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 共查询到20条相似文献，搜索用时 31 毫秒
1.
This article applied the self-similarity of fractal theory to the soybean leaf with the aid of powerful iterative computation ability of computer,analyzed the generation principle of IFS code in the iterated function system,calculated the IFS code of the simulation soybean leaf.It basically realized the visualization simulation of soybean leaf and laid a foundation for the visualization simulation of the whole soybean plant.  相似文献   

2.
Owing to overcoming the characteristics that there are many economic and technical indexes which are fuzzy and incompatibility to each other in evaluating investment project,a new method is proposed. The method is based on the matter-element analysis and combined with the concepts of fuzzy mathematics, which is called the method of fuzzy matter-element analysis. It constructs the compound fuzzy matter element with the investment projects ,evaluation factors and their fuzzy value. Through establishing the best subjection degree (fuzzy value).complex fuzzy matter element of relational coefficient and weight aggregation of fuzzy matter-element model ,the writer achieves on optimum order of the investment projects according to the calculated relational degree and finds the best project. In this paper ,the calculation of weight adopts the analytical hierarchy process method (AHP). Through the actual example ,it shows that the model is simple and its calculation is reliable. It is very significant for the engineering evaluated bid and investment decision.  相似文献   

3.
Study on visualization simulation soybean leaf based on growth equation   总被引：1，自引：0，他引：1  
According to the virtual crops model research's need,the paper emphasized on the modeling theory and dynamic modeling methods,and took the soybean leaf as the example,introduced the establishment of leaf growth model based on growth equation,finally realized the visualization result based on OpenGL in VC platform.The paper has great significance on establishing the whole growth model and researching the crops growth principles.  相似文献   

4.
This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root’s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c++ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.  相似文献   

5.
The accurate representation of surface characteristic is an important process to simulate surface energy and water flux in land-atmosphere boundary layer. Coupling crop growth model in land surface model is an important method to accurately express the surface characteristics and biophysical processes in farmland. However, the previous work mainly focused on crops in single cropping system, less work was done in multiple cropping systems. This article described how to modify the sub-model in the SiBcrop to realize the accuracy simulation of leaf area index(LAI), latent heat flux(LHF) and sensible heat flux(SHF) of winter wheat growing in double cropping system in the North China Plain(NCP). The seeding date of winter wheat was firstly reset according to the actual growing environment in the NCP. The phenophases, LAI and heat fluxes in 2004–2006 at Yucheng Station, Shandong Province, China were used to calibrate the model. The validations of LHF and SHF were based on the measurements at Yucheng Station in 2007–2010 and at Guantao Station, Hebei Province, China in 2009–2010. The results showed the significant accuracy of the calibrated model in simulating these variables, with which the R~2, root mean square error(RMSE) and index of agreement(IOA) between simulated and observed variables were obviously improved than the original code. The sensitivities of the above variables to seeding date were also displayed to further explain the simulation error of the SiBcrop Model. Overall, the research results indicated the modified SiBcrop Model can be applied to simulate the growth and flux process of winter wheat growing in double cropping system in the NCP.  相似文献   

6.
The research of groundwater vulnerability is the basic work to protect the groundwater.For utilizing groundwater resource continuably,groundwater vulnerability evaluation is necessary.Useful reference to protect,exploit and utilize on groundwater resource are provided rationally.According to the real condition of Sanjiang Plain,the indexes system is established based on the traditional DRASTIC model.The new system includes the following seven indexes:Depth of Water,Net Recharge,Aquifer Media, Soil Media,Conductivity of the Aquifer,Land Utilizing Ratio and Populace Density.The related analysis appears that the system is rather reasonable.Because traditional methods,such as analytic hierarchy process and fuzzy mathematics theory,can't be avoided human interference in selection of weights,they could lead to an imprecise result.In order to evaluate the groundwater vulnerability reasonably,entropy weight coefficient method is applied for the first time,which provides a new way to groundwater vulnerability evaluation.The method is a model whose weights are insured by the calculation process,so the artificial disturb can be avoided.It has been used to evaluate the groundwater vulnerability in Sanjiang Plain.The satisfied result is acquired.Comparably,the same result is acquired by the other method named projection pursuit evaluation based on real-coded accelerating genetic algorithm.It shows that entropy weight coefficient method is applicable on groundwater vulnerability evaluation.The evaluation result can provide reference on the decision-making departments.  相似文献   

7.
流域不透水面及其变化信息提取(英文)   总被引：3，自引：0，他引：3  
Impervious surface is one of the important parameters of valley water circular simulation,scientific estimation for which has significant and practical value for the urban water quantity and process simulation,diffuse pollution estimating and the forecast of climate changes.The objective of this research is to get the information of impervious surface and its dynamic change.Through the computer-assisted field method,the technologies of decision tree and data mining were applied to withdraw the impervious surface information in research region by the Landsat TM data in 1988,1994 and 2002.The results suggested that the accuracy of impervious surface information extraction in the study area arrived above 94.4% in 2002 image.On this basis,the mixed method was used to extract the location and the types of the impervious surface change.The overall accuracy of monitoring reached 89%,which meets the demand of the hydrological models.  相似文献   

