关键词： Benchmark simulation model no. 2   Dosing control   Economic MPC   Struvite production   Water resource recovery  

摘要： Resource recovery from municipal wastewater has been a prime focus for a decade. Although several recovery processes already exist in the market today, the high cost of material, inherent disturbance in the influent quality, lack of real time monitoring of critical parameters, and lack of a robust automation system may result in suboptimal performance. This work attempts to construct a model based predictive control for optimal operation of a struvite recovery unit in a full scale WRRF. A multi-parameter based predictive control has been developed by implementing an Economic Model Predictive Controller (EMPC) for optimal dosing of magnesium hydroxide in a struvite recovery unit. The EMPC used customized objective function for real-time optimization of performance and economical parameters of the crystallization unit. The effectiveness of the proposed EMPC controller is verified through tests conducted on the Benchmark Simulation Model No. 2 (BSM2d.). The results obtained from the simulator-based evaluation of EMPC demonstrate a significant improvement in resource recovery at reduced operational costs. The economic advantages of implementing an EMPC compared to proportional and constant magnesium dosage has also been enumerated.

关键词： Circular economy   Cleaner production   Environmental management   Recycling   Resource efficiency   Business model  

摘要： Farmutil is one of the largest and most modern agro-food consortia operating in the Polish market, and has developed a sustainable development strategy for over four decades. The management system implemented in Farmutil exemplifies the application of basic elements of the circular economy in industrial practice by using cleaner technologies. The production management model at Farmutil has the form of a system of connected stream flows of materials and energy. The solution includes the prevention of environmental pollution through the implementation of new technologies, the reduction and reuse of waste, recycling and the recovery of materials and energy, the substitution of raw materials with waste and the use of processed waste as biofuel. The model is a system covering the full lifecycle of products, from cereal cultivation through to the production of industrial feed and poultry and pig breeding for the production of meat products. The information gained from the theoretical and empirical parts of the study shows the possibility of their use to create a policy which allows the widespread implementation of circular economy activities, not only by eco-friendly technological innovation, cleaner production or eco-efficient solutions for production and waste minimisation, but also at the organisational and social levels. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： 大数据   数量经济学   BP神经网络   CPI  

摘要： 大数据时代的来临,掀起了大数据与传统学科融合发展的热潮,探寻"大数据+数量经济学模型"的发展之路势在必行。本文运用文献计量分析,对大数据时代较有代表性的定量研究方法和模型进行分类梳理,并基于BP神经网络模型结合36个指标数据对中国居民消费价格指数(CPI)进行多元变量预测。研究表明,BP神经网络的预测结果最优。因此,未来要强化传统数量经济学的大数据化升级,注重非线性、非参数、模型自由化的研究方法在实际问题中的应用。

关键词： 全要素生产率   宏观经济模型   微观-宏观   综合集成  

摘要： 党的十九届四中全会明确提出,除劳动、资本、土地外,知识、技术、管理、数据也成为当代社会生产活动的重要投入要素,如何有效配置这些投入要素资源、提高投入要素质量、提升全要素生产率的贡献、推动经济社会实现高质量发展,是新时代中国经济问题研究面临的新任务。为了完成这一任务,必须进行跨学科联合攻关,发挥不同学科的综合优势。宏观经济问题研究的一个重要趋势是从微观到宏观,这主要依赖于数据、机理、计算三个方面的条件,三方面的进展都离不开跨学科的支持。随着综合集成、模拟仿真方法应用于我国经济社会发展领域的条件日益成熟,钱学森提出的综合集成、模拟仿真思路成为对中国经济问题进行跨学科研究的一条值得重视的途径,即通过研制和应用基于个体模型,让经济学更好地与其他学科实现跨学科发展,为中华民族的伟大复兴作出更大贡献。

关键词： 电力老旧资产   全寿命周期   经济寿命模型   资产失效率  

摘要： 电网老旧资产分析对实物资产管理、系统风险具有重要意义。本文采用全寿命周期理论与经济寿命模型对电力老旧资产进行了经济寿命、报废年限及资产失效率三方面的分析,并据此定义了老旧设备的年龄区间;最后结合某公司资产数据进行了详细的实证分析。

