• Journal of Korean Society of Rural Planning
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• v.15 no.1
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• pp.47-59
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• 2009

The aim of this study is to analyze the green-tourism centrality considering spatial interaction using Gravity Model and social network method. The degree centrality and prestige centrality were applied as green-tourism centrality index. The rural amenity resources and human resources were counted as attraction factors, and a distance among villages was used as friction factor in gravity model. The weights of rural tourism amenity resources were calculated using the analytic hierarchy process(AHP) method and applied to evaluate green-tourism potentiality. The distance was measured with the shortest path among villages using geographic information system(GIS) network analysis. The spatial interaction from gravity model were employed as link weights between nodal points; a pair villages. Using the spatial interaction, the degree-centrality and prestige-centrality indices were calculated by social network analysis and demonstrated possibility of developing integrated green-tourism region centered on high centrality villages.

• Journal of the Korean Geophysical Society
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• v.7 no.4
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• pp.283-291
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• 2004

To find out the locus of the Quinling-Dabie-Sulu continental collision’s boundary and to estimate underground structure of the sedimentray basin in the Yellow Sea, three dimensional density modelling is carrid out by using gravity dataset (Free Air Anomaly), which is measured by Tamhae 2, KIGAM in a period between 2000 and 2002. The measured gravity anomaly in the investigations area is mainly responsed by depth and density differences between the sedimentary basin and the basement. The high density model-bodies extend mainly from the southern part of China to the middle-western part of the Korean Peninsula, which might be emplaced along the continental collision’s boundary. The total volume of the very low density model-bodies might be expected at about 20,000 km3 in the model area.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.11
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• pp.145-155
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• 2021

This study examines the export competitiveness of four major natural rubber exporters in the Belt and Road Initiative (BRI) region and investigates the factors affecting bilateral natural rubber export. This study utilized the revealed symmetric comparative advantage (RSCA) to measure export competitiveness. Next, this study employed the gravity model using the Poisson Pseudo Maximum Likelihood (PPML) estimation to analyze the factors affecting bilateral export from the four major natural rubber exporters to 46 countries in the region. The analysis is conducted by using annual data from 2001 till 2018. The findings showed that all four major exporters maintained their export competitiveness. Indonesia and Vietnam notably exhibited increasing trends in the early 2000s. Besides, the market share for Malaysia and Vietnam have increased from 2013 to 2015 with the BRI implementation in 2013. In addition, this study discovered that non-tariff measures (NTM) have a positive and significant impact on the bilateral export of natural rubber. The overall findings strongly indicate that the natural rubber export has increased post BRI announcement. The outcome highlighted the benefits of BRI implementation on the natural rubber export. This study is the first attempt to apply the gravity model on the natural rubber exports within the BRI region.

• The Journal of Fisheries Business Administration
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• v.51 no.4
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• pp.85-96
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• 2020

The purpose of this study is to find out the determinants of export in Korean fishery products. For the analysis, laver and tuna, which account for almost half of seafood exports, were selected, and a gravity model widely used in trade analysis was applied. As explanatory variables, GDP, number of overseas Koreans, exchange rate, FTA, and WTO were applied, and fixed effect terms were included to take into account multilateral resistance that hinders trade. The analysis period is from 2000 to 2018, and the Poisson Pseudo Maximum Likelihood (PPML) method was applied to solve the problem of zero observation and heteroscedasticity inherent in trade data. As a result of the analysis, GDP was found to have a significant positive effect on both laver and tuna. The number of overseas Koreans was significant in canned tuna exports, but not in laver and the other tuna products. As the exchange rate increased, the export of laver and tuna for sashimi increased. The impacts of the FTA were confirmed in the exports of dried laver and raw tuna, which supports the results of the previous study. WTO was not significant for laver and tuna. Based on these results, it is necessary to find a way to make good use of the FTA to expand exports of seafood.

• East Asian Economic Review
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• v.25 no.1
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• pp.33-71
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• 2021

Many different approaches and databases have been developed for the evaluation of non-tariff measures (NTMs) and free trade agreements (FTAs). This paper is devoted to the EU-South Korea agreement, which is the first 'second-generation' FTA of the EU, addressing a wide array of non-tariff policies. We review the evolution of NTM types applicable to the EU-South Korea trade relationship and the role of NTMs in ex-ante and ex-post analyses of the agreement. Subsequently a structural gravity model is employed to assess the value added of information on different aspects of FTAs and types of NTMs by evaluating their ability to predict the trade effects of the EU-South Korea FTA. Our results show that, when accounting for information on the components common in modern deep trade agreements, no additional trade effect is attributable to the EU-South Korea FTA. The evolution of NTMs differs considerably across indicators used, but trade predictions are hardly affected. Most specifications point towards a negative effect of bilateral differences in the number of technical barriers to trade (TBT) applied and sanitary and phytosanitary measures (SPS) against which trading partners issued complaints at the WTO.

