• Journal of Internet Computing and Services
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• v.22 no.5
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• pp.79-86
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• 2021

As the usefulness of big data analysis has been drawing attention, many studies in the business research area begin to use big data to predict firm performance. Previous studies mainly rely on data outside of the firm through news articles and social media platforms. The voices within the firm in the form of employee satisfaction or evaluation of the strength and weakness of the firm can potentially affect firm value. However, there is insufficient evidence that online employee reviews are valid to predict firm value because the data is relatively difficult to obtain. To fill this gap, from 2014 to 2019, we employed 97,216 reviews collected by JobPlanet, an online firm review website in Korea, and developed a machine learning-based predictive model. Among the proposed models, the LSTM-based model showed the highest accuracy at 73.2%, and the MAE showed the lowest error at 0.359. We expect that this study can be a useful case in the field of firm value prediction on domestic companies.

• Journal of Biosystems Engineering
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• v.22 no.3
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• pp.279-288
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• 1997

This study was worked out to obtain fundamental data needed for developing a continuous type dryer. The drying process in a cross-flow type continuous dryer was expressed as partial differential equations, and a drying simulation model for predicting rice moisture content, rice temperature, drying air absolute humidity, drying air temperature was developed by using the finite difference method. To validate the performance of the drying simulation model, a prototype continuous dryer was constructed in this study. The size of the test dryer was one-tenth to that of a commercial continuous dryer. The difference in the outlet rice moisture content between the predicted values and the measured values was within 0.5%, that of outlet rice temperature was below $3^{\circ}C$, that of drying air temperature in drying bed was within $8^{\circ}C$ and that of relative humidity of outlet drying air was big because of the different measuring point. In addition, a drying simulation model for a actual size continuous dryer with double flow was developed in this study. This drying simulation model included the rice mixing effect in the middle of drying length. The difference of outlet moisture content between the predicted and the measured values showed below 0.5% in this study.

• Journal of The Korean Astronomical Society
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• v.37 no.1
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• pp.55-59
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• 2004

We have developed a two fluid solar wind model from the Sun to 1 AU. Its basic equations are mass, momentum and energy conservations. In these equations, we include a wave mechanism of heating the corona and accelerating the wind. The two fluid model takes into account the power spectrum of Alfvenic wave fluctuation. Model computations have been made to fit observational constraints such as electron($T_e$) and proton($T_p$) temperatures and solar wind speed(V) at 1 AU. As a result, we obtained physical quantities of solar wind as follows: $T_e$ is $7.4{\times}10^5$ K and density(n) is $1.7 {\times}10^7\;cm^{-3}$ in the corona. At 1 AU $T_e$ is $2.1 {\times} 10^5$ K and n is $0.3 cm^{-3}$, and V is $511 km\;s^{-1}$. Our model well explains the heating of protons in the corona and the acceleration of the solar wind.

• Korean journal of communication and information
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• v.37
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• pp.418-451
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• 2007

The current study examined the relationships between the adolescent's conflict resolution style and Big-Five personality factors, self-monitoring and self-esteem. Firstly, results showed that adolescent's big-five personality model affects their conflict resolution styles with their friends and peer group. In detail, the higher the neuroticism was, the stronger became the attack and avoidance strategies. The higher the extraversion was, the higher became the collaborative strategy and the lower became the attack and avoidance strategies. The higher the agreeableness was, the higher became the collaborative strategy and the lower became the attack strategy. The higher the conscientiousness was, the higher became the collaborative strategy and the lower became the avoidance strategy. The higher the openness to experience was, the higher became the collaborative strategy and the lower became the avoidance strategy. The higher the self-esteem was, the higher became the collaborative strategy and the lower became the avoidance and attack strategies. The higher the self-monitoring was, the higher became the collaborative strategy and the lower became the avoidance strategy. Secondly, the big-five personality factors also affected the adolescent's conflict resolution styles. The extraversion, conscientiousness, and agreeableness positively affected the collaborative strategy. The neuroticism was positively related with the attack strategy, whereas agreeableness was negatively affected the attack strategy. The neuroticism and agreeableness were positively related with the avoidance strategy, whereas the extraversion was negatively affected the avoidance strategy. Limitations and suggestions for future study were discussed thereafter.

