• Economic and Environmental Geology
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• v.30 no.2
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• pp.105-116
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• 1997

This study is for extent of polluted area by acid mine drainage from the Daeseong coal mine, Keumsan. Black shales of the Changri Formation containing the Daeseong coal mine are geochemically similar to those from the North America as well as Europe. Comparing with geochemical compositions and relative ratios, coal bearing and non-coal bearing soils are similar to the stream sediments influenced and not influnced by the acid mine drainage, respectively. These characteristics suggest that acidification of the soils and of the stream sediments are related to the the coal bearing black shale. Soil waters beneath the coal bearing soil have low pH and high cation contents than those beneath non-coal bearing soil, suggestive of extractions of cations with increasing oxidizations within the soils. Surface waters show that those influenced by the acid mine drainage are low pH, and have high $SO_4{^{2-}}$, $Mg^{2+}$, $Fe^{2+}$, Mn and slightly lower DO, suggesting that heavy pollutions have been progressed in these area. Geochemical comparisons between the polluted surface water and adjacent black shales suggest that pollutions of the surface water are related to the black shales.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.77-88
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• 2021

The stock markets in the BRICS (Brazil, Russia, India, China and South Africa) countries are the leading emerging markets globally. Therefore, it is pertinent to ascertain the critical drivers of stock market development in these economies. The currrent study empirically investigates to identify the linkages between stock market development, key macro-economic factors and institutional factors in the BRICS economies. The study covers the time period from 2000 to 2017. The dependent variable is the country's stock market development and the independent variables consist of six macroeconomic variables and five institutional variables. The study employs a panel cointegration test, Fully Modified OLS (FMOLS), a Pooled Mean Group (PMG) approach and a heterogeneous panel non-causality test.The findings of the study indicate co-integration among the selected variables across the BRICS stock markets. Long-run estimations reveal that five macroeconomic variables and four variables related to institutional quality are positive and statistically significant. Further, short-run causalities between stock market capitalization and selected variables are detected through the test of non-causality in a heterogeneous panel setting. The findings suggest that policymakers in the BRICS countries should enhance robust macroeconomic conditions to support their financial markets and should strengthen the institutional quality drivers to stimulate the pace of stock market development in their countries.

• Electronics and Telecommunications Trends
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• v.38 no.2
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• pp.56-65
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• 2023

The combination between metaverse and non-fungible token (NFT), which opens up new opportunities for the media industry, raised expectations for a new economic system and business model. Of course, last year, various institutions and researchers continuously introduce representative metaverse services and business strategies such as Roblox, Fortnite, and ZEPETO. However, as 2022 progresses, the reaction to the metaverse is tepid than expected. Search volume on Google has been continuously decreasing. Furthermore, skepticism, regarded as one of the special phenomena caused by the coronavirus disease 2019 pandemic, is expanding since December 2021. Nevertheless, analysis or contemplation of a new business model related to the metaverse, which is still ongoing, is essential for those who must prepare for the future. The reason is that even if without being activated now, advanced preparation can help when various problems arise. In this study, we look at the metaverse and NFT biz models and estimate a picture of the future. In other words, the social and economic problems that may arise when the business model is expanded are summarized, and technical and policy measures are derived as solutions.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.217-220
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• 2008

Recently, many studies about a high-strength concrete and composite structures are being progressed to get the more economic and stable result in the construction of structure all over the world. One of those studies is about CFTA(Concrete Filled and Tied Steel Tubular Arch) girder that applies an arch structure and a pre-stressed structure to CFT(Concrete Filled Steel Tubular) Structure which is filled with a concrete and improve the stiffness and strength of the structure by the confinement effect of fillers to maximize the efficiency of structure and economic. In this study, non-linear behavior of CFTA girders filled with a general concrete and the high-strength concrete respectively were analyzed by using ABAQUS 6.5-1 and results were compared.

• Water Engineering Research
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• v.2 no.2
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• pp.103-112
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• 2001

Issues and problems in formulating South Korea's water resources policy are discussed in terms of water quantity and quality. South Korean needs both water conservation and water supply capability for the growing population and economic activities. The government has attempted to build more large-scale dams to store and supply water for residential, farming and industrial uses, but the environmentalists who emphasize conservation and environmental protection oppose the government. The environmentalists are popular among the general public. Water quality has been deteriorating from point- ad non-point sources. urban and farm runoffs are serious pollutants. All want by preserve water quality. There is no dispute on this matter between the government and the environmentalists. Money is hard to come by to preserve water quality. Economic and financial crises and no self-sufficient local governments' revenue structure are pessimistic. Basic survey on water resources, hydrology and hydraulic is badly needed for the future water resources planning.

