关键词： 县域经济   MATLAB   相关系数  

摘要： 通过马克思政治经济学和实验经济学的相关系数分析模型,以MATLAB的COR函数分析全州县域工业发展的状况和数据,试分析出全州县域工业发展进程相关性。在经济模型的基础上客观分析全州县域的工业发展,进一步总结出全州县工业发展的相关性。

关键词： 宏观经济模型   不确定性   方差控制   鲁棒跟踪  

摘要： 本文以宏观经济模型中的乘数加速数模型为基础,进一步考虑了不确定性对模型的影响,提出了具有不确定因素的乘数加速数模型。基于控制论理论,将宏观调控政策问题转化为控制论中的跟踪控制问题,并应用鲁棒方差方法求解控制律。根据控制律的求解结果,可以得到预期的政府宏观调控政策。从而表明经济模型在干扰和不确定因素的作用下,通过适当调整政府财政支出,及刺激居民消费支出以及投资支出的政策,可以使实际的经济系统跟踪预期的经济轨迹演变,并使系统达到稳定,并基于实际数据进行了模拟仿真。仿真结果表明,考虑不存在不确定性和白噪声干扰,在最优的政府财政支出策略下,GDP的实际输出值能较好地跟踪目标值,并且经济系统趋于稳定;当存在不确定性和干扰时,系统趋于稳定,且具有较好的动态和稳态性能。说明该算法有效地解决了模型参数的不确定性及外界对系统动态和稳态性能造成的影响。

关键词： 数量经济学   经济模型   前沿问题  

摘要： 数量经济学是数学化与定量化相结合的学科。作为我国的新兴学科,其最大的优势在于学科的交叉性,因此企业经济类学科无法替代数量经济学。我国的数量经济学虽然形成较晚,但成绩斐然。笔者在文章中对该学科的含义与内容及发展趋势中的前言问题进行阐述。

关键词： nonlinear systems   scheduling   production management   economic model predictive control   process control   process optimization   process economics   nonlinear processes  

摘要： Managing production schedules and tracking time-varying demand of certain products while optimizing process economics are subjects of central importance in industrial applications. We investigate the use of economic model predictive control (EMPC) in tracking a production schedule. Specifically, given that only a small subset of the total process state vector is typically required to track certain scheduled values, we design a novel EMPC scheme, through proper construction of the objective function and constraints, that forces specific process states to meet the production schedule and varies the rest of the process states in a way that optimizes process economic performance. Conditions under which feasibility and closed-loop stability of a nonlinear process under such an EMPC for schedule management can be guaranteed are developed. The proposed EMPC scheme is demonstrated through a chemical process example in which the product concentration is requested to follow a certain production schedule. (c) 2016 American Institute of Chemical Engineers AIChE J, 63: 1892-1906, 2017

关键词： Recursive method   Value function iteration   Dynamic programming   Climate-economy model  

摘要： A recursive method for solving an integrated assessment model of climate and the economy is developed in this paper. The method approximates a value function with a logarithmic basis function and searches for solutions on a set satisfying optimality conditions. These features make the method suitable for a nonlinear model with many state variables and various constraints. The method produces exact solutions to a simple economic growth model and is useful for solving more demanding models such as the well-known DICE model (dynamic integrated model of climate and the economy).

关键词： Economic MPC   Multi-model uncertainty   Offset-free   Stability  

摘要： Economic Model Predictive Controllers, consisting of an economic criterion as stage cost for the dynamic regulation problem, have shown to improve the economic performance of the controlled plant. However, throughout the operation of the plant, if the economic criterion changes - due to variations of prices, costs, production demand, market fluctuations, reconciled data, disturbances, etc. - the optimal operation point also changes. In industrial applications, a nonlinear description of the plant may not be available, since identifying a nonlinear plant is a very difficult task. Thus, the models used for prediction are in general linear. The nonlinear behavior of the plant makes that the controller designed using a linear model (identified at certain operation point) may exhibit a poor closed-loop performance or even loss of feasibility and stability when the plant is operated at a different operation point. A way to avoid this issue is to consider a collection of linear models identified at each of the equilibrium points where the plant will be operated. This is called a multi-model description of the plant. In this work, a multi-model economic MPC is proposed, which takes into account the uncertainties that arise from the difference between nonlinear and linear models, by means of a multi-model approach: a finite family of linear models is considered (multi-model uncertainty), each of them operating appropriately in a certain region around a given operation point. Recursive feasibility, convergence to the economic setpoint and stability are ensured. The proposed controller is applied in two simulations for controlling an isothermal chemical reactor with consecutive-competitive reactions, and a continuous flow stirred-tank reactor with parallel reactions. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： actuators   Economic Models   on-line model   Predictive control   Error of prediction   Stick Dosage Form   plant data   Process dynamics  

