• Economic and Environmental Geology
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• v.53 no.6
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• pp.703-713
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• 2020

In many geological fields, including hydrogeology, it is of great importance to determine the heterogeneity of the subsurface media. This study briefly introduces the concept and theory of the method that can estimate the hydraulic properties of the media constituting the aquifer, which was recently introduced by Park (2020). After the introduction, the method was applied to the synthetic aquifer to demonstrate the practicality, from which various implications were drawn. The introduced technique uses a global optimization technique called the covariance matrix adaptation evolution strategy (CMA-ES). Conceptually, it is a methodology to characterize the aquifer heterogeneity by assimilating the groundwater level time-series data due to the imposed hydraulic stress. As a result of applying the developed technique to estimate the hydraulic conductivity of a hypothetical aquifer, it was confirmed that a total of 40000 unknown values were estimated in an affordable computational time. In addition, the results of the estimates showed a close numerical and structural similarity to the reference hydraulic conductivity field, confirming that the quality of the estimation by the proposed method is high. In this study, the developed method was applied to a limited case, but it is expected that it can be applied to a wider variety of cases through additional development of the method. The development technique has the potential to be applied not only to the field of hydrogeology, but also to various fields of geology and geophysics. Further development of the method is currently underway.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.247-252
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• 2022

The arial parts of Artemisia argyi were extracted with methanol : water (70:30), and the concentrates was partitioned into EtOAc (ethyl acetate), n-BuOH (normal butanol), and H₂O (water) fractions. The repeated silica gel and ODS (octadecyl silica gel) column chromatographies for EtOAc and n-BuOH fractions led to isolation of four flavonoids without any ambiguity based on intensive interpretation of several spectroscopic data including nuclear magnetic resonance, and mass spectrometry. The chemical structure of the isolated compounds revealed to (2S)-naringenin (1), 3-methylkaempferol (2), 3,3'-dimethylquercetin (3), and 3,3',4'-trimethylquercetin (4). These four compounds were first isolated from A. argyi through this study. In this study, four compounds isolated from A. argyi showed an increase in glutathione mean and a decrease in glutathione heterogeneity so that the compounds uniformly raised the intracellular glutathione (GSH) level. Based on these results, it is considered that it can be used as a functional pharmacological material.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.353-366
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• 2022

Spatial estimation of geoscience data (geo-data) is challenging due to spatial heterogeneity, data scarcity, and high dimensionality. A novel spatial estimation method is needed to consider the characteristics of geo-data. In this study, we proposed the application of Gaussian Mixture Model (GMM) among machine learning algorithms with multivariate data for robust spatial predictions. The performance of the proposed approach was tested through soil chemical concentration data from a former smelting area. The concentrations of As and Pb determined by ex-situ ICP-AES were the primary variables to be interpolated, while the other metal concentrations by ICP-AES and all data determined by in-situ portable X-ray fluorescence (PXRF) were used as auxiliary variables in GMM and ordinary cokriging (OCK). Among the multidimensional auxiliary variables, important variables were selected using a variable selection method based on the random forest. The results of GMM with important multivariate auxiliary data decreased the root mean-squared error (RMSE) down to 0.11 for As and 0.33 for Pb and increased the correlations (r) up to 0.31 for As and 0.46 for Pb compared to those from ordinary kriging and OCK using univariate or bivariate data. The use of GMM improved the performance of spatial interpretation of anthropogenic metals in soil. The multivariate spatial approach can be applied to understand complex and heterogeneous geological and geochemical features.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.6
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• pp.323-341
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• 2019

Background: Local anesthetics alone or in combination with adjuncts, such as oral medications, have routinely been used for pain control during endodontic treatment. The best clinical choice amongst the vast numbers of agents and techniques available for pain control for irreversible pulpitis is unclear. This network meta-analysis combined the available evidence on agents and techniques for pulpal anesthesia in the maxilla and mandible, in order to identify the best amongst these approaches statistically, as a basis for future clinical trials. Methods: Randomized trials in MEDLINE, DARE, and COCHRANE databases were screened based on inclusion criteria and data were extracted. Heterogeneity was assessed and odds ratios were used to estimate effects. Inconsistencies between direct and indirect pooled estimates were evaluated by H-statistics. The Grading of Recommendation, Assessment, Development, and Evaluation working group approach was used to assess evidence quality. Results: Sixty-two studies (nine studies in the maxilla and 53 studies in the mandible) were included in the meta-analysis. Increased mandibular pulpal anesthesia success was observed on premedication with aceclofenac + paracetamol or supplemental 4% articaine buccal infiltration or ibuprofen+paracetamol premedication, all the above mentioned with 2% lignocaine inferior alveolar nerve block (IANB). No significant difference was noted for any of the agents investigated in terms of the success rate of maxillary pulpal anesthesia. Conclusion: Direct and indirect comparisons indicated that some combinations of IANB with premedication and/or supplemental infiltration had a greater chance of producing successful mandibular pulpal anesthesia. No ideal technique for maxillary anesthesia emerged. Randomized clinical trials with increased sample size may be needed to provide more conclusive data. Our findings suggest that further high-quality studies are required in order to provide definitive direction to clinicians regarding the best agents and techniques to use for mandibular and maxillary anesthesia for irreversible pulpitis.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.782-800
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• 2006

