• Journal of Korean Society of Steel Construction
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• v.15 no.4 s.65
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• pp.379-388
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• 2003

The response of single story buildings and other case studies were investigated to observe trends and develop a better understanding of the impact of some design parameters on the seismic response of Concentrically Braced Frames (CBF). While many parameters are known to influence the behavior of braced frames, the focus of this study was mostly on quantifying energy dissipation in compression and its effectiveness on seismic performance. Based on dynamic analyses of single story braced frame and case studies, a bracing member designed with bigger R and larger KL/r was found to result in lower normalized cumulative energy ratio in both cases.

• The Journal of Korean Medicine
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• v.27 no.3 s.67
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• pp.201-211
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• 2006

Background: Although several efforts have been made recently to grade the severity of sublingual veins, these methods still meet some problems: clinicians' subjectivity and diversity of lighting conditions. Objectives: The purpose of our study was to quantify the severity of sublingual veins using CDs (color differences), and to verify clinical validity of the parameters of sublingual veins using CDs. Methods: We photographed the inferior surface of subjects' tongue from 74 subjects. CDs were computed through two sets of mean $L^*a^*b^*$ values extracted from BRC (black reference color) and the inferior surface of the tongue. We assumed that SVI (sublingual veins index) normalized percentage of a reciprocal of CDs between BRC and the inferior surface of the tongue including sublingual veins and BISV (black index of sublingual veins) percentage of a reciprocal of CDs between BRC and the main trunk of sublingual veins could be applied as quantitative parameters of sublingual veins and examined whether there are meaningful correlations between CDs and subjective grading by the clinicians or not. Results: There were high positive correlations of SVI and BISV to clinician evaluation respectively (r=0.715, 0.634). We computed a multiple regression equation which includes SVI and BISV as independent factors $(r^2=0.60);\;Y=0.711+0.046X_1+0.205X_2$ (Y: the severity of sublingual veins, $X_1:\;SVI,\;X_2:\;BISV$). Conclusions: We conclude that the severity of sublingual veins can be quantified through SVI and BISV, minimizing the clinicians' subjectivity and the diversity of lighting conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.6
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• pp.586-594
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• 2013

This paper proposes a new coupling element of microwave slot coupler for designing waveguide slot array which can reduce the effect of undesired higher order mode coupling between coupling and radiating slots in the branch waveguide. The proposed device is composed of a centered longitudinal shunt-series coupling slot at the center of broad wall shared by two crossed rectangular waveguides and an asymmetric compound iris that excites the coupling slot. We first have obtained scattering parameters for the proposed coupler by use of EM S/W tool HFSS and then extracted the parameters of T- network equivalent circuit for the coupling slot. We also have analyzed the resonant properties such as resonant length and normalized admittance by changing the geometrical dimensions. The measured results for the fabricated coupler with short-circuited block ${\lambda}_g/4$ away from the coupling slot are well agreed with the simulated ones.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.380-393
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• 2015

This study presents how we can evaluate stereo camera systems for the structural deformation monitoring. A stereo camera system, consisting of a set of stereo cameras and reflective markers attached on the structure, is introduced for the measurement and the stereo pattern recognition (SPR) method is utilized for the full-field structural deformation estimation. Performance of this measurement system depends on many parameters including types and specifications of the cameras, locations and orientations of them, and sizes and positions of markers; it is difficult to experimentally identify the effects of each parameter on the measurement performance. In this study, a simulation framework for evaluating performance of the stereo camera systems with various parameters has been developed. The maximum normalized root-mean-square (RMS) error is defined as a representative index of stereo camera system performance. A plate structure is chosen for an introductory example. Its several modal harmonic vibrations are generated and estimated in the simulation framework. Two cases of simulations are conducted to see the effects of camera locations and the resolutions of the cameras. An experimental validation is carried out for a few selected cases from the simulations. Using the simultaneous laser displacement sensor (LDS) measurements as the reference, the measurement errors are obtained and compared with the simulations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.93-102
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• 1991

