• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.185-192
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• 2013

BACKGROUND: As a result of rural exodus, aging of rural population, development of high-yield rice varieties and so on, abandoned paddy fields of South Korea have generally increased. The phytosociological studies are needed to recommend the effective vegetation management methods of abandoned paddy fields. The current study performed an analysis of vegetation characteristics by classifying plant communities for abandoned paddy fields in South Korea. METHODS AND RESULTS: A comparative analysis of syntaxonomy, synecology, and syndynamics was performed by using the Z.-M. method of phytosociology and vegetation survey which was obtained from an enumeration district of total 203 phytosociological releves of 5 regions in Gangwon-do, 5 regions in Gyeonggi-do, 2 regions in Chungcheong-do, 18 regions in Gyeongsang-do, and 10 regions in Jeolla-do. Alopecurus aequalis community, Juncus effusus var. decipiens community and Salix koreensis community were, respectively, identified as successional plant communities of the early stage, the middle stage, and the late stage in the vegetation of abandoned paddy field. Sere of abandoned paddy field can be classified, developmentally, into annual plant stage, perennial plant stage, shrub plant stage, and forest tree stage. Several kinds of dominant species rather than a distinct species were found in the middle stage of abandoned paddy field. CONCLUSION(S): In this study, changing pattern in vegetational communities of abandoned paddy field were understood. These results will provide important information for restoring and conserving the ecology of fallow ground.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.435-443
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• 2014

The aim of this study was to look for the cause of shortage of K-League spectators from a consumer's perspective and to offer solutions. For this, we offered enhancement method of the K-League spectators through dual path model based on existing relative researches. The first path involved consumer reaction to external factors of the K-League game. This path explained relational view(=we-ness) of consumers on K-League game(Hypothesis 1, 2). The second path explained personal view on K-League game. This path means consumer reaction to K-League game itself(Hypothesis 3, 4). The empirical study was based on a field survey and structural equation model. The results showed that we-ness positively affected team loyalty(Hypothesis 1) and the team loyalty positively affected spectating intentions(Hypothesis 2). It also revealed that flow of K-League game positively affected consumer satisfaction(Hypothesis 3). Finally consumer satisfaction was found to affect spectating intentions(Hypothesis 4). The significance of present study is to extend scope of research which is related with cheerleading of sports game. And this study emphasize the importance of we-ness and flow in sports game.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.310-318
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• 2013

In territorial ecosystem, soil has stored considerable amount of carbon, and it is vulnerable to weakness release much of the carbon to atmosphere. In this study, we have been effort realization and discussion to the error between inter-instruments and measurement methods, time and special variations, gap filling and separation from each source included in soil respiration, used to collect soil respiration data in various ecosystems in Korea. In conclusion, it have to collect calibration data throughout comparison test between methods and instruments because accumulated data from past and accumulating data in present did not calibrated. In predicting change of soil carbon dynamic using the model method, it needs important data such as longterm and short-term data, artificial handling data of major factor, data from various ecosystem, soil texture, soil depth etc. In company with, we should collect highly qualified data through deep consideration of present problems.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.214-224
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• 2004

A large cage system for the purpose of fishes farming in the open sea was influenced by various forces from the ocean environment. The deformation of the cage by these forces affects the safety of the cage itself, as well as that of the cultivated creatures. In this research, theoretical model was established to analyzing dynamic movement influenced by current for cage. Also, to increase the accuracy of calculations, the reduction ratio of flow speed acquired using the flume tank experiment. Applying the reduction ratio of flow speed to the numerical calculation, the calculation values were compared with the measured values in the flume tank experiment using cage model. The results were as follows ; 1. When the flow speed of the flume tank is fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of porosity ratio of netting. 2. When the porosity ratio is fixed, the increase of the velocity of flow which is passed the upper panel side is proportion to the increase of velocity of flow. 3. When the porosity ratio and the flow speed of the flume tank are fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of attack angle. 4. As a result of comparison between the underwater shape by simulation which is applying the reduction ratio of flow speed from the experiment using plane netting and that by model experiment, it was found out that the result of the simulation was very close to that of model gear within ${\pm}$ 5 % error range.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.663-670
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• 2023

