• Journal of Platform Technology
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• v.11 no.6
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• pp.89-105
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• 2023

With the development of information technology, most of the information has been converted into digital information, leading to the Big Data era. The demand for search platform has increased to enhance accessibility and usability of information in the databases. Big data search software platforms consist of two main components: (1) an indexing component to generate and store data indices for a fast and efficient data search and (2) a searching component to look up the given data fast. As an amount of data has explosively increased, data indexing performance has become a key performance bottleneck of big data search platforms. Though many companies adopted big data search platforms, relatively little research has been made to improve indexing performance. This research study employs Elasticsearch platform, one of the most famous enterprise big data search platforms, and builds physical clusters of 3 nodes to investigate optimal indexing performance configurations. Our comprehensive experiments and studies demonstrate that the proposed optimal Elasticsearch configuration achieves high indexing performance by an average of 3.13 times.

• Journal of The Korea Institute of Healthcare Architecture
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• v.30 no.3
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• pp.67-74
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• 2024

Purpose: The identification and quantification of indoor airborne contaminants, including bio-aerosols, particulates, and gaseous contaminants, are crucial for maintaining acceptable indoor air quality for hospital operating rooms (ORs). Laparoscopic surgery has become widely accepted for various surgical procedures due to its rapid recovery rate and the low risk associated with small incisions compared to conventional open surgery. The objective of this study is to investigate the indoor air quality in hospital ORs and to identify indoor airborne contaminants generated during laparoscopic surgery. Methods: Measurements of an indoor environment, including temperature, humidity and air quality, were performed in an OR before and during a laparoscopic surgery. Indoor airborne contaminants, including volatile organic compounds (VOCs), formaldehyde, carbon monoxide (CO), carbon dioxide (CO₂), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), suspended indoor particles, and airborne bacteria, were measured simultaneously. Results: The study determined that the concentrations of indoor air particles and airborne bacteria increased during the surgery but were within acceptable levels. However, the concentration of CO₂, reached a high level of 1,791 ppm due to the CO₂ gas required for maintaining the pneumoperitoneum during the surgery. Implications: The results emphasized the use of ventilation and filtration in a laparoscopic surgery room to lower the concentration of filterable and non-filterable contaminants.

• Journal of Navigation and Port Research
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• v.48 no.4
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• pp.294-302
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• 2024

The risks in global grain markets have increased due to COVID-19, extreme weather, natural disasters, and the Russia-Ukraine conflict. Additionally, in Korea, the locations for grain manufacturing have shifted owing to various factors. Despite these environmental changes, grain handling ports in Korea are limited in their capacity to respond promptly, resulting in operational inefficiencies. This study clarified changes in grain throughput and analyzed the efficiency of grain handling ports using the Super-SBM model. It suggested that the ports in Pyeongtaek and Gunsan were the most efficient, based on CCR and BCC results in 2022. These findings could provide several insights related to port operating plans for port operators, managers, and developers.

• Journal of Korean Library and Information Science Society
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• v.55 no.3
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• pp.241-262
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• 2024

This study aims to develop and validate a diagnostic tool capable of objectively measuring the digital literacy competencies of college students and also to analyze how learners' personal characteristics and perceptions are related to these competencies. Through literature review and surveys, a diagnostic tool comprising 6 major factors and 38 items was developed. The findings of the relationships between digital literacy and learners' personal characteristics and perceptions revealed that personal characteristics such as gender, age, education level, and college affiliation as well as grades did not significantly affect on digital literacy competencies. However, learners' perceptions towards satisfaction with major, overall academic satisfaction, ability to utilize digital devices for learning, usefulness of digital devices for learning, and frequency of digital device use for learning positively impacted digital literacy competencies. Based on the results, implications are suggested to facilitate self-regulation, participation, utilization, and evaluation competencies in digital literacy.

