Parallel hyper heuristic algorithm based on reinforcement learning for the corridor allocation problem and parallel row ordering problem

Hyper heuristics is a relatively new optimisation algorithm. Numerous studies have reported that hyper heuristics are well applied in combinatorial optimisation problems. As a classic combinatorial optimisation problem, the row layout problem has not been publicly reported on applying hyper heuristics to its various sub-problems. To fill this gap, this study proposes a parallel hyper-heuristic approach based on reinforcement learning for corridor allocation problems and parallel row ordering problems. For the proposed algorithm, an outer layer parallel computing framework was constructed based on the encoding of the problem. The simulated annealing, tabu search, and variable neighbourhood algorithms were used in the algorithm as low-level heuristic operations, and Q-learning in reinforcement learning was used as a high-level strategy. A state space containing sequences and fitness values was designed. The algorithm performance was then evaluated for benchmark instances of the corridor allocation problem (37 groups) and parallel row ordering problem (80 groups). The results showed that, in most cases, the proposed algorithm provided a better solution than the best-known solutions in the literature. Finally, the meta-heuristic algorithm applied to three low-level heuristic operations is taken as three independent algorithms and compared with the proposed hyper-heuristic algorithm on four groups of parallel row ordering problem instances. The effectiveness of Q-learning in selection is illustrated by analysing the comparison results of the four algorithms and the number of calls of the three low-level heuristic operations in the proposed method.     

水贫困指数在河西走廊三大内陆河流域的应用

水贫困指数提供了一种简单、易行的水资源评价方法,它通过资源、途径、能力、利用和环境5个方面来定量评价区域水资源的相对水平。运用主客观组合赋权法确定各分指标的权重,对河西走廊三大内陆河流域的水贫困指数进行了研究。结果表明:黑河流域、疏勒河流域、石羊河流域的水贫困指数分别为39.4、66.0、36.6,评价结果与客观情况基本相符。     

新时期面向品质提升的城市设计工作思路探讨——以沈阳金廊核心段城市设计为例

沈阳金廊在快速发展十年之后,迎来了对规划建设总结和提升的阶段,本文在分析其建设现状基础上,结合新时期中央城市工作会议精神,从追求品质增长、发挥公共价值、增强设计指导性三方面开展本轮城市设计工作,包括继续按照最初谋划的金廊整体功能结构和空间结构进行严格控制,着重对公共领域的品质进行提升,并打造未出让地块为示范项目树立标杆,最终落实成管控文件。     

Rescuing Big Rivers Damaged in Industrial Civilization

Large rivers with beautiful landscapes were dreamlands to the author. However, every time upon his arrival to riversides, he was shocked for the heavily polluted rivers that are dirty, messy, and smelling. Engineered dikes and dams made of concrete and steels for a greater height and hardness are built by cities along rivers. As more highways and railways built along rivers, vehicles run at a faster speed, scaring any life who wants to or has to access the water. Most of the tributaries are no longer free flow but end up as hard ditches and the water is polluted heavily. Forests and wetlands are being damaged and eroded. All of these are resulted from humans’ material desires and lack of respect for nature. Nevertheless, ecological civilization may encourage people to appreciate the beauty of nature and get a thorough understanding on river ecosystems and their services, accompanied by systematic planning and implementation of territorial ecological restoration. Moreover, laws and regulations on large river management should be put in place, and efforts should be made to break the worship of grey engineering approaches to flood control. It is expected that nature-based ecological approaches for a better resilience and sustainability in flood management can be more effective to ensure water safety.     

特色校园的塑造———浅析福州一中新校区设计

本文以福州第一中学新校区设计为例,从基地的自然环境入手,从学校的历史入手,提出了从建筑布局．山水校园,古朴风格,多元空间等几个方面来打造富有特色的校园建筑。     

从被动保护到保护性开发的城市生态廊道规划

城市生态廊道处于生态用地与建设用地间能量交换的前沿,对城市生态系统的维护具有重要作用。伴随城市的快速扩张,对于生态廊道用地空间传统的被动保护无法保证生态廊道系统的稳定性和完整性。为此,立足于城市生态可持续发展,提出了以保护性开发为导向的城市生态廊道规划策略,并以广州番禺片区生态廊道规划①实践为例,从廊道空间架构、保护性开发土地利用分级与控制、生态保护优先的产业布局及具较强可操作性的廊道生态用地空间导引等方面探讨了规划思路。     

Graph Theory and Open-space Network Design

A decision support system designed to aid the planning and creation of green-space or open-space networks is described. The system relies on data describing current land cover and existing conservation lands, and may be extended to include any number of other ancillary data sources. The system incorporates algorithms developed in the fields of graph theory and operations research but also describes two new algorithms. The system demonstrates the application of existing graph theory algorithms in reserve design problems by illustrating the similarity and differences between classic graph theory problems and those faced by planning officials. Notions of connectivity and parsimony important to researchers in both fields are explicitly addressed.     

河西走廊盐碱地治理模式研究

河西走廊由于其独特的地形、地质、水文结构和干旱气候条件,极易形成盐渍化土地,利用工程改良模式、草畜培肥地力模式、林药栽培模式治理盐碱地,使盐碱地资源得到持续利用,取得了较好的效益。     

甘肃河西走廊高效节水灌溉关键问题浅析

在分析河西走廊高效节水灌溉现状的基础上,提出了大规模发展高效节水灌溉其自身存在的、以及可能引发或伴生的相关问题,初步分析了解决这些问题的途径。在河西走廊地区具有很强的针对性,在其他地区具有借鉴参考价值。     

河西走廊水利工程风沙危害防治措施体系研究

河西走廊地处西北内陆河流域,由于气候干旱、风大沙多,风沙对水利工程的填埋淤积非常严重。在对河西走廊水利工程风沙危害现状全面调查的基础上,按风沙危害成因,将危害类型划分为以风沙流为主、以河道水力输沙为主和以沙丘前移为主的三种形式,并分别以榆林河水库及干渠、双塔水库和解放村水库为例,研究建立了不同危害类型的防治措施配置体系,以期延缓风沙对当地水利工程的填淤过程。