• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.23-32
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• 2019

Increasing crop production with the same amount of resources is essential for enhancing the economy in agriculture. The first prerequisite is to understand relationships between the resources. The concept of WEF (Water-Energy-Food) nexus analysis was first introduced in 2011, which helps to interpret inter-linkages among the resources and stakeholders. The objective of this study was to analyze energy-water nexus in greenhouse cultivation by estimating reference evapotranspiration and heating load. For the estimation, this study used the physical model to simulate the inside temperature of the agricultural greenhouse using heating, solar radiation, ventilated and transferred heat losses as input variables. For estimating reference evapotranspiration and heating load, Penman-Monteith equation and seasonal heating load equation with HDH (Heating Degree-Hour) was applied. For calibration and validation of simulated inside temperature, used were hourly data observed from 2011 to 2012 in multi-span greenhouse. Results of the simulation were evaluated using $R^2$, MAE and RMSE, which showed 0.75, 2.22, 3.08 for calibration and 0.71, 2.39, 3.35 for validation respectively. When minimum setting temperature was $12^{\circ}C$ from 2013 to 2017, mean values of evapotranspiration and heating load were 687 mm/year and 2,147 GJ/year. For $18^{\circ}C$, Mean values of evapotranspiration and heating load were 707 mm/year and 5,616 GJ/year. From the estimation, the relationship between water and heat energy was estimated as 1.0~2.6 GJ/ton. Though additional calibrations with different types of greenhouses are necessary, the results of this study imply that they are applicable when evaluating resource relationship in the greenhouse cultivation complex.

• Journal of Korea Water Resources Association
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• v.52 no.7
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• pp.475-482
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• 2019

Subseasonal-to-Seasonal (S2S) prediction information which have 2 weeks to 2 months lead time are expected to be used through many parts of industry fields, but utilizability is not reached to expectation because of lower predictability than weather forecast and mid- /long-term forecast. In this study, we used multi-layer perceptron (MLP) which is one of machine learning technique that was built for regression training in order to improve predictability of S2S precipitation data at South Korea through post-processing. Hindcast information of ECMWF was used for MLP training and the original data were compared with trained outputs based on dichotomous forecast technique. As a result, Bias score, accuracy, and Critical Success Index (CSI) of trained output were improved on average by 59.7%, 124.3% and 88.5%, respectively. Probability of detection (POD) score was decreased on average by 9.5% and the reason was analyzed that ECMWF's model excessively predicted precipitation days. In this study, we confirmed that predictability of ECMWF's S2S information can be improved by post-processing using MLP even the predictability of original data was low. The results of this study can be used to increase the capability of S2S information in water resource and agricultural fields.

• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.141-148
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• 2019

When simulating the daily rainfall amount by existing Markov Chain model, it is general to simulate the rainfall occurrence and to estimate the rainfall amount randomly from the distribution which is similar to the daily rainfall distribution characteristic using Monte Carlo simulation. At this time, there is a limitation that the characteristics of rainfall intensity and distribution by time according to the rainfall duration are not reflected in the results. In this study, 1-day, 2-day, 3-day, 4-day rainfall event are classified, and the rainfall amount is estimated by rainfall duration. In other words, the distributions of the total amount of rainfall event by the duration are set using the Kernel Density Estimation (KDE), the daily rainfall in each day are estimated from the distribution of each duration. Total rainfall amount determined for each event are divided into each daily rainfall considering the type of daily distribution of the rainfall event which has most similar rainfall amount of the observed rainfall using the k-Nearest Neighbor algorithm (KNN). This study is to develop the limitation of the existing rainfall estimation method, and it is expected that this results can use for the future rainfall estimation and as the primary data in water resource design.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.1-10
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• 2018

For local festivals to be successful, it is important to cooperate with various entities and effectively utilize festival-related resources. Recently, many efforts have been made to improve the operation and management performance of local festivals in Korea, but systematic management and IT support have been insufficient. In this study, the factors affecting the IT governance of local festivals were derived through a literature review and the relationship to the festival performance was analyzed empirically. A survey was conducted with local festival organizers and stake holders, and the research model was verified using the regression analysis with total 109 samples. According to the results of the analysis, it was confirmed that marketing, processes and service management have a significant effect on festival performance within IT governance. The effect of festival performance on resource management was not statistically significant. This study demonstrates that the systematic operation and management of local festivals using IT governance is necessary for local festivals. It will be more meaningful if further study discuss the IT utilization guidelines and success cases through the innovative use of IT for local festivals.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1127-1134
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• 2018

According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), climate change increases the frequency of abnormal weather phenomenon. As the frequency of abnormal weather phenomenon increases, frequency of disasters related to water resources such as floods and droughts also increases. Drought is the main factor that directly affects water supply. Recently, the intensity of drought and the frequency of drought occurrence have increased in Korea. So, there is a need for water resource securing technology for stable water supply. Korean Water Plan mentioned that water reserves concept is necessary for stable water supply. Most multi-purpose reservoirs in Korea have emergency storage in addition to conservation storage used for water supply. However, there is no clear use standard for emergency storage. This study investigated the use of reservoir reserves for stable water supply. In order to consider the climate change impact, the AR5-based hydrological scenario was used as inflow data for the reservoir simulation model. Reservoir simulations were carried out in accordance with the utilization conditions of emergency storage and water supply adjustment standard. The optimal reserves for each multi-purpose reservoirs was estimated using simulation results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.111-120
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• 2019

