• Economic and Environmental Geology
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• v.26 no.4
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• pp.433-444
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• 1993

Electrum (32~73 atom. % Ag)-sulfide mineralization of the Bodeok mine in the Boseong area was deposited in two stages of mineralogically simple, massive quartz veins that fill the fractures along fault shear zones in Precambrian gneiss. Radiometric dating indicates that mineralization is Late Jurassic age ($155.9{\pm}2.3$ Ma). Fluid inclusion data show that ore mineralization was formed from $H_2O-CO_2$ fluids with variable $CO_2$ contents ($X_{CO_2}=0.0$ to 0.7) and low salinities (0.0 to 7.4 wt. % eq. NaCl) at temperatures between $200^{\circ}$ and $370^{\circ}C$. Evidence of fluid unmixing ($CO_2$ effervescence) indicates pressures up to 1 kbar. Gold-silver deposition occurred later than base-metal sulfide deposition, at temperatures near $250^{\circ}C$ and was probably a result of cooling and decreasing sulfur activity caused by sulfide precipitation and/or $H_2S$ loss (through fluid unmixing). Calculated sulfur isotope compositions of ore fluids (${\delta}^{34}S_{{\Sigma}S}=1.7$ to 3.3‰) indicate an igneous source of sulfur in hydrothermal fluids. Measured and calculated O and H isotope compositions of ore fluids (${\delta}^{18}O_{water}=4.8$ to 7.2‰, ${\delta}D_{water}=-73$ to -76‰) indicate that mesothermal auriferous fluids at Bodeok were likely mixtures of $H_2O-rich$, isotopically evolved meteoric waters and magmatic $H_2O-CO_2$ fluids.

• KDI Journal of Economic Policy
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• v.12 no.2
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• pp.135-149
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• 1990

Housing owners in Korea have a variety of tax advantages such as income tax exemption for the imputed rent of owner-occupied housing, exemption from the capital gains tax and deduction of the estate tax for one-house households. These tax reliefs for housing owners not only conflict with the principle of horizontal and vertical equity, but also lead to resource misallocation by distorting the housing market, and thus bring about regressive distribution effects. Particularly in the case of Korea with its imperfect capital market, these measures exacerbate the inter-class inequality of housing ownership as well as inequalities in wealth, by causing the affluent to demand needlessly large housing, while the poor and young experience difficulties in purchasing residential properties. Therefore, the Korean tax system must be altered as follows in order to disadvantage owner-occupiers, especially those owners of luxury housing. These alterations will promote housing-ownership, tax burden equity, efficiency of resource allocation, as well as the desirable distribution of income. First, income tax deductions for the rent payments of tenants are recommended. Ideally, the way of recovering the fiscal equivalence between the owner-occupiers and tenants is to levy an income tax on the former's imputed rents, and if necessary to give them tax credits. This, however, would be very difficult from a practical viewpoint, because the general public may perceive the concept of "imputed rent" as cumbersome. Computing the imputed rent also entails administrative costs, rendering quite reasonable, the continued exemption of imputed rent from taxation with the simultaneous deduction in the income tax for tenants. This would further enhance the administrative efficiency of income tax collection by easing assessment of the landlord's income. Second, a capital gains tax should be levied on the one-house household, except with the postponement of payments in the case that the seller purchases higher priced property. Exemption of the capital gains tax for the one-house household favors those who have more expensive housing, providing an incentive to the rich to hold even larger residences, and to the constructors to build more luxurious housing to meet the demand. So it is not desirable to sustain the current one-house household exemption while merely supplementing it with fastidious measures. Rather, the rule must be abolished completely with the concurrent reform of the deduction system and lowering of the tax rate, measures which the author believes will help optimize the capital gains tax incidence. Finally, discontinuation of the housing exemption for the heir is suggested. Consequent increases in the tax burden of the middle class could be mitigated by a reduction in the rate. This applies to the following specific exemptions as well, namely, for farm lands, meadows, woods, business fields-to foster horizontal equity, while denying speculation on land that leads to a loss in allocative efficiency. Moreover, imperfections in the Korean capital market have disallowed the provision of long term credit for housing seekers. Remedying these problems is essential to the promotion of greater housing ownership by the low and middle income classes. It is also certain that a government subsidy be focused on the poorest of the poor who cannot afford even to think of owning a housing.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.557-561
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• 1994

