• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.27-48
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• 2021

We extend and modify the canonical epidemiology model of Eichenbaum, Rebelo and Trabandt (2020) to investigate the general equilibrium effects of COVID-19 spread in the Korean economy when vaccine, treatment and social distancing are available. Particularly, we develop a SIR-macro model which considers possibility of moral inattention of the overconfident agents through which people is more likely to be infected. Our model implies that people's decision to cut back on consumption and work reduces the severity of the epidemic and thus exacerbate the size of the economic recession caused by the epidemic. Another finding is that the average 13 weeks to develop the vaccine and treatment will lead to 2% drop of consumption.

• The Journal of Fisheries Business Administration
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• v.23 no.2
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• pp.53-67
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• 1992

It has been recognized, virtually from the time of its inception, that fisheries economics, like other aspects of resource economics, should ideally be cast in capital-theoretic terms. The fish population or biomass can be viewed as a capital stock in that, like conventional or man-made capital, it is capable of yielding a sustainable consumption flow through time. This study is to introduce the optimal control theory which was extended from the theory of calculus of variations into the study of former static theory of fisheries economics started by Gordon (1954). The optimal control theory eliminated the inadequacies of the classical techniques to a large extent. From this point of view, this study, on the base of Schaefer model, summerizes most of major results achieved so far, but does so in a manner such that the links with capital theory are made transparent. This study explores two sets of problems. The first concerns the optimal approach to the equilibrium stock, i.e. the optimal investment policy. The second set of problems arises from the relaxation of the highly restrictive assumption of autonomy (i.e. the assumption that the parameters are independent of time), then concludes the relaxation of linearity assumption together with the complexities caused by that.

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.337-347
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• 2008

Based on social welfare maximum theory, the optimal scale of power plants entering generation power market being is researched. A static non-cooperative game model for short-term optimization of power plants with different cost is presented. And the equilibrium solutions and the total social welfare are obtained. According to principle of maximum social welfare selection, the optimization model is solved, optimal number of power plants entering the market is determined. The optimization results can not only increase the customer surplus and improve power production efficiency, but also sustain normal profits of power plants and scale economy of power production, and the waste of resource can also be avoided. At last, case results show that the proposed model is efficient.

• Journal of Korean Library and Information Science Society
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• v.29
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• pp.1-25
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• 1998

Effectiveness is a major concern in organizations of all sorts. Library researchers have been particularly active recently in trying to define, measure, and promote library effectiveness. The purpose of this study is to place library effectiveness in the context of theoretical and empirical work on organizational effectiveness. Four major approaches to organizational effectiveness can be identified. The goal model defines an effective organizations as one that meets its goals. The system resource model emphasizes the organization's need to acquire resources from its environment. The process model sees organizations as social systems seeking to survive and maintain their equilibrium. The multiple constituencies defines effectiveness as the degree to which the needs and expectations of strategic constituencies are met. These models are not necessarily contradictory but may be seen as emphasizing different aspects of organizational performance or values. This study also reports four findings of the library effectiveness. They are significant as the empirical investigation into the dimensions of the construct of library effectiveness. The result shows that organizational effectiveness of libraries is, indeed, a multidimensional construct, implying that no single measure of effectiveness is sufficient to describe an organization.

• Journal of the Korean Regional Science Association
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• v.13 no.2
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• pp.75-92
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• 1997

This paper is concerned with an estimation of optimal investment of road sector in 1996-2005. The main method is a Computable General Equilibrium (CGE) Model for Korea in which the optimal solution is derived in a recursively dynamic path. The model is composed of three main modules: the supply, the demand and the price. In this paper, the investment demand for the road is optimized with subject to national economic growth and price inflation. If the annual inflation level and the economic growth rate during 1996-2005 are set to 4.5%-5.0% and 6.0%-6.5% respectively, the optimal demand for the road investment is estimated as 155.1-180.1 trillion Won or 3.33%-3.89% of the GDP for ten years. It implies that the additional increase of the road investment by 0.61%-1.15% of the GDP is required for sustainable economic development, since the share of the road investment in the GDP of the latest 5 years has stayed around 2.27%. However, it is necessary to reduce construction investments on housing as well as to promote private financing of the road in order to maximize an efficiency of resource allocation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.1998-2014
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• 2016

