scholarly journals Dynamic balance between supply and demand of cultivated land at multi-measures

2003 ◽  
Vol 6 (4) ◽  
pp. 73-75
Author(s):  
Liu Yanfang ◽  
Zhu Guorui
2015 ◽  
Vol 15 (4) ◽  
pp. 817-824 ◽  
Author(s):  
Jing Peng ◽  
Ximin Yuan ◽  
Lan Qi ◽  
Qiliang Li

Water resources supply and demand has become a serious problem. Water resources allocation is usually a multi-objective problem, and has been of concern for many researchers. In the north of China, the lack of water resources in the Huai River Basin has handicapped the development of the economy, especially badly in the low-flow period. So it is necessary to study water resources allocation in this area. In this paper, a multi-objective dynamic water resources allocation model has been developed. The developed model took the overall satisfaction of water users in a time interval as the objective function, applied an improved simplex method to solve the calculation, considered the overall users' satisfaction variation with time, and followed the principle that the variation of the system satisfaction within adjacent periods of time must be minimal. The established model was then applied to the Huai River, for the present situation (2010), short-term (2020) and long-term (2030) planning timeframes. From the calculation results, the overall satisfaction in late May and mid September in 2030 was 0.65 and 0.70. After using the model allocation optimization, the overall satisfaction was improved, increasing to 0.78 and 0.79, respectively, thus achieving the dynamic balance optimization of water resources allocation in time and space. This model can provide useful decision support in water resources allocation, when it is used to alleviate water shortages occurring in the low-flow period.


2013 ◽  
Vol 33 (6) ◽  
pp. 1872-1880 ◽  
Author(s):  
施开放 SHI Kaifang ◽  
刁承泰 DIAO Chengtai ◽  
孙秀锋 SUN Xiufeng ◽  
左太安 ZUO Taian

2021 ◽  
Vol 5 (4) ◽  
pp. 1-24
Author(s):  
Jianguo Chen ◽  
Kenli Li ◽  
Keqin Li ◽  
Philip S. Yu ◽  
Zeng Zeng

As a new generation of Public Bicycle-sharing Systems (PBS), the Dockless PBS (DL-PBS) is an important application of cyber-physical systems and intelligent transportation. How to use artificial intelligence to provide efficient bicycle dispatching solutions based on dynamic bicycle rental demand is an essential issue for DL-PBS. In this article, we propose MORL-BD, a dynamic bicycle dispatching algorithm based on multi-objective reinforcement learning to provide the optimal bicycle dispatching solution for DL-PBS. We model the DL-PBS system from the perspective of cyber-physical systems and use deep learning to predict the layout of bicycle parking spots and the dynamic demand of bicycle dispatching. We define the multi-route bicycle dispatching problem as a multi-objective optimization problem by considering the optimization objectives of dispatching costs, dispatch truck's initial load, workload balance among the trucks, and the dynamic balance of bicycle supply and demand. On this basis, the collaborative multi-route bicycle dispatching problem among multiple dispatch trucks is modeled as a multi-agent and multi-objective reinforcement learning model. All dispatch paths between parking spots are defined as state spaces, and the reciprocal of dispatching costs is defined as a reward. Each dispatch truck is equipped with an agent to learn the optimal dispatch path in the dynamic DL-PBS network. We create an elite list to store the Pareto optimal solutions of bicycle dispatch paths found in each action, and finally get the Pareto frontier. Experimental results on the actual DL-PBS show that compared with existing methods, MORL-BD can find a higher quality Pareto frontier with less execution time.


2014 ◽  
Vol 1070-1072 ◽  
pp. 1524-1533
Author(s):  
Tao Yan ◽  
Zhan Zhan Qu ◽  
Dong Hui ◽  
Yun Jia Liu ◽  
Peng Fei Jia ◽  
...  

In the new energy power generation process, because it’s difficult to balance the dynamic energy and the system operation cost is high, the paper puts forward the basic structure of the commercial virtual power plant based on BESS system, then discuss the proper run mode of the virtual power plant to maximize the total revenue. On the basis of the electricity price of the Chinese typical areas and the cost of the BESS system, the paper builds the mathematical model of the economic benefits of the virtual power plant based on BESS system. This paper also builds the regulation optimization simulation model of the virtual power plant based on the aim of maximizing the overall profit of the energy supply and demand sides, and calculates the dynamic balance elements and optimization optimal power output value based on optimization algorithm. The simulation results show that using the virtual power plant based on BESS system to peak load shifting and control frequency is feasible in the economy.


2017 ◽  
Vol 9 (1) ◽  
pp. 95 ◽  
Author(s):  
Lin Lin ◽  
Ziran Ye ◽  
Muye Gan ◽  
Amir Shahtahmassebi ◽  
Melanie Weston ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1666
Author(s):  
Yan Chen ◽  
Weizhong Chen

In order to promote the efficient use of resources and the sustainable development of the economy in Jiangsu Province, it is particularly important to ease the contradiction between water supply and demand on the basis of realizing the coordinated development of the water–energy–food (WEF) nexus. With the aim of a dynamic balance of water resources, this paper used system dynamics (SD) to build a WEF nexus SD model that focused on studying the specific supply-and-demand mechanism of water resources in each subsystem. Then, Jiangsu Province was taken as an example to perform simulation research on the regional water dynamic balance to explore effective policies for increasing water supply and decreasing water demand. The results showed that the imbalance of water resources will remain severe in the next few years. To relieve the imbalance, it will be helpful to promote the energy utilization of straw, improve the irrigation efficiency, adjust the crop planting structure, and require residents to strictly follow the water quota. An important advancement in this study is the simulation of the water resources supply-and-demand mechanism in each subsystem from the perspective of the WEF nexus.


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