• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1141-1148
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• 2013

End-uses of household water have been influenced by a housing type, life style and housing area which are considered as internal factors. Also, there are external factors such as water rate, weather and water supply facilities. Analysis of influential factors on water consumption in households would give an explanation on the cause of changing trends and would help predicting the water demand of end-use in household. In this paper, we used real data to predict toilet and laundry water-uses and utilized the linear regression model with autoregressive errors. The results showed that the monthly autoregressive error models explained about 71% for describing the water demand of end-use in toilet and laundry water-uses.

• Journal of the Korean Professional Engineers Association
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• v.35 no.4
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• pp.29-33
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• 2002

WATER, the best known and most abundant of all chemical compounds occurring in relatively pure form on the earth"s surface . And life, the material of which organisms are made by water and protoplasm. Especially, between human life and water must be joined by human"s protoplasm, proteins, nucleic acids cells energy exchange and anothers. Therefore. health of mankind is In according to drink enough clean water and to use good water environment.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.1
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• pp.75-84
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• 2011

This study was conducted to provide a basic information for the establishment of operation and treatment processes in sewer system of Nakdong river basin to minimize the overall pollutants loading to water body. Sewage flowrates were regularly measured and monitored at various sampling points of newly-built separated sewer system located in G City GA sites. To assess the inflow sewage flowrate, various calculating methods such as water-use evaluation, average-minimum daily flow quality evaluation, minimum daily flow evaluation, night water-use evaluation were used. Average I/Is were calculated except water-use evaluation. Average I/Is were found to be 6.5 $m^{3}/d$, 3.5 $m^{3}/d$, 7.7 $m^{3}/d$ at GA-1, GA-2, GA-3 points respectively. I/I ratios of three areas were found to be 4.8 %, 2.0 % and 2.7 % respectively and were obviously lower than those of the other separated sewer systems as shown in the previous studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.111-114
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• 2008

Explicit solutions of the wave dispersion equation are developed using the recursive relation in terms of the relative water depth. We use the solutions of Eckart (1951), Hunt (1979), and the deep-water and shallow-water solutions for initial values of the solution. All the recursive solutions converge to the exact one except that with the initial value of deep-water solution. The solution with the initial value by Hunt converged much faster than the others. The recursive solutions may be obtained quickly and simply by a hand calculator. For the transformation of linear water waves in whole water depth, the use of the recursive solutions will yield more accurate analytical solutions than use of previously developed explicit solutions.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.109-118
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• 1997

In this study, we examined the structural analysis of water demand fluctuation for water distribution control of water supply network. In order to analyze for the length of stationary time series, we calculate autocorrelation coefficient of each case equally divided data size. As a result, it was found that, with the data size of around three months, any case could be used as stationary time series. we analyze cross-correlation coefficient between the daily water consumption's data and primary influence factors. As a result, we have decided to use weather conditions and maximum temperature as natural primary factors and holidays as a social factor. Applying the multiple ARIMA model, we obtains an effective model to describe the daily water demand prediction. From the forecasting result, even though we forecast water distribution quantity of the following year, estimated values well express the flctuations of measurements. Thus, the suitability of the model for practical use can be confirmed. When this model is used for practical water distribution control, water distribution quantity for the following day should be found by inputting maximum temperature and weather conditions obtained from weather forecast, and water purification plants and service reservoirs should be operated based on this information while operation of pumps and valves should be set up. Consequently, we will be able to devise a rational water management system.

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05a
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• pp.67-75
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• 2001

Anticipated water scarcity in the first half of this century is one of the most concerned international issues. However, even though the issue has an international impact and world wide monitoring is critical, there are limited number of global estimates at present. In this study, annual water availability was derived from annual runoff estimated by land surface models using Total Runoff Integrating Pathways (TRIP) with 0.5 degree by 0.5 degree longitude/latitude resolution globally. Global distribution of water withdrawal for each sector in the same horizontal spatial resolution was estimated based on country-base statistics of municipal water use, industrial water use, and agricultural intake, using global geographical information system with global distributions of population and irrigated crop land area. The total population under water stress estimated for 1995 corresponded very well with former estimates, however, the number is highly depend on how to assume the ratio how much water from outside of the region can be used for water resources within the region. It suggests the importance of regional studies evaluating the possibility of water intake as well as the validity of the investment for water resources withdrawal facilities.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.784-794
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• 2020