Q estimates are made by direct measurements of energy loss per cycle from primary P and S waves, as a function of frequency. Assuming that intrinsic Q is frequency independent and scattering Q is frequency dependent over the frequencies of interest, the relative contributions of each, to a total observed Q, may be estimated. Test examples are produced by computing viscoelastic synthetic seismograms using a pseudo spectral solution with inclusion of relaxation mechanisms (for intrinsic Q) and a fractal distribution of scatterers (for scattering Q). The composite theory implies that when the total Q for S-waves is smaller than that for P-waves (the usual situation), intrinsic Q is dominating; when it is larger, scattering Q is dominating. In the inverse problem, performed by a global least squares search, intrinsic $Q_p$ and $Q_s$ estimates are reliable and unique when their absolute values are sufficiently low that their effects are measurable in the data. Large $Q_p$ and $Q_s$ have no measurable effect and hence are not resolvable. Standard deviation of velocity $({\sigma})$ and scatterer size (A) are less unique as they exhibit a tradeoff as predicted by Blair's equation. For the P-waves, intrinsic and scattering contributions are of approximately the same importance, for S-waves, the intrinsic contributions dominate.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.4
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• pp.167-178
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• 2021

The purpose of this study is to analyze the direct investment decision factors in the Kaesong Industrial Complex and Vietnam, and to contribute to the creation of domestic jobs and the revitalization of the inter-Korean economy. According to the analysis, most of the Kaesong Industrial Complex and Vietnamese investment companies are entering the complex for the purpose of utilizing cheap labor, cheap factory locations, sales/development of local markets, and bypass export production bases in third countries. This can be divided into production-efficient investors using differences in production price such as labor costs and market-oriented investors to sell and expand the local market, which seems to be consistent with global direct investment patterns such as Nike, Apple, and Amazon. However, even if the North Korea-U.S. denuclearization talks ease or lift sanctions, Vietnamese investors' willingness to invest in the North Korea has been most burdened by the possibility of closing special economic zones due to political risks. Last but not least, it is important to note that those willing to invest in North Korea are mostly smaller enterprises in textiles, sewing, footwear and leather industries-those that benefit from low-cost labor. Since their size is small, they need policy support in financing, especially in the early stages of their business. Even after they grow past the early stages, those without collateral would still need state guarantee letters to get financing. Thus, it is worth considering to use the Inter-Korean Cooperation Fund to compensate commercial banks for bad loan loss or for low-interest loans for smaller SMEs. The interviews with SMEs found that red-tape is one of the biggest difficulties they face. Thus, it is recommended that a one-stop service agency should be established to cover all processes and issues related to inter-Korean economic cooperation to eliminate redundancy and expediate government support for SMEs.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.17-30
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• 2020

In the shipping industry, it is essential to engage in the preemptive prediction of freight rate volatility through market monitoring. Considering that freight rates have already started to fall, the loss of shipping companies will soon be uncontrollable. Therefore, in this study, factors affecting the freight rates of bulk carriers, which have relatively large freight rate volatility as compared to container freight rates, were quantified and analyzed. In doing so, we intended to contribute to future shipping market monitoring. We performed an analysis using a vector error correction model and estimated the influence of six independent variables on the charter rates of bulk carriers by Handy Size, Supramax, Panamax, and Cape Size. The six independent variables included the bulk carrier fleet volume, iron ore traffic volume, ribo interest rate, bunker oil price, and Euro-Dollar exchange rate. The dependent variables were handy size (32,000 DWT) spot charter rates, Supramax 6 T/C average charter rates, Pana Max (75,000 DWT) spot charter, and Cape Size (170,000 DWT) spot charter. The study examined charter rates by size of bulk carriers, which was different from studies on existing specific types of ships or fares in oil tankers and chemical carriers other than bulk carriers. Findings revealed that influencing factors differed for each ship size. The Libo interest rate had a significant effect on all four ship types, and the iron ore traffic volume had a significant effect on three ship types. The Ribo rate showed a negative (-) relationship with Handy Size, Supramax, Panamax, and Cape Size. Iron ore traffic influenced three types of linearity, except for Panamax. The size of shipping companies differed depending on their characteristics. These findings are expected to contribute to the establishment of a management strategy for shipping companies by analyzing the factors influencing changes in the freight rates of charterers, which have a profound effect on the management performance of shipping companies.

