• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.191-212
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• 1992

This paper discusses the role of money in the process of capital accumulation where financial markets are impeded by contract enforcement problems in the context of overlapping generations framework. In particular, in less developed countries (LDCs) creditors may know little about the repayment capability of potential debtors due to incomplete information so that financial instruments other than money may not acceptable to them. In this paper the impediments to the operation of the private finanical markets are explicitly modelled. We argue that creditors cannot observe actual investment decisions made by the potential borrowers, and as a result, loan contracts may not be fully enforceable. Therefore, a laissez-faire regime may fail to provide the economy with the appropriate financial instruments. Under these circumstances, we introduce a government operated discount window (DW) that acts as an open market buyer of private debt. This theoretical structure represents the practice of governments of many LDCs to provide loans (typically at subsidized interest rates) to preferred borrowers either directly or indirectly through the commercial banking system. It is shown that the DW can substantially overcome impediments to trade which are caused by the credit market failure. An appropriate supply of the DW loan enables producers to purchase the resources they cannot obtain through direct transactions in the credit market. This result obtains even if the DW is subject to the same enforcement constraint that is responsible for the market failure. Thus, the DW intervention implies higher investment and output. However, the operation of the DW may cause inflation. Furthermore, the provision of cheap loans through the DW results in a worse income distribution. Therefore, there is room for welfare enhancing schemes that utilize the higher output to develop. We demonstrate that adequate lump sum taxes-cum-transfers along with the operation of the DW can support an allocation that is Pareto superior to the laissez-faire equilibrium allocation.

• KDI Journal of Economic Policy
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• v.14 no.4
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• pp.3-26
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• 1992

The pupose of this paper is to construct a price determination model of the Korean economy and to find out the propogation mechanism of monetary and fiscal policies. The model is a small-size macroeconometric model consisted of ten core equations : consumption, investment, exports, imports, consumer price index, wage rate, corporate bond rate, potential GNP, capital stock, and GNP identity. The model is a Keynesian model : consumer price index is determined by markup over costs, and wage rate is expressed by Phillipse curve ralation. Two features of the model, however, distinguish this model from other macroeconometric models of the Korean economy. First of all, the estimation of potential GNP and the capital stock is endogenized as suggested by Haque, Lahiri, and Montiel (1990). This allows us to calculate the level of excess demand, which is defined as the difference between the actual GNP and the potential GNP. Second, interest rate, inflation and wages are all estimated as endogenous variables. Moreover, all quantity variables include price variables as important determinants. For instance, interest rate is an important determinant of consumption and investment. Exports and imports are determined by the real effective exchange rate. These two features make the interactions between excess demand and prices the driving forces of this model. In the model, any shock which affects quantity variable(s) affects excess demand, which in turn affects prices. This strong interaction between prices and quantities makes the model look like a classical model over the long run. That is, increases in money supply, government expenditures, and exchange rate (the price of the U.S. dollar in terms of Korean won) all have expansionery effects on the real GNP in the short run, but prices, wage, and interest rate all increase as a result. Over the long run, higher prices have dampenning effects on output. Therefore the level of real GNP turns out to be not much different from the baseline level ; on the other hand, the rates of inflation, wage and interest rate remain at higher levels.

• KDI Journal of Economic Policy
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• v.34 no.1
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• pp.87-133
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• 2012

This paper consists of two parts. The first part introduces a simple endogenous growth model. It is based on Romer(1990), but extends the original model by incorporating individual workers skill heterogeneity. Based on the heterogeneity, the model has a labor allocation mechanism between skilled (research) and unskilled (production) sectors. Different from Romer(1990), the labor allocation is determined by both demand and supply conditions of the economy. The endogenous growth model presented in this paper shows how the shape of the distribution of human capital affects on the labor allocation, hence on the employment structure, wage profile and economic growth. The model can be extended to an open economy. With the heterogeneity, the extended model explains distributional effect as well as growth effect of the economic openness. The second part provides empirical evidence in support of the extension part of the model presented in the first part. Based on the endogenous growth framework as proposed by Romer(1990) and Rivera-Batiz and Romer(1991), the model explains how economic openness affects labor allocation between skilled and unskilled sectors. According to the model, economic openness can affect labor allocation through two channels; knowledge spillover and specialization. First, the openness promotes knowledge spillover and hence increases the productivity of workers in the skilled sectors. This makes the economy employs more workers in the skilled sector. On the other hand, the openness causes global specialization which leads more employment in the skilled sector for the developed countries but at the same time, leads less employment in the skilled sector for the developing countries since the developing countries have comparative advantages in the unskilled sector. The empirical results obtained using cross country panel data in this paper support these two effects of knowledge spillover and specialization.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.118-123
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• 2012

