• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2331-2338
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• 2014

The HEMP threat may have acquired new, and urgent, relevance as the proliferation of nuclear weapons and missile technology accelerates of the North Korea, for example, is assessed as already having developed few atomic weapons, and is on the verge of North Korea already has missiles capable of delivering a nuclear warhead against South Korea. ITU K.78, K81 and IEC recommended its counter-measuring for the industrial facilities with navigation and sailing facilities in order to obviate the all of processor equipped system malfunctions from the EMP/HEMP but its simulation must only be done by the computer simulation which had studied on the 1960-1990 years USA/AFWL papers. This result has a significant activities to the South Korea being under the North Korea threat because all of HEMP related products was strongly limited for export. The HEMP cord which was developed newly by the KTI including the HEMP generation & propagation analysis, optimal shelter design tool, essential EM energy attenuation in multi-layered various soils and rocks and HEMP filter design tool. Especially, the least square fitting method was adopted to analysis for the EM energy attenuation in the soils and rocks because it has a various characteristics based on the many times field test reports.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.420-425
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• 1999

The maximum demand controller is an electrical equipment installed at the consumer side of power system for monitoring the electrical energy consumed during every integrating period and preventing the target maximum demand (MD) being exceeded by disconnecting sheddable loads. By avoiding the peak loads and spreading the energy requirement the controller contributes to maximizing the utility factor of the generator systems. It results in not only saving the energy but also reducing the budget for constructing the natural base facilities by keeping thc number of generating plants ~ninimumT. he conventional MD controllers often bring about the large number of control actions during the every inteyating period and/or undesirable loaddisconnecting operations during the beginning stage of the integrating period. These make the users aviod the MD controllers. In this paper. fuzzy control technique is used to get around the disadvantages of the conventional MD control system. The proposed MD controller consists of the predictor module and the fuzzy MD control module. The proposed forecasting method uses the SOFM neural network model, differently from time series analysis, and thus it has inherent advantages of neural network such as parallel processing, generalization and robustness. The MD fuzzy controller determines the sensitivity of control action based on the time closed to the end of the integrating period and the urgency of the load interrupting action along the predicted demand reaching the target. The experimental results show that the proposed method has more accurate forecastinglcontrol performance than the previous methods.

• Journal of Christian Education in Korea
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• v.67
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• pp.415-447
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• 2021

The purpose of this study is to explore the direction that Christian education should take as an ecological education in the crisis of climate change. What climate change shows is that it is impossible to survive even if the Earth's temperature rises by only 2-3 degrees. However, our current appearance is concerned about the crisis of climate change as long as we do not change our lives. First, the meaning of climate change and its causes were examined. The anthropocentric worldview, modern industrial, scientific and technological growth, and consumption-oriented social structure can be cited as the causes. An anthropocentric worldview justifies everything from the human point of view, and nature is the subject of human domination, but one regarded as a tool. In addition, as the scale of human economic activity increases, energy consumption increases, and the threat of ecosystem destruction increases with the increase in energy consumption. Individual affluence and increased consumption are exacerbating ecosystem tensions. In order to solve the problem of climate change, ecological education clues were found in the Bible. Through creation, the relationship between humans and nature was identified as coexistence and coexistence. Through the principle of sabbath, it is possible to bring about the restoration of humans and nature, and from the point of view of the incarnation, the world was understood as the 'body' of God. Based on these clues, the direction of Christian ecological education was explored by suggesting a transition to an ecological paradigm, restoration of creative spirituality, and cultivation of ecological imagination. In the crisis of climate change, it is hoped that the recovery of the earth will take place and that we will be able to stand again as a responsible being through the Christian ecological educational approach.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.172-177
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• 2021

As part of the digital era, a digital twin that simulates the weak part of a product by performing a stress test that reduces the lifespan of some expensive equipment that cannot be done in reality by accurately moving the real world to virtual reality is being actively used in the manufacturing industry. Due to the development of IoT, the digital twin, which accurately collects data collected from the real world and makes it the same in the virtual space, is mutually beneficial through accurate prediction of urban life problems such as traffic, disaster, housing, quarantine, energy, environment, and aging. Based on its action, it is positioned as a necessary tool for smart city construction. Although digital twin is widely applied to the manufacturing field, this study proposes a smart city model suitable for the 4th industrial revolution era by using it to smart cities and increasing citizens' safety, welfare, and convenience through the proposed model. In addition, when a digital twin is applied to a smart city, it is expected that more accurate prediction and analysis will be possible by real-time synchronization between the real and virtual by maintaining realism and immediacy through real-time interaction.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.95-114
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• 2021

This study is to study the effect of corporate performance compensation system on organizational effectiveness and motivation, and the effect of organizational effectiveness and motivation on corporate performance, targeting employees of automobile maintenance service companies. 430 questionnaires obtained through the survey were used for the study. As a result of testing the research hypothesis, tangible reward had a significant positive (+) effect on job satisfaction, but intangible reward had a positive (+) effect on job satisfaction, but it was not significant. Also, tangible and intangible rewards have a significant positive (+) effect on organizational commitment and motivation. Job satisfaction has a significant positive (+) effect on productivity and service quality. However, organizational commitment had a significant positive (+) effect on productivity, but had a positive (+) effect on service quality, but was not significant. Lastly, motivation has a significant positive (+) effect on productivity and service quality. Through the research results, the relationship structure between the performance compensation system, organizational effectiveness and motivation, and corporate performance was identified, and the application of the performance compensation system to employees in the automobile industry was presented.

