• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.52-59
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• 2008

This paper describes the secant method for solving the economic dispatch (ED) problem with generator constraints and transmission losses. The ED problem is an important optimization problem in the economic operation of a power system. The proposed algorithm involves selection of minimum and maximum incremental costs (lambda values) and then the evaluation of optimal lambda at required power demand is done by secant method. The proposed algorithm has been tested on a power system having 6, 15, and 40 generating units. Studies have been made on the proposed method to solve the ED problem by taking 120 and 200 units with generator constraints. Simulation results of the proposed approach were compared in terms of solution quality, convergence characteristics, and computation efficiency with conventional methods such as lambda iterative method, heuristic methods such as genetic algorithm, and meta-heuristic methods like particle swarm optimization. It is observed from different case studies that the proposed method provides qualitative solutions with less computational time compared to various methods available in the literature.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.1
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• pp.1-8
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• 1992

Hopfield neural network has been applied to the problem of economic load dispatch(ELD) of electric power. The optimum values of neuron potentials are represented in terms of large numbers. The differential synchronous transition mode is used in this simulation. Through case studies, we have shown the possibility of the application of neural network to ELD. In case of including the transmission losses, the proposed method has an advantage that the problem can be solved simply with one neural network, without calculating incremental fuel costs and incremental losses required by traditional method.

• KDI Journal of Economic Policy
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• v.35 no.1
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• pp.1-32
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• 2013

Economic sanctions and inducements are types of 'policy instruments' based on 'economic tools' to influence other international actors. Ongoing debates on sanctions and inducements have exposed drawbacks for relying on individual case studies. There are some studies in the literature that attempt theoretical analysis of sanctions and inducements, but they are mostly based on rational choice theory. In reality, however, there exist so many cases that cannot be explained by rational choice theory. These are called anomalies or exceptions. The literature introduces specific variables to interpret these anomalies and thus sacrifice the universality of the theory. From this point of view, prospect theory would present an effective tool to analyze economic sanctions and inducements. It is a behavioral economic theory that tries to model a decisions making process in reality. The theory says that people make decisions based on subjective value of losses and gains from an individual reference point, and that people evaluate these losses and gains using heuristics. Thus prospect theory could offer a different frame which has greater explanatory range without adding new variables. As a result of this study, target's losses of 'back down' towards economic sanctions loom larger when the reference point level increases, therefore, the effectiveness of sanctions decreases. However, target's losses of 'stand firm' towards economic inducements loom larger under the same condition of reference point, therefore, the effectiveness of inducements increases. The findings of the paper suggest meaningful implications to the economic policy towards North Korea.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.618-627
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• 2019

An increase in damage to crops and facilities caused by wildlife such as wild boar causes serious social and economic problems to the rural economy in Korea. This study aims to estimate the economic losses incurred to rural households in mountain villages near protected areas in Korea due to the damage to agricultural and forestry production by wildlife. The case of mountain villages located in Toji-myeon, Gurye-gun near the Jirisan National Park was studied as an example. Data were collected by interviewing 84 households across six mountain villages in April and June 2016. The results indicate that the economic losses due to wildlife damage in 2015 were estimated to be 1.65 million KRW per household, which is a total of 138.63 million KRW for the 84 households. Among local products, the most damaged products were chestnut, fern-brake, wild pear, peach, and potato, whereas the most damaged products per production area were sweet potato, peach, corn, and potato. The potential economic losses caused by wildlife damage to agricultural and forestry production in whole Gurye-gun area was estimated to be around 4.0 billion KRW in 2015. However, the municipal government budget for the compensation of wildlife damage was only 0.9 percent of the potential rural economic losses caused by wildlife damage in 2015. The results of our study suggest that the compensation scheme for wildlife damage is inadequate in the respect of social justice. Considering the low financial capacity of the municipalities in mountain areas, the central government should take a progressive responsibility by allocating more financial resources for compensation of economic losses of rural households due to wildlife damage. The equitable and effective governance of wildlife conservation is required for sustainable development of rural communities near protected areas.

