• The Journal of Engineering Geology
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• v.4 no.3
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• pp.297-309
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• 1994

For a total of 210 city and Kun areas in Korea, a model was developed to predict the amount of groundwater use at each area. At first, the total areas were classified into 3 groups by the characteristics of groundwater use: residential(87), industrial(27) and agricultural (96) areas. Among them, type areas, represented by the dominant groundwater usage for typical purposes, were selected: residential(22), industrial(8) and agricultural(32) areas. Data for the various factors possibly related to the groundwater use were statistically analyzed. The factors include, 1) agricultural area, 2) industrial area, 3) adininistrative unit area(city or Kun), 4) population, 5) groundwater capadty for community water supply, 6) average water supply for a person per day, 7) agricultural water-use, 8) industrial water-use, 9) residential wateruse, 10) rates of community water supply. The data were correlated to the total amount of groundwater use, and the correlations tested at the 95% and 99% significance levels. Influential, significantly related, factors were identified from the tests. Using the multiple regression method with the influential factors, predictive equations were drawn to calculate the amount of groundwater use for residential-industrial and agricultural areas, respectively. The equations were calibrated to minimize the RMS(root mean square) of the differences between predicted and observed groundwater use. After the validation with future data, the model can be utilized in the regional development plans to predict the maximum groundwater demand at each area.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2182-2189
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• 2004

In the recent years, environmentally conscious design and manufacturing technologies have attracted considerable attention. The coolants, lubricants, solvents, metallic chips and discarded tools from manufacturing operations will harm our environment and the earth's ecosystem. In the present work, the Tukey method of multiple comparisons is used to select the minimum level of coolant required in a turning process. The amount of coolant is varied in 270 designed experiments and the parameters cutting temperature, surface roughness, and specific cutting energy are carefully evaluated. The effects of coolant mix ratio as well as the amount of coolant on the turning process are studied in the present work. The cutting temperature and surface roughness for different quantity of coolant are investigated by analysis of variance (ANOVA) - test and a multiple comparison method. ANOVA-test results signify that the average tool temperature and surface roughness depend on the amount of coolant. Based on Tukey's Honestly Significant Difference (HSD) method, one of the multiple comparison methods, the minimum level of coolant is 1.0 L/min with 2% mix ratio in the aspect of controlling tool temperature. F-test concludes that the amount of coolant used does not have any significant effect on specific cutting energy. Finally, Tukey method ascertains that 0.5 L/min with 6% mix ratio is the minimum level of coolant required in turning process without any serious degradation of the surface finish. Considering all aspects of cutting, the minimum coolant required is 1.0 L/min with 6% mix ratio. It is merely half the coolant currently used i.e. 2.0 L/min with 10% mix ratio. Minimal use of coolant not only economically desirable for reducing manufacturing cost but also it imparts fewer hazards to human health. Also, sparing use of coolant will eventually transform the turning process into a more environment-conscious manufacturing process.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.123-128
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• 2018

Recently, the use of contrast agents has been increasing as a broader range of tests and dynamic tests have become common due to the development of equipment and imaging techniques such as Multi-Detector CT. However, the side effects of using contrast agents have been reduced by the development of non-ionic contrast agents, but they are still occurring often. The purpose of this study was to propose a method to minimize the side effect of contrast agent by using the amount of contrast agent injected to the brain angiography test to suppress excessive use of contrast agent and analyze the amount of contrast agent. Patients who were prescribed Brain Angiography due to cerebrovascular disease, According to the results of the comparison of the results obtained by dividing into 4 groups of 10ml each according to the amount of contrast medium injected with contrast agent according to the BMI of the patient, BA and SNR were not different between groups, and even if the amount of contrast injection was reduced, there was no problem in the evaluation of CT angiography through 3D reconstruction. This result shows that even if the contrast medium is injected into the blood vessels of the patient first and then the contrast medium is used as the physiological saline solution, the contrast medium is reduced by 40% it can be expected to minimize.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.33-36
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• 2002

