• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.419-431
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• 2018

In this paper, we propose a novel method for monitoring mood trend of Twitter users by analyzing their daily tweets for a long period. Then, to more accurately understand their tweets, we analyze all types of content in tweets, i.e., texts and emoticons, and images, thus develop a multimodal sentiment analysis method. In the proposed method, two single-modal analyses first are performed to extract the users' moods hidden in texts and images: a lexicon-based and learning-based text classifier and a learning-based image classifier. Thereafter, the extracted moods from the respective analyses are combined into a tweet mood and aggregated a daily mood. As a result, the proposed method generates a user daily mood flow graph, which allows us for monitoring the mood trend of users more intuitively. For evaluation, we perform two sets of experiment. First, we collect the data sets of 40,447 data. We evaluate our method via comparing the state-of-the-art techniques. In our experiments, we demonstrate that the proposed multimodal analysis method outperforms other baselines and our own methods using text-based tweets or images only. Furthermore, to evaluate the potential of the proposed method in monitoring users' mood trend, we tested the proposed method with 40 depressive users and 40 normal users. It proves that the proposed method can be effectively used in finding depressed users.

• Progress in Medical Physics
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• v.10 no.3
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• pp.159-168
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• 1999

Cardiac disease is one of the leading causes of death in Korea. In quantitative analysis of cardiac function and morphological information by three-dimensional reconstruction of magnetic resonance images, left ventricle provides an important role functionally and physiologically. However, existing procedures mostly rely on the extensive human interaction and are seldom evaluated on clinical applications. In this study, we developed a system which could perform automatic extraction of enpicardial and endocardial contour and analysis of cardiac function to evaluate reliability and stability of each system comparing with the result of ARGUS system offered 1.5T Siemens MRI system and manual method performed by clinicians. For various aspects, we investigated reliability of each system by compared with left ventricular contour, end-diastolic volume (EDV), end-systolic volume (ESV), stock volume (SV), ejection fraction (EF), cardiac output (CO) and wall thickness (WT). When comparing with manual method, extracted results of developed process using minimum error threshold (MET) method that automatically extracts contour from cardiac MR images and ARGUS system were demonstrated as successful rate 90% of the contour extraction. When calculating cardiac function parameters using MET and comparing with using correlation coefficients analysis method, the process extracts endocardial and epicardial contour using MET, values from automatic and ARGUS method agreed with manual values within :t 3% average error. It was successfully demonstrated that automatic method using threshold technique could provide high potential for assessing of each parameters with relatively high reliability compared with manual method. In this study, the method developed in this study could reduce processing time compared with ARGUS and manual method due to a simple threshold technique. This method is useful for diagnosis of cardiac disease, simulating physiological function and amount of blood flow of left ventricle. In addition, this method could be valuable in developing automatic systems in order to apply to other deformable image models.

• Journal of Life Science
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• v.21 no.10
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• pp.1494-1499
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• 2011

${\beta}$-lapachone, a quinone of lapachol extracted from the bark of the lapacho tree, has been found to induce apoptosis in various human cancer cells. In the present study, we investigated further possible mechanisms by which ${\beta}$-lapachone exerts its pro-apoptotic action in cultured human lung cancer A549 cells. ${\beta}$-lapachone treatment resulted in inhibition of growth and induction of apoptosis in a concentration-dependent manner, as determined by MTT assay and flow cytometry analysis. The induction of apoptosis by ${\beta}$-lapachone was associated with up-regulation of the expression of p53 and p21 in both transcriptional and translational levels, and the phosphorylation of p53. In addition, ${\beta}$-lapachone activated caspase-3 and -9, and induced degradation of caspase-3 target proteins such as poly (ADP-ribose) polymerase (PARP) and ${\beta}$-catenin. Furthermore, ${\beta}$-lapachone treatment caused a progressive decrease in the expression levels of cyclooxygenase (COX)-2 without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E2 synthesis. Taken together, these results indicated that ${\beta}$-lapachone may have therapeutic potential in human lung cancer treatment.