Unlike previous studies that have looked at ESG management and ESG performance from a consumer perspective, this study aims to examine the relationship between attitudes toward ESG and ESG performance perception from the perspective of internal customers who are members of the organization. To this end, the impact of internal members' perceptions of the importance of each ESG area on the organization's ESG management necessity and performance perception was summarized into three research questions and the impact was identified using a structural equation model. As a result of the study, internal customers highly recognized the organization's ESG management needs when they recognized the E (environmental) and G (governance) areas as important, but there was no significant relationship with the ESG management needs in the S (social) area (Research Question 1). In addition, the relationship between the perception of importance in each ESG area and the organization's ESG management needs was found to be little different depending on internal customers' interest in ESG, the degree of ESG knowledge, and age (Research Question 2). Finally, it was found that internal customers who highly perceive the organization's ESG management needs were also positively aware of the organization's ESG performance level.

• Korean Journal of Ecology and Environment
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• v.36 no.3 s.104
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• pp.286-294
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• 2003

This study was attempted to understand seasonal dynamics of phyto- and zooplankton communities in shallow, eutrophic Lake llgam and to compare them with the PEG (Plankton Ecology Group) model. Seasonal succession pattern of phytoplankton community was similar to PEG model as Chlorophyceae and Baciliphyceae increase during spring and autumn fellowed by increase of Cyanophyceae. However, based on the cell density and biomass, a dominant phytoplankton community differed with PEG model: Cyanophyceae had been a dominant community throughout a year, except for ice-cover period during which Chlorophyceae was a dominant group. In spring, when ice melted and dissolved nutrients in water column increased, the increase of Chlorophyceae occurred: when nutrients (DIN and DIP) rapidly decreased, Cyanophyceae increase occurred. Microcystis, Oscillatoria, Lyngbya, Merismopedia were maior dominant species of Cyanophyceae and their cell density and/or biomass was the highest in October 2000 (12.9${\pm}$5.8${\times}10^5$ cells/ml, 3.5${\pm}$0.9${\times}10^3{\mu}gC/l$). Cyanophyceae biomass showed positive relationship with chlorophyll a ($r^2$ = 0.71,P< 0.001) and TP concentration ($r^2$ = 0.62, P< 0.001). Small-sized rotifers such as Keratella cochlearis, increased between March and May when Chlorophyceae increased. Both high standing crop of copepods and cladocerans, such as Diaphanosoma brachyrum and Bosmina longirostris occurred between June and September accompanied with the increase of Dinophyceae and Bacillariophyceae. There was no evidence that clear-water phase was caused by zooplankton grazing. The diversity and evenness index of phyto- and/or zooplankton increased with chlorophyll a concentration. These results suggest zooplankton grazing and limiting nutrient deficiency could lead to change of phytoplankton biomass, but not the phytoplankton community in Lake llgam.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.77-93
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• 2013

Global warming accelerates both carbon (C) input through increased forest productivity and heterotrophic C emission in forest soils, and a future trend in soil C dynamics is uncertain. In this study, the Korean forest soil carbon model (KFSC model) was applied to 1,467,458 ha of Pinus densiflora forests in Korea to predict future C dynamics under RCP 8.5 climate change scenario (RCP scenario). Korea was divided into 16 administrative regions, and P. densiflora forests in each region were classified into six classes by their stand ages : 1 to 10 (I), 11 to 20 (II), 21 to 30 (III), 31 to 40 (IV), 41 to 50 (V), and 51 to 80-year-old (VI+). The forest of each stand age class in a region was treated as a simulation unit, then future net primary production (NPP), soil respiration (SR) and forest soil C stock of each simulation unit were predicted from the 2012 to 2100 under RCP scenario and constant temperature scenario (CT scenario). As a result, NPP decreased in the initial stage of simulation then increased while SR increased in the initial stage of simulation then decreased in both scenarios. The mean NPP and SR under RCP scenario was 20.2% and 20.0% higher than that under CT scenario, respectively. When the initial age class was I, IV, V or VI+, predicted soil C stock under CT scenario was higher than that under RCP scenario, however, the countertrend was observed when the initial age class was II or III. Also, forests having a lower site index showed a lower soil C stock. It suggested that the impact of temperature on NPP was higher when the forests grow faster. Soil C stock under RCP scenario decreased at the end of simulation, and it might be derived from exponentially increased SR under the higher temperature condition. Thus, the difference in soil C stock under two scenarios will be much larger in the further future.

