• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.83-84
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• 2014

For hydrologic applications, lake levels is very important. As a first step in developing a remote-sensing based approach, lake stage estimation using remote sensing was proposed with the SRTM data from February 2000, which was providing a one-time snapshot. After several steps using contouring, masking, and CED, it was found that iterative contour fitting to a lake outline provided the outstanding result with the operator's decision. If the lake size is large enough, a constant meter of the difference removal due to bias found by Bhang et al. (2007) might be useful for more accurate estimations for the methods. A lake-level snapshot using SRTM data could provide estimates within 0.5 m level of accuracy for large lakes (> $10km^2$) with contouring. Also, even if the processing algorithm is complex, the accuracy was reliable. Overall, we confirmed that this study would provide useful information to ameliorate the quality of the SAR-derived DEMs specifically for water areas and if more expanded, SAR images can fruit result in water monitoring.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.2011-2015
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• 2006

본 연구에서는 시공간을 고려하여 경안천유역의 최적 수질 측정망을 구성하였다. 분석을 위해서 필요한 수 질 데이터는 QUAL2E 모형을 이용하여 모의하였으며, 매개변수의 추정을 위하여 HEC-RAS모형과 민감도 분석 기법인 1차 신뢰성 분석(FORA)를 사용하였다. QUAL2E 모형의 모의 결과를 바탕으로 크리깅 기법과 Branch and Boundary Method를 이용하여 평수량 일때와 갈수량 일때로 구분하여 관측지점의 개수와 위치를 제시하였다. 선정된 지점을 기준으로 비례표본추출법(proportional sampling method)을 이용하여 각각의 지점별 측정 빈도를 제시하였다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.299-304
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• 1998

Flood control of the Mekong delta should be developed over time for rural as well as urban areas. The hydraulic modelling effort is aimed an investigating flow distribution and water level. For the flood control study the flood model made with the VRSAP program is used. Concerning future improvement of the models it is recommended to improve the quality of water level and discharge, extend the number of the measuring locations needed for input for the models, systematically review and analyze future measurement campaigns in order to obtain better understanding of the complex hydraulic aspects, verify and update the topographical data used to model the rivers and cannals, carry out detailed calibration and verification of the models on water levels, discharges etc.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1398-1405
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• 2008

As the structure, material and construction of building develop continuously, so the recent residential buildings are being large, high-rise and group. High-rise residential buildings consume a lot of energy on supplying cold and hot water. As well, high-rise residential buildings bring on discomfortable use and unexpected conditions on account of faucet outlet pressure rise and the difference of water supply pressure between top floor and bottom floor. Thus, the purpose of this study is to research on using conditions of cold and hot water supply system through survey and field measurement in high-rise residential buildings and to analyze problems.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.85-86
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• 2018

In this study, we previously conducted a quick evaluation of cement powder map using mesiline and hydrometer. The experiment also confirmed the possibility of rapid quality evaluation of cement powder. In this study, further studies have been conducted to apply speed and cost more economical than conventional methods, and the possibility of applying this research is to be analyzed. The result of the experiment was 500 mL of a bottled water bottle with a solid edge for measurement convenience, and the hydrometer was determined to be B type. In addition, density values of each other by powder during the same time period are considered to be measurable, indicating large differences.

• Asian Journal of Turfgrass Science
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• v.17 no.2_3
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• pp.87-97
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• 2003

The growth characteristics of creeping bentgrass seeded in the seaside landfill golf course are as follows. 1. As a result of analysis on the chemical characteristics of soil mixture used for turfgrass ground in this experiment, soil pH was 7.9, which is somewhat higher than the creeping bentgrass reference value of pH 5.5∼6.5; T-N(%) was 0.02, which is proper for the reference value, and trace element too lacked. 2. The cultivar with the fastest water infiltration was Seaside II recorded as 226.2cm/sec, while that with the slowest water infiltration was Pennlinks recorded as 141.1 cm/hr which was too faster than the USGA water infiltration reference value of 15∼30cm/hr. For the surface hardness of turfgrass ground with different cultivars, no statistically significant variation was found between the Penncross grass and the Pennlinks recorded as 18.6mm and 19.1 mm, respectively. The soil penetration was the highest in Pennlinks recorded as 7.6kg/$\textrm{cm}^2$ and lowest in Penn A-1 as 6.1kg/$\textrm{cm}^2$. 3. As a result of evaluation on visual quality at the early stage of growth, Penncross showed the most excellent visual quality compared to the others. However, Penn A-1 showed the most excellent visual quality at a late stage of growth around Sep. 17, 2003, and it was also excellent in the evaluation of visual color. Seaside II showed higher density around the root and the longest root length and was highly resistant to salt compared to others, but the initial sprouting rate was not satisfied, and the visual quality in the summer season was inferior to others. 4. As a result of measurement of the traffic injury, Penncross showed the most tolerant to the traffic stress and Pennlinks showed the most susceptible.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.161-168
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• 2007

