• Title/Summary/Keyword: Kappa distribution

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Applying Ensemble Model for Identifying Uncertainty in the Species Distribution Models (종분포모형의 불확실성 확인을 위한 앙상블모형 적용)

  • Kwon, Hyuk Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.4
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    • pp.47-52
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    • 2014
  • Species distribution models have been widely applied in order to assess biodiversity, design reserve, manage habitat and predict climate change. However, SDMs has been used restrictively to the public and policy sectors owing to model uncertainty. Recent studies on ensemble and consensus models have been increased to reduce model uncertainty. This paper was carried out single model and multi model for Corylopsis coreana and compares two models. First, model evaluation was used AUC, kappa and TSS. TSS was the most effective method because it was easy to compare several models and convert binary maps. Second, both single and ensemble model show good performance and RF, Maxent and GBM was evaluated higher, GAM and SRE was evaluated lower relatively. Third, ensemble model tended to overestimate over single model. This problem can be solved by the suitable model selection and weighting through collaboration between field experts and modeler. Finally, we should identify causes and magnitude of model uncertainty and improve data quality and model methods in order to apply special decision-making support system and conservation planning, and when we make policy decisions using SDMs, we should recognize uncertainty and risk.

The Analysis of Evergreen Tree Area Using UAV-based Vegetation Index (UAV 기반 식생지수를 활용한 상록수 분포면적 분석)

  • Lee, Geun-Sang
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.1
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    • pp.15-26
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    • 2017
  • The decrease of green space according to the urbanization has caused many environmental problems as the destruction of habitat, air pollution, heat island effect. With interest growing in natural view recently, proper management of evergreen tree which is lived even the winter season has been on the rise importantly. This study analyzed the distribution area of evergreen tree using vegetation index based on unmanned aerial vehicle (UAV). Firstly, RGB and NIR+RG camera were loaded in fixed-wing UAV and image mosaic was achieved using GCPs based on Pix4d SW. And normalized differences vegetation index (NDVI) and soil adjusted vegetation index (SAVI) was calculated by band math function from acquired ortho mosaic image. validation points were applied to evaluate accuracy of the distribution of evergreen tree for each range value and analysis showed that kappa coefficient marked the highest as 0.822 and 0.816 respectively in "NDVI > 0.5" and "SAVI > 0.7". The area of evergreen tree in "NDVI > 0.5" and "SAVI > 0.7" was $11,824m^2$ and $15,648m^2$ respectively, that was ratio of 4.8% and 6.3% compared to total area. It was judged that UAV could supply the latest and high resolution information to vegetation works as urban environment, air pollution, climate change, and heat island effect.

Variation of Seasonal Groundwater Recharge Analyzed Using Landsat-8 OLI Data and a CART Algorithm (CART알고리즘과 Landsat-8 위성영상 분석을 통한 계절별 지하수함양량 변화)

  • Park, Seunghyuk;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.31 no.3
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    • pp.395-432
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    • 2021
  • Groundwater recharge rates vary widely by location and with time. They are difficult to measure directly and are thus often estimated using simulations. This study employed frequency and regression analysis and a classification and regression tree (CART) algorithm in a machine learning method to estimate groundwater recharge. CART algorithms are considered for the distribution of precipitation by subbasin (PCP), geomorphological data, indices of the relationship between vegetation and landuse, and soil type. The considered geomorphological data were digital elevaion model (DEM), surface slope (SLOP), surface aspect (ASPT), and indices were the perpendicular vegetation index (PVI), normalized difference vegetation index (NDVI), normalized difference tillage index (NDTI), normalized difference residue index (NDRI). The spatio-temperal distribution of groundwater recharge in the SWAT-MOD-FLOW program, was classified as group 4, run in R, sampled for random and a model trained its groundwater recharge was predicted by CART condidering modified PVI, NDVI, NDTI, NDRI, PCP, and geomorphological data. To assess inter-rater reliability for group 4 groundwater recharge, the Kappa coefficient and overall accuracy and confusion matrix using K-fold cross-validation were calculated. The model obtained a Kappa coefficient of 0.3-0.6 and an overall accuracy of 0.5-0.7, indicating that the proposed model for estimating groundwater recharge with respect to soil type and vegetation cover is quite reliable.

