• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.243-251
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• 2022

In this paper, we propose a phenomenon that analyze the impact of market sentiment on China's real estate market through the perspective of behavioral economics. Previously, real estate market analyzation basically focus on some fundamental principles which include market price, monetary policies and income, etc. However, little research has explored market sentiment and its influence. By using principal components analysis (PCA), this study first creates buyer's sentiment and seller's sentiment to measure the heat of China's real estate market. Different from using traditional estimation method, the vector autoregressive model (VAR) is used to analyze how both sentiments affect real estate return. The overall results show that from unit root test and impulse response analyzation, the impact of seller's sentiment is positive to real estate market while buyer's sentiment is negative. At the same time, the higher seller's sentiment will have different influence on the housing market compared with the higher buyer's sentiment.

• Korea Trade Review
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• v.47 no.4
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• pp.215-231
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• 2022

Analysis and forecasting of the Baltic Capsize Index (BCI) is important for managing an entity's losses and risks from the uncertainty and volatility of the fast-changing maritime transport market in the future. This study conducted volatility transition analysis through the GARCH model, using BCI which is highly related to steel raw materials. As for the data, 2,385 monthly data were used from March 1999 to March 2021. In this study, after basic statistical analysis, unit root and cointegration test, the GARCH, EGARCH, and DCC-GARCH models were used for volatility transition analysis. As the results of GARCH and EGARCH model, we confirmed that all variables had no autocorrelation between the standardized residuals for error terms and the square of residuals, that the variability of all variables at this time was likely to persist in the future, and that the variability of the time-series error term impact according to Iron ore trade (IoT). In addition, through the EGARCH model, the magnitude convenience of all variables except the Iron ore price (IOP) and Capesize bulk fleet (BCF) variables was greater than the positive value (+). As a result of analyzing the DCC-GARCH (1,1) model, partial linear combinations were confirmed over the entire period. Estimating the effect of variability transition on BCF and C5 with statistically significant linear combinations with BCI confirmed that the impact of BCF on BCI was greater than the impact of BCI itself.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.267-267
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.280-280
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.242-250
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• 2019

In this paper, we propose a method to predict the failure of industrial robot using Seq2Seq (Sequence to Sequence) model, which is a model for transforming time series data among Artificial Neural Network models. The proposed method uses the data of the joint current and angular value, which can be measured by the robot itself, without additional sensor for fault diagnosis. After preprocessing the measured data for the model to learn, the Seq2Seq model was trained to convert the current to angle. Abnormal degree for fault diagnosis uses RMSE (Root Mean Squared Error) during unit time between predicted angle and actual angle. The performance evaluation of the proposed method was performed using the test data measured under different conditions of normal and defective condition of the robot. When the Abnormal degree exceed the threshold, it was classified as a fault, and the accuracy of the fault diagnosis was 96.67% from the experiment. The proposed method has the merit that it can perform fault prediction without additional sensor, and it has been confirmed from the experiment that high diagnostic performance and efficiency are available without requiring deep expert knowledge of the robot.

• The Journal of Industrial Distribution & Business
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• v.10 no.2
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• pp.65-75
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• 2019

Purpose - Along with Chinese exchange rate's reform advancement, the issue of exchange rate of RMB has increasingly become the heated focus in the world. In July 2005, China carried out the reform of the exchange rate system, and this behavior has aroused the attention of the world. However, the dispute on whether the theory of purchasing power parity holds or not in China still exists. As such, this paper will attempt to explore whether the purchasing power parity is significant in China. Research design, data, and methodology - The monthly data from July 2005 to December 2017 will be employed to analyze the nominal exchange rate of RMB against the US dollar and the nominal exchange rate of RMB against the euro. Based on these datum, an empirical analysis will be conducted under the unit root test and the cointegration test to exploit the significance of purchasing power parity in China. Results - The findings of this paper reveal that an increase in China's consumer price index will lead to an increase in the RMB exchange rate, which will lead to the depreciation of RMB. Concomitantly, an increase in the consumer price index in the US and Europe will result in a decrease in the RMB exchange rate, which will lead to an appreciation of RMB. In general, in terms of the US, if US consumer price index increases by 1%, China's nominal exchange rate against US dollar will decrease by 0.905%; if China's consumer price index increases by 1%, China's nominal exchange rate against US dollar will increase by 0.648%. In terms of Europe, if Europe consumer price index increases by 1%, China's nominal exchange rate against euro will decrease by 0.277%; If China's consumer price index increases by 1%, China's nominal exchange rate against euro will increase by 0.235%. Conclusions - Generally speaking, the empirical evidences this paper provided show that the purchasing power parity theory has a certain explanatory ability for the decision of RMB exchange rate. As such, the purchasing power parity cannot hold completely, and China's government should continue to deepen the reform of the exchange rate system to improve China's exchange rate market.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.61-82
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• 2010

