جستجوی مقالات مرتبط با کلیدواژه « Economic Modeling » در نشریات گروه « کشاورزی »

This research aimed to select essential features for modeling the cost of pressurized irrigation systems using the data of 515 drip irrigation projects in four parts, including the cost of pumping station and central control system (TCP), cost of on-farm equipment (TCF), cost of installation and operation on-farm and pumping station (TCI), and total cost (TCT). In the first stage, a database including 39 features influencing the cost of the mentioned sectors was prepared and the price of all projects (2006 to 2019) was updated for the base year of 2021. Then, feature selection was done with different algorithms in MATLAB environment and in two parts including (1) all features (39 features before and after the design stage) and (2) 18 features before the design phase (BD). The results showed that the amounts of RMSE and R2 for all the features were equal to 0.007 and 0.92, respectively, and for the BD section, they were equal to 0.003 and 0.89, respectively. Among the different algorithms for feature selection, support vector machine (SVM) and optimization algorithms (Wrapper) were identified as the best learner and feature selection method, respectively. The results of the evaluation criteria showed that the two LCA and FOA algorithms achieved the best estimation, and their error criterion in all the features were 0.0020 and 0.0018, respectively, while their correlations were 0.94 and 0.94. In the BD features, these criteria were 0.0006 and 0.95 for both algorithms, respectively. Finally, in the all features section, 10 out of 39 features and for BD section, 8 out of 18 were selected as the most effective features. The results of choosing the most effective features that affect the cost of different parts of the drip irrigation system can make the cost modeling of the systems simpler and faster and, while being useful for research works, it facilitates estimation and management of costs before implementation of each project.

Integrated watershed management is considered as a new principle for development planning and management of water and soil resources emphasizing on socio-economic characteristics of the region to sustainable livelihoods without vulnerability for plants and the residents of an area. This research, in line with the objectives of integrated management, has been carried out for modelling and evaluating the effects of ecological, socio-economic consequences resulting from the implementation of the proposed management plans on the vegetation changes with a focus on the problems in Simindasht catchment, located in Semnan and Tehran Provinces. After standardization of indices by distance method and weighing them, the scenarios were prioritized using multi-criteria decision-making technique. Trade-off analysis of the results indicates that in the integrated management of Simindasht catchment more than one single management solution, covering all aspects of the system can be recommended in different weighting approaches. The approach used herein, considering the results of different models and comparing the results, is an efficient tool to represent the watershed system as a whole and to facilitate decision making for integrated watershed management.

The main objective of this study is to simulate farmers’s response to the increasing prices of agricultural products policy in the cites of Qazvin province. The corn in city of Alborz and tomatoes in city of Abyek that have high volatility in the market price were studied. To achieve this goal, an economic modeling system consists of the Positive Mathematical Programming and State Wide Agricultural Production Function was used. In following the farmers’s response to the increasing prices of agricultural products policy under the scenarios 10, 20, 30, 40 and 50 percent was simulated and created changes in cropping pattern and farmer's gross profit were analyzed. The required data were related to the year 2011-2012 that with referring directly to the relevant organizations in Qazvin province were collected. The results showed that with increase in the price of tomatoes and corn, farmers cites of Abyek and Albrz tends to increase the acreage of these crops to achieve the more profits and decreases the acreage of products with lower returns. Also, the results showed that increases the farmer's gross profit of Abyek 4/18 to 20/39 percent with increasing the price of tomato and increases farmer's gross profit of Alborz 3/02 to 19/4 percent with increasing the price of corn. To effectiveness of the increasing prices of agricultural products policy, the use of supplementation policies in the supply side of inputs and products and also the use of auxiliary policies in the water resources side simultaneously with this police were proposed.