• 해양환경안전학회지
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• 제28권6호
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• pp.890-898
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• 2022

해상공사에서 발생하는 부유사는 해수의 탁도를 증가시키고 광량을 감소시켜 해양생물에 악영향을 미치므로 해양환경영향평가에서 중요한 요소이다. 하지만 평가에 적용되는 인자에 대한 공식적인 자료의 부족과 평가자의 능력에 따라 그 영향이 달리 평가되고 있다. 따라서 본 연구에서는 해역이용영향평가센터에서 검토한 3년간(2012-2014)의 매립, 준설, 외곽시설물 설치 등 총 58건 사업에 대한 부유사 확산 평가에 대한 실태를 진단하고 개선방안을 제시하였다. 개선방안 제시를 위해 4가지의 평가지표(격자체계의 적정성, 원단위의 적정성, 대표입경 및 침강속도의 적정성)를 적용하였다. 각 항목별 신뢰도에 평균점수 분석결과, 격자체계는 25점, 원단위는 60점, 대표입경은 34점 그리고 침강속도는 17점으로 평가항목에 대한 개선방안이 필요한 것으로 나타났다. 본 연구에서는 부유사 확산 평가상태에 대한 진단 및 신뢰도 평가 결과를 활용하여 부유사 확산예측에 대한 개선방안을 제안하였다. 먼저, 부유사 발생원단위 및 대표입경별 침강속도에 대한 공신력 있는 값이 가이드라인을 통해 제공해야 한다. 그리고 실무에선 신뢰성 향상을 위해 격자체계의 적정성과 결과의 검증을 철저히 해야 한다.

• 한국조경학회지
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• 제29권1호
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• pp.22-31
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• 2001

The purpose of this study is to compare calculated pollutant loadings using pollutant load unit factors and vector type coverage, and expected mean concentration(EMC) and raster type of digital elevation model(DEM). This study is also focusing on comparison of the advantages and the disadvantages of the two methods, and seeking for a method of calculation of pollutant loadings using DEM. Estimation of pollutant inputs using pollutant load unit factors has limitations in identifying seasonal variations of pollutant loadings. Seasonal changes of runoffs should be considered in the calculation of pollutant loadings from catchments into reservoirs. Evaluation of pollutant inputs using runoff-coefficient and EMC can overcome these drawbacks. Proper EMC and runoff-coefficient values for the Koeup stream catchments of the Koheung estuarine lake were drawn from review of related papers. Arc/Info was employed to establish database of spatial and attribute data of point and non-point pollutant sources and characteristics of the catchments. ArcView was used to calculate point and non-point pollutant loadings. Pollutant loads estimated with either unit factors-coverages, i.e., pollutant load unit factors and vector coverages f point sources and land use, or EMC and digital elevation mode(DEM) were compared with stream monitoring loads. We have found that some differences were shown between monitoring results and estimated loads by Unit Factors-Coverage and EMC-DEM. Monthly variations of pollutant loads evaluated with EMC-DEM were similar to those with monitoring result. The method using EMC-DEM can calculate accumulated flows and pollutant loads and can be utilized to identify stream networks. A future research on correcting the difference between vector type stream using flow direction grid and digitalizing vector type should be conducted in order to obtain more exact calculation of pollutant loadings.

• 상하수도학회지
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• 제29권1호
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• pp.89-96
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• 2015

Smart water grid is a water network with communication to save water and energy using various water resources. In smart water grid, water product from the various sources can be blended to be supplied to end-users. The product water blending was reported by literatures while feed water blending has been rarely reported so far. In this work, a commercial reverse osmosis (RO) system design software provided by a membrane manufacturer was used to elucidate the effect of feed water blending on the performance of seawater reverse osmosis (SWRO) plant. Fresh water from exisiting water resource was assumed to be blended to seawater to decrease salt concentration of the RO feed water. The feed water blending can simplify the RO system from double to single pass and decrease seawater intake amount, the unit prices of the RO system components including high pressure pump, and operation risk. Due to the increase in RO plant capacity with the feed water blending, however, the RO membrane area and total power consumption increase at higher water blending rates. Therefore, a specific benefit-cost analysis should be carried out to apply the feed water blending to SWRO plants.

