• Title/Summary/Keyword: density index

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Land Use and Greenspace Structure in Several Cities of Kangwon Province (강원도 일부 도시들의 토지이용 및 녹지구조)

  • 조현길;이기의;윤영활;서옥하
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.4
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    • pp.171-183
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    • 1998
  • The purpose of this study was to analyze urban greenspace area and vegetation structure by land use types for both Chuncheon and Kangleung. Natural and agricultural lands were predominant in the study cites, as 75-80% of total area. Residential lands accounted for about 10%, and commercial and industrial lands(including transportation), 5-10%. Only 10-20% of urban residential and commercial area was covered with greenspace. Woody plant cover was 12-13%, and tree density was 1.5 trees/100$m^2$ for urban lands(all land use types except natural land) in both cities. The tree-age structure was largely characterized by young, growing tree population, and species diversity within a diameter class decreases as the diameter classes get larger. Urban lands of both cities had quite a similar species composition of woody plants (similarity index of 0.65). Street trees in Chuncheon were intensively pruned annually to protect the above ground utility lines. Some strategies were explored to solve problems found in the existing greenspace structures. They included increase of biomass and greenspace area through minimization of unnecessary impervious surfaces, creation of multilayered and multiaged vegetation structures, relocation of above ground utility lines and avoidance of intensive tree pruning, and establishment of greenspace proximity and connectivity.

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OBSERV ATION OF MICRO-STRUCTURE AND OPTICAL PROPERTISE OF TITANIUM DIOXIDE THIN FILMS USING OPTICAL MMEHODS

  • Kim, S.Y.;Kim, H.J.
    • Journal of Surface Science and Engineering
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    • v.29 no.6
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    • pp.788-796
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    • 1996
  • $TiO_2$ films prepared by RF magnetron sputtering, electron beam evaporation, ion assisted deposition (IAD) and sol-gel method are prepared on c-Si substrate and vitreous silica substrate respectively. From the transmission spectra of $TiO_2$ films on vitreous silica substrate in the spectral region from 190 nm to 900 nm, k($\lambda$) of $TiO_2$ is obtained. Using k($\lambda$) in the interband transition region the coefficients of the quantum mechanical dispersion relation of an amorphous $TiO_2$ and hence n($\lambda$) including the optically opaque region of above fundamental transition energy are obtained. The spectroscopic ellipsometry spectra of $TiO_2$ films in the spectral region of 1.5-5.0eV are model analyzed to get the film packing density variation versus i) substrate material, ii) film thickness and iii) film growth technique. The complex refractive index change of these $TiO_2$ films versus water condensation is also studied. Film micro-structures by SE modelling results are compared with those by atomic force microscopy images and X-ray diffraction data.

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Anti-hyperlipidemia and Anti-arteriosclerosis Effects of Laminaria japonica in Sprague-Dawley Rats

  • Lee, Seung-Joo;Kim, Chong-Wook;Jang, Hyuk-Jai;Cho, Soon-Yeong;Choi, Jong-Won
    • Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.235-241
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    • 2011
  • The anti-hyperlipidemic effects of dietary supplementation with sea tangle Laminaria japonica were investigated using an animal model in which normal rats were fed either sea tangle, sea tangle ethanol extract (EE-ST) and sea tangle extracted residue (ER-ST). Total lipid and triglyceride levels in the serum were significantly (P < 0.05) reduced in rats fed ER-ST at a dose of 200 mg/kg body weight when compared to hyperlipidemic control rats. Significant decreases in serum total cholesterol and low density lipoprotein-cholesterol levels also occurred in rats fed ER-ST at 200 mg/kg body weight. In addition, the atherosclerosis index and superoxide dismutase in blood lipids were significantly (P < 0.05) lowered in rats fed ER-ST at 200 mg/kg body weight as compared to control rats. In conclusion, sea tangle and ER-ST exhibited beneficial anti-hyperlipidemic and anti-arteriosclerosis effects.

