• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.2
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• pp.113-122
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• 2021

Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km² in 1998 to 162.6 km² in 2007, and 267.2 km² in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.6
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• pp.163-172
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• 2021

To specify a formal semantics for a programming language is to do a significant part for design, standardization and translation of it. The Python is popular and powerful, it is necessary to do research for a formal semantics to specify a static and dynamic semantics for Python clearly in order to design a similar language and do an efficient translation. This paper presents the Action Equation 2.0 that specifies a formal semantics for Python to change and update Action Equation. To measure the execution time for Python programs, we implemented the semantic structure specified in Action Equation 2.0 in Java, and prove through simulation that Action Equation 2.0 is a real semantic structure that can be implemented. The specified Action Equation 2.0 is compared to other descriptions, in terms of readability, modularity, extensibility, and flexibility and then we verified that Action Equation 2.0 is superior to other formal semantics.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.4
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• pp.192-199
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• 2022

With the advent of autonomous ships, it is emerging as one of the very important issues not only to operate with a minimum crew or unmanned ships, but also to secure the safety of ships to prevent marine accidents. On-site inspection of the hull is mainly performed by the inspector's visual inspection, and video information is recorded using a small camera if necessary. However, due to the shortage of inspection personnel, time and space constraints, and the pandemic situation, the necessity of introducing an automated inspection system using artificial intelligence and remote inspection is becoming more important. Furthermore, research on hardware and software that enables the automated inspection system to operate normally even under the harsh environmental conditions of a ship is absolutely necessary. For automated inspection systems, it is important to review artificial intelligence technologies and equipment that can perform a variety of hull failure detection and classification. To address this, it is important to classify the hull failure. Based on various guidelines and expert opinions, we divided them into 6 types(Crack, Corrosion, Pitting, Deformation, Indent, Others). It was decided to apply object detection technology to cracks of hull failure. After that, YOLOv5 was decided as an artificial intelligence model suitable for survey and a common hull crack dataset was trained. Based on the performance results, it aims to present the possibility of applying artificial intelligence in the field by determining and testing the equipment required for survey.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.235-243
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• 2022

In this paper, in the case of an inertial navigation system, the posture estimation error in the initial alignment due to vertical deflection is analyzed. Posture estimation error due to DOV was theoretically analyzed based on the speed and posture error of INS. Simulations were performed to verify the theoretical grinding, and the results were in good agreement. For example, in the case of η=20", an alignment error of ϕ_N=0.00287°, ϕ_U=0.00196° occurred, and in the case of 𝜉=20", an error of ϕ_E= -0.00286° occurred. Through this, it was confirmed that the vertical posture error caused by the DOV occurred as a coupling characteristic of the INS posture error. It has been shown that an additional posture error may occur due to the DOV, which was not considered in the existing INS alignment, which means that correction for the DOV must be considered when applying high-precision INS.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1115-1125
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• 2022

Nuclear power plant (NPP) is currently considered as one of the most reliable power sources. However, 182 of them are considered decommissioned and inactive including the one in Bataan, Philippines. The aim of this study was to investigate the acceptance of the reopening of Bataan Nuclear Power Plant (BNPP) by integrating the Theory of Planned Behavior and Protection Motivation Theory. A total of 815 Filipinos answered an online questionnaire which consisted of 37 questions. The Structural Equation Modeling (SEM) indicated that knowledge towards nuclear power plants was the key factor in determining people's acceptance towards NPP reopening. In addition, knowing the benefits would lead to positive perceived behavioral control (PBC) and attitude towards intention. Results showed that PBC and attitude are mediators towards the acceptance of people regarding the reopening of BNPP. If an individual's knowledge gravitates towards the perceived risk, then this can lead to the negative acceptance of the NPP reopening. On the other hand, if an individual's knowledge gravitates towards the perceived benefits, then this will lead to positive acceptance. This study is the first study that explored the acceptance of the reopening BNPP. Finally, the study's model construct would also be very beneficial for researchers, government, and even private sectors worldwide.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.7-14
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• 2022

COVID-19 has caused a global disturbance, increased anxiety, and panic, eliciting diverse reactions. While its cure has not been discovered, new infection cases and fatalities are being recorded daily. The focus of the present study was to analyze the reaction of gifted undergraduate students on social media during the quarantine period of the COVID-19. A special group of gifted students, who joined the program of attracting and nurturing talents at the University of Jeddah, University students as were the target sample of this study. To analyze online reactions during the pandemic; the choice of university students was arrived at as they are perceived to be gifted academically. Hence, the analysis of the impacts on their behavior on social media use is imperative. This study presented accurate and consistent data on the effects of social media using Twitter platforms on gifted students during the quarantine occasioned by the COVID-19 pandemic. The behavior of learners due to during the use of social media was extensively explored and results analyzed. The study was carried out between April and May 2020 (quarantine period in Saudi Arabia) to establish whether the online behavior of gifted students reflects positive or negative feelings. The methods used in conducting this study the research were online interviews and scraping participants' Twitter accounts (where most of the online activities and studies take place). The study employed the Activity theory to analyze the behavior of gifted students on social media. The sample size used was 60 students, and the analysis of their behavior was based on Activity theory Overall, the results showed proactive, positive behavior for coping with a challenging situation, educating society, and entertaining. Finally, this study recommends investing in gifted students due to their valuable problem-solving skills that can help handle global pandemics efficiently.

