• Title/Summary/Keyword: Aggregate resource

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Three Dimensional Measurements of Pore Morphological and Hydraulic Properties (토양 공극 형태와 수문학적 특성에 대한 3 차원적 측정)

  • Chun, Hyen-Chung;Gimenez, Daniel;Yoon, Sung-Won;Heck, Richard;Elliot, Tom;Ziska, Laise;Geaorge, Kate;Sonn, Yeon-Kyu;Ha, Sang-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.4
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    • pp.415-423
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    • 2010
  • Pore network models are useful tools to investigate soil pore geometry. These models provide quantitative information of pore geometry from 3D images. This study presents a pore network model to quantify pore structure and hydraulic characteristics. The objectives of this work were to apply the pore network model to characterize pore structure from large images to quantify pore structure, calculate water retention and hydraulic conductivity properties from a three dimensional soil image, and to combine measured hydraulic properties from experiments with calculated hydraulic properties from image. Soil samples were taken from a site located at the Baltimore science center, which is located inside of the city. Undisturbed columns were taken from the site and scanned with a computer tomographer at resolutions of 22 ${\mu}m$. Pore networks were extracted by medial-axis transformation and were used to measure pore geometry from one of the scanned samples. Water retention and unsaturated hydraulic conductivity values were calculated from the soil image. Properties of soil bulk density, water retention and unsaturated hydraulic conductivity were measured from three replicates of scanned soil samples. 3D image analysis provided accurate detailed pore properties such as individual pore volumes, pore length, and tortuosity of all pores. These data made possible to calculate accurate estimations of water retention and hydraulic conductivity. Combination of the calculated and measured hydraulic properties gave more accurate information on pore sizes over wider range than measured or calculated data alone. We could conclude that the hydraulic property computed from soil images and laboratory measurements can describe a full structure of intra- and inter-aggregate pores in soil.

Study on Public Awareness of establishing Marine Protected Areas - Case Study of Guimaras Province, Philippines using Contingent Valuation Method (해양보호구역의 설정에 대한 대중인식도 연구 - 조건부 가치측정법을 이용한 필리핀 기마라스주의 사례)

  • Kim, Tae-Goun
    • Journal of Navigation and Port Research
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    • v.38 no.6
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    • pp.663-672
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    • 2014
  • In Korea and the Philippines, as well as all over the world, with the recognition of the importance of marine ecological resources, the marine protected areas(MPA) have been established and managed to protect and preserve these resources. While the number of marine protected areas for marine ecological resources protection has been increased, there is main problem that the most of MPAs do not achieve their intended management objectives. the effective management. Because of the positive and negative impacts on local communities and fishermen as direct stockholders, there has been ongoing debate on the pros and cons of implementing MPAs. Accordingly, this research conducted a case study of establishing Marine Protected Areas in Guimaras, Philippines because Philippines fisheries code of 1998 (Republic Act 8550), which is enacted to manage, conserve and protect fishery resources, obliged local governments to designate no less than 15% of jurisdictional municipal water as fisheries resource protection areas for a long time. To do this, a dichotomous-choice contingent-valuation survey was conducted in the two municipalities of Guimaras, Philippines to investigate public opinion in debates over MPAs and to estimate willingness to pay (WTP) for MPAs to protect and conserve marine habitats for fishery resources. Because of the expected economic costs by prohibiting fishing activities within the establishing newMPA, 58.7% of respondents thought the costs should be compensated, but 91.4% respondents voted in favor of increasing MPAs for fisheries resources as a protective measure. Finally, with Contingent Valuation Method(CVM), the aggregate mean WTP (375.5ha) of San Lorenzo and Sibunag residents in Guimaras Province, Philippines for establishing the additional MPA in their municipality waters was estimated to $1,046,791. Therefore, these findings could be used as a valuable data for establishing effective management plan of MPAs in Korea.

A Study on the Resource Recovery of Fe-Clinker generated in the Recycling Process of Electric Arc Furnace Dust (전기로 제강분진의 재활용과정에서 발생되는 Fe-Clinker의 자원화에 관한 연구)

  • Jae-hong Yoon;Chi-hyun Yoon;Hirofumi Sugimoto;Akio Honjo
    • Resources Recycling
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    • v.32 no.1
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    • pp.50-59
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    • 2023
  • The amount of dust generated during the dissolution of scrap in an electric arc furnace is approximately 1.5% of the scrap metal input, and it is primarily collected in a bag filter. Electric arc furnace dust primarily consists of zinc and ion. The processing of zinc starts with its conversion into pellet form by the addition of a carbon-based reducing agent(coke, anthracite) and limestone (C/S control). These pellets then undergo reduction, volatilization, and re-oxidation in rotary kiln or RHF reactor to recover crude zinc oxide (60%w/w). Next, iron is discharged from the electric arc furnace dust as a solid called Fe clinker (secondary by-product of the Fe-base). Several methods are then used to treat the Fe clinker, which vary depending on the country, including landfilling and recycling (e.g., subbase course material, aggregate for concrete, Fe-source for cement manufacturing). However, landfilling has several drawbacks, including environmental pollution due to leaching, high landfill costs, and wastage of iron resources. To improve Fe recovery in the clinker, we pulverized it into optimal -sized particles and employed specific gravity and magnetic force selection methods to isolate this metal. A carbon-based reducing agent and a binding material were added to the separated coarse powder (>10㎛) to prepare briquette clinker. A small amount (1-3%w/w) of the briquette clinker was charged with the scrap in an electric arc furnace to evaluate its feasibility as an additives (carbonaceous material, heat-generating material, and Fe source).

A Study on Industries's Leading at the Stock Market in Korea - Gradual Diffusion of Information and Cross-Asset Return Predictability- (산업의 주식시장 선행성에 관한 실증분석 - 자산간 수익률 예측 가능성 -)

  • Kim Jong-Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.355-380
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    • 2004
  • I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in

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