• Journal of the Korean Chemical Society
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• v.38 no.10
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• pp.726-733
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• 1994

Supercritical fluid extraction (SFE) followed by gas chromatographic separation and mass spectrometric (MS) detection were used in rapid analysis of polycyclic aromatic hydrocarbons (PAH's) in air particulate material extracted for 30 min with 10 ml of supercritical $N_2O$ without another sample preparation step. Two samples, urban dust in Seoul area and a certified air particulate reference material 1649 supplied by the NBS (National Bureau of Standards), were processed for the purpose of evaluating extraction and analysis methods. As a result, the quantitative recovery of PAH's in the SFE method was relatively lower than conventional organic solvent extraction methods, but reproducibility was resonable, and analysis time was reduced remarkably. The method has proved to be suitable for monitoring of PAH's in air particulate material.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.26-32
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• 2008

This research presents a simulation for the fuel economy of parallel diesel hybrid vehicle. Diesel engines compared to gasoline engines have the advantages of higher fuel economy and lower $CO_2$ emission. One of the most ways to meet future fuel economy and emissions regulation is to combine diesel engine technology with a hybrid electric vehicle. The simulation of HEV is growing need for rapid analysis of the many configurations and component options. WAVE, a one-dimensional engine analysis tool, was used to a 2.7L diesel engine. ADVISOR, designed for rapid analysis of the performance and fuel economy of vehicle models, was used to conventional and hybrid electric vehicle by the use of output file from WAVE as the input engine data file for ADVISOR. A parallel diesel HEV is at least $19.7{\sim}36%$ higher fuel economy and improved acceleration ability compared to a conventional diesel vehicle. The energy loss of the parallel diesel HEV is $23{\sim}38%$ less than the conventional vehicle using regeneration.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1133-1138
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• 2014

Ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI- MS/MS) provides a high-speed method to screen a large number of samples for small molecules with specific properties. In this study, UPLC-ESI-MS/MS with multiple reaction monitoring (MRM) was employed to screen urinary phospholipid (PL) content for biomarkers of prostate cancer. From lists of urinary PLs structurally identified using nanoflow LC-ESI-MS/MS, 52 PL species were selected for quantitative analysis in urine samples between 22 cancer-free urologic patients as controls and 45 prostate cancer patients. Statistical treatment of data by receiver operating characteristic (ROC) analysis yielded 14 PL species that differed significantly in relative concentrations (area under curve (AUC) > 0.8) between the two groups. Among PLs present at higher levels in prostate cancer urine, phosphatidylcholines (PCs) and phosphatidylinositols (PIs) constituted the major head group PLs (3 PCs and 7 PIs). For technical reasons, PL species of low abundance may be underrepresented in data from UPLC-ESI-MS/MS performed in MRM mode. However, the proposed method enables the rapid screening of large numbers of plasma or urine samples in the search for biomarkers of human disease.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.9
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• pp.131-141
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• 2021

With the rapid development of the Internet, online shopping has grown so fast that almost any good or service can be sold online today. The popularity and rapid growth of e-commerce signal a huge market opportunity for e-retailers. From the organizational perspective, it is necessary to evaluate and explore what drives customers to buy their products or to use their services. This study, therefore, aims to explain the online purchase intention and its determinants of Vietnamese customers for cosmetics and personal care products. Quantitative data was collected from an online survey conducted among university students, then was put into SPSS and AMOS for further analysis. Descriptive statistics, Cronbach's alpha test, exploratory factor analysis (EFA), regression analysis, and SEM were used to examine data from 434 valid answers. The research findings reveal that four factors positively affect purchase intention: Shopping enjoyment has the most significant impact, followed by trust, benefit, and website quality. On the other hand, perceived risk negatively influences purchase intention. While the cosmetics and personal care industry is thriving with a huge number of producers and consumers throughout the world, this study contributes to the existing literature in terms of capturing customers' needs and developing effective strategies to attract more online users.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.151-162
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• 2022

This study was conducted to develop a rail-type boom sprayer, performing safe spraying with improved ergonomic postures during pesticide spraying of agro-photovoltaic power system. The sprayer was designed to reduce labor cost and to be safe from pesticide exposure, and was analyzed through a comparison with a conventional spray method. The rail-type boom sprayer, consisted of a self-propelled spray and hose winder, hose, and boom sprayer parts, was designed to automatically pull and spray in the vertical and horizontal directions. The performance of the sprayer for an agro-photovoltaic power system was appropriate. From the analysis of postures with the Ovako Working posture Analysis System (OWAS), Rapid Entire Body Assessment (REBA), and Rapid Upper Limb Assessment (RULA) methods, the musculoskeletal risk factors to the body using the rail-type boom sprayer were less than those with the conventional power sprayer. In addition, the possibility of pesticide poisoning was reduced compared to the conventional power sprayer. The working capacity with the rail-type boom sprayer was more than five times greater, compared with the conventional power sprayer. After performing pesticide spraying with the rail-type boom sprayer, the labor cost was reduced to 42,750 won·yr^-1, which was 90% (402,750 won·yr^-1) less than the cost with the use of a conventional power sprayer (445,500 won·yr^-1).