In order to develop environment friendly fungicide for the control of citrus green mold (Penicillium digitatum) using endophytic bacteria, the 21 bacterial isolates were isolated from citrus leaves in seven different orchards in Jeju Province. Among the 21 bacterial isolates, 5 bacterial isolates presented antifungal activity against green mold pathogen P. digitatum. The CB3 isolate, which showed the most strong antagonistic effect, was selected through opposite culture against the pathogen. The rod-shaped, gram-positive bacterium CB3 was identified as Bacillus velezensis based on morphological, physiological characteristics, 16S rDNA, and gyr A gene sequence analysis. The isolate CB3 showed strong antifungal activity against two citrus postharvest pathogen P. digitatum. Citrus fruits were treated by wound inoculation with P. digitatum pathogen, and the control efficacy of CB3 culture broth was 66.7% ($1{\times}10^8$ cfu/ml). In conclusion, The stability of CB3 and its strong antifungal activity also lead us to believe that it has potential for application as an environment friendly biological control agent.

• Journal of Mushroom
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• v.18 no.1
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• pp.1-9
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• 2020

Mycorrhiza refers to the association between a plant and a fungus colonizing the cortical tissue of the plant's roots during periods of active plant growth. The benefits afforded by plants from mycorrhizal symbioses can be characterized either agronomically, based on increased growth and yield, or ecologically, based on improved fitness (i.e., reproductive ability). In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil. The soilborne or extramatrical hyphae take up nutrients from the soil solution and transport them to the root. This mycorrhizae-mediated mechanism increases the effective absorptive surface area of the plant. There are seven major types of mycorrhizae along with mycoheterotrophy: endomycorrhizae (arbuscular mycorrhizae, AM), ectomycorrhizae (EM), ectendomycorrhizae, monotropoid, arbutoid, orchid, and ericoid. Endomycorrhizal fungi form arbuscules or highly branched structures within root cortical cells, giving rise to arbuscular mycorrhiza, which may produce extensive extramatrical hyphae and significantly increase phosphorus inflow rates in the plants they colonize. Ectomycorrhizal fungi may produce large quantities of hyphae on the root and in the soil; these hyphae play a role in absorption and translocation of inorganic nutrients and water, and also release nutrients from litter layers by producing enzymes involved in mineralization of organic matters. Over 4,000 fungal species, primarily belonging to Basidiomycotina and to a lesser extent Ascomycotina, are able to form ectomycorrhizae. Many of these fungi produce various mushrooms on the forest floor that are traded at a high price. In this paper, we discuss the benefits, nutrient cycles, and artificial cultivation of mycorrhizae in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.433-437
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• 2006

Recently, mathematical modeling for the activated sludge process is important to design and control of wastewater treatment plant. Nevertheless, there is a lack of information regarding the pathway of substrate utilization between external and internal substrates in biological nutrient removal (BNR). In this research, a new activated sludge model (step growth model) is proposed and compare with ASM No.3. This model structure is consist of five processes; aerobic storage, growth on external substrate and stored intercellular storage compounds (ISCs), endogenous respiration and aerobic respiration of ISCs. The predicted results by the step growth model were more good accordance with the results of oxygen utilization rate (OUR) and TCOD experiment than that of the ASM No.3.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.197-208
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• 2017

The purpose of this study was to construct and test a structural equation model for college student's gambling behavior. A structured questionnaire was completed by 246 college students to analyze the relationships between perspective factors(irrational gambling belief), psychological factors(depression, anxiety), social factors(parental monitoring, parental support, friend support), self-control and gambling behavior. The moderating effects of gender, friends and family's gambling behaviors were examined. The data were analyzed using SPSS 21,0 and AMOS 20.0 programs. Self-control and psychological factors directly affected the college student's gambling behavior, while perspective factors and social factors affected it indirectly. The model fit indices of the modified model were suitable for the recommended levels. The overall study findings suggest the need to develop a gambling prevention program for college students that reinforces self-control, parental monitoring and support, and friend support while reducing irrational gambling belief, depression, and anxiety. An approach that considers gender and a development of a group counseling program for family or friends are also required.

