• Management & Information Systems Review
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• v.28 no.3
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• pp.45-68
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• 2009

The Korean government is actively pursuing an ambitious IT strategy to establish Korea as one of the leaders in the world IT market. To implement the strategy, successful technology transfer from research institutions to market should be achieved. Comprehensive literature identifies sixteen variables affecting the process and results of technology transfer. The research results in four key factors in technology transfer: Communication, Distance, Equivocality, and Motivation. Communication refers to the degree to which a medium is able to efficiently and accurately conveys task-relevant information and media while distance involves both physical and cultural proximity. Equivocality refers to the degree of concreteness of technology to be transferred while motivation involves incentives for and the recognition of the importance of technology transfer activities. Further analysis shows that there are four distinctive clusters and they show very contrasting characteristics in terms of four key factors. The careful mapping of the four clusters on the four key factors show very informative technology transfer patterns, the Technology Transfer Grid.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.197-200
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• 2015

푸아송비(poisson's ratio)는 종방향 변형률에 대한 횡방향 변형률의 비로, 우리 주위 대부분의 재료들은 양의 푸아송비를 지닌다. 그러나 재료가 특정한 격자구조를 이루도록 설계할 경우 구성물질이 양의 푸아송비를 가지더라도 거시적으로는 음의 푸아송비를 구현할 수 있으며, 이러한 극한물성물질(metamaterial)을 오그제틱 물질(auxetic material)이라고 부른다. 이전까지 오그제틱 물질을 구현하기 위한 많은 메커니즘들이 개발되고 역학적, 수치적으로 해석되어 왔다. 이 논문에서는 가장 대표적인 오그제틱 구조인 리엔트런트(re-entrant) 오그제틱 구조를 빔 구조물로 모델링하여 유한요소해석을 수행하고 주요 설계 변수인 리엔트런트 각에 따라서 푸아송비와 유효 탄성계수가 어떻게 변화하는지 확인하였다.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.79-85
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• 2011

The problem of evacuating pedestrians from a room or channel under panic conditions is of obvious importance in daily life. In recent years, several computer models have been developed to simulate pedestrian dynamics. Understanding evacuation dynamics can allow for the design of more comfortable and safe pedestrian facilities. However, these models do not take into account the type and state of mind of pedestrians. They deal with pedestrians as particles and the state of mind as a social force, which is represented by conservative and long-range interactions between individuals. In this study, I used the lattice model proposed in my previous study to explore the evacuation behavior of pedestrians with morality. In this model, three types of pedestrians are considered: adults, children, and injured people. Collisions between adults and children result in injured people. When the number of injured people continuously in contact with each other reaches a given value k, the injured people are removed from the lattice space. This situation is the same as that in which pedestrians start stepping over injured people. This behavior was interpreted as the morality of pedestrians. Simulations showed that the evacuation showed down and eventually became jammed owing to the injured people acting as "obstacles" in relation to the morality k.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.43-49
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• 2019

The wired and wireless Internet is a useful window to easily acquire various types of media data. On the other hand, the public can easily get the media data including the object to which the personal information is exposed, which is a social problem. In this paper, we propose a method to robustly detect a target object that has exposed personal information using a learning algorithm and effectively block the detected target object area. In the proposed method, only the target object containing the personal information is detected using a neural network-based learning algorithm. Then, a grid-like mosaic is created and overlapped on the target object area detected in the previous step, thereby effectively blocking the object area containing the personal information. Experimental results show that the proposed algorithm robustly detects the object area in which personal information is exposed and effectively blocks the detected area through mosaic processing. The object blocking method presented in this paper is expected to be useful in many applications related to computer vision.

• Geophysics and Geophysical Exploration
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• v.7 no.2
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• pp.148-154
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• 2004

This article reviews the development of three-dimensional (3-D) magnetotelluric (MT) modeling. The 3-D modeling of electromagnetic fields is essential in understanding the physics of MT soundings, and in implementing an inversion method to reconstruct a 3-D resistivity image. Although various numerical schemes have been developed over the last two decades, practical methods have been quite limited. However, the recent rapid improvement in computer speed and memory, as well as the advance in iterative solution algorithms for a large system of equations, makes it possible to model the MT responses of complex 3-D structures, which have been very difficult to simulate before. The use of staggered grids in finite difference method has become popular, conserving a magnetic flux and an electric current and allowing for realistic discontinuous fields. The convergence of numerical solutions has been greatly accelerated by adopting Krylov subspace methods, proper preconditioning techniques, and static divergence corrections. The vector finite-element method using edge elements is also free from the discontinuity problem, and seems a natural choice for modeling complex structures including irregular topography because its flexibility allows one to capture full geometric complexity.

• Korean Journal of Optics and Photonics
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• v.21 no.5
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• pp.181-184
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• 2010

A simple technique for a flexibly tunable and switchable dual wavelength-switchable erbium-doped fiber (EDF) laser using fiber Bragg gratings is proposed and demonstrated by using both linear cavity loss controlling and homogeneous gain broadening of the EDF. The oscillating wavelength switching is successfully realized by using the modulation of the acousto-optic modulator driven by the RF signal. The wavelength spacing and lasing wavelength of the proposed wavelength-switchable laser can also be controlled by using the bending-induced tension or compression strain. The proposed tunable dual wavelength-switchable fiber laser has a lot of advantages, such as a high extinction ratio larger than 40dB and a high tunability of ~7.2 nm/$m^{-1}$.