• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.609-615
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• 2011

Forsythia saxatilis is a Korean endemic plant designated as rare and endangered by the Korea Forest Service (KFS). Growth and physiological characteristics of F. saxatilis were investigated under two different light intensities in order to figure out an appropriate growth environment for conservation and restoration of the species in its natural habitat. Shoot length, leaf size and weight, photosynthetic pigment content and photosynthetic parameters were measured for F. saxatilis grown at two experimental plots under relative light intensities (RLI) of 20% and 60% of the full sun, respectively. Fresh leaf weight of plants grown under high relative light intensities (RLI-60) exceeded that of plants grown at 20% RLI. The ratio of fresh leaf weight to leaf size at RLI-60 was 1.47 times superior comparing to that recorded at RLI-20. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were higher in plants grown at RLI-60, whereas the ratio of total chlorophyll to carotenoid content was higher in the leaves at RLI-20. Photosynthetic rate, stomatal conductance and transpiration rate at RLI-60 were, respectively, 2.5, 2.65 and 1.79 times higher comparing to those recorded at RLI-20. Water use efficiency, however, was higher at RLI-20. The chlorophyll/nitrogen ratio was 1.83 times higher at RLI-20 than at RLI-60. In contrast, the ratio of net photosynthesis to chlorophyll content at RLI-60 was 2.58 times higher than that of RLI-20. In conclusion, light intensity might be the major factor affecting growth and physiological characteristics of F. saxatilis grown under canopy of tall tree species.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.83-100
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• 2020

This study evaluated the accuracy of soil moisture and evapotranspiration by calculating the hydrological parameters in Korean peninsula using Land Information System(LIS) developed by US NASA. We used Noah-MP surface model to calculate hydrological parameters, and used MERRA2(Modern-Era Retrospective analysis for Research and Applications, Version 2) for hydrological forcing data. And, International Geosphere-Biosphere Program(IGBP) and University of Maryland(UMD) land cover maps were applied to compare the output accuracy, and Automated Synoptic Observing System(ASOS) of KMA was used as ground observation data. In order to evaluate the accuracy of the output data, the correlation coefficient(CC), BIAS, and efficiency factor (NSE, Nash-Sutcliffe Efficiency) were analyzed with soil moisture and evapotranspiration by ASOS ground observation data. As a result, the correlation coefficient of soil moisture using IGBP was 0.56 on average, and evapotranspiration was about 0.71. On the other hand, soil moisture using UMD was 0.68 on average and evapotranspiration was about 0.72, and the correlation coefficient by UMD was evaluated as high accuracy compared to the results by using IGBP. The correlation coefficient of soil moisture was an average of 0.68 and evapotranspiration was an average of 0.72 when MERRA2 was used as hydrological forcing data. On the other hand, the soil moisture applied with ASOS was an average of 0.66, and evapotranspiration was an average of 0.72. It is judged that the ASOS point data was reanalyzed as 0.65°× 0.5°grids, which is the same spatial resolution with MERRA2, resulting in differences in accuracy depending on the region.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.85-105
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• 2021

In this study, a case study was conducted on Advanced Nano Products Co.,Ltd, a company that was established in 2000 and has the core technology to produce and commercialize nano materials and ultrafine nano powders based on nano technology. Deviating from the general case study, a case study analysis frame was set based on the theory of technology management and industry-university cooperation theory, and cases were analyzed. In this case study, Advanced Nano Products Co.,Ltd. was analyzed from two analytical perspectives: the establishment of a Management Of Technology system within the company and the Industry-Academic Cooperation activity. Based on this theoretical-based analysis framework, company visit interviews and related data research and analysis were conducted. As a result of the study of the case company, it was possible to derive how the technology management and industry-university cooperation affect the growth stage of the company as follows. First, the strategic use of technology management is an important factor in strengthening the competitive advantage and core competencies of venture companies, and for survival and growth of startups in the early stages. Second, strategic use of technology management and patents and establishment of a patent management system are a part of business strategy and play a pivotal role in corporate performance. Third, the human and material infrastructure of universities affects the growth of companies in the early stage of start-up, and the high utilization of industry-university cooperation promotes the growth of companies. Fourth, continuous industry-academic cooperation activities in the growth and maturity stages of a company's growth stage are the basis for activating external exchanges and building networks. Lastly, technology management and industry-university cooperation were found to be growth factors for each growth stage of a company. In order for a company to develop continuously from the start-up to the growth and maturity stages, it is necessary to establish a technology management system from the beginning and promote strategic technology management activities. In addition, it can be said that it is important to carry out various industry-academic cooperation activities outside the company. As a result of the case analysis, it was found that Advanced Nano Products Co.,Ltd, which performed these two major activities well, overcame the crisis step by step and continued to grow until now. This study shows how the use of technology management and industry-academic cooperation creates value in each growth stage of technology-based venture companies. In addition, its active use will play a big role in the growth of other venture companies. The results of this case study can be a valid reference for growth research of technology start-up venture companies and related field application and utilization.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.163-173
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• 2022

