• The Journal of Engineering Geology
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• v.26 no.2
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• pp.169-175
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• 2016

Estimations of regional stress are demonstrated in this paper. Firstly, regional stress is defined and the characteristics of regional stress are then discussed based on the local stresses measured by the Compact Conical-ended Borehole Overcoring (CCBO) technique and the results from the earthquake focal mechanism. Secondly, the regional stresses are estimated by a back analysis of three-dimensional finite element models, using the local stresses measured by the CCBO and hydraulic fracturing.

• Journal of Digital Convergence
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• v.1 no.1
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• pp.213-234
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• 2003

"Trust" becomes a focal issue in e-business. Unlike traditional business environment, virtual situation requires new trust-ensuring mechanism other than face-to-face meetings and other related means of confirmation. Many countries are trying to foster trust services industry in order to increase e-business transactions and activities. This paper compares and contrasts these countries' policies on trust services. Conclusions of this comparative research includes: (1) trust services industry will be tightly integrated horizontally and increase their scope vertically towards trust in business sense over and beyond the mere technical level trust, (2) necessity of reciprocal trust authentication exchange is calling for an international standard in a near future, and (3) two different types of policies are under development: government-led and industry-led. Advantages and disadvantages of different approaches are presented with details of legal implications and structures of operations.

• The Korean Journal of Pain
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• v.25 no.2
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• pp.75-80
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• 2012

Hypnosis is an altered state of consciousness that comprises of heightened absorption in focal attention, dissociation of peripheral awareness, and enhanced responsiveness to social cues. Hypnosis has a long tradition of effectiveness in controlling somatic symptoms, such as pain. Pain, the most common symptom in clinical practice, is a multi-dimensional experience, which includes sensory-discriminative, affective-emotional, cognitive and behavioral components. There is a growing recognition for hypnosis and related techniques in pain management. Psychological approaches to pain control, such as hypnosis, can be highly effective analgesics, but are underused in Korea. In this article, we would like to review the basic concepts of hypnosis, the mechanism, and the outcome data of the analgesic effects of hypnosis, and also, its limitations.

• The Korean Journal of Pain
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• v.24 no.1
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• pp.57-60
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• 2011

Pulsed radiofrequency (PRF) treatment of nervous tissue has been proposed as a less neurodestructive technique alternative to continuous RF heat lesioning. Recently, clinical reports using PRF have shown favorable effects in the treatment of a variety of focal pain areas, even in non-nervous tissues; however, the mechanism of effect underlying this treatment to non-nervous tissue remains unclear. We report the case of a 67-year-old male who presented with pain reliving point in the posterior neck. The patient had pain in the posterior neck for 3 years. The pain subsided with pressure applied to a point in the posterior neck. There were no specific abnormal findings on laboratory testing and radiologic examinations. After PRF treatment to the pain-relieving point, he had pain relief which lasted more than 5 months.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.6
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• pp.637-642
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• 2002

An arc-shaped line array slit has been used for the laser generation of focused Lamb waves. The spatially expanded Nd:YAG pulse laser was illuminated through the arc-shaped line array slit on the surface of a sample plate to generate the Lamb waves of the same pattern as the slit. Then the generated Lamb waves were focused at the focal point of which distance from the slit position is dependent on the curvature of slit arc. The proposed method showed better spatial resolution than the conventional linear array slit in the detection of laser machined linear defect and drill machined circular defect on aluminum plates of 2mm thickness. Using the focused waves, we could detect the linear defect and the circular defect with the improvement of spatial resolution. The method can also be combined with the scanning mechanism to get an image just like by the scanning acoustic microscope(SAM).

• Korean Journal of Metals and Materials
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• v.50 no.3
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• pp.233-236
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• 2012

ZnO nanowires were fabricated through thermal evaporation of Zn or ZnS powder using solar energy. The Zn or ZnS powder was heated and evaporated by sunlight. The sunlight was concentrated on the Zn or ZnS powder by a converging lens and then the Zn or ZnS powder was evaporated and oxidized in air. After oxidation, ZnO nanowires were fabricated in the focal point. Strong ultraviolet emission, which corresponds to the near band-edge emission, was observed from the ZnO nanowires synthesized using Zn powder as a source material. Meanwhile, green emission, related to intrinsic defects such as oxygen vacancies, prevailed for the ZnO nanowires fabricated using ZnS powder. No catalysts were used in the fabrication of the ZnO nanowires, which suggested the ZnO nanowires were grown by a vapor-solid mechanism.

