• Journal of Digital Convergence
• /
• v.17 no.1
• /
• pp.55-62
• /
• 2019

This study analyzed the relationship between housing price, purchase price, Gini coefficient, interest rate, and the employment, considering that the change in housing price was an important factor influencing macroeconomic variables and income inequality. The panel VAR model was constructed considering the panel data, and the Granger causality, Impulse response and Variance dispersion analysis were performed. As a result, when compared to before and after the global financial crisis, it was shown that the rent price had an effect on income inequality, but in the following period, both the rent price and the selling price affected the income inequality. And that it has a large impact on inequality. In addition, the causality between income inequality and employment rate, interest rate, and tax rate was confirmed. Therefore, it is expected that it will be a desirable policy to mitigate income inequality considering the influence of policy variables for economic activation including government real estate policy.

• The Korean Journal of Financial Management
• /
• v.22 no.2
• /
• pp.189-212
• /
• 2005

This study examines the interactions between KTB spot and futures markets using the daily prices from March 4, 2002 to January 31, 2005. We use Granger causality test, impulse Response Analysis and Variance Decomposition through vector autoregressive analysis (VAR). However, considering the long-term relationships between the level variables of KTB spot and futures, we introduced Vector Error Correction Model. The main results are as follows. According to the results of Granger-causality test and impulse response analysis, we find that the yields of KTB forward have a great influence on the change of KTB spot but not vice versa. In terms of volatility analysis, there is no inter-dependence between KTB forward and spot markets. In the variance decomposition analysis we find that the short-term KTB forward has much more impact on the KTB spot market than the long-term KTB forward does. We think these results are meaningful for bond investors who are in charge of capital asset pricing valuation, risk management and international portfolio management.

• Journal of Technology Innovation
• /
• v.24 no.2
• /
• pp.91-113
• /
• 2016

The purpose of this study is to examine the causal relationship among R&D spending and variables of technology trade, and to explore promoting R&D activities and revitalizing technology trade. To analyze the causal relationship, we built a multivariate model that consists of government R&D spending, private R&D spending, technical importation and export of techniques, and employed the Granger-causality test based on an error correction model. The results show that there are five Granger-causality relationship among them in the short run, as well as there are eleven Granger-causality relationship among a total of twelve causal relationship, excluding only a unidirectional causality relationship from the government R&D spending to the export of techniques, in the long run. Besides, we attempted the impulse-response analysis on them to observe the reaction of any dynamic system in response to some external change. The significance of this paper is to make sure the causal relationship between R&D investments and the technology trade by analyzing empirically, and to suggest several implications for promoting the R&D activities and revitalizing the technology trade.

• Korea Trade Review
• /
• v.48 no.3
• /
• pp.69-88
• /
• 2023

This study analyzes the dynamic characteristics of cargo volume (demand), ship fleet (supply), and freight rate (price) of container, dry bulk, and tanker shipping markets by using the VAR and VECM models. This analysis is expected to enhance the statistical understanding of market dynamics, which is perceived by the actual experiences of market participants. The common statistical patterns, which are all shown in the three shipping markets, are as follows: 1) The Granger-causality test reveals that the past increase of fleet variable induces the present decrease of freight rate variable. 2) The impulse-response analysis shows that cargo shock increases the freight rate but fleet shock decreases the freight rate. 3) Among the three cargo, fleet, and freight rate shocks, the freight rate shock is overwhelmingly largest. 4) The comparison of adjR² reveals that the fleet variable is most explained by the endogenous variables, i.e., cargo, fleet, and freight rate in each of shipping markets. 5) The estimation of co-integrating vectors shows that the increase of cargo increases the freight rate but the increase of fleet decreases the freight rate. 6) The estimation of adjustment speed demonstrates that the past-period positive deviation from the long-run equilibrium freight rate induces the decrease of present freight rate.

• Journal of Korean Society of Forest Science
• /
• v.88 no.1
• /
• pp.1-10
• /
• 1999

The dynamic relationships among import prices of roundwood are analyzed using the time series approach. A vector autoregression(VAR) model is estimated for six import prices(New Zealand, Chile, Russia, U.S.A., PNG, and Malaysia). Then Granger's causality test, variance decomposition analysis, and impulse response function analysis are also conducted. The major results are summarized as follows : (1) The prices of New Zealand and Russia are caused by only own lagged prices. (2) The prices of Chile and PNG are effected by New Zealand, the price of PNG is effected by New Zealand and Russia, and the price of U.S.A. is effected by those of Chile and PNG, respectively. (3) An exogenous shock in New Zealand will affect the prices of New Zealand, PNG, U.S.A., Chile, Russia. (4) An exogenous shock in Chile may also affect the prices of Chile, U.S.A., Russia.