• Journal of Welding and Joining
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• v.28 no.6
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• pp.45-50
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• 2010

Most of joining processes for machine and steel structure are performed by butt and fillet welding. The mechanical properties and fatigue strength of their welding zone can be effected largely by the differential of generated heat and changes of grain size according to thickness of material and number of passes in welding process. In this study, it was investigated about characteristics of fatigue failure according to thickness of material and number of passes in cruciform fillet weld zone as the basic study for safe and economic design of welding structures. Fracture modes in cruciform fillet weld zone are classified into toe failure and root failure according to non-penetrated depth. It can be accomplished economic design of welding structures considering fatigue strength when the penetrated depth in fillet weld zone is controled properly.

• Journal of Distribution Science
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• v.11 no.4
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• pp.5-11
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• 2013

Purpose - The aim of this work is to study the reorientation that the export industrial sectors in Costa Rica have experienced during the last 20 years. Research design, data, methodology - The study employs the Cluster Analysis with the export data (20 years of cut-off period) from Costa Rica to the U.S-market. To make the predictions, the technique of the time series was used, with official data (from 2001 to 2010) from the U.S. Department of Commerce and the U.S. International Trade Commission. Results - The Cluster Analysis, show how the economic sectors of traditional products exports of Costa Rica have progressively become in exporters of non-traditional products, meanwhile,the time series confirms that this trend will continue, at least during the next five years. Conclusions - The industry of traditional products exports of Costa Rica (dressmaking, vegetables, coffee, mate, species, etc.) will progressively become in exporters of non- traditional products with a high-tech component (i.e., mechanical equipment and devices, electronic devices and medical equipment),as a consequence of the Chinese (Costa Rica's main competitor) economy's presence in the Organization for Economic Co-operation and Development (OCDE). This fact has enabled the potential improvement of Costa Rica's international competitiveness in the U.S. market.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.4
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• pp.185-206
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• 2011

"Does CRM benefit affect repurchase or WOM? What is difference between VIP customers and non-VIP customers on CRM benefit?" is the interesting issue on premium industry such as a hotel business. This study examines how social benefit, psychological benefits, economic benefits and customization benefits affect repurchase and positive WOM in premium hotel. Only three of the four benefits showed significant results in repurchase and positive WOM. Also interactions between customer type and benefits were different in repurchase and WOM. The results figure out that VIP customers depend on psychological benefits and customization benefits on repurchase, whereas VIP customers depend on only social benefit on WOM. This finding suggests that hotels need to develop VIP program and approach differently to increase the repurchase volume or positive WOM effect.

• Economic and Environmental Geology
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• v.24 no.1
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• pp.71-79
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• 1991

Anisotropy of magnetic susceptibility (AMS), directional variation of susceptibility in a sample, indicates the relative magnitude and orientation of preferentially aligned magnetic grains in a rock sample and represents important aspects of rock fabrics. This observation leads to various studies which applied the AMS technique to numerous geological problems, especially sedimentology, petrology, structural geology, and tectonics. Since AMS is, relative to conventional methods of petrofabric measurement, quickly measured, easily interpretated, and providing quantitative data, AMS technique has evolved into a powerful tool for detection of rock fabrics and continues to draw the interest of non-specialists as well as magnetists. This paper represents the theory, techniques, and parameters of the relatively new AMS method for estimating petrofabrics and their various applications.

• Health Policy and Management
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• v.30 no.2
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• pp.139-141
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• 2020

Coronavirus disease 2019 (COVID-19) is currently in progress. Although it is difficult to predict the end of currently increasing COVID-19, it is expected to last for a long time. The COVID-19 is making a lot of changes. Due to physical distancing and living distancing, non-contacts such as wearing facial masks, online lectures, online medical services, telecommuting, and telemarketing are becoming common. In the era of post-COVID-19, online and offline will coexist. Many countries following China's lockdown strategy, which is agreed with the World Health Organization, should be changed to Taiwan's facial mask strategy for reducing the economic problems. The prolonging COVID-19 will add to the economic difficulties, and the US-China confrontation will be difficult to rebound the global economy. COVID-19, such as plaque, smallpox, and Spanish influenza, will be a historical momentum. How to respond to the crisis of COVID-19 and post-COVID-19 will determine the future of the world and Korea.