关键词： Stochastic processes   Diseases   Convergence   Predictive control   Modeling   Nickel   Epidemic processes   model predictive control   networked systems  

摘要： In this paper, we develop a robust economic model predictive controller for the containment of stochastic susceptible-exposed-infected-vigilant (SEIV) epidemic processes, which drives the process to extinction quickly, while minimizing the rate at which control resources are used. The study we present here is significant in that it addresses the problem of efficiently controlling general stochastic epidemic systems without relying on mean-field approximation, which is an important issue in the theory of stochastic epidemic processes. This enables us to provide rigorous convergence guarantees on the stochastic epidemic model itself, improving over the mean-field type convergence results of most prior work. There are two primary technical difficulties addressed in treating this problem: 1) constructing a means of tractably approximating the evolution of the process so that the designed approximation is robust to the modeling error introduced by the applied moment closure and 2) guaranteeing that the designed controller causes the closed-loop system to drive the SEIV process to extinction quickly. As an application, we use the developed framework for optimizing the use of quarantines in containing an SEIV epidemic outbreak.

关键词： Agriculture waste processing   Dairy manure   Anaerobic digestion   Hydrothermal liquefaction   Bioenergy   Techno-economic analysis  

摘要： There is increasing global interest and policies being enacted to lower greenhouse gas emissions, especially from the agricultural sector. In the U.S. for example, states with large dairy operations may combine proven manure valorization technologies, such as anaerobic digestion and hydrothermal liquefaction. Sustainable manure treatment would increase the recovery of energy and other useful co-products, namely biogas, biocrude oil and hydro-char as well as lower the environmental impacts. In this study, the economic feasibility of implementing a centralized bioenergy system in New York State was investigated. The feasibility of this transformation depends on many factors, including capital costs, discount rates, and other financing arrangements, electricity selling prices, incentives and farm sizes and locations. For a large-scale implementation in New York State accounting for nearly 50% of the state's dairy farms, our model of a distributed, hybrid anaerobic/hydrothermal system was shown to treat 590 million liters of wet manure per day, producing 607 million kWh of electricity, 162,000 L of biocrude oil and 117,000 kg of hydro-char per day. Electricity selling price is a critical factor. Increasing the electricity selling price from wholesale ($0.06/kWh) to retail ($0.18/kWh) increased the net present value from $395 million to $1.5 billion (considering a 40-year project lifetime). (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Subspace system identification   Price-based demand response   State-space model   Black box modelling   Mixed-integer linear program   Optimal control  

摘要： Dynamic solar shading devices are an effective mean to avoid overheating in buildings due to excessive solar heat gains. They can also be used to affect the heat balance of buildings;they can be on e.g. during nighttime to reduce space heating or retracted to increase night cooling. The shading control system can utilize this feature to obtain energy cost savings and reduce peak consumption. However, it is difficult to define optimal rule-based control strategies that minimize overheating and energy costs simultaneously. In this paper, we therefore propose an economic model predictive control (E-MPC) scheme for space heating where solar shading is included as an additional control variable. The proposed scheme employs black-box models, as they are 'cheap' to create from data;this is important for a widespread deployment of E-MPC in practice. The study was based on co-simulation experiments where EnergyPlus models represented the actual building and it was hereby demonstrated that the proposed E-MPC outperformed two rule-based controllers with respect to reducing overheating, energy costs and peak consumption. Shading also turned out to be valuable for north facing rooms where it reduced costs and peak consumptions compared to an MPC without shading. The energy-related benefits of the proposed E-MPC scheme can be regarded as 'an added value' that can be used for economic justification of an investment in dynamic solar shading devices. (C) 2019 Elsevier B.V. All rights reserved.

关键词： 交通系统管治   边际社会成本   环境成本   交通拥堵费  

摘要： 城市交通的投资和管理是交通决策的重大问题,如何在不同的供给、需求结构下,制定合理可行、与时俱进的交通政策是管理者需长期面对的课题。交通系统管治的内涵因城市发展阶段而变化,但究其理论根本是使边际出行在各种出行方式中所造成的社会成本的增量相等。STEM(Strategic Technical-Economic Model)模型为决策提供了这样一个理论和操作工具,并以此为基础模拟了巴黎大区的几项交通政策。交通税费的合理配置能够有效缩减私人成本和社会成本的分离,使出行消耗的社会资源内部化,从而实现城市交通系统的最优运行。

关键词： 时滞   收获   Hopf分支   稳定性  

摘要： 研究了一类具有Michaelis-Menten收获率和时滞的微分代数生态经济模型的稳定性和Hopf分支问题。基于分支理论和稳定性理论,以时滞为分支参数,分析了系统在正平衡点处的特征方程,得到了正平衡点局部稳定的条件,进而得到Hopf分支产生的相关稳定性判据和条件,并进行数值模拟以说明分析结果。

关键词： Liquid desiccant   EMPC   Dynamic modeling   Energy conversation   ANFIS   Genetic Algorithm  

