• Journal of the Korean Institute of Gas
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• v.21 no.6
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• pp.61-69
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• 2017

In case of plant accident, the most important measures that field operators, control-room operators and fire fighters must take are the escape from and going into the accident sites. These two different actions are reverse directional moving actions. By training operators and fire fighters with counter-accident path taking measurements, we can prevent the small accidents from becoming large-scale accidents, and can take efficient measurements in case of actual plant accidents. Out of necessities of path-taking training, in this research, we developed the escape and rescue path-taking method for plant accident response training. We can calculate the escape and rescue routes from a operator or fire fighter's current location as of accident happening and provide route data which in turn can be used as the safety training scenario. We expect this path-taking method can enhance the effectiveness and reality of escape and rescue training scenarios.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.221-228
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• 2002

Thickness of concrete lining, voids at the back of lining or shotcrete are very important elements for inspecting the safety of tunnels. Therefore, the inspection of tunnel lining structure means to investigate the inner layer boundaries of the structure. For this purpose, seismic reflection survey is the most desirable method if it works in good conditions. However, the conventional seismic reflection method can not be properly used for investigating thin layers in the lining structure. In other words, to detect the inner boundaries, it is desirable for the wavelength of source to be less than the thickness of each layer and for the receiver to be capable of detecting high frequency(ultrasonic) signals. To this end, new appropriate source and receiver devices should be developed above all for the ultrasonic reflection survey. This paper deals primarily with the development of source and receiver devices which are essential parts of field measuring system. Interests are above all centered in both the radiation pattern, energy, frequency content of the source and the directional sensitivity of the receiver. With these newly devised ones, ultrasonic physical modeling has been performed on 3-D physical model composed of bakelite, water-proof and concrete, The measured seismograms showed a clear separation of wave arrivals reflected from each layer boundary. Furthermore, it is noteworthy that reflection events from the bottom of concrete below water-proof could be also observed. This result demonstrates the usefulness of the both devices that can be applied to benefit the ultrasonic reflection survey. Future research is being focus on dealing with at first an optimal configuration of source and receiver devices well coupled to tunnel wall, and further an efficient data control system of practical use.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.3
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• pp.151-161
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• 2014

3GPP LTE-Advanced (Release 10) system specifies carrier aggregation (CA) to enable high data rate on using multiple frequency bands, including the variout CA-specific deployment scenarios. Considering one of those scenarios in which the different directional sector antenna is employed by each frequency band, we propose a per-carrier cell selection scheme that can improve the average throughput of the cell-edge users by allowing each user equipment (UE) to select the frequency band of the adjacent cell. Furthermore, a distributed algorithm for inter-cell copperative scheduling in this scheme is proposed to support proportional fairness among the cells. It has been shown that the proposed scheduling algorithm for the per-carrier cell selection scheme improves the cell-edge user throughput roughly by 50% over that of the conventional scheme.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.211.1-211.1
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• 2012

The on-orbit test simulation for predicting the instrument directional responsivity was conducted by the Monte Carlo based integrated ray tracing (IRT) computation technique and analytic flux-to-signal conversion algorithms. For the on-orbit test simulation, the Sun model consists of the Lambertian scattering sphere and emitting spheroid rays, the Amon-Ra instrument is a two-channel including a broadband scanning radiometer (energy channel) and an imager with ${\pm}2^{\circ}$ FOV (visible channel). The solar radiation produced by the Sun model is directed to the instrument viewing port and traced through the dual channel optical train. The instrument model is rotated on its rotation axis and this gives a slow scan of the Sun model over the full field of view. The direction of the incident lights are fed with scanned images obtained from the visible channel instrument. The instrument responsivity was computed by the ratio of the incident radiation input to the instrument output. In the radiometric simulation, especially, measured BRDF of the 3D CPC was used for scattering effects on radiometry. With diamond turned 3D CPC inner surface, the anisotropic surface scattering model from the measured data was applied to ray tracing computation. The technical details of the on-orbit test simulation are presented together with field-of-view calibration plan.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.1001-1011
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• 2014

Smart Grid Devices could have security vulnerabilities that have legacy communication networks because of the fact that Smart Grid employs bi-directional communications and adopted a variety of communication interface. Consequently, it is required to build concrete response processes and to minimize the damage of the cyber attacks including security evaluation and certification methods. DCU is designed to collect meter data from numerous smart meter and send to utility's server so DCU installed between smart meter and utility's server. For this reason, If DCU compromised by attacker then attacker could use DCU to launching point for and attack on other devices. However, DCU's security evaluation and certification techniques do not suffice to be deployed in smart grid infrastructure. This work development DCU protection profile based on CC, it is expected that provide some assistance to DCU manufacturer for development of DCU security target and to DCU operator for help safety management of DCU.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.187-194
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• 2006