• Journal of the Korean earth science society
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• v.36 no.3
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• pp.210-221
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• 2015

The terrain features and surface characteristics are the most important elements not only in meteorological modeling but also in air quality modeling. The diurnal evolution of local climate over complex terrain may be significantly controlled by the ground irregularities. Such topographic features can affect a thermally driven flow, either directly by causing changes in the wind direction or indirectly, by inducing significant variations in the ground temperature. Over a complex terrain, these variations are due to the nonuniform distribution of solar radiation, which is highly determined by the ground geometrical characteristics, i.e. slope and orientation. Therefore, the accuracy of prediction of regional scale circulation is strong associated with the accuracy of land-use and topographic information in meso-scale circulation assessment. The objective of this work is a numerical simulation using MM5-A2C model with the detailed topography and land-use information as the surface boundary conditions of the air flow field in mountain regions. Meteorological conditions estimated by MM5-A2C command a great influence on the dispersion of mountain areas with the reasonable feature of topography where there is an important difference in orographic forcing.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.7-14
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• 1995

This research was conducted to apply the QUAL2E model to be adopted to the Nam river under current water quality conditions. The survey area of total 60 Km was divided into five reaches. Each reach was then subdivided into the uniform computational elements of 1.5 Km. Based on the stream characteristics, nine sampling stations consisting of six at main streams and three at tributaries were selected. The field data were obtained from the selected stations twice during October of 1991 and May of 1992, which represented the cold weather and low flow, also the warm weather and low flow conditions, respectively. As the results of sensitivity analysis of the model, the important parameters were the rates of BOD decay, Org-N oxidation, $NH_3-N$ oxidation, Org-P decay. The calibrated and verified results by QUAL2E model were correlation coefficient of $0.45{\sim}0.94$. The results displayed a good agreement between the variables of the field measurements and the model simulations, indicating a potential use of the QUAL2E model for the water quality assessment in the Nam River.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.185-194
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• 2008

There is increased soil erosion potential at highland agricultural crop fields because of its topographic characteristics and site-specific agricultural management practices performed at these areas. The agricultural upland fields are usually located at the sloping areas, resulting in higher soil loss, pesticides, and nutrients in case of torrential rainfall events or typhoon, such as 2002 Rusa and 2003 MaeMi. At the highland agricultural fields, the soil reconditioning have been performed every year to decrease damage by continuous cropping and pests. Also it has been done to increase crop productivity and soil fertility. The increased amounts of soil used for soil reconditioning are increasing over the years, causing significant impacts on water quality at the receiving water bodies. In this study, the field investigation was done to check soil reconditioning status for potato, carrot, and cabbage at the Doam-dam watershed. With these data obtained from the field investigation, the Soil and Water Assesment Tool (SWAT) model was used to simulate the soil loss reduction with environment-friendly and agronomically enough soil reconditioning. The average soil reconditioning depth for potato was 34.3 cm, 48.3 cm for carrot, and 31.2 cm for cabbage at the Doam-dam watershed. These data were used for SWAT model runs. Before the SWAT simulation, the SWAT ArcView GIS Patch, developed by the Kangwon National University, was applied because of proper simulation of soil erosion and sediment yield at the sloping watershed, such as the Doam-dam watershed. With this patch applied, the Coefficient of Determination ($R^2$) value was 0.85 and the Nash-Sutcliffe Model Efficiency (EI) was 0.75 for flow calibration. The $R^2$ value was 0.87 and the EI was 0.85 for flow validation. For sediment simulation, the $R^2$ value was 0.91 and the EI was 0.70, indicating the SWAT model predicts the soil erosion processes and sediment yield at the Doam-dam watershed. With the calibrated and validated SWAT for the Doam-dam watershed, the soil erosion reduction was investigated for potato, carrot, and cabbage. For potato, around 19.3 cm of soil were over applied to the agricultural field, causing 146% of more soil erosion rate, approximately 33.3 cm, causing 146% of more soil erosion for carrot, and approximately 16.2 cm, causing 44% of more soil erosion. The results obtained in this study showed that excessive soil reconditioning are performed at the highland agricultural fields, causing severe muddy water issues and water quality degradation at the Doam-water watershed. The results can be used to develop soil reconditioning standard policy for various crops at the highland agricultural fields, without causing problems agronomically and environmentally.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.1
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• pp.9-15
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• 2006