• Nutrition Research and Practice
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• v.14 no.2
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• pp.127-133
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• 2020

BACKGROUND/OBJECTIVES: Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells. MATERIALS/METHODS: Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action. RESULTS: Administration with up to 40 μM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20-40 μM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels. CONCLUSIONS: Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.392-392
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• 2011

Carbon nanotubes (CNT) emitter has widely become an attractive mechanism that draws growing interests for cold cathode field emission.$^{1,2}$ CNT yarns have demonstrated its potential as excellent field emitters.$^3$ Extensive simulations were carried out in designing a CNT yarn-based cathode assembly. The focal spot size dependence on the anode surface of the geometric parameters such as axial distance of the electrostatic focus lens from the cathode and the applied bias voltages at the cathode, grid mesh and electrostatic focus lens were studied. The detailed computer simulations using Opera 3D electromagnetic software$^4$ had revealed that a remarkable size of focal spot under a focusing lens triode type set-up design was achieved. The result of this optimization simulation would then be applied for the construction of the CNT yarn based micro-focus x-ray tube with its field emission characteristics evaluated.

• The Journal of Internal Korean Medicine
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• v.24 no.2
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• pp.181-189
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• 2003

The goal of this study is to investigate whether Uncariae Ramulus et Uncus can protect nerve cells against ischemic neuronal damage is caused by middle cerebral artery occlusion (MCAO) in rats' brains and to investigate whether the neuroprotective effect of Uncariae Ramulus et Uncus is concerned with IEGs(immediate early genes) expression. Uncariae Ramulus et Uncus(l00mg/kg) was administered immediately after 2 hours of MCAO and maintained for 7 days. On 7th days after 2 hours of MCAO, the brains of rats were sliced through the hippocampus. c-Fos immunohistochemistry stain and Cresyl violet stain were done for microscopic examination. Each number of viable neurons and c-Fos immunoreactive cells in CA1 was counted. The density of neurons and c-Fos immunoreactive cells were significantly decreased in MCAO-operated ischemic rats compared to that sham-operated rats. Administration of Uncariae Ramulus et Uncus group significantly elevated MCAO-induced decrease in density of neurons, and elevated MCAO-induced decrease in c-Fos immunoreactive cells. These results suggest that the neuroprotective effect of Uncariae Ramulus et Uncus against focal cerebral ischemia. Also, we hypothesized that neuroprotective mechanism of Uncariae Ramulus et Uncus is related to IEGs expression.

• The Journal of Engineering Geology
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• v.19 no.4
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• pp.509-515
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• 2009

Three earthquakes with local magnitude ($M_L$) greater than 3.0 occurred on April 24, June 2 and September 12 in 1999 nearby the Gyeongju area. Redetermined epicenters were located within the radius of 1 km. We carried out waveform inversion analysis to estimate focal mechanism of June 2 event, and P and S wave polarity and their amplitude ratio analysis to estimate focal mechanisms of April 24 and September 12 events. June 2 and September 12 events had similar fault plane solutions each other. The fault plane solution of April 24 event included those of other 2 events, but its distribution range was relatively broad. Focal mechanisms of those events had a strike slip faulting with a small normal component. P-axes of those events were ENE-WSW which were similar to previous studies on the P-axis of the Korean Peninsula. Considering distances between epicenters, similarities of seismic waves and sameness of polarities of seismic data recorded at common seismic stations, these events might occurred at the same fault. The seismic moment of June 2 event was estimated to be $3.9\;{\times}\;10^{14}\;N{\cdot}m$ and this value corresponded to the moment magnitude ($M_W$) 3.7. The moment magnitude estimated by spectral analysis was 3.8, which was similar to that estimated by waveform inversion analysis. The average stress drop was estimated to be 7.5 MPa. Moment magnitudes of April 24 and September 12 events were estimated to be 3.2 and 3.4 by comparing the spectrum of those events recorded at common single seismic station.