Chengwei Lv

Equilibrium strategy-based optimization method for the coal-water conflict: A perspective from China

Environmental water problems have become increasingly severe, with the coal-water conflict becoming one of the most difficult issues in large scale coal mining regions. In this paper, a bi-level optimization model based on the Stackelberg-Nash equilibrium strategy with fuzzy coefficients is developed to deal with environmental water problems in large scale coal fields, in which both the groundwater quality and quantity are considered. Using the proposed model, and fully considering the relationship between the authority and the collieries and also the equilibrium between economic development and environmental protection, an environmental protection based mining quotas competition mechanism is established. To deal with the inherent uncertainties, the model is defuzzified using a possibility measure, and a solution approach based on the Karush-Kuhn-Tucker condition is designed to search for the solutions. A case study is presented to demonstrate the practicality and efficiency of the model, and different constraint violation risk levels and related results are also obtained. The results showed that under the environmental protection based mining quotas competition mechanism, collieries attempt to conduct environmentally friendly exploitation to seek greater mining quotas. This demonstrates the practicality and efficiency in the proposed model of reducing the coal-water conflict. Finally, a comprehensive discussion is provided and some propositions is given as a foundation for the proposed management recommendations.

Waste load equilibrium allocation: a soft path for coping with deteriorating water systems

Waste load allocation is always regarded as another efficient approach comparing with the technology-based approach to improve the water quality. This paper proposes a bi-level multi-objective optimization model for optimally allocating the waste load of a river basin incorporating some concerns (i) the allocation equity from the regional authority, (ii) maximal benefits from the subareas along the river, and (iii) the Stackelberg-Nash-Cournot equilibrium strategy between the upper and lower decision makers. Especially, a novel Gini coefficient for measuring the load allocation equity is defined by considering the economic level and waste water quantity. The applicability and effectiveness of the proposed model is demonstrated through a practical case based on the Tuojiang River, which is a typical basin with diversified industrial waste discharges in western China. Some operational suggestions are developed to assist the decision makers’ cope with deteriorating water systems.

Modelling diffusion for multi-generational product planning strategies using bi-level optimization

Two bi-level models for two-generation product diffusion are proposed to tackle the conflicts of sales and production departments.Continuous production strategy and production halt strategy are compared under supply constraints.The consumers are grouped into four categories according to the production scale and inventory capacity constraints.The multi-stage GA is designed to solve the optimum production capacity and time variables under two production strategies. When introducing new products, companies seek maximal profits by determining an optimal production plan and marketing strategy. However, if they have limited production capacity, there is a conflict between sales and production due to the differences in their respective goals. When two generations of the same product co-exist in the market, consumer behavior can have a significant influence on product diffusion. In this paper,consumers are divided into four categories based on supply constraints,and production strategies are classified into two distinct types. After modelling the demand diffusion and sorting the customer relationships into the different production strategies, two bi-level models for two-generation product diffusion are proposed,both of which take profit as the upper level goal and stable production as the lower level goal. An interactive dynamic programming based genetic algorithm (IDP-GA) is then designed to solve the bi-level models. The results found that scientific and practical production planning methods based on new product diffusion under supply constraints can achieve suitable results for both levels.

Power Plants Planning Modelling-Based Carbon Emission Allowance Allocation Problem with Changing Supply-Demand Relationship

This paper discusses a carbon emission allowance allocation problem from a regional authority’s perspective under a fuzzy environment, which is a multi-objective optimization process. Uncertain parameters are depicted as fuzzy variables and fuzzy expected value notions are introduced to cope with the uncertainty. A fuzzy logic controlled genetic algorithm is designed as a solution method to solve the above problem. Finally, the results of a case study for the carbon emission allowance allocation problem about China Southern Power Grid Company Limited are proposed to show the practicality and efficiency of the optimization method.

A seasonal changes-based equilibrium strategy for coal–water conflict: a case study at the Yanzhou coal field

Groundwater damage and pollution are now becoming the main obstacles to sustainable development for large-scale coal fields. In this paper, an equilibrium strategy-based bi-level optimization model under uncertain conditions is proposed to deal with such obstacles. The aim of the model is to establish an environmental protection-based mining quota competition mechanism to achieve sustainable development in Chinese large scale coal fields by fully considering the relationship between the local authority and the collieries as well as the influence on coal mining activities caused by the changing of the seasons. To deal with inherent uncertainties, the model is defuzzified using a combination of the fuzzy expected value and possibility measure and, to search for the solutions, an approach based on the Karush-Kuhn-Tucker condition is designed. The successful use of this model on a real world case demonstrates its practicality and efficiency. Sensitivity analyses under different constraint violation risk levels are also implemented. The results show that under an environmental protection-based mining quota competition mechanism, the collieries attempt to conduct environmentally friendly exploitation to seek greater mining quotas. Thus, demonstrating the guidance this model can provide to ensure sustainable development. Finally, by analyzing the results, some conclusions are provided to serve as the foundation for the proposed policy recommendations.