Aluminum Inhibits Vitellogenin Production via Toxic Effects on Hepatocytes in the Rockfish Sebastes schlegelii

  • Hwang, Un-Ki;Kang, Han-Seung;Lee, Yoon;Shon, Jae-Kyoung
    • Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.355-361
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    • 2011
  • Effects of aluminum (Al) on plasma vitellogenin (VTG), alkaline-labile phosphorus (ALPP), calcium (Ca), glutamate pyruvate transaminase (GPT), the hepatosomatic index (HSI), and hepatic Al concentration were examined in estradiol-$17{\beta}$ ($E_2$)-administered immature rockfish Sebastes schlegeli. Fish were injected intraperitoneally with $E_2$ (5 mg/kg body weight [BW]) and/or Al (0, 0.1, 1, 5, and 10 mg/kg BW) and plasma and liver samples were extracted 7 days later. After sodium dodecyl sulfate polyacrylamide gel electrophoresis, the relative amount of VTG was determined by integrated optical density. VTG accounted for 23.6% of the total proteins in the control group, but this value decreased with increasing Al administration. Al reduced the concentrations of ALPP and Ca in a concentration-dependent manner and significant reduction occurred at Al concentrations greater than 5 mg/kg. The concentration of GPT increased in a concentration-dependent manner in all Al-administered rockfish. The concentrations of Al in the liver also increased, and HSI was decreased, in a concentration-dependent manner. These results suggest that Al inhibits $E_2$-induced VTG production by being toxic to hepatocytes in marine fish.

On Study of Pulse Wave Signal According to Postural Change Using Finger Plethysmography (손가락 끝 용적맥파를 이용한 자세변화에 따른 맥파 신호에 관한 연구)

  • Choi, B.C.;Kim, C.H.;Jung, D.K.;Suh, D.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.125-126
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    • 1998
  • Pulse conduction velocity is determined by areterial compliance, which is changed by lateral pressure of arterial wall. Hydrostatic pressure of the limb vessel is changed by body position, especially in elevated arm. The arterial pulse in the finger causes the blood volume to change, changing the optical density of the blood. Photoplethysmograph of index finger was obtained by LED and phototransistor. Pulse transmission time(PTT) was measured by the interval between the peak of ECG R wave and the peak of the finger plethysmogram. PTT was increased by upward position of arm, and decreased by downward position of the arm compared to horizontal position. This result suggests that relationship between finger plethysmography and postural change could be applied to evaluate clinical cardiovascular status.

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Performance Analysis of Economic VaR Estimation using Risk Neutral Probability Distributions

  • Heo, Se-Jeong;Yeo, Sung-Chil;Kang, Tae-Hun
    • The Korean Journal of Applied Statistics
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    • v.25 no.5
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    • pp.757-773
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    • 2012
  • Traditional value at risk(S-VaR) has a difficulity in predicting the future risk of financial asset prices since S-VaR is a backward looking measure based on the historical data of the underlying asset prices. In order to resolve the deficiency of S-VaR, an economic value at risk(E-VaR) using the risk neutral probability distributions is suggested since E-VaR is a forward looking measure based on the option price data. In this study E-VaR is estimated by assuming the generalized gamma distribution(GGD) as risk neutral density function which is implied in the option. The estimated E-VaR with GGD was compared with E-VaR estimates under the Black-Scholes model, two-lognormal mixture distribution, generalized extreme value distribution and S-VaR estimates under the normal distribution and GARCH(1, 1) model, respectively. The option market data of the KOSPI 200 index are used in order to compare the performances of the above VaR estimates. The results of the empirical analysis show that GGD seems to have a tendency to estimate VaR conservatively; however, GGD is superior to other models in the overall sense.

Enhancement of Mixing Performance in Viscous Liquid Using an Electromagnetically Driven Microrobot (초소형 로봇을 이용한 점도성 유체의 혼합 효율 향상)

  • Song, Hyeonseok;Park, Yuna;Chung, Sang Kug
    • Journal of the Korean Society of Visualization
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    • v.16 no.2
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    • pp.53-58
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    • 2018
  • This paper presents an electromagnetically driven microrobot for the enhancement of mixing performance in high viscous liquid media such as blood and bone marrow. First, an electromagnetic system was fabricated, and the magnetic flux density generated from the system was compared with the theoretical value. Second, the reciprocating motion of the microrobot was demonstrated in microchannel using electromagnetic system. As a proof of concept, the mixing performance by the electromagnetically driven microrobot in high viscous liquid was investigated using safranin solution. As a result, it was completely mixed within 140 s with the reciprocating motion of the microrobot while it took 1680 s for natural diffusion. In addition, the mixing efficiency was quantitatively evaluated through a mixing index obtained by an image analysis. The proposed method provides not only wireless actuation of a microrobot with a simple design but also high mixing performance in variety of high viscous liquid media.