• Journal of Engineering Education Research
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• v.19 no.5
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• pp.57-64
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• 2016

This study is about interdisciplinary education model of using Davis Guggenheim's documentary film on global warming which is a big concern in climate change issues, An Inconvenient Truth. It based on Al Gore's slide speech. Through a course student analyzed the cause and phenomenon of global warming resulted from increase of $CO_2$ by using fossil fuel and its environmental science effects-heat wave, desertification, tornado, hurricane, sea level rise caused by melting glaciers, destroying ecosystem like habitat degradation of wild animals, for example polar bear, extreme cold wave caused by change of ocean currents- of global warming. After, student discussed of efforts to prevent global warming. This educational model is appropriate for lower grade student of environmental engineering and also available for converged majors or general education class.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.129-140
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• 2015

The objective of this study is mainly to examine factors affecting utilization of graphical emoticons in the environment of mobile messenger. For this purpose, this research identified several determinants including demographic variables that have influences on utilization of graphical emoticons by an overview of prior research on Big 5 model and Uses and Gratification (U & G). An online survey was employed to collect data, and hierarchical regression analysis was used for data analysis. The results showed that females and younger respondents have higher utilization of graphical emoticons than males and the older. The findings also showed that extraversion as personal traits has influences on the utilization. And they indicated that people increase their utilization of graphical emoticons when they want to communicate with others efficiently and succinctly, and to follow the trend. The practical and theoretical implications of the findings in this study are also discussed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.265-272
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• 2019

In this study, we conducted a prediction study to qualitatively identify the continuous growth rate that causes problems every year for deposit bank mortgage loans, identify the characteristic factors that could once again stabilize, and come up with measures for future quantitative analysis of mortgage loans and growth trends. Based on data analysis using the R program, which is widely used for big data analysis, the parameters of ARIMA model (0.1,1)(0.1,1)[12] were found to be most suitable. In these indicators, estimates over the next five years (60 months) increased 4.5% on average. However, this has limitations that do not reflect socio-environmental factors, which require further study of these limitations.

• Journal of Internet Computing and Services
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• v.5 no.5
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• pp.61-68
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• 2004

In this paper, a more accurate model than any other ones so far have been proposed for the performance evaluation of muntibuffered banyan-type Multistage Interconnection Networks(MINs)'s under nonuniform traffic condition is obtained. Small clock cycle instead of big clock cycle is used to improve the performance. The accuracy of the proposed model is conformed by comparing with the results from simulation.

• Journal of Navigation and Port Research
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• v.42 no.5
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• pp.341-346
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• 2018

Supramax bulk carriers cover a wide range of ocean transportation requirements, from major to minor bulk cargoes. Market forecasting for this segment has posed a challenge to researchers, due to complexity involved, on the demand side of the forecasting model. This paper addresses this issue by using technical indicators as input features, instead of complicated supply-demand variables. Artificial neural networks (ANN), one of the most popular machine-learning tools, were used to replace classical time-series models. Results revealed that ANN outperformed the benchmark binomial logistic regression model, and predicted direction of the spot market with more than 70% accuracy. Results obtained in this paper, can enable chartering desks to make better short-term chartering decisions.

• Journal of Multimedia Information System
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• v.5 no.2
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• pp.111-114
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• 2018

Traffic accident analysis is important to reduce the occurrence of the accidents. In this paper, we analyze the traffic accident with Apriori algorithm to find out an association rule of traffic accident in Korea. We first design the traffic accident analysis model, and then collect the traffic accidents data. We preprocessed the collected data and derived some new variables and attributes for analyzing. Next, we analyze based on statistical method and Apriori algorithm. The result shows that many large-scale accident has occurred by vans in daytime. Medium-scale accident has occurred more in day than nighttime, and by cars more than vans. Small-scale accident has occurred more in night time than day time, however, the numbers were similar. Also, car-human accident is more occurred than car-car accident in small-scale accident.