• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.66-66
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• 2012

We describe the space project of Ultra-Fast Flash Observatory (UFFO), which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast-response rotatable mirror system which redirects opitical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in June 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We describe the science and the mission of the UFFO project, including a serious version called UFFO-100 which will be launched in 2014. With our program of ultra-fast optical response GRB observatories, we aim to gain a deeper understanding of GRB mechanisms, and potentially open up the z>10 universe to study via GRB as point source emission probes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.59-69
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• 2007

In this paper, we propose a MIMO-OFDMA (Multi Input Multi Output-Orthogonal Frequency Division Multiple Access) system based on Grassmannian beamforming for performance improvement of downlink real-time traffic transmission in harsh channel conditions with low CIR (Carrier-to-Interference Ratio). In the proposed system to reduce feedback information for the beamforming, we also apply Grassmannian Beamforming. Furthermore, we propose antenna selection scheme which performs the beamforming with more useful transmit antennas. In the proposed system, the optimal combination of transmit antennas with maximum MRT (Maximum Ratio Transmission) beamforming gain, is selected. Simulation results reveal that the proposed MIMO-OFDMA system achieves significant improvement of spectral efficiency in low CIR region as compared to a typical open-loop MIMO-OFDMA system using pseudo-orthogonal space time block code.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1571-1574
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• 2003

A shared compliant control scheme based on IMC is proposed for the position-force force reflecting control system. The controller of the slave manipulator is designed by IMC method for the open loop unstable plant. The compliant control is implemented by first order low pass filter. In the proposed scheme, the slave manipulator well tracks the position of the master manipulator in free space and the compliance of the slave manipulator is autonomously controlled in contact condition. The simulation results show that the excellence of the proposed controller.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.141-143
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• 2008

Due to the demand for high-output motors in the limited space between the wheels in an electric train, self-ventilating traction motors have been used for many years. periodical disassembly maintenance is necessary to remove the small quantities of dust that enter the motor from the open-air ventilation. Reducing this burden, as well as increasing efficiency and reducing noise, would benefit the next generation of moters To address these needs, KRRI is developing a fully enclosed type traction motor, a fully enclosed type traction motor with outer fans, a high-efficiency permanent-magnet synchronous motor and a direct-drive motor(DDM) as traction motors for the next generation of trains.

• Journal of the Korean earth science society
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• v.40 no.4
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• pp.353-381
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• 2019

The general world model for homogeneous and isotropic universe has been proposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a (4+1)-dimensional space-time, and assume that the universe is spatially a 3-dimensional hypersurface embedded in the 4-dimensional space. The simultaneity for the entire universe has been specified by the global time coordinate. We define the line element as the separation between two neighboring events on the expanding universe that are distinct in space and time, as viewed in the world reference frame. The information that determines the kinematics of the geometry of the universe such as size and expansion rate has been included in the new metric. The Einstein's field equations with the new metric imply that closed, flat, and open universes are filled with positive, zero, and negative energy, respectively. The curvature of the universe is determined by the sign of mean energy density. We have demonstrated that the flat universe is empty and stationary, equivalent to the Minkowski space-time, and that the universe with positive energy density is always spatially closed and finite. In the closed universe, the proper time of a comoving observer does not elapse uniformly as judged in the world reference frame, in which both cosmic expansion and time-varying light speeds cannot exceed the limiting speed of the special relativity. We have also reconstructed cosmic evolution histories of the closed world models that are consistent with recent astronomical observations, and derived useful formulas such as energy-momentum relation of particles, redshift, total energy in the universe, cosmic distance and time scales, and so forth. The notable feature of the spatially closed universe is that the universe started from a non-singular point in the sense that physical quantities have finite values at the initial time as judged in the world reference frame. It has also been shown that the inflation with positive acceleration at the earliest epoch is improbable.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.557-564
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• 2012

This paper presents UGV localization using multi-sensor fusion based on federated filter in outdoor environments. The conventional GPS/INS integrated system does not guarantee the robustness of localization because GPS is vulnerable to external disturbances. In many environments, however, vision system is very efficient because there are many features compared to the open space and these features can provide much information for UGV localization. Thus, this paper uses the scene matching and pose estimation based vision navigation, magnetic compass and odometer to cope with the GPS-denied environments. NR-mode federated filter is used for system safety. The experiment results with a predefined path demonstrate enhancement of the robustness and accuracy of localization in outdoor environments.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.651-656
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• 2017

In this study, we designed the system that helps drivers check all information about parking space at the entrance and find out whether the places is available or not, because the system has 'Image recognition function' which can even recognize car number plates exactly. Besides, we place the webcam close to the car number plate, so that car number can be identified more quickly. Finally, since we set the webcam high, the system keeps us from parking wrong places by displaying on the screen.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.171-178
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• 2009

In this paper, RFID (Radio Frequency Identification) based management system is introduced to control effectively logistic supply items and machinery spare parts in a ship. To apply an RFID system under very harsh environment in a ship which is a steel-structured small area with lots of compartment, we measured reading distances and angles in open space, in an steel compartment, and an real ship separately in order to investigate the reliability between various tags and RFID.

• Korean Journal of Environment and Ecology
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• v.17 no.3
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• pp.258-267
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• 2003

The purpose of this study is to present improvement devices of urban center's green function in the Public Open Space Attached Building(P.O.S.) in Incheon, Korea. Study sites were the P.O.S. of office building(10 place), transportation facility building(3 places), government office building(2 places) that were made up 1994∼2002 and analyzed establishment, using and planting status. And P.O.S.'s planting area structure of Osaka and Kawasaki in Japan that is operating P.O.S. system similar to Korea was compared with study sites of Incheon. P.O.S. of Incheon is not managing as valuable urban center's green and establishing to satisfy legal requirement. The strengthening devices of P.O.S. function are as follows. First, it is desirable that planting area rate of P.O.S. in order to develop small park in urban center is increasing by 40% that is children's park level. Second, it must be conferred about planting basis, tree selection and planting method etc. of P.O.S. with green and park development department at building authorization. Third, by the 'landscape planting standard of plottage' that is becoming planting standard of P.O.S is heightened and must increase quality and amount of green. Fourth, it is required mandatory establishing of sign so that citizens can search easily and utilize of P.O.S. Fifth, legal regulation should be decided to prevent that P.O.S. is used unlike purpose originally.

• Journal of Korea Technology Innovation Society
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• v.17 no.2
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• pp.309-333
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• 2014

To meet the challenge of new type of innovation activities requires us to understand the social context of innovation and the potential needs of innovation users and, based on this, to co-construct technology and society simultaneously. Effective 'demand articulation' activities such as the understanding and utilization of user experiences and socio-technical planning are prerequisites for carrying out post-catch up innovations shaping new trajectories and contributing to solving social problems. Living Lab has recently been emerging particularly in Europe as an 'user-driven innovation model', in which users are active participants in innovation activities. The purpose of this study is to contribute to a theoretical discussion of Living Lab as an user-driven innovation model, to make a brief review of cases of Living Lab and to explore Living Lab's applicability in the Korean context. Living Lab is an open innovation model, in which end suers actively participate in innovation processes in a particular geographical space or region and would be able to solve specific problems of that space or region. In that sense, Living Lab would be able to strengthen the problem-solving capabilities of local communities and to become a pioneer in inducing and realizing a new socio-technical system. Furthermore, Living Lab could become an innovative policy tool reflecting recent major changes in innovation policy paradigms such as post-catch up innovation, demand-oriented innovation, regional innovation, societal innovation, innovation eco-system and socio-technical system transition, and thus make a contribution to exploring a new way of bringing about changes in the Korean society.