• Journal of Technology Innovation
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• v.21 no.1
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• pp.59-83
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• 2013

Recently, the importance of the health care industry is increasing due to the rapid changes in the population structure caused by decreasing in fertility rate and aging population. Therefore expansion of government investment in R&D of the health care industry is needed as the demand of health care is increasing. This study attempts to examine the economic impacts of national research and development for the health care industry using an inter-industry analysis. Specifically, the study investigates production-inducing effect, value added inducing effect, and employment-inducing effect of the health care industry based on demand-driven model. These analyses pay particular and close attention to the health care industry by taking it as exogenous rather than endogenous. Here we present results. First, the production-inducing effect and value added inducing effect was high in common real estate and business services and finance and insurance sector. Second, employment-inducing effect of the health care industry showed the highest levels in wholesale and retail sector, followed by the real estate and business services, agriculture sector. Third, the actual 2009 health care industry-related national R&D investment embracing on the production-inducing effect and value added inducing effect. The health care industry R&D induces the production of 4,932 billion won and the value added of 2163 billion won.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.167-197
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• 1991

This paper is intended as an introductory essay to explain endogenous changes in the scope of firm activities in the competitive structure of a deregulated, multi-product financial industry. Recently, the global financial industry has been experiencing a widespread reshuffling in its activities, reflecting both consolidation and specialization. The spread of the universal banking system, which involves the integration of various kinds of financial activities, has resulted in the so-called financial supermarket. At the same time, the traditional set of banking activities has been unbundled into so-called financial boutiques. A relevant question is where the current reshuffling process of integration and disintegration in financial activities might lead the financial industry. However, presently popular theories of the financial industry are not really appropriate for the analysis of this issue. This paper attempts to integrate the theory of specialization [George J. Stigler, "The Division of Labor is Limited by the Extent of the Market," Journal of Political Economy, Vol. LIX, No.3, June 1951] and the theory of the multi-product firm [William J. Baumol, John C. Panzar, and Robert D. Willig, Contestable Markets and the Theory of Industry Structure, Harcourt Brace Jovanovich, Inc., New York, 1982] and to apply the resulting hybrid theory, a theory on the scope of financial activity, to the financial industry. The implications of this theory for the issues raised above are formalized under five hypotheses on the reshuffling of financial activities as listed below: Hypothesis I: The differences in the organization of financial industries among countries are determined by differences in the size of the financial markets, other things being equal. Hypothesis II: A financial firm will separate those financial activities simultaneously having relatively strong economies of scale and relatively weak economies of scope (alternatively, diseconomies of scope) from other activities. Conversely, the firm will integrate those activities simultaneously having relatively weak economies of scale (alternatively, diseconomies of scale) and relatively strong economies of scope with incumbent activities. Hypothesis III: A competitive equilibrium in the deregulated financial industry will consist of both specialized and multi-product financial firms, resulting in a mixed form of specialized and universal banking systems. Hypothesis IV: As world financial markets fully integrate and all countries consequently face this single, common world market, the financial structures of individual countries will become increasingly similar. Hypothesis V: A more universal banking system will dominate the deregulated financial industry in countries with relatively small financial markets, while a more specialized banking system will dominate in countries with relatively large financial markets. However, equilibrium will ultimately be mixed, with specialized and universal banks coexisting, as stated in Hypothesis III. Based on these hypotheses, this paper interprets the historical development of specialized vs. universal banking systems in major industrial countries as a process driven by the evolution of the financial market in each country - i.e. the change in the size of the financial market over time. In addition, this paper anticipates that the final equilibrium of the world financial industry, which is currently under the pressure of financial innovations and deregulation, will be a mixed equilibrium with both specialized boutiques and universal supermarket-type financial firms, instead of an exclusively specialized or universal banking system. Future research should seek continued theoretical elaboration and empirical verification of this paper's hypotheses.

• Journal of Technology Innovation
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• v.17 no.1
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• pp.119-148
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• 2009

The paper presents and empirically tests a model of the digital contents(DC) innovation systems that enables us to study interactions between users, service providers, contents developers and network providers, and to examine the relationship between manufacturing innovation and service innovation as well as patterns of innovation in the DC industry. The framework of Gallouj and Weinstein(1997) and Gallouj(2002) is modified into the DC innovation model according to characteristics of the DC industry, that is, user involvement and network externalities. The model is applied to a case analysis that traces the growth of the online game industry in Korea since its introduction. The model offers several advantages over other approaches in understanding the dynamics in the DC industry. Most importantly, it provides a single unified basis within which both service innovation resulting from users and service providers and manufacturing innovation induced by contents developers, platform holders and network providers are analyzed. The distinction between service and manufacturing innovation is important in many ways, for instance in selecting proper government policy tools for promotion or regulation of the DC industry. Second, the Korean online game industry has experienced both radical innovation during the beginning period and non-radical innovation throughout the maturation period. The model developed herein helps to illustrate several types of non-radical innovations such as recombinative innovation that are crucial to sustainable development of the DC industry. Third, the model clarifies impacts of network externalities that are characteristics of the DC industry.