• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.698-703
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• 2006

This paper proposes an approach to search for the odor source using an autonomous mobile robot equipped with vision and odor sensors. The robot is initially navigating around the specific area with vision system until it looks for an object in the camera image. The robot approaches the object found in the field of view and checks it with the odor sensors if it is releasing odor. If so, the odor is classified and localized with the classification algorithm based on neural network The AMOR(Autonomous Mobile Olfactory Robot) was built up and used for the experiments. Experimental results on the classification and localization of odor sources show the validity of the proposed algorithm.

• Progress in Superconductivity
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• v.4 no.1
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• pp.19-26
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• 2002

We have earlier developed a 40-channel SQUID system. An important figure of merit of a MEG system is the localization error, within which the underlying current source can be localized. With this system, we investigated the localization error in terms of the standard deviation of the coordinates of the ECDs and the systematic error due to inadequate modeling. To do this, we made localization of single current dipoles from tangential components of auditory evoked fields. Equivalent current dipoles (ECD) at N1m peak were estimated based on a locally fitted spherical conductor model. In addition, we made skull phantom and simulation measurements to investigate the contribution of various errors to the localization error. It was found that the background noise was the main source of the errors that could explain the observed standard deviation. Further, the amount of systematic error, when modeling the head with a spherical conductor, was much less than the standard deviation due to the background noise. We also demonstrated the performance of the system by measuring the evoked fields to grammatical violation in sentence comprehension.

• The Journal of the Acoustical Society of Korea
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• v.21 no.4E
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• pp.156-163
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• Wind and Structures
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• v.10 no.4
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• pp.315-346
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• 2007

A preceding companion article introduced the slot jet approach for large-scale quasi-steady modelling of a downburst outflow. This article extends the approach to model the time-dependent features of the outflow. A two-dimensional slot jet with an actuated gate produces a gust with a dominant roll vortex. Two designs for the gate mechanism are investigated. Hot-wire anemometry velocity histories and profiles are presented. As well, a three-dimensional, subcloud numerical model is used to approximate the downdraft microphysics, and to compute stationary and translating outflows at high resolution. The evolution of the horizontal and vertical velocity components is examined. Comparison of the present experimental and numerical results with field observations is encouraging.

• Journal of Welding and Joining
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• v.21 no.4
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• pp.63-68
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• 2003

Scanning electron microscopy (SEM) has been used as a surface measurement instrument and a tool for lithography in semiconductor process due to its high density localized beam. For those purposes, however, the maximum current of SEM Is less than 100pA, which is not enough fo material processing. In this paper SEM was modified to increase the amount of current reaching a specimen from gun part where current is generated, the possibility of applying SEM to material processing, especially microjoining, was investigated. The maximum current of SEM after modifications was measured up to 10$\mu$A, which is about 10$^{5}$ times greater than before modifications. Through experiments such as eutectic solder wetting on thin 304 stainless steel foil and microjoining of 10$\mu$m thick 304 stainless steel, the intensity of electron beam of SEM proved to be great enough fur material processing as heat source. And a tight jig system was found necessary to hold materials close enough fur successful microloining.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.270-277
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• 1991

A mutational alteration in the signal sequence of ribose-binding protein (RBP) of Escherichia coli, rbsB103, completely blocks the export of the protein to the periplasm. Intragenic suppressors for this mutation have been selected on minimal medium with ribose as a sole carbon source. Six suppressor mutations were characterized in detail and were found to have single amino acid wubstitution in the mature portion of RBP, which resulted in the mobility shift of the proteins on SDS polyacrylamide gel. Amino acid changes of these suppressors were localized in several peptides which are packed to form the N terminal domain of typical bilobate conformation of RBP. The involvement of SecB, a molecular chaperone, was investigated in the suppression of signal sequence mutation. Translocation efficency was found to be increased by the presence of SecB for all suppressors. It is likely that the folding characteristics of RBP altered by the suppressor mutations affect the affinity of interaction between SecB and RBP.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1174-1179
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• 2009

In this paper we develop the characteristic of density on non-uniform plasma in different layer of the semiconductor with optically controlled microwave pulses. The transient response of the microwave pulses in different plasma layer has been evaluated by calculating the variation of the reflection function of dielectric microstrip lines. The lines has used under open-ended termination containing optically induced plasma region, which has illuminated a laser source. The characteristics impedances resulting from the presence of plasma are evaluated by the transmission line model. The analyzes the variation of transient response in a 0.01cm layer near the surface for frequency range from 1GHz to 128GHz. The diffusion length LD is larger than compared to the absorption depth $l/_{\alpha}l$. The variation of characteristic response in plasma layer with microwave pulses which has in deferentially localized has been evaluated analytically.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.319-326
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• 1998

Structural intensity of plates experiencing bending vibration is analytically evaluated using the modal analysis based on the assumed mode method. In the analysis, material internal loss and localized damping are considered. The power obtained by structural intensity integration over the circle containing the excitation source is compared with the power injected into plates to verify the accuracy of the presented method and; to evaluate the convergence of mode superposition. The intensity integration is carried out varying the circle radius and the integral step to investigate their effects in case of the power estimation using structural intensities. In addition, the dominant component among internal forces in the energy transfer by the bending vibration of a stiffened plate is investigated.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.27-30
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• 2007

We have been setting up experiments on propagation of shock waves generated by the pulsed laser ablation. One side of a thin metal foil is subjected to laser ablation as a shock wave is generated from a localized spot of high intensity energy source. The resulting reactive shock wave, which penetrates through the foil is reflected by an acoustic impedance which causes the metal foil to high-strain rate deform. This short time physics is captured on an ICCD camera. The focus of our research is generating reactive shock wave and high strain rate deforming of thin metal foil for accelerating micro-particles to a very high speed on the orders of several thousand meter per second. Somce innovative applications of this device will be discussed.

• Nuclear Engineering and Technology
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• v.29 no.5
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• pp.375-384
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• 1997

Relative power density distributions of the Kori Unit 1 pressurized water reactor are calculated by Monte Carlo modeling with the MCNP code. The Kori Unit 1 core is modeled on a three-dimensional representation of the one-eighth of the reactor in-vessel component with reflective boundaries at 0 and 45 degrees. The axial core model is based on half core symmetry and is divided into four axial segments. Fission reaction density in each rod is calculated by following 100 cycles with 5,000 test neutrons in each cycle after starling with a localized neutron source and ten noncontributing settle cycles. Relative assembly power distributions are calculated from fission reaction densities of rods in assembly. After 100 cycle calculations, the system converges to a k value of 1.00039 $\geq$ 0.00084. Relative assembly power distribution is nearly the same with that of the Kori Unit 1 FSAR. Applicability of the full-scope Monte Carlo simulation in the power distribution calculation is examined by the relative root moan square error of 2.159%.