• Title/Summary/Keyword: Incoherent layers

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Expressions for Ellipsometric Constants of Samples Covered with Two Thick Incoherent Films (결맞음길이보다 두꺼운 두 개의 막에 덮여있는 시료의 타원식)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
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    • v.24 no.2
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    • pp.92-98
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    • 2013
  • The expressions for ellipsometric constants of a sample covered with two thick films are derived, where incoherent superposition of multiply reflected lights inside thick films is properly considered in the frame of the rotating analyzer ellipsometry. The derived expressions are successfully applied to the analysis of a silicon wafer with a thin silicon dioxide film on it, which is placed beneath a cover glass and an air gap.

Alzheimer's disease recognition from spontaneous speech using large language models

  • Jeong-Uk Bang;Seung-Hoon Han;Byung-Ok Kang
    • ETRI Journal
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    • v.46 no.1
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    • pp.96-105
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    • 2024
  • We propose a method to automatically predict Alzheimer's disease from speech data using the ChatGPT large language model. Alzheimer's disease patients often exhibit distinctive characteristics when describing images, such as difficulties in recalling words, grammar errors, repetitive language, and incoherent narratives. For prediction, we initially employ a speech recognition system to transcribe participants' speech into text. We then gather opinions by inputting the transcribed text into ChatGPT as well as a prompt designed to solicit fluency evaluations. Subsequently, we extract embeddings from the speech, text, and opinions by the pretrained models. Finally, we use a classifier consisting of transformer blocks and linear layers to identify participants with this type of dementia. Experiments are conducted using the extensively used ADReSSo dataset. The results yield a maximum accuracy of 87.3% when speech, text, and opinions are used in conjunction. This finding suggests the potential of leveraging evaluation feedback from language models to address challenges in Alzheimer's disease recognition.

Magnetic Properties of Multilayered and Mixed $Pr_{0.65}$Ca_{0.35}MnO_3/La_{0.7}Sr_{0.3}MnO_3$ Films

  • V. G. Prokhorov;Lee, Y. P.;V. S. Flis;Park, J. S.
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.67-69
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    • 2003
  • The magnetic properties of single- and poly-crystalline $La_{0.7}Sr_{0.3}MnO_3/Pr_{0.65}Ca_{0.35}MnO_3$ multilayered (ML) films, and composite (CP) $(La_{0.7}Sr_{0.3})_{0.5}(Pr_{0.65}Ca_{0.35}_{0.5}MnO_3$ films, prepared by laser ablation, have been investigated in a wide temperature range. It was shown that the transformation from an incoherent to a coherent interface in the ML films leads to an enhancement of the ferromagnetic coupling between layers and to a single-phase magnetic transition. The amorphous CP films demonstrate a paramagnetic behavior of the magnetization with a sharp peak at $T_{G}\approx$45 K, which was interpreted as the formation of Griffiths phase. A short-term annealing at $750^{\circ}C$ induced the complete crystallization of film, and a recovery of the ferromagnetic and the metal-insulator transitions.

Radiation shielding properties of weathered soils: Influence of the chemical composition and granulometric fractions

  • Pires, Luiz F.
    • Nuclear Engineering and Technology
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    • v.54 no.9
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    • pp.3470-3477
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    • 2022
  • Soils are porous materials with high shielding capability to attenuate gamma and X-rays. The disposal of radionuclides throughout the soil profile can expose the living organisms to ionizing radiation. Thus, studies aiming to analyze the shielding properties of the soils are of particular interest for radiation shielding. Investigations on evaluating the shielding capabilities of highly weathered soils are still scarce, meaning that additional research is necessary to check their efficiency to attenuate radiation. In this study, the radiation shielding properties of contrasting soils were evaluated. The radiation interaction parameters assessed were attenuation coefficients, mean free path, and half- and tenth-value layers. At low photon energies, the photoelectric absorption contribution to the attenuation coefficient predominated, while at intermediate and high photon energies, the incoherent scattering and pair production were the dominant effects. Soils with the highest densities presented the best shielding properties, regardless of their chemical compositions. Increases in the attenuation coefficient and decreases in shielding parameters of the soils were associated with increases in clay, Fe2O3, Al2O3, and TiO2 amounts. In addition, this paper provides a comprehensive description of the shielding properties of weathered soils showing the importance of their granulometric fractions and oxides to the attenuation of the radiation.