• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.4
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• pp.41-50
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• 2024

Precipitation is an important component of the hydrological cycle and a key input parameter for many applications in hydrology, climatology, meteorology, and weather forecasting research. Grid-based satellite rainfall products with wide spatial coverage and easy accessibility are well recognized as a supplement to ground-based observations for various hydrological applications. The error properties of satellite rainfall products vary as a function of rainfall intensity, climate region, altitude, and land surface conditions. Therefore, this study aims to evaluate the commonly used new global grid-based satellite rainfall product, Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), using data collected at different spatial and temporal scales. Additionally, in this study, grid-based CHIRPS satellite precipitation data were used to evaluate the 2022 extreme drought. CHIRPS provides high-resolution precipitation data at 5 km and offers reliable global data through the correction of ground-based observations. A frequency analysis was performed to determine the precipitation deficit in 2022. As a result of comparing droughts in 2015, 2017, and 2022, it was found that May 2022 had a drought frequency of more than 500 years. The 1-month SPI in May 2022 indicated a severe drought with an average value of -1.8, while the 3-month SPI showed a moderate drought with an average value of 0.6. The extreme drought experienced in South Korea in 2022 was evident in the 1-month SPI. Both CHIRPS precipitation data and observations from weather stations depicted similar trends. Based on these results, it is concluded that CHIRPS can be used as fundamental data for drought evaluation and monitoring in unmeasured areas of precipitation.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1506-1512
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• 2023

Quantitative analysis of adenosine triphosphate (ATP) has been widely used as a diagnostic tool in the food and medical industries. Particularly, the pathogenesis of a few diseases including inflammatory bowel disease (IBD) is closely related to high ATP concentrations. A bioluminescent D-luciferin/luciferase system, which includes a luciferase (FLuc) from the firefly Photinus pyralis as a key component, is the most commonly used method for the detection and quantification of ATP. Here, instead of isolating FLuc produced in recombinant Escherichia coli, we aimed to develop a whole-cell biocatalyst system that does not require extraction and purification of FLuc. To this end, the gene coding for FLuc was introduced into the genome of probiotic Saccharomyces boulardii using the CRISPR/Cas9-based genome editing system. The linear relationship (r² = 0.9561) between ATP levels and bioluminescence generated from the engineered S. boulardii expressing FLuc was observed in vitro. To explore the feasibility of using the engineered S. boulardii expressing FLuc as a whole-cell biosensor to detect inflammation biomarker (i.e., ATP) in the gut, a colitis mouse model was established using dextran sodium sulfate as a colitogenic compound. Our findings demonstrated that the whole-cell biosensor can detect elevated ATP levels during gut inflammation in mice. Therefore, the simple and powerful method developed herein could be applied for non-invasive IBD diagnosis.

• Journal of Microbiology and Biotechnology
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• v.33 no.11
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• pp.1403-1411
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• 2023

Carbon dioxide (CO₂) is the most abundant component of greenhouse gases (GHGs) and directly creates environmental issues such as global warming and climate change. Carbon capture and storage have been proposed mainly to solve the problem of increasing CO₂ concentration in the atmosphere; however, more emphasis has recently been placed on its use. Among the many methods of using CO₂, one of the key environmentally friendly technologies involves biologically converting CO₂ into other organic substances such as biofuels, chemicals, and biomass via various metabolic pathways. Although an efficient biocatalyst for industrial applications has not yet been developed, biological CO₂ conversion is the needed direction. To this end, this review briefly summarizes seven known natural CO₂ fixation pathways according to carbon number and describes recent studies in which natural CO₂ assimilation systems have been applied to heterogeneous in vivo and in vitro systems. In addition, studies on the production of methanol through the reduction of CO₂ are introduced. The importance of redox cofactors, which are often overlooked in the CO₂ assimilation reaction by enzymes, is presented; methods for their recycling are proposed. Although more research is needed, biological CO₂ conversion will play an important role in reducing GHG emissions and producing useful substances in terms of resource cycling.

• Korean Medical Education Review
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• v.26 no.2
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• pp.93-107
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• 2024

Interprofessional education (IPE) is relatively new in medical schools in South Korea. Since the introduction of IPE in 2022, its effective and sustainable implementation has been of great interest in medical schools. This study analyzed literature on the development of IPE in the United States, Canada, the United Kingdom, Australia, and Japan to explore strategies for successful IPE in Korean medical schools. A systematic literature search focused on institutionalizing IPE yielded 30 papers for review. The findings included the following crucial elements for effective IPE: (1) government or institutional-led support; (2) establishment of networks and partnerships; (3) development of standardized core competency frameworks for IPE; and (4) inclusion of IPE in accreditation standards. These aspects underscore the importance of IPE as an essential component of health professional education that should be effectively and sustainably implemented in academic settings. The study concludes that the successful integration and sustainable development of IPE in Korean health education will necessitate expanded and proactive governmental support. Moreover, promoting collaborations among universities, hospitals, and local healthcare institutions will be vital for creating synergies in implementing IPE programs. Establishing networks to develop and execute joint IPE initiatives and securing initial support for conceptualizing and developing competency frameworks will be critical. Additionally, forming consortia of healthcare accreditation bodies to collaboratively develop and incorporate IPE standards into evaluation criteria will be essential. Efforts to surmount these challenges will contribute to building a structural and institutional support system for the successful introduction and sustainability of IPE in Korea.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.363-373
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• 2023

Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea's SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4367-4381
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• 2023

