In the Netherlands the greenhouse sector is a major user of energy. It accounts for 7% of the total national energy use and for 79% of the total energy use in agriculture. In order to sustain this sector on the long term, it is important that its use of energy is lowered. One way of reducing energy use by horticultural producers is investing in energy-saving systems. The purpose of this paper is to provide a better understanding of the investment behavior of firm operators in the adoption of energy-saving systems. Research objectives of the paper are (1) to analyze factors underlying the decision to invest, (2) to explore factors underlying the optimal size of investments. Three investment theories were used to construct an empirical model of investment. Consequently, this model was estimated in a two-stage procedure to analyze the factors influencing the decision of farmers to invest and the level of investments. The paper ends with policy implications. 相似文献
It is assumed that Agent-Based Modeling is a useful technique for water management issues. In particular, it may provide a suitable framework for representing irrigated systems. The objective of this paper is to demonstrate its potential for a specific use: research on irrigated systems’ viability in the Senegal River Valley. The main assumption to be verified is that Multi-Agent Systems constitute a suitable architecture to study theoretically irrigated systems’ viability using simulations. By using Multi-Agent Systems, virtual irrigated systems can be designed that might then be used as virtual laboratories. These virtual labs constitute an alternative when real labs cannot exist for some reason.
In this paper we report on experiments we have conducted using such virtual labs for exploring an Agent-Based Model through the simulation of scenarios. A scenario is defined as a triplet: an environment, a set of individual rules, a set of collective rules. It is evaluated according to the longevity of the irrigated system. An index is defined, based on the ratio of long-enduring simulations among a set of repetitions of a given scenario. Even if simulation results display significant diversity for a given scenario due to random factors in the processes simulated, the ratio of long-enduring simulations is repeatable. This entails to explore the overall behavior of the virtual irrigated system and to build theories concerning the viability of Senegalese irrigated systems. An example is given showing the need for strong coherence for a given environment among individual rules and collective rules. 相似文献
为了实现不同土壤水分管理下的CO 2气肥精细控制,建立了番茄作物不同生长阶段的光合速率预测模型。实验设置了4个CO 2浓度与3个土壤水分条件的交互处理,利用无线传感器网络长期实时监测温室内环境信息,采用LI-6400XT型光合速率仪定时采集作物净光合速率信息;并用BP神经网络分别建立了番茄苗期、花期和果期的光合速率预测模型。预测模型的验证结果表明,对于苗期预测模型,预测值与实测值之间的决定系数 R 2为0.925;花期预测模型的决定系数 R 2为0.920,果期预测模型的决定系数 R 2为0.958;番茄各生长期的光合速率预测模型均具有较高的预测精度。在不同土壤水分条件下改变CO 2浓度,得到的CO 2浓度与光合速率预测曲线与实测值相近,可反映实际土壤水分管理下的CO 2浓度最优值,对指导不同土壤水分条件下CO 2气肥的精细调控具有重要意义。 相似文献