Climate change is a key factor that greatly influences changes in the biological seasons and geographical distribution of species. In the ecological field, the BioClimatic predictor (BioClim), which is most related to the physiological characteristics of organisms, is used for vulnerability assessment. However, BioClim values are not provided other than the future period climate average values for each GCM for the Shared Socio-economic Pathways (SSPs) scenario. In this study, BioClim data suitable for domestic conditions was produced using 1 km resolution SSPs scenario detailed data produced by Rural Development Administration, and based on the data, a species distribution model was applied to mainly grow in southern, Gyeongsangbuk-do, Gangwon-do and humid regions. Appropriate habitat distributions were predicted every 30 years for the base years (1981 - 2010) and future years (2011 - 2100) of the Acer pictum subsp. mono. Acer pictum subsp. mono appearance data were collected from a total of 819 points through the national natural environment survey data. In order to improve the performance of the MaxEnt model, the parameters of the model (LQH-1.5) were optimized, and 7 detailed biolicm indices and 5 topographical indices were applied to the MaxEnt model. Drainage, Annual Precipitation (Bio12), and Slope significantly contributed to the distribution of Acer pictum subsp. mono in Korea. As a result of reflecting the growth characteristics that favor moist and fertile soil, the influence of climatic factors was not significant. Accordingly, in the base year, the suitable habitat for a high level of Acer pictum subsp. mono is 3.41% of the area of Korea, and in the near future (2011 - 2040) and far future (2071 - 2100), SSP1-2.6 accounts for 0.01% and 0.02%, gradually decreasing. However, in SSP5-8.5, it was 0.01% and 0.72%, respectively, showing a tendency to decrease in the near future compared to the base year, but to gradually increase toward the far future. This study confirms the future distribution of vegetation that is more easily adapted to climate change, and has significance as a basic study that can be used for future forest restoration of climate change-adapted species.

• Composites Research
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• v.36 no.1
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• pp.1-15
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• 2023

Demand for energy consumption reduction is increasing according to the development expectations of future mobility. Lightweight structural materials are known as a method to reduce greenhouse gas emissions and improve energy efficiency. In particular, fiber reinforced polymer composite (FRP) is attracting attention as a material that can replace existing metal alloys due to its excellent mechanical properties and light weight. In this paper, industrial applications and research trends of carbon fiber reinforced composites (CFRP, carbon FRP) and self-reinforced composites (SRC) were reviewed based on the reinforcement, polymer matrix, and manufacturing process. In order to overcome the expensive process cost and long manufacturing time of the epoxy resin-based autoclave method, which is mainly used in the aircraft field, mass production of CFRP-applied electric vehicles has been reported using a high-pressure resin transfer molding process including fast-curing epoxy. In addition, thermoplastic resin-based CFRP and interface enhancement methods to solve the recycling issue of carbon fiber composites were reviewed in terms of materials and processes. To form a perfect matrix-reinforcement interface, which is known as the major factor inducing the excellent mechanical properties of FRP, studies on SRC impregnated with the same matrix in polymer fibers have been reported. The physical and mechanical properties of SRC based on various thermoplastic polymers were reviewed in terms of polymer orientation and composite structure. In addition, a copolymer matrix strategy for extending the processing window of highly drawn polypropylene fiber-based SRC was discussed. The application of CFRP and SRC as lightweight structural materials can provide potential options for improving the energy efficiency of future mobility.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.1-19
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• 2023

