• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.885-888
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• 2000

Electroantennogram(EAG) can be applied to detect odorants since insects have highly specialized olfactory receptors inside their antennae. The characteristics of EAG parameters were investigated for the quantitative measurement of a general odorant using ammonia as a model odorant. The antennae of male silkworm moth, Bombyx mori, were used for the EAG. The electical signal curves generated from a pair of antennae originating from the same silkworm moth were never identical; however, they exhibited a typical type I or type II characteristic curve pattern for every pair of antennae. The correlation between the EAG parameters and the ammonia concentration was analyzed for the type I and type II antennae. The stability of each parameter was also investigated for each type of antenna. The results show the possibility of the quantitative measurement of general odorants using the EAG technique.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.183-184
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• 2006

The simulation on the mechanism of terahertz NSOM(near-field scanning optical microscopy) have been investigated. Based on experimental results, we have demonstrated the antenna effects on the coupling between a metal tip and substrate for an emission-type terahertz NSOM. It has been found that the lateral resolution can be estimated by a simplified model using an infinitesimal dipole in the substrate.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1243-1251
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• 2007

In this paper a study on the simplified observability analysis of GPS/INS is introduced. Errors for the position, velocity, attitude, gyro and accelerometer biases, and lever arm between GPS antenna and inertial sensors are considered in the observablity analysis. From the error dynamics model in which relatively small terms are neglected, simple observability conditions are obtained such that the observability of GPS/INS is determined by the test on the attutude, gyro bias, and lever arm. Unobservable errors for the position, velocity, and accelerometer bias are determined by those for the attitude, gyro bias, and lever arm. The simplified observability conditions are applied to a constant speed horizontal motion. It is shown that there are seven unobservable modes for the motion including the vertical component of gyro bias. The analytic observability analysis results are confirmed with a covariance simulation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.407-414
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• 2002

The knowledge of interaction of electromagnetic waves in composite structures is important for designing the shielding structure for antenna such as radome. Recently, radomes are constructed in the form of foam core sandwich structures that have many mechanical advantages such as high strength, long fatigue life, low density and adaptability to the intended function of structure. However, the propagation of electromagnetic waves is affected by high anisotropic permeability and loss tangent of the composite skin. In this study, the analytical model to understand the propagation of electromagnetic waves in the anisotropic composites and foam core sandwich structures with composite skins was proposed. Numerical analyses of unidirectional composites and foam core sandwich structure as a function of incident angle were performed. From the results of analysis, the general tendencies of transmittance of electromagnetic wave through composites and foam core sandwich structure were obtained.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.41-45
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• 2006

To get accurate positions of GPS antennas, one should apply phase center variations (PCV) corrections in the data processing. Until recently, relative calibrations, originally proposed by National Geodetic Survey of United States, were the international standard. However, in late 2006, International GNSS Service will switch to absolute calibration methods. In this study, we compared the position differences caused by different PCV models, and their effects on the calculations of Precipitable Water Vapor (PWV) in the atmosphere. Data from ${\sim}40$ permanent GPS stations in Korea were processed and we found that the vertical position differences reach up to 5 cm, depending on the model selected. Also the PWV values varied quite significantly: the maximum bias in the computed PWV values was ${\sim}4$ mm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4C
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• pp.336-341
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• 2008

In this paper, beamforming algorithm is proposed which can obtain diversity gain in beamforming system that deploy antenna elements with half-wavelength. The proposed algorithm provides beam-pattern using eigen-vectors that span received signal subspace. The criterion to decide optimal rank of eigen-space used for beamforming is also proposed. A beamforming system applied the proposed algorithm shows better performance with diversity gain as getting larger angle spread. This paper provides a description of proposed algorithm with analysis of the performance using various computer simulations.

• Transactions of the Society of Information Storage Systems
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• v.11 no.2
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• pp.26-30
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• 2015

Recently, military vehicles are driven with a lot of electronic devices such as radar, antenna, and information storage devices. However, the military vehicles can be exposed to impact easily. Therefore, they have to be designed robustly in order to ensure the stability of the vehicle and the electronic devices. To achieve that, the dynamic behaviors of the military vehicle should be exactly identified. Therefore, in this research, dynamic behaviors of the vehicles were identified by carrying out road tests and we constructed finite element model to analyze the dynamic characteristics of the vehicle.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1806-1808
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• 2003

본 논문은 모의GIS(내에서 부분방전(partial discharge:PD) 발생 시 방사되는 전자파 신호를 두 개의 UHF(Ultra-High Frequency)타임 혼형안테나(Time-Do main Antennas: NBS-200)를 설계제작하여 오실로스코프를 이용한 부분방전의 위치검출에 관해 연구하였다. 실험조건은 GIS내에 금속 파티클을 넣고 전압을 32[kV]로 고정하여 파티클의 활발한 진동시에 방사되는 전자파 신호를 오실로스코프를 사용하여 측정된 두 신호의 시간차를 이용하여 추정하였다.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.176-188
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• 2002

This paper presents results of continuous wave and swept frequency response measurements over the frequency range of UNII lower and middle bands from 5.15GHz to 5.35GHz in indoor environments. From the continuous wave measurements at 5.2GHz, the excess path loss, and the statistical characteristics of the temporal and spatial fading were found. By sweeping the frequency over the band, envelope correlation as a function of frequency was found and the coherence bandwidth (CBW) was determined from the envelope correlation. Using a channel model, the CBW was used to evaluate RMS delay spread. The dependence of CBW on the antenna polarization was simulated and compared with the measurement results. The influence of room size and separation of transmitter and receiver for LOS paths on RMS delay spread was discussed.

• Journal of the Korean institute of surface engineering
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• v.45 no.4
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• pp.174-180
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• 2012

Low pressure inductively coupled plasma characteristics of argon and oxygen are numerically simulated for a 400 mm rectangular type system with a plasma fluid model. The results showed lower power absorption profile at the corner than a circular one in a 13.56 MHz driven 1.5 turn antenna system with a drift-diffusion and quasi-neutrality assumption. Ions controlled by electric field are more non-uniform than metastables and the power absorption profile of oxygen plasma is affected by horizontal gas flow pattern to show 25% lower power absorption at the pumping flange side. Oxygen negative ions which are generated in electron collisional dissociation of oxygen molecules was calculated as 0.1% of oxygen atoms with similar spatial profile.