• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.509-516
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• 2014

This study describes a reasonable planning method for water meter replacement which can minimize the metering under-registration for an increasement of revenue water. The increment analysis of real water usage was used to establish a replacement plan. The meter replacement database collected from K City was used as the basis of this analysis. The database included 964 connections of domestic and non-domestic consumers that had their meter replaced by aging at 2011. The result showed that the corelation between unregistered water volume and water meter age was lower than commonly expected where the current criteria of replacement is only water meter age(8 years) excluding the meters older than 13 years. And in the analysis result of water usage for 8 years, the total amount and increment of water usage had a significant effect on unregistered water volume. However the relation was different tendency as a total volume and slope of increment. In case of total water volume was larger than 10,000, larger than 7,000 and increment of 0.0 ~ -0.3, larger than 6,000 and increment more than -0.3 were analysed to need a replacement because of metering under-registration.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.506-514
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• 2005

Unaccounted-for water subtracting water sold from produced water includes leakage, under-registration, unauthorized use, etc. To improve accounted-for water ratio, firstly, it should be attempted to accurately identify where unaccounted-for water is, and then it must to be reduced. Under-registration of meter is caused by allowable tolerance of meter, improper size of meter installed, gradient installation, etc. Under-registered water of meters has ever been the second large amount of unaccounted-for water next to leakage, but still is not estimated exactly. In this study, the estimated value as under-registered water was obtained by using the selected-area modeling program. As a result, the under-registered water ratio of 13mm meters was approximately 1.23%. Those of meters according to ages 1, 3, and, 5 years old were 1.46% 2.77% and, 2.26%, respectively but that of 7 years old meters showed over-registration of 1.59%.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.582-594
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• 2005

The under-registration of water meters of 20mm to 50mm in diameter, installed in Seoul city, was estimated by random sample method. The sample sites and sampled meters were selected for the measurements of flow rates and accuracy tests, respectively. The measurement of flow rates was conducted for 20mm to 50mm meters for about 20 days per site using flow meters and data loggers. The under-registration of 20mm, 25mm, 32mm, 40mm, and 50mm meters was observed as 3.96%, 1.10%, 2.47%, 4.04%, and 1.04%, respectively. The under-registration might be increased more or less as malfunction and failure of the sampled meters was not considered. In this study the under-registration of 20mm, 25mm, 32mm, 40mm, and 50mm meters was accurately estimated on the basis of the investigation data. The estimation of under-registration of water meters, one of the basic figures in water industry, contributed to accurate calculation of leakage, water supply and consumption, and strategic planning to reduce the unaccounted-for water.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.241-249
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• 1987

This study was carried out to investigate the effects of P, K and Ca on Perilla lipid content and composition. The results were summarized as follows; Seed yield of Perilla was more increased with P application than K and Ca. K application resulted in increased lipid content of Perilla seed, while P and Ca had no effect on lipid content. Triglyceride content in Perilla lipid was increased with application of P, particulary up to 92.1% with P+K+Ca application. Main fatty acids in Perilla lipid were palmitic, oleic, linoleic, and linolenic acid that is the most predominating fatty acid. P and Ca applicatin without K decreased the proportion of linolenic acid, and therefore degree of unsaturation when P and Ca were respectively applicated was 1.80 and 1.84, but when together with K they were respectively increased to 2.06 and 2.11. 4-Desmethyl sterols which is a predominating fraction in unsaponifiables of seed lipid were identified as campesterol, stigmasterol, and sitosterol. Of the 4-desmethylsterols, sitosterol showed the highest proportion at all pots with different kinds of fertilizers.