• Journal of Chest Surgery
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• v.36 no.8
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• pp.545-558
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• 2003

Adult respiratory distress syndrome (ARDS) is of particular interest because of its severity of the associated lung injury and its high mortality. However, the pathophysiologies of ARDS in infant and childhood groups are still not well clarified inspite of many previous investigations. To investigate the time course of pathophysiology of ARDS in infant and childhood groups, this study was designed with experimental endotoxin-induced ARDS model using young rabbits (8 week-old). Material and Method: Rabbits were divided into the control group (n=8) and the endotoxin-treated group (n=32). The endotoxin group was subdivided into 4 groups by the sampling times as 3, 6, 12 and 24 hr-groups (G- $E_{3,6,12,24,}$ each n=8). The experimental ARDS was made by a bolus injection of endotoxin (Escherichia coli serotype 055 : B5, 0.50 mg/kg) via rabbit ear vein. For evaluation of the hematologic and inflammatory markers, and superoxide dismutase (SOD) concentrations, the blood samples were taken from the heart. The bronchoalveolar lavage fluid (BALF) were obtained for analysis of the leukocytes and protein concentration. With biopsy of the lung, histopathologic changes of the lung were also evaluated. Result: In the endotoxin groups, significant leukopenia (owing to pancytopenia) occurred in 3 and 6-hr groups, which was followed by significant leukocytosis (owing to neutrophilia) in the 12 and 24-hr groups (p<0.05). Serum levels of tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and interleukin-1 $\beta$ (IL-1 $\beta$) in the endotoxin groups were higher than those of control group (p<0.05). Serum levels of superoxide dismutase (SOD) of G- $E_{3}$ and G- $E_{6}$ were higher than those of control group, whereas those of G- $E_{12}$ were lower than those of control groups (p<0.05). Total leukocyte counts and protein con-centrations in BALF were significantly elevated in the endotoxin groups compared to the control group (p < 0.05). The hemorrhagic pattern of BALF showed occurred in the endotoxin groups. The endotoxin groups (in G- $E_{6}$) had severe infiltration of inflammatory cells (lymphocyte and monocyte) in the pulmonary interstitium and parenchyma, migrations of neutrophil and eosinophil into alveolar spaces and interstitial widening, which are the evidences of acute lung injury. In the endotoxin groups, there were significant positive correlations between the BALF findings and the immunologic markers (TNF-$\alpha$, IL-1$\beta$, SOD) (p<0.05). Conclusion: Severe acute lung injury occurred in all the endotoxin-treated rabbits. The pathophysiologic findings were so progressive until 6-hr by time dependant pattern, and then recovered slowly, Variable hematologic, immuno-logic, and pathologic factors were well correlated in the development and progression of endoxin-induced lung injury. The pathophysiologic responses were sensitive and rapid in young rabbit Young rabbit seemed to be a useful experimental animal model for infant and childhood groups.roups.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1179-1186
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• 2005

Purpose : A universal standard of the birth weight for gestational age cannot be made since girth weight distribution varies with race and other sociodemographic factors. This report aims to establish the birth weight distribution curve by gestational age, specific for Korean live births. Methods : We used the national birth certificate data of all live births in Korea from January 2001 to December 2003; for live births with gestational ages 24 weeks to 44 weeks(n=1,509,763), we obtained mean birth weigh, standard deviation and 10th, 25th, 50th, 75th and 90th percentile values for each gestational age group by one week increment. Then, we investigated the birth weight distribution of each gestational age group by the normal Gaussian model. To establish final standard values of Korean birth weight distribution by gestational age, we used the finite mixture model to eliminate erroneous birth slights for respective gestational ages. Results : For gestational ages 28 weeks 32 weeks, birth weight distribution showed a biologically implausible skewed tail or bimodal distribution. Following correction of the erroneous distribution by using the finite mixture model, the constructed curve of birth weight distribution was compared to those of other studies. The Korean birth weight percentile values were generally lower than those for Norwegians and North Americans, particularly after 37 weeks of gestation. The Korean curve was similar to that of Lubchenco both 50th and 90th percentiles, but generally the Korean curve had higher 10th percentile values. Conclusion : This birth weight distribution curve by gestational age is based on the most recent and the national population data compared to previous studies in Korea. We hope that for Korean infants, this curve will help clinicians in defining and managing the large for gestational age infants and also for infants with intrauterine growth retardation.