• 제목/요약/키워드: Agriculture model

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COMPREHENSIVE ASSESSMENT MODEL OF ECOLOGICAL RIPARIAN ZONE

  • Xia, Ji-Hong;Wu, Wei;Yan, Zhong-Min
    • Water Engineering Research
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    • 제6권4호
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    • pp.169-178
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    • 2005
  • Comprehensive assessment of ecological riparian zone is to analyze and evaluate the status of riparian zone ecosystem. The existing problem of the ecosystem can be found through the assessment. The AHP-FUZZY method used in the assessment is based on the hierarchy model of index, grade model of object, and attribution degree of index. Accordingly, the four models have been discussed and presented from the aspect of the stability, landscape, eco-health and eco-safety of riparian zone.

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아산시 친환경 지역농업의 자원순환시스템 구축방향 (Establishments of the System of Regional Resource Circulation based on Environmental-Friendly Agriculture at Asan Area)

  • 윤종열;김호
    • 한국유기농업학회지
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    • 제13권1호
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    • pp.1-22
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    • 2005
  • This study was focused on the system of regional resource circulation(RRC) of Asan-Si as a case region. So 301 farmers(members of producer organization) who are managing environmental-friendly agriculture (EFA) are surveyed. The RRC system is focused on establishing the system of regional complex farming connected with the seedling fanning and the livestock. The main results surveyed are as follows : First, total cultivated acreage is 574ha. Second, the total quantity of by-products of rices, beans, wheats is 983M/T. Third, the total quantity of nutrient requirement for seeding fanning is 85,335.6kg This research shows how to develop the RRC system for EFA. The development model and strategies are as follows : The first model for the system of regional resource circulation can be called the scenario of the best output for the system of environmentally friendly resource circulation. It is considered to estimate the appropriate number of heads of Korean cattle and hen which can be bred simultaneously. And the second model can be called the scenario of the regional allotment for the appropriate number of heads of those. It is considered to estimate the appropriate number of heads of those which can be alloted by the individual farm or area.

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농업·농촌의 공익적 가치에 대한 경제적 평가 (The Economic Evaluation of the Public Values of Agriculture and Rural Area in Korea)

  • 김용렬;정학균;허주녕
    • 농촌계획
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    • 제20권4호
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    • pp.101-112
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    • 2014
  • The public value of agriculture and rural areas is closely associated with the concept of multifunctionality of agriculture and rural areas, which in turn signifies economic values other than the production function of agriculture and rural areas. Based on the survey results, virtual scenarios were set up and the contingent valuation method (CVM) was used to estimate the amount consumers are willing to pay (WTP) for the public functions of agriculture and rural areas. This study selected five domains of the public value (environment conservation, maintenance of landscape and cultural tradition, enhancement of national prestige, local community maintenance and socio-economic functions, and food security) and 21 value items as components of the public value. An economic assessment of the public value of agriculture and rural areas was conducted using a binomial logistic regression model. The estimation results showed that the public value consumers are willing to pay ranges from a minimum of 6,346.8 billion won to a maximum of 9,327.2 billion won.

Seasonal Grouping in Year-Season Animal Model Evaluation of Sahiwal Cattle

  • Khan, M.S.;Ali, A.;Ali, S.;Saleem, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제10권1호
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    • pp.75-78
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    • 1997
  • Season is very important as it defines the contemporaries for sire and cow evaluation. An attempt is made for defining season for animal model evaluation of Sahiwal animals, using 1,227 records from 730 cows. Cows were required to have a lactation length of 305-days. Ten different combinations of months for two, four, five or other seasons were tried. The other fixed effect in the model was age defined within parity. The random effects were permanent environment and animal's breeeding value along with the residual effects. A single trait animal model was used where all known relationships of an animal were incorporated in a relationship matrix. The error variance from the fitted model decreased as the number of year-season combinations increased, indicating a month-year model to be more appropriate. This, on the other hand, decreased the number of contemporaries for certain subclasses to a minimum of one, making the bull comparisons invalid. Use of a two season scenario, with winter (November through February) and summer (March through October) was better than the other combinations in terms of error variance of the fitted model and the number of lactations represented in any year-season subclass.

