关键词： distributed economic model predictive control   process safety   computation time  

摘要： Achieving operational safety of chemical processes while operating them in an economically-optimal manner is a matter of great importance. Our recent work integrated process safety with process control by incorporating safety-based constraints within model predictive control (MPC) design;however, the safety-based MPC was developed with a centralized architecture, with the result that computation time limitations within a sampling period may reduce the effectiveness of such a controller design for promoting process safety. To address this potential practical limitation of the safety-based control design, in this work, we propose the integration of a distributed model predictive control architecture with Lyapunov-based economic model predictive control (LEMPC) formulated with safety-based constraints. We consider both iterative and sequential distributed control architectures, and the partitioning of inputs between the various optimization problems in the distributed structure based on their impact on process operational safety. Moreover, sufficient conditions that ensure feasibility and closed-loop stability of the iterative and sequential safety distributed LEMPC designs are given. A comparison between the proposed safety distributed EMPC controllers and the safety centralized EMPC is demonstrated via a chemical process example. (C) 2017 American Institute of Chemical Engineers

关键词： Climate change   Energy policy   Energy transition   Green investments   Agent-based modeling   Learning by doing  

摘要： Climate-economic modeling often relies on macroeconomic integrated assessment models (IAMs) that in general try to capture how the combined system reacts to different policies. Irrespective of the specific modeling approach, IAMs suffer from two notable problems. First, although policies and emissions are dependent on individual or institutional behavior, the models are not able to account for the heterogeneity and adaptive behavior of relevant actors. Second, the models unanimously consider mitigation actions as costs instead of investments: an arguable definition, given that all other expenditures are classified as investments. Both are challenging if the long-term development of climate change and the economy shall be analyzed. This paper therefore proposes a dynamic agent-based model, based on the battle of perspectives approach (Janssen [1];Janssen and de Vries [2];Geisendorf [3, 4]) that details the consequences of various behavioral assumptions. Furthermore, expenditures for climate protection, e.g., the transition of the energy system to renewables, are regarded as investments in future technologies with promising growth rates and the potential to incite further growth in adjoining sectors (Jaeger et al. [5]). The paper analyzes how a different understanding of climate protection expenditures changes the system's dynamic and, thus, the basis for climate policy decisions. The paper also demonstrates how erroneous perceptions impact on economic and climate development, underlining the importance to acknowledge heterogeneous beliefs and behavior for the success of climate policy.

关键词： Economic model predictive control   Pump scheduling approach   Two-layer control scheme   Non-linear differential-algebraic equations   Water distribution networks  

摘要： This paper addresses a non-linear economic model predictive control (EMPC) strategy for water distribution networks (WDNs). A WDN could be considered as a non-linear system described by differential-algebraic equations (DAEs) when flow and hydraulic head equations are considered. As in other process industries, the main operational goal of WDNs is the minimisation of the economic costs associated to pumping and water treatment, while guaranteeing water supply with required flows and pressures at all the control/demand nodes in the network. Other operational goals related to safety and reliability are usually sought. From a control point of view, EMPC is a suitable control strategy for WDNs since the optimal operation of the network cannot be established a priori by fixing reference volumes in the tanks. Alternatively, the EMPC strategy should determine the optimal filling/emptying sequence of the tanks taking into account that electricity price varies between day and night and that the demand also follows a 24-hour repetitive pattern. On the other hand, as a result of the ON/OFF operation of parallel pumps in pumping stations, a two-layer control scheme has been used: a non-linear EMPC strategy with hourly control interval is chosen in the upper layer and a pump scheduling approach with one-minute sampling time in the lower layer. Finally, closed-loop simulation results of applying the proposed control strategy to the D-Town water network are shown. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Deforestation   Global environmental change  

摘要： Tropical deforestation has been one of the most significant global environmental changes of recent decades and has spurred a substantial academic literature. Despite this, the empirical literature provides inconsistent evidence on the role of basic economic determinants of deforestation such as income and population. The authors suggest that one explanation for this inconsistency is a tendency to use incomplete or incorrect dynamic regression specifications. They derive three plausible dynamic empirical model specifications and compare their performance both with each other and with an ad hoc model typical of those used in the literature. Statistical tests support the use of more completely specified models which allow for dynamic adjustment of forest cover.

