一种飞行器集群管理和任务分离的组网方法

组网是卫星、无人机等飞行器集群实现协同的基础。传统自组织组网技术针对地面随机移动场景设计，不适用于拓扑和传输根据任务变化的飞行器集群场景，为此设计了一种管理与任务分离的组网方法，将网络分为管理面和任务面两个逻辑层面，管理面负责拓扑发现、路由建立、任务规划等基础组网功能，任务面负责任务执行过程中的数据传输功能。管理面和任务面实行不同的组网策略，从而使得网络的传输性能根据管理和任务执行的不同需求进行优化，以减少协议开销及降低传输自干扰。     

我国物流业转型升级研究综述

中国经济已经到了只有转型升级才能持续健康发展的关键阶段,产业转型升级在国家政策文件和研究文献中出现的词频较高。文章以我国物流业为研究对象,从现有涉及到物流业转型升级方面的文献挖掘有效信息,梳理我国物流业转型升级研究的历史脉络,从供应链与价值链、产业集群、现代科学技术应用和产业联动四个视角对现有的物流业转型升级文献进行了总结和归纳,并从物流业转型升级的动力研究、阶段性划分研究和演进规律研究三个方面指出了现有文献的研究不足和以后可能的研究方向。其中,供应链与价值链视角侧重于物流企业的纵向角度,产业集群视角侧重于物流企业的横向角度。文章对于物流企业战略设计、政府政策的制定和理论研究具有一定的参考作用。     

Trade, foreign firms and economic policy in Indonesian and Thai manufacturing

This paper first examines the rapid growth and changing composition of manufactured exports in Indonesia and Thailand, highlighting the rapid growth of office and computer machinery and electric machinery, somewhat slower growth of non-electric and transportation machinery, as well as the low growth of previously large exports of textiles apparel. Second, the important contributions of foreign multinational enterprises (MNEs) to export growth in the machinery industries, particularly in electric, office, and computing machinery, are documented. Third, the paper describes trade policies in all these industries in some detail, emphasizing how low protection was a key facilitator of rapid export growth in the MNEs that dominated the electric, office, and computing machinery industry, while high protection reduced incentives to export among MNEs in the transportation machinery industry.     

基于聚类分析电信运营企业仓库布局优化研究

以某电信运营企业为例,在现场调研的基础上,分析了企业仓库布局的主要问题,应用聚类分析方法,提出了仓库布局优化方案,并进行了方案的综合评价.     

论国企留住人才的有效措施

未来经济的竞争主要是科学技术与人才的竞争,而归根结底是人才的竞争。人才是当今以及未来时代竞争的焦点,如何吸引人才而避免人才的流失成为企业,尤其是国有企业所面临的最严峻的课题。根据国企人才流失的最主要原因和人才最看重的是个人发展空间和机会,从而为国企如何为人才提供个人发展空间和机会提出了一些对策和建议。     

关于产业集群技术创新的若干问题

产业集群的蓬勃发展带动了我国区域经济迅速发展,但当前我国产业集群中企业创新不足的问题日益显现,阻碍了产业集群的进一步发展,而要强化产业集群技术创新,关键是探寻技术创新的实现路径,整合创新要素,做出有利于推进产业集群技术创新的战略选择.     

Robustness issues in multilevel regression analysis

A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood.     

从供需层面看中国第三方物流问题

随着中国经济的发展，提供第三方物流服务的物流公司纷纷涌现出来。同时，与第三方物流相关的一些问题也随之出现．针对这种情况．我们建立了第三方物流经济模型，从供需层面来分析中国第三方物流中存在的问题．找出问题存在的根本原因，并且对物流企业的建设提出一些建议和解决方案。     

灰色聚类综合评价方法在住宅建筑方案选优中的应用

阐述了基于灰色聚类原理开发出的一种综合评价方法，其应用于住宅建筑方案选优，既可选出相对最优方案，又可直观地评出其属于何种等级的灰类。