Yangkyuksanhwa-tang effected to Atopic Dermatitis (양격산화탕(凉膈散火湯)이 Atopy 피부염(皮膚炎)에 미치는 영향(影響))

  • Yun, Bo-Hyun;Park, Seong-Sik
    • Journal of Sasang Constitutional Medicine
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    • v.16 no.2
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    • pp.84-98
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    • 2004
  • 1. Objectives Yangkyuksanhwa-tang is used mush in pruritus and dermatopathy of Soyangin. It is suggested this prescription is effective on atopy dermatitis. 2. Methods For observation of Yangkyuksanhwa-tang effected to atopic dermatitis, extract of Yangkyuksanhwa-tang has been dispensed to the stratum corneum of epithelium in dermatome of murine after making damage to its defense mechanism against fat and causing atopic dermatitis artificially. After that, the change in outer dermatome and minute mechanism of epidermis, the change of eosinophil, the change in distribution of soybean agglutinin, the change in distribution of fat and ceramide in stratum corneum, the change in inflammation in dermatome, the change of cell accrementition and apoptosis, and the effect on anaphylaxis and Staphylococcus aureus was observed. 3. Results After administration of Yangkyuksanhwa-tang, severe skin damage such as eczema and psoriasis, that was observed in the case of atopy dermatitis, was decreased and the increase of eosinophil in serum was suppressed. Lipid lamella was recovered, so epidermal demage was relieved. The distribution of HSP70 in the outer skin was decreased. Yangkyuksanhwa-tang suppressed activation of $NF-_{\kappa}B$ p50, induced CD11/18b not to be generated, and suppressed inflammatory response of skin. Anaphylaxis and groth of Staphylococcus aureus was suppressed. 4. Conclusions Yangkyuksanhwa-tang decreased skin damage of atopy dermatitis. It has antibiosis about Staphylococcus aureus, it can be medicinal substances on atopy dermatitis. In addition, it is possible that it can be medicinal substances on regional skin allergy.

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A Growth and Yield Model for Predicting Both Forest Stumpage and Mill Side Manufactured Product Yields and Economics

  • Schultz Emily B.;Matney Thomas G.
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.305-309
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    • 2006
  • This paper presents and illustrates the application of a growth and yield model that supports both forest and mill side volume and value estimates. Traditional forest stand growth and yield models represent the forest landowner view of yield and economics. Predicted yields are estimates of what one would expect from a procurement cruise, and current stumpage prices are applied to investigate optimum management strategies. Optimum management regimes and rotation ages obtained from the forest side view are unlikely to be economically optimal when viewed from the mill side. The actual distribution of recoverable manufactured product and its value are highly dependent on mill technologies and configurations. Overcoming this limitation of growth and yield computer models necessitates the ability to predict and price the expected manufactured distribution of lumber, lineal meters of veneer, and tonnes of air dried pulp fiber yield. With these embedded models, users of the yield simulator can evaluate the economics of possible/feasible management regimes from both the forest and mill business sides. The simulator is a forest side model that has been modified to produce estimates of manufactured product yields by embedding models for 1) pulpwood chip size class distribution and pulp yield for any kappa number (Schultz and Matney, 2002), 2) a lumber yield and pricing model based on the Best Opening Face model developed by the USDA Forest Service Forest Products Laboratory (Lewis, 1985a and Lewis, 1985b), and 3) a lineal meter veneer model derived from peeler block tests. While the model is strictly applicable to planted loblolly pine (Pinus taeda L.) on cutover site-prepared land in the United States (US) Gulf South, the model and computer program are adaptable to any region and forest type.

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A Software Reliability Cost Model Based on the Shape Parameter of Lomax Distribution (Lomax 분포의 형상모수에 근거한 소프트웨어 신뢰성 비용모형에 관한 연구)

  • Yang, Tae-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.2
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    • pp.171-177
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    • 2016
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this study, reliability software cost model considering shape parameter based on life distribution from the process of software product testing was studied. The cost comparison problem of the Lomax distribution reliability growth model that is widely used in the field of reliability presented. The software failure model was used the infinite failure non-homogeneous Poisson process model. The parameters estimation using maximum likelihood estimation was conducted. For analysis of software cost model considering shape parameter. In the process of change and large software fix this situation can scarcely avoid the occurrence of defects is reality. The conditions that meet the reliability requirements and to minimize the total cost of the optimal release time. Studies comparing emissions when analyzing the problem to help kurtosis So why Kappa efficient distribution, exponential distribution, etc. updated in terms of the case is considered as also worthwhile. In this research, software developers to identify software development cost some extent be able to help is considered.

