• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4280-4288
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• 2024

This research article introduces a study regarding the uncertainties treatment during severe accidents for Pressurized Heavy Water Reactors (PHWRs). The present study is focused upon the unmitigated Station BlackOut (SBO) accident analysis for a CANada Deuterium Uranium (CANDU) type reactor emphasizing the impact of the uncertainties treatment on the relevant key timings of the SBO accident progression through different approaches for the uncertainty parameters' Probabilistic Distribution Functions (PDFs). A comparison between the sensitivity analysis results is provided in the present research study. The uncertainty analysis is performed with the RELAP/SCDAPSIM code with the Integrated Uncertainty Analysis (IUA) package from the code. Results from the research would support the advancements on the best-practices for uncertainty analyses with respect to the parameter's uncertainties distribution functions. Data dispersion is a key element for the realistic quantification of uncertainties in nuclear power plant safety analyses, including severe accidents.

• Journal of Soil and Groundwater Environment
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• v.25 no.1
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• pp.84-94
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• 2020

Jeju Island is seeking reliable ways to secure alternative water resources using rainwater in order to conserve and manage its groundwater as sustainable water resources. The purpose of this study is to investigate the rainwater storage capability of small-size storage facilities installed at farmhouses in Uigwi and Wimi of Namwon-eup region. The rainwater outflows from the storage facilities in rain events were analyzed. The appropriate size of rainwater utilizing facilities are suggested to be about 5,800 ㎥ in Uigwi area and 4,900 ㎥ in Wimi area based on the calculation from the rainfall frequency and runoff amounts. If those facilities are put into operation in Uigwi and Wimi area, it is estimated approximately 32.3 and 11.5% of total agricultural water can be supplied by the facilities. Wimi area showed low rainwater usage because of less number of facilities relative to the size of farm areas and less intensive underground water usage. It is analyzed that more than 55% of agricultural water can be supplied by rainwater if 70 facilities without the rainwater facilities are connected to the rainwater utilizing facilities.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.11-18
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• 2012

This study was investigated agricultural water supply system of major agricultural waterway for Gimje canal, Jeongeup canal, Dongjin river conduit of Dongjin river basin. Furthermore, this result will be used for water resources and agricultural demand in Saemangeum reclaimed arable land. Annual precipitation for 5 years in Dongjin river basin was 1,311.7mm. The average discharges in Dongjin river basin was $1,390{\times}10^6\;m^3$ and $1,516{\times}10^6\;m^3$ and $744{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Also, annual average amount of water resources was 1,861${\times}10^6\;m^3$ and $2,279{\times}10^6\;m^3$ and $1,227{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Dongjin river basin water system for the analysis of agricultural water in water resources, runoff, agricultural water demand and usage surveys were analyzed, resulting in the total amount of water due to precipitation of the watershed of the $12.3{\times}10^9\;m^3$ ~$22.8{\times}10^9\;m^3$ and Dongjin River basin in waters flowing discharge is $7.4{\times}10^9\;m^3$~$16.1{\times}10^9\;m^3$, agricultural water demand and usage of each of $6.8{\times}10^9\;m^3$~$6.9{\times}10^9\;m^3$ and $4.9{\times}10^9\;m^3$~$7.1{\times}10^9\;m^3$ compared to the agricultural water demand was more likely. Agricultural water supply system in Dongjin river basin is complex because of devided branches to the main canal and branch canal. In this process, accurately assessment of water usage is very difficult. Therefore, systematic management of water resources and supply of agricultural water supply system to use the terms of the complexity and diversity by considering the appropriate level of agricultural water management systems will be needed. As a result of this study, it can be used water resources assessment in quantity, rational usefulness and basic planning of water resources development for water distribution.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.339-347
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• 2015

Differences in characteristics of flora and environmental factors of geomorphology, hydrology, water quality and soil were investigated in the shoreline of total 35 reservoirs according to their usages of waterpower generation, agricultural water supply, residential and industrial water supply and flood control in Korea. The number of plant species, floral structure and characteristics of species traits in the shoreline of reservoirs were different according to their usage. From the results of stepwise regression analysis, the total number of vascular plant species was increased at the environment of the higher flood frequency at the median water level and the longer exposure duration of the shoreline. The results of principal coordinates analysis and cluster analysis showed that the shoreline flora was classified as the 3 types of 1) flood control and residential and industrial water supply, 2) agricultural water supply and 3) waterpower generation reservoirs. The water level fluctuation, flood frequency at the median water level, lake water quality index and exposure duration of the shoreline were selected as important environmental factors affected on the characteristics of shoreline flora. The species richness of total flora and hydrophytes, especially submerged macrophytes, were much higher in the reservoirs for the purpose of the waterpower generation in which mesotrophic water quality and stable water levels were maintained. Annual or biennial ruderals were established on the ephemeral drawdown zone of flood control, residential and industrial water supply reservoirs which have oligotrophic or mesotrophic water quality and wide range of water level fluctuation. The floating hydrophytes were differentially dominated in the littoral zones of the agricultural water supply reservoirs with a mesotrophic or eutrophic water quality and a medium water level fluctuation. In conclusion environmental factors related to water level fluctuation and water quality were different and then the floral characteristics of shoreline were distinguishable according to usage of Korean reservoirs.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.507-515
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• 2018

