• Bulletin of the Korean Chemical Society
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• 제20권6호
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• pp.705-711
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• 1999

The laser-induced transient grating method is applied to study the dynamics of the nematic MBBA film. The nanosecond laser pulses of 355 nm are used to make the transient grating and the cw He-Ne laser of 633 nm is used to probe the dynamics. Strong multiple order diffractions are observed at high nematic temperatures. The reordering process induced by the phototransformed state, which is the locally melted state from the nematic sample, is attributed to the main origin of the multiple order diffractions from the nematic MBBA. The characteristics of the multiple order gratings are discussed with the grating profiles simulated from the multiple diffraction signals.

• Journal of Korean Neurosurgical Society
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• 제47권1호
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• pp.36-41
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• 2010

Objective: The aim of this study was to investigate the morphological characteristics of the thalamoperforating arteries that arise from the P1 segment of the posterior cerebral artery. Methods: Thalamoperforating arteries located in the interpeduncular fossa were dissected in 26 formalin-fixed human cadaver brains. We investigated the origin site of thalamoperforating arteries from the P1 segment, number and diameter. and variations in their origin. Results: Thalamoperforating arteries arose from the superior, posterior or posterosuperior surfaces of the P1 segment at the mean 1.93 mm (range, 0.41-4.71 mm) distance from the basilar apex and entered the brain through the posterior perforated substance. The average number was 3.6 (range 1-8) and mean diameter was 0.70 mm (range 0.24-1.18 mm). Thalamoperforating arteries could be classified into five different types according to their origin at the P1 segment: Type I (bilateral multiple), 38.5%; Type II (unilateral single, unilateral multiple), 26.9%; Type III (bilateral single), 19.2%; Type IV (unilateral single), 11.5%; Type V (unilateral multiple), 3.8%. In 15.4% of all specimens. thalamoperforating arteries arose from the only one side of P1 segment and were not noted in the other side. In such cases, the branches arising from the one side of P1 segment supplied the opposite side. Conclusion: Variations in the origin of the thalamoperforating arteries should be keep in mind to perform the surgical clipping, endovascular treatment or operation involving the interpeduncular fossa. In particular, unilateral single branch seems to be very risky and significant for surgical technique or endovascular treatment.

• 유통과학연구
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• 제11권7호
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• pp.47-56
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• 2013

Purpose - In the academic literature, the researches on a comparative study on purchase behaviors of the consumers from emerging and mature markets remain limited. Therefore, this empirical study is attempted to examine the effects of country of origin (COO), brand image and corporate image on the purchase behavior of Chinese consumers (as from emerging market) and Korean consumers (as from mature market). Research Design, data, methodology - In total, 615 valid questionnaires were collected from the main cities of China and Korea respectively, and a multiple group analysis was conducted to test the hypotheses with SPSS 16.0 and AMOS18.0. Results - Chinese consumers are not influenced by country-of-origin effect, whereas Korean consumers are sensitive to it. Both Chinese and Korean consumers are sensitive to brand image, whereas corporate image does appear to influence Chinese consumers but not Korean consumers. The effects of country-of-origin are not more influential in less developed market (China) than more developed market (Korea). Conclusions - According to the results of this empirical study, the country-of-origin effect does impact Korean consumers but not Chinese consumers' purchase behavior. Therefore, multinational companies are relatively free to make the decision, if Chinese consumers are the marketing targets, when choosing manufacturing sites.

• 한국학교보건학회지
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• 제31권3호
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• pp.146-156
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• 2018

Purpose: The purpose of this study was to compare the factors related to violence victimization between multicultural and Korean-origin adolescents. Methods: This study used the data of the 2017 Korea Youth Risk Behavior Web-Based Survey. A total of 54,748 multicultral and Korean-origin adolescents were included in the analysis. Weighted percentage and means were used to describe the sample. Simple and multiple logistic regressions were conducted using SAS 9.2. Results: The multicultural adolescents experienced more violence victimization than Korean-origin adolescents. In both groups, middle school students, habitual drug users, and those not living with their family showed a greater risk of becoming a victim of violence. In Korean-origin adolescents, while girls and those with mid-level family economic status showed a lower risk, those who had experienced sadness or despair, suicidal ideation, smoking and problematic drinking showed a higher risk of becoming a violence victim. In multicultural adolescents, those with a lower subjective health status and a lower stress level had a higher risk of violence victimization. Conclusion: Results of this study suggest that the factors significantly related to violence victimization differ between multicultural and Korean-origin adolescents. Therefore, different approaches are required for the prevention and management of violence victimization in different populations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.654-654
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• 2013

One of the most important yet unresolved problems in molecular electronics is the controversy over the number and nature of multiple conductance peaks in single-molecule junctions. Currently, there are three competing explanations of this observation: (1) manifestation of different molecule-electrode contact geometries, (2) formation of gauche defects within the molecular core, (3) involvement of different electrode surface orientations [1]. However, the exact origin of multiple conductance peaks is not yet fully understood, which indicates our incomplete understanding of the scientifically as well as techno-logically important organic-metal contacts. To theoretically resolve this problem, we previously applied a multiscale computational approach that combines force fields molecular dynamics (FF MD), density functional theory (DFT), and matrix Green's function (MGF) calculations [2] to a thermally fluctuating haxanedithiol (C6DT) molecule stretched between flat Au(111) electrodes, but could observe only a single conductance peak [3]. In this presentation, using DFT geometry optimizations and MGF calculations, we consider molecular junctions with more realistic molecule-metal contact conformations and Au(111) electrode surface directions. We also conduct DFT-based molecular dynamics for the highly stretched junction models to confirm our conclusion. We conclude that the S-Au coordination number should be the more dominant factor than the electrode surface orientation.