In Korea, excessive vegetation in rivers made up of sand and gravel is emerging as a nationwide problem, which is attributed to increased spring precipitation and decreased annual precipitation. Therefore, this study was conducted for the purpose of identifying the effect of changes in precipitation patterns on river vegetation in Namcheon, Gyeongju, and analyzing the area of vegetation and ecological characteristics. As a result of the study, the amount of monthly precipitation in the summer of Namcheon decreased after 2007, and the area of vegetation increased continuously compared to the area of the sandbank. The proportion of naturalized plants increased steadily when precipitation continued to a level that did not cause flooding, but the area occupied by naturalized plants was small. Also, when the water level is maintained, the species diversity is low due to the dominance of a single species, and the dominant species was mainly native plants. Dominance of native plants inhibited the growth of naturalized plants, but the vegetation area increased even more. Therefore, it is necessary to manage the spread of vegetation itself rather than the division of native plants and naturalized plants in order to eliminate the active growth and prosperity of river vegetation. High water levels and continuous flooding caused by torrential rains in summer disturbed the plant communities, and vegetation formed afterwards was mainly native plants. Such flooding in river ecosystems is a positive factor for the emergence of native plants and over-formed vegetation communities, so it should be considered when establishing a vegetation management plan.

• Analyses & Alternatives
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• v.7 no.1
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• pp.229-258
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• 2023

For the main countries of the Asia-Pacific region, the United States, China and Russia, a situation of "new normality" is emerging. Moreover, for each of the countries, this "new normality" has its own meaning. For the United States, this is an aggravation of the military confrontation with China in the Taiwan Strait. For China, this is an increase in the degree of rivalry with the United States and a slowdown in the pace of economic development with a very high probability of their decline in the future. For Russia, this is an almost complete curtailment of relations with the United States against the background of a special military operation and imposed sanctions. These nuances, in addition to the results of the 20th CPC Congress, will determine the main trends in Sino-American and Sino-Russian relations. It seems that China's attitude towards Russia will not change against the background of the Ukrainian crisis. Beijing will maintain a position of "benevolent neutrality" towards Moscow. At the same time, the balance between "goodwill" and "neutrality" may vary depending on the scope of Sino-Russian cooperation. For example, in the economic sphere, Chinese companies will be afraid to cooperate with Russian partners for fear of secondary sanctions. However, in general, Russia will retain its importance for China as the strongest anti-American pole. In relations with the United States, China will continue to firmly defend its interests, while at the same time not excluding the normalization of relations with Washington in certain areas of cooperation: strategic stability, non-traditional threats, ecology, etc. In general, the decisions of the 20th CPC Congress do not allow us to say either in favor or against the idea of China's readiness to resume dialogue with the United States in the post-congress period. Sino-American relations, as noted above, have their own logic and will probably continue to develop within its framework. However, so are Sino-Russian relations. Within the framework of these logics, Beijing seems to continue to balance between the two vectors of its foreign policy. On the one hand, this is the development of bilateral cooperation with Russia in order to strengthen its own negotiating positions in the confrontation with the United States: military cooperation with an emphasis on joint exercises, political cooperation based on anti-Americanism, economic cooperation with an eye to the risks of secondary sanctions. On the other hand, it is unacceptable for China to recognize the collapse of Ukraine, the inadmissibility of a direct military clash with the United States and the extreme undesirability of further aggravation of relations with the United States on the factor of Chinese friendship with Russia.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.157-163
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• 2019