• Journal of Labour Economics
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• v.33 no.1
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• pp.53-84
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• 2010

This paper investigates the wage losses of displaced workers, using data from the Korean Labor & Income Panel Study. Previous Korean studies were only to estimate the wage losses shortly after job displacement. However, if the wage losses persist, those results seem to under-estimate the effects of displacement. Our findings show that the wage reductions are quite persistent 4 years after displacement. And much of this persistence can be explained by the lost labor market experience (lost opportunities to accumulate generalized skills) and additional job losses in the years following an initial displacement.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.567-575
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• 2019

Statistics show that while the number of fires has decreased over the last decade, losses of human life and economic property due to fire have increased. Moreover, the number of large-scale fires that have occurred in recent years has resulted in heightened public anxiety. This study aims to identify a specific period of the year most vulnerable to fire, and fire trends, such as damage of fire to humans, to the economy, and different building types. For this purpose, we analyzed human and economic damages using statistics related to fire from 2007 to 2017 and provided a monthly distribution of fire damages both to humans and to the economy by building type. We also identified the relationship between the human damage and the economy damage, and compared the economic losses per casualty by building type. The human damage in residential buildings occupied the highest portion, whereas the economic damage of industrial buildings represented more than a half of all economic damage due to fire. The economic damage per casualty was shown highest for industrial buildings and has also increased rapidly in recent years.

• Journal of International Area Studies (JIAS)
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• v.18 no.3
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• pp.145-168
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• 2014

Given the distance from Mt. Baekdu, volcanic ash will have the direct impact on South Korea in case Mt. Baekdu erupts. Ash fall deposits or particulate matters(PM10) in the air will cause damages in various sectors. In particular, the PM10 impact on the manufacturing sector when the ash disperses in Korea is needed to be assessed since South Korea's manufacturing sector accounts for more than 30% of GDP. Meanwhile the economic impacts of PM10, including Asian dust, have been researched in Korea as the events become frequent, and losses in the manufacturing have been also reported. This study is to identify vulnerable sectors to volcanic ash in the korean industry, and to assess economic losses in case of a Mt. Baekdu eruption scenario, based on the historical loss experience with particulate matters. Study results show that airline, precision such as electronics and semiconductors, distribution, shipbuilding, car, leisure, glass, dairy farming are vulnerable to volcanic ash, or PM10. The economic losses in both car and shipbuilding industry is estimated to 46.49 billion Korean won due to shutdown for 6 hours in case of a Mt. Baekdu eruption scenario.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.681-688
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• 2012

This paper presents the application of Differential Evolution (DE) algorithm to obtain a solution for Bid Based Dynamic Economic Dispatch (BBDED) problem including the transmission losses and to maximize the social profit in a deregulated power system. The IEEE-30 bus test system with six generators, two customers and two trading periods are considered under various bidding strategies in a day-ahead electricity market. By matching the bids received from supplying and distributing entities, the Independent System Operator (ISO) maximize the social profit, (with the choices available). The simulation results of DE are compared with the results of Particle swarm optimization (PSO). The results demonstrate the potential of DE algorithm and show its effectiveness to solve BBDED.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.16-21
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• 2012

The growth in IT industry has brought a corresponding rise in the number of connected digital devices in the distribution network. These digital loads lead to AC to DC conversion losses in order to supply power to them. The more the renewable energies and plug-in electrical vehicles penetrated our lives, the more the electrical losses are caused by AC to DC conversion process. Hence, this paper suggests the methodology for evaluating the amount of power supplied according to the ratio of DC power supply and performs an economic analysis of DC distribution system considering grid parity. In here, the cost of carbon emission reduced by renewable energy is also concerned.

• KDI Journal of Economic Policy
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• v.43 no.2
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• pp.23-51
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• 2021

The persistence of the employment shock by COVID-19 has various policy implications during the pandemic and beyond it. After evaluating the impact of the health crisis at the individual level, this study decomposes employment losses into persistent and transitory components using the observed timing of the three major outbreaks and subsequent lulls. The estimation results show that while face-to-face services were undoubtedly hit hard by the COVID-19 crisis, the sectoral shock was less persistent for temporary jobs and self-employment. Permanent jobs in the hard-hit sector showed increasingly large persistent losses through the recurring crises, indicating gradual changes in employer responses. The persistent job losses were concentrated on young and older workers in career transitions, whose losses are likely to have long-term effects. These results suggest that targeted measures to mitigate the persistent effects of the employment shock should take priority during the recovery process.