For the accurate safety assessment of potential radioactive waste disposal site which is located in the crystalline rock it is important to simulate the mass transportation through engineered and natural barrier system precisely, characterized by porous and fractured media respectively. In this work the methods to construct discrete fracture network for the analysis of flow and mass transport through fractured-porous medium are described. The probability density function is adopted in generating fracture properties for the realistic representation of real fractured rock. In order to investigate the intersection between a porous and a fractured medium described by a 2 dimensional rectangular and a cuboid grid respectively, an additional imaginary fracture is adopted at the face of a porous medium intersected by a fracture. In order to construct large scale flow paths an effective method to find interconnected fractures and algorithms of swift detecting connectivities between fractures or porous medium and fractures are proposed. These methods are expected to contribute to the development of numerical program for the simulation of radioactive nuclide transport through fractured-porous medium from radioactive waste disposal site.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.274-281
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• 2015

Thermal and nuclear power plants on shore commonly use the sea water for cooling facility. Discharged cooling water has the high kinematic energy potential due to amount of water flux. Numerical analysis was made to find the suitable combinations between the arrangement of tidal turbines and the overall dimensions of the discharged channel. Several parameters such as the turbine diameter to inlet size, and the axial distance to turbine size were investigated. Power coefficients for various test conditions were also compared to see the effect of inlet configurations such as single inlet and dual inlet. For the single inlet, the mean power coefficient appeared to be gradually decreased with increasing distance, and the maximum power was obtained when the turbine diameter was same as the inlet diameter. For the dual inlet, the tendency was similar so that the better result when the turbine diameter was same as the inlet diameter. It is expected that the present methodology can be extensively utilized to harness the high kinetic energy flow of the discharge channel of power plant.

• Journal of Life Science
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• v.30 no.5
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• pp.460-467
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• 2020

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers in the word. Although radiation and chemotherapy are generally effective, there are various side effects that greatly limit the effectiveness of these treatments. Therefore, traditional herbs may have potential as important resources for the discovery of liver cancer therapeutics. In this study, we selected three Korean herbal medicine formulas from the Donguibogam, namely Bigihwan (BGH), Daechilgithang (DCGT), and Mokwhyangbinranghwan (MHBRH), and evaluated their anti-cancer effects on HCC cells. According to our results of three ethanol extracts, BGH was more effective at suppressing HCC growth than DCGT or MHBRH. Furthermore, flow cytometry analysis showed that inhibition of HCC proliferation by the three extracts was associated with the induction of apoptosis and autophagy. In particular, BGH significantly increased mitochondrial impairment and showed the possibility of inducing mitophagy in comparison with the other two extracts. BGH prominently upregulated the levels of microtubule-associated protein light chain-3 which was accompanied by a decrease in the expression of anti-apoptotic Bcl-2 without altering the expression of pro-apoptotic Bax. In addition, the levels of PTEN-induced kinase 1 were also markedly increased in BGH-treated HCC cells. Moreover, autophagy blocking improved cell viability and reduced apoptosis after the three treatments, indicating that autophagy by these extracts enhances HCC cells against cytotoxicity. In conclusion, our findings show that BGH demonstrates the highest anti-cancer activity among the three formulas and inhibits the proliferation of HCC cells through autophagy induction.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.73-81
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• 1996

The self-diffusion coefficients of chloride and tritiated water ranged from 4.8 $\times$ 10-7 to 7.2 $\times$ 10-7 cm2/sec and 5.5 $\times$ 10-5 to 1.6 $\times$ 10-4 cm2/sec for three different depths of soil constituents at about 50% water content by volume, respectively Mobility of solute and water was conducted under steady-state flow conditions in a field soil consisting of 70 cm of clay to silty clay over a medium sand. A steady-state water flow conditions was maintained by applying irrigation water at a constant flux of 2cm per day. The water labeled with chloride and tritium was leached into the plot during the steady-state condition for 87 days. The positions of tritium and chloride as a function of soil depth and the time was measured by extracting samples of the soil solution with suction probes. Extremes in solute displacement occurred at equal and different depths within the plot. An analysis of these measurements indicated the observations of the pore-water velocity and the apparent diffusion coefficient were log normally disturbed. Twenty-four soil suction probes, used to identify the rate at which a solute was displaced in the soil, will yield an estimate of the mean pore-water velocity of this soils within a range of approximately 5% of its true value providing the effects of potential solute-soil interaction are taken into account.