Purpose: To investigate the incidence and associated factors of delirium after orthopedic surgery. Materials and Methods: A total of 2,122 cases, who were older than 20 years and underwent orthopedic surgery at a single medical center during a one year period were included. Among them, 132 patients who were diagnosed with delirium after surgery under the Diagnostic and Statistical Manual of Mental Disorders-V criteria and medicated under the consultation of a psychiatrist were included in the study The differences in the incidence of delirium and several affecting factors were analyzed. Results: The overall incidence of delirium after surgery was 6.2% (132 in 2,122 cases). The mean age of the delirium group was 77.4 years (range, 54-92 years), which was higher than that of the non-delirium group (58.1 years). The percentage of women in the delirium group was 63.6% (84 in 132 cases), which was higher than that of the women in the non-delirium group (49.0%). The incidence of delirium after surgery was 9.3% (85 in 916 cases) due to trauma and 3.9% (47 in 1206 cases) due to disease. The incidence of postoperative delirium according to the surgical region was 29.2% (7 in 24 cases) in two or more regions, 13.7% (72 in 526 cases) in the hip, and 9.6% (14 in 146 cases) in the spine, 3.5% (20 in 577 cases) in the knee-lower leg, 2.5% (5 in 199 cases) in the foot-ankle, 2.4% (11 in 457 cases) in the shoulder-elbow, and 1.6% (3 in 189 cases) in the forearm-wrist-hand. Delirium occurred more rapidly in women and surgery due to disease, and the duration of delirium was longer in patients with dementia and major depressive disorders. Conclusion: The incidence of postoperative delirium was high in cases of surgery due to trauma and in cases of surgery in two or more sites. The incidence of postoperative delirium according to a single surgical region was higher in the order of the hip, spine, and knee. Active intervention is needed regarding the correctable risk factor.

• Korea Science and Art Forum
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• v.34
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• pp.327-337
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• 2018

Korea is rapidly becoming an aging society as much as it takes the first place among OECD countries, and as the life expectancy of Korea gradually increases, the proportion of the elders in society increases. Accordingly, the happiness of the elders is contributed to the overall social atmosphere and happiness, however, the lower quality of life of the elders due to physical, psychological and social changes can be developed into social problems such as depression and rising suicide rate. As a result, there is a social interest in improving the quality of life and satisfaction of the elders, and the senior citizen center is receiving renewed attention as a form of welfare facility that can play a pivotal role in the social activities of the elders. In recent years, efforts to improve the environment of the senior citizen center have been made due to the growing role of it, however, there is a controversy over whether the quality of the indoor environment is user-friendly or not due to the limitations of material resources and human resources. It is considered that the quality of the color environment should be improved in the senior citizen center in the way that the color environment is not only an indoor environmental factor which gives high psychological and mental effects to users but also a way to improve the environmental satisfaction at the lowest cost. Previous studies on the facilities related to the elders have been actively carried out, but they were very sporadic and there was very little information about the color environment in the related laws or in the guideline presented by cities. It is necessary to integrate guidelines that are scattered within a comprehensive range without any specific target in order to grasp the current status of the color environment and to properly evaluate it. In addition, considering that the senior citizen center is an important leisure facility for the elders that functions in a residential area with a nationwide network, the results of this study are expected to contribute to the environmental improvement of existing senior citizen center which will be activated in the future by enabling the improvement of psychological satisfaction of the elders.

• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.378-387
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• 2023

Petrochemical is an energy consuming industry that consumes about 30% of total industrial energy consumption and is a representative carbon dioxide (CO₂) emission source. Among them, the Naphtha Cracking Center (NCC), which produces ethylene, propylene, propane and mixed C4, consumes large amounts of energy and emits significant amounts of CO₂. For this reason, an integrated techno economic- environmental impact assessment aimed at reducing energy consumption and environmental impact factors is necessary to ensure efficiency in terms of economics and environment. This study aims to analyze the efficiency of the heat exchanger network used in the existing NCC base on the pinch analysis and select an improvement plan that can reduced energy consumption. In order to reduces the utility consumption in the process, an optimal heat exchanger network considering the high-temperature and low-temperature stream was derived, and the economic evaluation was conducted by considering the trade-off between the reduction in utility consumption and the increase in heat exchanger installation cost. In addition, an environmental impact assessment was conducted on the reduced CO₂ emission in consideration of the environmental aspect, and the economic environmental impact assessment used the payback period to recover the invested funds to come up with an energy saving plan that can be applied based on the actual process. As a result of considering the economic-environmental impact assessment, when the environmental impact assessment was not considered, it was 4.29 months, 3.21 months, and 3.39 months for each case, and when considering the environmental impact assessment, it was 4.24 months, 3.17 months, and 3.35 months for each case. These results appeared equally both when the environmental impact assessment was not include and when it was include. In addition, a sensitivity analysis was conducted for each case to determine how important factors affect the payback period. As a result of the sensitivity analysis, the cost of the heat exchanger was identified as a major factor influencing the overall cost.