• Journal of Life Science
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• v.29 no.6
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• pp.653-661
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• 2019

The first small interfering RNA (siRNA) therapeutics have recently been approved by the Food and Drug Administration in the U.S., and the demand for a new RNA therapeutics bioanalysis method-which is essential for pharmacokinetics, including the absorption, distribution, metabolism, and excretion of siRNA therapeutics-is rapidly increasing. The stem-loop real-time qPCR (RT-qPCR) assay is a useful molecular technique for the identification and quantification of small RNA (e.g., micro RNA and siRNA) and can be applied for the bioanalysis of siRNA therapeutics. When the anti-HPV E6/E7 siRNA therapeutic was used in preclinical trials, the established stem-loop RT-qPCR assay was validated. The limit of detection was sensitive up to 10 fM and the lower limit of quantification up to 100 fM. In fact, the reliability of the established test method was further validated in three intra assays. Here, the correlation coefficient of $R^2$>0.99, the slope of -3.10 ~ -3.40, and the recovery rate within ${\pm}20%$ of the siRNA standard curve confirm its excellent robustness. Finally, the circulation profiles of siRNAs were demonstrated in rat serum, and the pharmacokinetic properties of the anti-HPV E6/E7 siRNA therapeutic were characterized using a stem-loop RT-qPCR assay. Therefore, the stemloop RT-qPCR assay enables accurate, precise, and sensitive siRNA duplex quantification and is suitable for the quantification of small RNA therapeutics using small volumes of biological samples.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.2
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• pp.87-102
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• 2022

To clarify the spatial distribution pattern of macrozoobenthos in Korean coastal waters in the summer season and investigate the relationship between community structure and benthic environmental factors, field surveys on community structure and benthic environmental factors were conducted at 117 stations in August 2017. A total of 613 macrobenthic species were identified, with the mean density of 1,228 ind./m² and the mean biomass (wet weight) of 110.9 g WW/m². Rich biodiversity was found at stations near Wando and along the coast of the East Sea, and there is a trend that stations with greater biodiversity also showed higher mean density as well. The dominant species in all the coastal areas in Korea was Heteromastus filiformis, which were found at most of the stations during the survey. The relatively deep areas in the East Sea were dominated by Magelona johnsoni and Maldane cristata, which were the third and ninth dominant species in the study areas, respectively. Pseudopolydora kempi and Rhynchospio sp. were observed only at the station located in the Nakdong River estuary. From the cluster analysis the stations could be clustered into three station groups with more similar faunal composition. Group A was located in the eastern coast, characterized with deep water depth and low levels of sand contents, while Group B was located in the southern coast, characterized by shallow depth of water and high content of mud and organic matter. Lastly, Group C was in the western coast, demonstrating low levels of mud content and organic matters. The biodiversity of macrobenthic species in the study area showed high positive correlation coefficients with benthic environmental factors such as sorting, clay, silt, and contents of organic matter in sediments, but negatively correlated with the sand contents. Major dominant species, Theora lata and Eriopisella sechellensis, both showed negative correlation coefficients with the sand contents, but a relatively high positive correlation with the levels of organic contents.It can be concluded that the spatial distribution patterns of macrobenthic organisms in Korean coastal waters are affected by depth, sediment type, and contents of organic matters.

• Research in Plant Disease
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• v.28 no.4
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• pp.221-230
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• 2022

The fire blight caused by Erwinia amylovora (Ea) was first reported in 2015 in Korea, and the disease has rapidly spread to 22 regions until 2021. In Korea, all host plants in the apple and pear orchards where fire blight occurred should be eliminated and buried by the Plant Protection Act. To prevent the spread of the disease, all burial sites were prohibited from planting the new host plants for the next three years. To confirm the eradication efficiency of Ea and the reoccurrence of fire blight, the surveillance facilities were established on three burial sites from 2019 to 2020 in Anseong-si, Gyeonggi-do, and Chungju-si, Chungcheongbuk-do. As host plants, five apple trees of fire blight-susceptible cultivar 'Fuji', were planted in each facility. All facilities were enclosed with fences and nets and equipped with two CCTVs, motion sensors, and several other sensors for recording weather conditions to monitor the environment of the sentinel plants in real-time. The sentinel plants were checked for the reoccurrence of fire blight routinely. Suspicious plant parts were collected and analyzed for Ea detection by loop-mediated isothermal amplification polymerase chain reaction and conventional polymerase chain reaction. Until November 2022, Ea has not been detected in all sentinel plants. These results might support that the burial control of infected plants in soil works efficiently to remove Ea and support the possibility to shorten the prohibition period of host plant establishment in the burial sites.