The results of the survey on water utilization status, the wasted water factor, the awareness, and the education and promotional activities of water saving in Daejeon City are as follows: The percentage of using tap valve with a closure was 66% when showering. 74% of water was used with closing the tap valve when washing faces with no water needed, it was still considered that there existed a wasting water. The most wasting reasons of water were found to be shower, bath, and laundry in order. In the awareness of practicing tap water saving, 9.1% of respondents acted actively, 53.4% of them were trying to practice it, and more than 63% had a positive awareness. In the contents of practicing saving water, locking water when soaping while showering, non-laundry of small quantity, and using cups when brushing teeth were top priorities. About 50% of the reasons for saving water was to practice purely saving water, when saving for economic help was excluded. The level of water saving awareness was not high when considering that the ratio of usage without water saving equipment and installation, and using method was relatively high when moving in. In order to make usage of water saving equipment more common, it was deemed necessary to provide information on the purchase of water saving equipment and to promote and educate the efficiency of saving of related products. More than about 90% of the respondents responded that water saving education or promotional activities had an effect of improving water saving awareness. The most effective method of education and promotional activities was found to be 40.4% by mass media activities, and 21.7% by promotions through mobile devices.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.399-407
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• 2012

Objectives : Purpose of this research is to determined the general knowledge on oral health and the usage of oral hygiene products in the orthodontic patients and try to provide an appropriate oral hygiene products for the patients. Methods : Orthodontic patients who visited a dental clinic in Daejeon were selected and data from 352 patients were collected. Questionnaire based on survey was conducted from 1st of March to 30th in 2011 and all the data was analysed by using SPSS statistical program (VER 15.0). Frequency analysis, $x^2$ test, T-test and the amount of diurnal variance analysis (one-way ANOVA) were also used. After that, scheffe's post-test method was conducted. Results : According to the general characteristics of oral health care knowledge score was $2.87{\pm}0.60$, the attitude score was $2.96{\pm}0.57$. toothbrush replacement cycle were less than 3 months (p=0.007, p=0.000) and frequency of brushing one day more than three times higher in patients with knowledge to help attitude. according to the sex, age, and duration of orthodontic treatment with oral hygiene devices of usage was higher in the calibration toothbrush usage, awareness was higher in the interdental toothbrushes. according to the type of orthodontic devices from the oral hygiene devices usage, removable group was the orthodontic toothbrush and electric toothbrush group were highest in the 'unknown', the fixed group was orthodontic toothbrush(67.3%) and electric toothbrushes(40.8%) was higher in the usage. Patients who used oral hygiene devices such as orthodontic tooth brush, interdental brush, electric toothbrush, water pik and fern solution showed wider knowledge on oral health care and oral hygiene devices compared to patients who answered as does not aware of oral hygiene devices and never used these products before. Conclusions : Orthodontic patient's oral health attitudes, knowledge, and oral hygiene devices usage are the general characteristics of the highest in the orthodontic toothbrush usage, awareness was higher in the interdental brush. Water pik and fern solution, rubber and gingival interdental stimulator turned massage does not use or low. Based on results from research, overall orthodontic patients who visited a dental clinic had low awareness and usage of oral hygiene devices. Therefore, it is required to educate general publics and the orthodontic patients and also promote the importance of usage of oral hygiene devices.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.06a
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• pp.7-8
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• 2003

• Journal of Korean Society of Disaster and Security
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• v.13 no.4
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• pp.65-74
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• 2020

Continuous and accurate instrument of river water usage is needed for sustainable river water management. Although the instrument methods applicable to each point of use of river water are different, more precise direct instrument methods are required at the point of major open channel. Users of river water should select appropriate direct instrument methods to measure usage, but there is a lack of standards and verification research. In this study, the H-Q rating curve method, ultrasonic method, and microwave method were applied directly to the test basin in the upper basin of Mangyeong river, and the accuracy of measurement data was evaluated by comparing absolute error between discharge data calculated by instrument method. When comparing the calculated discharge of point units, the ultrasonic method showed the best results of the actual measurement. Through continuous instrument, the sum of the daily and monthly units was compared, and the ultrasonic and microwave methods were shown to be highly accurate. Based on the results of this study, it is hoped that the appropriate direct measurement method can be selected according to the importance of the river water use facility, considering that the ultrasonic method and the microwave method are relatively costly compared to the water level-flow relationship method.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.1
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• pp.73-80
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• 2016

The aim of this study is to analyze the contribution of regional water resources through the gap between water used for rice production and water used for consumption. The blue water use for rice production and for consumption was quantified and the regional blue water flows were estimated using the virtual water concept from 1995 to 2010. About $1134.4Mm^3/yr$ of blue water flowed among the provinces and metropolises of Korea, and about 28.5 % of total blue water flows came from Jeonnam province. In addition, blue water usage for rice was classified into three categories: water for production, internal consumption, and overproduction in each region. In Jeonnam, $633.8Mm^3/yr$ of blue water totally used for rice production, and 50.9 % and 15.5 % were used for external and internal rice consumption, respectively. The other 33.6 % was used for over production of rice for food security. This study assumed the blue water flows depended on the gap between virtual water use for rice production and consumption. However, the analysis of regional blue water usage and flows might show the importance of other region's water resources, and make policy decision-makers aware of the integrated water management among the regions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.355-361
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• 2008

A water quality analysis of rainwater collected from catchment equipment ($2m{\times}1m$) was conducted to determine its suitability for domestic purposes, in this study. As the results of analysis, the pH of rainwater was $6.3{\pm}0.3$, and the turbidity of rainwater was over the 5 times than drinking water guidelines. For the usage of rainwater as the domestic and drinking water, the rainwater is need to treat. The analysis values of heavy metal as the Pb, Cd, Fe, Mn, ${Cr_6}^+$ and Cu was satisfied with drinking guidelines. Rainwater quality was improved in the rainfall duration. Overall results of analysis support the possibility of rainwater as the domestic and drinking water.