The Role of the Spatial Externalities of Irrigation on the Ricardian Model of Climate Change: Application to the Southwestern U.S. Counties

  • Bae, Jinwon;Dall'erba, Sandy
    • Asian Journal of Innovation and Policy
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    • 제10권2호
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    • pp.212-235
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    • 2021
  • In spite of the increasing popularity of the Ricardian model for the study of the impact of climate change on agriculture, there has been few attempts to examine the role of interregional spillovers in this framework and all of them rely on geographical proximity-based weighting schemes. We remedy to this gap by focusing on the spatial externalities of surface water flow used for irrigation purposes and demonstrate that farmland value, the usual dependent variable used in the Ricardian framework, is a function of the climate variables experienced locally and in the upstream locations. This novel approach is tested empirically on a spatial panel model estimated across the counties of the Southwest USA over 1997-2012. This region is one of the driest in the country, hence its agriculture relies heavily on irrigated surface water. The results highlight how the weather conditions in upstream counties significantly affect downstream agriculture, thus the actual impact of climate change on agriculture and subsequent adaptation policies cannot overlook the streamflow network anymore.

Development and evaluation of a model for management of plant pests in organic cucumber cultivation

  • Ko, S.J.;Kang, B.R.;Kim, D.I.;Choi, D.S.;Kim, S.G.;Kim, H.K.;Kim, H.J.;Choi, K.J.;Kim, Y.C.
    • 한국유기농업학회지
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    • 제19권spc호
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    • pp.263-266
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    • 2011
  • Crop protection strategies in organic horticulture aim to prevent insect pest and plant disease problems through utilization of non-chemical based control means. In order to develop a model for management of plant diseases and insects in organic cucumber cultivation, we compared efficacies between chemical pesticide spraying system and biological control means in semi-forcing and retarding cucumber cultivation during 2005 and 2006. Conventional chemical spray program using various chemical pesticides was applied 5 - 10 days intervals, while two different non-chemical pesticide application programs using two formulated biopesticides Topseed$^{TM}$ and Q-fect$^{TM}$, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 1) and using egg-yolk and cooking oil(EYCO), Bordeaux mixture, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 2) were applied 5 - 7 days intervals during entire cucumber cultivation period. Efficacy of both biocontrol agents programs was effective to comparable to conventional chemical pesitice spray program to control plant diseases such as powdery mildew and downy mildew as well as insect pests such as aphids and thrips which are known as major threats in cucumber organic cultivation. In this study, we established and evaluated an effective and economic crop protection strategy using various biological resources can be used to control plant diseases and pests simultaneously in organic cucumber cultivation field.

Sire-maternal Grandsire Model and Sire Model in Estimation of Genetic Parameters for Average Daily Gain and Carcass Traits of Japanese Black Cattle