Recently satellite SAR techniques have become essential observation tools for various ocean phenomena such as wind, wave, and current. The CMOD4 and CMOD-IFR2 models are used to calculate the magnitude of wind at SAR resolution with no directional information. Combination of the wave-SAR spectrum analysis and the inter-look cross-spectra techniques provides amplitude and direction of the ocean wave over a square-km sized imagette, The Doppler shift measurement of SAR image yields surface speed of the ocean current along the rador looking direction, again at imagette resolution. In this paper we report the development of a SAR Ocean processor (SOP) incorporating all of these techniques. We have applied the SOP to several RADARSAT-1 images of the coast of Korean peninsula and compared the results with oceanographic data, which showed reliability of spaceborne SAR-based oceanographic research.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.35-42
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• 2007

Recently satellite SAR techniques have become essential observation tools for various ocean phenomena such as wind, wave, and current. The CMOD4 and CMOD-IFR2 models are used to calculate the magnitude of wind at SAR resolution with no directional information. Combination of the wave-SAR spectrum analysis and the inter-look cross-spectra techniques provides amplitude and direction of the ocean wave over a square-km sized imagette, The Doppler shift measurement of SAR image yields surface speed of the ocean current along the radar looking direction, again at imagette resolution. In this paper we report the development of a SAR Ocean processor(SOP) incorporating all of these techniques. We have applied the SOP to several RADARSAT-1 images of the coast of Korean peninsula and compared the results with oceanographic data, which showed reliability of spaceborne SAR-based oceanographic research.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2693-2700
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• 2009

This paper proposes an effective compression method to utilize the 3D integral image with large amount of data obtained by a lens array in various applications. The conventional compression methods for still images exhibit low performance in terms of coding efficiency and visual quality, since they cannot remove the correlation between elemental images. In the moving picture compression methods, 1D scanning techniques that produce a sequence of elemental images are not enough to remove the directional correlation between elemental images. The proposed method effectively sequences the elemental images from an integral image by the 2D referencing technique and compresses them using the multi-frame referencing of H.264/AVC. The proposed 2D referencing technique selects the optimal reference image according to vertical, horizontal, and diagonal correlation between elemental images. Experimental results show that compression with the sequence of elemental images presents better coding efficiency than that of still image compression. Moreover, the proposed 2D referencing technique is superior to the 1D scanning methods in terms of the objective performance and visual quality.

• The Korean Journal of Physiology
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• v.2 no.2
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• pp.75-81
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• 1968

According to recent observations of Cohen et al. the patterns of vestibular eye movements of rabbits are different from those of cats. However, the causes of such difference of the reflex eye movements in these species are not wholly explained. While the accumulated data obtained from cats appear to be established, experimental evidences in rabbits are rather meager. The author had re-examined the reflex eye movements of rabbits and attempted to find a mechanism which causes such difference in the reflex eye movements between two species. In anesthesized rabbit, unilateral individual semicircular canal nerve was stimulated selectively with a fine insulated electrode which was inserted through a hole made on the corresponding osseous canal, under a dissecting microscope. When an individual canal nerve was stimulated, the reflex movements of both eyes were observed, photographed, and recorded kymographically. Extraocular muscles were also studied to find their morphological characteristics and to correlate them with the function of the muscles. 1. At the beginning of the stimulation, both eyes moved to a specific direction depending upon the canal stimulated, and such directional eye movements were sustained during the whole course of stimulation. Amplitude of the eye movement showed graded responses to the increasing frequency of the stimulus, reaching to the maximal response at 200-300 cps. 2. Stimulation of the unilateral horizontal canal nerve caused conjugate eye movements, which was also observed in cats and other species by other investigators. 3. Stimulation of the unilateral vertical canal nerve caused a pattern of non-conjugate eye movements, which are different from those observed in cats. Such different patterns of vestibular eye movements in two different species are ascribable to the functional difference of the inferior and superior oblique muscles.

• Journal of Navigation and Port Research
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• v.37 no.6
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• pp.663-671
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• 2013

The width of Haeundae beach has been decreasing annually due to the loss of sand from land, high waves, reflected waves, etc.. The accurate prediction of wave-induced currents is indispensible to analyze the beach deformation due to the sediment transport. In the this study, Numerical experiments were performed with seasonal representative wave on the basis of a long term and comprehensive survey data. In summer, we found the deposition of Mipo by longshore current eastly by ordinary and S waves, and in winter, the deposition of Dongback-island by longshore current westly by ordinary and E waves. In addition, rip current occurs in the middle of Haeundae beach by 50 year return period wave and current westly along the coast by ESE directional wave.