8.
双价抗虫转基因大豆抗苜蓿夜蛾分析(英文)   总被引：4，自引：1，他引：3  
[Objective] The aim of the research was to analyze the resistance of binary insect-resistant transgenic soybean to Heliothis viriplaca.[Method]In this experiment, resistance analysis of the stabilized binary insect-resistant transgenic soybean to Heliothis viriplaca was conducted in lab and in field conditions.[Result] The results indicated that the leaves of insect-resistant transgenic soybeans T5-150 and T5-195 showed lighter damage than those of non-transgenic soybeans. Meanwhile, the Heliothis viriplaca larvae fed on leaves of these two transgenic soybeans were characterized by less leaf consumption, shortening survival day, slower development and less pupation.[Conclusion]It was concluded that insect-resistance of transgenic soybean to Heliothis viriplaca was increased dramatically and the research provided a reference for selecting binary insect-resistant transgenic soybean to Heliothis viriplaca.  相似文献   

9.
In this paper, authors established a farmer crop selection model(FCS) for the three provinces of Liaoning, Jilin and Heilongjiang of the Northeast China. With linking to the environmental policy integrated climate model(EPIC), the simulated results of FCS model for maize, rice and soybean were spatialized with 1 km×1 km grids to obtain cropping pattern. The reference map of spatial distribution for the three staple crops acquired by remote sensing imageries was applied to validate the simulated cropping pattern. The results showed that(1) the total simulation accuracy for the study area was 78.62%, which proved simulation method was applicable and feasible;(2) simulation accuracy for Jilin Province was the highest among the three provinces with a rate of 82.45% since its simple cropping system and not complex topography;(3) simulation accuracy for maize was the best among the three staple crops with a ratio of 81.14% because the study area is very suitable for maize growth. We hope this study could provide the reference for cropping pattern forecasting and decision-making.  相似文献   

10.
In order to improve the image segmentation performance of cotton leaves in natural environment, an automatic segmentation model of diseased leaf with active gradient and local information is proposed. Firstly, a segmented monotone decreasing edge composite function is proposed to accelerate the evolution of the level set curve in the gradient smooth region. Secondly, canny edge detection operator gradient is introduced into the model as the global information. In the process of the evolution of the level set function, the guidance information of the energy function is used to guide the curve evolution according to the local information of the image, and the smooth contour curve is obtained. And the main direction of the evolution of the level set curve is controlled according to the global gradient information, which effectively overcomes the local minima in the process of the evolution of the level set function. Finally, the Heaviside function is introduced into the energy function to smooth the contours of the motion and to increase the penalty function Φ(x) to calibrate the deviation of the level set function so that the level set is smooth and closed. The results showed that the model of cotton leaf edge profile curve could be obtained in the model of cotton leaf covered by bare soil, straw mulching and plastic film mulching, and the ideal edge of the ROI could be realized when the light was not uniform. In the complex background, the model can segment the leaves of the cotton with uneven illumination, shadow and weed background, and it is better to realize the ideal extraction of the edge of the blade. Compared with the Geodesic Active Contour(GAC) algorithm, Chan-Vese(C-V) algorithm and Local Binary Fitting(LBF) algorithm, it is found that the model has the advantages of segmentation accuracy and running time when processing seven kinds of cotton disease leaves images, including uneven lighting, leaf disease spot blur, adhesive diseased leaf, shadow, complex background, unclear diseased leaf edges, and staggered condition. This model can not only conduct image segmentation of cotton leaves under natural conditions, but also provide technical support for the accurate identification and diagnosis of cotton diseases.  相似文献   

11.
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12.
MicroRNA(miRNA) is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae.  相似文献   

13.
Indoor microclimate is important for crop production and quality in greenhouse cultivation.This paper focuses on microclimate study based on a computational fluid dynamics(CFD) model of a typical plastic greenhouse(with a sector shape vertical cross-section) popularly used in central China.A radiation model is added into the CFD model so as to simulate coupling of convective transfers and radiative exchanges at the cover and the roof,instead of using the usual coupling approach based on energy balance.In addition,a fractal permeability model is innovatively adopted in the modeling of the crop canopy.Compared the numerical results with measured experimental data,the model simulation is proved with success.This model then is used to explore the microclimate variable distributions in the greenhouse.It shows that the airflow pattern,temperature and humidity profiles are different from those in a sawtooth Mediterraneantype greenhouse.The study suggests that this deliberately developed CFD model can be served as a useful tool in macroclimate research and greenhouse design investigating.  相似文献   