In order to effectively evaluate the urban water security, the study investigates a novel system to assess factors that impact urban water security and builds an urban water poverty evaluation index system. Based on the contribution rates of Resource, Access, Capacity, Use, and Environment, the study adopts the Water Poverty Index (WPI) model to evaluate the water poverty levels of 14 cities in Gansu during 2011-2018 and uses the least variance method to evaluate water poverty space drive types. The case study results show that the water poverty space drive types of 14 cites fall into four categories. The first category is the dual factor dominant type driven by environment and resources, which includes Lanzhou, Qingyang, Jiuquan, and Jiayuguan. The second category is the three-factor dominant type driven by Access, Use, and Capability, which includes Longnan, Linxia, and Gannan. The third category is the four-factor dominant type driven by Resource, Access, Capability, and Environment, which includes Jinchang, Pingliang, Wuwei, Baiyin, and Zhangye. The fourth category is the five-factor dominant type, which includes Tianshui and Dingxi. The driven types impacting the urban water security factors reflected by the WPI and its model are clear and accurate. The divisions of the urban water security level supply a reliable theoretical and numerical basis for an urban water security early warning mechanism.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.277-279
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• 2002

In late of the 1980's, dramatic increase in water use caused over-exploitation of groundwater and deterioration of water quality in urban areas. To monitor quantity of groundwater resources and their qualities, local groundwater monitoring networks were established. Groundwater resources in urban areas are affected by various human activities including underground building construction (subway), pumping for water use, and pavements. Detailed analysis of the monitored groundwater data would provide some good implications for optimal and efficient management for groundwater resources in the urban area.

• The Korean Journal of Ecology
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• v.24 no.4
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• pp.253-258
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• 2001

Land use pattern in the Wangsuk river watershed was investigated on the bases of physiognomic vegetation maps made from the aerial photograph interpretation and field check. Landscape structure was analyzed using a GIS program supported by ArcView. Landscape structure depended on the geographical position of the river, such as the upper, middle and lower river. Watersheds of the upper and middle rivers were dominated by forests composed of secondary forest and plantation. But agricultural fields dominated that of the middle and lower river. Urban area and agricultural fields increased in from the upper toward the lower river watersheds. In addition to, a transformation of agricultural pattern into an institutional agriculture was characteristic in the middle and lower river basins. Water qualities of the Wangsuk river were usually better in the order of the upper, middle, and lower river, but they were fluctuated according to the site. Such fluctuation would due to self-purification of the river and land use pattern of the watershed as the non-point source. In this viewpoint, a strategy to manage the water quality in the level of watershed is urgently required.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.4
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• pp.3137-3146
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• 1973

This study was to investigate the effects of compaction, compressive strength and Atterberg limits in accordance with the temperatures changes. It was conducted on four soils-KJ, JJ, MH, SS-at temperatures of -1, 1, 3, 5, 7, 10, 15, 19, $22^{\circ}C$. These tests were obtained the maximum dry density and the optimum moisture content of four soils in accordance with temperature changes by using distilled water and $CaCl_2$ 10% solution, and were put to the compressive strength tests on remolded specimens of soils compacted at the optimum moisture content. The result of the study can be summarized as follows; The maximum dry density increased with an increase in temperature, and the use of $CaCl_2$ 10% solution had higher maximum dry density than distilled water. The optimum moisture content decreased with an increase in temperature, and the use of $CaCl_2$ 10% solution had lower optimum moisture content than distilled water. The maximum compressive strength was shown high peak from $7^{\circ}C\;to\;15^{\circ}C$, and the use of $CaCl_2$ 10% solution had higher maximum compressive strength than distilled water. The liquid limit and plasticity index decreased with an increased in temperature. It is estimated that the use of $CaCl_2$ 10% solution can lower the minimum compacted temperature from $2^{\circ}C\;to\;4^{\circ}C$ in low temperature.