• Nutrition Research and Practice
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• v.16 no.6
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• pp.755-764
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• 2022

BACKGROUND/OBJECTIVES: Cardiovascular diseases (CVDs) are the leading cause of death in Koreans, and eating habits, including diet quality, are among the etiologies of these diseases. Recently, various studies on regional health disparities have been conducted. However, there are limited studies on their relationship with nutritional factors. This study aimed to identify the magnitude of regional disparities in diet quality and prevalence of CVD in Korean adults. SUBJECTS/METHODS: This study included 17,646 participants aged ≥ 20 years from the 7^th (2013-2016) Korean National Health and Nutrition Examination Survey. Participants were classified into four groups based on their residential areas: City 1, City 2, City 3, and non-city. Demographic characteristics, health-related factors, body mass index (BMI), metabolic syndrome index, diet quality, and CVD prevalence were evaluated. RESULTS: In terms of demographic characteristics, age (P < 0.001), marital status (P < 0.001), educational level (P < 0.001), and income (P < 0.001) were lower in the non-city category. Health-related factors such as monthly drinking rate (P < 0.01) and mental stress (P < 0.05) were the highest in City 1 and lowest in the non-city group. Conversely, the current smoking rate (P < 0.05), BMI (P < 0.05), and prevalence of metabolic syndrome (P < 0.001) were the highest in the non-city group (P < 0.05). The non-city group also had the highest prevalence of CVDs (35.6%). This group had the lowest diet quality index (68.36 ± 0.22, P < 0.01), caused by low intake of fruit and calcium, a lack of sodium moderation, and an overall imbalance in the macronutrient and fatty acid ratio. When the diet quality index was increased by 1, the odds ratio for the prevalence of CVDs was reduced by 0.991 (P < 0.001), but this was not the case in all regions. CONCLUSIONS: This study provides useful information and data in identifying and resolving the regional health disparities related to CVD prevalence and implementation of public health nutrition systems.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.12
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• pp.461-468
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• 2022

Development of the big data industry, the cases of providing data utilization services on digital platforms are increasing. In this regard, research in data-related fields is being conducted to apply the FAIR principle that can be applied to the assessment of (meta)data quality, service, and function to data quality evaluation. Especially, the European Open Data Portal applies an assessment model based on FAIR principles. Based on this, a data maturity assessment is conducted and the results are disclosed in reports every year. However, public data portals do not conduct data maturity evaluations based on metadata. In this paper, we propose and evaluate a new model for data maturity evaluation on a big data platform built for multiple domestic public data portals and data transactions, FAIR principles used for data maturity evaluation in Europe's open data portals. The proposed maturity evaluation model is a model that evaluates the quality of public data portal datasets.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.12
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• pp.437-444
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• 2022

Recently, research on mobile edge services has been conducted to handle computationally intensive and latency-sensitive tasks occurring in wireless networks. However, MEC, which is fixed on the ground, cannot flexibly cope with situations where task processing requests increase sharply, such as commuting time. To solve this problem, a technology that provides edge services using UAVs (Unmanned Aerial Vehicles) has emerged. Unlike ground MEC servers, UAVs have limited battery capacity, so it is necessary to optimize energy efficiency through load balancing between UAV MEC servers. Therefore, in this paper, we propose a load balancing technique with consideration of the energy state of UAVs and the mobility of vehicles. The proposed technique is composed of task offloading scheme using genetic algorithm and task migration scheme using Q-learning. To evaluate the performance of the proposed technique, experiments were conducted with varying mobility speed and number of vehicles, and performance was analyzed in terms of load variance, energy consumption, communication overhead, and delay constraint satisfaction rate.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.12
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• pp.429-436
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• 2022

Temporary files are generated when the Hash Join is performed on tables larger than the memory. During the join process, each temporary file is deleted sequentially after it completes the I/O operations. This paper reveals for that the fallocate system call and file deletion-related trim options significantly impact the hash join performance when temporary files are managed on SSDs rather than hard disks. The experiment was conducted on various commercial and research SSDs using PostgreSQL, a representative open-source database. We find that it is possible to improve the join performance up to 3 to 5 times compared to the default combination depending on whether fallocate and trim options are used for temporary files. In addition, we investigate the write amplification and trim command overhead in the SSD according to the combination of the two options for temporary files.