• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.322-323
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• 2008

Multi layered thin films with ZnS/$Na_3AlF_6$/ZnS were deposited on glass substrate by thermal evaporator precess and simulated by using EMP(Essential Macleod Program). EMP is a comprehensive software package to design and analyse the optical characteristics of multi-layered thin film. ZnS and $Na_3AlF_6$ were selected as a high refractive index and low refractive index material respectively. Additionally Cu was chosen as mid reflective material. Optical properties including color effect were systematically studied. in terms of different optical thickness of low refractive index material. The optical thickness of $Na_3AlF_6$ was changed as 0.25, 0.5, 0.75 and $1.0\lambda$. The film with 0.25, 0.5, 0.75 and $1.0\lambda$. of optical thickness showed mixed color range between bluish green and red purple, yellowish green and bluish green, purple and mixed color range of green and purple respectively.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.711-717
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• 2006

In order to study gas hydrate, potential future energy resources, Korea Institute of Geoscience and Mineral Resources has conducted seismic reflection survey in the East Sea since 1997. one of evidence for presence of gas hydrate in seismic reflection data is a bottom simulating reflector (BSR). The BSR occurs at the interface between overlaying higher velocity, hydrate-bearing sediment and underlying lower velocity, free gas-bearing sediment. That is often characterized by large reflection coefficient and reflection polarity reverse to that of seafloor reflection. In order to apply depth migration to seismic reflection data. we need high performance computers and a parallelizing technique because of huge data volume and computation. Phase shift plus interpolation (PSPI) is a useful method for migration due to less computing time and computational efficiency. PSPI is intrinsically parallelizing characteristic in the frequency domain. We conducted conventional data processing for the gas hydrate data of the Ease Sea and then applied prestack depth migration using message-passing-interface PSPI (MPI_PSPI) that was parallelized by MPI local-area-multi-computer (MPI_LAM). Velocity model was made using the stack velocities after we had picked horizons on the stack image with in-house processing tool, Geobit. We could find the BSRs on the migrated stack section were about at SP 3555-4162 and two way travel time around 2,950 ms in time domain. In depth domain such BSRs appear at 6-17 km distance and 2.1 km depth from the seafloor. Since energy concentrated subsurface was well imaged we have to choose acquisition parameters suited for transmitting seismic energy to target area.

• Geophysics and Geophysical Exploration
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• v.9 no.2
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• pp.139-147
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• 2006

We had conducted a numerical modeling to investigate seismic properties of gas hydrate with field parameters acquired over the East sea in 1998. We used a 2-D staggered grid finite difference method to generate synthetic elastic seismograms for multi-channel seismic survey, OBC (Ocean Bottom Cable) survey and VCS (Vertical Cable Seismic) survey. The results of this study showed that the method using staggered grid yielded stable results and could be used to seismic imaging. We could find out the high amplitude anomaly and the phase reversal phenomenon of reflection wave at interface between the gas hydrate layer and free gas layer such a BSR (Bottom Simulating Reflector) which is the evidence for existence of gas hydrate in seismic reflection data. And we computed the reflection coefficients at the incident angles corresponding to offset distance with the synthetic seismograms. The reflection coefficients acquired from the numerical modeling were nearly consistent with the reflection coefficient computed by Shuey's equation.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.3
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• pp.95-103
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• 1993

A noise simulation software is developed to estimate crosstalk and reflection noise in multi-layer printed circuit boards having upto 20 layers and carrying signals of 100 MHz range. The simulation software can handle up to 1000 nets yielding accurate noise value associated with each net. The calculation results can be used to build optimal printed citcuit boards used in high speed computers and telecommunication equipments.

• English Language & Literature Teaching
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• v.13 no.1
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• pp.261-282
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• 2007

The purpose of this study is to investigate American traditional values and American culture in English education. The understanding of American culture in English education requires the analysis of world changes in the global age. The history of American English, the formation of American society, and the background of natural environment are described in relation to the traditional American values of the earliest settlers, such as multi-culture, individual freedom, frontier heritage in the West, equality of opportunity and wealth and material abundance. Hence the case studies of students' project presentations on the American culture in English education exemplify the reflection of American traditional values in the current American life and society. It is concluded that project-based method with regard to cultural studies in English education reveals very positive learning effects by driving students' interests and active participation through the student-centered, creative, and cooperative project presentations.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.347-351
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• 2006

A novel surface plasmon resonance sensor, which can measure 2-dimensional array of immobilized ligands without using imaging devices such as CCD, has been proposed. Regular surface plasmon resonance can be directly used due to the insertion of additional layers with different thickness, on which each ligands are immobilized. Surface plasmon resonance signals are separated depending on the thickness of additional layers. The possibility of multi-sensing capability of the proposed surface plasmon resonance sensor has been verified by the modeling that is based on Fresnel reflection model.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.351-359
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• 2006

We investigated subsurface structures of the Bransfield Basin, the Antarctic with AUH (Autonomous Underwater Hydrophne) which was designed to record abyssal T-waves generated from submarine earthquakes. The data obtained from a multi-channel seismic survey and an AUH were used for this study. A seismic reflection method was applied to the multi-channel seismic survey data in order to identify bathymetry and sedimentary structures, and the signals recorded in the AUH were used to obtain deep structures as we applied a seismic refraction method. Even though we couldn’t investigate deeper and detailed structure in study area because of lack of Airgun’s capacity, the AUH showed possibilities for being used for a marine seismic survey. From this experiment, we decided the upper and lower sediment layer velocities, detected irregular basement topography probably caused by submarine volcanic/magmatic activities, and retrieved the velocity of the basement and the depth of the sediment layer/basement boundary.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.163-171
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• 2006

To evaluate inelastic seismic responses of multi-span-bridge, the equivalent single-degree-of-freedom (ESDOF) methods and the lateral load distributions are applied to the capacity spectrum method(CSM). From the pushover analysis results using the four ESDOF methods and the six types lateral load distributions, the ESDOF method more than lateral load distribution is found to have an important influence upon the pushover analysis. The effects of the higher mode on the bridge seismic behaviors are also increased as the number of pier increase. Therefore, it can be concluded that lateral load distributions and ESDOF methods for reflection of higher mode effects should be considered in the seismic analysis of the bridge structural.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1081-1085
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• 2015

In this paper a printed pair dipole antenna with double tapered microstrip balun for wireless communications is proposed. The proposed antenna consists of a pair arm of different sizes that is branched microstrip line and microstrip line with the ground plane on opposite side of the dielectric substrate plane. The proposed antenna is matched between the ground plane to the microstrip line by double tapered microstrip balun. This antenna obtains multi-band radiation frequency band. The impedance bandwidths for a reflection coefficient of VSWR ≤ 2 are about 1.01 GHz (2.35~3.336 GHz), 1.56 GHz (4.7~6.26 GHz) and 1.15GHz (6.85~8.0[GHz]). Additionally, the measurement peak gain is about 3.6 dBi. The proposed antenna is able to support wireless communication applications.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.795-800
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• 2008

The paper presents research for the established experiment environment of multi vehicle robot, localization algorithm that is based on vehicle control, and path tracking. The established experiment environment consists of ultrasonic positioning system, vehicle robot, server and wireless module. Ultrasonic positioning system measures positioning for using ultrasonic sensor and generates many errors because of the influence of environment such as a reflection of wall. For a solution of this fact, localization algorithm is proposed to determine a location using vehicle kinematics and selection of a reliable location data. And path tracking algorithm is proposed to apply localization algorithm and LOS, finally, that algorithms are verified via simulation and experimental