• Journal of Sensor Science and Technology
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• v.11 no.1
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• pp.1-8
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• 2002

In this paper, a thermopile which is applied to wide uses of temperature measuring was fabricated and its characteristic was improved by appling SOI structure to the fabrication. We improved characteristic of the thermopile by using single crystal silicon strips that has high seebeck coefficient and dielectric isolating the silicon strips from substrate with silicon dioxide film which dramatically decrease thermal conductivity between hot and cold junction compared to a silicon strip which was fabricated by ion implantation. The thermopile consists of 17 p-type single crystal silicon strips and 17 n-types by serial connection. The result of electromotive force measuring showed very good characteristic as 130mV/K when temperature difference between the two ends of the thermopile occurs by applying light on the thermopile fabricated with silicon strips of $1600{\mu}m$ length, $40{\mu}m$ width, $1{\mu}m$ thickness.

• The Korea Journal of Herbology
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• v.23 no.1
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• pp.29-38
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• 2008

Objectives : Evodia officinalis DODE (EO), an herbal plant, has been widely used in traditional Korean medicine for the treatment of vascular diseases such as hypertension. The crude extract of EO contains phenolic compounds that are effective in protecting liver microsomes, hepatocytes, and erythrocytes against oxidative damage. But EO has been little found to have an anti-inflammatory activity. We investigated anti-inflammatory activity of EO in RAW 264.7 cells and human umbilical vein endothelial cells (HUVECs). Methods : Cytotoxic activity of EO on RAW 264.7 cells was investigated by using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The nitric oxide (NO) production was measured by Griess reagent system. And proinflammatory cytokines were measured by ELISA kit. The levels of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression were measured by flow cytometer. Results : EO decreased LPS-induced NO production in RAW 264.7 cells. The inhibitory activity of EO on LPS-induced NO release is probably associated with suppressing TNF-${\alpha}$, IL-6 and MCP-1 formation. These results indicate that EO has potential as an anti-inflammatory agent. Moreover, EO decreased TNF-${\alpha}$-induced IL-8, IL-6 production, and ICAM-1 and VCAM-1 expression in HUVECs. Conclusions : EO inhibits TNF-${\alpha}$-induced inflammation via decreasing cytokines production and adhesion molecules expression. These results indicate that EO has potential as an anti-inflammation and anti-artherosclerosis agent.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.10
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• pp.925-931
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• 2010

The paper describes a Large Eddy Simulation (LES) study of turbulent flow around a cavity. A series of three-dimensional cavities placed in a turbulent boundary layer are simulated at a Reynolds number of $1.0{\times}10^5$ by considering U and h, which represent the velocity at the top and the depth of the cavity, respectively. In order to obtain the appropriate solution for the filtered Navier-Stokes equation for incompressible flow, the computational mesh forms dense close to the wall of the cavity but relatively coarse away from the wall; this helps reduce computation cost and ensure rapid convergence. The Boussinesq hypothesis is employed in the subgrid-scale turbulence model. In order to determine the subgrid-scale turbulent viscosity, the Smagorinsky-Lilly SGS model is applied and the CFL number for time marching is set as 1.0. The results show the flow variations inside cavities of different sizes and shapes.

• Sijohaknonchong
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• v.44
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• pp.237-254
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• 2016

It is by presenting the how to read of Manhoengcheongnyu(만횡청류) in this article. Premise of how to read of Manhoengcheongnyu(만횡청류), the meaning of the lyrics is inconsequential. And yet reading, at the same time, it is a singing of drinking. Such characteristic is one that is found in reading substances and singing thereof. Premise of how to read of Manhoengcheongnyu (만횡청류), to the statement of the encounter and farewell between men and women when considering these points, 'Ijeneunmotbogedo(이제는못보게도~)' is reflected the heart of the speaker is called "do not want to parting". Speaker, want their own appearance has reached the lover through the children. Lover is the speaker can be left laughing would could spend laughing after all.

• Journal of the Semiconductor & Display Technology
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• v.7 no.1
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• pp.1-5
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• 2008

In this paper, we fabricated pressure difference type gas flow sensor using only dry etching technology by ICP-RIE(inductive coupled plasma reactive ion etching). The sensor's structure consists of a common shear stress type piezoresistive pressure sensor with an orifice fabricated in the middle of the sensor diaphragm. Generally, structure like diaphragm is fabricated by wet etching technology using TMAH, but we fabricated diaphragm by only dry etching using ICP-RIE. To equalize the thickness of diaphragm we applied insulator($SiO_2$) layer of SOI(Si/$SiO_2$/Si-sub) wafer as delay layer of dry etching. Size of fabricated diaphragm is $1000{\times}1000{\times}7\;{\mu}m^3$ and overall chip $3000{\times}3000{\times}7\;{\mu}m^3$. We measured the variation of output voltage toward the change of gas pressure to analyze characteristics of the fabricated sensor. Sensitivity of fabricated sensor was relatively high as about 1.5mV/V kPa at 1kPa full-scale. Nonlinearity was below 0.5%F.S. Over-pressure range of the fabricated sensor is 100kPa or more.