  • Kim, Jong-Bok;Lee, Chaeyoung;Tsuyuki, Tsutomu;Shimogiri, Takeshi;Okamoto, Shin;Maeda, Yoshizane
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권12호
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    • pp.1678-1684
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    • 2006
  • The objectives of this study were to estimate genetic parameters and sire breeding values for average daily gain (ADG) and carcass traits using sire-maternal grandsire model with REML approach, sire model with REML approach, sire model without relationships among sires and with REML and ANOVA approach, and to investigate advantages and disadvantages of these methods. Data were collected from 42,325 Japanese Black steers and heifers finished and slaughtered from 1991 to 2004. Traits analyzed in this study were average daily gain (ADG) during the fattening period, live weight at slaughter (LW), cold carcass weight (CW), estimated lean yield percentage (LYE), longissimus muscle area (LMA), subcutaneous fat thickness (SFT), rib thickness (RT), and marbling score (BMS). Bivariate analyses were also performed to obtain genetic and phenotypic correlation coefficients among traits. Estimated breeding values were obtained from each model, and simple and rank correlations among breeding values from each model were calculated. Estimates of heritability using the four models ranged from 0.25 to 0.31 in ADG, from 0.21 to 0.24 in LW, from 0.23 to 0.27 in CW, from 0.10 to 0.17 in DP, from 0.40 to 0.42 in LYE, from 0.19 to 0.31 in LMA, from 0.31 to 0.34 in SFT, from 0.26 to 0.33 in RT, and from 0.18 to 0.44 in BMS. The differences in heritability estimates using the four models seemed to be feasible in ADG, CW, DP, LMA, RT, and BMS. Genetic correlation coefficients of ADG with CW, SFT, RT and BMS were moderate to high and positive while the genetic correlation coefficients between ADG and LYE was low and negative. Correlation coefficients of BMS with SFT were negligible for both genetic and phenotypic correlations. The correlations of estimates evaluated from sire models with those from sire-maternal grandsire model were not large enough to convincing that breeding values using a sire model were corresponding to those using a sire-maternal grand sire model. If information of maternal grand sires are not available, the sire model with incomplete pedigree information included only sire of sire (Model 2) is optimal among the sire models evaluated in this study.

Genetic Parameters for Litter Size in Pigs Using a Random Regression Model

  • Lukovic, Z.;Uremovic, M.;Konjacic, M.;Uremovic, Z.;Vincek, D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권2호
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    • pp.160-165
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    • 2007
  • Dispersion parameters for the number of piglets born alive were estimated using a repeatability and random regression model. Six sow breeds/lines were included in the analysis: Swedish Landrace, Large White and both crossbred lines between them, German Landrace and their cross with Large White. Fixed part of the model included sow genotype, mating season as month-year interaction, parity and weaning to conception interval as class effects. The age at farrowing was modelled as a quadratic regression nested within parity. The previous lactation length was fitted as a linear regression. Random regressions for parity on Legendre polynomials were included for direct additive genetic, permanent environmental, and common litter environmental effects. Orthogonal Legendre polynomials from the linear to the cubic power were fitted. In the repeatability model estimate of heritability was 0.07, permanent environmental effect as ratio was 0.04, and common litter environmental effect as ratio was 0.01. Estimates of genetic parameters with the random regression model were generally higher than in the repeatability model, except for the common litter environmental effect. Estimates of heritability ranged from 0.06 to 0.10. Permanent environmental effect as a ratio increased along a trajectory from 0.03 to 0.11. Magnitudes of common litter effect were small (around 0.01). The eigenvalues of covariance functions showed that between 7 and 8 % of genetic variability was explained by individual genetic curves of sows. This proportion was mainly covered by linear and quadratic coefficients. Results suggest that the random regression model could be used for genetic analysis of litter size.

A Study on Mathematical Model of Caprine Arthritis Encephalitis (CAE) and Development of Animal Quarantine Information System Adapted for Small Island

  • Hirata, Teppei;Yonahara, Yoshihito;Asharif, Faramarz;Omatsu, Tsutomu;Miyagi, Takeshi;Nagata, Yasunori;Mizutani, Tetsuya;Tamaki, Shiro
    • IEIE Transactions on Smart Processing and Computing
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    • 제2권5호
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    • pp.302-309
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    • 2013
  • This paper proposes a mathematical model of Caprine arthritis encephalitis (CAE), which is a disease causing significant economic damage to the goat farming industry, and reports the application of this model to the development of an information management system of animal quarantine to overcome this disease. The mathematical model of CAE was derived from the AIDs model in human case because epidemical characteristics of these diseases including infection pass are similar. This model can be expressed by simultaneous differential equations. Simulations using a new model were performed according Euler's and Runge-Kutta method using numerical analysis software. In each method, strong convergence was observed and the results were similar. The design of an information management system of animal quarantine was proposed as an application of the new model. System design was constructed on the assumption that in subtropical islands, the expected development of information infrastructure and utilization will become valuable in the future.

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