• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.70-79
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• 2024

Raman analyzer is an analytical technique that utilizes the "Raman effect", which occurs when light is scattered by the inherent vibrations of molecules. It is used for molecular identification and composition analysis. In the natural gas industry, it is widely used in bunkering and tank lorry fields in addition to LNG export and import terminals. In this study, a LNG-specific Raman analyzer was installed and operated under actual field conditions to analyze the composition and principal properties (calorific value, reference density, etc.) of LNG. The measured LNG composition and calorific value were compared with those obtained by conventional gas chromatograph that are currently in operation and validated. The test results showed that the Raman analyzer provided rapid and stable measurements of LNG composition and calorific value. When comparing the calorific value, which serves as the basis for LNG transactions, with the results from conventional gas chromatograph, the Raman analyzer met the acceptable error criteria. Furthermore, the measurement results obtained in this study satisfied the accuracy criteria of relevant international standards (ASTM D7940-14) and demonstrated similar outcomes compared to large-scale international demonstration cases.

• Information Systems Review
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• v.22 no.1
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• pp.147-165
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• 2020

The sharing economy service is now spreading in various fields such as accommodation, cars and bicycles. In particular, bicycle-sharing service have become very popular around the world, and since September 2015, Seoul has been providing a bicycle-sharing service called 'Ttareungi'. However, the number of bicycles is unbalanced among rental stations continuously according to the user's bicycle use. In order to solve these problems, we employed social network analysis using Ttareungi data in Seoul, Korea. We analyzed degree centrality, closeness centrality, betweenness centrality and k-core. As a result, the degree centrality was found to be closely linked with bus or subway transfer center. Closeness centrality was found to be in an unbalanced departure and arrival frequency or poor public transport proximity. Betweenness centrality means where the frequency of departure and arrival occurs frequently. Finally, the k-core analysis showed that Mapo-gu was the most important group by time zone. Therefore, the results of this study may contribute to the planning of relocation and additional installation of bike rental station in Seoul.

• Journal of The Korean Association For Science Education
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• v.44 no.1
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• pp.119-130
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• 2024

This study explores the possibility of using a generative artificial intelligence, ChatGPT, for student assessment in science subjects. In order to achieve our goal, we developed assessment items, collected students' responses, and input them into ChatGPT to implement the assessment procedures. Subsequently, we shared the assessment results from ChatGPT with science teachers and compared them to the teachers' assessment process to investigate the use of ChatGPT in student assessment. Regarding the results, in terms of setting the scoring rubric, we found the rubric generated by ChatGPT to be generally appropriate. However, the consistency between the scoring results obtained from ChatGPT and those determined by the teachers was relatively low. This inconsistency was more pronounced in items with additional assessment components and a more intricate rubric. In regard to feedback on student responses, there were some instances where the feedback generated was scientifically incorrect or beyond the scope of the curriculum, but there were also some positives, such as the provision of exemplary answers to questions and additional examples that helped students learn further. From these results, the teachers perceived limitations in using ChatGPT to conduct assessment in terms of reliability, which is considered crucial in student assessment, but suggested that it could be used to support assessment. Finally, synthesizing these findings, implications for utilizing ChatGPT in student assessment were suggested.

• Journal of Industrial Convergence
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• v.22 no.3
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• pp.39-49
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• 2024

The purpose of this study was to explore the meaning of the teaching experience of middle school physical education teachers, listening to in-depth statements related to teaching experience based on the physical education teacher's teaching identity, and analyzing the meaningful content and meaning structure found therein. The study participants were four current middle school physical education teachers. The research method used Colaizzi's phenomenological method to analyze the meaning structure through in-depth interviews with research participants, group interviews, additional interviews, and field records. In order to solve the research questions, the interviews were conducted as semi-structured interviews, and the individual interviews were terminated when there were no more duplicate cases or similar phenomena related to teaching experience. As a result of the study, the meaning of experience was constructed based on narrative statements through interviews with research participants, and a collection of 2 items, 6 categories, and 12 themes were extracted by exploring concepts from the constructed meaning. The reasons for going into the teaching profession were categorized into 'motivation' and 'beliefs', and the meaning of teaching experience was categorized into 'mission', 'relationships', 'exhaustion', and 'overcoming'. In conclusion, although the research participants faced numerous difficulties, they experienced challenges and recovery by pursuing the joy and value of sharing within the school community.

• Journal of Mushroom
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• v.22 no.1
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• pp.31-36
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• 2024

Plastics are widely used in industries in human society and because of their structural stability, degradation is a serious global issue. To estimate the degradation of plastic, 31 edible mushrooms were cultured with the selected plastic films (polyethylene [PE], polystyrene [PS], and poly(ethylene terephthalate) [PET]) for 3 months at 25 ℃. Measuring the weight of the films showed that four species of mushrooms, namely Porostereum spadiceum, Ganoderma lucidum, Coprinellus micaceus, and Pleurotus ostreatus, exhibited the highest degrees of plastic degradation. In addition, the mushrooms and fungi that exhibited the most significant plastic degradation were cross-cultured to promote this degradation. As a result, cross-cultivation of G. lucidum and Aspergillus niger showed a weight loss of 2.49% for the PET film. For the PS film, Aspergillus nidulans showed a weight loss of 4.06%. Cross-cultivation of A. nidulans and C. micaceus, which showed a weight loss of 2.95%, was noted as an alternative for PS biodegradation, but is harmful to humans. These bio-degradation effects of edible mushroom will contribute to the development of alternatives for eco-friendly plastic degradation.