• 천문학회보
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• 제42권1호
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• pp.49.1-49.1
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• 2017

In order to investigate the origin of multiple stellar populations in the halo and bulge of the Milky Way, we have constructed chemical evolution models for the low-mass proto-Galactic subsystems such as globular clusters (GCs). Unlike previous studies, we assume that supernova blast waves undergo blowout without expelling the pre-enriched gas, while relatively slow winds of massive stars, together with the winds and ejecta from low and intermediate mass asymptotic giant branch stars, are all locally retained in these less massive systems. We first applied these models to investigate the origin of super-helium-rich red clump stars in the metal-rich bulge as recently suggested by Lee et al. (2015). We find that chemical enrichments by the winds of massive stars can naturally reproduce the required helium enhancement (dY/dZ = 6) for the second generation stars. Disruption of these "building blocks" in a hierarchical merging paradigm would have provided helium enhanced stars to the bulge field. Interestingly, we also find that the observed Na-O anticorrelation in metal-poor GCs can be reproduced, when multiple episodes of starbursts are allowed to continue in these subsystems. Specific star formation history with decreasing time intervals between the stellar generations, however, is required to obtain this result, as would be expected from the orbital evolution of these subsystems in a proto-Galaxy. The "mass budget problem" is also much alleviated by our models without ad-hoc assumptions on star formation efficiency and initial mass function.

• 천문학회지
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• 제40권4호
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• pp.141-145
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• 2007

Here we analyze if the ionized shells associated with giant HII regions represent the progenitors of the larger neutral hydrogen supershells detected in the Milky Way and other spiral and dwarf irregular galaxies. We calculate the evolutionary tracks that 12 HII shells found by Relano et al. (2005, 2007) would have if they expanded into the interstellar medium because of multiple supernovae explosions occurring inside the cavity. We find, contrary to Relano et al. (2007), that the evolutionary tracks of these HII shells are inconsistent with the observed parameters of the largest and most massive neutral hydrogen supershells. Thus, an additional energy source to the multiple supernovae explosions is required in order to explain the origin of the most massive neutral hydrogen shells.

• 천문학회보
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• 제41권1호
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• pp.79.2-79.2
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• 2016

The presence of multiple stellar populations is now well established in most globular clusters (GCs) in the Milky Way. The origin of this, however, is yet to be understood. In this respect, the study of NGC 2808, a GC which hosts five sub-populations differing only in light-element abundances, would help to understand the origin of this multiple stellar populations. In order to investigate CN, CH, and Ca abundances among different populations in NGC 2808, we have performed low-resolution spectroscopy for the red giant branch (RGB) stars in this GC. Here we report preliminary results from this spectroscopic analysis.

• 한국의류학회지
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• 제24권5호
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• pp.663-674
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• 2000

The purpose of this study was (1) to examine the preference for apparel brands and country of origin, (2) to evaluate the brand equity for domestic and imported apparels as perceived by Korean and American consumers, and (3) to analyze the effects of country of origin and brand equity on consumers' apparel purchase behavior. The sample included 151 Korean and 114 American consumers. The data were collected from respondents by using the mall-intercept method. In addition, the path analysis based on multiple regression analysis was applied to analyze the data. The major findings in this study were as followings; (1) Both of all Korean and US consumers preferred domestic apparel brands to imported brands but the latter preferred apparels made in home country to the former comparatively, (2) Korean consumers evaluated more favorably the brand equity for imported apparels than that for domestic apparels, but American consumers were quite the reverse, (3) To Korean consumers, the direct variable to influence the purchase intention of apparels was the perceived quality and indirect variables were the brand equity and country of origin. On the other hand, to American consumers, the perceived quality and the brand equity for domestics apparel had directly influence on the purchase intention and the brand equity for imported apparels did indirectly. Finally, implications for managerial and marketing strategies were discussed in regard to building an international apparel brand equity and improving exports with high quality apparels.

• 대한두경부종양학회지
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• 제29권2호
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• pp.71-74
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• 2013

Neck mass is a common manifestation from head and neck malignancy, most of which come from mucosal squamous cell carcinomas in the upper aero-digestive tract. However, once aspiration cytology suggests atypical malignant cells in the neck mass rather than metastatic squamous cell carcinomas, it is confusing to decide the adequate diagnostic work-ups and treatment planning. Here, we report a 29-year-old woman presenting with a growing neck mass mimicking malignancy of unknown origin, which was finally diagnosed as primary lymphoepithelial carcinoma in the parotid gland with multiple metastases to the lymph nodes. The patient underwent comprehensive neck dissection and total parotidectomy and the adjuvant radiation treatment was given. Our report highlight that the primary salivary gland cancer should be considered as the potential tumor origin in case of malignancy of unknown origin in the head and neck region and neck mass suggestive of atypical carcinomas.