• Journal of Energy Engineering
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• v.28 no.2
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• pp.18-35
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• 2019

The Korea District Heating Corporation operates a gas engine generator with a capacity of $4500m^3 /day$ of biogas generated from the sewage treatment plant of the Nanji Water Recycling Center and 1,500 kW. However, the actual operation experience of the biogas power plant is insufficient, and due to lack of accumulated technology and know-how, frequent breakdown and stoppage of the gas engine causes a lot of economic loss. Therefore, it is necessary to prepare technical fundamental measures for stable operation of the power plant In this study, a series of process problems of the gas engine plant using the biogas generated in the sewage treatment plant of the Nanji Water Recovery Center were identified and the optimization of the actual operation was made by minimizing the problems in each step. In order to purify the gas, which is the main cause of the failure stop, the conditions for establishing the quality standard of the adsorption capacity of the activated carbon were established through the analysis of the components and the adsorption test for the active carbon being used at present. In addition, the system was applied to actual operation by applying standards for replacement cycle of activated carbon to minimize impurities, strengthening measurement period of hydrogen sulfide, localization of activated carbon, and strengthening and improving the operation standards of the plant. As a result, the operating performance of gas engine # 1 was increased by 530% and the operation of the second engine was increased by 250%. In addition, improvement of vent line equipment has reduced work process and increased normal operation time and operation rate. In terms of economic efficiency, it also showed a sales increase of KRW 77,000 / year. By applying the strengthening and improvement measures of operating standards, it is possible to reduce the stoppage of the biogas plant, increase the utilization rate, It is judged to be an operational plan.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.715-728
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• 2023

Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

• KDI Journal of Economic Policy
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• v.12 no.3
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• pp.27-45
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• 1990

Two opposing views prevail regarding the economic impact of rural out-migration on the rural areas of origin. The optimistic neoclassical view argues that rapid rural out-migration is not detrimental to the income and welfare of the rural areas of origin, whereas Lipton (1980) argues the opposite. We developed our own alternative model for rural to urban migration, appropriate for rapidly developing economies such as Korea's. This model, which adopts international trade theories of nontraded goods and Dutch Disease to rural to urban migration issues, argues that rural to urban migration is caused mainly by two factors: first, the unprofitability of farming, and second, the decrease in demand for rural nontraded goods and the increase in demand for urban nontraded goods. The unprofitability of farming is caused by the increase in rural wages, which is induced by increasing urban wages in booming urban manufacturing sectors, and by the fact that the cost increases in farming cannot be shifted to consumers, because farm prices are fixed worldwide and because the income demand elasticity for farm products is very low. The demand for nontraded goods decreases in rural and increases in urban areas because population density and income in urban areas increase sharply, while those in rural areas decrease sharply, due to rapid rural to urban migration. Given that the market structure for nontraded goods-namely, service sectors including educational and health facilities-is mostly in monopolistically competitive, and that the demand for nontraded goods comes only from local sources, the urban service sector enjoys economies of scale, and can thus offer services at cheaper prices and in greater variety, whereas the rural service sector cannot enjoy the advantages offered by scale economies. Our view concerning the economic impact of rural to urban migration on rural areas of origin agrees with Lipton's pessimistic view that rural out-migration is detrimental to the income and welfare of rural areas. However, our reasons for the reduction of rural income are different from those in Lipton's model. Lipton argued that rural income and welfare deteriorate mainly because of a shortage of human capital, younger workers and talent resulting from selective rural out-migration. Instead, we believe that rural income declines, first, because a rapid rural-urban migration creates a further shortage of farm labor supplies and increases rural wages, and thus reduces further the profitability of farming and, second, because a rapid rural-urban migration causes a further decline of the rural service sectors. Empirical tests of our major hypotheses using Korean census data from 1966, 1970, 1975, 1980 and 1985 support our own model much more than the neoclassical or Lipton's models. A kun (county) with a large out-migration had a smaller proportion of younger working aged people in the population, and a smaller proportion of highly educated workers. But the productivity of farm workers, measured in terms of fall crops (rice) purchased by the government per farmer or per hectare of irrigated land, did not decline despite the loss of these youths and of human capital. The kun having had a large out-migration had a larger proportion of the population in the farm sector and a smaller proportion in the service sector. The kun having had a large out-migration also had a lower income measured in terms of the proportion of households receiving welfare payments or the amount of provincial taxes paid per household. The lower incomes of these kuns might explain why the kuns that experienced a large out-migration had difficulty in mechanizing farming. Our policy suggestions based on the tests of the currently prevailing hypotheses are as follows: 1) The main cause of farming difficulties is not a lack of human capital, but the in­crease in production costs due to rural wage increases combined with depressed farm output prices. Therefore, a more effective way of helping farm economies is by increasing farm output prices. However, we are not sure whether an increase in farm output prices is desirable in terms of efficiency. 2) It might be worthwhile to attempt to increase the size of farmland holdings per farm household so that the mechanization of farming can be achieved more easily. 3) A kun with large out-migration suffers a deterioration in income and welfare. Therefore, the government should provide a form of subsidization similar to the adjustment assistance provided for international trade. This assistance should not be related to the level of farm output. Otherwise, there is a possibility that we might encourage farm production which would not be profitable in the absence of subsidies. 4) Government intervention in agricultural research and its dissemination, and large-scale social overhead projects in rural areas, carried out by the Korean government, might be desirable from both efficiency and equity points of view. Government interventions in research are justified because of the problems associated with the appropriation of knowledge, and government actions on large-scale projects are justified because they required collective action.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.25-41
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• 2011

