• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.447-447
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• 2023

Soil organic carbon (SOC) is a critical indicator of soil fertility. Its importance in maintaining ecological balance has received widespread attention. However, global temperatures have risen by 0.8℃ since the late 1800s due to human-induced greenhouse gas emissions, resulting in severe disruptions in SOC dynamics. To study the impacts of temperature variations on SOC and soil respiration, we used the Soil Carbon and Landscape co-Evolution (SCALE) model, which was capable of estimating the spatial distribution of soil carbon dynamics. The study site was located at Heshan Farm (125°20'10.5"E, 49°00'23.1"N), Nenjiang County in Heilongjiang Province, Northeast China. We validated the model using observed soil organic carbon and soil respiration in 2015 and achieved excellent agreement between observed and modeled variables. Our results showed considerable influences of temperature increases on SOC and soil respiration rates at both erosion and deposition areas. In particular, changes in SOC and soil respiration at the deposition area were greater than at the erosion area. Our study highlights that the impacts of temperature elevations are considerably dependent on soil erosion and deposition processes. Thus, it is important to implement effective soil conservation strategies to maintain soil fertility under global warming.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.87-87
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• 2023

The impact of climate change on typhoons is a major concern in East Asia, especially due to the destructive effects of heavy rainfall on society and the economy, as many megacities are located along coastal regions. Although observations suggest significant changes in typhoon heavy rainfall, the extent to which anthropogenic forcing contributes to these changes has yet to be determined. In this study, we demonstrate that anthropogenic global warming has a substantial impact on the observed changes in typhoon heavy rainfall in the western North Pacific region. Observation data indicates that, in general, typhoon heavy rainfall has increased (decreased) in coastal East Asia (tropical western North Pacific) during the latter half of the 20th century and beyond. This spatial distribution is similar to the "anthropogenic fingerprint" observed from a set of large ensemble climate simulations, which represents the difference between Earth systems with and without human-induced greenhouse gas emissions. This provides evidence to support the claim that the significant increase in the frequency of typhoon heavy rainfall along coastal East Asia cannot be solely explained by natural variability. In addition, our results indicate that the signal of the "anthropogenic fingerprint" has been increasing rapidly since the mid-1970s and departed from natural variability in the early 2000s, indicating that the regional summer climate has already crossed the tipping point.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.123-133
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• 2022

Cultural tourism is a form of tourism based on national cultural identity with the participation of the community to preserve and promote traditional cultural values. Cultural tourism is a trend of many countries in the world, it is suitable for the context in the Mekong Delta, Vietnam. Cultural tourism is very good for poverty reduction activities, so it is considered a direction of socio-economic development. The study's goal is to look at the factors that influence the development of cultural tourism in Vietnam's Mekong Delta. Survey findings from 1275 survey samples in the Mekong Delta, Vietnam, were used to compile the research data. Cronbach's Alpha reliability coefficient; exploratory factor analysis EFA; CFA confirmatory factor; SEM linear regression analysis are used to analyze and assess scales using SPSS 20, AMOS 24 software. According to the findings of the SEM model study, there are six factors that influence the development of cultural tourism in the Mekong Delta of Vietnam, including policy development tourism, infrastructure for tourism, human resources for tourism, tourism resources, geographic location, tourism products, and services. A discussion on administration is proposed to the development of cultural tourism in the Mekong Delta, Vietnam, based on the research findings.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.145-145
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• 2021

Water distribution networks (WDNs) are designed to satisfy water requirement of an urban community. One of the central issues in human history is providing sufficient quality and quantity of water through WDNs. A WDN consists of a great number of pipelines with different ages, lengths, materials, and sizes in varying degrees of deterioration. The available annual budget for rehabilitation of these infrastructures only covers part of the network; thus it is important to manage the limited budget in the most cost-effective manner. In this study, a novel pipe replacement scheduling approach is proposed in order to smooth the annual investment time series based on a life cycle cost assessment. The proposed approach is applied to a real WDN currently operating in South Korea. The proposed scheduling plan considers both the annual budget limitation and the optimum investment on pipes' useful life. A non-dominated sorting genetic algorithm is used to solve a multi-objective optimization problem. Three decision-making objectives, including the minimum imposed LCC of the network, the minimum standard deviation of annual cost, and the minimum average age of the network, are considered to find optimal pipe replacement planning over long-term time period. The results indicate that the proposed scheduling structure provides efficient and cost-effective rehabilitation management of water network with consistent annual budget.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.45-57
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• 2023

To assess land subsidence estimation and preparedness in the Geum River basin, this study applied GIS techniques and identified six key areas. The Geum River basin has experienced an increase in heavy rainfall since late 2010, and four study areas have shown an increase in groundwater levels. Land subsidence primarily occurred from June to September, with higher rainfall years in 2020 and 2023. Approximately 83.6% of land subsidence in Chungcheongbuk-do province occurred in Cheongju-si, mainly attributed to aging sewage pipes. The regions experiencing population growth have likely led to the construction of underground infrastructures and sewer pipes. Thus, it is considered that various factors, including sewage pipe leaks, precipitation, slope gradient, low drainage density, and groundwater level fluctuations, have contributed to land subsidence. Improving land subsidence estimation involves incorporating additional natural factors and human activities.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.107-110
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• 2008