• Resources Recycling
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• v.31 no.6
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• pp.44-51
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• 2022

In the steelmaking process using an electric arc furnace (EAF), light-burnt dolomite, which is a flux containing MgO, is used to protect refractory materials and improve desulfurization ability. Furthermore, a recarburizing agent is added to reduce energy consumption via slag foaming and to induce the deoxidation effect. Herein, a waste MgO-C based refractory material was used to achieve the aforementioned effects economically. The waste MgO-C refractory materials contain a significant amount of MgO and graphite components; however, most of these materials are currently discarded instead of being recycled. The mass recycling of waste MgO-C refractory materials would be achievable if their applicability as a flux for steelmaking is proven. Therefore, experiments were performed using a target composition range similar to the commercial EAF slag composition. A pre-melted base slag was prepared by mixing SiO₂, Al₂O₃, and FeO in an alumina crucible and heating at 1450℃ for 1 h or more. Subsequently, a mixed flux #2 (a mixture of light-burnt dolomite, waste MgO-C based refractory material, and limestone) was added to the prepared pre-melted base slag and a melting reaction test was performed. Injecting the pre-melted base slag with the flux facilitates the formation of the target EAF slag. These results were compared with that of mixed flux #1 (a mixture of light-burnt dolomite and limestone), which is a conventional steelmaking flux, and the possibility of replacement was evaluated. To obtain a reliable evaluation, characterization techniques like X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) spectrometry were used, and slag foam height, slag basicity, and Fe recovery were calculated.

• Journal of Practical Engineering Education
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• v.11 no.2
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• pp.195-206
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• 2019

Accelerated technological advances and the convergence of information and communication technologies have led to changes of career concepts from one of lifetime employment to that of lifetime career. Given the importance of continuous career development for workers these days, systematic supports for workers' career development at the national level is necessary. Accordingly, a conceptual model of career competency mobility map (CCMM) has been proposed to support the development of workers' career competencies. The purpose of this study is to identify key issues that we should consider for real implementation by applying to each stage of the CCMM conceptual model as a case study. Based on the procedure presented in the conceptual model, the research process which includes collecting user information, conducting self-diagnosis of NCS-based job competencies, deriving necessary training competency, offering the guidance of training programs and job information were conducted. The results of the case study showed our participants' scores of competencies required further development and ranged from 1.83 to 4.52. Sequentially, a personalized information profile was offered for competency development, including training, certificates, and job information. Participants stated that the diagnosis results and profiles were meaningful and helped to explore further career development. Based on the results, implications are suggested.

• Journal of Engineering Education Research
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• v.10 no.4
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• pp.58-77
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• 2007

An evaluation system of teaching is one of authentic assessment tools for improving the quality of higher education. The purpose of this study is to cultivate the class evaluation system in the college of engineering based on the empirical analysis of the results of the class evaluation. Especially, this study investigates the validity evidence using the confirmatory factor analysis of the class evaluation. The data used in this study were acquired from 49,127 student's evaluation responses of 471 courses offered in colleges of natural science and engineering at a university in Korea. The reliabilities are quite good for every construct by producing an index value from 0.92 to 0.98. The results provides a guideline for an appropriate measurement model to report the information, to clarify quality and appropriateness of instrument items, to make recommendations for which items should be left or merged in the revised instrument. A special suggestion for improving student's evaluation of each course is to prepare a well-designed instruction for students explaining why and how to evaluate the course in order to produce reliable and valid results.