Nuclear power plants are increasingly being equipped with digital I&C systems. Although some probabilistic safety assessment (PSA) models for the digital I&C of nuclear power plants have been constructed, there is currently no specific internationally agreed guidance for their modeling. This paper presents an initiative by the OECD Nuclear Energy Agency called "Digital I&C PSA - Comparative application of DIGital I&C Modelling Approaches for PSA (DIGMAP)", which aimed to advance the field towards practical and defendable modeling principles. The task, carried out in 2017-2021, used a simplified description of a plant focusing on the digital I&C systems important to safety, for which the participating organizations independently developed their own PSA models. Through comparison of the PSA models, sensitivity analyses as well as observations throughout the whole activity, both qualitative and quantitative lessons were learned. These include insights on failure behavior of digital I&C systems, experience from models with different levels of abstraction, benefits from benchmarking as well as major contributors to the core damage frequency and those with minor effect. The study also highlighted the challenges with modeling of large common cause component groups and the difficulties associated with estimation of key software and common cause failure parameters.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.863-870
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• 2024

Meju, a fermented soybean brick, is a key component in soybean foods like doenjang and ganjang, harboring a variety of microorganisms, including bacteria and fungi. These microorganisms significantly contribute to the nutritional and sensory characteristics of doenjang and ganjang. Amplicon-based next-generation sequencing was applied to investigate how the microbial communities of meju fermented at low and high temperatures differ and how this variation affects the microbial communities of doenjang, a subsequently fermented soybean food. Our metagenomic data showed distinct patterns depending on the fermentation temperature. The microbial abundance in the bacterial community was increased under both temperatures during the fermentation of meju and doenjang. Weissella was the most abundant genus before the fermentation of meju, however, it was replaced by Bacillus at high temperature-fermented meju and lactic acid bacteria such as Weissella and Latilactobacillus at low temperature-fermented meju. Leuconostoc, Logiolactobacillus, and Tetragenococcus gradually took over the dominant role during the fermentation process of doenjang, replacing the previous dominant microorganisms. Mucor was dominant in the fungal community before and after meju fermentation, whereas Debaryomyces was dominant under both temperatures during doenjang fermentation. The dominant fungal genus of doenjang was not affected regardless of the fermentation temperature of meju. Strong correlations were shown for specific bacteria and fungi linked to specific fermentation temperatures. This study helps our understanding of meju fermentation process at different fermentation temperatures and highlights different bacteria and fungi associated with specific fermentation periods which may influence the nutritional and organoleptic properties of the final fermented soybean foods doenjang.

• Korean Journal of Optics and Photonics
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• v.35 no.4
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• pp.170-174
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• 2024

A laser beam propagating in free space can be negatively affected by atmospheric turbulence. To overcome this and correct the wavefront error of the laser beam itself, a deformable mirror (DM), which is a key component of adaptive optics, is widely used. In this paper, a novel precision assembling method is suggested for a multi-channel high-density DM. The material of the mirror sheet of the DM is silicon carbide (SiC), and the actuator is a stacked-type lead-magnesium-niobate (Pb(Mg_1/3Nb_2/3)O₃; PMN). To connect the mirror sheet and each actuator, a flexure is inserted. The flexure can make the DM operate with full strokes without the failure of adhesive. A series of jigs were designed and applied in order to assemble these three parts (the mirror sheet, actuators, and flexures) precisely. After assembly, the performance of the DM was also checked.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.4
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• pp.121-127
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• 2024

In this paper, FEM (Front-End Module) MMIC, a key component for the application of the satellite communication terminal transmission and reception module of the multi-phase array structure, was designed and verified as a single chip by designing the Power Amplifier (PA) and the Low Noise Amplifier (LNA). It was manufactured using the GaAs PP10 (100nm) process, a compound semiconductor process from Win-semiconductors, and the operating frequency band of 7.2-10.5GHz operation, output 1W, and noise index of 1.5dB or less were secured using a dedicated test board. The developed FEM MMIC can be used as a single chip, and the components PA and LNA can also be used as each device. The developed device will be used in various applications of Minsu/Gunsu using the X band and the localization of overseas parts.

• Oncology Reports
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• v.43 no.2
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• pp.655-661
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• 2020

Alterations in DNA methylation have a central role in the development and outcome of most human malignancies. Non-small cell lung cancer (NSCLC), the most common lung cancer, leads to the largest number of cancer-related deaths worldwide. FBJ murine osteosarcoma viral oncogene homolog B (FOSB) is a key component of the activator protein-1 transcription factor and regulates gene networks associated within oncogenic transformation. The role of FOSB in the development of NSCLC is still elusive. Therefore, the methylation status of the FOSB gene was investigated in NSCLC and its clinical significance in NSCLC progression was evaluated. The methylation status of the promoter and exon 4 regions of the FOSB gene were analyzed in 176 NSCLC specimens by bisulfite pyrosequencing and the association between FOSB methylation status and patient survival was investigated. Compared to adjacent non-malignant tissues, FOSB promoter exhibited exclusive unmethylation in all malignant tissues and the exon 4 region was found unmethylated in 18 (10.2% of the total) tumor samples. Exon 4 unmethylation was associated with downregulation of its mRNA and tended to occur in patients with lymph node metastasis. Univariate and multivariate analyses revealed that exon 4 unmethylation was significantly associated with unfavorable overall survival in patients with stage II-IIIA NSCLC (log-rank P=0.05, adjusted hazard ratio=2.43, 95% confidence interval=1.04-5.68, P=0.04). FOSB was identified as a novel gene with tumor-specific gene body unmethylation in NSCLC and a novel predictive biomarker for NSCLC prognosis. Moreover, the present results indicated that FOSB may have a tumor suppressor function in the progression of NSCLC.