Recently, support vector machines (SVMs) are being recognized as competitive tools as compared with other data mining techniques for solving pattern recognition or classification decision problems. Furthermore, many researches, in particular, have proved them more powerful than traditional artificial neural networks (ANNs) (Amendolia et al., 2003; Huang et al., 2004, Huang et al., 2005; Tay and Cao, 2001; Min and Lee, 2005; Shin et al., 2005; Kim, 2003).The classification decision, such as a binary or multi-class decision problem, used by any classifier, i.e. data mining techniques is so cost-sensitive particularly in financial classification problems such as the credit ratings that if the credit ratings are misclassified, a terrible economic loss for investors or financial decision makers may happen. Therefore, it is necessary to convert the outputs of the classifier into wellcalibrated posterior probabilities-based multiclass credit ratings according to the bankruptcy probabilities. However, SVMs basically do not provide such probabilities. So it required to use any method to create the probabilities (Platt, 1999; Drish, 2001). This paper applied AdaBoost algorithm-based support vector machines (SVMs) into a bankruptcy prediction as a binary classification problem for the IT companies in Korea and then performed the multi-class credit ratings of the companies by making a normal distribution shape of posterior bankruptcy probabilities from the loss functions extracted from the SVMs. Our proposed approach also showed that their methods can minimize the misclassification problems by adjusting the credit grade interval ranges on condition that each credit grade for credit loan borrowers has its own credit risk, i.e. bankruptcy probability.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.26-27
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• 2018

With entry into force of the Nagoya Protocol to promote the fair sharing of the benefits of accessing and utilizing genetic resources, much support has been given to research on the development of biomaterials and products using domestic natural resources. Conservation and resource-saving of native species became very important through Nagoya Protocol enactment. The trend of cosmetic industry has been shifing from use synthetic chemicals to natural biomaterials, due to the safety regulations on new materials, ban on animal experiments, and expansion of cosmeceuticals range. In addition, functional cosmetic range has been expanded from whitening, wrinkle improvement, and ultraviolet shielding, to hair loss, hair loss alleviation, acne relaxation, and moisturizing of atopic skin, thus causing the activation of research about field of efficacy evaluation on natural biomaterials and commercialization. Chungbuk province is fostering the bio industry as a key industry for regional economic growth. For this purpose, Osong Biotechnology Complex/Ochang Science Industrial Complex in middle area, Jecheon biovalley in northern region, and Chungju Enterprise city have been established, thus playing a pivotal role in Bio innovative cluster in Korea. In particular, it was established the osong cosmetics clinical research support center to develop the cosmetics industry in chungbuk, thereby supporting clinical trials, efficacy evaluations, overseas certification, and overseas market entry in order to advance into the global market. In addition, oriental plants such as astragalus propinquus, schisandra chinensis, eucommia, alpiniae oxyphyllae fructus and biancaea sappan are being actively studied as global cosmetic ingredients through the promotion of various national research and development projects using natural materials in chungbuk province. The chungbuk natural product industry is expected to grow further throughout cosmetics industry development in the future, as companies and research institutes are actively promoting the secure index of effective material in natural products and effective material commercialization.