摘要： Background Decision-analytic models used in economic evaluations of disease-modifying therapies for relapsing-remitting multiple sclerosis (RRMS) have characterized disease progression and accrue quality-adjusted life-years from utility values based on the Expanded Disability Status Scale (EDSS), the occurrence of relapses, and progression to secondary-progressive multiple sclerosis (SPMS). The EDSS, used to characterize disability progression, has several limitations. If the EDSS is the only disability measure used in economic evaluations, the long-term clinical and economic implications of disease-modifying therapies may not be properly assessed. Objective The objective of this study was to explore if supplementary disability measures including the Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), and Paced Auditory Serial Addition Test (PASAT) significantly contribute additional information on health utility in RRMS and SPMS otherwise not captured by the EDSS and relapses and, therefore, should be considered in future economic evaluations of disease-modifying therapies. Methods Short-Form Six-Dimension utility scores were derived from the RAND 36-Item Health Survey 1.0 individual-level data available in the Multiple Sclerosis Outcome Assessment Consortium (MSOAC) Placebo Database. Repeated-measures mixed-effects models were conducted to estimate the effects of EDSS, T25FW, 9HPT (dominant and non-dominant hand), PASAT, and relapses on changes in utility over time, controlling for demographics. Results A higher level of EDSS, longer time to complete the T25FW test, and a recent relapse were significant predictors of lower utility in people with RRMS and SPMS. 9HPT and PASAT were not significant predictors. Conclusions This study suggests that in addition to EDSS and recent relapses, T25FW significantly predicts utility in RRMS and SPMS. These findings support the use of T25FW to supplement the EDSS and the occurrence of relapses to characterize the course of dise

关键词： Transport-reaction processes   EMPC   Constrained optimization   Performance improvement  

摘要： For transport-reaction processes with certain general cost functions indicating comprehensive profit, the existing linear-quadratic optimal control or model predictive control (MPC) methods may be conservative. Due to their spatial characteristics, dynamic evolutions and final target static spatial distributions under different control strategies may result in remarkable variation of operation performance. This article presents a novel economic model predictive control (EMPC) synthesis for systems described by hyperbolic/parabolic partial differential equations (PDEs) with pre-optimized static spatially distributed profile, from both convergence and performance points of view. Instead of deriving approximate ordinary differential equations (ODEs) and applying finite-dimensional control strategies, this work addresses the optimization and stabilization problem on the basis of infinite dimensional model itself, which is realized by Cayley-Tustin (CT) transformation without any type of spatial approximation. The accumulated economic cost, input/output constraints are explicitly considered in the finite horizon optimal control problem (FHOCP), with an additional energy-like contractive constraint accounting for closed-loop convergence toward the target optimal steady-state profile. By directly solving Lyapunov functions associated with PDEs models, the parameters in the FHOCP are suitably defined such that the composite EMPC system admits algorithm feasibility and closed-loop stability. Finally, the proposed method is applied to typical examples;numerical results indicates the effectiveness and remarkable performance improvement of the EMPC method compared to standard MPC results.

关键词： Adaptation   Agricultural sector   Climate change   Economic model   Optimal cropping pattern  

摘要： Climate change imposes adverse effects on water resources and agriculture in different regions of the world including Iran, so farmers need better adaptation to this phenomenon in order to maintain a steady livelihood. The present study aimed to analyze the future of water resources and agricultural sector affected by climate change in the Qarah Su Basin in Golestan province, Iran. The results indicate that the mean temperature will rise by 3.5 degrees C and the mean precipitation will decrease by 0.6 mm over the 2011-2040 period under the climate change scenario. Higher temperatures and lower rainfall in the hydrological sector will result in a decline in the river's runoff and consequently, a decline in the water allocated to the agricultural sector. The results of the economic model reveal that under climate change, crop acreages will decrease by 36% in Gorgan and 26% in Kordkuy and gross return will decrease by 10% and 8% versus the baseline year in these regions, respectively. The greatest decrease will happen for cotton due to its high water demand and low gross profit. But, no significant change will happen in its acreage in Bandar Torkman. To counteract the negative effects of climate change, the scenario of increasing irrigation efficiency and changing cropping type and pattern was applied. So, policymakers can use a combined model to mitigate the adverse impacts of climate change on the agricultural sector, thereby increasing the acreage of these crops in Gorgan and Kordkuy and improving the gross income of the agricultural sector in the three regions versus the climate change scenario. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： 主成分分析法   美国经济组成   熵权法  

摘要： 美国两位候选人拜登、特朗普在经济贸易、金融政策、国家治理层面以及其他社会保障层面有着不同的主张和政策,选举结果将对全球金融发展战略产生影响。分析美国经济构成。

ISBN: (纸本)9787547316696