The main aim of this work is focus on the Geum river water quality evaluation of pollution data obtained by monitoring measurement during the period 2001-2005. The complex data matrix 19 (entire monitoring stations)*13 (parameters), 60 (month)*13 (parameters) and 20 (season)*13 (parameters) were treated with different multivariate techniques such as factor analysis/principal component analysis (FA/PCA). FA/PCA identified two factor (19*13) classified pollutant Loading factor (BOD, COD, pH, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P, Chl-a), seasonal factor (water temp, SS) and three Factor (60*13, 20*13) classified pollutant Loading factor (BOD, COD, Cond, T-N, T-P, $NH_3$-N, $NO_3$-N, $PO_4$-P), seasonal factor (water temp, SS) and metabolic factor (Chl-a, pH). Loadings of pollutant factor is potent influence main factor in the Geum river which is explained by loadings of pollutant factor at whole sampling stations (71.16%), month (52.75%) and season (56.57%) of main water quality stations. Result of this study is that pollutant loading factor is affected at Gongju 1, 2, Buyeo 1, 2, Gangkyeong, Yeongi stations by entire stations and entire month (Gongju 1, Cheongwon stations), April, May, July and August (buyeo 1) by month. Also the pollutant Loading factor is season gives an influence in winter (Gongju 1, buyeo 1) from main sampling stations, but Cheongwon characteristic is non-seasonal influenced. This study presents necessity and usefulness of multivariate statistic techniques for evaluation and interpretation of large complex data set with a view to get better information data effective management of water sources.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.24-30
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• 2018

Objectives: Based on the amount of amalgam, the duration of exposure, and the water pH, this study aims to investigate the change patterns in the mercury concentrations in water after amalgams have been introduced into sewage water. It is expected that the study results will be useful in improving the system for regulating the amount of mercury that is introduced into the environment. Methods: During the study, a glass test-tube with a cap was washed and disinfected using the glass laboratory device washing method. Then, 1, 2, 3, and 4 tabs were placed into a 10 mL pH 4 solution and 10 mL pH 7 distilled water. Each specimen was prepared in duplicate. The mean of the two mercury concentrations was used as the representative value, and the mercury concentration was measured using a mercury measurement device (DMA-80, Milestone, Italy) a total of eight times at one-week intervals. Results: The results show that the lower was the pH, the higher was the amount of amalgam. Also the longer was the duration, the more significant was the increase of mercury concentration in the water. Conclusions: Dental clinics are collected separately from dental clinics that used them. Given this, dental clinics in Korea must have the necessary facilities to separately collect mercury at their level. In addition, proper disposal systems and social attention to the proper management of dental wastes are required to prevent environmental pollution from mercury.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.522-525
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• 1985

The dried soymilk residue (SMR) was added into soybean water extract in order to investigate its effect on physical characteristics of soybean curd. As the mixing ratio (d. b.) increased, the volume and water holding capacity of the curd was reduced and penetration value was increased. However, the Sag value was rather increased until 20% of mixing ratio reached and then decreased drastically by 30% addition of SMR. The overall physical and sensory quality showed that substitution of soybean with SMR by 10% was recommendable without significant unfavorable change in quality of soybean curd. The proposed method of absorption of unbound water on filter paper was proved to be simple and reliable for measurement of water holding capacity of soybean curd.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.275-280
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• 2007

The effect of using Korean wheat flour versus Australian wheat flour on noodle quality as a result of differing physical and chemical properties of the flours was investigated. The results provided appropriate technical information for selection of wheat varieties to produce high quality Korean salted noodles. Noodle quality was quantified based on measurement of the appearance and texture of noodles. When consumer preference tests were conducted, a firmer and more elastic texture was preferred for Korean white salted noodles, however, when appearance was included in the consumer tests, noodles made with Australian wheat were favored over Korean wheats. Korean flour was found to produce firmer and more elastic noodles, whereas Australian flour produced brighter, creamier colored noodles. In flour quality tests, Korean flours were found to have a higher setback viscosity and lower swelling power than Australian flour. Additionally, Korean flours had higher water absorption values. Protein content of flour was an important parameter affecting the firmness of Korean noodles, whereas setback viscosity and swelling power were the major determinants of elasticity. Overall, the important parameters for determination of the quality of Korean salted noodles were high setback viscosity, low swelling power, and high protein content.