• Title/Summary/Keyword: Dispersion coefficient

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Study of the Spatial Distribution of Major Non-timber Forest Products - Focusing on Chestnut, Astringent Persimmon, and Oak Mushroom - (주요 단기소득임산물의 공간적 분포 특성에 관한 연구 - 밤, 떫은감, 표고버섯을 대상으로 -)

  • KIM, Won-Kyung;LEE, Jung-Min;KWON, Soon-Duk;JEON, Jun-Heon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.19 no.2
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    • pp.73-85
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    • 2016
  • Systematic and efficient forestry management is required because of the long-term low profitability of timber production and forest products. In this situation, non-timber forest products can be the solution to secure stable sources of income for workers in the forestry field. However, the existing studies for non-timber forest products focus on effective production and economic analysis and provide plans for increasing the income and improving the marketing system. Therefore, this research intends to analyze the spatial distribution as well as quantitative concentration of non-timber forest production. To achieve this goal, this study examined the regional concentration and dispersion of non-timber forest production in 2001, 2007, and 2014 using the coefficient of localization(CL) and location quotient(LQ) and investigated the change in spatial distribution using spatial statistics. The production of chestnuts generally showed a concentrated pattern in 2014 based on the outputs of the CL and LQ, but the result of spatial autocorrelation indicated a decrease in the spatial concentration. In addition, astringent persimmon showed more concentration from the output of CL than oak mushroom, but Moran's I suggests the opposite. Therefore, it is necessary to examine the spatial distribution to understand and improve the marketing system and intensify the production of forest products.

Refractive index change of nonlinear polymer thin films induced by corona poling and quantitative evaluation of poling effect (코로나 극성배향이 비선형 고분자박막의 복소굴절율에 미치는 영향 및 배향효과의 정량화)

  • 길현옥;김상준;방현용;김상열
    • Korean Journal of Optics and Photonics
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    • v.10 no.3
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    • pp.181-187
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    • 1999
  • We prepared the side-chain type nonlinear optical NPP(N-(6-nitrophenyl)-(L)-prolinol) polymer films by spin coating method. Ellipsometric spectra were in situ collected by using spectroscopic phase modulated ellipsometer while the NPP polymer films were being corona poled at the temperature above glass transition. We calculated film thickness and the refractive index dispersion by modeling the spectro-ellipsometry data in transparent region. We also calculated the refractive index and the extinction coefficient of the polymer films by numerically inverting the spectro-ellipsometry data in absorbing region, while the previously determined film thickness was used. The independently determined extinction coefficient spectra from the analysis of transmission spectra were compared with those by spectro-ellipsometry and they showed an excellent agreement with each other. From the analysis of the complex refractive index change of the NPP polymer thin films induced by the corona poling, we could determine the vertical complex refractive index and the horizontal complex refractive index separately. Using the volume fraction of the vertical component f⊥, the degree of poling of poled NPP polymer films was quantitatively addressed. It is suggested that the present method can be used to quantitatively address the degree of poling in an absolute manner and to depth profile the poled fraction of thick polymer films. It will be useful to understand the structural change of polymer films and hence the poling mechanism during the poling process.

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Analysis of Siting Criteria of Overseas Geological Repository (II): Hydrogeology (국외 심지층 처분장 부지선정기준 분석 (II) : 수리지질)

  • Jung, Haeryong;Kim, Hyun-Joo;Cheong, Jae-Yeol;Lee, Eun Yong;Yoon, Jeong Hyoun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.253-257
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    • 2013
  • Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper evaluated the siting criteria of overseas geological repository with related to hydrogeologic properties, such as hydraulic conductivity, partitioning coefficient, dispersion coefficient, boundary condition, and water age. Each country establishes the siting criteria based on its important geological backgrounds and information, and social environment. For example, Sweden and Finland that have decided a crystalline rock as a host rock of a geological repository show different siting criteria for hydraulic conductivity. In Sweden, it is preferable to avoid area where the hydraulic conductivity on a deposition hole scale (~30m) exceeds $10^{-8}m/s$, whereas Finland does not decide any criterion for the hydraulic conductivity because of limited data for it. In addition, partitioning coefficients should be less than 10-1 of average value in Swedish crystalline bedrock. However, the area where shows 100 times less than average partitioning coefficients of radionuclides in crystalline rock should be avoided in Sweden. In German, the partitioning coefficients for the majority of the long-term-relevant radionuclides should be greater than or equal to $0.001m^3/kg$. Therefore, it is strongly required to collect much and exact information for the hydrogeologic properties in order to set up the siting criteria.

