This study aimed to analyze causality of climatic factors that affecting the yield of whole crop barley (WCB) by constructing a network within the natural ecosystem via the structural equation model. The WCB dataset (n=316) consisted of data on the forage information and climatic information. The forage information was collected from numerous experimental reports from New Cultivars of Winter Crops (1993-2012) and included details of fresh and dry matter yield, and the year and location of cultivation. The climatic information included details of the daily mean temperature, precipitation, and sunshine duration from the weather information system of the Korea Meteorological Administration. The variables were growing days, accumulated temperature, precipitation, and sunshine duration in the season for the period of seeding to harvesting. The data was collected over 3 consecutive seasons—autumn, winter, and the following spring. We created a causality network depicting the effect of climatic factors on production by structural equation modeling. The results highlight: (i) the differences in the longitudinal effects between autumn and next spring, (ii) the factors that directly affect WCB production, and (iii) the indirect effects by certain factors, via two or more paths. For instance, the indirect effect of precipitation on WCB production in the following spring season via its effect on temperature was remarkable. Based on absolute values, the importance of WCB production in decreasing order was: the following spring temperature (0.45), autumn temperature (0.35), wintering (-0.16), and following spring precipitation (0.04). Therefore, we conclude that other climatic factors indirectly affect production through the final pathway, temperature and growing days in the next spring, in the climate-production network for WCB including temperature, growing days, precipitation and sunshine duration.

The purpose of this study is to identify the leading price between Jeju and Wando’s oliver flounder producer price and to analyze the dynamic effect of the regional producer price using the panel VAR model. In the process of analysis, it was confirmed that there are unit roots in the monthly data of Jeju and Wando’s oliver flounder producer price. So, in order to avoid spurious regression, the rate change of producer price which carries out log difference was used in the analysis. As a result of the analysis, first, the panel Granger causality test showed that the influence of the change rate of producer price in oliver flounder in Jeju was slightly larger than that in Wando, but it was found that each region all leads the change rate of the producer price in oliver flounder. Second, the panel VAR estimation showed that the rate change of producer price in Jeju and Wando a month ago had a statistically significant effect on the change rate of producer price of each region. Third, the impulse response analysis indicated that other regions are affected a little more than the same region in case of the occurrence of the impact on the error terms of the change rate of produce price in Jeju and Wando oliver flounder. Fourth, the variance decomposition analysis showed that the change rate of producer price in the two regions was higher explained by Jeju compared to Wando. In conclusion, it is expected that the above results can not only be useful as basic data for the stabilization of oliver flounder producer price and the establishment of policies for easing volatility but can also help the oliver flounder industry operate its business.

Market integration and prices in pulse crops like black gram play an important role in determining the production decisions of the farmers and diversification towards high value nutritious crops. In this context, the present study explores extent of market integration and price transmission in selected major black gram markets in Andhra Pradesh using Johansen co-integration, Vector Error Correction Model and Granger causality test. The study used monthly prices data of black gram (Rs/quintal) sourced from selected markets of Srikakulam, Krishna and Kurnool spanning January, 1990 to December, 2019. The results of the study strongly buttressed the existence of co-integration and interdependence of selected black gram markets in Andhra Pradesh. However, the speed of adjustment of the prices found to be moderate in Krishna market and quite weaker in Srikakulam market and thereby prices correct a small percentage of the disequilibrium in these markets with the greatest percentage by the external and internal forces. So, it necessitates the need for future research, to investigate the influence of external and internal factors such as market infrastructure, Government policy and self-sufficient production, product characteristics and utilization towards market integration. As there exists only unidirectional causality from Krishna to Kurnool and from Krishna to Srikakulam markets, it calls for strengthening the information technology for flow of market information regularly to help the farmers for increasing their income.

The aim of this study is to analyze the relationship between international oil price as a fuel cost in overseas fisheries and skipjack tuna price as a part of main products in overseas fisheries using monthly time series data from 2008 to 2017. The study also tried to analyze the change of fishing profits by fuel cost. For a time series analysis, this study conducted both the unit-root test for stability of data and the Johansen cointegration test for long-term equilibrium relations among variables. In addition, it used not only the Granger causality test to examine interactions among variables, but also the Vector Auto Regressive (VAR) model to estimate statistical impacts among variables used in the model. Results of this study are as follows. First, each data on variables was not found to be stationary from the ADF unit-root test and long-term equilibrium relations among variables were not found from a Johansen cointegration test. Second, the Granger causality test showed that the international oil prices would directly cause changes in skipjack tuna prices. Third, the VAR model indicated that the posterior t-2 period change of international oil price would have an statistically significant effect on changes of skipjack tuna prices. Finally, fishing profits from skipjack would be decreased by 0.06% if the fuel cost increases by 1%.

