• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.370-378
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• 2003

Continuous seismic refraction, reflection and echo-sounder surveys conducted at Koyna Project site provided geotechnical information which helped in choosing the alignment for Head race tunnel and in designing and choosing the site for Lake Tap. Seismic refraction survey both on land and in shallow water determined depths to bedrock and helped in inferring the bedrock quality. Seismic reflection survey mapped the subsurface stratigraphy with high resolution. Reservoir-bed and bedrock contours drawn from the results of the survey helped in choosing the tunnel alignment and the lake tap position cost effectively. It was inferred from the results of the survey that the geology and the quality of rock do not change unexpectedly around the site for extension of Head race tunnel and the lake tapping. The bedrock levels evaluated by seismic survey agreed remarkably well with those inferred in boreholes having Rock Quality Designation 90 percent or more.

• ALGAE
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• v.20 no.3
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• pp.197-205
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• 2005

Temporal variability in lake phytoplankton is controlled by a complex between hydrological and chemical factors, and biological interactions. We explored annual change of phytoplankton in Lake Daecheong, using phytoplankton analysis data from 1997 to 2002 (except 2000). The standing crop of phytoplankton was ranged from 3.5 x 10 to 1.5 x 106 cells mL$^{-1}$ and the highest mean value was at site 1. The class composition ratios of phytoplankton standing crop were divided into three classes. From January to March, diatoms showed a dominance (68.1-77.7%). From April to June, diatoms were mixed with cryptomonad etc. or blue-green algae. From July to October, blue-green algae showed a dominance (54.7-84.0%). In the case of green algae, the class composition ratios were below 10%. But green algae appeared all the year round.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.2
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• pp.97-107
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• 1996

This study was performed to derive the formula of sediment yield and predict the sediment elevation for fresh desalted reservoirs. Data analyzed was from 3 fresh desalted reservoirs of Sapkyo, Asan, and Namyang. Average sediment yield calculated from the sediment survey data was $279m^3/km^2/$ year for Sapkyo lake, $523m^3/km^2/$ year for Namyang lake, and $190m^3/km^2/$ year for Asan lake. The trap efficiency for Sapkyo lake was 63%. The formula of sediment yield was derived as $Q_s=6,461{\times}A{^-0.44}$ for fresh desalted reservoir. Sediment yield in fresh desalted reservoirs was much higher than that in inland reservoirs located in the same watershed, because of long trap time in fresh desalted reservoirs.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.23-23
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• 2004

Four times of field survey were carried out to collect fish samples at six stations in Shinpo district, North Korea in October 1997, July 1998, May and October 2002. Sampling stations were located in upstream, middle and down of the southern river of Bukchong and three brackish lakes of lake Hommanpo, Daein and Hyunkum, respectively. A total of 29 species belonging to 11 families occurred. Family Cyprinidae showed the prosperity in species number of 28% among total species occurred. No natural monument fishes or rare species were captured. Ten commercial fishes, five anadromous ones and five brackish ones were identified. Feeding habits divided fish fauna with 11 carnivores, two herbivores and seven omnivorous ones. In the river, 20 species belonging to seven families inhabited, 18 species of 6 families in lake Homanpo, 21 of seven III Hyunkum and 23 of eight in Daein, respectively. Ecological indices of richness, diversity and evenness were highest in lake Daein and dominance index was highest in lake Hyunkum.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.665-672
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• 2008

It is necessary to implement the management plan for the production of safe and high quality drinking water from lake Paldang. To set up the plan, the water quality items such as BOD, T-P, SS and coliform were monitored for ten years, 1997~2006, and the influence of raw water quality on the drinking water treatment process and the treated water quality was also evaluated from 2004 to 2006. In conclusion, water quality items such as turbidity(SS), T-P(eutrophication), pathogens(fecal coliforms, enterovirus, reovirus, giardia, cryptosporidium), DOC(precursor of disinfection by-products), and micro-pollutants(phthalates, VOCs, heavy metals) are should be managed to get safe and high quality drinking water from lake Paldang.

• Proceedings of the Korean Environmental Health Society Conference
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• 2001.11a
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• pp.64-69
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• 2001

The present work provides a result from the preliminary experiment for hydrocyclone technology. In this work, local lake sediments and waste coal fly ash were used as test samples, prior to the application of hydrocyclone technology to the waste sludge thickening. A few cyclones based on the Rietema standard geometry were prepared. Chemical analysis of the sediments showed that more organic contaminants were in smaller particles. The experimental tests further showed that physical characteristics of particles, configuration of the cyclone and operation condition would affect the separation efficiency. The current results showed that small size cyclones might improve the separation and concentration of the lake sediments, and higher inlet velocity would increase the concentration rate of under flow and absolute concentration of sediment particles.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.31-34
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• 2018

We live in the digital era, and the characteristics of our customers in the digital era are constantly changing. That's why understanding business requirements and converting them to technical requirements is essential, and you have to understand the data model behind the business layout. Moreover, BI(Business Intelligence) is at the crux of revolutionizing enterprise to minimize losses and maximize profits. In this paper, we have described a leading study about the situation of desk-top BI(software product & programming language) in aspect of front-end side and the Data Lake platform based on Big Data by data modeling in aspect of back-end side to support the business intelligence.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.39-41
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• 2003

Pollen and spores as well as their morphological characteristics are biological stability materials in which contains historical information about vegetation and climate changes. As noted researcher Neishtadt in 1971, the lake and swamp deposits were developed only in Holocene period. The geological history of Darkhad depression which is situated in the Northern end of Mongolia from ancient time become under scientific interest of many researchers. Our investigation was focused on pollen analysis of lake sediment of Darkhad depression which caused bottom of paleolake. In Mongolia the palynology science is beginning to develop since 1990 and in 2000 the laboratory of palynology was established at the department of Biology, State Pedagogical University of Mongolia. Researchers from this laboratory working on pollen morphology of present flora in order to classify plants taxonomy. Another part of our investigation is mellitopalynology, which is studying of pollen grains in a honey. Although, this research has been extending by pollen analysis of sediment and lake deposits in past few years on the basis of high sensitive microscope and modem technology.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.05a
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• pp.45-45
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• 2002

• ALGAE
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• v.18 no.1
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• pp.1-12
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• 2003