• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.837-843
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• 1998

This paper presents the thermomechanical and fracture mechanics evaluation procedure of thermal striping damage on the secondary piping of LMFR using Green's function method and standard FEM. The thermohydraulic loading conditions used in the present analysis are simplified sinusoidal thermal loads and the random type data thermal load. The thermomechainical fatigue damage was evaluated according to ASME code subsectionNH. The analysis results of fatigue for the sinusoidal and random load cases show that fatigue failure would occur at a geometrically discontinuous location during 90,000 hours of operation The fracture mechanics analysis showed that the crack would be initiated at an early stage of the operation. The fatigue crack was evaluated to propagate up to 5 ㎜ along the thickness direction during the first 944 and 1083 hours of operation for the sinusoidal and the random loading cases, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1669-1676
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• 1993

In this paper, a thin-straight monopole antenna attached to a conducting box is analyzed using a moment method with the pocklington integral expression for the exact Green's function. A modeling of a conducting box is based on a Wire-Grid method for an efficient calculation procedure. A system of linear equation is obtained using the piecewise sinusoidal basis function. And a Junction basis function is enforcing to represent the physical current on the edge of the conducting box. Especially, the junction basis functions are overlapped for the current continuity preserving on the vertexes. Numerical results are obtained for the current distribution on the unified antenna/conducting box system, input impedance and radiation pattern. The results are compared with the known data.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.95-104
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• 2019

In this paper, we propose a method to design a generalized sinusoidal frequency modulated(GSFM) pulse that is robust to reverberation environment. GSFM pulses are a generalized form of SFM(Sinusoidal frequency modulated) pulses, which have the advantage of having a thumbtack ambiguity function with excellent range and Doppler resolution. However, the periodicity disappears during the generalization process, therefore, the detection performance is reduced in reverberation environment compared to SFM pulse with comb spectrum. In this paper, the trade-off relationship between the reverberation suppression performance of the SFM pulse and the range resolution performance of the GSFM pulse is analyzed by appropriately changing the parameter ${\rho}$ of the GSFM pulse. In order to verify the performance of the proposed GSFM pulse, the simulation was performed and it was confirmed that the proposed GSFM pulse has excellent distance resolution while detecting the slow Doppler target.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.162-169
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• 2022

We utilized Fas21, a resveratrol analog, to modulate the function of hepatic stellate cells (HSCs) and liver sinusoidal endothelial cells (LSECs) during the angiogenic phase of murine liver metastasis by B16 melanoma and 51b colorectal carcinoma. Preangiogenic micrometastases were treated with Fas21 (1 mg/kg/day) or vehicle during the development of intra-angiogenic tracts. Mice treated with Fas21 showed reduced liver tumor foci in both liver metastasis models. Micrometastases were classified immunohistochemically, as well as according to their position coordinates and connection to local microvasculature. The volume of liver occupied by sinusoidal-type foci, containing infiltrating angiogenic capillaries, decreased by ~50% in Fas21-treated mice compared to vehicle-treated ones in both tumor metastasis models. The volume of portal foci, containing peripheral neoangiogenesis within a discontinuous layer of myofibroblasts, was similar in all experimental groups in both tumor metastasis models, but displayed enhanced necrotic central areas devoid of angiogenesis following Fas21 treatment. As a result, sinusoidal tumors from mice treated with Fas21 showed a 50% reduction in desmin(+)/asma(+) HSCs and CD31(+) vessel density, and a 45% reduction in intrametastatic VEGF mRNA compared with sinusoidal tumors from vehicle-treated mice. Necrotic portal metastases increased 2-4-fold in treated mice. In vitro, Fas21 reduced VEGF secretion by HSCs and 51b cells dose-dependently. Additionally, HSCs migration in response to tumor soluble factors was dose-dependently diminished by Fas21, as was LSEC migration in response to HSCs and tumor soluble factors. Resveratrol analog Fas21 inhibits the proangiogenic response of HSCs and LSECs during the development of murine liver metastasis.