Effect of Flue Gas Heat Recovery on Plume Formation and Dispersion

  • Wu, Shi Chang;Jo, Young Min;Park, Young Koo
    • Particle and aerosol research
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    • v.8 no.4
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    • pp.161-172
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    • 2012
  • Three-dimensional numerical simulation using a computational fluid dynamics (CFD) was carried out in order to investigate the formation and dispersion of the plume discharged from the stack of a thermal power station. The simulation was based on the standard ${\kappa}{\sim}{\varepsilon}$ turbulence model and a finite-volume method. Warm and moist exhaust from a power plant stack forms a visible plume as entering the cold ambient air. In the simulation, moisture content, emission velocity and temperature of the flue gas, air temperature and wind speed were dealt with the main parameters to analyze the properties of the plume composed mainly of water vapor. As a result of the simulation, the plume could be more apparent in cold winter due to a big difference of latent heat capacity. At no wind condition, the white plume rises 120 m upward from the top of the stack, and expands to 40 m around from the stack in cold winter after flue gas heat recovery. The influencing distance of relative humidity will be about 100 m to 400 m downstream from the stack with a cross wind effect. The decrease of flue gas temperature by heat recovery of thermal energy facilitates the formation of the plume and restrains its dispersion. Wind speed with vertical distribution affects the plume dispersion as well as the density.

An Analytical Study on the Condensation of Submerged Vapor Jets in Subcooled Liquids (과냉수에서의 증기응축제트에 대한 해석적 연구)

  • 김기웅;이계복;김환열
    • Journal of Energy Engineering
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    • v.8 no.2
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    • pp.333-340
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    • 1999
  • A numerical study of turbulent condensing vapor jet submerged in subcooled liquids has been conducted. A physical model of the process is presented employing the locally homogeneous flow approximation of two phase flow in conjunction with a $\kappa$-$\varepsilon$-g model of turbulence properties. In this model the turbulence is represented by differential equations for its kinetic energy and dissipation. A differential equation for the concentration fluctuations is solved and a clipped normal probability distribution function is proposed for the mixture fraction. Effects of steam mass flux, pool temperature and nozzle internal diameter on the condensing vapor jet are also analyzed. The model is evaluated using existing data for turbulent condensing vapor jets. The agreement between the predictions and the available experimental data is good.

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Temporal and spatial variation in the distribution of life history phases of Chondrus crispus (Gigartinales, Rhodophyta)

  • Garbary, David J.;Tompkins, Elizabeth;White, Katelyn;Corey, Peter;Kim, Jang-K.
    • ALGAE
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    • v.26 no.1
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    • pp.61-71
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    • 2011
  • Thirty populations of Chondrus crispus Stackhouse from Nova Scotia were collected during the years 1993 to 2011. Taken from estuaries, wave exposed open coasts, high intertidal rock pools and shallow subtidal habitats, the populations were evaluated for relative abundance of tetrasporophytic and gametophytic life history phases. Over 2,800 thalli were characterized using the resorcinol-acetal test to distinguish the kappa- and lambda-carrageenan containing fronds of gametophytes and tetrasporophytes, respectively. These populations had $77{\pm}5%$ gametophytes (mean ${\pm}95%$ confidence interval), with most populations having gametophyte : sporophyte ratios ranging from 2 : 1 to 9 : 1. No population had a dominance of tetrasporophytes, although two populations had 1 : 1 ratios. A meta-analysis of our data along with previously published accounts showed no significant changes in gametophyte dominance with respect to hypothesized gradients of wave exposure, salinity, or water depth. Significant changes occurred in ratios at five sites where replicate sampling occurred in different years. We conclude that C. crispus in Maritime Canada has a natural ratio of 3 : 1 or greater in stable conditions, and that lower ratios represent recovery from disturbance in which bare substratum is created that is subsequently colonized by carpospores from remaining gametophytic thalli.

The Applicability Analysis of FDS code for Fire-Driven Flow Simulation in Railway Tunnel (철도터널 화재 유동에 사용되는 FDS code의 적용성 분석)

  • Jang, Yong-Jun;Park, Won-Hee
    • Journal of the Korean Society for Railway
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    • v.10 no.2 s.39
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    • pp.224-230
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    • 2007
  • The performance and applicability of FDS code is analyzed for flow simulation in railway tunnel. FDS has been built in NIST(USA) for simulation of fire-driven flow. RANS and DNS's results are compared with FDS's. AJL non-linear ${\kappa}-{\epsilon}$[7,8] model is employed to calculate the turbulent flow for RANS. DNS data by Moser et al.[9] are used to prove the FDS's applicability in the near wall region. Parallel plate is used for simplified model of railway tunnel. Geometrical variables are non-dimensionalized by the height (H) of parallel plate. The length of streamwise direction is 50H and the length of spanwise direction is 5H. Selected Re numbers are 10,667 for turbulent flow and 133 for laminar low. The characteristics of turbulent boundary layer are introduced. AJL model's predictions of turbulent boundary layer are well agreed with DNS data. However, the near wall turbulent boundary layer is not well resolved by FDS code. Slip conditions are imposed on the wall but wall functions based on log-law are not employed by FDS. The heavily dense grid distribution in the near wall region is necessary to get correct flow behavior in this region for FDS.