关键词： 产业经济   职业教育   供需失衡   结构性矛盾   经济模型  

摘要： 受多种因素影响,职业教育供需问题日益突出,很多专家对此开展了大量研究,比较发现,已有研究成果都是基于现实的供需表象进行分析,思辨性强而论据不足,难免影响分析的质量,本文创新性的提出基于经济学模型开展职教供需问题探索,指出职业教育产生供需失衡的本质原因是技术技能型人才给产业经济创造的总效用未能满足其人资需求预算,同时从供给弹性的角度,分析了职业教育供需失衡后的反应路径,并初步探讨了产业经济对技术技能型人才的需求的计算模型,对深化职业教育供给侧结构性改革有一定的指导意义。

关键词： 需求侧管理   电—热混合能源系统   经济模型   储能装置   优化调控  

摘要： 我国"十三五"节能减排工作以多能源合利用及需求侧管理(demand-sidemanagement,DSM)作为我国提高终端能效重点推广的用能模式。未来的热-电混合能源系统及需求侧管理涵盖多种能源资源,涉及多元主体,受多种因素的影响。为了协调能源系统的多种影响因素,对热一电混合能源系统的基础模型进行研究,提出了需求侧管理优化调控的经济模型。考虑各时段储能装置的状态,对关键影响因素进行详细建模。通过算例验证了模型的优越性以及对不同储能情景下影响因素变动的优化调控,为进一步挖掘我国电力需求侧资源,优化更复杂的热—电混合能源系统提供借鉴。

关键词： 风光互补供暖系统   热平衡模型   经济模型   遗传算法   经济分析  

摘要： 针对秦皇岛地区风力资源丰富、太阳辐射量充足的特点,设计了一种风电-太阳能集热-市电联合供暖系统,并建立了热平衡模型和经济模型。设置系统的寿命周期分别为10,15,20a,从投资的角度利用遗传算法对经济模型进行了全局优化。与传统燃煤供暖方式对比结果显示,该系统在15a和20a的运行周期内比传统供暖方式具有更好的经济效益和社会效益,在农村地区具有广阔的应用前景。

关键词： Security cost-benefit analysis   Security cost-effectiveness analysis   Physical security measures   Security decision-making   Chemical industry   Environmental accident  

摘要： Several recent events raised the attention toward possible major accidents triggered by external acts of interference in industrial facilities. In particular, a growing concern is present with respect to the intentional release of dangerous substances resulting in environmental and eco-terroristic attacks. Therefore, optimal selection and allocation of preventive security measures is becoming more important for decision-makers. Despite the existence of economic models supporting the decision-making process, their applications within the chemical industry Security context are relatively limited. This study describes a specific model for economic analysis and selection of physical security measures, with respect to potential environmental and eco-terroristic attacks in chemical facilities. An example of application to a relevant case study is presented to show the model capabilities. Site-specific analysis of the baseline physical security system performance allows comparing the costs of different security upgrades with the benefits related to either prospective or retrospective losses, meanwhile accounting the uncertainties related to the threat probability. Selection of the most profitable security measures within budget constraints and definition of economic indicators are the main outputs of the model, in order to support decision-making processes for allocation of security barriers. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： R10   R13   O18  

摘要： Urban agglomeration has attracted attentions of urban planners, economists, and policymakers. For the sake of urban agglomeration simulation, this paper attempts to develop a computable urban economic (CUE) model incorporated with economies of scale, through the approach of new economic geography. It is assumed that each firm produces a product variant in a monopolistic competition market, and the number of firms is explicit and determined endogenously. The Dixit-Stiglitz type utility function with product variety is adopted into the households' behavior to reflect consumers' preference for variety. On the other hand, internal increasing returns to scale and fixed cost are introduced in firms' behavior to extend the model with economies of scale. The model's parameter estimations and calibration are conducted on the basis of empirical data from several approved sources for Changzhou in 2008. Numerical computations are implemented by employing the extended CUE model incorporated with economies of scale to explain and examine how the urban agglomeration comes into being. Simulation results show that the extended model incorporated with economies of scale is able to commendably represent the urban agglomeration mechanism, providing a promising simulation tool for urban planning and policymaking.

关键词： 天然表面活性剂   Designer   成本分析   经济评估   运营成本   生产成本   经济模型   软件开发  

摘要： 11成本分析在建设和运作工厂之前,工艺的设计和经济评估是很重要的,这需要结合工程学的知识[66]。总体成本分析包括评估资本和运营开支。基于由Superpro Designer模拟软件开发的工艺经济模型,由葡萄糖和高油酸的葵花籽油生产907 00 t的槐糖脂的年运营成本为2.68亿美元,单位生产成本每千克2.95美元。