• Journal of the Economic Geographical Society of Korea
• /
• v.15 no.4
• /
• pp.585-600
• /
• 2012

The purpose of this study related to the liquidity impact of the housing market variables using vector auto-regressive model(VAR) and empirical analysis is to derive some policy implications. October 2003 until May 2012 using monthly data for liquidity variables mortgage rates, mortgage, financial liquidity, as the composite index and nation, Seoul, Gangnam, Gangbuk, the Apartment sales prices were analyzed. Granger Causality Test Results, mortgage rates and mortgage at a bargain price two regions had a strong causal relationship. Since the impulse response analysis, Geothermal difference there, but housing price housing price itself, the most significant ongoing positive (+) reactions were liquidity-related variables are mortgage loans is large and persistent positive (+), financial liquidity weakly positive (+), mortgage interest rates are negative (-), KOSPI, the negative (-) reacted. Liquidity and housing prices that the rise can be and Gangnam in Gangbuk is greater than the factor that housing investment was confirmed empirically. Government to consider the current economic situation, while maintaining low interest rates and liquidity of the market rather than the real estate industry must ensure that activities can be embedded and local enforcement policies should be differentiated according to the policy will be able to reap significant effect.

• Journal of the Microelectronics and Packaging Society
• /
• v.15 no.4
• /
• pp.87-92
• /
• 2008

The interface microstructure of Sn-3.5Ag/Cu joint was modified by electroplating varying amount of Zn on Cu UBM. As the amount of Zn dissolved in Sn-3.5Ag solder increased with the electroplating Zn thickness, Cu-Sn IMCs such as $Cu_6Sn_5$ and $Cu_3Sn$ were replaced by Zn-containing IMCs such as $Cu_5Zn_8$ and $Ag_5Zn_8$, which increased the drop reliability of solder joints significantly. When the amount of Zn dissolved in solder was about 3.8wt%, drop resistance was best due to the effective suppression of Cu-Sn IMC and voids at the interface.

• Journal of Korea Port Economic Association
• /
• v.32 no.2
• /
• pp.59-71
• /
• 2016

This study empirically examines the dynamic specification of the ship price model based on a vector autoregressive model and data covering from January 2000 to October 2014. Our results are summarized as follows: first, the relationship between ship price and interest rate shows significantly negative and the relationship between ship price and freight rate shows positive. It provides consistent implication that ship price depends on interest rate and freight rate under the dynamic Gordon model. Second, we apply an impulse response analysis to ship price and find the responses of the ship price from both factors, interest rate and freight rate, which affect during seven periods approximately. Finally, the results of a variance decomposition indicate that freight rate is more important than interest rate on the ship price.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.42.2-42.2
• /
• 2009

연속주조공정에서 용강의 통로, 산화방지 및 유체 흐름을 용이하게 하는 역할을 하는 다공성 노즐(porous nozzle)은 용강과의 직접적인 접촉으로 인한 화학 반응 및 용강의 침투현상을 방지하기 위해 불활성 가스를 주입하여 청정강을 제조하는데 이용된다. 공정 중 노즐 막힘으로 인한 배압상승과 열충격에 의한 크랙(crack) 발생이 문제되고 있으며 신뢰성 향상 연구가 요구되고 있다. 따라서 본 연구에서는 기공크기와 기공분포가 고온안정성 및 내열충격성에 미치는 영향을 알아보고, 내구성 시험 및 고장분석을 통하여 노즐의 신뢰성 향상 방안을 고찰 하였다. 기공을 제어한 시편을 제조하여 기공분포에 따른 고온안정성을 확인하기 위해 실제 사용 조건인 용강온도($1550^{\circ}C$)와 보다 높은 온도($1700^{\circ}C$)에서 각각 고온 시험을 수행하였다. 열충격을 스트레스 인자로 한 내구성 시험을 수행한 후 고장원인을 분석하였으며 열화정도를 확인하기 위해 열처리 온도에 따른 차압 및 굽힘 강도 변화를 비교하였다. 또한 결정상 분석을 통해 온도에 대한 상변화를 확인하였고, 시편의 표면 및 파단면의 미세구조 분석을 통해 크랙 발생여부를 확인하였다. 다공성 노즐의 기공분포가 균일 할수록 고온안정성 및 내열충격성이 향상됨을 확인하였고, 이를 통해 Porous Nozzle의 열화원인으로 판단되는 기공 크기 및 분포에 따른 크랙 발생에 대해 열응력 고찰을 수행하였다.

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