• Journal of Environmental Science International
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• v.14 no.1
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• pp.53-60
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• 2005

The concentrations of volatile organic compounds(VOCs) in the ambient air were measured at various point(Source, source boundary) in Seongseo industrial complex during May to November 2003. Air samples were collected in Silcocan canister $(1{\ell},\;6{\ell})$ and analyzed using a cryogenic preconcentration system and GC/MSD. We identified 37 species by the US EPA(TO-14 method). The result showed a variety distribution of the con­centration, Higher concentrations of BTX, Styrene, 1,3,5-Trimethylbenzene, 1,2,4-Trimethylbenzene were observed at the sampling sites. They seemed to be emitted from the facility of wastewater treatment, reaction tank of chemistry factory and facility of Tenter. The concentrations of VOCs contents in Seongseo industrial complex were generally higher than those in Yeosu complex and Ulsan complex, although those were similar in Sihwa­Banwol complex.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.631-636
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• 2009

This study has its intention to investigate the water quality of non-point source which is runoff from roads. We have classified and selected twelve sites as city road, industrial road, national road and mountain road by considering their traffic volume and surroundings. Water quality was analyzed based on BOD, COD, SS, T-N and T-P and the concentrations were measured by sampling after rainfall with the interval of 10 minutes, 20 minutes, and 30 minutes. BOD was the highest in city road with 57.6 mg/L and the lowest in mountain road with 45.0 mg/L. For COD, the highest concentration in industrial road was 146.5 mg/L and the lowest was in mountain road with 98.0 mg/L. The run off concentration of SS was up to maximum 630.0 mg/L (average 280.4 mg/L) which was remarkable compared to other types of road. It showed its lowest concentration in national road with 76.0 mg/L. T-N and T-P were the highest in industrial road and the lowest in mountain road. We found out that the runoff concentration was high with large amount of traffic volume and it seemed to be high in city road and industrial road where they were largely affected by their surroundings. Relatively, national road and mountain road seemed to show low concentration as they have less traffic volume and less affected by their surroundings.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.215-216
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• 2014

This paper proposes a control algorithm for permanent magnet synchronous generator with a back-to-back three-level neutral-point clamped voltage source converter in a medium-voltage offshore wind power system under unbalanced grid conditions. The proposed control algorithm particularly compensates for the unbalanced grid voltage at the point of common coupling in a collector bus of offshore wind power system. This control algorithm has been formulated based on the symmetrical components in positive and negative rotating synchronous reference frames under generalized unbalanced operating conditions. Instantaneous active and reactive power are described in terms of symmetrical components of measured grid input voltages and currents. Negative sequential component of ac input current is injected to the point of common coupling in the proposed control strategy. The amplitude of negative sequential component is calculated to minimize the negative sequential component of grid voltage under the limitation of current capability in a voltage source converter. The proposed control algorithm makes it possible to provide a balanced voltage at the point of common coupling resulting in the generated power of high quality from offshore wind power system under unbalanced network conditions.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.493-505
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• 2013

This study was to investigate the runoff characteristics of non-point pollutants source at the urban area in Suwon city. The highest T-N and T-P concentration of rainfall runoff observed in agricultural area. In residential area, the highest $BOD_5$ and SS concentration of rainfall runoff was investigated. During rainfall events, the peak concentrations of SS and $BOD_5$ were observed after 1~2 hours of rainfall in urban area. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentrations of SS and $BOD_5$ sharply decreased, showing strong first flush effect in urban area. The EMC results indicated that the highest value of T-N and T-P in agricultural area was observed. While residential area was shown the lowest EMC value as T-N and T-P. Non-point pollutant loads on the land use types in urban area were investigated in the order of residential>industrial>agricultural>highway. $BOD_5$ and SS loads on urban watershed were investigated in the order of Suwon>Hwangguji>Seoho>Wonchunri. Whereas, T-N and T-P loads on urban watershed were investigated in the order of Hwangguji>Suwon>Wonchunri>Seho.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.34-46
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• 2008