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.599-608
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• 2013

Jeju island, which is located along the moving path of typhoon, suffers from flooding and overflow by torrential rain. So abrupt runoff occurring, damages of downstream farm field and shore culturing farms are increasing. In this study, Oaedo stream, one of the mountainous streams on Jeju island, was selected as the basin of study subject and was classified into 3 sub-basins, and after the characteristics of subject basin, the soil erosion amount and the sediment delivery of the stream by land usage distribution were estimated with the use of SATEEC ArcView GIS, the sediment yield amount of 2000 and 2005 was analyzed comparatively. As a result of estimating the sediment yield amount of 2000, the three sub-basins were respectively 12,572.7, 14,080 and 157,761 tons/year. and sediment yield amounts were estimated as 35,172.9, 5,266 and 258,535 tons/year respectively in 2005. The soil erosion and sediment yield amount of 2005 using single storm rainfall were estimated high compared with 2000, but for sub-basin 2, the values rather decreased due to changes in land use, and the land coverage of 2005, since there are many classifications of land usage compared with 2000, enabling to reflect more accurate land usage condition, could deduce appropriate results. It is anticipated that such study results can be utilized as basic data to propose a direction to predict the amount of sediment yield that causes secondary flooding damage and deteriorates water quality within detention pond and grit chamber, and take action against damages in the downstream farm field and shore culturing farms.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.129-136
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• 2017

Climate change is the biggest environmental issue of our times. A variety of activities to reduce greenhouse gas emissions have been in progress to observe the Kyoto Protocol. Especially, the Energy Target Scheme is created to reduce greenhouse emission with the supervision of Korean government. This includes Green-house Gas Information Systems to promote activities in the private sector to reduce green-house gas emissions, to cut a cost of energy use, and to reduce GHG emissions. Also, the system has calculated the amount of greenhouse gases. Without any additional investment, 2.75% savings are increased over the previous year. In service sector, a cooperation of customers and employees is necessary. A reduction of GHG emissions requires a proper service organization, considering an amount of investment and payback period. Without any additional investment or replacement, employees can save energy easily turning off ventilation systems an hour before employees' departure, installing timers to turn off water purifiers and vending machines after some period of no use. The Green-house Gas Information System is similar to that of Environmental Management System. However, the Excel is the best program to calculate an amount of green-house gas emissions, and to assess for a reduced amount of GHG emissions. A goal of this research is to propose a practical method in the private sector to calculate an amount of green-house gases. The Green-house gas Information System based on Excel spreadsheet gives standards for good evaluation. The greenhouse gas information system establishes and executes the policies and objectives related to greenhouse gas emissions Similar to ISO 14001 environment management system structures, the advantages of using simplified Excel Sheet for calculating GHG emissions and reducing GHG emissions are easy to access.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.639-649
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• 2013

Over 96.2% of the agricultural water in Jeju Island is obtained from groundwater and there are quite distinct characteristics of agricultural water demand/supply spatially because of regional and seasonal differences in cropping system and rainfall amount. Land use for cultivating crops is expected to decrease 7.4% (4,215 ha) in 2020 compared to 2010, while market garden including various vegetable crop types having high water demand is increasing over the Island, especially western area having lower rainfall amount compared to southern area. On the other hand, land use for fruit including citrus and mandarin having low water demand is widely distributed over southern and northern part having higher rainfall amount. The agricultural water demand of $1,214{\times}10^3\;m^3/day$ in 2020 is estimated about 1.39 times compared to groundwater supply capacity of $874{\times}10^3\;m^3/day$ in 2010 with 42.4% of eastern, 103.1% of western, 61.9% of southern, and 77.0% of northern region. Moreover, net secured amount of agricultural groundwater would be expected to be much smaller due to regional disparity of water demand/supply, the lack of linkage system between the agricultural water supply facilities, and high percentage of private wells. Therefore, it is necessary to ensure the total net secured amount of agricultural groundwater to overcome the expected regional discrepancy of water demand and supply by establishing policy alternative of regional water supply plan over the Island, including linkage system between wells, water tank enlargement, private wells maintenance and public wells development, and continuous enlargement of rainwater utilization facilities.

