• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.891-906
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• 2014

This study suggests the hedging rule of MIP (Mixed Integer Programing) in counting the risk evaluation criteria of the objective function and constraints in order to provide the optimum operating rule in reservoir system as constraining water shortage as much as possible which may happen in the downstream control point of water supply in the aspect of water system management. The proposed model is applied to the Han-river reservoir system for two testing periods (Case I: Jan. 1993~Dec. 1997, Case II: Jan. 1999~Dec. 2003). The model based on the hedging rule with trigger volume, estimated in this study shows that in Case I, the monthly minimum discharge was $310.6{\times}10^6m^3$ in the single operation, $56.3{\times}10^6m^3$ in the joint operation, and $317.5{\times}10^6m^3$ in the hedging rule and also, in Case II, the monthly minimum discharge was found to be $204.2{\times}10^6m^3$ in the single operation, $111.2{\times}10^6m^3$ in the joint operation, and $243.7{\times}10^6m^3$ in the hedging rule. In conclusion, the hedging rule, proposed in this study can decrease vulnerability while guarantees reliability and resiliency.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.205-212
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• 2001

Joongpyong reservoir and Guiseok pumping station were selected as the hydrologic monitoring sites for the water level gauging and amount of irrigation water use, and water samples were taken and analysed periodically. Rating curves were derived from the relations water level and discharge data, and water supply through culvert of the Joongpyong reservoir was $593,200m^3$ and irrigation water $2,913,000m^3$ from the Guiseok pumping station. Changes of stream water qualities such as water temperature, pH, EC, total nitrogen, total phosphorus were examined, pH was 6.98.1 lower than the criteria of agricultural water 6.0~8.5, total nitrogen $0.9{\sim}4.5mg\;L^{-1}$, total phosphorus $0.008{\sim}0.036mg\;L^{-1}$. The results from this study could be offered as a basic data for the irrigation plan and water quality management.

• Korean Journal of Plant Resources
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• v.16 no.2
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• pp.99-108
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• 2003

This study was carried out to make a standard criteria for protection and maintenance of the big and old trees in Ansung city, Kyonggi Prvince. There have been found 6 vegetative species cultivated in this area, which are Zelkova serrata, Gingko biloba, Kalopanax pictus, Pyrus ussuriensis var. macrostipes, Pyrus ussuriensis var. acidula, Pinus densiflora, etc. The Zelkova serrata tree is the major species among them and about 73.5％ in the population of the big and old trees in this area. The DBH (diameter at brest height) of them is 1.5-1.9m in 29.4% of whole population and the tree height is 10-l4m in 47.1%. The estimate age of 7 trees is more than 500 years old and they were 20.6％ of the whole population. Interesting point is that about 64.7％ of these trees in this area have own succeed story in terms of folk religion, object of worship, taboo, legend or secret. This study has also revealed that many fowls, small animals and epiphyte inhabited with the big and old trees have been found. However, 97.1％ of them are in danger from the plant disease and noxious insects or cutting damage of branches, but no management has been taken. More over, 85.3％ of the whole investigated big and old trees have been in the poor condition for percolation or aeration because the area around them has been payed with asphalt or concrete.

• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.54-60
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• 2000

Purpose : The purpose of this study was to evaluate the gutter pathologies and the clinical results of arthroscopic treatment for ankle gutter syndrome. Materials and Methods : Seventy six patients(77 ankles) who had lesions in the ankle gutter were treated by arthroscopy. The gutter pathology could be divided into 3 categories; hypertrophic scar tissue, loose bodies and bone spurs. Fifty two patients were evaluated subjectively and functionally with authors' criteria. The follow-up period averaged 44 months(range, 2.9 year-8.5 year). Results : The incidence of the gutter lesion was $21\%$(77 ankles) among 366 ankles undergoing arthroscopy. The most common pathology was hypertrophic scar tissue. In 31 ankles$(40\%)$, the lesions were found only in gutter, and 46 ankles$(60\%)$ were associated with pathologies in other areas. All of parameters for subjective and functional evaluation were improved with statistical significance(p<0.001). Seventeen patients$(33\%)$ could returned to competitive or contact sports activity with same level of premorbid period. Conclusion : Ankle gutter is an important site of pathologies which cause chronic ankle pain, and should be explored in ankle arthroscopy. The ankle arthroscopy is a very effective treatment method fur the removal of pathologies in ankle gutter syndrome.

• Korean Journal of Childcare and Education
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• v.10 no.5
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• pp.5-23
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• 2014

The purpose of this study was to identify factors affecting extra expenses incurred by extracurricular activities, prompted by the problem that the financial burden on households for their children's education and child-care is not showing enough signs of being mitigated, despite increased child-care subsidies from the government. Data for this study was obtained from the 4th Panel Study on Korean Children of Korea Institute of Child Care and Education. The analysis of the study shows that 68.5% of the surveyed children were participating in extracurricular activities and the average number of extracurricular activities they took part in was 2.9. The average extracurricular expenditure was 50.000 won. However, based on the findings of the survey, it was statistically significant to find that the number of extracurricular activities the children participated in and the expenditure the households spent on them varied by area. Variables were inserted in a gradual manner in identifying factors influencing households' expenditure on children's extracurricular activities. The results showed that amongst the variables used, the education level of the mother, the employment status of the mother, the type of the child-care support institution, and the household's place of residence featured prominently, with the place-of-residence factor accounting for most of the reason why a household spent the amount it did. The outcome of the study bears four policy implications: First, there is a need for a specific evaluation of the contents and costs of extracurricular activities and supervision and management of such activities. Second, it is necessary for the central government to provide a specific criteria of necessary expense. Third, throughout the child support agency, the courses and costs of special activities should be monitored regularly. Fourth, there should be extracurricular activity support for underprivileged children.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.1-10
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• 2006