This study highlights the theme of safety leadership in railway organization, conducting empirical analysis on the relationship between safety climates, safety leadership, safety behavior, and accident. The empirical test results based on questionnaires received from 223 train drivers working at A subway firm indicated that relationship between CEO's safety philosophy, and safety communication showed a significant positive effect on boss's safety leadership. And boss's safety leadership showed a positive influence on observation belonging to safety behavior, which in turn showed a significant negative relationship with mistake. However, mistake, observation and violation were shown that there are no relationship with accidents.

본 연구는 R&D 투자와 기술무역 변수들 간에 어떠한 인과관계가 있는지를 검 토하고, 그 결과에 대한 정책적 함의를 제시함으로써 연구개발 활동의 촉진과 기술무역 활성 화 방안을 모색하는데 그 목적이 있다. 이에 정부 R&D 투자, 민간 R&D 투자, 기술도입, 그 리고 기술수출로 구성된 다변량 모형을 설정하고, 오차수정모형을 토대로 Granger-인과성 검정을 실시하였다. 분석결과 단기적으로는 총 5개의 인과관계가 성립하는 것으로 나타났고, 장기적으로는 정부 R&D 투자에서 기술수출로의 인과관계를 제외한 11개의 관계에서 인과 성이 존재하는 것으로 확인되었다. 아울러 충격반응분석을 통해 시간의 흐름에 따라 각 변수 들이 특정변수의 충격에 어떻게 반응하는지도 살펴보았다. 본 연구는 R&D 투자와 기술무역 간의 인과관계를 실증적으로 분석함으로써 그 관계를 명확히 하고, 도출된 결과들을 토대로 연구개발 활동 및 기술무역진흥을 위한 시사점을 제시하고 있다는 점에서 그 의의가 있다.

The purpose of this study is to assess the effects of outlook project for olive flounder, from the view point of price stabilization, market efficiency, and causality of the prices in different distribution channels. Analytical results show that the volatility of producer price of olive flounder has been significantly mitigated after the implementation of the outlook project. The market efficiency is estimated to be improved after implementing the outlook project although there is an inefficiency on price determination process in some producing regions. The causality test on the producer and wholesale price shows that producing stage leads the wholesale stage in forming the prices. It is found that Jeju leads the flounder price on the size of 500g and 2kg, while Wando leads the price of 1kg size. These estimation result as whole indicate that outlook project for olive flounder has accomplished the intended goals.

This study aims to analyze causalities among Hairtail prices by distribution channel using a vector autoregressive model. This study applies unit-root test for stability of data, uses Granger causality test to know interaction among Hairtail Prices by distribution channel, and employes the vector autoregressive model to estimate statistical impacts among t-2 period variables used in model. Analyzing results of this study are as follows. First, ADF, PP, and KPSS tests show that the change rate of Hairtail price by distribution channel differentiated by logarithm is stable. Second, a Granger causality test presents that the producer price of Hairtail leads the wholesale price and then the wholesale price leads the consumer price. Third, the vector autoregressive model suggests that the change rate of Hairtail producer price of t-2 period variables statistically, significantly impacts change rates of own, wholesale, and consumer prices at current period. Fourth, the impulse response analysis indicates that impulse responses of the structural shocks with a respectively distribution channel of the Hairtail prices are relatively more powerful in own distribution channel than in other distribution channels. Fifth, a forecast error variance decomposition of the Hairtail prices points out that the own price has relatively more powerful influence than other prices.

Colombo noticeably became the most economical gateway to the Indian subcontinent, in terms of cost as well as time. The Colombo Port Expansion Project (CPEP) started commencement with the purpose of accommodating mega ships, under the long-term strategies of making Colombo the hub of South Asia. In this context, the purpose of this study is to investigate the causal relationship between Indian ports’ originated container traffic, and total transshipments of the port of Colombo, and also to identify the nature of the causality between the two variables, evaluating Granger causality test results. It finds unidirectional causality from total transshipments of Colombo to Indian ports’ originated transshipments in the port of Colombo. It suggested that ongoing port expansion projects, opening up for new markets and attracting new shipping lines in the port of Colombo, have generated significant impact on Indian ports’ container traffic, via the port of Colombo. Findings would be valuable for future forecasting of container traffic in Colombo port and the policy-making process in the port as well.

Algal blooming in 4 major rivers introduces substantial impacts to water front activity. Concentrations of algae are increasing at major points along the Geum River. Ecosystem food webs can be affected by algal blooming because blue-green algae release toxic materials. Even though there have been many studies on blue-green algae, its causality to environmental factors has not been completely determined yet. This study analyzed the exclusive correlation between various hydrometeorological, water quality, and hydrologic variables and the cell number of cyanobacteria to understand causality of blue-green algae in the Geum River. A prewhitening process was introduced to remove the autocorrelation structure and periodicity, which is useful to evaluate the effective relationship between two time series.