Image metadata is used to describe the contents, structures, and features of a given image data. There exist lots of image metadata-related standards. Such image metadata need to be shared to efficiently search the correct images in Web Service-enabled distributed environments. In this thesis, we propose an interoperable system architecture for utilizing image metadata and query extension methods using metadata mapping for correct and efficient image searching. In the proposed methods, the provider schema using non-standard image metadata are mapped into the schema based on the VRA standard, which is used as a basic and intermediary standard in MDR(MetaData Registry). We support mapping operations between the VRA standard and other standards, to reduce the number of unnecessary mapping operations and to enable easier addition of schema based on new standards. Using the proposed query processing methods, which utilize image metadata and overcome their heterogeneity by metadata mapping, it is possible to severely improve the correctness of image retrieval. To show the usefulness of our schemes, we implemented a prototype system and performed retrieval performance evaluation on extended query processing.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.2
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• pp.127-134
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• 2009

In product development, CAD and CAE systems taking part in the design process were individually developed. Furthermore, in product development, different divisions and businesses often have heterogeneous CAD/CAE systems and methods for expressing product data, and addressing this heterogeneity creates additional costs and causes longer development periods. To ensure successful collaboration in the design process, it is therefore imperative that different CAD, CAE, and other related systems be managed in an organic and integrated manner from the initial stages of product development. Therefore, this study suggests an integrated CAD/CAE system including optimization in a more effective and integrated manner but also to support interfacing and the collective use of design and analysis tools. To validate the proposed method, a stiffened plate example is taken as an example. It is found that the proposed method could overcome the bottleneck of CAD and CAE such as transferability of data, though CATIA and ANSYS are used at the moment. Besides, carrying out an optimization process during the CAE process is another essential parts for the structural optimization process.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.156-168
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• 2013

Drilling expedition #1 in 2007 and drilling expedition #2 in 2010 were performed for gas hydrate resources evaluation and optimal site selection of pilot test in Ulleung basin, East Sea, Korea. This study presents to build the 3D spatial distribution models using the estimated sedimentary facies, porosity, and gas hydrate saturation derived by well logs and core analysis data from UBGH1-4, UBGH1-9, UBGH1-10, UBGH1-14, UBGH2-2-1, UBGH2-2-2, UBGH2-6, UBGH2-9, UBGH2-10 and UBGH2-11. The objective of 3D spatial distribution modeling is to build a geological representation of the gas hydrate-bearing sediment that honors the heterogeneity in 3D grid scale. The facies modeling is populating sedimentary facies into a geological grid using sequential indicator simulation. The porosity and gas hydrate saturation modeling used sequential Gaussian simulation to populate properties stochastically into grid cells.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.277-287
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• 2020

The study examines the impact of international integration on Vietnam's rural and urban income inequalities using the regression model. The data used for this study is based on the results of the Vietnam Household Living Standards survey from 2008 to 2016 of the General Statistics Office. These surveys conducted nationwide with a sample size of 46,995 households in 3,133 communes/wards which were representative at national, regional, urban, rural and provincial levels. The level of international economic integration used in the study is the proportion of import and export turnover of GDP, the proportion of FDI and GDP by province. Due to the heterogeneity and unobservableness of the single observant in the data set, we selected the models of random and fixed effects. The research results show that during the economic integration process, the Export/GDP factor is negatively related to income inequality. The remaining factors (GDP per capita, FDI/GDP, Educational level of households, Percentage of internet users, Aggregation of foreign cash inflow and GDP of the province) are all positively related to income inequality. The findings help assess the impact of international integration on rural-urban income inequality, but also provides a concrete basis to help policymakers address income inequality in the integration process.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7613-7619
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• 2013

Background and Aims: Helicobacter pylori infection may be associated with an increased risk of colorectal carcinoma. However, as most studies on this subject were relatively small in size and differed at least partially in their designs, their results remain controversial. In this study, we aimed to carry out a meta-analysis to evaluate the potential association of H. pylori infection with colorectal adenoma and adenocarcinoma risk, covering all of the different testing methods. Methods: We conducted a search in PubMed, Medline, EBSCO, High Wire Press, OVID, and EMBASE covering all published papers up to March 2013. According to the established inclusion criteria, essential data were then extracted from the included studies and further analyzed by a systematic meta-analysis. Odds ratios were employed to evaluate the relationship between H. pylori infection and the risk of colorectal neoplasms. Results: Twenty-two studies were included, and the odds ratio for the association between H. pylori infection and colorectal cancer was 1.49 (95% confidence interval 1.30-1.72). No statistically significant heterogeneity was observed. Publication bias was ruled out. Conclusion: The pooled data suggest H. pylori infection indeed increases the risk of colorectal adenoma and adenocarcinoma.

• The KIPS Transactions:PartD
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• v.18D no.2
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• pp.89-100
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• 2011

The CNV (Copy Number Variation) which is one of the genetic structural variations in human genome is closely related with the function of gene. In particular, the genome-wide association studies for genetic diseased persons have been researched. However, there have been few studies which infer the genetic function of CNV with normal human. In this paper, we propose the analysis method to reveal the functional relationship between common CNV and genes without considering their genomic loci. To achieve that, we propose the data integration method for heterogeneity biological data and novel measurement which can calculate the correlation between common CNV and genes. To verify the significance of proposed method, we has experimented several verification tests with GO database. The result showed that the novel measurement had enough significance compared with random test and the proposed method could systematically produce the candidates of genetic function which have strong correlation with common CNV.