• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.2
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• pp.267-280
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• 1992

This paper describes a numerical analysis of the light scattering patterns of roughness profiles. This analysis was based upon the light scattering theory developed by Beckmann. In the analysis, the roughness profile was regarded as a profile whose irregularities depend on the production process and the shape of cutting tool. Generally, waviness of an actual surface seriously distorts the scattered pattern of roughness profile. In order to avoid the effects of waviness of actual surfaces, several theoretically calculated scattering patterns, instead of actual scattering patterns, were used to analyze the scattering patterns of typical engineering roughness profiles. The characteristics of the light scattering patterns for five model surfaces were studied.

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.322-328
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• 1991

We have studied a characterization method of accurate size of spherical particles by fitting experimental light scattering profile to the rigorous theoretical scattering function. An efficient software has been developed for computation of the theoretical scattering function and regression analysis. A light scattering instrument has been built and the necessary data acquisition and analysis are carried out by use of a personal computer with an emphasis on the reduction of analysis and time aiming that this study will be extended toward a development of a practical particle sizing apparatus. The performance of the instrument and the software has been evaluated with latex spheres and found to be satisfactory.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.421-426
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• 2005

Scattering center extraction schemes for radar cross section reduction of large complex targets, like warships, was developed, which are an 1-D radar image method(range profile), and a direct analysis based on an object precision method. The analysis result of partial dihedral model shows that the presented direct analysis method is more efficient than the 1-D radar image method for scattering center extraction of interested targets, in terms of radar cross section reduction design, not signal processing. In order to verify the accuracy of the direct analysis method, a scattering center analysis of an naval weapon system was carried out, and the result was coincident with that of another well-known RCS analysis program. Finally, an analysis result of RCS and its scattering center of an 120m class warship-like model presented that the direct analysis method can be an efficient and powerful tools for radar cross section reduction of large complex targets.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.148-153
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• 2007

In this paper, the evolutionary adaptive wavelet transform(EAWT) is applied to the scattering analysis of radar target. EAWT algorithm uses evolutionary programming for the time-frequency parameter extraction instead of FFT and the bisection search method used in the conventional adaptive wavelet transform(AWT). Therefore, the EAWT has a better performance than the conventional AWT. In the simulation using wire target(Airbus-like), the comparisons with the conventional AWT are presented to show the superiority of the EAWT algorithm in the analysis of scattering phenomenology. The EAWT can be effectively applied to the radar target recognition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.726-730
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• 2000

In this article, the scattering effect around a microphone is studied by using boundary element method, because it is hard to find the scattering experimentally. The scattering problem is defined by impinging an obstacle, i.e. a solid cylinder, with an incident plane wave. From this analysis, the scattering is numerically calculated by varying the microphone shape, the incident angle and the distance between microphones. It is found that the scattering effect of a microphone increases as the frequency increases and is not considerable in the low frequency region. However, it is noted that there might be the pressure distortion above 4 kHz due to the scattering in microphone measurement.

• Journal of the Semiconductor & Display Technology
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• v.9 no.4
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• pp.31-37
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• 2010

In this paper, optical deflection of laser scattering has been investigated based on Rayleigh criterion for crystalline silicon wafer in solar cell. A laser scattering mechanism is newly designed using light scattering properties in silicon wafer. Intensity distributions of laser scattering are different, depending on the incident angle of laser computed from Rayleigh criterion. In case of the incident angle satisfied with the criterion, they are asymmetric. Also, their specular reflection angle is shifted to unpredicted ones. These phenomena are in accordance with previous theories of laser scattering. The optical deflection of laser scattering is experimentally identified with the designed laser scattering mechanism. Its mathematical model is presented from the geometric relationship of laser scattering. It is shown that the optical deflection of laser scattering agree with the presented model, exclusive of grazing angles which is satisfied with Rayleigh criterion.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.41-43
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• 2003

A radar scattering model is developed based on an empirical rough surface scattering model, the radiative transfer model (RTM), a numerical simulation algorithm of radar scattering from particles, and experimental data obtained by ground-based scatterometers and SAR systems. At first, the scattering matrices of scattering particles such as a leaf, a branch, and a trunk, have been modeled using the physical optics (PO) model and the numerical full-wave analysis. Then, radar scattering from a group of mixed particles has been modeled using the RTM, which leads to a general scattering model for earth surfaces. Finally, the scattering model has been verified with the experimental data obtained by scatterometers and SAR systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1439-1444
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• 2005

A two-dimensional boundary element method was used for the scattering analysis of side-drilled hole(SDH). The far-field scattering amplitude was calculated for shear vertical(SV) wave, and their frequency and time-domain results were presented. The time-domain scattering amplitude showed the directly reflected wave from the SDH leading edge as well as the creeping wave. In an immersion, pulse-echo testing, two measurement models were introduced to predict the response from SDHs. The 2-D boundary element scattering amplitude was converted to the 3-D amplitude to be used in the measurement model. The receiver voltage was calculated fer SV wave incidence at 45$^{\circ}C$ on the 1 m diameter SDH, and the result was compared with experiment.

• Current Optics and Photonics
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• v.5 no.3
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• pp.278-288
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• 2021

We propose a characterization method for the scattering property of microspheres using spectroscopic optical coherence tomography (OCT). To prove the effectiveness of the proposed method, we prepare solutions of different concentrations using microspheres ranging from 28 to 2300 nm in diameter. Time-frequency analysis is performed on the measured interference spectrum of each solution, and the resulting spectroscopic information is converted into histograms for centroid wavelengths. The histograms present a very sensitive response to changes in the concentration and size of microspheres. We classify them into three categories according to their characteristics. When the histogram of each category is replaced with the corresponding calculated value of the scattering coefficient, each category is mapped to a different scattering-coefficient region. It is expected that the proposed method could be used to investigate the optical characteristics of a biological sample from OCT images, which would be helpful for optical diagnostic and therapeutic applications.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.7-12
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• 2011

In this paper, a laser scattering mechanism are designed to detect micro defects such as dent, scratch, pinhole, etc. Its influential parameters are experimentally selected and scattering patterns of micro defects have been analyzed for silicon wafer in solar cell. As a result of experiments, scattered lights are rather increased in wafer surface with micro defects, in comparison to no micro ones. Scattering parameters are optimally selected for obtaining robust and high quality laser scattering images of micro defects. It is shown that scattered light components are linearly increased according to the increase of micro defect sizes, and the depth of micro-defects give a large influence on optical deflection.