• Title/Summary/Keyword: Grid Unit

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Calculation of Pollutant Loadings from Stream Watershed Using Digital Elevation Model and Pollutant Load Unit Factors (발생부하원단위와 수치표고모형을 이용한 하천유역 오염부하량 산정)

  • Yang, Hong-Mo;Kim, Hyuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.1
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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.

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Design for seawater reverse osmosis plant using water blending in smart water grid (스마트 워터 그리드 내에서 워터 블렌딩을 고려한 역삼투 해수담수화 플랜트 설계)

  • Lee, Hongju;Park, Hanbai;Woo, Dal-Sik;Kim, Suhan
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.1
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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.

Prediction of the Noise Levels for a Newly-founded Petrochemical Plant (신설 석유화학 공장의 소음도 예측)

  • 윤세철;이해경
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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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.

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Small Nuclear Units and Distributed Resource interconnection(2) (Small Nuclear Units에 의한 분산전원 및 계통연계(2))

  • Lee, Sang-Seung
    • Proceedings of the KIEE Conference
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    • 2005.07a
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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.

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Development of Synthetic Unit Hydrograph using River Fractal Characteristics (하천의 프랙탈 특성을 이용한 합성단위유량도의 개발)

  • 차상화
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.6
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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.

Determination of epicenters and magnitudes of future earthquakes based on the historical earthquake catalogues (역사지진 기록을 기초로한 지진규모와 위치 예측 방법)

  • 권오성;한상환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.10a
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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.

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Implement of a Watt-Hour Meter Monitoring System using Powerline Communication (전력선 통신을 이용한 전력량계 모니터링 시스템 구현)

  • Park, Keun-Soo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1143-1148
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    • 2013
  • This paper deals a watt-hour meter monitor system with applying a Power Line Communication (PLC) modem and a Data Concentrator Unit (DCU). PLC modem uses the power line, so there is no need to install dedicated wiring. This system makes it possible to monitor the amount of electricity of previous current month metering data, so it can easily apply a PC-management for the electric charges and maintenance with gathering the metering data.

A Study on the Grid Land Subdivision of Ancient Local City in Korea (고대 한국 지방도시 격자형 토지구획의 형태특성에 관한 연구)

  • Lee, Kyung-Chan
    • Journal of architectural history
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    • v.11 no.4 s.32
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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.

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PSF Deconvolution on the Integral Field Unit Spectroscopy Data

  • Chung, Haeun;Park, Changbom
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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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.

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Spatio-temporal analysis of land price variation considering modifiable area unit problem (가변적 공간 단위의 문제를 고려한 지가 변동의 시공간 분석)

  • 오충원
    • Spatial Information Research
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    • v.10 no.2
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    • pp.185-199
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    • 2002
  • The objective of this study is to investigate the suitable spatio-temporal analysis method considering the zoning effect of spatial analysis termed the modifiable areal unit problem(MAUP). In former studies of spatio-temporal analysis, there were disagreement between attribute data with spatial data, because of variation of administrative district aggregating attribute data. It is need to consider how the analysis zone effects spatial characteristics and spatio-temporal variation of urban region through land price variation analysis. This study considers MAUP through basic mesh system, which is composed of micro grid. Mesh system can solve disagreement of resolution between spatial data and attribute data.

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