• Proceedings of the Korea Concrete Institute Conference
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.606-609
• /
• 2006

In this study, it was selected that in order to make an investigation into the status of the unit water content control of the ready-mixed concrete plants in the country, Capacitance Measurement Method out of various methods which are able to gauge the amount of unit water content in fresh concrete. Then, it were estimated that the quantity of unit water in fresh concrete and the technical standard of every mixture design of the six ready-mixed concrete plants chosen at random in the country. Finally, based on this study, it was proposed as fundamental data to utilize measurement techniques of the quantity of unit water for the quality control of the ready-mixed concrete in construction field.

• Journal of Korea Water Resources Association
• /
• 제53권11호
• /
• pp.1015-1024
• /
• 2020

Recently, water pollution accidents have continued to occur in pipelines such as red water Incheon and Seoul. In order to recognize this water quality problem, it is necessary to install a water quality sensor in an appropriate location and measure it in advance to detect or block the water supply to the water faucet of the shelter. However, there are limitations, such as maintenance costs, to installing multiple water meters in all pipelines. Therefore, this study proposed a methodology for determining and prioritizing the installation location of flow-based water quality sensor for the recognition of water quality problems in pipelines. We applied the proposed procedure to the pipe break scenario. The results of the determination of the location of the water quality sensor were presented by applying it to the pipe network that actually operates the emergency pipe in Korea. The result of the decision showed that in the event of abnormal situation caused by the destruction of individual pipes, the flow rate of the pipes around the aqueduct and the tank may change rapidly, resulting in water quality accidents caused by turbidity. In the future, it is expected that the water quality monitoring point selection method, such as establishing an external pipe operation plan for pipe cleaning, will utilize the procedure for determining the location of the water quality sensor according to the velocity.

• Journal of the East Asian Society of Dietary Life
• /
• 제9권4호
• /
• pp.452-460
• /
• 1999

This study was conducted in order to investigate the quality characteristics of Salku Pyun which was made by using mungbean, potato, sweet potato and corn starches. The pH of salku juice was 3.45 to 3.50 and the brix of that was 7.0%. The water content and water activity of salku pyun with potato starch was highest. The result of sensory evaluation showed that appearance, flavor, overall quality were highest in the Salku Pyun made with potato starch while texture, taste were highest in the Salku Pyun made with mungbean starch. Mechanical properties of salku pyun with mungbean starch was significantly higher in adhesiveness, hardness, chewiness. Texture of sensory evaluation were positively correlated with springiness, hardness, and chewiness of mechanical measurement. The factors which affect the overall quality on sensory evaluation were texture quality, taste quality, hardness, color and springiness.

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• 한국환경생태학회 2004년도 정기총회 및 학술논문 발표회
• /
• pp.95-96
• /
• 2004

• Journal of Korean Society on Water Environment
• /
• 제23권6호
• /
• pp.889-896
• /
• 2007

From the direct outflow of Chungju Dam to the junction of water body and watershed in Paldang lake is the scope of this research. This study performed to investigate the main cause of water quality deterioration and the influenced region in the middle field range of the Namhan river Basin with the onsite measurement of water quality and flow rate simultaneously during spring dry season. The purpose of this study is to find out the time-spatial variation characteristics of water quality and flow rate. Following the flow direction $BOD_5$ and $COD_{Mn}$ concentration increased to the highest value of 3.7 mg/L, 5.9 mg/L at Wolgesa respectively. Chl.a concentration increased to $50mg/m^3$ or so at Kangsang, after that it decreased to $37mg/m^3$ at the junction of Paldang lake. Organic matter concentration variation trend showed similar than that of Chl.a. Also $BOD_5$ concentration tendency was similar to Chl.a in every measuring sites except Paldang lake mixing zone. The major factors of water quality deterioration in Namhan river and Paldang lake during dry season were algal bloom and followed internal production. High phosphorus load from Dalcheon and Seom river caused dry season algal bloom and internal production in transitional zone which was stagnant area in downstream of Namhan river.

• Proceedings of the Korea Concrete Institute Conference
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.705-710
• /
• 2002

Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 한국건축시공학회 2021년도 가을 학술논문 발표대회
• /
• pp.8-9
• /
• 2021

The unit-water content of concrete is one of the important factors in determining the quality of concrete and is directly related to the durability of the construction structure, and the current method of measuring the unit-water content of concrete is applied by the Air Meta Act and the Electrostatic Capacity Act. However, there are complex and time-consuming problems with measurement methods. Therefore, high frequency moisture sensor was used for quick and high measurement, and unit-water content of mortar was evaluated through machine running and deep running based on measurement big data. The multi-input deep learning model is as accurate as 24.25% higher than the OLS linear regression model, which shows that deep learning can more effectively identify the nonlinear relationship between high-frequency moisture sensor data and unit quantity than linear regression.

• Journal of Environmental Impact Assessment
• /
• 제12권2호
• /
• pp.73-86
• /
• 2003

In this study, we performed 8 times of water quality sampling and continuous measurement of flow to identify wastewater flow characteristics for wastewater treatment basins of Namyangju city. The field survey has been conducted 6 times in dry weather period and 2 times in wet weather period. Each survey conducted 24-hr water quality sampling in the interval of 2-hr. From the analysis of flow data and water quality data, the following conclusions can be drawn. For Namyangju-1 station, which represents residential and commercial mixed area, flow rises early in the morning before office-going hour and moves up and down within narrow range, and lasted after office-leaving hour, resulting from continuous commercial activity. In case of Namyangju-5 station representing community and Namyangju- 6 station representing residential area, the flow immediately falls down after rising early in the morning and later rises again at the office-leaving hour, and arrives at peak flows around late evening. In the analysis of wastewater characteristics for weekdays and weekends, without landuse types the flow rate of weekends is higher than that of weekdays because it reflects population, being not contributed to generate wastewater during the working hours of weekdays, stay home and produce wastewater for weekends period.

• Proceedings of the Korea Contents Association Conference
• /
• 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
• /
• pp.391-395
• /
• 2005

In this paper, the new evaluation system for water quality pollution is implemented using fuzzy integral based on the conventional evaluation criterions and their evaluation factors and this is the first phase in the whole water quality pollution evaluation system development. In the final evaluation for water quality pollution the factors like BOD, COD, SS, T-N, and T-P are taken into overall accounts. It is found that the final evaluation can be represented in a linear combination of respective factor evaluation when each factor is independent one another, With respect to the combination patterns the fuzzy measurement is defined and the fuzzy integral is taken. As a result this approach shows stable and reliable evaluation for the water quality pollution evaluation system development.

• Journal of Korean Society of Environmental Engineers
• /
• 제36권9호
• /
• pp.629-640
• /
• 2014

In this study, the applicability of dynamic water quality model to TMDL system was examined, methods for setting of water quality goal and estimation of allocation loads were suggested and results of applying these methods were analyzed. HSPF model was applied for Miho stream basin as a dynamic water quality model. The model was calibrated using measurement data obtained in 2009~2010 and showed satisfactory performance in predicting daily variations of flow rate and BOD concentration. Methods for TMDL application were categorized into 3 cases; water quality management (1) considering low flow condition(Case I), (2) considering entire period of the year (Case II) and (3) considering the worst water quality condition (Case III). BOD water quality goals at the end of Miho stream watershed increased in the order of Case IICase I>Case III. If further researches on base precipitation and method for model input of nonpoint source pollutant were carried out, water quality could be managed more reasonably and scientifically by applying dynamic water quality model to TMDL. The result of this study is expected to be used as primary data for TMDL using dynamic water quality model.