A Study on Improvement of Air Quality Dispersion Model Application Method in Environmental Impact Assessment (II) - Focusing on AERMOD Model Application Method - (환경영향평가에서의 대기질 확산모델 적용방법 개선 연구(II) - AERMOD 모델 적용방법을 중심으로 -)

  • Suhyang Kim;Sunhwan Park;Hyunsoo Joo;Minseop So;Naehyun Lee
    • Journal of Environmental Impact Assessment
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    • v.32 no.4
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    • pp.203-213
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    • 2023
  • The AERMOD model was the most used, accounting for 89.0%, based on the analysis of the environmental impact assessment reports published in the Environmental Impact Assessment Information Support System (EIASS) between 2021 and 2022. The mismatch of versions between AERMET and AERMOD was found to be 25.3%. There was the operational time discrepancy of 50.6% from industrial complexes, urban development projects between used in the model and applied in estimating pollutant emissions. The results of applying various versions of the AERMET and AERMOD models to both area sources and point sources in both simple and complex terrain in the Gunsan area showed similar values after AERMOD version 12 (15181). Emissions are assessed as 24-hour operation, and the predicted concentration in both simple and complex terrain when using the variable emission coefficient option that applies an 8-hour daytime operation in the model is lowered by 37.42% ~ 74.27% for area sources and by 32.06% ~ 54.45% for point sources. Therefore, to prevent the error in using the variable emission coefficient, it is required to clearly present the emission calculation process and provide a detailed explanation of the composition of modeling input data in the environmental impact assessment reports. Also, thorough reviews by special institutions are essential.

The Characteristics of Heavy Metal Contamination in Tailings and Soils in the Vicinity of the Palbong Mine, Korea (팔봉광산 선광광미와 주변토양의 중금속 오염 특성)

  • 이영엽;정재일;권영호
    • Economic and Environmental Geology
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    • v.34 no.3
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    • pp.271-281
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    • 2001
  • The characteristics of the heavy metal contamination in the soils affected by the tailings of the Palbong mine have been studied. The soils in the studied area consist mostly of loam by the particle size analysis, but a little of it, located near the stream, consist of loamy sand to sandy loam, finally to loam downward. The organic contents of soils are significantly low aoom 2 percent and the pH is in acidic ranging 6.0 $\pm$ 0.1. The samples of the parent rocks, the normal soils, the tailings and the channel deposits from the studied area were chemically analysed. From the result, the heavy metal concenlration of the soils is a little Jow compared with that of the parent rocks, shows the hydrologic process of the surface and the groundwater. The contamination of the tailings from the ore mining are high in lead, copper and arsenic. In the channel deposits the concenlrations of lead and copper are abnormally high but that of arsenic is uniquely low. And most of heavy metal contamination are decreased with the distance from the mine. It is caused by the properties of the surface and the ground water during the process of the heavy metal migration. The correlation-coefficient between sand and silt contents and the concentrations of Cd, Cu and Pb are significant but the amounts of As and Hg are increased with the clay contents. The dispersion of the heavy metals with the distance shows that the concentrations of them in the soils sampled at distance of 100 m to 200 m along the stream started near the Palbong mine are extremely high compared with those from other distances. These discrepancies are significant in Cd, Cu, Pb and Hg, but low in As. All the samples contain below detection limit of Cr+6 In the present stream water the concentrations of the heavy metals are not detected. So, it is interpreted that the concentrations in the soils are caused by the activities of the mining during the operation and have been continued by the dispersion from the tailings since after the closure of the mining, especially by the surface and ground water. The concentrations are diminished with the distance from the mining site, but in the interval of 800-2000 m increases abruptly. In the soil samples counted on the dispersion direction by wind, the lowering of the concentration is relatively uniform with the distance from the mining site. So, the rapid increase of the heavy metal concentrations is presumed to have been caused by the ground-water movement. In the migration of the heavy metals, the groundwater conditions, such as pH, Eh, the contents of colloidal particles, and Mn and Fe oxides are closely involveo. Integrating with these factors, it is interpreted that the groundwater conditions which have caused the heavy metal contamination of the studied area are those that the pH is about 3 in oxidized conditions, the contents of the colloidal particles are low, and Mn and Fe oxides are not involved in the migration of the heavy metals. Meanwhile, the vegetables growing on the soils in the studied area are not affected by the contamination of the heavy metals.

