Complex Network of Aviation E-Services in the Belt and Road Initiative: A Heuristic Study of Small Data based on Block Modeling

ABSTRACT

The aviation e-service system is an important part of support for business communication in regions covered by Belt and Road initiative. In exploring the role of airline companies in this system, we examine the structure of the network, which consists of airlines interconnections based on small data of individual attributes of aviation companies in aviation e-services, and study these interconnections across different groups using block modeling. The heuristic solution of airline companies in development of international communication and cooperation is further discussed. Among our policy implications for global managers, we suggest the enhancement of cross-regional cooperation among airlines.     

Entanglements in multispecies voluntourism: conservation and Utila's affect economy

Abstract

Through a case study of conservation voluntourism this article brings together critical political ecology, multispecies ethnography, and studies of humanitarian tourism to advance a political ecology of multispecies conservation voluntourism. The article presents multispecies conservation voluntourism as a field that produces and is produced by an “affect economy”, or an economy based on the exchange or trade in the relational. Since the mid-1990s, life on Utila, Honduras, a popular discount backpacker scuba destination located along the Mesoamerican Barrier Reef, has been deeply transformed by the growth of dive tourism, the ecological destruction it has produced, and now the conservation voluntourism industry emerging in its wake. Seventy percent of Utila is comprised of mangroves and associated wetlands, home to several endangered and endemic species. Using examples of whale shark tourism, lionfish hunts, and iguana tracking, this article shows how conservation organizations operate as affect generators, enabling the privilege of engaging in multispecies encounters. Engaging in multispecies conservation voluntourism produces value in the form of cultural capital which is then exchanged for material outcomes by volunteers in the global economy; at the same time, this form of voluntourism obscures local relationships to nature and alters multispecies assemblages from past configurations.     

军用集装箱三维装载的优化方法

以军用集装箱装载为研究对象，在考虑实际应用中的一些约束条件下，构造了军用集装箱的装载优化模型，提出了一种军用集装箱三维装载的启发式算法。该算法采用了整体装填、空间合并等策略，考虑了装载方向、优先顺序、重心等约束条件。最后对一个案例进行了计算与分析，验证了该模型的有效性，并且利用3ds max得到了装载方案的三维图。     

供应链管理中的两层规划算法

文章概述两层规划问题在交通领域、资源分配、委托代理以及供应链管理中的应用并讨论了线性和非线性两种两层规划问题,总结了极点算法、下降迭代、惩罚函数和分支定界算法,并进行了评价,最后进一步探讨了两层规划问题的应用前景和算法的发展方向。     

考虑线路安排的物流配送方案模型及其算法研究

在分析车辆路径问题现有启发式算法的基础上，建立了考虑线路安排的物流配送方案模型，并提出了求解该问题的一种搜索算法，实验结果表明，该算法可有效求得问题的优化解或近似优化解，且具有运算速度快、算法简便的特点。     

配送计划的优化编制方法

讨论了在时间、距离和载重量等多种约束条件下，编制配送计划的优化方法。先给出配送问题的数学模型，并设计了一个带时间和距离约束条件的启发式算法来求解该模型，求得问题的近似解；然后再采用分枝定界法得到配送问题的最优解：最后，考查近似解与最优解在总的运行距离的相对误差，以此检验这个近似解的有效性。     

越库作业调度问题及其启发式算法研究

主要研究两台机器环境下的以加权完工时间和为目标函数的越库调度问题。首先针对两机器越库调度问题进行研究与分析,给出该问题最优解的若干性质;其次,基于最优解的性质,提出求解该问题的启发式算法,并在此基础上对所给算法进行改进;最后,通过数值实验与动态规划算法比较,证明所给算法及其改进算法的有效性。     

How group efficacy mediates the relationship between group affect and identification

This study examines the mediating role of group efficacy on the relationship between group affect and group identification by integrating the collective cognition process. Using a sample of forty-seven work groups in Study 1, the results show that group efficacy fully mediates the relationship between positive and negative group affect and group identification. Study 2 applies a two-wave panel design to verify the impact of group efficacy on group identification. The results of Study 2 indicate that group efficacy relates positively to the development of group identification. The implications for theory and practice are discussed.     

单车场无时间窗甩挂运输车辆调度的启发式算法

考虑了牵引车空驶、带空挂车行驶和带重挂车行驶所引起的成本差异，定义了牵引车运行成本的概念，将总运行成本最小作为调度方案优劣的判别指标，并同时考虑牵引车数量最少。将牵引任务分为四种类型，定义了任务链、虚拟任务、链内交叉和链间交叉的概念，提出了一种求解该类单车场甩挂运输车辆调度无时间窗约束的启发式算法，包括初始调运方案、链内优化、空车调运交叉、牵引车数量优化和链间交叉。最后给出了仿真算例，算法优化后的最终方案与初始方案相比，牵引车数量减少，总运行成本降低，验证了算法的有效性和可行性。     

Information and Investor Behavior Surrounding Earnings Announcements

The goal of this paper is to analyze the impact of annual earnings announcements on the market through the order flow data in addition to the usual transaction data. In this respect, examining order flow data can potentially reveal valuable information that is not available from transaction data. In fact, the data allow us to test hypotheses about asymmetric information and investor behavior and to test if the behavior varies with investor sophistication. In addition, the paper tries to identify the determinants of the impact on a firm's value using assumptions about investor behavior.