• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.181-191
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• 2007

The gemological charateristics of Gwangdong tektites and Baikdusan obsidians were investigated, using microscopy, density and refractive index measurements, X-ray fluorescence spectrometry, Inductively Coupled Plasma Mass spectrometry, X-ray powder diffraction, and electron microprobe analysis. The Gwangdong tektites and Baikdusan obsidians are both black in colour and slightly trans-lucent with various shades of brown when cut into a few mm thick. Both the materials yield conchoidal fracture on broken surface. The tektites occur as tear-drop shapes, ranging from 4 to 10 cm long, and in spheres, from 3 to 5 cm in diameter. On the surface numerous shallow pits up to 3 mm in diameter are present. Mohs' hardness and specific gravity are 5 to 5.5 and 2.66, respectively. The tektites are singly refractive, with an refractive index of 1.51. Numerous spherical air bubbles are randomly scattered throughout the tektites, and silica-rich glass inclusions are occasionally seen. X-ray powder diffraction analysis verifies that they are non-crystalline. The Baikdusan obsidians show very similar properties to those of the Gwangdong tektites, especially in hardness, amorphous nature and fracture. Nevertheless, the Baikdusan obsidian can readily be distinguished from the Gwangdong tektites by refractive index ($1.49{\sim}1.50$), specific gravity (2.67 to 2.68), and inclusions (absence of bubbles and presence of sanidine and magnetite crystals).

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.281-295
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• 2017

We determined chemical compositions like abundance of major and trace elements, Sr and Nd isotope compositions for two tektites from the Thailand and Vietnam. Their chemical compositions are similar to each other, and seem to be similar to those of PAAS (Post Archean Australian Shale) rather than upper continental crust. In particular, primitive mantle-normalized spider diagrams and chondrite-normalized REE patterns for two tektites are the same, suggesting that they might be derived from the same source material. The $^{87}Sr/^{86}Sr$ and $^{143}Nd/^{144}Nd$ ratios from Thailand tektite are $0.718870{\pm}0.000008(2{\sigma}_m)$ and $0.512024{\pm}0.000012(2{\sigma}_m)$, respectively, and those from Vietnam are $0.717022{\pm}0.000008(2{\sigma}_m)$ and $0.511986{\pm}0.000013(2{\sigma}_m)$, respectively. The $^{87}Sr/^{86}Sr$ and $^{143}Nd/^{144}Nd$ ratios from Thailand tektite are slightly enriched than those of Vietnam tektite. $^{87}Sr/^{86}Sr$ ratios from the Vietnam and Thai tektites were plotted on the range of Australasian tektites reported previously. $^{143}Nd/^{144}Nd$ ratio of Vietnam tektite from this study was lower than the range of $^{143}Nd/^{144}Nd$ ratio from the Australasian tektite reported previously whereas that of Thai tektite was included in the range of $^{143}Nd/^{144}Nd$ ratio from the Australasian tektite. The geochemical characteristics from two tektites in this study indicate that they may be derived from the very similar source materials.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1560-1571
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• 2006

The purpose of this study is to analyze relations between digital characteristics and formative features of fashion design in digital era, to find out the best way to make desirable clothes in the future affected by digital characteristics. The methods of this study are documentary research of previous studies and case study. For the study of formative features of fashion design, 100 kinds of pictures have been selected from photographs in fashion magazines, professional books and internet sites. In the theoretical study, digital characteristics are limitless repetition, compressibility, interactivity, ease of deformation and mobility. And formative features of digital design are plasticity & geometry, assemblage, joints & connections, transparency and deformation. The results of analysis are as follow. Formative features of fashion design in digital era are classified nonlinearity, variability and hybrid. There are organic relations between digital characteristics and formative features of fashion design as well as between digital characteristics and formative features of digital design. Also, there is significant similarity between formative features of digital design and formative features of fashion design in digital era.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.225-229
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• 1998

The purpose of the current study was comparative analysis of autonomic and electrocortical responses to passive and active touch of the tektites with different subjective emotional preference. Perspective goal of the project is development of a template for classification of tactile stimuli according to subjective comfort and associated physiological manifestations. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and B10PAC 100 systems with AcqKnowledge III software. Frontal, parietal and occipital EEG (relative power spectrum /percents/ of EEG bands - delta, theta, slow and fast alpha, low and fast beta), and autonomic variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, rise time and number of SCRs) were analyzed for rest baseline and stimulation conditions. Analysis of the overall pattern of reaction indicated that autonomic response to tactile stimulation was manifested in a form of moderate HR acceleration, RSP increase, RSA decrease (lowered vagal tone), decreased n and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand) were featured by short-term alpha-blocking, slightly reduced theta and significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome. Nevertheless, development of sufficiently sensitive .and reliable template for classification of emotional responses to tactile stimulation based on physiological response pattern may require more extensive empirical database.