• Environmental and Resource Economics Review
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• v.26 no.1
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• pp.57-83
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• 2017

The Japanese government's attempts to reduce fine particles (PM2.5) emission pollution in Japan have been largely ineffective. This is because PM2.5 in Japan originated from various sources including around half from oversea countries such as China. This prompts the Japanese government to start a new initiative to reduce PM2.5 at its origin by transferring local knowledge on air pollution reduction measures and technologies to China and working closely with the Chinese government. To promote further reduction in PM2.5, bilateral corporation between Japan and China should be extended to include Korea. It is recommended that an international convention should be in place to deal with transboundary air pollutants in East Asia. A successful East Asia corporation to reduce PM2.5 will not only contribute to clean air but also to future sustainable low carbon society in this region.

• The Journal of Information Technology
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• v.4 no.3
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• pp.77-86
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• 2001

In this paper, Electromagnetic scattering problem by a resistive strip grating with 2 dielectric layers on a ground plane according as resistivity of resistive strip, relative permittivity and thickness of dielectric layers, and incident angles of a electric wave is analyzed by applying the PMM (Point Matching Method) known as a numerical procedure. The scattered electromagnetic fields are expanded in a series of floquet mode functions. The boundary conditions are applied to obtain the unknown field coefficients and the resistive boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip. According as the relative permittivity and the thickness of layers are increased, the values of the geometrically normalized reflected power have a high value and the values of strip width are moved toward a high value going from left to right. When the resistivity of this paper has a value of zero, the numerical results of the geometrically normalized reflected power show in good agreement with those by the PMM of existing paper. Then, the most energys of the sharp variation point in minimum values of the geometrically normalized reflected power are scattered in direction of the other angles except incident angle.

• The Korean Journal of Applied Statistics
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• v.32 no.5
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• pp.703-720
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• 2019

The influence of temperature on electricity demand is increasing due to extreme weather and climate change, and the climate impacts involves nonlinearity, asymmetry and complexity. Considering changes in government energy policy and the development of the fourth industrial revolution, it is important to assess the climate effect more accurately for stable management of electricity supply and demand. This study aims to analyze the effect of temperature change on electricity demand using the partial linear model. The main results obtained using the time-unit high frequency data for meteorological variables and electricity consumption are as follows. Estimation results show that the relationship between temperature change and electricity demand involves complexity, nonlinearity and asymmetry, which reflects the nonlinear effect of extreme weather. The prediction accuracy of in-sample and out-of-sample electricity forecasting using the partial linear model evidences better predictive accuracy than the conventional model based on the heating and cooling degree days. Diebold-Mariano test confirms significance of the predictive accuracy of the partial linear model.

• Journal of Korean Society of Steel Construction
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• v.21 no.6
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• pp.563-574
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• 2009

This paper briefly describes the fundamental strategies--path-tracing, pin-pointing, and path-switching--in the computational elastic bifurcation theory of geometrically non-linear single-load-parameter conservative elastic spatial structures. The stability points in the non-linear elasticity may be classified into limit points and bifurcation points. For the limit points, the path tracing scheme that successively computes the regular equilibrium points on the equilibrium path, and the pinpointing scheme that precisely locates the singular equilibrium points were sufficient for the computational stability analysis. For the bifurcation points, however, a specific procedure for path-switching was also necessary to detect the branching paths to be traced in the post-buckling region. After the introduction, a general theory of elastic stability based on the energy concept was given. Then path tracing, an indirect method of detecting multiple bifurcation points, and path switching strategies were described. Next, some numerical examples of bifurcation analysis were carried out for a trussed stardome, and a pin-supported plane circular arch was described. Finally, concluding remarks were given.

• Convergence Security Journal
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• v.20 no.5
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• pp.11-17
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• 2020

With the increase in cases of using Bluetooth devices used in the electric vehicle charging systems, security issues are also raised. Although various technical efforts have beed made to enhance security of bluetooth technology, various attack methods exist. In this paper, we propose an intelligent Bluetooth intrusion detection system based on a well-known machine learning method, Hidden Markov Model, for the purpose of detecting intelligently representative Bluetooth attack methods. The proposed approach combines packet types of H4, which is bluetooth transport layer protocol, and the transport directions of the packet firstly to represent the behavior of current traffic, and uses the temporal deployment of these combined types as the final input features for detecting attacks in real time as well as accurate detection. We construct the experimental environment for the data acquisition and analysis the performance of the proposed system against obtained data set.