摘要： As a good alternative to cooling-based air dehumidification, Liquid Desiccant Air Conditioning (LDAC) has drawn increasing attention for energy saving in large-scale public buildings. However, available investigations mostly pay attention to the dehumidification performance analysis and optimization based on steady-state models. Dynamic control issues for LDAC are rather important to the system performance and economic cost under the changing working conditions, such as the changing setting points of indoor air conditions and sensible/latent loads in occupied space. In this study, a dynamic model based on the Adaptive Neuro-Fuzzy Inference System (ANFIS) method is established to describe the system output air temperature and humidity ratio of LDAC dynamically with varied input conditions. The verification results show that a good agreement can be found between the prediction results from the proposed model and the experimental data with the relative errors less than 2% for outlet air temperature and less than 4% for outlet air humidity ratio, respectively. An EMPC strategy is designed based on the proposed dynamic model for LDAC by solving a receding optimization problem considering tracking error, control efforts rate, and energy consumption as the objective functions with Genetic Algorithm (GA) to get optimal dynamic response and improve the energy efficiency as well. The simulation analysis shows the proposed EMPC strategy outperforms Proportional-Integral (PI) control with smaller tracking error, faster response, and higher energy efficiency. The average energy saving by the proposed EMPC strategy can reach up to 9.5%.

关键词： 多元空间经济模型   SBM-undesirable模型   长江经济带   区域板块化发展   区域经济一体化发展  

摘要： 推动长江经济带发展是关系国家发展全局的重大战略,探讨并研究如何在“共抓大保护,不搞大开发”的发展理念下,以长江经济带发展推动经济高质量发展具有重要的理论价值和现实意义。文章基于长江经济带发展特点,在“中心-外围”模型基础上建立修正多元空间经济模型,将长江经济带沿线11省市进行空间数理建模,并运用SBM-undesirable模型进行实证检验,进而系统性分析区域板块化模式和区域经济一体化模式哪种更适合长江经济带高质量发展。研究结果显示:区域板块化发展模式由于存在显著的行政壁垒影响,将导致经济要素在各主体之间流动存在较大难度,最终导致长江经济带发展出现平均化均衡,不利于长江经济带高质量发展,限制地区经济活力;区域经济一体化发展模式将不断削弱长江经济带内部各省市自身行政壁垒影响,改善区域内部贸易互通条件,进而提升经济要素在各省市之间流动的速度,最终促使长江经济带自发形成集聚化均衡,实现整体经济高质量发展;长江经济带优势产业空间集聚化转型存在一门槛值,而区域经济一体化模式将有效降低该门槛值,减少转型发展的投入,提高经济发展效率。

关键词： 东、黄海鲐   Pella-Tomlinson模型   生物经济模型  

摘要： 根据1998-2015年中国鲐灯光围网生产的统计数据、日本西海区水产研究所的评估结果和相关经济数据,基于Pella-Tomlinson模型推算东、黄海鲐的最大可持续产量(maximum sustainable yield,MSY)、生物经济平衡点(bioeconomic equilibrium,BE)和最大经济产量(maximum economic yield,MEY)以及相应的捕捞努力量。考虑不同的管理目标,对fMSY、fBE和fMEY取不同权重,设计出10种不同的捕捞计划,比较在不同捕捞方式下鲐5年、10年和20年的生物效益、经济效益和社会效益。研究发现:东、黄海鲐的资源丰度逐年下降;加强捕捞努力量的投入会对经济效益、产量和资源量造成严重的影响;权衡生物、经济和社会目标,确定策略10为最适捕捞策略,即fMSY、fBE和fMEY的权重取值分别为0.25、0.25和0.50,此策略下5年内累计的利润和产量分别为30.19亿元和132.02万t,5年后的资源量为86.73万t。

关键词： Supply chain management   Time-based competition   Heterogeneous customers   Variational inequalities   Multinomial logit function  

摘要： This paper presents an integrated model for time-cost competition between supply chains with heterogeneous customers. The firms in our model can offer various time options for their production/service to time-sensitive customers. This gives rise of a new concept of time-based supply chain, which we call T-chain, to be the basic element in the competition and extends the inter supply chain competition to a new dimension of time. Assuming the customers are heterogeneous in time-cost bi-criteria decision making, we integrate the discrete choice theory into supply chain network competition and formulate the equilibrium conditions as a multinomial logit based variational inequality problem. Numerical examples are presented for model illustration and managerial insights such as profit maximization for a firm who participates in this supply chain network. (C) 2019 Elsevier B.V. All rights reserved.

关键词： Robust   Structural estimation   Finite horizon dynamic programming  

摘要： We study an estimation approach that is robust to misspecifications of the dynamic economic model being estimated. Specifically, the approach allows researchers to focus on a particular sub-problem or sub-period of the optimizing agent's finite horizon and thus alleviates the need for assumptions regarding expectation formation about the (distant) future. This is accomplished by approximating a pseudo terminal period policy- or value function non-parametrically rather than fully specifying the remaining economic environment anticipated by agents until the terminal period. We illustrate through two Monte Carlo experiments the superior robustness of the approximate estimator compared to a standard full solution estimator.