• Journal of Mushroom
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• v.22 no.1
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• pp.22-26
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• 2024

Tricholoma matsutake is a traditional favorite food in East Asia, cultivated in fairy rings called "shiro," which are found near Pinus densiflora. For effective artificial cultivation of Tri. matsutake, microorganisms from symbiotic fairy rings are co-cultivated. In this study, one bacterial isolate (Y22_B35) and two fungal isolates (Y22_F64 and Y22_F68) displayed growth-promoting effects on Tri. matsutake mycelium (158.47, 125.00, and 122.26% enhanced growth, respectively). For identification, 16S rRNA or ITS regions from the microorganisms¡¯ genomes were sequenced. Other sequences, including BenA, CaM, and RPB2 were sequenced in the fungal isolates. The bacterial isolate Y22_B35 was identified as Bacillus cereus. Y22_F64 and Y22_F68 were identified as Umbelopsis nana and Aspergillus parvulus, respectively. To identify the effects of the dominant microorganisms on Tri. Matsutake cultivation, metagenomic analyses were performed. Discovery of these Tri. matsutake mycelium growth-promoting microorganisms and metagenomics analyses are expected to contribute to our understanding of Tri. matsutake fruiting body growth and construction of biomimicry.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.99-114
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• 2024

Domestic coastal debris monitoring encounters challenges due to labor-intensive methods and limited survey scope. Consequently, research is utilizing remote sensing techniques to enhance efficiency in data collection. However, standards for domestic remote sensing based monitoring methods remain insufficient. In this study, we conducted a meta-analysis of 19 coastal debris monitoring studies utilizing drones and other remote sensing devices. We analyzed data collection methods, collected data information, monitoring target details, monitoring status, detection targets, and utilization models. Based on our meta-analysis results, we proposed monitoring criteria, recommended items, and performance standards for monitoring coastal debris using drones. Our findings define necessary conditions and standards for establishing operational guidelines for coastal debris monitoring using drones. Furthermore, we anticipate that incorporating foreign case analyses and field application results will enable the development of national-level guidelines for coastal debris monitoring utilizing remote sensing devices.

• Korean Journal of Ecology and Environment
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• v.57 no.3
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• pp.162-168
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• 2024

The purpose of this study was to record for the first time in Korea the presence of Melanoides tuberculata (an invasive alien species), which was confirmed during the "National Survey on the Status of Alien Species" in Jukdang stream (also known as Guppy Stream, located in Icheon, Gyeonggi Province), which is affected by the year-round discharge of heated effluent from a large semiconductor factory and where various tropical organisms, including ornamental fish, appear due to artificial release. A Total of 52 specimens were collected, and they can be visually distinguished from native melanian snails by their reddish-brown flames and spots. Genetic analysis further confirmed the species as Melanoides tuberculate. Melanoides tuberculata typically inhabits tropical climates, but its presence has been confirmed in altered aquatic environments such as Jukdang stream, where the water temperature remains warm even in a temperate climate. This indicates the need for further monitoring of domestic streams with similar conditions, particularly those receiving heated effluent, like Jukdang stream. Additionally, due to its strong reproductive capacity, including parthenogenesis, and its adaptability to various environments, there have been cases where the populations of Pomacea lineata and Aylacostoma tenuilabris have declined. This suggests that Melanoides tuberculata may have a competitive advantage in interspecific competition, potentially suppressing native species populations if it spreads within the domestic ecosystem. Melanoides tuberculata serves as an intermediate host for parasites that can cause diseases in both humans and animals, raising public health concerns in many countries. There is also a significant risk that it could be mistaken for native melanian snail species and consumed, which necessitates a high level of caution.

• Journal of the Korean Society for information Management
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• v.41 no.3
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• pp.1-32
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• 2024

This study aims to explore the utilization of kiosks, a case of self-service technology in library services, by applying task-technology fit theory to reveal the factors that affect the satisfaction and continued use of library kiosk services and to conduct a review of library non-face-to-face services. We organized the kiosk characteristic factors through a literature review and established a research model mediated by related theories. We collected 229 valid questionnaire data from users with experience using library kiosks and analyzed them using SPSS 26.0 and SmartPLS 4.0 programs. The analysis results confirmed that the fit of library services and self-service technology was significantly influenced by the usefulness and enjoyment of kiosk technology characteristics and the kiosk-friendly environment of the usage environment attributes. In addition, we found the fit between library services and self-service technology to significantly affect library kiosk usage satisfaction and intention to continue using the kiosk, so this study proposed a plan for library kiosk services utilizing the significant factors. In addition, to effectively use the kiosks as a non-face-to-face library service, we suggest operating them in line to provide library information materials, install them in various locations within the library to increase accessibility, and provide education on how to use them for learning and to raise positive awareness of the kiosks for the digitally disadvantaged.

• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.422-435
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• 2024

This study intended to verify the effects of face masks on the Korean language in terms of acoustic, aerodynamic, and formant parameters. We chose all types of face masks available in Korea based on filter performance and folding type. Two professional voice actors (a male and a female) with more than 20 years of experience who are native Koreans and speak standard Korean participated in this study as speakers of voice data. Face masks attenuated the high-frequency range, resulting in decreased Vowel Space Area (VSA) and Vowel Articulation Index (VAI)scores and an increased Low-to-High spectral ratio (L/H ratio) in all voice samples. This can result in lower speech intelligibility. However, the degree of increment and decrement was based on the voice characteristics. For female speakers, the Speech Level (SL) and Cepstral Peak Prominence (CPP) increased with increasing face mask thickness. In this study, the presence or filter performance of a face mask was found to affect speech acoustic parameters according to the speech characteristics. Face masks provoked vocal effort when the vocal intensity was not sufficiently strong, or the environment had less reverberance. Further research needs to be conducted on the vocal efforts induced by face masks to overcome acoustic modifications when wearing masks.