Butterflies (Lepidoptera: Papilionoidea) of Mount Kilimanjaro: family Pieridae,subfamily Coliadinae

This paper forms part of a series on the butterfly fauna of Mount Kilimanjaro. Three genera (Catopsilia, Colias and Eurema) with eight species of Coliadinae are believed to occur within the main forest zone. However, of these, one or two may prove to be no more than variants of a third species, Eurema desjardinsii. A fourth conventionally recognized member of the complex may occur on the lower slopes below 1800 m. The widespread species Eurema hecabe occurs on the lower slopes, but records are sparse, and no records of its close relative Eurema floricola, with which it has often been confused, have been found. The need for original field and laboratory research on the taxonomy of African Eurema species is stressed. Keys to adult Coliadinae found in Tanzania, with colour illustrations, are included as online supplementary material.     

可变提前期的模糊随机连续盘点策略

考虑到现实库存管理中模糊随机现象,研究了含可变提前期的模糊随机连续盘点的最小成本模型。运用模糊随机变量的期望值理论,得到了其模糊期望模型;采用符号距离法得出了模糊随机缺货量的估计值,从而推导出了模糊期望成本的符号距离解析式。通过这一模型,可以找到使总成本最小的最优提前期和最优订货量。     

Improved local inventory and regional contextualization for anuran (Amphibia) diversity assessment at an endangered habitat in southeastern Brazil

Amphibians are suffering population declines around the world and the main causes are related to human activities, especially those involving direct habitat destruction. On the other hand, we are far behind in our knowledge of species distribution, natural history and even taxonomy. Some areas are under high levels of threat due to their economic relevance, as is the case for the Quadrilátero Ferrífero, a biodiverse area that is rich in iron deposits in the southernmost highlands of the Espinhaço Mountain Range, in southeastern Brazil. Using four lakes in the Quadrilátero Ferrífero as an example, we aimed to employ two approaches that we believe can improve short-term species inventories such as those needed to meet legal requirements for potentially impacting enterprises (e.g. mining). These approaches were (1) combination of tadpole and adult frog inventories and (2) regional contextualization of local species assemblages. We found adult frog and tadpole sampling to be complementary and representative of all anuran life stages. We also found the studied habitats to be considerably different from all other sampled habitats in the Quadrilátero Ferrífero (which also differed substantially among them). This high spatial heterogeneity could not be explained by geographic distance, even accounting for the effects of different types of bodies of water and sampling methods among sites. These findings have important conservation implications. Thorough inventories including both adult and tadpole stages are recommended for any new potentially destructive enterprise to be implemented in the Quadrilátero Ferrífero, because endemic species and unique anuran assemblages are likely to be lost.     

考虑需求关联性的多供应商电商库存分配研究

需求关联性现象普遍存在于顾客购买行为中，然而大多数库存管理方面的研究假设产品需求相互独立，忽视关联性造成的影响，可能导致严重的缺货现象发生。针对存在需求关联性情况下具有库存容量限制的多供应商电商库存分配问题，应用FP-Growth算法从订单数据库中挖掘得到关联规则，并将关联规则抽象为一种约束，建立双目标随机规划数学模型，通过分段线性拟合方法对非线性目标函数和约束进行处理。采用非支配排序遗传算法(NSGA-Ⅱ)对模型进行求解，基于“先知种群”改进种群初始化过程，以提升算法收敛速度。使用真实数据的数值实验表明，基于关联规则的库存分配模型能以小幅度增加运营成本为代价，显著减少缺货数量。最后对库存容量、关联规则置信度和供应商个数进行敏感性分析，进一步为电商平台管理者提供了参考。     

随机梯度估计及其在系统管理中的应用

随着信息技术与系统管理的深度融合发展，蒙特卡洛仿真技术和随机梯度估计方法在系统管理中受到越来越多的重视。梯度估计是优化复杂系统结构、估计复杂系统参数、度量和控制风险的重要工具。由于梯度估计包含比系统表现估计更多有用的信息，如何对随机梯度进行准确估计在随机仿真领域得到了广泛的关注，并且它是基于梯度的优化方法中的核心问题。对常用的随机梯度估计方法进行了梳理，并举例介绍了其在系统管理中应用的主要挑战、求解思路及对管理学研究的启示，以期为系统管理提供理论和方法学基础。