• Geomechanics and Engineering
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• v.5 no.2
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• pp.119-142
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• 2013

Pile load tests using Osterberg cells (O-cell) were conducted on cast-in-place concrete piles founded in oil sand fill and in situ oil sand at an industrial plant site in Fort McMurray, Alberta, Canada. Interpreted pile test results show that very high pile shaft resistance (with the Bjerrum-Burland or Beta coefficient of 2.5-4.5) against oil sand could be mobilized at small relative displacements of 2-3% of shaft diameter. Finite element simulations based on linear elastic and elasto-plastic models for oil sand materials were used to analyze the pile load test measurements. Two constitutive models yield comparable top-down load versus pile head displacement curves, but very different behaviour in mobilization of pile shaft and end bearing resistances. The elasto-plastic model produces more consistent matching in both pile shaft and end bearing resistances whereas the linear elastic under- and over-predicts the shaft and end bearing resistances, respectively. The mobilization of high shaft resistance in oil sand under pile load is attributed to the very dense and interlocked structure of oil sand which results in high matrix stiffness, high friction angle, and high shear dilation.

• ETRI Journal
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• v.35 no.1
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• pp.51-57
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• 2013

In this paper, a small internal antenna for a mobile handset is presented using multiband, wideband, and high-isolation multiple-input multiple-output techniques. The proposed antenna consists of three planar inverted-F antennas (PIFAs) that operate in the global system for mobile communication (GSM900), the digital communication system (DCS), the personal communication system (PCS), the universal mobile telecommunication system (UMTS), and wireless local area network (WLAN) bands with a physical size of $40mm{\times}10mm{\times}10mm$. A resonator attached to the folded PIFA creates dual resonances, achieving a wide bandwidth of approximately 460 MHz, covering the DCS, PCS, and UMTS bands; a meander shorting line is used to improve impedance matching. Additionally, a modified neutralization link is embedded between diversity antennas to enhance isolation, which results in a 6-dB improvement in the isolation and less than 0.1 in the envelope correlation coefficient evaluated from the far-field radiation patterns. Simulation and measurements demonstrate very similar results for S-parameters and radiation patterns. Peak gains show 3.73 dBi, 3.77 dBi, 3.28 dBi, 2.15 dBi, and 5.86 dBi, and antenna efficiencies show 56.15%, 72.15%, 68.59%, 52.92%, and 82.93% for GSM900, DCS, PCS, UMTS, and WLAN bands, respectively.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.20-28
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• 2016

In this study, an efficient method of designing laminate composite radar absorbing structures (RAS) is proposed with consideration given to the structural shape so as to improve aircraft stealth performance. The calculation of the radar cross section (RCS) should be decreased to enhance the efficiency of the stochastic optimization when designing an RAS. In the proposed method, RAS are optimized to match up the input impedance of the minimal RCS, which is obtained by using physical optics and the transmission line theory. Single and double layer dielectric RAS for aircraft wings are employed as numerical examples and designed using the proposed method, RCS minimization and reflection coefficient minimization. The availability of the proposed method is assessed by comparing the similarity of the results and computation time with other design methods. According to the results, the proposed method produces the same results as the stochastic optimization, which adopts the RCS as the objective function, and can improve RAS design efficiency by reducing the number of RCS analyses.

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.397-401
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• 1997

The present research program was conducted to characterize a strain of actinomycetes producing an anti methicillin-resistant Staphylococcus aureus (MRSA) antibiotic. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among over 400 isolates, a strain (AMLK-135) producing anti-MRSA antibiotic against S. aureus TK 784 was selected. According to the morphological and physiological characteristics, the strain AMLK-135 was confirmed to belong to the genus Streptomyces. From the results of species identification with the TAXON program, the strain AMLK-135 was shown to belong to major cluster 5 (Streptomyces exfoliatus), but it had a low simple matching coefficient ($S_{SM}$ SM/) value to member organisms of major cluster 5. Percentage ($\%$) of strain further away of the strain AMLK-135 was low (1.9400) and it was placed further away than the outer-most members in major cluster 5. Therefore, the strain AMLK-135 was identified as a new species of the genus Streptomyces.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1991.10a
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• pp.68-72
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• 1991

In this study, to improve temperature stability 0.05 Pb(Sn$\_$$\frac{1}{2}$/Sb$\_$$\frac{1}{2}$/O$_3$ - 0.35PbTiO$_3$ - 0.60PbZrO$_3$ + 0.4[wt%]MnO$_2$ piezoelctric oeramics of low dielectric constant and large mechanical quality factor were manufactured with the addition of Cr$_2$O$_3$by Hot Press method. And the SAW delay line was fabricated and the propagation characteristics of SAW was investigated, and the SAW filter was fabricated on C4 added by 0.2[wt%] Cr$_2$O$_3$and its frequency characteristics was investigated. The specimen, whose propagation characteristics of surface acoustic wave were the best, was C4 added by 0.2[wt%] Cr$_2$O$_3$, and its electromechanical coupling factor(ks$^2$) was 3.11[%] and its temperature coefficient of the center frequency (C$\_$fo/) was -21.27[ppm/$^{\circ}C$]. The 31[MHz] SAW IF filter of C4 scarcely had diffraction phenomena and its group delay time was 1.4673 ${\pm}$40[ns] in the pass band, and the insertion loss was -24.419[dB] on no impedance matching.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.483-487
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• 1992