Emissions inputs for use in air quality modeling of Korea were generated with the emissions inventory data from the National Institute of Environmental Research (NIER), maintained under the Clean Air Policy Support System (CAPSS) database. Source Classification Codes (SCC) in the Korea emissions inventory were adapted to use with the U.S. EPA's Sparse Matrix Operator Kernel Emissions (SMOKE) by finding the best-matching SMOKE default SCCs for the chemical speciation and temporal allocation. A set of 19 surrogate spatial allocation factors for South Korea were developed utilizing the Multi-scale Integrated Modeling System (MIMS) Spatial Allocator and Korean GIS databases. The mobile and area source emissions data, after temporal allocation, show typical sinusoidal diurnal variations with high peaks during daytime, while point source emissions show weak diurnal variations. The model-ready emissions are speciated for the carbon bond version 4 (CB-4) chemical mechanism. Volatile organic carbon (VOC) emissions from painting related industries in area source category significantly contribute to TOL (Toluene) and XYL (Xylene) emissions. ETH (Ethylene) emissions are largely contributed from point industrial incineration facilities and various mobile sources. On the other hand, a large portion of OLE (Olefin) emissions are speciated from mobile sources in addition to those contributed by the polypropylene industry in point source. It was found that FORM (Formaldehyde) is mostly emitted from petroleum industry and heavy duty diesel vehicles. Chemical speciation of PM2.5 emissions shows that PEC (primary fine elemental carbon) and POA (primary fine organic aerosol) are the most abundant species from diesel and gasoline vehicles. To reduce uncertainties in processing the Korea emission inventory due to the mapping of Korean SCCs to those of U.S., it would be practical to develop and use domestic source profiles for the top 10 SCCs for area and point sources and top 5 SCCs for on-road mobile sources when VOC emissions from the sources are more than 90% of the total.

• Journal of Korean Society of societal Security
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• v.3 no.1
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• pp.51-60
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• 2010

This study measured for comparison and analysis the correlation of River pollution and Soil contamination, based on the results of previous research, and then in order to increase the efficiency of study, heavy metals which cause serious side effects was limited to the case among pollutants. This study focused on the rivers that near the Urban and industrial districts, for example, Nak-Dong river, An-Yang river, Tae-Hwa river and the rivers that near the farm land or pasture, for example, Yeong-San river, Mi-Ho river, then compare and analyze the degree of actual pollution as gathered the results of Previous research. Correlationship about pollutants of river near the Urban, industrial area and drainage basin its river has been proven, and this expected because of the strong influence by point pollution source. On the other hand, I can found the opposite relationship where the river near the farm land or pasture, and this probably because of the influence by nonpoint pollution source.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.605-613
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• 2006

Discharge characteristics of non-point source pollutant and load amount of the discharge in the urban area were investigated in the Pungyeongjeong-stream basin and the Yongbong-stream basin in this present study. The land use of the studied basins were divided into paddy field, industrial complex area, combined sewage system, separate sewer system and point sources discharge. The descriptive statistics on the event mean concentrations (EMCs) of non-point pollutants by the the land use showed in the range of 4.43-32.28 mg/L for BOD and 8.27~56.17 mg/L for COD. The highest concentration was shown from the combined sewage system. The EMC of SS at the paddy field in the Pungyeongjeong-stream basin showed the highest range with the values ~ from 35.76 to 358.86 mg/L, which might have been influenced by a levee construction in the adjacent of the area. The relatively high concentration values of 4.43~32.28 mg/L and 1.617.13 mg/L emerged from TN and TP,respectively, at the discharge points of the both stream basins.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.768-777
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• 2009

The characteristics of stormwater runoff was examined on distinct types of agricultural and industrial area in Lake Sihwa watershed. During rainfall event, the peak concentrations of SS, $COD_{Mn}$, and TP were observed after 6~11 hours of rainfall in agricultural areas. Whereas, the peak concentrations occurred within the first one hour after rainfall and then the highest concentration of NPS pollutants sharply decreased, showing strong first flush effect in industrial areas. The strong first flush effect of suspended solid was apparent in agricultural areas, while those of organic matters and nutrients were clear in industrial areas. The cumulative load curves for NPS pollutants showed above the $45^{\circ}$ straight line, indicating that first flush effect occurred in industrial areas. The mean SS EMC values of agricultural areas ranged from 60~598 mg/L (Avg. 285 mg/L), it was higher value when compare to other areas. While the mean $COD_{Mn}$, TN, and TP EMCs values of industrial areas were shown the highest values as 67.7 mg/L, 12.1 mg/L and 2.1 mg/L respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.311-318
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• 2021

Underwater, signals are transmitted by sound waves. Sound waves are transmitted through a multipath, either directly or through reflection, due to the variety of underwater environmental characteristics. In such diverse and complex underwater environments, tests must be conducted to determine the extent of the hazard from the survivability and pitfalls of submarines by measuring the underwater radiated noise. Usually, the sound source level measurement of underwater radiated noise should be made within the closest point (CPA: Closest Point of Approach) ± a few meters between the measurement sensor and the submarine. In this study, FDOA and TDOA methods were proposed to estimate the underwater source range. A simulation based on the underwater channel model confirmed the performance of the proposed method.

• 한국기계연구소 소보
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• s.20
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• pp.21-26
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• 1990

In order to satisfy the industrial requirements to measure the rotational error motion of main spindles and to find out the source of the error motion, some measuring systems were made. Their measuring principle are based on the 3-point roundness measurement. In these measuring systems, the measurements are processed by digital calculation technique and the form error and the rotational error motion of main spindles are spearated. In the present paper, the principle of 3-point metnod is introduced and some application examples are shown.