• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1383-1384
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• 2015

In this paper, a dynamics model embedded navigation filter is newly suggested for underwater autonomous systems without position or attitude aid. In order to ensure the observability on the INS errors, the hydrodynamics of the underwater vehicle is incorporated with the INS attitude error. This approach allows us to estimate and compensate the INS errors in spite of using external velocity sensor. Through the simulation, the performance and effectiveness of the proposed scheme are demonstrated.

• International Journal of Control, Automation, and Systems
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• v.4 no.3
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• pp.318-324
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• 2006

The mobile manipulator is expected to work in partially defined or unstructured environments. In our global/local approach to path planning, joint trajectories are generated for a desired Cartesian space path, designed by the global path planner. For a local path planner, inverse kinematics for a redundant system is used. Joint displacement limit for the manipulator links is considered in the motion planner. In an event of failure to obtain feasible trajectories, the task cannot be accomplished. At the point of failure, a deviation in the Cartesian space path is obtained and a replanner gives a new path that would achieve the goal position. To calculate the deviation, a nonlinear optimization problem is formulated and solved by standard Sequential Quadratic Programming (SQP) method.

• Coupled systems mechanics
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• v.1 no.1
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• pp.99-113
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• 2012

We present a monolithic semi-implicit algorithm for solving fluid-structure interaction problem at small structural displacements. The algorithm uses one global mesh for the fluid-structure domain obtained by gluing the fluid and structure meshes which are matching on the interface. The continuity of velocity at the interface is automatically satisfied and the continuity of stress does not appear explicitly in the global weak form due to the action and reaction principle. At each time step, we have to solve a monolithic system of unknowns velocity and pressure defined on the global fluid-structure domain. Numerical results are presented.

• International Commerce and Information Review
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• v.8 no.1
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• pp.227-242
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• 2006

The rapid expansion of regionalism has resulted in the creation of blocs of the global economy, so that those countries not belonging to one or more blocs can be discrimiated. Though signed on the bill of FTA with Chile, Korea is actually alienated from major stream of the blocs. Therefore, Korea government makes efforts to contract more FTAs with countries such as Singapore and Japan, others. FTA is believed to be an important method to secure export and national competitiveness. Therefore, we need to exactly understand critical issues and the long-run effort of FTA. This paper tries to find out important issues and potential strategies relating to electronic commerce in Korea's FTA with other countries. In these means, relationship between FTA and e-Trade are closely related to global business chance. In these means, we should use FTA potentials for encouraging global commerce by e-Trade and develop e-FTA in the foreseeable future.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.19-24
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• 2008

Many types of disasters are related to environmental problems. Today, frequently occurring disasters and global environmental problems have begun to threaten human life and welfare. Consequently, building sustainable communities requires assessing relationships between environmental problems and disasters using a broad, open approach and with a long-term perspective. This paper attempts to identify the need for conceptualizing disasters and environmental problems together by comparing mechanisms of both disasters and environmental problems, and attempts to integrate both of these seemingly different types of phenomena as similar types of risk threatening human existence. Based on this work, a chart is proposed for qualitatively organizing disasters, environmental problems and their mutual influences, as well as providing a framework for potential quantitative analysis. It is hoped this research serves to contribute to effective mitigation to both disasters and environmental problems in today's age of global environmental issues.

• Journal of Information Processing Systems
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• v.17 no.4
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• pp.737-753
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• 2021

As the demand for high-quality rendering for mixed reality, videogame, and simulation has increased, global illumination has been actively researched. Monte Carlo path tracing can realize global illumination and produce photorealistic scenes that include critical effects such as color bleeding, caustics, multiple light, and shadows. If the sampling rate is insufficient, however, the rendered results have a large amount of noise. The most successful approach to eliminating or reducing Monte Carlo noise uses a feature-based filter. It exploits the scene characteristics such as a position within a world coordinate and a shading normal. In general, the techniques are based on the denoised pixel or sample and are computationally expensive. However, the main challenge for all of them is to find the appropriate weights for every feature while preserving the details of the scene. In this paper, we compare the recent algorithms for removing Monte Carlo noise in terms of their performance and quality. We also describe their advantages and disadvantages. As far as we know, this study is the first in the world to compare the artificial intelligence-based denoising methods for Monte Carlo rendering.

• East Asian Economic Review
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• v.24 no.4
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• pp.389-416
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• 2020

This paper provides empirical evidence on the reorganization of GVCs in East Asia, highlighting that structural trends explain a decrease in the fragmentation of production after 2011 but that it is not the result of rising trade costs along the value chain. Using harmonized inter-country input-output tables, the paper first analyzes the global import intensity of production to document changes in the structure of GVCs. It then calculates theory-consistent bilateral trade costs for intermediate and final products using an approach derived from the gravity literature and introduces a new index of cumulative trade costs along the value chain. These data are used to discuss whether the decrease in global imports is the consequence of shifts in demand, efficiency-enhancing strategies of firms or rising trade costs. Between 2011 and 2016, cumulative trade costs have decreased in East Asian GVCs. However, as COVID-19 is likely to intensify trade and investment uncertainties, trade costs could increase in the future. Policies aimed at reducing uncertainties and preserving the gains from trade and investment liberalization will be key in this new environment.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.313-316
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• 2004

BCF ·Business Collaboration Framework ·Object implementation neutral approach to the exchange of global business requirements(omitted)

• Journal of the Korean Institute of Educational Facilities
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• v.15 no.3
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• pp.52-58
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• 2008

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.439-446
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• 2013

The market taxonomy approach may lead to the most effective strategy to promote the export of Korean Railway Systems. By prioritizing opportunities in the global marketplace and subsequently identifying market segments, this approach will reveal the most effective market strategies for Korean rail exporters. This study suggests the market potential index. In addition, it also introduces how market segmentation should be done for the global rail supply market. Applying the market taxonomy to derive strategic implications, this study portrays several export projects currently being undertaken by the Korean rail industry.