Among a few number of UV-resistant isolated form various environmental sources (10), we made a comparative physio-chemoanalytical study on one of spherical bacteria isolated from air dust, presumably Deinococcus sp. (CM strain 29) with an UV resistant bacterium, Deinococcus radiophilus ATCC 27603 as the reference strain. Our isolate of UV resistant coccus, Deinococcus sp. CM 29 and D. radiophilus ATCC 27603 showed more than 75% matching coefficient in metabolic activity of various substrates. The most predominant cellular fatty acid of both strains was palmitoleic acid (C 16 :1, cis 9), but the detail fatty acid profiles were slightly dissimilar to each other. Cell-bound arange pigment seemed to be an identical chemicals on spectrophotometric analysis. L-ornithine was detected as cell-wall amino acid in both strains. Galactose was detected as cell-wall sugar in D. radiophilus ATCC 27603, whereas glucose in Deinococcus sp. CM 29. G-C molar ratio of both strains was comparable, 63-65%.

• Journal of electromagnetic engineering and science
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• v.7 no.3
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• pp.138-146
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• 2007

In this paper, a monopole antenna of conical-cylindrical compound shape is presented. The conventional circular conical monopole antenna is modified by placing a cylinder at the top of the inverted cone. The cylindrical portion is useful in the wide band impedance matching, in adjusting the antenna gain in the horizontal direction, and in reducing the cone diameter. The dependence of the antenna performance on various geometric parameters is investigated using a commercial electromagnetic simulation software, from which an optimum design of the antenna is derived. The diameter of the circular ground plane is minimized to 115 wavelength at the lowest operating frequency. The antenna proposed in this study shows a reflection coefficient less than -10 dB and a 1${\sim}$6 dBi gain over 3${\sim}$20 GHz frequencies. The antenna shows a circular-symmetric radiation pattern in the horizontal plane and a null-free pattern in the vertical direction over the whole operating frequency range.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2487-2495
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• 2000

The acoustic characteristics of expansion chamber will be changed with the variation of inlet/outlet location due to the higher order acoustic mode in a high frequency in which the plane wave theory is not available. In this paper, the acoustic performance of reactive type expansion chamber with circular cross-section is analyzed by using the modified mode matching theory. The sensitivity analysis of four-pole parameters with respect to the location of inlet and outlet is also suggested to increase the acoustic performance. The acoustic power transmission coefficient is used as cost function, and the location of inlet and outlet is used as design variables. The steepest descent method and SUMT algorithm are used for optimization technique. Several results showed that the expansion chamber with optimally located inlet/outlet had better acoustic performance than concentric expansion chamber.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.29-40
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• 2012

A challenging research issue that has been one of growing importance to those working in human-computer interaction are to endow a machine with an emotional intelligence. Thus, emotion recognition technology plays an important role in the research area of human-computer interaction, and it allows a more natural and more human-like communication between human and computer. In this paper, we propose the multimodal emotion recognition system using face and speech to improve recognition performance. The distance measurement of the face-based emotion recognition is calculated by 2D-PCA of MCS-LBP image and nearest neighbor classifier, and also the likelihood measurement is obtained by Gaussian mixture model algorithm based on pitch and mel-frequency cepstral coefficient features in speech-based emotion recognition. The individual matching scores obtained from face and speech are combined using a weighted-summation operation, and the fused-score is utilized to classify the human emotion. Through experimental results, the proposed method exhibits improved recognition accuracy of about 11.25% to 19.75% when compared to the most uni-modal approach. From these results, we confirmed that the proposed approach achieved a significant performance improvement and the proposed method was very effective.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.99-105
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• 2018

PURPOSE: The aim of this study was to evaluate the concurrent validity and clinical usefulness of the universal plastic goniometer to measure the range of motion of the internal and external rotation of the hip joint using the three dimensional motion analysis which can analyze the joints and segment movements in the most objective and quantitative method. METHODS: Clinical and kinematic data were collected from thirty individuals using a universal plastic goniometer and a ten camera motion analysis system. Passive hip rotation range was obtained three trials for left and right hip joints using two measure methods simultaneously. RESULTS: There were significant differences between all matching measures of the two measures of internal and external rotation of the hip joint (p<.05). The relationship between the two tests for all measurements of the internal and external rotation of the hip was statistically significant with correlation coefficient form r=.87 to .96. (p<.01). CONCLUSION: Clinical measurement of the internal and external rotation of the hip using a universal plastic goniometer is effective to assess the hip condition. However, application of universal plastic goniometer requires careful attention in more accurate evaluation and research verification of the internal and external rotation of hip joint.