• Journal of International Area Studies (JIAS)
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• v.13 no.2
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• pp.47-72
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• 2009

Since the Soviet Union collapsed, Russia has been aggressively seeking a role and place in the U.S.-led international order. Russia conditionally cooperated with the U.S. global policy, efforts to protect and expand the national interests in Post-soviet region. In this context, Post-soviet space is the arena of the struggle among the world powers. Especially in Ukraine as the Axis power of Post-soviet space, hegemony conflicts so called 'New Cold War' between Russia and western powers including U.S. have appeared. This paper examines what are Russian military security strategy and policy, how these come to fruition in Ukraine, what are important factors of complications and its aspect.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.161-163
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• 2021

This urban centralization is expected to develop rapidly, with 75% of the population living in the city by 2035. Large cities are becoming unsustainable due to side effects such as environmental pollution, severe traffic jams, excessive energy depletion, and destruction of the natural ecosystem. In addition, the happiness index of citizens of large cities is also falling because of high crime rates and safety accidents, the work-life imbalance caused by inequality and polarization, and overly competitive education. To solve this problem, Smart City, an IT-based future city model, was born. The Korean government is also actively attempting to improve urban competitiveness and promote sustainable development through efficient construction and operation of smart cities as a national focus project. To support the effort, we review the basic directions and strategies of Sejong City's Smart City service infrastructure based on the comprehensive national land plan, Smart City plan, and Smart City strategy plan.

• International Commerce and Information Review
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• v.13 no.3
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• pp.119-142
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• 2011

Competitions for secure oil are intense around the world due to the limited oil reserves. The situations are becoming more serious as China has participated in the competition. This paper aims to investigate China's offshore oil development strategies to balance the supply and demand of oil and then suggest its policy implications. A surging increase of oil demand due to the rapid economic growth as well as the stagnation in domestic oil output has turned China into a net oil importer since 1993. Therefore, China has placed a significant priority on securing long-term stability of its offshore oil to cope with the rapid growing demand. It has taken a variety of strategies to secure stable oil resource such as development of offshore oil resource, increasing the number of oil importing countries. China with the highest foreign exchange reserve of approximately $3 trillion as of 2010, has considered to employ foreign exchange reserves while making a huge amount of investment to secure oil resource. China has pursued several policies such as loan to oil production country for securing oil, foreign direct investment on offshore oil development, M&A of oil exploration and production companies and geographical diversification of oil importing countries. China has promoted offensive strategies for securing oil resource rather than cooperation with other countries. Thus, China should find a trade-off point for recovering relationship with international society while developing and investing renewable energy for long-term future. It will also address some implications for Korea, which has to prepare new strategies of overseas oil development.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.22-29
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• 2004

An international project, known as Argo, for collecting data on temperature, salinity and velocity of currents in the world's oceans, has been started in the year 2000 and the full Argo array of approximately 3000 floats will be deployed by 2006. 18 countries deployed 1,023 floats, which are operating in the ocean of the world as of December 2003. In the present study, we tried to predict float distribution and a rate of drifting ashore of the floats after their termination based upon a product of the ocean general circulation model of JAMSTEC (Japan Marine Science and Technology Center). We first evaluated reliability of the model prodilct quantitatively by comparing trajectories of surface buoys of WOCE Surface Velocity Program (SVP) and those predicted by the model surface current field. It is found that the model is acceptable for practical application to deploy floats and to estimate those trajectories. 653 particles at 3-degree spacing are used to investigate the ratio of floats drifted ashore, given that during the first 4 years floats cycle between the surface and 2000m for 10 days and then floats are on just the surface for 100 years. The simulation indicates that about 29% of deployed floats will be drifted ashore within 100-year.

• Land and Housing Review
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• v.2 no.4
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• pp.429-437
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• 2011

The purpose of this research is to seek the suggestions applicable to Korean green-growth(development) policy and the realization of low carbon society by looking around the promotion policy and the process, the promotion system, main environmental policy in each city about the business for environmental model city in Japan which has been promoted in a city in order to realize low-carbon society. Japan had selected 13 local governments as an environmental model city as a part of a policy to build low-carbon society in 2008~2009, and Japan has formed information sharing between cities and provinces, the spread of information sharing and the free competition among local governments for an environmental model city through Zero Carbon City Promotion Council consisting of local governments and specialists. When examining these cases in Japan, the green-growth policy promoting currently in Korea needs to be converted from the central government-dominated policy to the local government-dominated policy and Koreaneeds to make more effort to develop software programs in order to realize green-growth social system.