• Journal of Industrial Convergence
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• v.1 no.1
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• pp.127-142
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• 2003

This Study examines the implications for event studies using the daily stock data. The output present the event study results. The event period is defined from 30 days before through 30 days after the event date, and is broken into four "windows" for abnormal return cumulation: the pre-event period, days -30 through -2; dajys -1 and 0, a period commonly investigated for the immediate impact of the event; and the post-event period, days +1 through +30. It shows how firm's information offerings affect the price process and consequent issues. The Patell Z test is an examples of a standardized abnormal return approach, which estimate a separate standard error for each security-event and assumes cross-sectional independence. The generalized sign test adjusts for the fraction of positive abnormal returns in the estimation period instead of assuming 0.5.

• Korean Security Journal
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• no.12
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• pp.117-147
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• 2006

This study aims to propose efficient way to operate the security guarding system from the perspective of administration, policy, law, institution and operation as to the private security guarding system as the Korean security guarding system needs multifaced analysis and measure to ensure efficient operation. The growth strategy has to be restructured and segmentation market needs to be driven in order to cope with the changing conditions of company from the perspective of administration. And private security guarding service companies must refrain from excessive competition while improving the contracting method such as minimum price bidding, etc. From the perspective of policy, the functions of relevant organizations such as the National Police Agency, security association, etc, and mutual cooperation must expand. Also, the profit generation event needs to be privatized and the more positive perception toward the private security guarding service is necessary. In addition, security exhibition and seminar can be expanded to lay the groundwork for the advancement of private security system. From the legal and institutional perspective, the security guarding service related law must be revised and the certification system must b introduced to cope with the changing requirement. The security guarding instructor system must be strengthened to ensure a faithful and earnest implementation of duty to instruct, supervise and educate security guarding personnel. From the perspective of security guarding system's operation, professional security technique must be introduced and applied, and the volunteer application system must be established. In addition, standard 'security guarding manual' must be crafted, and the equipment for security guarding must be modernized to ensure an efficient operation of private security guarding services.

• Communications for Statistical Applications and Methods
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• v.22 no.1
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• pp.31-40
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• 2015

This study proposes a mathematical model that can forecast national defense expenditures. The ongoing European debt crisis weighs heavily on markets; consequently, government spending in many countries will be constrained. However, a forecasting model to predict military spending is acutely needed for South Korea because security threats still exist and the estimation of military spending at a reasonable level is closely related to economic growth. This study establishes two models: an Auto-Regressive Moving Average model (ARIMA) based on past military expenditures and Transfer Function model with the Gross Domestic Product (GDP), exchange rate and consumer price index as input time series. The proposed models use defense spending data as of 2012 to create defense expenditure forecasts up to 2025.

• Korean Journal of Organic Agriculture
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• v.32 no.2
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• pp.137-159
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• 2024

Major crop prices have been raised significantly in recent years by COVID-19, the war in Ukraine, and weather-induced reductions in South American soybean production by unfavoured weather in 2022. Rising international crop prices are likely to destabilize food security in South Korea, which is highly dependent on foreign crops. This study analyzed the impact of soybean import price changes on the domestic soybean market and soybean food self-sufficiency rate from 2024 to 2029 using a dynamic partial equilibrium model. According to the scenario analysis results, if the import prices rise by 10% compared to the baseline, the soybean food self-sufficiency rate would increase by 1.33% in 2024, but it is expected to decrease to -0.58% in 2029 due to the continuous decrease in production. The results of this study are expected to be used as valuable information for policy authorities in establishing policies related to improving food self-sufficiency.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.7
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• pp.381-386
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• 2003

To provide a specified power quality under electric market system is becoming an important issue for customers and utility company. However, there is no realistic infra-structure to design a power system for the specified power quality. Present electric market is operating under the economic point of view. The low power price could be attractive, but the effect of low price could result the lower power quality for the long time and threat power system security. This paper presents a model which conceptualize the dynamic power quality control mechanism to minimize total cost of a society which is affected electric power quality. This model aims to produce a basic infra-structure to balance cost and quality under the electric market system.

• Journal of the Korean Statistical Society
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• v.35 no.2
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• pp.115-142
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• 2006

This paper studies the problem of option hedging when the underlying asset price process is a compound Poisson process. By adopting an asymptotic approach to let the security price converge to a continuous process, we find a closed-form hedging strategy that improves the classical Black-Scholes hedging strategy in a quadratic sense. We first show that the scaled Black-scholes hedging error has a limit in law, and that limit is decomposed into a part that can be traded away and a part that is purely unreplicable. The Black-Scholes hedging strategy is then modified by adding the replicable part of its hedging error and by adding the mean-variance hedging strategy to the nonreplicable part. Some results of simulation experiment s are also provided.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.438-440
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• 2002

In deregulated power market, transmission pricing methodology should maintain non-discrimination amongst all participants while ensure that TRANSCOs recover their revenue requirements. The proposed transmission pricing methodology for Korea needs cost allocation ratios, such as allocation ratio of physical transport to network security and that of generators to loads. In this paper, we studied the nodal transmission price determined by the cost allocation factors and its influence on GENCOs and DISTCOs.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.89-94
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• 2022

The Saudi Vision 2030 defined the directions of the national economy and market towards diversifying sources of income, and developing energy to become less dependent on oil. The study sought through a theoretical review to identify the reality of the energy sector and the areas of investment available in the field of renewable energy. Findings showed that investment in the renewable energy sector is a promising source according to solar, wind, hydrogen, geothermal energy and burning waste than landfill to extract biogas for less emission. The renewable energy sector faces challenges related to technology, production cost, price, quantity of production and consumption, and markets. The study revealed some recommendations providing and suggested electronic marketing system to provide investors and consumers with energy available from renewable sources.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.409-414
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• 2021

Geographic Information Systems (GIS) is considered to be one of the most important technologies provided by the Internet in our era. GIS enables institutions and individuals to plan and make decisions in many fields. GIS assists in accessing new and updated information on planning process. GIS also enables determining distances such as length, width, area on a map, and allows analyzing and processing a large amount of data for the search of geographical characteristics of locations. This paper explains the concept of dispensing prescription through the specific code of drug on an electronic system using GIS technology. The proposed methodology aims to inform patients of all the prescriptions dispensed and to help individuals inquiring about prescription at the nearest pharmacy through GIS technology. This proposed methodology is considered significant in some cases, as the patient does not know price, specifications and pharmacy location where the drug required is available, thus increasing the time and effort cost that is spent searching for the prescription.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.337-345
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• 2009

Deregulation in power industry has made the reactive power ancillary service management a critical task to power system operators from both technical and economic perspectives. Reactive power management in power systems is a complex combinatorial optimization problem involving nonlinear functions with multiple local minima and nonlinear constraints. This paper proposes a practical market-based reactive power ancillary service management scheme to tackle the challenge. In this paper a new model for voltage security and reactive power management is presented. The proposed model minimizes reactive support cost as an economic aspect and insures the voltage security as a technical constraint. For modeling validation study, two optimization algorithm, a genetic algorithm (GA) and particle swarm optimization (PSO) method are used to solve the problem of optimum allocation of reactive power in power systems under open market environment and the results are compared. As a case study, the IEEE-30 bus power system is used. Results show that the algorithm is well competent for optimal allocation of reactive power under practical constraints and price based conditions.