中国城镇化包容性发展中的公共投资支持影响研究

本文通过构建城镇化包容性发展指标体系，测度出中国2003—2015年30个省级区域的城镇化包容性发展指数，经莫兰指数检验发现其具有显著的空间正相关性。进而采用空间计量模型，基于户籍制度改革背景，从生产性公共投资、社会性公共投资与环保性公共投资三个方面研究公共投资对城镇化包容性发展的影响。研究结果表明，生产性公共投资与社会性公共投资对城镇化包容性发展均存在显著的正向支持作用，且户籍制度改革变量与二者产生了正向的交互作用，说明随着对人口流动限制的放松，生产性公共投资与社会性公共投资对城镇化包容性发展的支持作用有所增强，但环保性公共投资未能表现出显著的支持作用。在未来城镇化进程中，应当优化调整中国公共投资的行业结构与区域结构，从而更好地提升城镇化包容性发展水平。     

基于多源数据的自然生态空间分类体系构建及其识别

研究目的:探讨市县尺度下自然生态空间分类体系和多源数据下自然生态空间识别方法。研究方法:采用归纳比较法构建自然生态空间分类体系,通过综合分析法建立多分类体系转换机制,运用GIS空间分析法识别自然生态空间。研究结果:(1)市县级自然生态空间是指生产性空间和承载性空间以外,以发挥土地生态系统服务功能为主导,以提供生态产品为主,对维护区域生态系统稳定性,保障区域生态安全格局具有重要作用的用地空间;(2)自然生态空间可分为基础生态空间和人工生态空间两个一级类,10个二级类,26个三级类;(3)2015年鹤壁市自然生态空间总量606.08 km~2,其中基础生态空间554.41 km~2,人工生态空间51.67 km~2。研究结论:依据市县尺度自然生态空间分类体系,运用多源数据融合转换识别方法能快速准确识别自然生态空间数量和空间分布。     

The evolving 5G case study in United States unilateral spectrum planning and policy

This paper tracks increasingly aggressive initiatives by the United States government to reallocate spectrum on an expedited and unilateral basis well before conclusion of inter-governmental coordination. Rather than embrace the customary commitment to achieve consensus on global spectrum allocations at the International Telecommunication Union (“ITU”), the Federal Communications Commission (“FCC”) has auctioned off large blocks of frequencies for the next generation (“5G”) of wireless services.The FCC might have framed its first 5G auction, reassigning Ultra High Frequency (“UHF”) spectrum, as a one-time deviation from compliance with long standing, intergovernmental coordination procedures. These frequencies have ideal signal propagation characteristics and the Commission could use financial incentives—unavailable in most nations—to expedite “repacking” by incumbent broadcasters willing to move, share or abandon spectrum in exchange for ample financial compensation. However, the FCC has continued to auction off 5G spectrum on grounds that it must find ways to abate an acute shortage of wireless bandwidth and doing so will regain or maintain global leadership in wireless technologies. This paper offers a critical rebuke to unilateral spectrum management, because the short-term benefits expected by the U. S. government likely will be offset by countervailing harms to 5G manufacturers, carriers and consumers. The paper tracks fractious preparation for the ITU's 2019 World Radio Conference by the U.S. delegation and the mixed record achieved there. Additionally, the paper explains how injecting trade, industrial policy and national security issues at the ITU can trigger more delays and disputes, including possible retaliation by nations displeased with U.S. efforts to subvert traditional technology optimization goals.A worst case scenario has the ITU deadlocked and unable to reach closure on “mission critical” spectrum planning issues at World Radio Conferences, convened every four years. The paper concludes that costs and likely challenges to the efficacy and legitimacy of the ITU will reduce the benefits accruing from the FCC's unilateral, spectrum planning campaign.     

建筑工程造价控制及优化措施探析

在建筑工程项目中,严格控制工程造价,可以取得较好的经济效益。要做好建筑工程的造价控制工作,为企业赢得良好的经济效益,必须要求企业内部多方面进行协调与配合。     

集装箱船初稳性高度优化模型的建立

为解决目前集装箱配积载中尚需结合人工经验来进行箱位选配的问题,通过研究集装箱船配积载前重心距基线高,运用集装箱船初稳性高度计算原理,结合集装箱船的结构特点,建立集装箱船初稳性高度优化模型。运用交互式的线性和通用优化求解器编写程序,其研究成果将为实现集装箱船自动化配积载目标提供理论基础。     

浅谈直接空冷机组乏汽余热利用改造后的安全运行

汽轮机乏汽余热利用是目前火力发电厂节能降耗,增加供热面积的一项重要工程,本文结合我厂实际对乏汽余热利用改造工程的优化进行了介绍,对热泵投运过程中及投运后对机组安全运行的影响和采取的措施进行了总结。     

土建工程现场管理优化策略分析

本文在分析目前土建工程现场管理主要内容及所存在问题的基础上,对优化土建工程现场管理提出合理化建议。     

对体育比赛场馆项目流程管理的若干思考

该文章在简要介绍流程管理的定义后,引出体育比赛场馆项目流程管理的相关定义,进而分析阐明了体育比赛场馆建设项目流程管理的现状,并对当前市场上存在的流程管理方面的问题进行了论述,最后针对这些问题提出一系列相应的优化措施,为体育比赛场馆建设项目的流程管理提供了借鉴。     

优化生产环节和劳动组织管理提高掘进单进水平

本文介绍了双马煤矿的建设情况,对矿井建设过程中制约掘进单进水平的原因进行了分析,提出优化生产环节、改进施工工艺和优化劳动组织管理、提高劳动工效的具体措施。     

Robust Markowitz mean‐variance portfolio selection under ambiguous covariance matrix

This paper studies a robust continuous‐time Markowitz portfolio selection problem where the model uncertainty affects the covariance matrix of multiple risky assets. This problem is formulated into a min–max mean‐variance problem over a set of nondominated probability measures that is solved by a McKean–Vlasov dynamic programming approach, which allows us to characterize the solution in terms of a Bellman–Isaacs equation in the Wasserstein space of probability measures. We provide explicit solutions for the optimal robust portfolio strategies and illustrate our results in the case of uncertain volatilities and ambiguous correlation between two risky assets. We then derive the robust efficient frontier in closed form, and obtain a lower bound for the Sharpe ratio of any robust efficient portfolio strategy. Finally, we compare the performance of Sharpe ratios for a robust investor and for an investor with a misspecified model.