14.
A robust repetitive control scheme is used to improve the rate smoothness of a brushless DC motor (BLDCM) driven test turntable. The method synthesizes variable structure control (VSC) laws and repetitive control (RC) laws in a complementary manner. The VSC strategy can stabilize the system and suppress uncertainties, such as the aperiodic disturbance and noises, while RC strategy can eliminate the periodic rate fluctuation in a steady state. The convergence of the repetitive learning process is also guaranteed by VSC. A general nonlinear system model is discussed. The model can be considered as an extension of BLDCMs. The stability and asymptotic position tracking performance are validated by using Lyapunov functions. Simulation results show the effectiveness of the proposed approach for improving the rate smoothness.  相似文献   

15.
DEA is a new research field in operations research. It has unique virtues in dealing with assessment problem with multi-inputs especially multi-outputs. In this paper, DEA model of DC2R^ε has been applied to evaluate the relative efficiency of several different schemes of industrial structure adjustment of agriculture and finally select the optimal scheme. Furthermore, the inferior scheme has been improved according to some useful insights got from DEA model.  相似文献   

16.
DEA is a nonparametric method used in operation researches and economics fields for the evaluation of the production frontier. It has distinct intrinsic which is worth coping with assessment problems with multiple inputs in particular with multiple outputs. This paper used Dε C2 R model of DEA to assess the comparative efficiency of the multiple schemes of agricultural industrial structure, at the end we chose the most favorable also known as "OPTIMAL" scheme. In addition to this, using some functional insights from DEA model non optimal schemes or less optimal schemes had also been improved to some extent. Assessment and selection of optimal schemes of agricultural industrial structure using DEA model gave a greater and better insight of agricultural industrial structure and was the first of such researches in Pakistan.  相似文献   

17.
The aim of this research is to identify the most suitable land for forestry, afforestation and rangeland management in Hamadan province. This research has been accomplished using Makhdoum＇s model. In this research 30 digital data layers are used. The Geographic Information System （GIS） has been used as main tool and overlay method has been used to implement the mentioned model. The results of this research revealed that the extent of favorite areas for fifth grade forestry, favorite areas for fourth grade afforestation, and favorite areas for third grade and fourth grade range management in the studied area. Based on the results of this research, the studied area has limited potentials for forestry and afforestation activities. The obtained results of evaluation also showed that the rangelands of Hamadan province are extremely poor. Since the rangelands have a substantial role in preservation of soil and water, therefore it is necessary to take appropriate measures for better exploitation of rangelands.  相似文献   

18.
Ameliorating waste treatment by technological improvements affects the economic and the ecological-environment benefits of intensive pig production. The objective of the research was to develop and test a method to determine the technical optimization to ameliorate waste treatment methods and gain insight into the relationship between technological options and the economic and ecological effects. We developed an integrated bio-economic model which incorporates the farming production and waste disposal systems to simulate the impact of technological improvements in pig manure treatment on economic and environmental benefits for the case of a pilot farm in Beijing, China. Based on different waste treatment technology options, three scenarios are applied for the simulation analysis of the model. The simulation results reveal that the economic-environmental benefits of the livestock farm could be improved by reducing the cropland manure application and increasing the composting production with the current technologies. Nevertheless, the technical efficiency, the waste treatment capacity and the economic benefits could be further improved by the introduction of new technologies. It implies that technological and economic support policies should be implemented comprehensively on waste disposal and resource utilization to promote sustainable development in intensive livestock production in China.  相似文献   

19.
The author considered the influences of several weather factors, such as air temperature, sunlight, saturation deficiency, wind speed and so on to forecasting the water requirement of well irrigation rice based on Artificial Neutron Network. Through dealing with the time series of water requirement and its influence factors, the author applied the multi-dimension data correlation analysis to ensure the net structure. Thus, the ANN model to forecast the water requirement of well irrigation rice has been built. By means of the ANN model, uncertainty relation between water requirement and many influence factors among the interior and exterior can be discovered. The results of ANN model is good, and can provide some references for establishing the water saving irrigation system.  相似文献   

20.
Ameliorating waste treatment by technological improvements affects the economic and the ecological-environment benefits of intensive pig production.The objective of the research was to develop and test a method to determine the technical optimization to ameliorate waste treatment methods and gain insight into the relationship between technological options and the economic and ecological effects.We developed an integrated bio-economic model which incorporates the farming production and waste disposal systems to simulate the impact of technological improvements in pig manure treatment on economic and environmental benefits for the case of a pilot farm in Beijing,China.Based on different waste treatment technology options,three scenarios are applied for the simulation analysis of the model.The simulation results reveal that the economic-environmental benefits of the livestock farm could be improved by reducing the cropland manure application and increasing the composting production with the current technologies.Nevertheless,the technical efficiency,the waste treatment capacity and the economic benefits could be further improved by the introduction of new technologies.It implies that technological and economic support policies should be implemented comprehensively on waste disposal and resource utilization to promote sustainable development in intensive livestock production in China.  相似文献   

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