岭南园林和江南园林美学特征的比较

本文从环境、功用、性格、艺术、文化五个方面,对岭南园林和江南园林美学特征进行了比较,提炼出二者不同的个性特点,提出了园林是文化的载体。     

Hybrid Recommender System Using Systolic Tree for Pattern Mining

A recommender system is an approach performed by e-commerce for increasing smooth users’ experience. Sequential pattern mining is a technique of data mining used to identify the co-occurrence relationships by taking into account the order of transactions. This work will present the implementation of sequence pattern mining for recommender systems within the domain of e-commerce. This work will execute the Systolic tree algorithm for mining the frequent patterns to yield feasible rules for the recommender system. The feature selection's objective is to pick a feature subset having the least feature similarity as well as highest relevancy with the target class. This will mitigate the feature vector's dimensionality by eliminating redundant, irrelevant, or noisy data. This work presents a new hybrid recommender system based on optimized feature selection and systolic tree. The features were extracted using Term Frequency-Inverse Document Frequency (TF-IDF), feature selection with the utilization of River Formation Dynamics (RFD), and the Particle Swarm Optimization (PSO) algorithm. The systolic tree is used for pattern mining, and based on this, the recommendations are given. The proposed methods were evaluated using the MovieLens dataset, and the experimental outcomes confirmed the efficiency of the techniques. It was observed that the RFD feature selection with systolic tree frequent pattern mining with collaborative filtering, the precision of 0.89 was achieved.     

“迭代-降维-梯度搜索法”求解Dobbins模型参数研究

文章介绍了用“迭代－降维－梯度搜索法”求解Dobbins模型参数的研究成果。该法能解决目前存在的用梯度法搜索参数时误差较大及用“计算机扫描计算－图解－梯度搜索法”寻求参数时计算量较大的问题。     

A computational study of parametric tabu search for 0–1 mixed integer programs

We present a computational study of parametric tabu search for solving 0–1 mixed integer programming (MIP) problems, a generic heuristic for general MIP problems proposed by Glover [Glover F. Parametric tabu-search for mixed integer programs. Computers and Operations Research 2006; 33: 2449–94.]. This approach solves a series of linear programming problems by incorporating branching inequalities as weighted terms in the objective function. New strategies are proposed for uncovering feasible and high-quality solutions and extensive computational tests are performed on instances from the literature.     

ILP heuristics and a new exact method for bi-objective 0/1 ILPs: Application to FTTx-network design

Heuristics and metaheuristics are inevitable ingredients of most of the general purpose ILP solvers today, because of their contribution to the significant boost of the performance of exact methods. In the field of bi/multi-objective optimization, to the best of our knowledge, it is still not very common to integrate ILP heuristics into exact solution frameworks. This paper aims to bring a stronger attention of both the exact and metaheuristic communities to still unexplored possibilities for performance improvements of exact and heuristic multi-objective optimization algorithms.We focus on bi-objective optimization problems whose feasible solutions can be described as 0/1 integer linear programs and propose two ILP heuristics, boundary induced neighborhood search (BINS) and directional local branching. Their main idea is to combine the features and explore the neighborhoods of solutions that are relatively close in the objective space. A two-phase ILP-based heuristic framework relying on BINS and directional local branching is introduced. Moreover, a new exact method called adaptive search in objective space (ASOS) is also proposed. ASOS combines features of the ϵ-constraint method with the binary search in the objective space and uses heuristic solutions produced by BINS for guidance. Our new methods are computationally evaluated on two problems of particular relevance for the design of FTTx-networks. Comparison with other known exact methods (relying on the exploration of the objective space) is conducted on a set of realistic benchmark instances representing telecommunication access networks from Germany.     

关于并发系统分支互模拟关系发散性保持的研究

带发散性说明的分支互模拟是van Glabbeek和Weijland提出的一个概念,并被用来定义等价关系.该等价关系应该是最弱的一个发散性保持的并且满足分支互模拟性质的等价关系.然而在概念提出时并没有提供这些重要性质的证明,并且我们认为在原定义的基础上这个证明是不显然的.本文通过co-induction的手段利用染色迹的概念定义了着色完全迹等价,并证明该等价关系是最弱的一个保持发散的并且满足分支互模拟性质的等价关系.然后我们证明了着色完全迹等价关系和≈_b^△是相同的,因而补充了van Glabbeek和Weijland的工作,即证明了≈_b^△是最弱的一个保持发散的并且是满足分支互模拟性质的等价关系.     

多元因子分析模型在河流健康评价中的应用——以苏子河水质特性研究为例

为顺应河流生态可持续发展,提出健康河流、生命河流等概念,维持河流生态系统健康已经成为流域综合管理的必然趋势。综合运用水文学、水力学、泥沙地貌学和水生生态学的基本理论和方法研究河流生态健康的表征因子,确定各因子的阈值,建立流域性水体水质可续发展评价体系。以河流可持续发展为基础,引用代表性的相关指标进行筛选,对流域水质指标进行数值化分析,以苏子河流域水质特性为研究对象,选取出评估河流健康状况的环境因子,客观反映出中小河流域健康状况,为河流的可持续管理和生态环境建设提供参考。     

南水北调中线小南河串流片防洪水位计算

传统的多河流串流计算主要采用水库联调的方法,把串流的各条河流概化为静态水库,库水位水平且不考虑横向流动。为解决串流区水流的横向流动及水面线并不总像库水位一样水平的问题,采用二维非恒定流数学模型计算串流区洪水演进。通过概化地形、考虑入流、糙率、边界条件和水流的横向流动等因素,计算出了整个串流区域的水面线、水深、流速、出流等水力要素,并给出洪水演进模拟图,为确定河流与总干渠交叉建筑物的规模、总干渠左岸沿线水面线和对沿线村庄、农田的防洪影响提供了可靠的依据。     

用殷钢波导控制相控阵天线的监测精度

有效地控制某系统相控阵天线的指向精度,是保证整个系统精确定位的关键问题。这里介绍了如何利用殷钢材料的温度特性以及选用殷钢材料的波导来做监测歧管,保证监测精度的设计依据。     

论溪落渡水电站的战略地位

溪落渡水电站是金沙江上最大的一座巨型电站,装机容量1200~1500万kW,除发电外兼有防洪、拦沙、改善下游航运等综合利用效益。通过对金沙江水电基地在我国经济建设中的地位和作用;溪落渡水电站在金沙江水电基地开发中的地位和作用、在“西电东送(包括南送)”中的地位和作用以及在长江上游水电基地中的地位和作用等论述,希望引起有关领导和决策部门的重视,加快溪落水电站前期工作的进程和促进金沙江水电基地的开发。