• Korean Journal of Remote Sensing
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• v.40 no.1
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• pp.9-18
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• 2024

Small streams, despite their rich ecosystems, face challenges in vegetation assessment due to the limitations of traditional, time-consuming methods. This study presents a groundbreaking approach, combining unmanned aerial vehicles(UAVs), convolutional neural networks(CNNs), and the vegetation differential vegetation index (VDVI), to revolutionize both assessment and management of stream vegetation. Focusing on Idong Stream in South Korea (2.7 km long, 2.34 km² basin area)with eight diverse revetment methods, we leveraged high-resolution RGB images captured by UAVs across five dates (July-December). These images trained a ResNeXt101 CNN model, achieving an impressive 89% accuracy in classifying vegetation cover(soil,water, and vegetation). This enabled detailed spatial and temporal analysis of vegetation distribution. Further, VDVI calculations on classified vegetation areas allowed assessment of vegetation vitality. Our key findings showcase the power of this approach:(a) TheCNN model generated highly accurate cover maps, facilitating precise monitoring of vegetation changes overtime and space. (b) August displayed the highest average VDVI(0.24), indicating peak vegetation growth crucial for stabilizing streambanks and resisting flow. (c) Different revetment methods impacted vegetation vitality. Fieldstone sections exhibited initial high vitality followed by decline due to leaf browning. Block-type sections and the control group showed a gradual decline after peak growth. Interestingly, the "H environment block" exhibited minimal change, suggesting potential benefits for specific ecological functions.(d) Despite initial differences, all sections converged in vegetation distribution trends after 15 years due to the influence of surrounding vegetation. This study demonstrates the immense potential of UAV-based remote sensing and CNNs for revolutionizing small-stream vegetation assessment and management. By providing high-resolution, temporally detailed data, this approach offers distinct advantages over traditional methods, ultimately benefiting both the environment and surrounding communities through informed decision-making for improved stream health and ecological conservation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.3
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• pp.139-143
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• 2005

Several methods have been proposed to mitigate the market power in foreign electricity markets. In this paper, Hirfindahl-Hirschman Index(HHI) and supply margin assessment(SMA) are compared based upon the Korean future markets. The results show that SMA is better than HHI to estimate market power because it can reflect congestion and capacity reserve effectively.

• The Korean Journal of Applied Statistics
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• v.11 no.1
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• pp.13-28
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• 1998

Corrent measurement system assessment is crucial in helping improve process or quality. In this article, we would like to apply several methods of measurement system assessment in statistical process control. Specifically, focus is on accuracy, precision (both repeatability and reproducibility included), and stability of the measurement process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1081-1090
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• 2015

This work proposes a theoretic framework for the performance assessment of an access point in the IP network that accommodates MD (Machine Data) and HD (Human Data). First, we investigate typical resource allocation methods in LTE for MD and HD. After that we carry out a Max-Min analysis about the surplus and deficiency of network resource seen from MD and HD. Finally, we evaluate the performance via numerical experiment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.304-316
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• 2021

Objectives: By comparing and analyzing the legal system for risk assessment in South Korea with other advanced countries, the study is designed to identify the key elements of risk assessment and seek improvement measures while focusing on solutions to the execution of risk assessment violations. Methods: The study started with an awareness of the need to improve the legislation on the risk assessment of businesses in Korea. In order to reflect this problem consciousness in Korea's industrial safety and health legislation, risk assessment legislation in Japan, Britain, Germany, and Korea was analyzed in comparative terms through the literature. Results: Unlike the other advanced countries, the concept of risk assessment is defined in Korea in a broad sense that includes measures to reduce risk, and risk assessment in the manufacturing and design stages is not institutionalized. In the case of worker participation, there is a problem regarding effectiveness. It is problematic that compared to the other foreign countries there is a possibility that general risk assessment will be neutralized because it is recognized as a uniform general risk assessment for a particular risk assessment, as well as inadequate risk assessment. Conclusions: The areas diagnosed with problems compared to the legislation in other advanced countries should be improved by revising laws and administrative rules and supplementing the explanatory guidelines, etc. by referring to the legislation of these countries. In particular, the issue of enforcement for violations of risk assessment must be improved in order to ensure the effectiveness of risk assessment.

• Journal of Environmental Impact Assessment
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• v.10 no.1
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• pp.59-71
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• 2001

This study aims to propose a determinant model to select a method on calculating weight of each indicator for environmental evaluation. According to analyzing and comparing with three types of methods for calculating weights which are usually used to evaluate environment with indicators, the weights which were obtained by each type were all different from each other. This means that a differential weighting method must be applied to each of environmental evaluation studies. Therefore, a determinant model is required to determine weight-calculating methods. Three types of weighting methods, such as weighting by importance degree, weighting by eigen-value and weighting by analytic hierarchy process, were compared. Under the necessity, a determinant model was drawn for selecting a compatible method to calculate weights of indicators in environmental evaluation.

• Environmental Analysis Health and Toxicology
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• v.24 no.3
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• pp.261-270
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• 2009

To make measurable regulatory decisions of chemicals, it is necessary to consider their effect on the human health and ecosystem. In principle, this is based on relevant toxicity studies conducted by accepted guidelines. However, current regulatory programs in various countries confront challenges related to risk assessment of large numbers of chemicals within the restricted resources and time. Therefore there is a need for more efficient approach to limit the number of tests to be conducted. This promotes the development of powerful nontesting methods (e.g. (Q)SARs) and permits to use the predicted data for regulatory purpose. In this article, current status of non-testing methods in various chemical regulatory programs was reviewed in terms of their application and research activity on them. Finally, their usefulness associated with development of domestic regulatory program was suggested.

• Proceedings of the Korea Society of Design Studies Conference
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• 2004.05a
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• pp.194-195
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• 2004

• The Journal of the Korean dental association
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• v.49 no.1
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• pp.16-21
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• 2011

Now it is time to move from the scientific basis of CAMBRA into practical methods for dentists to the incorporate concepts into practice. The aim of this article is to provide a clinical guideline for assessment of caries risk and for application for growing children.

• Journal of Korea Port Economic Association
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• v.27 no.3
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• pp.65-90
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• 2011

Private stevedoring companies are leasing and operating the container terminals of the Busan Port. The total amount of lease fees private stevedoring companies paid in 2010 reached 161 billion wons, an approximately 66 percent of the total revenue of the Busan Port Authority(BPA). In other words, lease fees are the most important revenue source for BPA. However, the lease fee assessment system of Busan container terminals goes against the principle of equity due to different assessment methods and criteria adopted by each container terminal. Therefore, the purpose of the study is to analyze the systematic problems of the lease fee assessment system that is used at Busan container terminals, and propose a new standardized scheme with a case study on the new system. In order to standardize the assessment system, the assessment methods need to be simplified by using the Discounted Cash Flow(DCF) method. In addition, the assessment criteria such as assessment duration, discount rates, price indexes, estimated container throughputs, sales unit price per TEU, operation costs, including labor costs, need to be standardized as well. The new standardized assessment system can be applied to estimate lease fees for new terminals. However, for existing terminals to run the new system, factors such as assessment duration, discount rates, price indexes, estimated container throughputs, investment and re-investment costs, and maintenance & repair costs of the new system should be changed slightly.