Tropical fire ant, Solenopsis geminata (Fabricius) is distributed over the tropical and temperate areas. It is a polyphagous pest attacking to various plant and causes the pain to the people doing outdoor work. So it is known for a hygienic pest to human being, especially the people doing outdoor activities. It can cause severe pain to human, even with just a bite. Of particular concern is the possibility of its settlement in this country, if it invade to the farmlands and/or forests of Jeju Island and southern part in Korea. It is listed as a regulated pest in Plant Quarantine Act of Korea. This ant is usually imported through a ship and early settled in the port area where it is already distributed. Recently its distribution is rapidly spreading into Southeast Asia and southern part of China. In Korea, it was detected the one time in 1990s, but was detected the ten times from 2000 to 2006 by an imported plant quarantine process. Therefore, we would like to provide some information on the species, including morphology, distribution, host plant, damaged symptom and its general bionomics, which will be useful data for plant quarantine process and control.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.160-173
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• 2005

In this study, we had tried to present a plan for improving the actual conditions of practical utilization of teaching material for 6th grade science developed by Ministry of Education & Human Resources Development and distributed to all elementary schools in Korea. Also we presented ways of better utilization of the teaching material after investigating the actual conditions of practical utilization. A survey was made to investigate and collect all data in the major metropolitan cities, the Kangwon, Chungcheong, Honam, and Kyeongsang area, respectively. We surveyed 316 6th grader teachers to investigate the actual conditions of distribution and utilization of teaching material as a general research. In addition, we surveyed 46 teachers to investigate the organization and content of teaching material as a particular research. The results are as follows. First, the teaching material was not approximately transmitted and kept to 6th grader teachers. Second, the utilization guide was not made. Third, it was reported that the thematic divisions of teaching material was a strong point, but the less detailed experiment manual was a weak point. Fourth, the consideration of content difficulties and simplicity was necessary to improve the material. Fifth, additional items should be included in the introductory presentation, convenience of reorganization, activity material causing learning interest, guidance of substitution experiment, and more concrete notice of experiment activity. Finally, there were positive responses of more than 4.0 point of Likert scale (1 to 5 point scale) in detail investigations of thematic items, which could have possibility that the teaching material was helpful to elementary school science field.

• Journal of Preventive Medicine and Public Health
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• v.57 no.4
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• pp.356-369
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• 2024

Objectives: The objective of this study was to explore healthcare providers' experiences in managing the coronavirus disease 2019 (COVID-19) pandemic and its impact on healthcare services. Methods: A qualitative study was conducted with 34 healthcare professionals across 15 districts in Bangladesh. Among the participants, 24 were health managers or administrators stationed at the district or upazila (sub-district) level, and 10 were clinicians providing care to patients with COVID-19. The telephone interviews were conducted in Bangla, audio-recorded, transcribed, and then translated into English. Data were analyzed thematically. Results: Most interviewees identified a range of issues within the health system. These included unpreparedness, challenges in segregating COVID-19 patients, maintaining isolation and home quarantine, a scarcity of intensive care unit beds, and ensuring continuity of service for non-COVID-19 patients. The limited availability of personal protective equipment, a shortage of human resources, and logistical challenges, such as obtaining COVID-19 tests, were frequently cited as barriers to managing the pandemic. Additionally, changes in the behavior of health service seekers, particularly increased aggression, were reported. The primary motivating factor for healthcare providers was the willingness to continue providing health services, rather than financial incentives. Conclusions: The COVID-19 pandemic presented a unique set of challenges for health systems, while also providing valuable lessons in managing a public health crisis. To effectively address future health crises, it is crucial to resolve a myriad of issues within the health system, including the inequitable distribution of human resources and logistical challenges.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.129-137
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• 2008

As the use of the internet increases, the distribution of spam mail has also vastly increased. The email's main use was for the exchange of information, however, currently it is being more frequently used for advertisement and malware distribution. This is a serious problem because it consumes a large amount of the limited internet resources. Furthermore, an extensive amount of computer, network and human resources are consumed to prevent it. As a result much research is being done to prevent and filter spam. Currently, research is being done on readable sentences which do not use proper grammar. This type of spam can not be classified by previous vocabulary analysis or document classification methods. This paper proposes a method to filter spam by using the subject of the mail and N-GRAM for indexing and Bayesian, SVM algorithms for classification.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.129-138
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• 2021

Today we are getting a lot of information and various activities on our website through the internet. These websites are maintained by individuals or by website specialists. The basic method is to change the files that make up the running website. Changing the entire file in this process takes a long time and changes the files that do not need to be changed, so the efficiency is greatly reduced. When only the files that need to be changed are changed, it takes a lot of effort as a person must manually search each path to check the files and change the files one by one. To solve this problem, automatic distribution systems were developed. Additional resources and learning are required, resulting in additional cost, time and labor. Therefore, in this paper, we propose an automatic update system to minimize resource consumption by using the resources and technologies of the existing website. The proposed system does not require learning new skills. This aims to improve reliability and reduce time compared to human work.