• Current Optics and Photonics
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• v.7 no.4
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• pp.435-442
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• 2023

These days, the size of a reflective telescope has been increasing for astronomical observation. An additional optical system usually assists a large ground telescope for image analysis or the compensation of air turbulence. To guide collimated light to the external optical system through a designated path, a coudé mirror is usually adopted. Including a collimator, a coudé mirror of a ground telescope is affected by gravity, depending on the telescope's pointing direction. The mirror surface is deformed by the weight of the mirror itself and its mount, which deteriorates the optical performance. In this research, we propose an optimization method for the coudé mirror assembly for a 1-m class ground telescope that minimizes the gravitational surface error (SFE). Here the mirror support positions and the sizes of the mount structure are optimized using finite element analysis and the response surface optimization method in both the horizontal and vertical directions, considering the telescope's altitude angle. Throughout the whole design process, the coefficients of the Zernike polynomials are calculated and their amplitude changes are monitored to determine the optimal design parameters. At the same time, the design budgets for the thermal SFE and the mass and size of the mount are reflected in the study.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.209-214
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• 2023

Background: Single nucleotide polymorphisms (SNPs) are widely used genetic markers with applications in human disease diagnostics, animal breeding, and evolutionary studies, but existing genotyping methods can be labor-intensive and costly. The aim of this study is to develop a simple and rapid method for identification of a single nucleotide change. Methods: A modified Polymerase Chain Reaction Amplification of Multiple Specific Alleles (PAMSA) and high resolution melt (HRM) analysis was performed to discriminate a bovine polymorphism in the NCAPG gene (rs109570900, 1326T > G). Results: The inclusion of tails in the primers enabled allele discrimination based on PCR product lengths, detected through agarose gel electrophoresis, successfully determining various genotypes, albeit with some time and labor intensity due to the use of relatively costly high-resolution agarose gels. Additionally, high-resolution melt (HRM) analysis with tailed primers effectively distinguished the GG genotype from the TT genotype in bovine muscle cell lines, offering a reliable way to distinguish SNP polymorphisms without the need for time-consuming AS-PCR. Conclusions: Our experiments demonstrated the importance of incorporating unique mismatched bases in the allele-specific primers to prevent cross-amplification by fragmented primers. This efficient and cost-effective method, as presented here, enables genotyping laboratories to analyze SNPs using standard real-time PCR.

• Radiation Oncology Journal
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• v.30 no.2
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• pp.53-61
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• 2012

Purpose: To determine feasibility of RapidArc in sequential or simultaneous integrated tumor boost in whole brain radiation therapy (WBRT) for poor prognostic patients with four or more brain metastases. Materials and Methods: Nine patients with multiple (${\geq}4$) brain metastases were analyzed. Three patients were classified as class II in recursive partitioning analysis and 6 were class III. The class III patients presented with hemiparesis, cognitive deficit, or apraxia. The ratio of tumor to whole brain volume was 0.8-7.9%. Six patients received 2-dimensional bilateral WBRT, (30 Gy/10-12 fractions), followed by sequential RapidArc tumor boost (15-30 Gy/4-10 fractions). Three patients received RapidArc WBRT with simultaneous integrated boost to tumors (48-50 Gy) in 10-20 fractions. Results: The median biologically effective dose to metastatic tumors was 68.1 $Gy_{10}$ and 67.2 $Gy_{10}$ and the median brain volume irradiated more than 100 $Gy_3$ were 1.9% (24 $cm^3$) and 0.8% (13 $cm^3$) for each group. With less than 3 minutes of treatment time, RapidArc was easily applied to the patients with poor performance status. The follow-up period was 0.3-16.5 months. Tumor responses among the 6 patients who underwent follow-up magnetic resonance imaging were partial and stable in 3 and 3, respectively. Overall survival at 6 and 12 months were 66.7% and 41.7%, respectively. The local progression-free survival at 6 and 12 months were 100% and 62.5%, respectively. Conclusion: RapidArc as a component in whole brain radiation therapy for poor prognostic, multiple brain metastases is an effective and safe modality with easy application.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.823-833
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• 2020

In order to stably produce crops, there is an increasing demand for effective crop monitoring techniques in domestic agricultural areas. In this manuscript, a cultivation area extraction method by using deep learning model is developed, and then, applied to satellite imagery. Training dataset for crop cultivation areas were generated using RapidEye satellite images that include blue, green, red, red-edge, and NIR bands useful for vegetation and environmental analysis, and using this, we tried to estimate the crop cultivation area of onion and garlic by deep learning model. In order to training the model, atmospheric-corrected RapidEye satellite images were used, and then, a deep learning model using FC-DenseNet, which is one of the representative deep learning models for semantic segmentation, was created. The final crop cultivation area was determined as object-based data through combination with cadastral maps. As a result of the experiment, it was confirmed that the FC-DenseNet model learned using atmospheric-corrected training data can effectively detect crop cultivation areas.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.547-554
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• 2006

The overall objective of this research was to find out the role of rapid mixing conditions in the species of hydrolyzed Al(III) formed by Al(III) coagulants and to evaluate the distribution of hydrolyzed Al(III) species by coagulant dose and coagulation pH. When an Al(III) salt was added to water, monomeric Al(III), polymeric Al(III), precipitate Al(III) was formed by Al(III) hydrolysis. The method of hydrolyzed Al(III) species characterization analysis was based on timed spectrophotometer with ferron as a color developing reagent. The hydrolytic species were divided into monomer, polymer, precipitate from the reaction kinetics. And then, the color intensity for monomeric Al(III) was read 3 min after mixing. With standard Al solution containing monomeric Al(III) only, the Al-ferron color intensity slightly increased with until about 3 min. During the rapid mixing period, for purewater, formation of dissolved Al(III) (monomer and polymer) was similar to rapid mixing condition, but for raw water, the species of Al(III) hydrolysis showed different result. During the rapid mixing period, for high coagulant dose, Al-ferron reaction increases rapidly. The kinetic constants, Ka and Kb, derived from Al-ferron reaction. The kinetic constants followed very well the defined tendencies for coagulation condition. For pure water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values. Also, for raw water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values.