• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.35-43
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• 2006

Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.609-619
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• 2007

The objective of this paper is to evaluate the feasibility of conjunctive Operation between Multi-regional water supply networks from multiple source as a effective way to meet two conditions: to minimize the electric cost for providing water demanded and meet the water flow rate for satisfying customers. EPAnet Model is used to calculate a hydraulic water distribution condition based on an integrated operation of water supply systems located in short distance. The modeling was conducted on several simulation cases including the individual operation by existing inter-regional water supply networks within short distance, the conjunctive operation of more than two existing networks with valve fully closed and full open constraint. As a study distribution system, water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. It was found that a well-allocated water supply scheme based on a conjunctive operation promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. The result such as unit district costs, pareto optimum pump combination sets will be applied to the optimization for a conjunctive operation of existing inter-regional water supply networks within short distance.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.118-119
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• 2005

Recently, fire extinguishing systems based on water mists have been attracting public attentions in marine engineering. Performance of the fire extinguishing systems is influenced by the size and distribution of spayed water mists. Droplet analyzing method based on image processing technique for measuring droplet size and distribution has been developed. The morphological method based on partial curvature information of pre-processed images was adopted for recognition and separation of overlapped particles. Tested results show that the present method may be reliable for the analysis of the size and distribution of droplets produced by water mist spay flow.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.307-308
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• 2006

Recently, fire extinguishing systems based on water mists have been attracting public attentions in marine engineering. Performance of the fire extinguishing systems is influenced by the size and distribution of spayed water mists. Droplet analyzing method based on image processing technique for measuring droplet size and distribution has been developed. The morphological method based on partial curvature information of pre-processed images was adopted for recognition and separation of overlapped particles. Tested results show that the present method may be reliable for the analysis of the size and distribution of droplets produced by water mist spay flow.

• Journal of Korea Water Resources Association
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• v.31 no.3
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• pp.327-335
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• 1998

The distribution network is an essential part of all water supply systems. The cost of this portion of any sizable water supply system may amount to most of the entire cost of the project. This study tried to reduce the cost of the distribution system through optimization in system design. To determine pipe diameter considered in water distribution system design, a iterative procedure linked the flow analysis model and optimization model was used. Linear theory was introduced to analyze flowrate and revised-simplex method based on linear programming is used to optimize pipe diameter. This model was applied to wter distribution system with 22 and 35 pipes, and rapidly determine optimized commercial pipe diameters. Keywords : water distribution system, revised simplex method, optimum pipe diameters.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.602-609
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• 2011

In this paper, we standardized the water operation system picture, process control logic, realtime database and system configuration. All aspects, including monitoring & controlling processes, symbols such as pumps, valves and pipes were standardized. As a result we have developed a specialized Integrated water operation system, iWater. We have developed a variety of advanced application programs that are essential for water treatment systems, such as IWS (Integrated Warning system), MBO(modbus opc)/LSE(LS ethernet) driver, video monitoring, self diagnosis system, network monitoring, etc. IWS prevents water supply accidents by using a variety of alarms and warning messages. Drivers have the flexibility to communicate with other 3rd party systems. We expect that iWater will eliminate any concerns regarding water-related issues while also promoting the production and fair distribution of clean water.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.1
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• pp.67-73
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• 2007

Recently, fire extinguishing systems based on water mists have been attracting public attentions in marine engineering. Performance of fire extinguishing systems is very strongly influenced by the size and distribution of spayed water mists. Therefore, the present study has developed droplet analyzing method based on image processing. The morphological technique based on partial curvature information of pre-processed images with relaxation method was adopted for recognition and separation of overlapped particles. Tested results showed that the present method may be reliable for the analysis of the size and distribution of droplets in spray flow of fire extinguishing systems based water mists.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.175-196
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• 2002

The increase of meteorological uncertainty and unstable fluctuation of its behavior due to the global warming affect the temporal variation and spatial distribution of water resources and water use patterns in agriculture. There have been steady efforts to understand hydrological components and deal with such water related problems. This paper reviews firstly, the future effect of water resources due to climate changes, secondly, recent progress for precipitation, evapotranspiration, soil moisture, and thirdly, GIS/RS based integrated information systems conducted by both researchers and government ministries. There should be continuous studies and investments to cope with climate changes, and to accomplish sustainable development with the help of agricultural water resources. Some research topics were suggested to attempt with substantial contents considering our present capability and situation.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1153-1159
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• 2010

Identification of probability distribution for water quality constituents from specific land use is important to achieve successful implementation of TMDL program. In this 3-year study, distribution of discharge and BOD(Biological Oxygen Demand) concentration from paddy rice fields were monitored. Four probability distributions, normal, log-normal, Gamma and Weibull were fitted and the goodness-of-fit was assessed using probability plots and Kolmogorov-Smirnov test. $EMC_s$ of BOD in runoff from paddy field ranged 0.37 to $7.99\;mgL^{-1}$, and all four probability distributions were acceptable. But the normal distribution would be preferred for BOD from paddy fields considering nature of straight forward application.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1685-1692
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• 2015

This study examines the mackerel distribution systems in Norway which has a leading mackerel industry, and has the purpose of analyzing the effects of structural improvements for the development of Korea's mackerel industry. The landing and distribution status of Korea and Norway's mackerel industry was compared, and the effects of structural improvements was analyzed under the assumption that a number of factors would be improved after an analysis of competitiveness. Special features of the landing and distribution systems of mackerel in Norway are Reduction of transportation costs and transportation time through E-auctions, fish Pumps, freshness management using state-of-the-art equipment and technology such as sea water cooling systems, direct landing at processing factories and Automation through fully automated sorting & packaging systems. The distribution competitiveness of Korea and Norway's mackerel industry was compared through the qualitative review of landing time and the length of distribution channel, distribution costs due to differences in trading method, quality and hygiene management and merchandising. For Korea's mackerel industry to have international competitiveness, they must have efficiency throughout the phases of landing, processing and distribution systems as observed in case of Norway.