The objective of this study was to develop a GIS application model for analyzing site-specific suitability and investment efficiency of major plantation tree species. The model was designed to choose the best plantation species in terms of both potential stand growth and investment efficiency. Site index and IRR were used as the criteria for the potential of stand growth and investment efficiency, respectively. In the model, the conditions of forest stand management and site index are estimated as the function of site-environmental factors extracted by a series of spatial analyses of digital maps of FGIS. Based on site index values of tree species, the model screens out all the high potential tree species, in terms of stand growth, as the candidates for species selection and, then, calculates IRR for managing plantation forest stands for all the candidate tree species. The tree species of the highest IRR would be chosen as the one possessing the highest potential in terms of stand growth and profit. The model was applied to a case study for analyzing the site-specific suitability of 6 tree species in Taehwa University Forest of Seoul National University and the results are given in this paper.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.53-63
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• 2016

In this paper, we proposed the improvements for performance test and surveying equipment regulations, standards, methods and procedures, depending on the need of improving the legal system for surveying equipment in a diverse and sophisticated surveying industry. This research was performed first investigating the existing legal systems(Act on the establishment and management of spatial data, Framework act on national standards, ISO 17123, JIS B 7912) with respect to the surveying equipment performance testing and the research for IOS and KOLAS suggested the improvements on the application for the surveying equipment performance testing standard. More exactly, first, two years were presented for the surveying equipment performance testing cycle considering the precise accuracy of the instrument stability, purpose and frequency of use, etc. Second, the abolition of the measurement distance by grade and the upward or cross-grade adjustment of the single prism standards about the light wave rangefinder and total station were suggested for the improvement on survey equipment performance criteria. Third, since the main function of total station is focused on a three-dimensional coordinate measurement due to the improvement of surveying equipment performance testing, it was proposed to use the precision(repeatability) of the coordinate measuring method as an evaluation method.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.215-226
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• 2020

Chatbot is emerging as an important interface window for business. This change is due to the continued development of chatbot-related research from NLP to NLU and NLG. However, the reality is that the methodological study of drawing domain knowledge and developing it into a user-friendly interactive interface is weak in the process of developing chatbot. In this paper, in order to present the process criteria of chatbot development, we applied it to the actual project based on the methodology presented in the previous paper and improved the development methodology. In conclusion, the productivity of the test phase, which is the most important step, was improved by 33.3%, and the number of iterations was reduced to 37.5%. Based on these results, the "3 Phase and 17 Tasks Development Methodology" was presented, which is expected to dramatically improve the trial and error of the chatbot development.

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.233-239
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• 2017

Objectives: The pollution status of heavy metals within the soil was investigated with an aim to establishing a sustainable soil environment within parks and amusement facilities installed in urban areas of Gyeonggi-do Province. Methods: As sampling sites, 14 locations were selected from a city with a number of factories near a residential area, a residential area, and a children's park in a city with mixed green areas. Seven kinds of heavy metals, including Cd, Pb, and Hg, and the pH of soil were analyzed three times by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectrometer (AAS). Results: In this study, the pH of the samples from the residential park and industrial park showed 5.7-6.5 and 5.9-7.0, respectively. The overall mean concentration (mg/kg) of heavy metals was Zn (132.8), Ni (73.0), Cu (47.4), Pb (35.9), As (4.84), Cd (0.39), and Hg (0.07), indicating that these concentrations of heavy metals were lower than those for the area 1 standard of soil pollution concern criteria. In addition, the sampling sites in the residential area and the industrial area also showed the same tendency for concentration distribution. Conclusions: We found that the soil pollution class (SPC) of some spots were over 200, which are third and fourth classes. In order to manage a sustainable soil environment in a city park, it is suggested that local governments, the management bodies for these parks, need to manage, supervise, and investigate soil pollution and quickly replace contaminated soil.

• Journal of Environmental Science International
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• v.16 no.1
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• pp.81-94
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• 2007

The purpose of this work is to investigate the water quality change characteristics of treated water in water distribution systems of Water Treatment Plants (WTPs) of Jeju City. For this, the raw water, treated water and tap water that did not pass (named as not pass-tap water) and passed through the water storage tank (named as pass-tap water) were sampled and analyzed monthly from September 2001 to August 2002, for four (W, S, B and O) WTPs except for D WTP (where treated water is not supplied continuously) among WTPs of Jeju City. The concentrations of $NO_3^-$ and $Cl^-$ of treated water in distribution systems changed little, but changed seasonally, which is considered to be based on the seasonal variation of the quality of raw water. The pH of treated water changed little in distribution systems for S WTP, but for the other WTPs, the pH of not pass-tap water was similar to that of treated water and the pH of pass-tap water was higher than that of treated water. The turbidity of treated water in distribution systems changed little except for W2 of W WTP and S4 and S5 of S WTP, where it was higher than that of each treated water. The residual chlorine concentrations between treated water and not pass-tap water changed little, but those between treated water and pass-tap water changed greatly, based on the its long residence time in water storage tank and so its reaction with organic matter, etc or its evaporation. The concentrations of TTHMs (total trihalomethanes) and $CHCl_3$ that induce cancers in water distribution systems of these WTPs, were much lower than their water quality criteria and those in other cities. The concentrations of TTHMs of treated water and not pass-tap water were similar, but concentrations of pass-tap water were 1.5 to 2.0 times higher than those of treated water and not pass-tap water, due to the reaction of residual chlorine and organic matter, etc, with the result of long residence time in water storage tank.