The Study on Portland Cement Stabilization on the Weathered Granite Soils (on the Durability) (화강암질 풍화토의 시멘트에 의한 안정처리에 관한 연구 (내구성을 중심으로))

  • 도덕현
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.22 no.3
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    • pp.60-74
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    • 1980
  • Soil-cement mixtures involve problems in it's durability in grain size distribution and mineral composition of the used soils as well as in cement content, compaction energy, molding water content, and curing. As an attempt to solve the problems associated with durability of weathered granite soil with cement treated was investigated by conducting tests such as unconfined compression test, it's moisture, immers, wet-dry and freeze-thaw curing, mesurement of loss of weight with wet-dry and freeze-thaw by KS F criteria and CBR test with moisture curing on the five soil samples different in weathering and mineral composition. The experimental results are summarized as follows; The unconfined compressive strength was higher in moisture curing rather than in the immers and wet-dry, while it was lowest in freeze-thaw. Decreasing ratio of unconfined compressive strength in soil-cement mixtures were lowest in optimum moisture content or in the dry side rather than optimum moisture content with freeze-thaw. The highly significant ceofficient was obtained between the cement content and loss of weight with freeze-thaw and wet-dry. It was possible to obtain the durability of soil-cement mixtures, as the materials of base for roads, containing above 4 % of cement content, above 3Okg/cm$_2$ of unconfined compressive trength with seven days moisture curing or 12 cycle of freeze-thaw after it, above 100% of relative unconfined compressive strength, 80% of index of resistance, below 14% of loss of weight with 12 cycle of wet-dry and above 1. 80g/cm$_2$ of dry density.

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A Study on the Strength Characteristics of Lime-Soil Mixtures. (석회혼합토의 강도특성에 관한 연구)

  • 조성정
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.22 no.3
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    • pp.46-59
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    • 1980
  • This study was conducted to obtain the most effective distribution of grain size and the optimum lime content for lime-soil stabilization. To achieve the aim, the change of consistency, the characteristics of compaction and unconfined compressive strength were tested by adding of 0, 4, 6, 8, 10 and 12 percent lime by weight for all soils adjusted by given ratios of sand to clay. The results obtained were as follows; 1. There was a tendency that the plasticity index of lime-soil mixture was decreased by increasing the amount of lime, whereas the liquid limit was varied irregularly and the plastic limit was increased. 2. With the addition of more lime, the optimum moisture content of lime-soil mixture was increased, and the maximum dry density was decreased. 3. The optimum lime content of lime-soil mixture was varied from soil to soil, and the less amount of small grain size, the less value of optimum lime content. 4. The optimum distribution of grain size for lime-soil mixture was in the soil, having the ratio of about 60 percent of cohesive clay and about 40 percent of sand by weight. 5. In the soil having fine grain size, the effect of curing appeared for long periods of time, whereas the increasing rate of unconfined compressive strength was great on the soil of coarse grain size in the earlier stage of curing period.

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Studies on the Inheritance of Resistance to Bacterial Wilt(Ralstonia solanacearum) in Tobacco(Nicotiana tabacum L.) (연초의 세균성마름병 저항성 유전에 관한 연구)

  • 정석훈
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.1
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    • pp.25-30
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    • 2000
  • Bacterial wilt(Ralstonia solanacearum) is one of the major diseases of flue-cured tobacco (Nicotiana tabacum L.) in the world. This study was conducted to investigate degree of dominance, selection, and correlation between leaf shape and degree of bacterial wilt resistance in flue-cured tobacco. The degree of disease caused by bacterial wilt was evaluated in parents, F$_1$, F$_2$ and F$_3$ populations of two crosses, BY 4 x NC 95 and BY 4 x Coker 86, in the infected field. The leaf shape index was also measured in parents and F$_2$ population of BY 4 x NC 95. The incidence of bacterial wilt was observed in the middle of June and peaked in late July, when the highest value of pathogen density reached 1.0 x 10$^{6}$ colony forming unit per gram. It was concluded that the inheritance mode of risestance to bacterial wilt in the above two crosses of susceptible and resistant varieties was recessive and polygenic. The resistance to bacterial wilt was significantly correlated with leaf shape in F2 generation of BY 4 x NC 95. But certain plants having narrower leaves were also resistant to bacterial wilt. It is considered that the bacterial wilt resistant lines having narrower leaves could be selected. The selection for bacterial wilt resistance in the F$_2$ population might be effective.

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