• 전자공학회논문지A
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• 제31A권8호
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• pp.34-45
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• 1994

We studied threshold voltages and I-V characteristics. considering short channel effect of the fully depleted thin film n-channel SOI MOSFET. We presented a charge sharing model when the back surface of short channel shows accumulation depletion and inversion state respectively. A degree of charge sharing can be compared according to each of back-surface conditions. Mobility is not assumed as constant and besides bulk mobility both the mobility defined by acoustic phonon scattering and the mobility by surface roughness scattering are taken into consideration. I-V characteristics is then implemented by the mobility including vertical and parallel electric field. kThe validity of the model is proved with the 2-dimensional device simulation (MEDICI) and experimental results. The threshold voltage and charge sharing region controlled by source or drain reduced with increasing back gate voltage. The mobility is dependent upon scattering effect and electric field. so it has a strong influence on I-V characteristics.

• 한국측량학회지
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• 제35권5호
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• pp.365-374
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• 2017

SAR (Synthetic Aperture Radar) is an effective tool for monitoring areas damaged by disasters. Full PolSAR (Polarimetric SAR) enhances SAR's capabilities by providing specific scattering mechanisms. Thus, full PolSAR data have been widely used to analyze the situation when disasters occur. To interpret full PolSAR data, model-based decomposition methods are frequently used due to its easy physical interpretation of PolSAR data and computational efficiency. However, these methods present problems. One of the key problems is the overestimation of the volume scattering component. To minimize the volume scattering component, the OA (Orientation Angle) compensation method is widely utilized. This paper shows that the effect of the OA compensation was analyzed over landslide affected areas. In this paper, the OA compensation is applied by using the OA estimated from the maximum relative Hellinger distance. We conducted an experiment using two full polarimetric ALOS/PALSAR (Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar)-2 data collected over Mocoa, Colombia which was seriously damaged by the 2017 Mocoa landslide. After OA compensation, the experimental results showed volume scattering power decreased, while the double-bounce and surface scattering power increased. Particularly, significant changes were noted in urban areas. In addition, after OA compensation, the separability of the double-bounce and surface scattering components are improved over the damaged building areas. Furthermore, changes in the OA can discriminate visually between the damaged building areas and undamaged areas. In conclusion, we demonstrated that the effect of OA compensation improved the influence of the double-bounce and surface scattering components, and OA changes can be useful for detecting damaged building areas.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3043-3047
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• 2012

To investigate the scattering layer effect of a $TiO_2$ multilayer in dye-sensitized solar cells (DSSCs), we designed a new DSSC system, assembled with a CdS-$TiO_2$ scattering layer electrode. A high-magnification SEM image exhibited hollyhock-like particles with a width of 1.5-2.0 ${\mu}m$ that were aggregated into 10-nm clumps in a hexagonal petal shape. The efficiency was higher in the DSSC assembled with a CdS-$TiO_2$ scattering layer than in the DSSC assembled with $TiO_2$-only layers, due to the decreased resistance in electrochemical impedance spectroscopy (EIS). The short-circuit current density ($J_{sc}$) was increased by approximately 7.26% and the open-circuit voltage ($V_{oc}$) by 2.44% over the 1.0 wt % CdS-$TiO_2$ composite scattering layer and the incident photon-to-current conversion efficiency (IPCE) in the maximum peak was also enhanced by about 5.0%, compared to the DSSC assembled without the CdS-$TiO_2$scattering layer.

• 한국음향학회지
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• 제38권5호
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• pp.511-521
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• 2019

본 연구에서는 무한 유체에 놓여있는 유한 길이의 탄성 원통 쉘에 외부에서 비스듬히 평면파가 입사할 때 발생하는 음향 산란 현상을 이론적으로 연구했다. 유한 길이의 원통 쉘에서는 해석적인 산란 해가 존재하지 않기 때문에, Kirchhoff 가정을 적용한 Ye의 산란 기법[Z. Ye, J. Acoust. Soc. Am. 102, 877-884 (1997)]을 사용했다. 탄성 원통 쉘의 특성은 3차원 탄성파 이론을 적용하여 구현했으며 원통 쉘 내부의 유체를 고려했다. 유도된 해석 해를 이용하여 내부 유체가 산란 음장에 미치는 효과, Rayleigh 변수에 대한 산란 음장, 탄성 재질의 변화에 따른 먼 거리 산란 함수를 살펴보았다.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.1006-1009
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• 2017

We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the ${\alpha}-{\alpha}$ system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the ${\alpha}-{\alpha}$ and ${\alpha}-n$ systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

• Journal of electromagnetic engineering and science
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• 제10권2호
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• pp.61-66
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• 2010

This paper is concerned with an analysis of the back scattering of electromagnetic waves from a target moving along random rough surfaces such as the desert, and sea. First, the discrete ray tracing method(DRTM) is introduced, and then, this method is applied to the back scattering problem in order to investigate the effect of the back scattering from random rough surfaces on the electric field intensities. Finally, numerical examples of various height deviations of the Gaussian type of rough surfaces are shown. It is numerically demonstrated that the back scattering is dominated by the diffractions related to the reflections from the random rough surfaces.

• 소음진동
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• 제8권6호
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• pp.1172-1180
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• 1998

음향학적으로 강성인 물체와 연성인 물체로부터의 탄성파의 산란과 음향파의 산란을 수치적으로 해석하고 그 특성들을 비교하였다. 부분파들과. 또한 부분파들의 합인 전체 산란파의 위상 및 크기의 거동을 수치적으로 분석하고 토의하였다. 탄성파의 산란시 발생하는 종파와 횡파 사이의 모드변환 현상이 산란파의 크기와 위상에 주는 영향을 밝혔다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.979-982
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• 2007

The effect of a scattering wall surfaces on sound diffusion can be assessed by determining the scattering and diffusion coefficients in the laboratory. However, the sound field in a concert hall including scattered reflections is different from the laboratory measurement condition. Therefore, there is a need for objective investigation of diffusion in real sound fields. In this paper, possible acoustical parameters of in-situ measurements are discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1785-1788
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• 2007

We investigated the effect on light extraction in OLED by introducing aluminum micro bump light scattering reflector. By attaching the micro bump reflector to a both side emission OLED, we found that the light extraction was 1.7 times larger than a simple flat reflector. We fabricated a 20.8” inch WXGA full color AM-OLED by integrating the micro bump scattering reflector.

• Bulletin of the Korean Chemical Society
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• 제16권2호
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• pp.96-101
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• 1995

The optical properties of individual 3-to 14-micron diameter CdS crystalline spheres embedded in poly(methyl methacrylate) were studied using elastic scattering. The presence of well defined sharp peaks in the 550 to 600 nm elastic scattering spectra confirmed that each microcrystal acts as an optical cavity with cavity quality factors exceeding 104. Such natural resonator microcrystals should lead to greatly enhanced local field effects near the surface of CdS, quantum electrodynamic modification of optical transition rates of nearby species and altered photochemistry. Absorptive heating following high intensity laser irradiation was found to induce a transient washout of the high Q modes.