• Solar Energy
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• v.20 no.3
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• pp.85-95
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• 2000

As the industry has been growing rapidly, the problem of environmental pollution has been on the rise seriously. In this paper, we used solar cells at the power supply unit of the equipment, which has been sold at present, for measuring the quality of water in order to complement the problem. Also, to get rid of the inconvenience that the examiners must go the job site, check and collect the polluted water we set the goal at designing the water pollution alarm system which measures the quality of water automatically using one-chip microprocessor and materializing the program.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.171-182
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• 2015

The economic effects of sewage and wastewater treatment service (SWTS) sector on other sectors have been rarely investigated in the literature. This paper attempts to apply an inter-industry analysis to looking into the economic effects of the SWTS sector. To this end, the most recently published 2012 input-output table is used here. In particular, the SWTS sector is specified as exogeneous to identify the economic effects of the SWTS sector on other sectors. Production-inducing effect, value-added creation effect, and employment-inducing effect are quantified based on demand-driven model. Supply shortage effect and price pervasive effect are also analyzed employing supply-driven model and Leontief price model, respectively. The results show that production-inducing effect and value-added creation effect of a unit of investment or production in SWTS sector are estimated to be 1.7076 and 0.7392, respectively. The employment-inducing effect of one billion of investment or production in the SWTS sector is computed to be 11.0498 persons. The shortage effect of the SWTS sector amounts to 0.8417 won. The overall price effect of the 10% increase in the price of SWTS sector is calculated to be 0.0115%. This quantitative information can be utilized in predicting the economic effects of the SWTS sector-related activities or policy-making.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_2
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• pp.307-313
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• 2023

This study conducts the flow analysis on the basis of the impeller RPM of water metering valve. The software used for the flow analysis is STAR-CCM+. In terms of the structure of the metering valve, it has an impeller installed inside, and a metering chamber has inlet and outlet holes. The flow analysis on the water metering valve drew the following conclusions: Regarding the flow field in the valve, the impeller had the highest velocity distribution, and complex flow field was generated in the metering chamber. In particular, since the path between the inlet and outlet holes in the metering chamber and the valve body was narrow, there was a section that had flow field interference. The flow rate and flow coefficient distribution according to the impeller RPM were on the linear increase. Given that, it showed the feature of the valve used for water metering on the basis of the impeller RPM.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.447-457
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• 2017

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.23-31
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• 2015

Aquifer storage transfer and recovery (ASTR) is a type of managed aquifer recharge which entails injecting water into a storage well and recovering it from a different well. It has effects of natural purification when injected water passes through aquifer medium, and can be a good way of supplying water especially in a region with poor surface water quality. This study is about an on-going effort to introduce ASTR as a solution to source water problems in coastal areas. A pilot study is being conducted in the delta of the Nakdong River. A proactive management system is incorporated to ensure the water qulity in the process of drinking water process. The system is based on the Hazard Analysis and Critical Control Point (HACCP) which is a tool originated from the food industry in order to assess hazards and establish control systems for the safety of food product. In this paper, we analyze hazardous events which can occur in the entire water supply system using ASTR as a first step to the incorporation of HACCP to drinking water production process.

• Electronics and Telecommunications Trends
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• v.36 no.5
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• pp.62-73
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• 2021

A stable protein source is required to support the rapidly increasing global population, and fishery products are a particularly important part of the required protein supply. However, due to continued overfishing, fishery resources are depleted, and the number of fish caught by fishing boats has stagnated. Consequently, the aquaculture industry is becoming increasingly important. Internationally, smart aquaculture technology that minimizes labor and environmental pollution has been established through technological developments supported by large investments in automation and water treatment technology over the last several decades. In the case of Korea, the aquaculture industry has not yet emerged as a labor-intensive primary industry. However, in recent years various attempts have been made to apply ICT technology to aquaculture to overcome these problems. In this study, domestic and foreign technologies and patent trends for smart aquaculture are analyzed. In addition, the current status of the smart aquaculture cluster business that the Ministry of Oceans and Fisheries has been promoting since 2019 to utilize ICT technology in aquaculture is introduced.

• 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.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.118-129
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• 2009

To develop a sustainable management model for oyster farming in Pukman Bay, Korea, we estimated the carrying capacity for oyster farming using food availability data. Optimal culture densities were calculated to be 124-133 individuals per unit flux area ($m^2$) and 310-330 individuals per string. The present annual production is approximately 1,038 tons/year, which is 87% of the estimated maximum yield of 1,193 tons/year. Therefore, considering annual fluctuations and a critical buffer to reduce ecological impacts, the current level is within optimal conditions. During periods of increased water temperature, energy demand was largely met by high primary production. The food supply significantly decreased as the harvest season approached, and 10 out of 21 oyster farms had a deficient food supply for at least 1 month. Therefore, these farms (39% of the farms within the bay) exceeded optimal densities.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.29-42
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• 2016

This study analyzes the economic efficiency of utilizing hot waste water at a thermoelectric power plant, which is part of recent projects supported by the Korean government to foster new energy industry. The author proposes an institution that provides economic incentives to promote the project. Based on a method of calculating Levelized cost of energy (LCOE), this study finds that the LCOE of using hot waste water at power plants is higher than that of oil boiler, biomass and a power plant's auxiliary steam but similar to that of the geothermal system. Also, according to sensitivity analysis on the LCOE of each element in the system of using hot waste water, a distance of heat supply is most sensitive. Therefore, this study shows that when the government devises an incentive-based institution to expand the project of utilizing hot waste water, it is necessary to establish Renewable Energy Certificate (REC) weights that are differentiated by a distance of heat supply.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.190-200
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• 2018

This study estimated the marginal production value based on the production function approach to confirm the economic value of industrial water supply projects. For this, we analyzed 4 data sets classified by 11 industry types according to Cobb-Douglas Function, Translog Function, and Translog function with sector dummy variables. As a result, the average industrial marginal product value of the entire industry was 3,217~5,357 won/ton, 2,994~4,569 won/ton and 3,620~5,342 won/ton, respectively. The results by industry type were the largest in furniture and other manufacturing industries and showed the lowest marginal production value in the textile and leather industries. Overall, the results from the Cobb-Douglas function were highly evaluated. And the volatility according to data sets was also analyzed in the Cobb-Douglas function. There have been few studies on the economic value of industrial water compared to domestic water. It is considered that multidisciplinary consensus will be needed through active research in the future.