainy seasons. Therefore, the seasonal change of TWC and river discharge from the Nakdong River serve an important role in determining phytoplankton population dynamics in the Busan coastal region.

• Knowledge Management Research
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• v.24 no.1
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• pp.245-271
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• 2023

The change to the data economy requires a new analysis beyond ordinary research in the management field. Data matching refers to a technique or processing method that combines data sets collected from different samples with the same population. In this study, statistical matching was performed using random hotdeck and Mahalanobis distance functions using 2020 Survey of Korea Venture Firms and 2020 Korea Innovation Survey datas. Among the variables used for statistical matching simulation, the industry and the number of workers were set to be completely consistent, and region, business power, listed market, and sales were set as common variables. Simulation verification was confirmed by mean test and kernel density. As a result of the analysis, it was confirmed that statistical matching was appropriate because there was a difference in the average test, but a similar pattern was shown in the kernel density. This result attempted to expand the spectrum of the research method by experimenting with a data matching research methodology that has not been sufficiently attempted in the management field, and suggests implications in terms of data utilization and diversity.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.10-18
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• 2022

This study analyzed the relationship between the community structure of benthic macroinvertebrates and habitat changes in open estuaries among the sites included in the national estuary monitoring program. The estuary survey was conducted under the "Guidelines for Investigation and Evaluation of Biometric Networks" and classified by sea area, 80 places in the East Sea, 102 places in the South Sea, and 19 places in the West Sea were investigated. In a total of 201 open estuaries, benthic macroinvertebrates were identified with 4 phyla, 9 classes, 41 orders, 139 families, 269 species and 196 species in the East Sea, 182 species in the South Sea, and 90 species in the West Sea. The highest population densities were Insecta in the East Sea, the Malacostraca in the South Sea, and the Annelida in the West Sea. Through SIMPER analysis, species contributing to the similarity of benthic macroinvertebrates communities in each sea area were identified. Some species greatly influenced the similarity of clusters. The benthic community in the East Sea was affected by the salinity, so the contribution rate of freshwater species was high. On the other hand, the benthic communities of the South and West Seas showed species compositions are influenced by the substrate composition. As results, the benthic macroinvertebrate community in Korean estuaries was impacted by salinity and substrate simultaneously, and the close relationship with geographical distance was not observed. The result of this study is expected to be used to respond to environmental changes by identifying and predicting changes in the diversity and distribution of benthic macroinvertebrates in Korea estuaries.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.1-8
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• 2019

Globally, the elderly population is increasing rapidly, which means that the number of deformity correction operations for elderly spine deformity patient has increased. On the other hand, for aged patients with deformity correction operation, preoperative considerations to reduce the complications and predict a good clinical outcome are not completely understood. First, medical comorbidity needs to be evaluated preoperatively with the Cumulative Illness Rating Scale for Geriatrics or the Charlson Comorbidity Index scores. Medical comorbidities are associated with the postoperative complication rate. Managing these comorbidities preoperatively decreases the complications after a spine deformity correction operation. Second, bone densitometry need to be checked for osteoporosis. Many surgical techniques have been introduced to prevent the complications associated with posterior instrumentation for osteoporosis patients. The preoperative use of an osteogenesis inducing agent - teriparatide was also reported to reduce the complication rate. Third, total body sagittal alignment need to be considered. Many elderly spine deformity patients accompanied degenerative changes and deformities at their lower extremities. In addition, a compensation mechanism induces the deformed posture of the lower extremities. Recently, some authors introduced a parameter including total body sagittal alignment, which can predict the clinical outcome better than previous parameters limited to the spine or pelvis. As a result, total body sagittal alignment needs to be considered for elderly spine deformity patients after a deformity correction operation. In conclusion, for elderly spine deformity patients, medical comorbidities and osteoporosis need to be evaluated and managed preoperatively to reduce the complication rate. In addition, total body sagittal alignment needs to be considered, which is associated with better clinical outcomes than the previous parameters limited to the spine or pelvis.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.1-6
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• 2017

