• Title/Summary/Keyword: Intra-subject Variability

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Experimental Investigation on the Transmission of Seat Vibration to the Head for Korean-Seated Postures (한국인 앉은 자세에 대한 의자 진동의 머리 전달에 관한 실험적 연구)

  • 박용화;정완섭
    • Journal of KSNVE
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    • v.11 no.1
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    • pp.76-81
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    • 2001
  • This paper addresses experimental results carried out to investigate the transmission of seat vibration to the head for Korean. Vertical seat vibration in the frequency range of 0.5-30 Hz was applied to a seated Korean male subject. To examine the intra-variable effects on transmissibility, five different postures and three different vibration excitation levels were considered. The applied acceleration and head accelerations of the seated subject were measured simultaneously by using a 6-axes bite-bar. Detailed experimental results of measured transmissibilities are illustrated for each posture and/or vibration excitation level, and they were compared to an International Standard. They are found to allow the identification of dynamic characteristics of Korean seated body for various reat vibration environments. Furthermore, they are expected to be very useful in designing new seats for automotive and railway vehicles and in improving their vibration ride quality.

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Experimental Investigation on the Characteristics of Dynamic Masses of Korean-Seated Postures (한국인의 앉은 자세에 대한 동적 질량의 실험적 연구)

  • 박용화;정완섭
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.1017-1021
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    • 2000
  • This paper addresses experimental results carried out to investigate the characteristics of dynamic mass for Korean. Vertical seat vibration in the frequency range of 0.5-30 Hz was applied to a seated Korean male subject. To examine the intra-variable effects on dynamic mass, five different postures and three different vibration excitation levels were considered. The applied acceleration and transmitted force to the hip of the seated subject were measured simultaneously. Detailed experimental results of measured dynamic mass are illustrated for each posture and/or vibration excitation level. Maximum peaks of around 5 Hz were observed for most experimental cases. They are found to allow the identification of dynamic characteristics of Korean seated body for various real vibration environments. Furthermore, they are expected to be very useful in designing new seats for automotive and railway vehicles and in improving their vibration ride duality.

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Visual Presentation of Connected Speech Test (CST)

  • Jeong, Ok-Ran;Lee, Sang-Heun;Cho, Tae-Hwan
    • Speech Sciences
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    • v.3
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    • pp.26-37
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    • 1998
  • The Connected Speech Test (CST) was developed to test hearing aid performance using realistic stimuli (Connected speech) presented in a background of noise with a visible speaker. The CST has not been investigated as a measure of speech reading ability using the visual portion of the CST only. Thirty subjects were administered the 48 test lists of the CST using visual presentation mode only. Statistically significant differences were found between the 48 test lists and between the 12 passages of the CST (48 passages divided into 12 groups of 4 lists which were averaged.). No significant differences were found between male and female subjects; however, in all but one case, females scored better than males. No significant differences were found between students in communication disorders and students in other departments. Intra- and inter-subject variability across test lists and passages was high. Suggestions for further research include changing the scoring of the CST to be more contextually based and changing the speaker for the CST.

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A Method for Observation of Benign, Premalignant and Malignant Changes in Clinical Skin Tissue Samples via FT -IR Microspectroscopy

  • Skrebova, Natalja;Aizawa, Katsuo;Ozaki, Yukihiro;Arase, Seiji
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.457-459
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    • 2002
  • Sunlight causes various types of adverse skin changes on the sun-exposed areas of the skin, in which the most hazardous one is the induction of malignant skin tumours. FT -IR spectra were obtained from specimens excised from normal skin, BCCs, SCCs, MMs, nevi, lesions of solar keratosis and Bowen's disease. Tissue samples from freshly frozen specimens were cut into 2 sections in strictly sequential order to be stained with H & E for histopathological analysis, and then to be air-dried on CaF$_2$ slide glasses for further spectral data acquisition from defined area of interest. Intra- and inter-sample variations were estimated within grouped lesion categories according to each skin component. Mean spectra for each type of tissue pathology in the 800-1800 $cm^{-1}$ / region was interpreted using the classical group frequency approach that showed the most visible differences in spectra of benign, premalignant and malignant changes directly related to protein conformation and nucleic acid bases. The relative intensity of the nucleic acid peak was increased with progression to malignancy. In addition, PCA was able to evaluate and maximise the differences in the spectra by reducing the number of variables characterizing each patient and pathology category. This type of approach to non-destructively estimate the complexity of IR-spectra of inhomogeneous samples such as skin demonstrates the advantage of FT -IR microspectroscopy to be able to observe diseased states (benign, premalignant, malignant) and distinguish them from normal against a huge background of inter- and intra-subject variability.

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