• Proceedings of the KSRS Conference
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• v.1
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• pp.142-145
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• 2006

The synergism of active and passive microwave techniques for hurricane ocean wind remote sensing is explored. We performed the analysis of Windsat data for Atlantic hurricanes in 2003-2005. The polarimetric third Stokes parameter observations from the Windsat 10, 18 and 37 GHz channels were collocated with the ocean surface winds from the Holland wind model, the NOAA HWind wind vectors and the Global Data Assimilation System (GDAS) operated by the National Center for Environmental Prediction (NCEP). The collocated data were binned as a function of wind speed and wind direction, and were expanded by sinusoidal series of the relative azimuth angles between wind and observation directions. The coefficients of the sinusoidal series, corrected for atmospheric attenuation, have been used to develop an empirical geophysical model function (GMF). The Windsat GMF for extreme high wind compares very well with the aircraft radiometer and radar measurements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.2
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• pp.149-159
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• 1988

In this paper, the Fourier Transform is employed to solve the coupled differential equations of modal power and three equations of the mode coupling coeficient are dierived using the phasor form trial soluation. The theory of the mode coupling coefficient contains a few theories proposed by earlier authers. Also it is seen that in case the optical source is modulated by a sinusoidal function, this theory is applied as well. In experiment, the mode coupling coefficient is determinded for a multimode graded-index fiber by using the optical source, which modulated by a sinusoidal function.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.805-808
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• 1999

In this paper, a chattering alleviation ISM speed controller for the sinusoidal type BIDC motor is designed. Dead Zone function is proposed to change the chattering occurring in the transient state form high frequency to low frequency and time-varying gains are applied for the control input to eliminate the steady state excessive chattering in the conventional ISM. The proposed Dead Zone function represents the sliding layer composed of two switching surfaces and if a state vector exists in this layer, the chattering don’t occur. Simulation and experimental results confirm the useful effects of the above algorithm.

• Science of Emotion and Sensibility
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• v.1 no.1
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• pp.181-197
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• 1998

전정기관은 자세의 조절에 관여하지만, 전정기관의 손상은 현기증 및 자세부조화를 초래한다. 본 연구에서는 현기증의 원인을 규명할 목적으로 전정기능을 평가할 수 있는 정현파 회전자극시스템을 개발하고자 하였다. 정현파 회전자극시스템은 회전의자와 구동 및 분석프로그램으로 구성하였으며, DC 서보모터로 구동되는 회전의자는 0.01-0.64 Hz의 주파수범위에서 60 ˚/sec의 초고속도로 정현파 회전한다. 현기증 환자에서 전정기능을 평가하기 위하여 전정안구반사, 시운동성 전정안구반사 및 시각의 억제에 의한 전정안구반사를 측정하여 안구운동의 이득, 위상, 대칭성 등을 산출하도록 정현파 회전자극시스템을 개발하였으며, 정상 성인에서 시험한 결과 신뢰성있는 성적을 얻었다. 따라서 본 시스템은 현기증 환자의 진단 및 치료정도를 판정할 수 있으르로 임상적으로 널리 사용할 수 있을 것으로 사료된다.

• The Journal of the Acoustical Society of Korea
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• v.22 no.4E
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• pp.141-149
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• 2003

As music of digital form has been widely used, many people have been interested in the automatic extraction of natural information of music itself, such as key of a music, chord progression, melody progression, tempo, etc. Although some studies have been tried, consistent and reliable results of musical information extraction had not been achieved. In this paper, we propose a method to extract chord and tempo information from general polyphonic music signals. Chord can be expressed by combination of some musical notes and those notes also consist of some frequency components individually. Thus, it is necessary to analyze the frequency components included in musical signal for the extraction of chord information. In this study, we utilize a sinusoidal modeling, which uses sinusoids corresponding to frequencies of musical tones, and show reliable chord extraction results of sinusoidal modeling. We could also find that the tempo of music, which is the one of remarkable feature of music signal, interactively supports the chord extraction idea, if used together. The proposed scheme of musical feature extraction is able to be used in many application fields, such as digital music services using queries of musical features, the operation of music database, and music players mounting chord displaying function, etc.

• Geophysics and Geophysical Exploration
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• v.17 no.2
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• pp.88-94
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• 2014

Due to mechanical failure or geographical accessibility, the seismic data can be partially missed. In addition, it can be coarsely sampled such as crossline of the marine streamer data. This seismic data that irregular sampled and spatial aliased may cause problems during seismic data processing. Accurate and efficient interpolation method can solve this problem. Futhermore, interpolation can save the acquisition cost and time by reducing the number of shots and receivers. Among various interpolation methods, the Matching Pursuit method can be applied to any sampling type which is regular or irregular. However, in case of using sinusoidal basis function, this method has a limitation in spatial aliasing. Therefore, in this study, we have developed wavelet based Matching Pursuit method that uses wavelet instead of sinusoidal function for the improvement of dealiasing performance. In addition, we have improved interpolation speed by using inner product instead of L-2 norm.