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。     

基于改进粒子群算法的无人机航迹规划

针对当前基本粒子群算法无人机航迹规划在后期收敛速度比较慢、效率不高、易陷入局部最优等问题,提出一种改进粒子群算法。首先,在迭代前期和后期分段设置惯性权值的调整,实现粒子惯性和寻优行为的平衡;其次,设置一个定值与相邻2次适应度函数最优值比较策略,防止陷入局部最优;最后,引入遗传算法的交叉、变异机制,得出更优的结果。并通过仿真验证了改进粒子群算法在三维空间航迹规划的有效性和可行性。结果表明,与其他航迹规划算法相比,新算法具有路径长度更短、耗时更少、路径更平滑等优点,加快了收敛速度,提高了航迹规划效率和稳定性。因此,改进算法的航迹规划可得到满足约束关系的最优航迹,对实现自主飞行有重要的参考价值。     

Optimal granularity for portfolio choice

Many optimization-based portfolio rules fail to beat the simple 1/N rule out-of-sample because of parameter uncertainty. In this paper we suggest a grouping strategy in which we first form groups of equally weighted stocks and then optimize over the resulting groups only. This strategy aims at balancing the trade-off between the benefits from optimization and the losses from estimation risk. We rely on Monte-Carlo simulations to illustrate the performance of the strategy, and we derive the optimal group size for a simplified setup. Furthermore, we show that estimation risk also has an impact via the criterion by which the assets are sorted into groups (like the expected excess returns or betas), but does not negate the grouping approach. We relate our work to linear asset pricing models, and we conduct out of sample back-tests in order to confirm the validity of our grouping strategy empirically.     

耕地利用多功能权衡关系测度与分区优化 ——以河南省为例

研究目的:分析河南省耕地利用多功能空间分布特征、多功能权衡关系区域差异,提出分区优化管控措施。研究方法:耦合协调度方法、权衡强度方法。研究结果:(1)河南省各县(区)耕地利用多功能呈现明显的空间异质性,中原城市群生产功能和社会保障功能优势明显,黄淮平原生产—生态功能强;(2)多功能协调度、权衡强度空间差异明显,中原城市群和豫北地区协调程度高、权衡强度低;(3)全省可耕地划分为多功能高协调区、多功能低协调区、单功能主导区、生产—生态协调区、生产—社会保障协调区、生态—社会保障协调区6大区域。研究结论:研究结果与河南省区域发展战略定位相符,揭示河南省耕地利用多功能分布和权衡关系,划分不同类型区并提出优化建议,为河南省农业空间管控提供决策支持。