• The Korea Journal of Herbology
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• v.21 no.1
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• pp.33-42
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• 2006

Objectives : The purpose of this study was to investigate the anticancer effects of Bodusan (BDS) on SNU-1 cells, a human gastric cancer cell line. Methods : To study the cytotoxic effect of BDS on SNU-1 cells, the cells were treated with various concentrations of BDS and then cell viability was determined by XTT reduction method and trypan blue exclusion assay. The typical signs of apoptosis, was examined by western blot analysis. BDS-induced MAPK activation was also examined by Western blot for phosphorylated ERK and p38. Results : BDS reduced proliferation of SNU-1 cells in a dose-dependent manner and decreased procaspase 3 level in a dose-dependent manner and induced the clevage of PARP at concentration > 500 ${\mu}g/ml$. BDS also triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome C from mitochondria to cytosol and reducing the level of anti-apoptotic Bcl-2. BDS significantly decreased ERK phosphorylation and increased p38 phosphorylation in a dose-dependent manner. Futhermore, BDS treatment up-regulated p53 and p21waf expression in a dose-dependent manner. Conclusion : BDS-induced apoptosis is MAP kinase-dependent apoptoric pathway and arrested SNU-1 cells at the G0/G1 of cell cycle. These results suggest that BDS is potentially useful as a chemotherapeutic agent in human gastric cancer.

• Journal of Sensor Science and Technology
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• v.5 no.3
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• pp.17-24
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• 1996

In order to reduce the offset and its temperature drift by the different properties of the piezoresistors and the residual stress of the piezoresistive pressure sensor, a double Wheatstone-bridge pressure sensor was studied. Because the compensation bridge was arranged near by the pressure sensitive bridge, which have the similar offset component, reduction of the offset and its temperature drift was realized by the mathematical subtraction of the output of two bridges. It was configured the compensation of the offset and its temperature drift. By this compensation method, the offset and its temperature drift were reduced approximately 95% respectively. The sensitivity of the fabricated pressure sensor was $11.7\;mV/Vkg/cm^{-2}$ for $0.9\;kgfcm^{-2}$ full-scale pressure range.

• Journal of Science Education
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• v.43 no.2
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• pp.258-269
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• 2019

This study developed an instrument for measuring STEAM education effectiveness focused on key competencies of STEAM. This study performed literature reviews on the prior studies associated with the STEAM education and completed a pilot instrument through reflective reviews by external experts. A pilot study was administered to a total of 408 students and finalized by statistical analyses such as reliability check and exploratory factor analysis. The factors of the final instrument were identified as convergence (seven items), creativity (eleven items), challenge (five items), and care (nine items). The Cronbach' ${\alpha}$ for each construct ranged from .849 to .929 turned out to be reliable. This instrument can be utilized for measuring the effectiveness of the STEAM education on students' key competencies.

• Atmosphere
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• v.34 no.1
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• pp.69-81
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• 2024

In this paper, Annual flux variations in the Boseong Tall Tower (BTT) from 2016 to 2020 were analyzed using data from three levels (2.5 m, 60 m, and 300 m). BTT was installed in Boseong-gun, Jeollanam-do in February 2014 and continued to conduct energy exchange observations such as CO2, sensible heat, and latent heat using the eddy covariance method until March 2023. The BTT was located in a very flat and uniform paddy field, and flux observations were conducted at four levels: 2.5 m, 60 m, 140 m, and 300 m above ground. Surface energy balance was confirmed from observed data of net radiation flux, soil heat flux, sensible heat flux, and latent heat flux. Additionally, 2.5 m height surface fluxes, which are most influenced by agricultural land, were compared with data from Local Data Assimilation and Prediction System (LDAPS) of the Korea Meteorological Administration to evaluate the accuracy of LDAPS flux data. The correlation coefficient between LDAPS flux data and observed values was 0.95 or higher. Excluding summer latent heat flux data, there was a general tendency for LDAPS data to be higher than observed values. The footprint areas estimated below 60 m height mainly covered agricultural land, and flux observations at 2.5 m and 60 m heights showed typical agricultural characteristics. In contrast, the footprint estimated at 300 m height did not show agricultural characteristics, indicating that observations at this height encompassed a wide range, including mountains, sea, and roads. The analysis results of long-term flux observations can contribute to understanding the energy and carbon dioxide fluxes in agricultural fields. Furthermore, these results can be utilized as essential data for validating and improving numerical models related to such fluxes.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.209-219
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• 1997

Objectives: Anterior approach to achieve arthrodesis of the cervical spine has become a widely accepted and often-used approach since its earliest reports by Bailey and Badgley, Smith and Robinson and Cloward. However, anterior interbody fusion in the presence of the posterior instability may be complicated by the bone graft dislodgement, kyphotic defomity or nonunion. As an attemp to prevent this undesirable complication, additional methods such as skeletal traction, halo appratus or even posterior fusion has been utilized. Therefore, The cervical spine locking plate(CSLP) with the anterior intervertebral body bone grafting provide immediate cervical stabilization and widely successful in achieving fusion. Material and methods: This study analysed 14 patients who underwent a single anterior procedure and application of CSLP for the treatment of the cervical spinal disorder. Eleven patients were disc herniations and three patients were traumatic lesion. The average age of the patient was 47 years and the mean follow up periods was 20 months ranging from 13 to 27 months. Results: Ambulation was started 2nd day after the operation with the aid of the Philadelpia orthoses. Bone union was observed 13 cases on average 12 weeks after operation. The one case was nonunion with plate breakage without clinical symptom. Conclusion: Anterior fusion with CSLP are thought to be a safe and valuable method for treating cervical spine disorder.