Purpose: To retrospectively compare minimally invasive percutaneous plate osteosynthesis (MIPPO) with open plate fixation for the treatment of clavicle midshaft fracture. Materials and Methods: Between November 2011 to May 2014, 40 cases that were followed for more than 1 year-among all cases of MIPPO and open plate fixation-were analyzed. The study population was divided into two groups: group A included 20 cases of MIPPO and group B included 20 open plate fixation cases. The comparative analysis between the two groups was based on the operative time, bone union, functional evaluation (American Shoulder and Elbow Society score), incision length, pain relief (visual analogue scale, VAS), and complication. Results: The bone union was successful for all the cases, and the functional evaluation scores of the shoulder joint were satisfactory for both groups (p>0.05). The operative time was 47.5 minutes and 58.7 minutes for group A and B, respectively (p<0.05). The incision length for group A was 6.2 cm and that for group B was 10.7 cm with statistical significance (p<0.05). Pain relief (VAS) after surgery for group A showed a quick recuperation in the early stages. For complications, there were 2 cases of dysesthesia and 1 case of malunion due to metal fixation failure in group A. There were 6 cases of dysesthesia and 2 cases of cosmetic problem due to hypertrophic scar in group B. Conclusion: Surgical results of clavicle shaft fracture were satisfactory for both groups, but group A had advantages of shorter operative time, minimal incision length, and better pain relief in the early stages compared with group B. However, we need further evaluations with long-term follow-up results and complications, such as malunion and exposure on radiation.

• Korean Association of Arts Management
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• no.51
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• pp.35-73
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• 2019

The purpose of this study is to investigate the effects of culture and arts activities (experience, type, frequency) and participation motivation on subjective well-being and to investigate the mediating effects of learning motivation. For this study, the subject is limited to adults who are leading consumers of culture and art activities can decide what activity to do. By survey, data from 1,000 respondents are used for analysis after applying proportional sampling based on the proportion of sex and age indicated in the population statistics. Exploratory factor analysis and reliability analysis were conducted based on the collected data using SPSS v.22.0. The results obtained from the empirical analysis are as follows. First, regarding culture and art activities (experience, type, frequency) and subjective well-being, the results are as follows. H1. Those who experienced culture and arts activities have higher subjective well-being than non-experienced ones. H2. Participating in culture and art activity increases subjective well-being more than just spectating culture and art programs. H3. Heavy participants in culture and art activities have higher subjective well-being than lighter participants. These results indicate that culture and art activities are important variables that have a positive effect on subjective well-being. Therefore, participating in culture and art activities may be an appropriate way to enhance subjective well-being because they are life experiences that individuals can experience in their daily lives. Second, H4. internal motivation and external motivation, sub-factors of participation motivation in culture and art activities, have a positive effect on subjective well-being, and amotivation has a negative effect on subjective well-being. Therefore, in order to improve subjective well-being, it is important to strive to lower amotivation and increase internal and external motivation. Third, H5. learning motivation has a partial mediating effect on the relationship between participation motivation in culture and art activities and subjective well-being. This result suggests that culture and art activities and education might be helpful for subjective well-being when they are conducted together since participation motivation in culture.

• Korea Science and Art Forum
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• v.29
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• pp.319-331
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• 2017

South Korea has entered the age of aging society since the elderly population over 65 reached 13.1% in 2015. This increase rate is the fastest in the OECD members. as a part of the precaution, the Korean government has enforced the long term care insurance from July 2008 and the increase of related nursing homes until 2015 was 220.2% which is rapid and quantitative. It was natural that quantitative expansion leads to qualitative improvement. With regard to service environment conditions, color environment draws attention as one of the most effective measures. color environment supports nursing home's spatial functions and the aged class is subject to the research as the potential customers. This study aims to understand color environment, conduct surveys for color preference and attitude toward color environment, and suggest directions for color environment plan. The ultimate goal is to improve the quality of Korean nursing home environment. It studied definition, state, color environment and space functions of nursing homes as well as the preceding researches. With 100 people over 60s in Busan and Gyeongnam area (52 male and 48 female), the survey examined attitudes for color environment and color preference by space functions in nursing home. The research method is as follows. First, as a result of the consciousness survey on color environment in elderly nursing home, it considers service (37%), medical service (20%), and location (19%) heavily in order. color environment plan is not recognized significantly. However, the need of indoor color plan in the elderly nursing homes has "agree (32%) and "strongly agree (25%), which suggests that color introduction is required to the nursing homes. Second, the indoor coloration for the elderly nursing homes has various color preferences. The color preference order for bedroom was R, P, and G but this order changes in nursing space (program room) to G, R, and Y. The communal space such as lobby prefers R, G and Y in order. R color was preferred in general.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.2
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• pp.135-145
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• 2023

