• Journal of Service Research and Studies
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• v.13 no.4
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• pp.160-172
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• 2023

The metaverse, derived from the fusion of "meta" and "universe," encompasses a three-dimensional virtual realm where avatars actively participate in a range of political, economic, social, and cultural activities. With the recent development of the metaverse, the traditional way of experiencing services is changing. While existing studies have mainly focused on the technological advancements of metaverse services (e.g., scope of technological enablers, application areas of technologies), recent studies are focusing on evaluating the quality of experience (QoE) of metaverse services from a customer perspective. This is because understanding and analyzing service characteristics that determine QoE from a customer perspective is essential for designing successful metaverse services. However, relatively few studies have explored the customer-oriented approach for QoE evaluation thus far. This study conducted an online review analysis using text mining to overcome this limitation. In particular, this study analyzed 227,332 online reviews of the Roblox service, known as a representative metaverse service, and identified points for improving the Roblox service based on the analysis results. As a result of the study, nine service features that can be used for QoE evaluation of metaverse services were derived, and the importance of each feature was estimated through relationship analysis with service satisfaction. The importance estimation results identified the "co-experience" feature as the most important. These findings provide valuable insights and implications for service companies to identify their strengths and weaknesses, and provide useful insights to gain an advantage in the changing metaverse service environment.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.755-770
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• 2023

Due to recent severe climate change, abnormal weather phenomena, and other factors, the frequency and magnitude of natural disasters are increasing. The need for disaster management using artificial satellites is growing, especially during large-scale disasters due to time and economic constraints. In this study, we have summarized the current status of next-generation medium-sized satellites and microsatellites in operation and under development, as well as trends in satellite imagery analysis techniques using a large volume of satellite imagery driven by the advancement of the space industry. Furthermore, by utilizing satellite imagery, particularly focusing on recent major disasters such as floods, landslides, droughts, and wildfires, we have confirmed how satellite imagery can be employed for damage analysis, thereby establishing its potential for disaster management. Through this study, we have presented satellite development and operational statuses, recent trends in satellite imagery analysis technology, and proposed disaster response strategies that utilize various types of satellite imagery. It was observed that during the stages of disaster progression, the utilization of satellite imagery is more prominent in the response and recovery stages than in the prevention and preparedness stages. In the future, with the availability of diverse imagery, we plan to research the fusion of cutting-edge technologies like artificial intelligence and deep learning, and their applicability for effective disaster management.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.743-754
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• 2023

The global occurrence of myriad natural disasters and incidents, catalyzed by climate change and extreme meteorological conditions, has engendered substantial human and material losses. International organizations such as the International Charter have established an enduring collaborative framework for real-time coordination to provide high-resolution satellite imagery and geospatial information. These resources are instrumental in the management of large-scale disaster scenarios and the expeditious execution of recovery operations. At the national level, the operational deployment of advanced National Earth Observation Satellites, controlled by National Geographic Information Institute, has not only catalyzed the advancement of geospatial data but has also contributed to the provisioning of damage analysis data for significant domestic and international disaster events. This special edition of the National Disaster Management Research Institute delineates the contemporary landscape of major disaster incidents in the year 2023 and elucidates the strategic blueprint of the government's national disaster safety system reform. Additionally, it encapsulates the most recent research accomplishments in the domains of artificial satellite systems, information and communication technology, and spatial information utilization, which are paramount in the institution's disaster situation management and analysis efforts. Furthermore, the publication encompasses the most recent research findings relevant to data collection, processing, and analysis pertaining to disaster cause and damage extent. These findings are especially pertinent to the institute's on-site investigation initiatives and are informed by cutting-edge technologies, including drone-based mapping and LiDAR observation, as evidenced by a case study involving the 2023 landslide damage resulting from concentrated heavy rainfall.