摘要： In this work, we present a data-driven methodology to overcome actuator faults in empirical model-based feedback control. More specifically, we introduce the use of a moving horizon error detector that quantifies prediction errors and triggers updating of the model used in the controller online when significant prediction errors occur due to the loss of one of the actuators. Model reidentification is conducted online using the most recent input/output data collected after the fault occurrence. The error-triggered online model identification approach can be applied to overcome various types of actuator faults, including the case where the value at which the actuator is stuck is known and the case where the value at which the actuator is stuck is unknown. The proposed methodology is applied in an economics-based feedback controller, termed economic model predictive control (EMPC), that uses a model obtained either from first-principles or from plant data to optimize plant economics online. Two different chemical process examples are considered in order to demonstrate the application of the proposed strategy. In the first example, application of the proposed scheme for the case where the value at which the actuator is stuck is known is demonstrated through a benchmark catalytic chemical reactor example where the actuator faults occur in the heat input causing shifts and variations in plant operating conditions. The second example demonstrates the case where the value at which the actuator is stuck is unknown. The proposed scheme was able to compensate for the variations in the plant caused by the actuator loss by obtaining more accurate models that are suitable for the new conditions and updating them in the EMPC architecture. Improved economic performance was obtained as the updated models were able to capture the process dynamics under the new conditions and provide better state predictions.

关键词： 量化宽松   价格粘性   产出与通胀效应  

摘要： 基于价格粘性的简约式宏观经济模型和利率传导渠道的理论分析得出,量化宽松具有正向的产出效应和通胀效应,实际产出具有负向的通胀效应。基于SVAR模型的累计脉冲响应检验结果表明,中国式量化宽松政策存在正向的产出效应和通胀效应,实际产出具有负向通胀效应。因此,适度宽松的货币政策与减税政策相结合有助于中国经济增速稳定与物价稳定。

关键词： renewable energy   biofuels   net energy balance   seed productivity   transesterification  

摘要： BACKGROUND: At commercial level, the biodiesel production process is well established for many types of feedstock. However, economic feasibility depends on regional fluctuating data, making each case unique. A calculation model to analyze the economic feasibility of biodiesel production from Jatropha curcas was developed, along with an analysis of the energetic balance derived from this process. RESULTS: Yucatan state has the cultivation surface to replace 10% of its fossil diesel fuel consumption with biodiesel. Two scenarios were studied: the use of biodiesel-fossil diesel blends B5 and B10. The net energy ratio (NER) of biodiesel production is 2.88, indicating that the system provides more energy than it consumes. The economic analysis indicates that biodiesel cost remains constant with production capacities of 10 000 m(3) year(-1) and higher. Field labor, pesticides, and fertilizers are the major costs at J. curcas plantations, representing 64.3, 16.3 and 11.5% of total biodiesel cost, respectively. The net present value (NPV) was always negative, proving that the biodiesel-jatropha chain is not economically viable. CONCLUSIONS: Actual seed productivity (1 495 kg ha(-1) year(-1)) must be increased 2.17 times to attain economic viability. Agricultural practices need to be enhanced in order to lower labor cost and the use of fertilizers. (C) 2016 Society of Chemical Industry

关键词： Economic models   Mathematical models   Economic systems   Economic policy   Economics  

摘要： A simple method to derive optimal steady states of multi-state dynamic economic systems with minimal assumptions on the underlying processes is developed. This is accomplished by an n-dimensional function defined over the n-dimensional state space in terms of the model's primitives. The location and stability properties of optimal steady state candidates are characterized by the roots and derivatives of this function. A resource management example illustrates the simplicity and applicability of the method.