Aggregate is used to produce stable materials like concrete and asphalt and is fundamental to meet the social needs of housing, industry, road, energy and health. A total of 42.35 billion tons of aggregate were produced in 2021 worldwide, an increase of 0.91% compared to the previous year. Among them, 2 billion tons were produced in China, India, European Union and United States, making up to 71.75% of the share. South Korea has witnessed a constant increase in aggregate production, overtaking Mexico and Japan for seventh place with 390 million tons and 0.85% of the share. The industrial sand and gravel produced globally amounted to 352.66 million tons. The top seven countries with the highest production were China, United States, Netherlands, Italy, India, Turkey and France, and their production exceeded 10 million tons and held a share of 74.69%. Exports of natural rock recorded $21.68 billion in 2021, increased by $2.3 billion compared to the previous year, while exports of artificial rock increased by $2.66 billion to $13.59 billion. Exports of sand reached $1.71 billion with United States, Netherlands, Germany and Belgium being the four countries with the highest exports of sand. The four countries exported more than $100 million in sand and took up 57.70% of the total amount. Exports of gravel totaled $2.75 billion, with China, Norway, Germany, Belgium, France and Austria in the lead, making up to 48.30% of the total share. The aggregate quarry started to surge in the 1950s due to the change in people's lifestyle such as population growth, urbanization and infrastructure delvelopment. Demand for aggregate is also skyrocketing to prevent land reclamation and flood caused by sea-level rise. Demand for aggregate, which was around 24 gigatons in 2011, is expected to double to 55 gigatons in 2060. However, it is likely that aggregate extraction will heavily damage the ecosystem and the world will eventually face a shortage of aggregate followed by tense social conflict.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.172-186
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• 2023

Small ponds, which exhibit unstable succession pattern of plankton community, are less well studied than large lakes. Recently, the importance of small ponds for local biodiversity conservation has highlighted the necessity of understanding the dynamics of biological community. In the present study, we collected zooplankton from three small reservoirs with monthly basis and analyzed their seasonal dynamics. To understand the complicated zooplankton community dynamics of small reservoirs, we categorized zooplankton species into four groups (LALF Group, Low Abundance Low Frequency; LAHF Group, Low Abundance High Frequency; HALF Group, High Abundance Low Frequency; HAHF Group, High Abundance High Frequency) based on their occurrence pattern (abundance and frequency). We compared the seasonal pattern of each group, and estimated community diversity based on temporal beta diversity contribution of each group. The result revealed that there is a relationship between groups with the same abundance but different occurrence frequencies, and copepod nauplii are common important component for both abundance and frequency. On the other hand, species included with LALF Group throughout the study period are key in terms of monthly succession and diversity. LALF Group includes Anuraeopsis fissa, Hexarthra mira and Lecane luna. However, groups containing species that only occur at certain times of the year and dominate the waterbody, HALF Group, hindered to temporal diversity. The results of this study suggest that the species-specific occurrence pattern is one key trait of species determining its contribution to total annual biodiversity of given community.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.129-142
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• 2023

This study analyzed the ratio of carbon monoxide (CO) and carbon dioxide (CO₂), CO and nitrogen dioxide (NO₂) for cities and regionsin Korea and China using column-averaged carbon dioxide dry-air mole fraction (XCO₂) of the Orbiting Carbon Observatory-2/3, CO and NO₂ vertical column density (named XCO, XNO₂ in thisstudy) of TROPOspheric monitoring instrument from April 2018 to April 2022, and presented the relationship between socioeconomic indicators (population, number of vehicles, Gross Regional Domestic Product) and ratio, and differences in characteristics between Korea and China. First, CO₂ and CO were analyzed after calculating ΔXCO₂ and ΔXCO removing the background value and trend line due to the difference in atmospheric residence time of three gaseous substances (CO₂, CO, and NO₂). Comparing the three values by regions, ΔXCO and ΔXCO₂ were relatively higher in China and XNO₂ were higher in Korea and the ratio of both values (ΔXCO/ΔXCO₂, ΔXCO/XNO₂) was higher in China than in Korea. ΔXCO/ΔXCO₂, ΔXCO/XNO₂ and socioeconomic indicators have a positive correlation suggesting that the concentration of air pollutants and greenhouse gases is higher as the city is large and the economic activity is active. Regarding the differences in the ratio characteristics of Korea and China, the relationship between ΔXCO and ΔXCO₂ showed a negative correlation in Korea and a positive correlation in China. When the relationship between ΔXCO and XNO₂ was examined for summer and winter, the change of ΔXCO by season was not significant in Korea, whereasthe change of ΔXCO and XNO₂ by season waslarge in China resulting in the relationship between two countries appeared differently. These results suggest that seasonal variability and national emission characteristics should be considered in the process of analyzing the ratio of greenhouse gases to air pollutants.