• Journal of Industrial Convergence
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• v.21 no.9
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• pp.33-39
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• 2023

Nano-sized materials can be coated on various substrates, and since this material is transparent and conductive, it can be used as a transparent electrode for electronic devices or an electrode for power supply. In this study, CNT and Ag nanowires were repeatedly coated using the silk screen technique, and samples formed up to 5 times were fabricated, and their optical and electrical properties were measured and analyzed. It was confirmed that marks were formed on the surface of the silkscreen-coated sample according to the coating direction, and the trend of transmittance and surface resistance according to the number of times of coating was investigated. As the number of coatings increased, transmittance and surface resistance tended to decrease. In particular, in the case of transmittance, the range of change was large in the samples coated 2 and 5 times. These changes were confirmed by the Ag nanowire coating. In addition, starting from 700 nm, the previous wavelength region increased according to the wavelength, while the above showed a tendency to decrease. The surface resistance was lowered from 9Ω/cm² when coating once to 0.856Ω/cm² when coating five times. It was found that the resistance value was affected by Ag similarly to the permeability. In the future, it is necessary to realize a desired transparent electrode through Ag concentration and coating of Ag nanowires with other methods and fusion with highly transparent CNT to apply to electronic devices.

• Journal of the Korean Society of Radiology
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• v.18 no.1
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• pp.37-44
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• 2024

Even though MR can reveal excellent soft-tissue contrast and functional information, CT is also required for electron density information for accurate dose calculation in Radiotherapy. For the fusion of MRI and CT images in RT treatment planning workflow, patients are normally scanned on both MRI and CT imaging modalities. Recently deep-learning-based generations of CT images from MR images became possible owing to machine learning technology. This eliminated CT scanning work. This study implemented a CycleGan deep-learning-based CT image generation from MR images. Three CT generators whose learning is based on T1- , T2- , or T1-&T2-weighted MR images were created, respectively. We found that the T1-weighted MR image-based generator can generate better than other CT generators when T1-weighted MR images are input. In contrast, a T2-weighted MR image-based generator can generate better than other CT generators do when T2-weighted MR images are input. The results say that the CT generator from MR images is just outside the practical clinics and the specific weight MR image-based machine-learning generator can generate better CT images than other sequence MR image-based generators do.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.196-205
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• 2024

In this study, sample collection and quantification analysis of Tire and Road Wear Particles (TRWP) from the road surface were conducted to predict the amount of TRWP generated on the road surface moving by environmental compartment depending on rainfall intensity. Samples were collected from TRWP remaining on the road surface two days after the 3 days average rainfall (0-60 mm/day) occurred and the road surface was completely dry. Only TRWP were separated from the collected samples through size and density separation, and the difference in the content of TRWP remaining on the road surface after rainfall was based on the value of 60.2 g o f TRWP o n a day witho ut rain (0 mm/day). By calculating, it was co nfirmed that 0-49.4 g o f TRWP can mo ve to the environmental compartment depending on the intensity of rainfall. In addition, it was confirmed that when the rainfall intensity was 60 mm/day, the amount of TRWP moving to each environmental section was 3.75 times higher compared to 5 mm/day, and using the results of previous research, the total amount of TRWP that can be transported to the environmental compartment by rainfall from the domestic road environment annually is 9,592 tons, and 288 tons of this can be affected by marine microplastics. However, this study has limitations in terms of limited space and predicted results, but it would like to mention the need to improve the domestic road environment and sewage treatment system to reduce TRWP. In the future, we plan to conduct sample collection and concentration analysis studies of TRWP in real environmental compartments to verify the results of this study.

• Journal of Plant Biotechnology
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• v.50
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• pp.34-44
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• 2023

The tetraploid Solanum hjertingii, a wild tuber-bearing species from Mexico is a relative of potato, S. tuberosum. The species has been identified as a potential source of resistance to blackening for potato breeding. It does not exhibit enzymatic browning nor blackspot which are physiological disorders. However, due to their sexual incompatibility, somatic hybridization between S. hjertingii and S. tuberosum must be used to introduce various traits from this wild species into potato. After somatic hybridization, molecular markers are essential for selecting fusion products. In this study, the chloroplast genome of S. hjertingii was sequenced by next-generation sequencing technology and compared with those of other Solanum species to develop specific markers for S. hjertingii. The chloroplast genome has a total sequence length of 155,545 bp, and its size, gene content, order and orientation are similar to those of the other Solanum species. Phylogenic analysis including 15 other Solanaceae species grouped S. hjertingii with S. demissum, S. hougasii, and S. stoloniferum. After detailed comparisons of the chloroplast genome sequence with eight other Solanum species, we identified one InDel and seven SNPs specific to S. hjertingii. Based on these, five PCR-based markers were developed for discriminating S. hjertingii from other Solanum species. The results obtained in this study will aid in exploring the evolutionary aspects of Solanum species and accelerating breeding using S. hjertingii.