• Computers and Concrete
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• v.31 no.1
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• pp.23-32
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• 2023

Reinforced concrete flat slab (RCFS) with columns is a standard gravity floor system for tall buildings in North America. Typically, RCFS-column connections are designed to resist gravity loads, and their contribution to resisting seismic forces is ignored. However, past experimental research has shown that RCFS-column connections have some strength and ductility, which may not be ignored. Advanced numerical models have been developed in the past to determine the nonlinear cyclic behavior of RCFS-column connections. However, these models are either too complicated for nonlinear dynamic analysis of an entire building or not developed to model the behavior of modern RCFS-column connections. This paper proposes a new nonlinear model suitable for modern RCFS-column connections. The numerical model is verified using experimental data of specimens with various material and reinforcement properties. A 40-story RC shear wall building was designed and analyzed to investigate the influence of RCFS on the global response of tall concrete buildings. The seismic responses of the building with and without the RCFS were modelled and compared. The results show that the modelling of RCFS has a significant impact on the inter-story drifts and force demands on both the seismic force-resisting and gravity elements.

• Asian Journal of Business Environment
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• v.13 no.1
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• pp.31-41
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• 2023

Purpose: This study purposes to analyze the determinants of the volume of Indonesian tuna exports. Research design, data and methodology: The framework was developed from the gravity model for trade, which was expanded with additional variables of competitiveness, exchange rate, and industrial share of the destination country. The data sources used in this study are UN Comtrade and the World Bank. The data used is yearly data from 12 countries in 2001-2019. The scope of the study is limited to exports to the twelve main export destinations. Panel data regression analysis is used to determine the factors that affect the volume of Indonesian tuna exports. Results: The results show that according to the theory, Indonesia's GDP has a positive effect and economic distance has a negative effect on the volume of the exports. Meanwhile, the GDPs of the destination countries are not proven to have a positive effect. However, the higher the industrial share in the country, the higher the export volume tends to be. Conclusions: The conclusion obtained from this study is that Indonesia's GDP, economic distance, real exchange rate, industrial GDP share of the destination country, and the RCA index affect the volume of Indonesian tuna exports.

• Journal of Ocean Engineering and Technology
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• v.16 no.5
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• pp.15-20
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• 2002

In this research, the finite difference lattice Boltzmann method(FDLBM) is used to analyze gravity currents in the lock exchange configuration that occur in many natural and man-made situations. At a lock those are seen when a gate is suddenly opened, and, in the atmosphere, when the thunderstorm outflows make a cold front. At estuaries in the ocean, the phenomenon is found between fresh water from a river and salt water in the sea. Since such interesting phenomena were recognized, pioneers have challenged to make them clear by conducing both experiments and analysis. Most of them were about the currents of liquid or Boussinesq fluids, which are assumed as incompressible. Otherwise, the difference in density of two fluids is small. The finite difference lattice Boltzmann method has been a powerful tool to simulate the flow of compressible fluids. Also, numerical predictions using FDLBM to clarify the gravity currents of compressible fluids exhibit all features, but typically observed in experimental flows near the gravity current head, including the lobe-and-cleft structure at the leading edge.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.115-121
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• 2005

Using a general Saccharomyces cerevisiae as a model strain, continuous ethanol fermentation was carried out in a stirred tank bioreactor with a working volume of 1,500 mL. Three different gravity media containing glucose of 120, 200 and 280 g/L, respectively, supplemented with 5 g/L yeast extract and 3 g/L peptone, were fed into the fermentor at different dilution rates. Although complete steady states developed for low gravity medium containing 120 g/L glucose, quasi-steady states and oscillations of the fermented parameters, including residual glucose, ethanol and biomass were observed when high gravity medium containing 200 g/L glucose and very high gravity medium containing 280 g/L glucose were fed at the designated dilution rate of $0.027\;h^{-1}$. The observed quasi-steady states that incorporated these steady states, quasi-steady states and oscillations were proposed as these oscillations were of relatively short periods of time and their averages fluctuated up and down almost symmetrically. The continuous kinetic models that combined both the substrate and product inhibitions were developed and correlated for these observed quasi-steady states.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.40.4-41
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• 2018

The current 'standard model' of cosmology provides a minimal theoretical framework that can explain the gaussian, nearly scale-invariant density perturbations observed in the CMB to the late time clustering of galaxies. However accepting this framework, requires that we include within our cosmic inventory a vacuum energy that is ~122 orders of magnitude lower than Quantum Mechanical predictions, or alternatively a new scalar field (dark energy) that has negative pressure. An alternative approach to adding extra components to the Universe would be to modify the equations of Gravity. Although GR is supported by many current observations there are still alternative models that can be considered. Recently there have been many works attempting to test for modified gravity using the large scale clustering of galaxies, ISW, cluster abundance, RSD, 21cm observations, and weak lensing. In this work, we compare various modified gravity models using cosmic shear data from the Deep Lens Survey as well as data from CMB, SNe Ia, and BAO. We use the Bayesian Evidence to quantify the comparison robustly, which naturally penalizes complex models with weak data support. In this talk we present our methodology and preliminary results that show f(R) gravity is mildly disfavoured by the data.