• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.329-332
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• 2007

Since enforcement of double entry book-keeping accounting system on 1 January 2007, local government should draw out financial statement for assets and liabilities possessed after due diligence. But, some social infrastructure including underground facilities are difficult to implement entire inspection actually. In this study, we proposed effective approach for assessing assets of local government's social infrastructure such as road, water and sewage, subsidiary facilities etc. using GIS built on local government by NGIS project. Through this, local government ensures correctness and effectiveness of asset inspection as a result of successive establishment of double entry book-keeping accounting system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.213-218
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• 2013

This paper presents are experimental investigation to figure out slamming impact pressure and flow characteristics of a wedge type structure in free fall. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method, the impact presure of free fall structure by a pressure acquisition system apply to Dewetron system. The angles between a model and the free surface are adapted $15^{\circ}$, $25^{\circ}$, $35^{\circ}$ and $45^{\circ}$ respectively. Velocity field of water exit has higher better than water entry. The impact pressure under the bottom of the model ha been appeared higher values at 15 degrees than 45 degrees, and also at P1.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.4
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• pp.371-377
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• 2012

This paper presents an experimental investigation to figure out slamming impact pressure and flow characteristics of a rectangular Marine structure($800{\times}250{\times}50mm^3$) in free fall. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method, the impact pressure of the free fall model by a pressure acquisition system(Dewatron). The angles between a model and the free surface are adapted $10^{\circ}$ and $20^{\circ}$ respectively. Velocity field of water exit has higher better than water entry. The highest point, P2 of impact pressure under the bottom of the model has been appeared about 6 % higher values at 20 degrees than 10 degrees.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.493-499
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• 2013

This paper presents are experimental investigation to figure out impact pressure and flow characteristics of a wedge type structure in free fall. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method, the impact pressure of free fall structure by a pressure acquisition system apply to Dewetron system. The angles between a model and the free surface are adapted $15^{\circ}$, $25^{\circ}$, $35^{\circ}$ and $45^{\circ}$ respectively. Velocity field of water exit has higher better than water entry. The impact pressure under the bottom of the model has been appeared higher values at $15^{\circ}$ than $45^{\circ}$, and also at P1.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.111-124
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• 2014

Decentralized water supply systems, treating the water in users'vicinity, cutting down the distribution system, utilizing the alternative water resources(rainwater harvesting, water reclamation and reuse and so on.) and saving energy and other resources, could be categorized into POU(Point-Of-Use), POE(Point-Of-Entry) and community small scale system. From the literature review, we could thought that decentralized water supply system and hybrid system(integrating centralized and decentralized water supply system within urban water management) might have strengthening comparative advantages to centralized system with respect to: (1) water security, (2) sustainability, (3) economical affordability. Even though it is difficult to derive and quantify direct benefit advantages from decentralized and hybrid system in comparison with centralized system, (1) operational cost reduction, (2) assurance for safe and stability water supply and (3) greenhouse gas reduction can be expected from successful establishment of the former.

• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.21-26
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• 2018

Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.28-33
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• 2006

Shallow failures of slopes in weathered soils are caused by infiltration due to prolonged rainfall. These failures are mainly triggered by the deepening of the wetting band accompanied by a decrease in suction induced by the water infiltration. In this paper, hysteresis on soil-water characteristic curve(SWCC) of granite and gneiss weathered soils are investigated using transient flow analysis respectively. Each case was subjected to artificial rainfall intensities and time duration depending on the laboratory-based drying and wetting processes. The results show that the unsaturated seepage on weathered slopes are very much affected by the initial suction of soils and unsaturated permeability of the soils. In addition, a granite weathered soil has a lower air-entry value, residual matric suction, and wetting front suction and less hysteresis loop than a gneiss weathered soil.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.6
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• pp.39-48
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• 2004

The purpose of this paper was to confirm the application of the equation of the soil-water characteristic curve on an unsaturated soil. To this ends, a series of suction test was conducted on the selected 4 kinds of soil which is located in Korea, using the modified pressure extractor apparatus. And it was carried out to analyze the experimental parameters which can describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that the matric suction was varied according to the grain size distribution, amount of fine grain particle and void ratio. Also it was found that the residual volumetric water content was decreased with the void ratio, but the index related air entry value, the soil parameter related water content and the parameter with residual water content were increased with the void ratio. And the application of equation of the soil-water characteristic curve was confirmed for the various conditions and the various state by the comparison between the volumetric water content measured by the experiment and the predicted values.

• Journal of the Korean Geotechnical Society
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• v.29 no.2
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• pp.57-64
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• 2013

In this paper, in order to solve high water content of water sludge and promote its recycle, sludge mixtures with various mixing ratios were produced. Sludge mixture consisted of water sludge and weathered granite soil. Their physical properties and unsaturated characteristics (soil-water characteristic curve, and unsaturated permeability function) were investigated by laboratory tests. Experimental test results indicated that at a given matric suction volumetric water content of sludge mixture increased as water sludge content increased. Air entry values of sludge mixture increased from 0.9 kPa to 2.4 kPa with an increase in water sludge content or fine content. In addition, unsaturated permeability function, which is an important factor for performing infiltration analysis, was predicted using saturated permeability and soil-water characteristic curve of sludge mixture.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.3
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• pp.376-381
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• 2006

This study is experimented to observe an influence of experimental conditions on production characteristics of slurry ice by putting ball into test section to disturb ice adhesion. And at this experiment it used ethylene glycol-water solution and the concentration is 20wt%. The experimental apparatus was constructed of ethylene glycol-water solution and slurry ice storage tank. brine tank, pumps for ethylene glycol-water solution and brine circulating, a mass flow-meter data logger for fluid temperature measuring and a vertical circular tube with two copper tubes as test section. The experiments were carried out under various conditions, with mean velocity of fluid at the entry ranging from 0.07 to 0.13m/s and ball diameter is 10mm, 15mm. Also ball filling rate is 33%, 50%.