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Seasonal Variation of Thermal Effluents Dispersion from Kori Nuclear Power Plant Derived from Satellite Data (위성영상을 이용한 고리원자력발전소 온배수 확산의 계절변동)

  • Ahn, Ji-Suk;Kim, Sang-Woo;Park, Myung-Hee;Hwang, Jae-Dong;Lim, Jin-Wook
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.52-68
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    • 2014
  • In this study, we investigated the seasonal variation of SST(Sea Surface Temperature) and thermal effluents estimated by using Landsat-7 ETM+ around the Kori Nuclear Power Plant for 10 years(2000~2010). Also, we analyzed the direction and range of thermal effluents dispersion by the tidal current and tide. The results are as follows, First, we figured out the algorithm to estimate SST through the linear regression analysis of Landsat DN(Digital Number) and NOAA SST. And then, the SST was verified by compared with the in situ measurement and NOAA SST. The determination coefficient is 0.97 and root mean square error is $1.05{\sim}1.24^{\circ}C$. Second, the SST distribution of Landsat-7 estimated by linear regression equation showed $12{\sim}13^{\circ}C$ in winter, $13{\sim}19^{\circ}C$ in spring, and $24{\sim}29^{\circ}C$ and $16{\sim}24^{\circ}C$ in summer and fall. The difference of between SST and thermal effluents temperature is $6{\sim}8^{\circ}C$ except for the summer season. The difference of SST is up to $2^{\circ}C$ in August. There is hardly any dispersion of thermal effluents in August. When it comes to the spread range of thermal effluents, the rise range of more than $1^{\circ}C$ in the sea surface temperature showed up to 7.56km from east to west and 8.43km from north to south. The maximum spread area was $11.65km^2$. It is expected that the findings of this study will be used as the foundational data for marine environment monitoring on the area around the nuclear power plant.

An Analysis of the Visual Characteristics and Preference Factors of Traditional Landscape of Rivers in Kangnam Region of China - With a Case of River in Zhouzhuang, Jiangsu Province of China - (중국 강남 전통 수향(水鄕) 하천 경관의 시각적 특성 및 선호요인 분석 - 중국 강수성 주장(周莊) 하천경관을 중심으로 -)

  • Kim, Dong-Chan;Song, Mei-Jie
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.3
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    • pp.122-130
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    • 2010
  • The Study takes the rivers in Zhouzhuang - traditional Chinese Kangnam watery landscape as the object. The purpose of this study is to grasp the relationships between visual characteristics and the preference. The following is the research process: Firstly, the theoretical study of Zhouzhuang, the traditional Kangnam region in China, is conducted, the watery landscape is taken pictures, and 22 photos are selected. Secondly, in order to grasp the visual preference and landscape characteristics of the watery landscape in Zhouzhuang, 22 pictures and 25 pairs of adjectives are adopted for the questionnaire survey. Thirdly, in order to have a better understanding on the physical properties and effects of physical quantity on the preference, the occupation ratios of buildings and sculptures, natural elements, footpaths, bank revetments and other landscape elements are calculated, and the mean analysis, dispersion analysis and regression analysis are conducted. In order to grasp the landscape characteristics and preference factors, 25 pairs of adjectives are used to conduct the factor analysis. In order to grasp the effects of characteristics of visual factors on the preference, the dispersion analysis and regression analysis are carried out. The results are as follows: From the results of the landscape preference analysis, in the No.22 photo with the top preference, 11 pairs of adjectives, namely, "harmonious-disharmonious", "beautiful-ugly", "rural-urban", "soft-rough", "stable-instable", "romantic-realistic", "cheerful-gloomy", "brilliant-simple", "natural-artificial", "familiar-strange", and "clean-dirty" have positive effects on watery landscape. It can be viewed as the relatively important factor in the visual preference. In terms of the results of visual physical quantity analysis of traditional Chinese Kangnam watery landscape, the landscape with high occupation ratio of buildings and sculptures has positive effects on visual preference. The results of analysis of visual physical quantity and preference show that the preference degree increases as the occupation ratio of footpath area increases. The analysis results of visual characteristics of traditional Chinese Kangnam watery landscape identify four factors, namely psychological factor, cultural factor, condition factor and physical factor. It can be concluded from the results of analysis of the relationships between visual preference and visual characteristics that the return coefficient B of the psychological factor is +0.936. It can significantly affect the watery landscape, so it can be identified as the most important factor among the visual preference factors of Chinese Kangnam watery landscape.

A Study on the Ripple Effect of Physical Distribution Service Industry on National Economy (물류서비스 산업의 국민경제적 파급효과 분석)

  • Jeong, Boon-Do;Hong, Geum-Woo
    • Journal of Korea Port Economic Association
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    • v.24 no.2
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    • pp.193-208
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    • 2008
  • This study aims to analyse the ripple effect of Physical distribution service industry on national economy using input-output tables and present the results as data for political plans in this field. For the analysis, it uses input-output tables developed and published by Sank of Korea in 1998, 2000, and 2003. To sum up the results, production inducement effects are 1757 for railroad transport, 1688 for road transport and 1617 for loading. Import inducement effects of assistant services, loading, storage, warehouse and other transport-related services are low while the effects of water and air transport are high as follows: 0.679 and 0.558 respectively. Then, added-value inducement effects are presented as follows: 0.841 for railway transport, 0.828 for road transport, 0.962 for transport assistant service, 0.939 for loading, 0.938 for storage and warehouse, and 0.942 for other transport-related services. Sensitivity dispersion index of road transport is high while that of water transport, storage and warehouse is low. And influence coefficient of railway and road transport is high while that of water and air transport is low. In respect to the employment structure of Physical distribution service industry, 744,000 are employed for road transport industry, which is the largest number, 19,000 for air transport and 20,000 for assistant services, which is the least number.