• Journal of Plant Biotechnology
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• v.50
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• pp.45-55
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• 2023

The diploid Solanum cardiophyllum, a wild tuberbearing species from Mexico is one of the relatives to potato, S. tuberosum. It has been identified as a source of resistance to crucial pathogens and insects such as Phytophthora infestans, Potato virus Y, Colorado potato beetle, etc. and is widely used for potato breeding. However, the sexual hybridization between S. cardiophyllum and S. tuberosum is limited due to their incompatibility. Therefore, somatic hybridization can introduce beneficial traits from this wild species into the potato. After somatic hybridization, selecting fusion products using molecular markers is essential. In the current study, the chloroplast genome of S. cardiophyllum was sequenced by next-generation sequencing technology and compared with those of other Solanum species to develop S. cardiophyllum-specific markers. The total length of the S. cardiophyllum chloroplast genome was 155,570 bp and its size, gene content, order and orientation were similar to those of the other Solanum species. Phylogenic analysis with 32 other Solanaceae species revealed that S. cardiophyllum was expectedly grouped with other Solanum species and most closely located with S. bulbocastanum. Through detailed comparisons of the chloroplast genome sequences of eight Solanum species, we identified 13 SNPs specific to S. cardiophyllum. Further, four SNP-specific PCR markers were developed for discriminating S. cardiophyllum from other Solanum species. The results obtained in this study would help to explore the evolutionary aspects of Solanum species and accelerate breeding using S. cardiophyllum.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.133-141
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• 2007

There are produced more than 600,000 tons of seaweeds every year along the coast of the Korea. Jeonnam province, south-west coast area, of Korea is producing 93% of total amounts of seaweeds. The laver, sea mustard, and tangleweed maintain stability in the output and has been exported as a simple product processing through drying or salting. It was evaluated the low value-added products and limited the expansion for the consumption of seaweeds. The seaweeds contains 40-60% carbohydrate and structurally different compared with land plant. The dietary fiber from seaweeds has been known the function of facilitating the bowl movement, excretion the heavy metal in the body, lowering the blood cholesterol level, anti-coagulant of blood, and anticancer. Especially, brown algae including sea mustard, seaweed fusiforme, and tangleweed contains alginic acid, laminarin, mannitol, fucoidan which are lowering the blood cholesterol level, lowering blood pressure, and fusion of blood clot. Agar-agar, carrageenan, and porphyran compound in red algae are known to antimutagenicity and anticoagulant function. In spite of potential of seaweed as a main bio-resource, there are lack of research to facilitate the consumption with its functional properties and consumers are unsatisfied with simple processing products. Also, the seaweed by-product dump into the sea and cause pollution of the seawater. Therefore, there are needed the scheme to promote the consumption of seaweeds. The development of value-added products, finding functional properties from seaweeds, development the functional feed for animal using seaweed by-products, and utilization of unused algae for food or other industrial uses will increase fisherman's income as well as serve as an aid for the people health due to its functional properties. Using by-product of seaweed and unexploited seaweed are needed to development of bio-degradable food packaging material and functional feed for animal.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.1-10
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• 2018

Recently, there has been rapid development in the field of flexible electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells and flexible sensors. Encapsulation process is added to protect the flexible electronic devices from exposure to oxygen and moisture in the air. Using numerical simulation, we investigated the effects of the encapsulation layer on mechanical stability of the silicon chip, especially the fracture performance of center crack in multi-layer package for various loading condition. The multi-layer package is categorized in two type - a wide chip model in which the chip has a large width and encapsulation layer covers only the chip, and a narrow chip model in which the chip covers both the substrate and the chip with smaller width than the substrate. In the wide chip model where the external load acts directly on the chip, the encapsulation layer with high stiffness enhanced the crack resistance of the film chip as the thickness of the encapsulation layer increased regardless of loading conditions. In contrast, the encapsulation layer with high stiffness reduced the crack resistance of the film chip in the narrow chip model for the case of external tensile strain loading. This is because the external load is transferred to the chip through the encapsulation layer and the small load acts on the chip for the weak encapsulation layer in the narrow chip model. When the bending moment acts on the narrow model, thin encapsulation layer and thick encapsulation layer show the opposite results since the neutral axis is moving toward the chip with a crack and load acting on chip decreases consequently as the thickness of encapsulation layer increases. The present study is expected to provide practical design guidance to enhance the durability and fracture performance of the silicon chip in the multilayer package with encapsulation layer.