The purpose of this study is to examine the causuality among export and import trading volume of port of Busan, Kwangyang, Incheon and to induce policy implications. In order to test whether time series data is stationary and the model is fitness or not, we put in operation unit root test, cointegration test. And We apply Granger causality and impulse response and variance decomposition based on VECM. The results indicate that the trading volume of port of Busan is not largely influenced by that of port of Kawangyang and Incheon, but the trading volume of port of Kawangyang and Incheon is largely influenced by other ports including port of Busan. The result suggest that government has to focus on policy that the port of Kawangyang and Incheon can raise its own competitiveness in the world market.

• Journal of Korea Port Economic Association
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• v.23 no.1
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• pp.1-18
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• 2007

The purpose of this study is to examine the effect of exchange rate volatility on Trading Volume of Container of Korea, and to induce policy implication in the contex of GARCH and regression model. In order to test whether time series data is stationary and the model is fitness or not, we put in operation unit root test, cointegration test. And we apply impulse response functions and variance decomposition to the structural model to estimate dynamic short run behavior of variables. The major empirical results of the study show that the increase in exchange rate volatility exerts a significant negative effect on Trading Volume of Container in long run. The results Granger causality based on an error correction model indicate that uni-directional causality between trading volume of container and exchange rate volatility is detected. This study applies impulse response function and variance decompositions to get additional information regarding the Trading Volume of Container to shocks in exchange rate volatility. The results indicate that the impact of exchange rate volatility on Trading Volume of Container is negative and converges on a stable negative equilibrium in short-run. Th exchange rate volatility have a large impact on variance of Trading Volume of Container, the effect of exchange rate volatility is small in very short run but become larger with time. We can infer policy suggestion as follows; we must make a stable policy of exchange rate to get more Trading Volume of Container

• Journal of Energy Engineering
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• v.29 no.1
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• pp.1-12
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• 2020

The rapid climate change is strengthening carbon emissions regulations internationally. Korea is strongly pressed to accept the obligation to reduce greenhouse gases as one of the United Nations Framework Convention on Climate Change. This article analyzed the Granger causalities among environmental regulation, economic growth, electricity consumption, and CO₂ emission in Korea, using unit root test, cointegration test, and vector error correction model. As the results, environmental regulation has shown the bidirectional causalities with electricity consumption and CO₂ emission, while being unilaterally affected by economic growth in the long-run and strong relationship. Economic growth has affected electricity consumption, CO2 emission, and environmental regulation in the long-run, in the complex structure of the unilateral and short-run causality with electricity consumption and the bidirectional causality with CO2 emission. The policy implications will be as follows: ① environmental regulation should induce sustainable growth through encouraging technological innovation relating to CO2 reduction and productivity enhancement. ② Responding to the international CO2 reduction regulation, the synthetic policy initiatives will be considered to make synergy effects among policies relating to economic growth, electricity consumption.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.357-368
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• 2012

The purpose of this study is to empirically examine the impact of enterprise R&D investment on international trade in Korea under the new Normal Era. In order to test whether the time series data of trade variables are stationary or not, we put in operation unit root test and cointegration test. Based on VECM (Vector Error Correction Model), we also apply impulse response functions and variance decomposition to estimate the dynamic effects in the short-run and long-run. The results show that the relationship between enterprise R&D investment and international trade (export and import) exists in the long-run as well as in the short-run. The results of applying impulse response functions and variance decomposition also indicate that the impact of enterprise R&D investment on international trade is positive, and a significant portion of fluctuations in the trade variable is explained by enterprise R&D investment. Therefore, enterprise R&D investment must be continuously increased to improve economic growth with promoting trading competition power in Korea under the new Normal Era.