This study examined the mediating effects of perceived organizational support (POS) on the relationship between the person-job fit and job satisfaction of service workers. POS is divided into socioemotional POS and instrumental POS. To achieve the research purpose, a questionnaire survey was conducted on workers in charge of service jobs in domestic companies through an on-line survey system and finally, the results of 281 respondents were analyzed to verify the hypothesized research model with an 80.3% effective recovery rate. The findings are as follows. First, the person-job fit has positive effects on job satisfaction and POS. Second, among the sub-constructs of POS, socioemotional support has mediating effects, but instrumental support has no mediating effects on the relationship between person-job fit and job satisfaction. Based on the results of this study, this study suggests theoretical and practical implications for the human resource development and management of service workers. Overall, changes in the recruitment system, which can judge the person-job fit of employees who perform emotional labor facing customers, organizational culture and personnel system for establishing socioemotional support system, and compensation and workforce development system, are needed to enhance the job satisfaction of service workers.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.101-111
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• 2021

Irregular workers, which have recently caused various socio-economic issues and conflicts, generally have low loyalty to the organization and job satisfaction due to anxiety about employment. As a way to improve this, this study attempted to analyze the effect of organizational communication satisfaction of irregular workers on job satisfaction and organizational commitment. Among the 7th Human Capital Companies panel survey data, irregular workers survey data were collected and analyzed using the structural equation model analysis. The results were as follows: First, it was analyzed that organizational communication recognized by irregular workers had a positive(+) effect on job satisfaction and organizational commitment. Second, it was analyzed that job satisfaction had a positive(+) effect on organizational commitment. Third, it was analyzed that job satisfaction plays a mediating role in the relationship between communication satisfaction and organizational commitment. This study is significant in that it expanded the research subject to irregular workers from the existing service industry-oriented research, and that it included more diverse industries. The results of this study suggest that mission and vision sharing and communication activation system are needed to improve organizational effectiveness of irregular workers.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.249-262
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• 2021

It is believed that there will be changes in the behavior of members according to the characteristics of the organization's leader. The purpose of this study is to find out the factors that induce changes in the behavior of employees of the organization through empirical research. In order to accomplish the research aims, we developed and verify the research model using authentic leadership as an independent variable and the innovative behavior as a criterion variable. In addition, by using the silent phenomenon of the members as a mediating variable, we also tried to find out how it affects the behavior of the employees. Empirical results of the study showed that authentic leadership as an independent variable had a direct influence on the innovation behavior of employees, and the mediating effect of silence also had a partial mediating effect. These findings suggest that leadership and Silence factors which are internal motivational factors leading to behavior of employees are affected innovative behavior. There are some expectations as follow. Based on this study, it would be an important issue that the study on the necessity of silence management of employees through research on the causes of silence felt by members of the organization and the influence.

• Korean Journal of Veterinary Research
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• v.60 no.4
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• pp.215-223
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• 2020

Sasa (S.) quelpaertensis Nakai (Korean name, Jeju-Joritdae), which has anti-oxidative and anti-inflammatory activities, is a type of bamboo grass distributed widely in Jeju Island, Korea. S. quelpaertensis leaves are used for therapeutic purposes in traditional Korean medicine. This study examined the hepatoprotective effects of the S. quelpaertensis ethyl acetate fraction (SQEA) in a mouse model to mimic alcoholic liver damage. The mice were administered orally with 30% alcohol (5 g/kg) once per day with or without SQEA treatments (100 and 200 mg/kg) for 14 days consecutively. Alcohol consumption increased the serum alcohol content and histopathological changes but reduced the liver weight. Moreover, the livers of the alcohol group exhibited the accumulation of malondialdehyde and cytochrome P450 2E1 (CYP2E1), and lipid droplet coating protein perilipin-2. On the other hand, SQEA dose-dependently attenuated the alcohol-induced serum ethanol content and liver histopathological changes but increased the liver weight. Moreover, SQEA attenuated the level of CYP2E1 and inhibited alcohol-induced lipogenesis in the liver via decreased perilipin-2 expression. These results suggest that SQEA can provide a potent way to reduce the liver damage caused by alcohol consumption.

• Knowledge Management Research
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• v.21 no.4
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• pp.287-300
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• 2020

We investigate empirically the impact of IT exploration & exploitation capability and operational capability upon organizational agility, especially small and medium sized firms in the logistics industry in South Korea. Based on literature on the bilateral relationship between organizational agility and IT capability, we follow the established research model and propose hypotheses. This work takes an empirical methodology to test the hypotheses: design survey questionnaires, collect data, test reliability and validity of data, and finally test the hypotheses. Our results based on the data collected in 2018 present that IT exploration & exploitation capability significantly increases operational capability, and operational capability increases organizational agility. We find our contribution in updating previous research findings with recent data and in expanding the domain of research more specifically into small and medium sized firms in logistics industry in South Korea. Practically our work suggests that managers and policy makers should consider both fostering newly emerging IT exploration and existing IT resource exploitation capability in order to enhance organizational agility of those small and medium sized firms in logistics industry.