• The Korean Journal of Food And Nutrition
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• v.4 no.2
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• pp.115-124
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• 1991

In order to improve the quality of Takju, the effect of combined use of Aspergillus oryzae and Aspergillus kawachii in brewing was investigated. The quality of Takju which was brewed by the combined use of Aspergillus oryzae CF7-koji and Aspergillus kawachii CF1-koji in equal amount was better as cmapared with that brewed by existing method using Aspergillus kawachii-koji only as koji. But the good result did not obtained when the koji was made by mixed culture of Aspergillus oryzae CF7 and Aspergillus kawachii CF1.

• Proceedings of the KSR Conference
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• 2006.05a
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• pp.34-45
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• 2006

Making practical use of urban MAGLEV system which is tried by government includes technique development and railway construction. Because huge amount of money will be spent on this project, feasibility study is being carried out in order to check the feasibility and to devise the master plan in prior to making practical use of urban MAGLEV system. The key issues of feasibility study are possibility of technique development, economical feasibility, location of a model railway and the improvement of related laws and regulations. This paper shows the approach to solve these key issues.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.1
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• pp.17-37
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• 1987

The purpose of this study is to establish more rational and practical planning theory for amusement park. It analyze and consider the fluctuation of people who come and use the Tong-Ch'on amusement park. The results drawn from this reserch work are as follows; 1. The main visitors of the Tong-Ch'on amusement park are students in their twenties and thirties, and people whose incomes are below 300,000 Won a month. The purpose of visit is for a rest rather than for amusement and user prefer summer, while the user is so rare in wintertime. Those phenomena observed are somewhat different from the real purpose of a amusement park which is on purpose to make profits by offering entertainments to the users. So planner should pay attention to the three points. They are varieties, seasonable diversification and fantastic character of facilties, in the amusement park. 2. The access time of the Tong-Ch'on amusement park was 41 minutes, the use frequency was 4 times a year and resident time was 164 minutes. The relationship of the three factors are as follows; log Y(F) =1.7832-0.0277(A.T) R$^2$=0.75 Y(R. F)=31.8885+3.3217(A.T) R$^2$=0.53 Y(R. T)=224.8959-87.8309 1og(F) R$^2$=0.38 F;Use frequency(time/year) A.T;Access Time(minute) R.T;Resident Time(minute) 3. In the choice of space, there were much differences according to tole user's age, job, degree of education, companion type and purpose of use. 4. There are considerable correlation between use fluctuation and some factors. The factors are season(summer, winter) as a time, temperature, cloud amount, duration of sunshine, weather(rainy-day) as a climate and a day of the week(weekday, holiday) as a social system. The important variables are temperature, cloud amount, duration of sunshine and a day of the week(weekday, holiday) to estimate the user of amusementpark. 5. 1 can reduce the following two types of regression models. 1) log$\sub$e/ Y1 = 6.9114 + 0.l135 TEM + 0.00002 SUN -0.4068W1 + 0.4316 W3 (R$^2$= 0.94) 2) log$\sub$e/ Y2 = 7.2069 + 0.l177 TEM - 0.0990 CLO + 0.4880 W3 (R$^2$=0.95) Y; Number of User TEM; Temperature CLO; Amount of cloud SUN; Duration of Sunshine W1; Weekday W3; Holiday Those model is in order to estimate the user for management of Tong-Ch'on amusement park and use on the computation of facility sloe for reconstruction. Besides the amusement park, city park and outdoor recreation area could estimate of user through this method. But, I am not sure about the regression models because I did not apply the regression models to the other amusement park, city Park or outdoor recreation area. Therefore, I think that this problem needs to be studied on in the future.