• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.69-78
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• 2009

In order to improve water quality of upper watershed of Paldang reservoir, it is necessary to evaluate non-point source pollution loads and identify critical watershed pollution sources. A GIS based Soil and Water Assessment Tool was applied to evaluate model application and reliability, estimate NPS pollution load, identify critical watershed by NPS pollution sources, and suggest various best management practices for Kyongan Stream watershed. Yearly NPS pollution loads were estimated 30.0% SS, 60.1% TN and 35.4% TP, respectably. The watershed pollution load is mainly decided by precipitation condition and SS and nutrients load have a significant regression relationship. Based on 10-year average yearly NPS pollution load, critical sub-watersheds were identified. The No. 5 and 17 which have lots of relatively intensive agricultural fields and scattered industrial area were vary critical sub-watersheds and under more intensive pollution load. In order to control critical watershed, watershed best management practices such as scientific fertilizer, contour farming and parallel terrace, transferring the sloppy farmland to grass or forest and constructing a buffer zone, and constructing wetlands and retention ponds will be applied. Overall the SWAT model can be efficiently used for identification of critical sub-watersheds in order to develop a priority watershed management plan to reduce water pollutions.

• Journal of The Korean Digital Architecture Interior Association
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• v.9 no.3
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• pp.69-76
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• 2009

The importance of efficient construction site management has been growing as the amount of construction information increases which is used in the growing construction site. Accordingly in this study, we are trying to find out the application situation and possibility of BIM through theoretical examination and domestic & overseas case study of BIM and we are trying to suggest the way of efficient construction site management formulation through implementation phase-oriented and cooperation entity-oriented analysis in the construction site. We found out that it was possible to minimize time loss and financial loss by visualizing 2D drawings through 3D modeling of target building by applying BIM and that it was possible to improve accuracy of budget planning with quantitative information of 3D model, to plan construction process with more confidence due to accurate architectural information of drawings and quantitative information, and to manage cost and quality through process management based on construction information acquired by BIM including object information by part. It is concluded that we can improve efficiency of construction management between field and each cooperating entity by integrating and linking BIM information through this process.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.952-961
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• 2016

The objective of this study is to examine the effects of consumer beliefs regarding three food certifications on their behavioral intention and the behavioral intention biases to purchase (purchasing intention biases) certified agricultural products as predicted by a subjective probability model. The food certifications used for this study are 'Organic food', 'Traceability system of food products,' and 'Hazard Analysis Critical Control Point (HACCP)'. Tofu (bean curd) was selected as being representative of agricultural food products, for the purposes of this study. In 2016, we surveyed 243 consumers regarding the strength of their belief regarding their prior beliefs relative to each certification, as well as the strength of their intention to purchase certified tofu based on their belief strengths for this study. The study resulted in the following findings: Firstly, consumers hold more than two different prior beliefs for each of the three certifications included in this study. Consumers' prior beliefs regarding these certifications have an impact on their consideration as to whether they plan to buy those certified agricultural products. Secondly, consumers try to persuade themselves to ensure that their particular belief about the product's certification could lead to a purchasing decision regarding that agricultural product.

• ETRI Journal
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• v.27 no.6
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• pp.759-767
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• 2005

This research is to substantially analyze the economic value of portable Internet (WiBro), WCDMA High Speed Downlink Packet Access (HSDPA), WiBro+VoIP, and WiBro+DMB regarded as the next generation of broadcasting. Based on the empirical analysis of economic values, we provide the optimal paths of converged communications and broadcasting services related to WiBro. 1,000 Internet users in the Seoul and Gyeonggi areas were surveyed in their homes. The collected survey was calculated as an accurate economic value distribution for relevant services, and the average and mean were taken using a parametric logit model, semi-parametric Spike model, and nonparametric Turnbull and Kernel estimations in order to analyze the contingent economic value of the amount offered to the subjects of the analysis. The contingent value analysis results varied slightly according to the different methodologies; however, all showed the following common features. The economic value of WiBro, Internet-based WCDMA, VoIP, and DMB with WiBro appeared to be similar. Therefore, if WiBro and WCDMA (HSDPA) form a competitive relationship, the types of bundled services offered as portable Internet service and the supply point of such bundled services are expected to emerge in a strategic plan for stimulating service markets and the prior occupation of the market.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.2
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• pp.51-58
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• 2016

The importance of SW education is being stressed recent days, and the App Inventor is getting attention as a tool of SW education. In this study, I have developed an app Inventor instruction model, which is based on the Design Based Learning and integrated with elements of computational thinking. And I taught the student to apply this model. and then analyzed the app production process and the changes of student. In developing the app, students defined the problem and made a plan to resolve them. And this student had have a sense of accomplishment and self-confidence through practical experience to implement it in their own source code.

• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.48-60
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• 2021

Following the global air-traffic market growth outlook, urgency of technical development is needed in responding to changes in the international air-traffic management paradigm and to prepare technology securing and spreading strategies, which are consistent with systematic aviation weather service policies and evolution direction. Although air traffic has decreased significantly due to COVID-19, normalcy is expected from 2024, as announced by IATA. According to the future air transportation market outlook and development trends of related technologies, Korea has established and implementing the next-generation air transportation system construction plan(NARAE) to secure international competitiveness and leadership in the future. Therefore, this paper describes the technical, economic background and requirements of numerical model-based aviation weather R&D projects for successful implementation of domestic NARAE plans and providing aviation safety and air traffic service efficiency. Furthermore, we proposed numerical-model-based technology development content, strategies and detailed load-map.

• Journal of Astronomy and Space Sciences
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• v.37 no.4
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• pp.229-236
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• 2020

There has been increasing necessity of more precise prediction and measurements of aviation radiation in Korea. For our air crew and passengers' radiation safety, we develop our own radiation prediction model of KREAM. In this paper, we validate the KREAM model based on comparison with Liulin observations. During early three months of this year, we perform total 25 experiments to measure aviation radiation exposure using Liulin-6K in commercial flights. We found that KREAM's result is very well consistent with Liulin observation in general. NAIRAS shows mostly higher results than Liulin observation, while CARI-6M shows generally lower results than the observations. The percent error of KREAM compared with Liulin observation is 10.95%. In contrast, the error for NAIRAS is 43.38% and 22.03% for CARI-6M. We found that the increase of the altitude might cause sudden increase in radiation exposure, especially for the polar route. As more comprehensive and complete analysis is required to validate KREAM's reliability to use for the public service, we plan to expand these radiation measurements with Liulin and Tissue Equivalent Proportional Counter (TEPC) in the near future.

• Communications for Statistical Applications and Methods
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• v.28 no.4
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• pp.393-410
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• 2021

The Korean Long-Term Care Insurance (K-LTCI) provides financial support for long-term care service to people who need various types of assistance with daily activities. As the number of elderly people in Korea is expected to increase in the future, the demand for long-term care insurance would also increase over time. Projection of future expenditure on K-LTCI depends on the number of beneficiaries within the grading system of K-LTCI based on the test scores of applicants. This study investigated the suitability of mixture distributions to the model K-LTCI score distribution using recent empirical data on K-LTCI, provided by the National Health Insurance Service (NHIS). Based on the developed mixture models, the number of beneficiaries in each grade and its variability under the current grading system were estimated by simulation. It was observed that a mixture model is suitable for K-LTCI score distribution and may prove useful in devising a funding plan for K-LTCI benefit payment and investigating the effects of any possible revision in the K-LTCI grading system.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.132-132
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• 2021

Access to accurate spatial precipitation in many hydrological studies is necessary. Existence of many mountains with diverse topography in South Korea causes different spatial distribution of precipitation. Rain gauge stations show accurate precipitation information in points, but due to the limited use of rain gauge stations and the difficulty of accessing them, there is not enough accurate information in the whole area. Weather radars can provide an integrated precipitation information spatially. Despite this, weather radar data have some errors that can not provide accurate data, especially in heavy rainfall. In this study, some location-based variable like aspect, elevation, plan curvature, profile curvature, slope and distance from the sea which has most effect on rainfall was considered. Then Automatic Weather Station data was used for spatial training of variables in each event. According to this, K-fold cross-validation method was combined with Adaptive Neuro-Fuzzy Inference System. Based on this, 80% of Automatic Weather Station data was used for training and validation of model and 20% was used for testing and evaluation of model. Finally, spatial distribution of precipitation for 1×1 km resolution in Gwangdeoksan radar station was estimates. The results showed a significant decrease in RMSE and an increase in correlation with the observed amount of precipitation.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.398-412
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• 2023

The Korean government is actively promoting the hydrogen industry as a key driver of economic growth. This commitment is evident in the 2019 hydrogen economy activation roadmap and the 2021 basic plan for hydrogen economy implementation. This study quantitatively analyzes the economic impact of the hydrogen economy using input-output analysis based on the Bank of Korea's 2019 input-output table, projecting its size by 2050. Four parts dealt with production-inducing, value-added creation, employment-inducing, and wage-inducing based on a demand-driven model. The results reveal that transportation had the most remarkable economic effect throughout the hydrogen economy, and production was the least. The hydrogen economy is projected to reach 71.2 trillion won by 2050.