• International Area Studies Review
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• v.20 no.1
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• pp.23-51
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• 2016

This study analyzed the expected economic effects of the Korea-GCC FTA and sought strategies for industrial cooperation. To see the economic effects of Korea-GCC FTA, we analysed the effect of the oil tariff reduction of economy by Vector Autoregression(VAR) model. The estimation results shows that following the abolishment of the tariff on crude oil imports, GDP, GNI and consumption are expected to grow by 0.212%, 0.389% and 0.238%, respectively. Meanwhile, investment, export and import are estimated to drop by 0.462%, 0.413% and 0.342%, respectively. As for prices, producer prices are to rise by 6.356%p, whereas consumer prices fall by 2.996%p. In short, the Korea-GCC FTA and resultant abolishment of the tariff on crude oil imports followed by the decline in crude oil prices will result in declining prices whilst macroeconomic indices, such as GDP, GNI and consumption, will increase exerting positive effects on domestic economic growth. Also, it is necessary to proactively respond to GCC member states' industrial diversification policies for FTA-based industrial cooperation to diversify the sources of crude oil and natural gas imports for further resource risk management.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.76-89
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• 2018

The distribution of the combined heat and power system is active as a solution to the instability of energy supply and environmental pollution caused by continuous industrial development. In Korea, the safety standards for combined heat and power system using a gas engine are insufficient therefore the study on this is needed. In this study, the safety performance and structural/material assessment items of domestic and international standards applied to the combined heat and power system were analyzed to carry out a standardization study on safety performance applicable to 20 kW gas engine combined heat and power system. In addition, the safety performance assessment (plan) of the gas engine combined heat and power system was derived by performing risk analysis and risk assessment using HAZOP. Assessment items include engine ignition systems related to safety performance, piping tight performance, watering and temperature rise performance, combustion performance, electrical efficiency, thermal efficiency, overall efficiency and humidity performance. Gas and water pipes, gas control and shut-off valves, durability, heat resistance, and cold resistance of metal or non-metallic materials related to the structure and materials of the gas engine combined heat and power systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.179-184
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• 2019

In many countries, such as developing countries where electricity is scarce, small wind turbines in the form of Off Grid are an effective solution to solve power supply problems. In some countries, the expansion of power systems and the decline of electricity-intensive areas have led to the use of small wind power in urban road lighting, mobile communications base stations, aquaculture and seawater desalination. With this change, the size of the small wind power industry is expected to have greater potential than large-scale wind power. In the case of small wind power generators, the generator is controlled at a variable speed, and the voltage and current generated by the generator have many harmonic components. To solve this problem, the AC to DC converter to be studied in this paper is a three-phase step-up type converter with a single switch. The inductor current is controlled in discontinuous mode, and has a characteristic of having a unit power factor by eliminating the harmonic of the input current. The proposed converter is composed of LCL filter and three phase rectification boost converter at the input stage and a single phase full bridge for grid connection. It is a control system with energy storage system(ESS) that the system stabilization can be pursued against the electric power.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.115-131
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• 2011

Out of all the possible actions that can be taken to respond to greenhouse gas reduction, including development of greenhouse gas reduction technology, infrastructure, actions to improve energy saving and efficiency, and offset with carbon emission reductions (CERs), this study shall focus on the investment on CERs. This study will take a look at risks involved with investing in CERs such as UN registration refusal risk and CERs price fluctuation, and will design risk management model which shall be verified. The goal of this paper is to provide optimized CERs investment strategies for different types of investors, such as general trading companies seeking for investment opportunities and financial companies with plans for green products development and investment by preparation for carbon market. It is expected that the global competitiveness of domestic financial companies shall be improved by taking actions on carbon market instead of previous passive response to climate change and that Korea, the number two Carbon Emissions supplier and number one derivatives market in terms of volume, shall be able to lead the worldwide carbon market.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.590-596
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• 2019

Uses of fossil fuels like coal and oil increases with industrial development, and problems like abnormal climate come up as greenhouse gas increases. Accordingly, studies are actively conducted on eco-friendly renewable energy as a replacement for the main resources, and especially, wood pellets with high thermal efficiency are in the limelight as an alternative fuel in thermal power stations and gas boilers. However, despite a constant increase in their usage, few studies are conducted on their risks like fire and spontaneous combustion. Thus, this study found the auto-ignition temperature and critical ignition temperature of wood pellets with a change in flow rate in a thermostatic bath, using a sample vessel with 20 cm in length, 20 cm in height and 14 cm in thickness to predict their ignition characteristics. Consequently, at the flow rate of 0 NL/min, as the core temperature of the sample increased to higher than the ambient temperature, they ignited at $153^{\circ}C$, when the critical ignition temperature was $152.5^{\circ}C$. At the flow rates of 0.5 NL/min and 1.0 NL/min, it was $149.5^{\circ}C$, and at the flow rate of 1.5 NL/min, it was $147.5^{\circ}C$. Consequently, at the same storage, the more the flow rate, the lower the critical ignition temperature became.