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The Characteristics of Hydrogeological Parameters of Unconsolidated Sediments in the Nakdong River Delta of Busan City, Korea

  • Khakimov, Elyorbek;Chung, Sang Yong;Senapathi, Venkatramanan;Elzain, Hussam Eldin;Son, JooHyeong
    • Journal of Soil and Groundwater Environment
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    • v.22 no.3
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    • pp.27-41
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    • 2017
  • This study dealt with the characteristics and the interrelations of hydrogeological parameters such as hydraulic conductivity, dispersivity and effective porosity of unconsolidated sediments for providing the basic data necessary for the planning of the management and preservation of groundwater quality in the Nakdong River Delta of Busan City, Korea. Groundwater quality in this area has been deteriorated due to seawater intrusion, agricultural fertilizer and pesticide, industrial wastewater, and contaminated river water. The physical properties (grain size distribution, sediment type, sorting) and aquifer parameters (hydraulic conductivity, effective porosity, longitudinal dispersivity) were determined from grain size analysis, laboratory permeability test and column tracer test. Among 36 samples, there were 18 Sand (S), 7 Gravelly Sand (gS), 5 Silty Sand (zS), 5 Muddy Sand (mS), and 1 Sandy Silt (sZ). Hydraulic conductivity was determined through a falling head test, and ranged from $9.2{\times}10^{-5}$ to $2.9{\times}10^{-2}cm/sec$ (0.08 to 25.6 m/day). From breakthrough curves, dispersivity was calculated to be 0.35~3.92 cm. Also, effective porosity and average linear velocity were obtained through the column tracer test, and their values were 0.04~0.46 and 1.06E-04~6.49E-02 cm/sec, respectively. Statistical methods were used to understand the interrelations among aquifer parameters of hydraulic conductivity, effective porosity and dispersivity. The relation between dispersivity and hydraulic conductivity or effective porosity considered the sample length, because dispersivity was affected by experimental scale. The relations between dispersivity and hydraulic conductivity or effective porosity were all in inverse proportion for all long and short samples. The reason was because dispersivity was in inverse proportion to the groundwater velocity in case of steady hydrodynamic dispersion coefficient, and groundwater velocity was in proportion to the hydraulic conductivity or effective porosity. This study also elucidated that longitudinal dispersivity was dependent on the scale of column tracer test, and all hydrogeological parameters were low to high values due to the sand quantity of sediments. It is expected that the hydrogeological parameter data of sediments will be very useful for the planning of groundwater management and preservation in the Nakdong River Delta of Busan City, Korea.

TRANSPORT AND DIFFUSION OF POLLUTANTS IN THE COASTAL WATERS OF ONSAN INDUSTRIAL COMPLEX (온산공단 부근의 해양오염물질 이동)

  • CHANG Sun-duck;LEE Jong-Sub;HAN Kyeong-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.151-162
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    • 1980
  • To clarify the dispersion of pollutants introduced in the coastal region, a series of current measurements, the drogue and drift bottle experiments as well as the dye diffusion experiments were carried out in Onsan Bay and in the coastal waters of Ubong-ri near Ulsan. In the southeastern coastal region of Korean peninsula, that is, in the outside of Onsan Bay, the flood tidal current flows south-south-westward, and the ebb current flows north-north-eastward at a maximum speed of 1.0-1.1 knots at spring tide. In an inlet south of Cape Ubong, an anticyclonic eddy of 1 km in diameter is usually formed during both flood and ebb flows. The tidal current predominates in Onsan Bay at around spring tide. The maximum speed around spring tide was observed to be approximately 0.14 knot, while it was slower than 0.1 knot and variable at neap tide when the wind drift current played an important role. The flood tidal current flows westward while the ebb flow flows eastward in the northern region of the bay. The flood tidal current in the southern region of the bay flows west-north-westward, while the ebb current east-north-eastward. Wind drift currents in the coastal region of southern Korea are generally deduced to be southward in winter, the monthly mean speed being approximately 0.1 knot. Dye solution released at the northwestern corner in Onsan Bay was transported by eastward ebb tidal current toward the mouth of the bay dispersing by the wind. The apparent diffusion coefficient at 150 minutes after release in the bay was calculated to be $4.4\times10^4\;cm^2.sec^{-1}$, whereas that in the anticyclonic eddy was more or less smaller.

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