• 한국안전학회지
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• 제11권4호
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• pp.135-142
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• 1996

Prolonged in-plant personnel exposure to high noise levels results in permant hearing damage. There are no way to correct this hearing damage by treatment or use of hearing aids. Therefore, every employer is responsible for providing a workplace free of such hazards as excessive noise. This study was carried out to evalute and predict a given noise environment based on specific limit as the noise guarantee for a newly-founded petrochemical plant. The maximum total sound level should not exceed 85dBA in the work area, except where the area is defined as a restricted area and 70dBA at the plant boundary. Prediction of the noise levels within the plant area for a newly-founded petrochemical plant was achieved by dividing all plant area into 20m$\times$20m regular grid spaces and noise level inside the area or unit that in-plant personel exposure to high noise levels was estimated computed into 5m$\times$5m regular grid spaces. The noise level at the grid point that was propagated from each of the noise sources(equipments) computed using the methematical formula was defined as follows : $SPL_2$=$SPL_1-20log{\frac{r_2}{r_1}}$(dB) where $SPL_1$ =sound pressure level at distance $r_1$ from the source $SPL_2$=sound pressure level at distance $r_2$ from the source As a result, the equipments exceeded noise limit or irritaring noise levels were identified on the specific grid coordinates. As for equipments in the area that show high noise levels, appropriate counter-measures for noise control (by barriers, enclosure, silencers, or the change of equipments, for example) should be reviewed. Methods for identifying sources of noise applied in this study should be the model for prediction of the noise levels for any newly-founded plant.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.420-422
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• 2005

This paper introduces a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation.

• 한국농공학회지
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• 제44권6호
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• pp.61-70
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• 2002

This study was performed to analyze the river fractal characteristics using GIS (Geographic Information System). In this study, topographical factors in river basin were grid-analyzed for each cell size and scale using GIS and regression formula was derived by analyzing correlation among topographical factors and cell size which were calculated here. And, a new rainfall-runoff model which is considering the calculated fractal dimension was developed to apply fur a river basin.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.323-330
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• 2000

Three historical earthquake catalogues were compared with each other in the view of frequency of events per century, cumulative magnitude distribution, and annual earthquake occurrence rate in each unit grid of 0.1°by 0.1°. And, a method to determine earthquake epicenters and magnitudes was proposed given the historical earthquake data. With this method, the epicenters and magnitudes of future earthquakes in Korean penninsula for 1,000 years were generated with each earthquake catalogue. Earthquake PGAs with 10% exceedance probability in Seoul were calculated for each catalogue and compared.

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1143-1148
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• 2013

본 논문에서는 가정용 계량기의 데이터를 PC로 모니터링할 수 있도록, 전력선 통신(PLC : Power Line Communication) 모뎀과 데이터 수집 장치 (DCU : Data Concentrator Unit)를 적용한 시스템을 구현하였다. 전력선 통신 모뎀은 기존의 전력선에 데이터를 실어 보내는 기술로 별도의 신호선 설치에 대한 부담을 개선한다. 본 시스템은 가정용 계량기의 데이터를 수집하여, 각 가정의 전, 현 월 사용 전력량을 서버용 PC로 확인하여 요금 관리, 고장 관리를 편리하도록 한다.

• 건축역사연구
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• 제11권4호
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• pp.45-69
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• 2002

This study aims to find out the genetic characteristics of gridded subdivision area which has its origin from ancient local administrative city-Sangju, Jeonju, Namwon, Kwangju, Chungju. The spatial structure, based on the inter-relationship among gridded subdivision area, city wall, and topographic condition, and the morphological characteristics of gridded subdivision area are analyzed. The points of analysis on morphological characteristics of gridded subdivision area consist of the size of unit block, the organization system of unit block, the orientation of subdivision line. As a result of the analysis, three main characteristics are found. Firstly there can be found no same land subdivision rule among study areas. Secondly, the morphological features of study area were the products of cumulative process of different subdivision areas which were developed in different periods. Thirdly, the original regular gridded land subdivision seems to have been carried out in the object of a farm-land cultivation around 7th century. And there was a change of land-use from farm land to urban land-use during the later 7th century and 8th century.

• 천문학회보
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• 제44권1호
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• pp.58.4-58.4
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• 2019

We present the application of the Point Spread Function (PSF) deconvolution method to the astronomical Integral Field Unit (IFU) Spectroscopy data focus on the restoration of the galaxy kinematics. We apply the Lucy-Richardson deconvolution algorithm to the 2D image at each wavelength slice. We make a set of mock IFU data which resemble the IFU observation to the model galaxies with a diverse combination of surface brightness profile, S/N, line-of-sight geometry and Line-Of-Sight Velocity Distribution (LOSVD). Using the mock IFU data, we demonstrate that the algorithm can effectively recover the stellar kinematics of the galaxy. We also show that lambda_R_e, the proxy of the spin parameter can be correctly measured from the deconvolved IFU data. Implementation of the algorithm to the actual SDSS-IV MaNGA IFU survey data exhibits the noticeable difference on the 2D LOSVD, geometry, lambda_R_e. The algorithm can be applied to any other regular-grid IFS data to extract the PSF-deconvolved spatial information.