In recent years, cloud computing services based on smart phones and other mobile terminals have been a rapid development. Cloud computing has the advantages of mass storage capacity and high-speed computing power, and it can meet the needs of different types of users, and under the background, mobile cloud computing (MCC) is now booming. In this paper, we have put forward a new classification-based virtual machine placement (CBVMP) algorithm for MCC, and it aims at improving the efficiency of virtual machine (VM) allocation and the disequilibrium utilization of underlying physical resources in large cloud data center. By simulation experiments based on CloudSim cloud platform, the experimental results show that the new algorithm can improve the efficiency of the VM placement and the utilization rate of underlying physical resources.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.462-472
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• 2014

This study is aimed at developing a supply-demand model of wood products, and outlook for mid-term and long-term supply and demand for each products. The main wood products include sawnwood, plywood, particle board, fiberboard (MDF), and pulp. The partial equilibrium model is composed of supply function, import demand function, demand function, price relation function. With given parameters the outlook for year 2050 says that sawnwood, plywood, and fiberboard for domestic productions and imports are decreased. This may result from the increase of log prices from the inside and outside of the country because of the propensity for environment protection and the resource nationalism. On the other hand the supply of particle board and pulp will increase because they are made from wasted wood and chips.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4188-4206
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• 2016

Power control is widely used to reduce co-channel interference in wireless networks and guarantee the signal-to-interference plus noise ratio (SINR) of ongoing connections. This technique is also effective for wireless body area networks (WBANs). Although achieving satisfactory SINR is important for WBAN users, they may not be willing to achieve it at arbitrarily high power levels since power is a scarce resource in WBANs. Besides, for WBANs with different purposes, the QoS requirements and concern about the power consumption may be different. This motivates us to formulate the power control problem using the concepts from microeconomics and game theory. In this paper, the QoS objective is viewed as a utility function, which represents the degree of user satisfaction, while the power consumption is viewed as a cost function. The power control problem consequently becomes a non-cooperative multiplayer game, in which each player tries to maximize its net utility, i.e., the utility minus the cost. Within this framework, we investigate the Nash equilibrium existence and uniqueness in the game and derive the best response solution to reach the Nash equilibrium. To obtain the optimal transmission power in a distributed way, we further propose a utility-based and QoS-aware power control algorithm (UQoS-PCA). Tunable cost coefficient in UQoS-PCA enables this scheme to be flexible to satisfy diverse service requirements. Simulation results show the convergence and effectiveness of the proposed scheme as well as improvements over existing algorithm.

• Environmental Engineering Research
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• v.25 no.4
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• pp.536-544
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• 2020

To address organic dye wastewater, economic and effective adsorbents are required. Here, magnetic biochar from alkali-activated rice straw (AMBC) was successfully synthesized using one-step magnetization and carbonization method. The alkaline activation caused the large specific surface area, high pore volume and abundant oxygen-containing groups of the AMBC, and the magnetization gave the AMBC a certain degree of electropositivity and fast equilibrium characteristics. These characteristics collectively contributed to a relative high adsorption capacity of 53.66 mg g^-1 for this adsorbent towards rhodamine B (RhB). In brief, RhB can spontaneously adsorb onto the heterogeneous surface of the AMBC and reach the equilibrium in 60 min. Although the initial pH, ionic strength and other substances of the solution affected the adsorption performance of the AMBC, it could be easily regenerated and reused with considerable adsorption content. Based on the results, H-bonds, π-π stacking and electrostatic interactions were speculated as the primary mechanisms for RhB adsorption onto the AMBC, which was also demonstrated by the FTIR analysis. With the advantageous features of low cost, easy separation, considerable adsorption capacity and favorable stability and reusability, the AMBC would be a potential adsorbent for removing organic dyes from wastewater.

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.103-112
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• 2006

Priority-based network service has been widely adopted for the Internet traffic management in the context of IETF differentiated services, and computing optimal prices for such priority-based service is the key topic in many pricing literature. While the equilibrium analysis has been commonly used to this end, many have criticized the validity of the underlying assumption of equilibrium analysis that user utility functions are precisely known. In this paper, we propose a solution for bridging the gap between the existing theoretical work on optimal pricing and the unavailability of precise user utility information in real networks. In the proposed method, the service provider obtains more and more accurate estimates of user utility functions from the initial imprecise knowledge by iteratively changing the price of service levels and observing the users' decisions under the changed price. Our contribution is two-fold. First, we have developed a general principle for estimating the user utility functions. Second, we have developed a novel method for setting the prices that can optimize the extraction of the knowledge about user utility functions. The extensive simulation results demonstrate the effectiveness of our method.