This study aims to develop techniques for generating Digital Elevation Model(DEM) from SPOT Computer Compatible Tape(CCT) data, so as to present an effective way of generation of DEM for large area. As the first phase of extracting ground heights from SPOT stereo digital data, the bundle adjustment technique was used to determine the satellite exterior orientation parameters. Because SPOT data has the characteristics of multiple perspective projection, exterior orientation Parameters were modelled as a function of scan lines. In the second phase, a normalized cross correlation matching technique was applied to search for the conjugate pixels ill stereo pairs. The preliminary study showed that the matching window size of 13$\times$13 was adequate. After image coordinates of the conjugate pixels were determined by the matching technique, the ground coordinates of the corresponding pixels were calculated by the space intersection method. Then DEM was generated by interpolations. In addtion an algorithm for the elimination of abnormal elevation was developed and applied. The algorithm was very effective to improve the accuracy of the generated DEM.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.307-314
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• 1999

This paper describes an informatlon compression of electrically evoked myoelectric signal, M-wave. This wave shows a direct response m lato-response of nerve conductlQn study and has a characteristic with finite time support. M-wave is a useful factor for investing neurodi~ease and is often desirable to have a compact description of its shape and time evolution. The aim of this paper is to show that the AR modeling IS a effective method for compressing an information of M-wave. First, AR model parameters of real M-wave are estimated. And then. they are verified by approximatmg a M-wave using estimated AR parameters and by comparing to other melhod, Hermite tlansform[4]. To concretely evaluate the proposed method, the NMSE(normalized mean square error) of approximation curves are compared. As a result, AR modeling is effective for M-wave assessment because of its capability for the information compression.

• Journal of the Korean Chemical Society
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• v.47 no.2
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• pp.109-114
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• 2003

The electronic absorption spectra of trans-$[CrX_2([15]aneN_4)]ClO_4\;([15]aneN_4$=1,4,8,12-tetraazacyclopentadecane; X=F, Cl) complexes have been interpreted using the ligand field theory. An AOMX program is used to optimize the differences between the calculated and the observed positions for the spin-allowed transition bands. The crystal field theory(CFT) parameter is directly related to the angular overlap model(AOM), normalized spherical harmonic hamiltonians(NSH), and semiempirical parameters. The various ligand field parameters are discussed in terms of their chemical significances. According to the ligand field analysis, we can confirm that the fluoride ligand is a very strong ${\sigma}-$ and ${\pi}-$donor while the chloride has weak ${\sigma}-$ and ${\pi}-$donor properties toward chromium(III) ion.

• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.67-72
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• 2012

Finite element method was used to compare un-piled and piled raft foundation behaviors on sandy soils in this study. The soil parameters were estimated from SPT tests of 25 boreholes. Based on these soil parameters, a finite element analysis was conducted on un-piled and piled raft foundations. For the un-piled raft, the normalized settlement parameter for raft sizes of $8m{\times}8m$ and $15m{\times}15m$ ranged from 1.02~1.15 and 0.64~0.81, respectively. The raft thickness affects differential settlement and bending moments, but has little effect on load sharing or maximum settlement. Pile spacing greatly affected the maximum settlement, the differential settlement, the bending moment in the raft, and the load shared by the piles, while the differential settlement, the maximum bending moment and the load sharing are not affected very much by increasing the pile lengths.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.94-102
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• 2003

This paper describes the load parallel type full-bridge high frequency resonant inverter can be used as power source. Output control method of proposed circuit is compared with pulse frequency modulation(PFM), pulse width modulation(PWM) and pulse phase variation(Phase-Shift). The analysis of the proposed circuit is generally described by using the normalized parameters. The principle of basic operating and the its characteristics are estimated according to the parameters such as switching frequency(${\mu}$), pulse width($\theta$d) the variation of phase angle($\phi$) by three driving signal patterns. Experimental results are presented to verify the theoretical analysis result. In future, Characteristics by three driving signal control method is provided as useful data in case of output control of a power supply in various fields as induction heating application, DC-DC converter etc.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.3
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• pp.20-28
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• 2002

This paper describes the time sharing type high frequency resonant inviter can be used as power of induction heating. This closed inverter can be obtained output frequency three times than switching frequency by composing three unit inviter of conventional Half-Bridge serial resonant inverter in parallel with input power source also, this reduce switching loss because it has ZVS function. The analysis of the proposed circuit is generally described by using the normailized proposed parameters. The principle of basic operating and the its charasteristics are extimated by the parameters such as switching frequency($\mu$), the variation of Phase angle($\phi$) of Phase-shift. Experimental results are presented to verify theoretical discussion. This preposed inverter will be able to be prastically used as a power supply in various fields as induction, heating application, DC-DC converter etc.