Role of informal sector recycling in waste management in developing countries

Many thousands of people in developing country cities depend on recycling materials from waste for their livelihoods. With the focus of the Millennium Development Goals on poverty reduction, and of waste strategies on improving recycling rates, one of the major challenges in solid waste management in developing countries is how best to work with this informal sector to improve their livelihoods, working conditions and efficiency in recycling.The general characteristics of informal recycling are reviewed, highlighting both positive and negative aspects. Despite the health and social problems associated with informal recycling, it provides significant economic benefits that need to be retained. Experience shows that it can be highly counterproductive to establish new formal waste recycling systems without taking into account informal systems that already exist. The preferred option is to integrate the informal sector into waste management planning, building on their practices and experience, while working to improve efficiency and the living and working conditions of those involved. Issues associated with integrating informal recycling into the formal waste management sector are discussed.     

基于遗传粒子群算法的堆垛机作业路径优化

通过查慎行对《瀛奎律髓》中陆游诗歌的评点可以看出，他在章法、用典、字法、句法、对仗等方面对陆游诗歌多有称赏，对陆游学古不化及艺术上的瑕疵亦多有批评，总体上体现出较为客观的批评态度。在查慎行的诗学理论体系中，陆游的地位经历了一个由高到低的过程。查慎行对自己青年时期偶像的批评与颠覆，体现出其晚年诗学理论的转变与成熟。     

“托物取象”与诗性言说——论古典文论对李健吾文学批评的影响

李健吾的文学批评在古典文论的影响下形成了独树一帜的批评风范.他强调直觉感悟,善于营造意象,运用比喻、象征、类比等手法传达阅读感受,形成“托物取象”的论证方法;形式自由,短小精悍,文字飘逸、饱含诗情,形成了诗性言说下的散漫文体与诗意语言风格.     

Interval Partitioning Arising from Size-Biased Picking

We consider the following fragmentation model of the unit interval 𝕀. We start fragmenting 𝕀 into two pieces with uniform random sizes. One of these two subintervals is then chosen at random according to a β-size-biased picking procedure, β ∈ ?. This particular tagged fragment is next broken into two random pieces, one of which is chosen accordingly at random for further splitting; the process is then iterated independently. This model constitutes a recursive β-partitioning procedure where splitting occurs only at one of the two fragments formed in the previous step of fragmentation. We investigate some statistical features of this model.     

A Flexible Evaluative Framework for Order Picking Systems

This paper develops a novel framework to evaluate the integral performance of order picking systems with different combinations of storage and order picking policies. The warehousing literature on order picking mostly considers minimizing either elapsed time or distance as the sole objective, whereas warehouse managers in a supply chain have to look beyond single‐dimensional performance and consider trade‐offs among different criteria. Thus managers still need a unified and efficient framework to select a portfolio of appropriate order picking policies from a multi‐criteria and contextual perspective. Our framework—combining data envelopment analysis, ranking and selection, and multiple comparisons—provides an efficient methodology to simultaneously analyze several interrelated problems in order picking systems with multiple performance attributes, such as service levels and operational costs. We demonstrate our approach through comprehensive evaluations of order picking policies in three low‐level, picker‐to‐parts rectangular warehouses facing demand variations.     

樱桃萝卜在三亚市试种试验

在大田条件下,引种十个樱桃萝卜品种,结合其生长情况,对樱桃萝卜在三亚种植的栽培技术及病虫害的管理进行了研究.结果表明:萨丁和笑脸两个樱桃萝卜品种在三亚种植时,生长情况、单株根重、群体产量都表现较好,可以在三亚进行大面积推广种植.这两个品种的单株根重还不到7g,栽培管理技术需进一步完善.     

Efficient formation of storage classes for warehouse storage location assignment: A simulated annealing approach

Class-based storage policy distributes products among a number of classes and for each class it reserves a region within the storage area. The procedures reported in the literature for formation of storage classes primarily consider order-picking cost ignoring storage-space cost. Moreover, in these procedures items are ordered on the basis of their cube per order index (COI), and items are then partitioned into classes maintaining this ordering. This excludes many possible product combinations in forming classes which may result in inferior solutions. In this paper, a simulated annealing algorithm (SAA) is developed to solve an integer programming model for class formation and storage assignment that considers all possible product combinations, storage-space cost and order-picking cost. Computational experience on randomly generated data sets and an industrial case shows that SAA gives superior results than the benchmark dynamic programming algorithm for class formation with COI ordering restriction.     

自动化立体仓库中出入库任务顺序与出库位置选择集成优化研究

具有多个出口的自动化立体仓库系统是一种将存储和分拣相结合的新型仓储技术,其最典型的特征是在货架底层有很多个出库位置以供取货人员分拣。研究此系统中出入库任务排序与出口选择的集成优化问题,以最小化堆垛机完成所有任务的移动距离为目标,将此问题转化为一个混合整数规划模型。根据问题的特点设计了两阶段启发式算法求解此问题,数值结果表明设计的算法能在较短时间内给出近似最优解,同时与企业常用的先到先服务方法相比,该算法可以缩短超过20%的移动距离。     

樱花文化与日本

樱花文化已成为日本特有的一种文化。从樱花的花名、‘崂前慄’‘花尒’以及樱花与武士精神各个方面可以看出樱花代表着日本国民，樱花一起绽放，一起凋谢，体现了日本国民的团结与凝聚力。     

Order batching in a pick-and-pass warehousing system with group genetic algorithm

An order batching policy determines how orders are combined to form batches. Previous studies on order batching policy focused primarily on classic manual warehouses, and its effect on pick-and-pass systems has rarely been discussed. Pick-and-pass systems, a commonly used warehousing installation for small to medium-sized items, play a key role in managing a supply chain efficiently because the fast delivery of small and frequent inventory orders has become a crucial trading practice because of the rise of e-commerce and e-business. This paper proposes an order batching approach based on a group genetic algorithm to balance the workload of each picking zone and minimize the number of batches in a pick-and-pass system in an effort to improve system performance. A simulation model based on FlexSim is used to implement the proposed heuristic algorithm, and compare the throughput for different order batching policies. The results reveal that the proposed heuristic policy outperforms existing order batching policies in a pick-and-pass system.